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A series of nine new soft salts based on two platinum(II) complexes, namely ([Pt(C^N)(CN)2]−[Pt(C^N)(en)]+) (en = ethane-1,2-diamine), has been developed and synthesized. Their photophysical properties in both solution and the solid state were described. All soft salt complexes exhibit phosphorescence emission with PLQY in the solid state up to 0.36. Most of these materials displayed aggregation-induced emission (AIE) or aggregation-induced emission enhancement (AIEE) in water/DMSO solutions as the water ratio increased. Structure–property relationships were analyzed in relation to emission properties. The presence of the free nitrogen atoms in soft salt complexes with a C^N pyrimidine-based ligand allowed for reversible sensitivity to acidic vapors, resulting in the quenching of phosphorescence emission. Additionally, for selected soft salts, we described reversible vapochromism behaviour, making these new materials interesting for multi-detection purposes in anti-counterfeiting applications. [ABSTRACT FROM AUTHOR]

The preparation of Fe(II) complexes combining monodentate NCX− (X = S or Se) and the tetradentate Schiff base chiral ligands RR-L1 and SS-L1 = (RR- or SS-L1 = 1R,2R or 1S,2S)-N1,N2-bis(pyridin-2-ylmethylen)cyclohexane-1,2-diamine in acetone results in an unexpected reaction. Thus, four enantiomerically pure compounds of formulas [Fe(RR-S-L2)(NCX)2] and [Fe(SS-R-L2)(NCX)2] (X = S or Se) are formed by the new asymmetrical ligand L2. In L2, one acetone solvent molecule is incorporated into the ligand forming a bond with the C atom of one of the two CN imine groups of L1, which is transformed into an amine (Mannich reaction). This reaction is diastereoselective as the incorporation of acetone leads to an asymmetric C adjacent to the NH group with opposite chirality S- or R- to that of the cyclohexane carbons (RR- or SS-, respectively). Therefore, L2 contains three C chiral centers. Structural and magnetic characterization of these compounds demonstrates that they show in the bulk a gradual spin-crossover behavior and LIESST effect. Interestingly, the presence of an intramolecular hydrogen bond between the integrated acetone molecule and the NH group can trigger a secondary stimuli-responsive behavior in the system. Therefore, by changing the solvent polarity, the color of the complex in solution can be easily tuned. [ABSTRACT FROM AUTHOR]

Applying molecular design to chiral organo-Zn2+ complexes, a new pair of chiral heteroleptic bis-pyrazolonate-Zn2+ enantiomers [Zn(PMBP)2(1R,2R-Chxn)] (R,R-Zn2+ ; HPMBP = 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone and 1R,2R-Chxn = (1R,2R)-cyclohexane-1,2-diamine) and [Zn(PMBP)2(1S,2S-Chxn)] (S,S-Zn2+ ; 1S,2S-Chxn = (1S,2S)-cyclohexane-1,2-diamine) have been synthesized and characterized in terms of photophysical and thermodynamic properties. In addition to a small Flack parameter (0.05(3)) associated with the solid-state elucidation of S,S-Zn2+ , the circular dichroism (CD) and circularly polarized light (CPL) spectra for the chiral Zn2+ enantiomers show perfect mirror symmetry, establishing that the enantiopure 1,2-diamines successfully induce the optical isomerism of R,R-Zn2+ and S,S-Zn2+. As a result of the combined strong chiral induction capability of chiral 1,2-diamines and excellent photophysical properties of the pyrazolone ligand (PMBP)−, the two Zn2+ enantiomers exhibit high-quality pure blue fluorescence (ΦPL = 9–10%) and significant CPL activity (‖glum‖ = 0.0065–0.0068). The heteroleptic strategy adopted in this study offers a new route to develop high-performance chiroptical luminophores. [ABSTRACT FROM AUTHOR]

Au(III) bis(pyrrolide-imine) chelates are emerging as a class of versatile, efficacious metallodrug candidates. Here, we synthesised two enantiopure chiral ligands H2L1 and H2L2 (tetradentate cyclohexane-1,2-diamine-bridged bis(pyrrole-imine) derivatives). Metallation of the ligands with Au(III) afforded the chiral cationic complexes AuL1 and AuL2. The in vitro cytotoxicities of AuL1 and AuL2 determined in the NCI-60 single-dose drug screen were 56.5% and 89.1%, respectively. AuL1 was subsequently selected for a five-dose NCI-60 screen, attaining GI50, IC50, and LC50 values of 4.7, 9.3 and 39.8 μM, respectively. Hierarchical cluster analysis of the NCI-60 data indicated that the profile for AuL1 was similar to that of vinblastine sulfate, a microtubule-targeting vinca alkaloid. Reactions of AuL1 with glutathione (GSH) in vitro confirmed its susceptibility to reduction, Au(III) → Au(I), by intracellular thiols. Because human serum albumin (HSA) is responsible for transporting clinically deployed and investigational drugs, we studied the uptake of AuL1 and AuL2 by HSA to delineate how chirality impacts their protein-binding affinity. Steady-state fluorescence quenching data acquired on the native protein and data from site-specific probes showed that the compounds bind at sites close enough to Trp-214 (subdomain IIA) of HSA to quench the fluorophore. The bimolecular quenching rate constants, Kq, were ca. 102 times higher than the maximum diffusion-controlled collision constant of a biomolecule in water (1010 M−1 s−1), confirming that static fluorescence quenching was the dominant mechanism. The Stern–Volmer constants, KSV, were ∼104 M−1 at 37 °C, while the affinity constants, Ka (37 °C), measured ∼2.1 × 104 M−1 (AuL1) and ∼1.2 × 104 M−1 (AuL2) for enthalpy-driven ligand uptake targeting Sudlow's site I. Although far- and near-UV CD spectroscopy indicated that both complexes minimally perturb the secondary and tertiary structure of HSA, substantial shifts in the CD spectra were recorded for both protein-bound ligands. This study highlights the role of chirality in determining the cytotoxicity profiles and protein binding behaviour of enantiomeric Au(III) chelates. [ABSTRACT FROM AUTHOR]

Many efforts have been made in the last few decades to selectively transport antitumor agents to their potential target sites with the aim to improve efficacy and selectivity. Indeed, this aspect could greatly improve the beneficial effects of a specific anticancer agent especially in the case of orphan tumors like the triple negative breast cancer. A possible strategy relies on utilizing a protective leaving group like alizarin as the Pt(II) ligand to reduce the deactivation processes of the pharmacophore enacted by Pt resistant cancer cells. In this study a new series of neutral mixed-ligand Pt(II) complexes bearing alizarin and a variety of diamine ligands were synthesized and spectroscopically characterized by FT-IR, NMR and UV–Vis analyses. Three Pt(II) compounds, i.e., 2b, 6b and 7b, emerging as different both in terms of structural properties and cytotoxic effects (not effective, 10.49 ± 1.21 μM and 24.5 ± 1.5 μM, respectively), were chosen for a deeper investigation of the ability of alizarin to work as a selective carrier. The study comprises the in vitro cytotoxicity evaluation against triple negative breast cancer cell lines and ESI-MS interaction studies relative to the reaction of the selected Pt(II) complexes with model proteins and DNA fragments, mimicking potential biological targets. The results allow us to suggest the use of complex 6b as a prospective anticancer agent worthy of further investigations. [ABSTRACT FROM AUTHOR]

The triazolate-assisted asymmetric dinuclear oxovanadium(IV) citrate [V2O2(cit)(Hdatrz)3]·5H2O (1, H4cit = citric acid, Hdatrz = 1H-1,2,4-triazole-3,5-diamine) and its additive salt [V2O2(cit)(Hdatrz)3][V2O2(cit)2]½·2H2datrz·9.5H2O (2) and the polymerized hexanuclear product [V6O6(μ3-O)2(cit)2(Hdatrz)4]·4H2O (3) have been isolated at different temperatures, respectively. Adduct 2 shows strong evidence for the conversion of a symmetric dinuclear oxovanadium(IV) citrate to a mixed-ligand asymmetric oxovanadium(IV) citrate. Moreover, a fully oxidized trinuclear vanadium(V) species [V3O6(μ2-OH)(μ3-O)(Hdatrz)2]·4.5H2O (4) has also been isolated as a quasi-intermediate product of 3 without the coordination of citrate. Intriguingly, an octanuclear mixed-valence oxovanadium(V / IV) citrate K2{[V IV/V2 O2(cit)(Hdatrz)(datrz)]2[V IV2 O2(cit)(Hdatrz)(datrz)]2}·27.5H2O (5) has been obtained with different vanadium units, where dinuclear mixed-ligands and mixed-valence oxovanadium(IV / V) citrates [V IV/V2 O2(cit)(Hdatrz)(datrz)] (5a) and [V IV2 O2(cit)(Hdatrz)(datrz)] (5b) have been trapped. Citrate adopts a μ2-η1:η1:η1:η2 coordination mode in 1, 2 and 5, while a μ3-η1:η1:η1:η2 fashion has been observed in 3. Unlike 1–4, complex 5 contains both protonated and deprotonated triazolates simultaneously, where four triazolates further coordinate in a μ3-η1:η1:η1 manner to construct an octanuclear unit. These different structural features in 1–5 are dominated by flexible multidentate citrates and protonated/deprotonated triazolates, showing their synergistic effects. Furthermore, 1 exhibits a rectangular channel, showing preferential adsorption of O2 and CO2 over gases N2, H2, and CH4. [ABSTRACT FROM AUTHOR]

The reaction of (1R,2R)-(cyclohexane-1,2-diamine)dichloridoplatinum(II) with maleic acid unexpectedly resulted in the formation of an organometallic platinum(II) complex featuring a C,O-coordinating ligand. Additionally, a small series of close derivatives with increasing lipophilicity was synthesized. All complexes were fully characterized by multinuclear one- and two-dimensional (1H, 13C, 15N, and 195Pt) NMR spectroscopy, high resolution mass spectrometry, and in one case by X-ray diffraction. The lipophilicity and the impact on the DNA secondary structure as well as the cytotoxic properties in three human cancer cell lines (A549, SW480, and CH1/PA-1) were investigated. Unexpectedly, no clear-cut trend in cytotoxicity was observed with increasing lipophilicity. Also unexpectedly, the complexes showed only a low potential to inhibit cancer cell growth and no sign of interaction with DNA, in sharp contrast to the parent drug oxaliplatin, which seems to be caused by the low reactivity of the investigated compounds. [ABSTRACT FROM AUTHOR]

Bis(bidentate) and bis(tridentate) Co(III) complexes of N-(2-hydroxyethyl)ethane-1,2-diamine (heen), 2-[(2-aminoethyl)amino]ethan-1-olate (heen-H), or N-(2-chloroethyl)ethane-1,2-diamine (ceen) ligands have been synthesised, and a range of reaction conditions established for their syntheses by different routes. They can all be ultimately derived from (OC-6-12′)-[Co(heen)2(NO2)2]NO3 and provide access to the trans amine trans chloride nitrogen mustard complex, (OC-6-12′)-[Co(ceen)2(Cl)2]Cl. Although complex isomeric mixtures were obtained from the reaction of (OC-6-12′)-[Co(heen)2(NO2)2]NO3 under different reaction conditions, ultimately, the trans amine trans chlorido configuration around the Co(III) metal centre of the (OC-6-12′)-[Co(ceen)2(Cl)2]Cl complex was favoured. [ABSTRACT FROM AUTHOR]

Optically active C2-symmetric bis(aminophenols) based on (R)-2,2′-diaminobinaphthyl (BiniqH4) and (R,R)-2,3-butanediyldianthranilate (BdanH4) have been prepared by condensation of the diamines with 3,5-di-tert-butylcatechol. Group 10 bis(iminosemiquinone) complexes (R)-(Biniq)M (M = Pd, Pt) and (C,R,R)-(Bdan)Pd have been prepared by oxidatively metalating the corresponding ligands. In (R)-(Biniq)M, the C2 axis passes through the approximate square plane of the bis(iminosemiquinone)metal core, while in (C,R,R)-(Bdan)Pd the C2 axis is perpendicular to this plane. In the latter compound, the (R,R)-butanediyl strap binds selectively over one enantioface of the metal complex in a conformation where the methyl groups are anti to one another. Osmium oxo complexes with the intrinsically chiral OsO(amidophenoxide)2 chromophore are obtained by metalation of OsO(OCH2CH2O)2 with (R,R)-BdanH4. Both the (A,R,R) and (C,R,R) diastereomers can be observed, with metalation in refluxing toluene selectively giving the latter isomer. The electronic structures of the complexes are illuminated by the circular dichroism spectra, in conjuction with the optical spectra and TDDFT calculations. [ABSTRACT FROM AUTHOR]

The reaction of [(Me/BnTPEN)RuII(NCCH3)]2+ (BnTPEN = N1-benzyl-N1,N2,N2-tris(pyridine-2-ylmethyl)ethane-1,2-diamine and MeTPEN = N1-methyl-N1,N2,N2-tris(pyridine-2-ylmethyl)ethane-1,2-diamine) with mCPBA in the presence of chloride ions in CH3CN : H2O generated a novel (Me/BnTPEN)RuIII–OCl species at room temperature. This hypochlorite adduct could also be obtained by the direct reaction of NaOCl and HClO4 with (L)RuII complexes. The current study mimics the synthesis of a metal hypochlorite adduct in a similar fashion as in the heme-dependent haloperoxidase enzyme. As an electrophilic oxidant, the ruthenium hypochlorite adduct catalyzes hydrogen atom abstraction reactions of phenols and their derivatives. [ABSTRACT FROM AUTHOR]

The complex [PtCl2(cyclohexane-1R,2R-diamine)] has been combined in a Pt(IV) molecule with two different bioactive molecules (i.e., the histone deacetylase inhibitor 2-propylpentanoic acid or valproic acid, VPA, and the potential antimetastatic molecule 4-isopropenylcyclohexene-1-carboxylic acid or perillic acid, PA) in order to obtain a set of multiaction or multitarget antiproliferative agents. In addition to traditional thermal synthetic procedures, microwave-assisted heating was used to speed up their preparation. All Pt(IV) complexes showed antiproliferative activity on four human colon cancer cell lines (namely HCT116, HCT8, RKO and HT29) in the nanomolar range, considerably better than those of [PtCl2(cyclohexane-1R,2R-diamine)], VPA, PA, and the reference drug oxaliplatin. The synthesized complexes showed pro-apoptotic and pro-necrotic effects and the ability to induce cell cycle alterations. Moreover, the downregulation of histone deacetylase activity, leading to an increase in histone H3 and H4 levels, and the antimigratory activity, indicated by the reduction of the levels of matrix metalloproteinases MMP2 and MMP9, demonstrated the multiaction nature of the complexes, which showed biological properties similar to or better than those of VPA and PA, but at lower concentrations, probably due to the lipophilicity of the combo molecule that increases the intracellular concentration of the single components (i.e., [PtCl2(cyclohexane-1R,2R-diamine)], VPA and PA). [ABSTRACT FROM AUTHOR]

The initial use of a tetradentate Schiff base (LH2) derived from the 2 : 1 condensation between 2-hydroxyacetophenone and cyclohexane-1,2-diamine in 4f-metal chemistry is described. The 1 : 2 reaction of Ln(NO3)3·xH2O (Ln = lanthanoid or yttrium) and LH2 in MeOH/CH2Cl2 has provided access to isostructural complexes [Ln(NO3)3(L′H2)(MeOH)] in moderate to good yields. Surprisingly, the products contain the corresponding Schiff base ligand L′H2 possessing six aliphatic –CH2– groups instead of the –CH–(CH2)4–CH– unit of the cyclohexane ring, i.e. an unusual ring-opening of the latter has occurred. A mechanism for this LnIII-assisted/promoted LH2 → L′H2 transformation has been proposed assuming transient LnII species and a second LH2 molecule as the H2 source for the reduction of the cyclohexane moiety. DFT calculations provide strong evidence for the great thermodynamic stability of the products in comparison with analogous complexes containing the original intact ligand. The structures of the PrIII, SmIII, GdIII, TbIII, and HoIII complexes have been determined by single-crystal X-ray crystallography. The 9-coordinate LnIII centre in the molecules is bound to six oxygen atoms from the three bidentate chelating nitrato groups, two oxygen atoms that belong to the bidentate chelating organic ligand, and one oxygen atom from the coordinated MeOH group. In the overall neutral bis(zwitterionic) L′H2 ligand, the acidic H atoms are clearly located on the imino nitrogen atoms and this results in the formation of an unusual 16-membered chelating ring. The coordination polyhedra defined by the nine donor atoms around the 4f-metal-ion centres can be best described as distorted, spherical capped square antiprisms. The EuIII, TbIII, and DyIII complexes exhibit LnIII-based luminescence in the visible region, with the coordinated L′H2 molecule acting as the antenna. Ac magnetometry experiments show that the DyIII member of the family behaves as an SIM at zero field and under external dc fields of 0.1 and 0.2 T without the enhancement of the peaks' maxima, suggesting that QTM is not the relaxation path. The GdIII complex behaves, rather unexpectedly, as a SIM with two different magnetic relaxation paths occurring at very close temperatures; this behaviour is tentatively attributed to a very small axial zero-field splitting (D ∼ 0.1 cm−1), which cannot be detected by magnetization or susceptibility experiments. The prospects of the present, first results in the lanthanoid(III)-LH2 chemistry are discussed. [ABSTRACT FROM AUTHOR]

Considering the structural design of some of the scarce molecular-based Er-centred emitters in the literature, we explored the optical properties of three ErIII hexaazamacrocyclic complexes, namely Er-EDA (1), Er-OPDA(2) and Er-DAP(3). The macrocyclic ligands in these complexes differ in the lateral spacers, and are derived from 2,6-pyridine-dicarbaldehyde and ethylenediamine (EDA), ortho-phenylenediamine (OPDA) or 1,3-diaminopropane (DAP). Upon ligand-centred excitation, the bluish-green and green emissions of the ErIII ion were detected only for the complexes containing macrocycles with aliphatic spacers (1 and 3), which evidenced that these ligands can sensitize the ErIII luminescence. On the other hand, the ligand derived from the aromatic diamine (2) does not sensitize the ErIII luminescence. Energy transfer mechanisms, temperature sensing, CIE coordinates and CCT values were analyzed. Besides the excitation in the ligands, the erbium-centred excitation at 980 nm allowed the detection, in all cases, of bluishgreen, green and red up-converted emissions, and also the downshifted NIR emission. The possible mechanisms involved in these transitions were described and analyzed according to the available data. [ABSTRACT FROM AUTHOR]

The synthesis of a range of N-(heterocyclesulfonyl)-functionalised Noyori–Ikariya catalysts is described. The complexes were prepared through a short sequence from C2-symmetric 1,2-diphenylethylene-1,2-diamine (DPEN) and were characterised by a range of methods including X-ray crystallography. The complexes were active catalysts for the asymmetric transfer hydrogenation (ATH) of a range of acetophenone derivatives, giving products of high ee in most cases, with notably good results for ortho-substituted acetophenones. [ABSTRACT FROM AUTHOR]

Pyrazole-assisted tetranuclear microporous polyoxovanadates(III) (POVs) (NH4)2K2[V4(μ2-OH)4(ox)4(pz)4]·9H2O (1, ox = oxalate and pz = pyrazole) and (NH4)2Na2[V4(μ2-OH)4(ox)4(4-mpz)4]·7H2O (2, 4-mpz = 4-methylpyrazole) have been constructed in reduced media, along with their triazole neutral hexa- and octanuclear products K2[V6(μ2-OH)6(ox)6(Hdatrz)6]Cl2·29.5H2O (3) and [V8(μ2-OH)8(SO3)8(Hdatrz)8]·38H2O (4, Hdatrz = 1H-1,2,4-triazole-3,5-diamine) successively. Both polyanionic structures of 1 and 2 share similar inorganic building blocks that consist of regular {V4(μ2-OH)4} skeletons with an inner diameter of 2.8 Å, while a paddle wheel-shaped cluster 3 contains a {V6(μ2-OH)6} skeleton with two chlorides encapsulated around the center of the ring, occupying a hole of 3.7 Å. An interesting isolated intrinsic polyoxometalate-based metal–organic framework (POMOF) 4 exists as an octanuclear petaloid-like skeleton {V8(μ2-OH)8(SO3)8} with an inner diameter of 5.2 Å. Bond valence sum calculations manifest that all V ions have severely reduced +3 oxidation states in 1–4, which are supported by charge balance, structural and magnetic data. Moreover, gas adsorptions indicate that 1, 2 and 4 can adsorb CO2 and O2 more favorably than N2, CH4 and H2 gases. Compared with 1 and 2, due to the functionalization of microchannels with Lewis base amino and hydroxy groups and uncoordinated azolate N-donors inside POMOF 4, it should have notable affinities toward CO2 adsorption. [ABSTRACT FROM AUTHOR]

Molybdenum complexes ligated with N1,N1-dialkyl-N2-(5,6,7,8-tetrahydroquinolin-8-yl)ethane-1,2-diamines and auxiliary ligands, providing various structural features, were developed: [NNH/NNHN]Mo(CO)4/3 (Mo1–Mo3), [NNHN]Mo(CO)2Br (Mo4–Mo5), [NNH]Mo(CO)(η3-C3H5)Br (Mo6) and [NNHN/S]Mo(CO)(PPh3)2 (Mo7–Mo8). All the complexes were highly active in the transfer hydrogenation (TH) of a model substrate (acetophenone), providing excellent yields of 1-phenylethanol. The structural variation in the ligand framework had a modest effect on the catalyst performance as compared to the changes in the auxiliary ligands Br, PPh3 and CO. This structural evolution provided the complex [Mo(NNH)(η3-C3H5)(CO)2Br] (Mo6) as the most effective catalyst not only for the transfer hydrogenation of acetophenone but also for a wide range of diverse ketones (up to 43 examples). Moreover, easy purification of the products by only removing the acetone byproduct is another noteworthy feature of this environmentally friendly route. [ABSTRACT FROM AUTHOR]

The novel dimeric iodo-iridium(III) complex, [Ir(Cp*CONMe2)I2]2, (Cp*CONMe2 = η5-N,N-2,3,4,5-hexamethylcyclopenta-2,4-diene carboxamide) bearing an amide moiety within the tetramethylcyclopentadiene ring, has been synthesised and characterised. The ligand Cp*CONMe2 is synthesised as two regioisomers, however the 2-substituted isomer exists as two distinguishable conformers due to restricted rotation about the amide carbonyl carbon and the ring carbon. The relative acidities of Cp*CONMe2 and Cp* are compared by their relative rates of H/D exchange. The iridium complex of N,N-2,3,4,5-hexamethylcyclopenta-2-4-diene carboxamide [IrCp*CONMe2] and (R,R)-1,2-diphenyl-N′-tosylethane-1,2-diamine ((R,R)-TsDPEN) has been evaluated in the transfer hydrogenation of imines under acidic conditions – a 5 : 2 molar ratio of formic acid : triethylamine as the hydride source for the transfer hydrogenation of 1-methyl-3,4-dihydroisoquinoline (DHIQ) and its 6,7-dimethoxy derivative in acetonitrile. A decreasing enantiomeric excess with reaction progress is attributed to different kinetic orders for formation of the two product amine enantiomers. The pseudo zero-order formation of the R-amine may be due to a pre-steady-state formation of the less stable form of the diastereomeric catalyst. By contrast, both enantiomeric amines from 1-fluorinated methyl DHIQs as substrates for reduction are formed by pseudo first-order processes. [ABSTRACT FROM AUTHOR]

Hybrid materials composed of organic and inorganic components offer the opportunity to develop interesting materials with well-controlled properties. Molecular Layer Deposition (MLD) is a suitable thin film deposition technique for the controlled growth of thin, conformal hybrid films. Despite the great interest in these materials, a detailed understanding of the atomistic mechanism of MLD film growth is still lacking. This paper presents a first principles investigation of the detailed mechanism of the growth of hybrid organic–inorganic thin films of aluminium oxide and aromatic molecules with different terminal groups deposited by MLD. We investigate the chemistry of the MLD process between the post-TMA pulse methyl-terminated Al2O3 surface and the homo- or hetero-bifunctional aromatic compounds with hydroxy (OH) and/or amino (NH2) terminal groups: hydroquinone (HQ), p-phenylenediamine (PD) and 4-aminophenol (AP). Double reactions of aromatic molecules with the alumina surface are also explored. We show that all aromatic precursor molecules bind favourably to the methyl terminated Al2O3, via formation of Al–O and Al–N bonds and CH4 elimination. While reaction energetics suggest a higher reactivity of the OH group with TMA in comparison to the NH2 group, which could enable the double reaction phenomenon for HQ, we propose that the upright configuration will be present so that the organic molecules are self-assembled in an upright configuration, which leads to thicker hybrid films. Interactions between the methyl-terminated Al2O3 with substituted phenyls are investigated to examine the influence of phenyl functionalisation on the chemistry of the terminal groups. Reaction energetics show that phenyl functionalization actually promotes an upright configuration of the molecule, which leads to thicker and more flexible films, as well as tuning the properties of the aromatic components of the hybrid films. We also investigate the interactions between methyl-terminated Al2O3 with new possible MLD organic precursors, hydroquinone bis(2-hydroxyethyl)ether and 1,1′-biphenyl-4,4′-diamine. DFT shows that both aromatic molecules react favourably with TMA and are worthy of further experimental investigation. [ABSTRACT FROM AUTHOR]

Sustainable electrocatalytic water splitting stipulates the development of cheap, efficient and stable electrocatalysts to promote comparatively sluggish oxygen evolution reaction. We have synthesized iron-incorporated pure phase α-nickel hydroxide, Ni0.8Fe0.2(OH)2 electrocatalyst utilizing N,N,N′,N′-Tetramethylethane-1,2-diamine (TMEDA) and ethylene glycol (EG) following a simple one-pot synthesis process. PXRD and FTIR data suggest that the intercalation of EG in the interlayer spacing promotes amorphousness of the material. FESEM and TEM analyses suggest that the catalyst possesses hierarchical sheet-like morphology and BET measurements indicated the surface area of 50 m2 g−1 with high mesoporosity. Electrochemical studies suggest that Ni0.8Fe0.2(OH)2 prepared using water–EG mixture is the most efficient electrocatalyst for OER activity as it requires only 258 mV overpotential (considering backward LSV) on a glassy carbon electrode to achieve the benchmark current density of 10 mA cm−2geo. Additionally, the catalyst shows remarkable long-term stability for up to 7 days. The efficiency of Ni0.8Fe0.2(OH)2 electrocatalyst is reflected in its low Tafel slope (43 mV dec−1) and high OER faradaic efficiency (93%). The enhanced activity is attributed to the increase in the interlayer spacing due to the intercalation of EG into the material, which facilitates the transport of ions during the OER process. The overall improved catalytic property is due to the enhanced ionic mobility, controllable textural property, higher per-site activity and increased conductivity for the Ni0.8Fe0.2(OH)2 catalytic network. [ABSTRACT FROM AUTHOR]

We describe the synthesis of N-functionalised phosphinecarboxamides obtained by reaction of the 2-phosphaethynolate anion (PCO−) with diamines, specifically hydrazine, methylenediamine and ethylenediamine, in the presence of acid. The resulting neutral compounds can be deprotonated to generate phosphide anions that, when further reacted with electrophiles, form secondary phosphines. [ABSTRACT FROM AUTHOR]

The Pt(IV) complexes based on (SP-4-2)-dichlorido(cyclohexane-1,4-diamine)platinum(II) (kiteplatin) and the histone deacetylase inhibitor 2-(2-propynyl)octanoic acid (POA) were investigated. Since POA contains a chiral carbon, all the possible Pt(IV) isomers were prepared and characterized, and their antiproliferative activity on six cancer cell lines was compared with that of the corresponding Pt(IV) complexes containing the cyclohexane-1R,2R-diamine equatorial ligand. To justify the very good antiproliferative activity (nanomolar IC50), the polarity, lipophilicity, permeability, and cell accumulation of the complexes were studied. Overall, the two series of Pt(IV) complexes showed similar cell penetration properties, being significantly better than that of the Pt(II) reference compounds. Finally, a representative compound of the whole set of complexes (i.e., that based on cyclohexane-1R,2R-diamine and racemic POA) was tested in vivo on mice bearing Lewis lung carcinoma, showing good tumor growth inhibition with negligible body weight loss. [ABSTRACT FROM AUTHOR]

Through the high dilution technique, we obtained macrocyclic ion pair receptors R1 and R2, an anion receptor R3, and a fluorescent sensor R4 using a combination of particular members of simple libraries consisting of synthesized diamines and methyl squarates, respectively. The receptors were investigated in terms of anion and ion pair binding using the 1H NMR titration method in DMSO-d6. We found that the major contribution to the anion binding comes from the interaction with the squaramide protons rather than with the amide functions of the receptors. The receptors demonstrated the highest affinity towards benzoates and sulfates over the anions tested, and in the case of sulfate binding more complex equilibria in solution were observed. Unlike the anion receptor R3, the ion pair receptor R1 was found to recognize anions in an enhanced manner with the assistance of sodium or potassium cations. Tethering of a simple fluorophore in close proximity to the amide function of receptor R4 resulted in an optical ion pair sensor selective towards sulfates. DFT calculations carried out for the 1 : 1 complexes of R3 with the anions helped clarify this selectivity, showing more effective participation of tetrahedral sulfate anions in binding with the amide function than in the case of benzoates or chlorides. [ABSTRACT FROM AUTHOR]

A mononuclear manganese(III)–peroxo complex [MnIII(N3Py2)(O2)]+ (1a) bearing a non-heme N,N′-dimethyl-N-(2-(methyl(pyridin-2-ylmethyl)amino)ethyl)-N′-(pyridin-2-ylmethyl)ethane-1,2-diamine (N3Py2) ligand was synthesized by the reaction of [Mn(N3Py2)(H2O)](ClO4)2 (1) with hydrogen peroxide and triethylamine in CH3CN at 25 °C. The reactivity of 1a in aldehyde deformylation using 2-phenyl propionaldehyde (2-PPA) was studied and the reaction kinetics was monitored by UV-visible spectroscopy. A kinetic isotope effect (KIE) = 1.7 was obtained in the reaction of 1a with 2-PPA and α-[D1]-PPA, suggesting nucleophilic character of 1a. The activation parameters ΔH‡ and ΔS‡ were determined using the Eyring plot while Ea was obtained from the Arrhenius equation by performing the reaction between 288 and 303 K. Hammett constants (σp) of para-substituted benzaldehydes p-X-Ph-CHO (X = Cl, F, H, and Me) were linear with a slope (ρ) = 3.0. Computational study suggested that the side-on structure of 1a is more favored over the end-on structure and facilitates the reactivity of 1a. [ABSTRACT FROM AUTHOR]

Supramolecular chirogenesis is one of the most rudimentary topics in the interdisciplinary sciences and essentially deals with various natural processes and innovative modern technologies. A comprehensive and rigorous understanding of such phenomenon is necessary to have a clear insight into the fundamental mechanisms and the various controlling factors, which would eventually lead to a range of practical applications of chiral supramolecular science. Metalloporphyrin tweezers have been extensively employed for such chirogenic processes due to their exciting physicochemical and tunable spectral properties, large stabilities, easily available synthetic protocols, and excellent abilities to form molecular assemblies. During the last few decades, various metalloporphyrin tweezers have been developed and considerably utilized by several research groups for assigning the absolute configuration to a variety of chiral diamines, conjugates of primary and secondary amines, amino alcohols, secondary alcohols, α-chiral carboxylic acids, etc. Our group has been at the forefront in trying to establish the structure–property correlation in this important area of interdisciplinary research. A brief account of our systematic investigation for understanding the underpinning mechanism of chirality induction and control at the molecular level over the last few years is presented in this Perspective article. The comprehensive understanding of such mechanistic details will be helpful in understanding various natural processes and designing modern technologies for various chirogenic functions in the fields of molecular sensors, nanotechnology, and supramolecular chemistry. [ABSTRACT FROM AUTHOR]

We show that the azamacrocycle 'cyclam' (1,4,8,11-tetraazacyclodecane) in conjunction with a silicon catecholate ion generates novel hollow tetragonal tube-like crystalline materials [(C6H4O2)3Si][C10H26N4]·H2O, whose dimensions can be tuned according to the pH of the reaction medium. The synthesis approach was successful for both silicon and germanium and we hypothesise that a range of other catecholate precursors of elements such as iron could be used to generate a large array of inorganic materials with interesting morphologies. The synthesis approach can be extended to tertiary diamines with functional group spacing playing an important role in the efficacy of complexation. Of the molecules explored to date, a C2 spacing (N,N,N′,N′-tetramethylethylenediamine (4MEDAE)), leads to the most efficient structure control with hollow hexagonal tube-like structures being formed. In addition, we show that azamacrocycles, in the presence of unbuffered tetramethoxysilane (TMOS) solutions can be used to manipulate silica formation and provide a fast (ca. 10 minutes) synthesis route to particles whose diameter can be tuned from ca. 20 nm to several hundreds of nm under reaction conditions (no extremes of pH) that make the sols suitable for direct use in biotechnological applications. [ABSTRACT FROM AUTHOR]

Three pairs of asymmetric dicarboxylato derivatives based on the cisplatin and oxaliplatin-like skeletons have been synthesized de novo or re-synthesized. The axial ligands consist of one medium-chain fatty acid (MCFA), namely clofibrate (i.e. 2-(p-chlorophenoxy)-2-methylpropionic acid, CA), heptanoate (HA) or octanoate (OA), respectively, and an inactive acetato ligand that imparts acceptable water solubility to such conjugates. Stability tests provided evidence for the partial formation of two hydrolyzed products, corresponding to two monoaqua diastereomers derived from the substitution of an equatorial chlorido ligand with a water molecule. The complexes have been tested on three different colon cancer cell lines having different histological history, and also on the cisplatin-sensitive A2780 ovarian cancer cell line for comparison. This allowed the evaluation not only of the increase in activity on passing from Pt(ii) to Pt(iv) derivatives, but also the selectivity towards colon cancer cells brought about by the cyclohexane-1R,2R-diamine carrier ligand. [ABSTRACT FROM AUTHOR]

A highly crystalline new precursor of CHA-type zeolite AlPO4-34 was obtained by using an aluminophosphate gel with a chiral diamine [(S)-(+)-1-(2-pyrrolidinylmethyl)pyrrolidine; C9H18N2] as an organic structure directing agent under hydrothermal synthesis conditions. This precursor (called GAM-1) was changed into the zeolite AlPO4-34 which had a high porosity (the Brunauer–Emmett–Teller (BET) surface area is approximately 700 m3 g−1) using calcination. The GAM-1 obtained was characterized by various measurements, e.g., powder X-ray diffraction, scanning electron microscopy, and solid-state nuclear magnetic resonance spectroscopy, and so on. Structure determination from powder diffraction data revealed that the new precursor GAM-1 has triclinic symmetry [space group P1̅, a = 9.16535(11) Å, b = 9.23042(11) Å, c = 9.29228(11) Å, α = 79.8243(7)°, β = 87.4593(7)°, γ = 86.5365(7)°] and the chemical formula was estimated to be: ☋Al6P6O24H2F2☋(C9H18N2)·2.5(H2O). It also revealed that a two edge sharing AlO4F2 octahedron with an ≡Al–F–Al≡ bridge was included in the framework. GAM-1 was transformed into AlPO4-34 with rhombohedral symmetry (R3̅) by elevating temperature to over 400 °C. At high temperatures, AlO4F2 octahedron connectivity was changed into an AlO4 tetrahedron. The crystal structure of the dehydrated AlPO4-34 changed back to a triclinic symmetry (P1) model again after rehydration in the atmosphere. [ABSTRACT FROM AUTHOR]

Biodegradable, PEG-coated, nanoparticles (NPs) have gained therapeutic application as injectable colloidal systems for the controlled and site-specific release of drugs. In this paper, encapsulation in PLGA-PEG polymer NPs has been exploited to lower the toxicity and to increase the antitumor activity of kiteplatin ([PtCl2(cis-1,4-DACH)]). Kiteplatin contains an isomeric form of the diamine ligand present in oxaliplatin and proved to be particularly active against ovarian and colon cancers. To favor encapsulation of the platinum drug in the hydrophobic core of the polymeric micelles, Pt(iv) prodrugs having hydrophobic carboxylic ligands at the axial positions were used in place of hydrophilic Pt(ii) complexes (compounds 1–4). The size, size distribution, and zeta potential (ZP) were measured by dynamic light scattering (DLS) and laser Doppler velocimetry (LDV), and drug encapsulation efficiency (EE) correlated to the alkyl chain length of the different Pt(iv) prodrugs. The number of the Pt atoms per NP (in the range of 1.3–2.4 × 106) is comparable to that of polysilsesquioxane-based NPs and higher than that found for other nanoparticle platforms. The platinum-loaded PLGA-PEG NPs, tested in vivo in a syngeneic murine solid tumor (LLC), had a higher antitumor effect and, most importantly, were markedly less toxic than kiteplatin. [ABSTRACT FROM AUTHOR]

A fluorenyl (Fl) tethered diamine was synthesised by nucleophilic substitution of (bromoethyl)fluorene with a diisopropylphenyl (Dipp) substituted diamine to give FlC2H4N(H)C2H4N(H)Dipp (1a) in good yield (85%). Lithiation of 1a with n-BuLi proceeded with coordination of the Li cation to the aromatic fluorenide ring (2), and with subsequent equivalents of n-BuLi, the secondary amines were then sequentially deprotonated. A fluorenyl-tethered N-heterocyclic stannylene (NHSn) was synthesised from the reaction of 1a with SnN′′2 {N′′ = N(SiMe3)2} as a neutral dimeric species (5), and this was deprotonated with LiN′′ to give the corresponding dianionic fluorenide-tethered NHSn (6). Reactions of [{Rh(cod)(μ-Cl)}2] with the mono-deprotonated ligand 2 led to the formation of a mixed-donor amide–amine Rh(i) compound (7), whereas reactions with the anionic NHSn 6 led to a Rh–fluorenyl complex of low stability with an uncoordinated pendent NHSn arm, which X-ray crystallography showed to be dimeric in the solid state. [ABSTRACT FROM AUTHOR]

A novel macrocyclic DO3A derivative containing a linear diamine pendant arm, H3do3aNN, was prepared and its protonation and complexation properties were studied by means of potentiometry. It determined ligand consecutive protonation constants log KAn = 12.62, 10.28, 9.67, 8.30, 3.30 and 1.58 and stability constants of selected lanthanide (Eu(iii), Yb(iii)) complexes log KEuL = 23.16 and log KYbL = 22.76. The complexes could be protonated on the pendant amino group(s) with log K(HLM) ≈ 5.6 and log K(H2LM) ≈ 4.8. Solution structures of both complexes were studied by NMR spectroscopy. The study revealed that the complex species exist exclusively in the form of twisted-square-antiprismatic (TSA) isomers. The complexes show significant pH dependence of the Chemical Exchange Saturation Transfer (CEST) between their amino groups and the bulk water molecules in the pH range of 5–8. Thus, the pH dependence of the magnetization transfer ratio of CEST signals can be used for pH determination using magnetic resonance imaging techniques in a pH range relevant for in vivo conditions. [ABSTRACT FROM AUTHOR]

Salen-type mononuclear lanthanide complexes with formula (Et3NH)[Ln(3-NO2-salen)2]·solvent (Ln = Eu (1Eu), Tb (2Tb), Dy (3Dy), Ho (4Ho), Er (5Er), Yb (6Yb); 3-NO2-salen2− = N,N′-bis(3-nitro-salicylaldehyde)ethylenediamine dianion) are reported. These compounds are isostructural in which two crystallographically distinct 3-NO2-salen2− act as tetradentate ligands encapsulating the lanthanide ions in a meridional mode forming the [LnN4O4] cores. Slow magnetization relaxation processes associated with single ion magnet (SIM) behaviors are observed in complexes 3Dy, 5Er and 6Yb with the Kramer ions but not in 2Tb and 4Ho with non-Kramer ions. Photoluminescence studies reveal that complexes 1Eu, 5Er and 6Yb exhibit characteristic lanthanide luminescence with sharp and well-separated emission bands. Complex 1Eu is of particular interest in which the organic ligand functioning as a powerful absorbing sensitizer apparently broadens the excitation range into 300–500 nm with the maximum of 460 nm. [ABSTRACT FROM AUTHOR]

A novel synthetic approach toward a poorly explored bioorganometallic consisting of ferrocene-1,1′-diamine bearing structurally and chirally diverse amino acid sequences is reported. Until now, ferrocene-1,1′-diamine was suitable for accommodating only identical amino acid sequences at its N-termini, leading to the symmetrically disubstituted homochiral products stabilized through a 14-membered intramolecular hydrogen-bonded ring as is seen in antiparallel β-sheet peptides. The key step of the novel synthetic pathway is the transformation of Ac–Ala–UGRAPHIC DISPLAY="INLINE" ID="UGR5" SRC="UGR5"/–Fn–UGRAPHIC DISPLAY="INLINE" ID="UGR6" SRC="UGR6"/OH (5) (Fn = 1,1′-ferrocenylene) to orthogonally protected Ac–Ala–UGRAPHIC DISPLAY="INLINE" ID="UGR7" SRC="UGR7"/–Fn–UGRAPHIC DISPLAY="INLINE" ID="UGR8" SRC="UGR8"/Boc (7). The spectroscopic analysis (IR, NMR, CD) of the novel compounds, corroborated with DFT studies, suggests the interesting feature of the ferrocene-1,1′-diamine scaffold. The same hydrogen-bonding pattern, i.e. a 14-membered hydrogen-bonded ring, was determined both in solution and in the solid state, thus making them promising, yet simple scaffolds capable of mimicking β-sheet peptides. In vitro screening of potential anticancer activity in Hep G2 human liver carcinoma cells and Hs 578 T human breast cancer cells revealed a cytotoxic pattern for novel compounds (150–500 μM) with significantly decreased cell proliferation. [ABSTRACT FROM AUTHOR]

New unsymmetrical binuclear nickel(ii) complexes [Ni2L1–5] (ClO4)2 (1–5) were synthesized by using [NiL] [(3-((9E)-(2-((E)-(3-formyl-2-olato-5-methylbenzylideneamino)methyl) phenylimino)methyl)-3-formyl-5-methyl-2-olato)nickel(ii)] with various diamines like 1,2-diaminoethane (L1), 1,3-diaminopropane (L2), 1,4-diaminobutane (L3), 1,2-diaminobenzene (L4) and 1,8-diaminonaphthalene (L5) and characterized by elemental analysis and spectroscopic methods. The molecular structure of binuclear nickel(ii) complex 1 is determined by a single crystal X-ray diffraction method. Cyclic voltammograms of binuclear Ni(ii) complexes exhibit two quasi-reversible reduction waves in the cathodic region and two oxidation waves in the anodic region. DNA binding, protein binding and DNA cleavage studies were investigated. The interactions of complexes (1–5) with calf thymus DNA were studied by spectroscopic techniques, including absorption and fluorescence methods. The binding affinities of complexes (1–5) with CT-DNA and nuclease activities are in the following order: 5 ＞ 4 ＞ 3 ＞ 2＞1. Binuclear Ni(ii) complex 1 cleaved the plasmid DNA by a hydrolytic pathway. The hydrolytic cleavage of DNA by the complexes is supported by evidence from free radical quenching and T4 ligase ligation. Binuclear Ni(ii) complexes (1–5) displayed significant protein (bovine serum albumin) interactions. The experimental results showed that the interaction between binuclear Ni(ii) complexes and BSA was mainly a static quenching process. [ABSTRACT FROM AUTHOR]

A novel polydentate Schiff base ligand N1,N3-bis[(6-methoxypyridin-2-yl)methylene]benzene-1,3-diamine (L) and its two dinuclear sandwich-like complexes {[CdL(NO3)(H2O)]·NO3}2 (1) and {[CdL(CH3CN)(H2O)]·(ClO4)2·(CH3CN)2}2 (2) were synthesized. Both C–H…O, C–H…N and π–π non-covalent interactions had essential roles in constructing the resulting three-dimensional supramolecular networks. L emits a more intense blue-green fluorescence emission around 493 nm than in dilute solution, exhibiting stacking-induced emission properties. Complexes 1 and 2 exhibited the dual properties of exceptional solvatochromism and fluorescence quenching towards CH3OH molecules. As these compounds could overcome the absent absorption of ruthenium complex N719 in the low wavelength region of the visible spectrum, offset the competitive visible light absorption of I3− and reduce the charge recombination of injected electrons, the Schiff base ligand L and complexes 1 and 2 were used as co-sensitizers in combination with N719 to investigate their effect on enhancing the performance of dye-sensitized solar cells. A short circuit current density of 14.37 mA cm−2, an open-circuit voltage of 0.71 V and a fill factor of 0.61 corresponding to an overall conversion efficiency of 6.17% under AM 1.5 G solar irradiation were achieved when 1 was used as a co-sensitizer, which are much higher than the results obtained for dye-sensitized solar cells sensitized by N719 alone (5.06%). [ABSTRACT FROM AUTHOR]

Reaction of LiAlH4 with 1,2-phenylenediamine (1H4) in THF results in formation of the metallocyclic amido-/imido complex [{Al(1H2)}2{Al(1H)2}2][Li(THF)2]4 (3), while in the presence of various Lewis base ligands 1,8-diaminonaphthalene (2H4) gives the amido-(‘ate’) complexes [Al(2H2)2]−[Li(LL′)]+ [L = THF, L′ = PMDETA (N,N,N′,N′,N′′-pentamethyldiethylenetriamine) (4); L = L′ = TMEDA (N,N,N′,N′-tetramethylethylenediamine) (5)]. The latter complexes provide evidence of intermediates in the proposed reaction pathway for formation of the cyclic framework of the tetraanion [{Al(1H2)}2{Al(1H)2}2]4− of 3. [ABSTRACT FROM AUTHOR]

Four isomorphic tetranuclear lanthanide complexes, namely [Ln4(L)2(HL)2(NO3)2(OH)2](NO3)2·4H2O (Ln = Dy (1); Tb (2); Ho (3); Er (4)), constructed using hexadentate salen-type ligand N,N′-bis(3-methoxy-salicylidene)cyclohexane-1,2-diamine, have been isolated. X-ray crystallographic analysis reveals that all of the complexes 1–4 are of discrete tetranuclear structure with a unique {Ln4O8} core in which four lanthanide ions are coplanar in a rhombic frame. There are two crystallographically unequivalent lanthanide ions, that is the Ln1III ion which is nine-coordinated in a monocapped square-antiprismatic geometry of the C4v point group and the Ln2III ion which is eight-coordinated in a distorted bicapped trigonal-prismatic geometry of the C2v point group. Magnetic analysis reveals that complex 1 exhibits two slow magnetic relaxations with the highest energy barrier among the reported tetranuclear salen-type dysprosium SMMs. This further extends the available SMMs of salen-type lanthanide complexes. [ABSTRACT FROM AUTHOR]

Reaction of LiAlH4 with 1,2-phenylenediamine (1H4) in THF results in formation of the metallocyclic amido-/imido complex [{Al(1H2)}2{Al(1H)2}2][Li(THF)2]4 (3), while in the presence of various Lewis base ligands 1,8-diaminonaphthalene (2H4) gives the amido-(‘ate’) complexes [Al(2H2)2]−[Li(LL′)]+ [L = THF, L′ = PMDETA (N,N,N′,N′,N′′-pentamethyldiethylenetriamine) (4); L = L′ = TMEDA (N,N,N′,N′-tetramethylethylenediamine) (5)]. The latter complexes provide evidence of intermediates in the proposed reaction pathway for formation of the cyclic framework of the tetraanion [{Al(1H2)}2{Al(1H)2}2]4− of 3. [ABSTRACT FROM AUTHOR]

The reactivity, cytotoxic studies and hydrolytic behaviour of diamine bis(phenolate) titanium complexes are reported. The reactions of [Ti(tBu2O2NN')Cl]2(μ-O) (1) with LiOiPr or HOiPr in the presence of NEt3, aiming at the synthesis of the alkoxido derivative of 1 led to no reaction or to the synthesis of the monomeric complex [Ti(tBu2O2NN')(OiPr)2] (3), respectively. A small amount of the alkoxidotitanium dimer [Ti-(tBu2O2NN')(OiPr)]2(μ-O) (2) crystallized out of a solution of 3 and DFT calculations showed that the transformation of 1 into 3 is a thermodynamically favorable process in the presence of a base (NEt3) (∆G = -14.7 kcal mol-1). 2 was quantitatively obtained through the direct reaction of the ligand precursor H2(tBu2O2NN') with titanium tetra(isopropoxido). Further reaction of 2 with an excess of TMSCl was revealed to be the most suitable method for the preparation of [Ti(tBu2O2NN')Cl2] (4). 1 and 3 disclosed cytotoxic activity towards HeLa, Fem-x, MDA-MB-361 and K562 cells and 1 exhibited moderate binding affinity to FS-DNA. ¹H NMR hydrolysis studies attested the fast decomposition of 4 in the presence of D2O. The hydrolysis of 3 is slower and proceeds through the formation of [Ti(tBu2O2NN')(OH)]2(μ-O) (5) that was crystallographically characterized. Upon D2O addition 1 immediately forms complex new species, stable in solution for long periods (weeks). [ABSTRACT FROM AUTHOR]

The Cu(II) complex 1, Cu(II)-6-N-3,5-di-tert-butylsalicylidene-6,7-quinoxalinol-diamine, has been developed to address problems with current methods of catalytic oxidation using tert-butyl hydroperoxide (TBHP). Complex 1 demonstrated an increased capability to utilize TBHP while limiting interference from free radical reactions and was demonstrated to be highly effective in the oxidations of a variety of olefins. [ABSTRACT FROM AUTHOR]

Directed by diprotonated organic diamines containing both primary and tertiary ammonium groups, three layered iodoplumbate hybrids, {[H2DMPDA][PbI4]}n (1), {[H2DEPDA]4[Pb5I18]}n (2) and {[H2TMEDA][Pb3I8]}n (3) (DMPDA = N,N-dimethyl-1,3-propanediamine, DEPDA = N,N-diethyl-1,3-propanediamine, TMEDA = N,N,N',N'-tetramethylethylenediamine), have been synthesized solvothermally. 1 presents a layered perovskite structure based on corner-sharing PbI6 octahedra, compound 2 consists of a Pb4I20 perovskite motif and a Pb2I10 dimeric motif and compound 3 comprises Pb3I13 units connected by face-sharing and edge-sharing modes. Structural modulations from nonperovskite to perovskite structure are strongly correlated to steric effects and hydrogen bonding interaction at the organic-inorganic interface. Band gaps for 1-3, estimated as 2.21, 2.58 and 2.73 eV, respectively, also reveal an interesting correlation with structural modulation, and the red shift for 1 is attributed to large Pb-Iequatorial-Pb bond angles. [ABSTRACT FROM AUTHOR]

Three chloride-bridged lanthanide compounds, [Ln4Cl6(CH3OH)12(OH)2]·4Cl·2CH3OH [Ln = Gd (1), Dy (2) and Er (3)], have been unexpectedly isolated by the reactions of LnCl3·6H2O and N,N′-bis(salicylidene)- 1,2-(phenylene-diamine) (H2L). X-ray crystallographic analysis reveals a triclinic cell with a unique defectdicubane {Ln4} core and the structure across this series is nominally isomorphic. Measurements of direct current magnetic susceptibility and isothermal magnetization give insight into the relevant cluster Hamiltonians for 1, 2, and 3, and alternating current susceptibility shows slow relaxation in 2, but not in 1 or 3 down to 2 K and up to 1 kHz. [ABSTRACT FROM AUTHOR]

SBA-15 functionalized with N-[3-(trimethoxysilyl)propyl]ethylene-diamine (TPED) was synthesized and used for the colorimetric detection of Cu2+ and removal of heavy metal ions in aqueous solutions. Compared to free SBA-15, the adsorption ability of diamine-functionalized SBA-15 (depicted as SBA-TPED) increased remarkably, the maximum adsorption capacity of SBA-TPED for Cu2+, Pb2+ and Zn2+ was 27.22, 96.43 and 12.16 mg g-1, respectively. Furthermore, SBA-TPED exhibits high selectivity for Cu2+ with the relative selectivity coefficient of SBA-TPED for Cu2+/Pb2+ being over 10 and for Cu2+/Zn2+ being over 60. The naked-eye detection limit of SBA-TPED for Cu2+ is 0.95 ppm, and the determination of Cu2+ in real water samples also displays satisfactory results. Moreover, SBA-TPED possesses fast kinetics for removing Cu2+ with a saturation time of less than 30 min, and can be regenerated by simple acid treatment. [ABSTRACT FROM AUTHOR]

With transition metal complexes as the structure-directing agents, two novel aluminoborates with a 2D layer [Cu(enMe)2]3{Al2[B5O8(OH)2]4}.H2O (1, enMe = 1,2-diaminopropane) and a 3D open-framework [Cu(en)2][Al-B5O10] (2, en = ethylenediamine) have been solvothermally prepared and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, UV/Vis spectroscopy, powder and singlecrystal X-ray diffraction. 1 is a 2D {Al[B5O8(OH)2]2}3- layer constructed by the alternate linkages of AlO4 groups and B5O8(OH)2 clusters. The 2D layer contains 16-member rings (MRs), showing a unique sql net topology. In 2, the AlO4 groups and B5O10 clusters alternately link together to form a 3D framework, in which the stacking of building layers is different. The copper centres are chelated by two amine ligands to form a square planar, which have weak axial interactions with the aluminoborate frameworks. [ABSTRACT FROM AUTHOR]

Presented here are three organic-decorated manganese selenidostannates with various structural dimensionalities (D), namely, 1D – SnSe3Mn(en)2 (en = ethylenediamine) (1), 2D – SnSe3Mn(en) (2) and 3D – MnSnSe4Mn(en)2 (3). 2 and 3 represent the first 2D and 3D organic-decorated Mn–Sn–Se compounds, respectively. A structural transformation was observed between 1 and 2. [ABSTRACT FROM AUTHOR]

Treatment of the ortho-phenylene diamine C6H4-1,2-{N(H)Tripp}2 (1, PDAH2, Tripp = 2,4,6-triisopropylphenyl) with two equivalents of MR (M = Li, R = Bun; M = Na or K, R = CH2C6H5) afforded the dimetallated alkali metal ortho-phenylene diamide dianion complexes [(PDALi2)(THF)3] (2), [{(PDANa2)(THF)2}2] (3), and [{(PDAK2)(THF)3}2] (4). In contrast, treatment of 2 with two equivalents of rubidium or cesium 2-ethylhexoxide, or treatment of 1 with two equivalents of MR (M = Rb or Cs, R = CH2C6H5) did not afford the anticipated dialkali metal ortho-phenylene diamide dianion derivatives and instead formally afforded the monometallic ortho-diiminosemiquinonate radical anion species [PDAM] (M = Rb, 5; M = Cs, 6). The structure of 2 is monomeric with one lithium coordinated to the two nitrogen centres and the other lithium η4-coordinated to the diazabutadiene portion of the PDA scaffold. Similar structural cores are observed for 3 and 4, except that the larger sodium and potassium ions give dimeric structures linked by multi-hapto interactions from the PDA backbone phenyl ring to an alkali metal centre. Complex 5 was not characterised in the solid state, but the structure of 6 reveals coordination of cesium ions to both PDA amide centres and multi-hapto interactions to a PDA backbone phenyl ring in the next unit to generate a one-dimensional polymer. Complexes 2-6 have been variously characterised by X-ray crystallography, multi-nuclear NMR, FTIR, and EPR spectroscopies, and CHN microanalyses. [ABSTRACT FROM AUTHOR]

Novel diamino and azamacrocycle functionalized porphyrins were efficiently synthesized by palladiumcatalyzed amination of mono- and bis(meso-(bromophenyl))porphyrins. The optimization of reaction conditions allowed us to achieve high yields of products with substrates of different types. Supramolecular utility of the thus obtained aminoporphyrins was shown by investigations of processes of coordination self-assembly in solution by NMR and UV-Vis spectroscopy. The crystalline 1D-coordination polymer formed via self-assembly of N,N-dimethylethylenediamine substituted zinc porphyrin was characterized by X-ray diffraction. [ABSTRACT FROM AUTHOR]

A series of 1,3-bis(perfluoroaryl)-2-(hetero)aryl-1,3,2-benzodiazaboroles, 1,3-FAr2-2-Ar-1,3,2-N2BC6H4 (Ar = Ph, FAr = C6F5 5; Ar = Ph, FAr = 4-C5F4N 6; Ar = Ph, FAr = 4-NCC6F4 7; Ar = 2-C4H3S, FAr = C6F5 8; Ar = 2-C4H3S, FAr = 4-C5F4N 9; Ar = 2-C4H3S, FAr = 4-NCC6F4 10), were synthesised by cyclocondensation of the adducts PhBBr2.PPh3 or 2-thienylBBr2.PPh3 with N,N'-bis(perfluoroaryl)-o-phenylenediamines in the presence of 2,2,6,6-tetramethylpiperidine. Similar treatments of the PPh3 adducts of 4-(1',3'- diethyl-1',3',2'-benzodiazaborolyl)-phenyldibromoborane with the corresponding diamines gave rise to the push-pull compounds, C6H4(NEt)2B-1,4-C6H4-B(NFAr)2C6H4 (FAr = C6F5 11; 4-C5F4N 12) and C6H4(NEt)2B-2,5-C4H2S-B(NFAr)2C6H4 (FAr = C6F5 13; 4-C5F4N 14). The X-ray structures of 8, 11, 12 and 13 were determined. Electronic structure calculations reveal that the LUMOs are located at the perfluoroaryl groups in 5-14; thus the fluorinated benzodiazaborolyl groups are considered as electron-withdrawing moieties. These moieties differ from alkylated benzodiazaborolyl groups which are regarded as donors. The emission spectra for 5-14 show charge transfer bands with significant solvatochromism and large Stokes shifts (6100-12 500 cm-1 in cyclohexane and 8900-15 900 cm-1 in CH2Cl2). The emissions of the benzodiazaboroles, 5-10, arise from a different charge transfer (CT) process to the local charge transfer (LCT) process typically found in many fluorescent benzodiazaboroles. This novel remote charge transfer (RCT) process involving the perfluoroaryl groups is supported by CAM-B3LYP computations. The push-pull systems 11-14 here give fluorescent emissions with moderate to high fluorescence quantum yields (65-97%) that arise from the usual LCT process only. [ABSTRACT FROM AUTHOR]

The syntheses, crystallography and magnetic properties of a series of compounds of formula trans-[FeII(L1)2(NCX)2] (X = S, Se, BH3 (1–3)), cis-[FeII(L2)(NCX)2]·CH2Cl2 (X = S, Se, BH3 (4–6)) and trans-[FeII(L3)(NCX)2]n (X = S, Se (7–8)) are described (L1 = 6-chloro-N2,N2-diethyl-N4,N4-di(pyridin-2-yl)-1,3,5-triazine-2,4-diamine, L2 = 6,6′-(1,4,10,13-tetraoxa-7,16-diazacyclooctadecane-7,16-diyl)bis(N2,N2-diethyl-N4,N4-di(pyridin-2-yl)-1,3,5-triazine-2,4-diamine, L3 = 6,6′-(1,4,10,13-tetraoxa-7,16-diazacyclooctadecane-7,16-diyl)bis(N2,N2,N4,N4-tetra(pyridin-2-yl)-1,3,5-triazine-2,4-diamine)). The magnetostructural properties of 1–8 have been probed in detail by variable temperature magnetic measurements and crystallographic methods. 1–6 display mononuclear structures while 7 and 8 form 1-D chain structures. Complexes 4–6 have the potential to form 1D-chains via L2 bridging, but instead form mononuclear complexes. Magnetic studies show that complexes 1, 2, and 4 remain in the high-spin (HS) state at all temperatures. An aged, dry, powdered sample of 3 gives an abrupt HS to LS transition (T1/2 = 200 K), while a freshly prepared, powdered sample of 3·1.5H2O displays thermal hysteresis (Δ = 7 K). Complexes 5, 6 and 7 undergo a gradual spin transition with T1/2 values of 100 K, 150 K and 130 K, respectively. Cooperativity parameters are compared, with 3 showing cooperativity (positive C) and 5 and 6 showing anticooperativity. Photomagnetic LIESST (light induced excited spin state trapping) studies were performed on complexes 5 and 6 and reveal T(LIESST) values lower than 60 K. An attempt has been made to understand the electronic structure of complex 3 and its cooperativity behaviour using density functional methods, the calculations reproducing the sign and, in part, the magnitude of the cooperativity. [ABSTRACT FROM AUTHOR]

Hypodentate diamine cobalt(iii) pentammine complexes [Co(NH3)5(NH2(CH2)nNH3)](ClO4)4 (8: a: n = 3; b: n = 4; c: n = 6; d: n = 8) have been synthesized via the reaction of [Co(NH3)5(OTf)](OTf)2 (TfOH = CF3SO3H) with the corresponding diamines. The analogous t-boc protected diamine complexes [Co(NH3)5(NH2(CH2)nNHt-boc)](ClO4)3 (7a–d) were prepared in 4–26% yield. Low yields for the formation of 7a–d are due to competing side reactions which also gave [Co(NH3)6]3+. Complexes 7a–d were deprotected using trifluoroacetic acid to give the corresponding hypodentate diamine complexes [Co(NH3)5(NH2(CH2)nNH3)](CF3CO2)0.5(ClO4)3.5 (9a–d). HBTU coupling of 8c with N-(t-boc)-l-phenylalanine gave an amino acid functionalized cobalt pentammine complex [Co(NH3)5(NH2(CH2)6NHt-boc)-l-phenylalanine)](ClO4)3 (10). All new complexes were characterized using UV-vis and 1H NMR spectroscopy, and elemental analysis. Grafting of 8c onto 2.4 mm poly(ethylene-co-acrylic acid) (PEAA) beads was achieved via amide coupling. Complex 8c was coupled to thioctic acid via amide coupling and the resulting cobalt disulfide complex [Co(NH3)5(N-(6-aminohexyl)-5-(1,2-dithiolan-3-yl)pentanamide)](ClO4)3 (11) was attached to 10 nm Au nanoparticles. The amount of cobalt loading onto PEAA beads and Au nanoparticles was determined using ICP-MS and EDX. [ABSTRACT FROM AUTHOR]

Reactions of benzoyl pyridine, o-phenylenediamine and anhydrous ZnX2 in methanol afford imine complexes [Zn(L1)X2] (X = Cl, 1; X = Br, 2) in good yields (L1 = (E)-N1-(phenyl(pyridin-2-yl)methylene)benzene-1,2-diamine). The reduction of 1 with NaBH4 affords (E)-N1-(phenyl(pyridine-2-yl)methylene)benzene-1,2-diamine (L2H). The reaction of L2H with [RuII(PPh3)3Cl2] results in the oxidative dehydrogenation to L1 generating cis-[RuII(L1)(PPh3)Cl2] (3). The reaction of L2H with salicylaldehyde affords (E)-2-(((2-((phenyl(pyridin-2-yl)methyl)amino)phenyl)imino)methyl)phenol (L3H2). The reaction of L3H2 with anhydrous FeCl3 in CH3OH affords cis-[FeIII(L3H−)Cl2] (4). Reaction of L3H2 with [RuII(PPh3)3Cl2] results in the oxidative dehydrogenation to diimine, L4H, affording trans-[RuII(L4−)(PPh3)2]+, which is isolated as trans-[RuII(L4−)(PPh3)2]PF6 (5+PF6−) (L4H = 2-((E)-(2-((E)-phenyl(pyridin-2-yl)methyleneamino)phenylimino)methyl)phenol). The reduction of L3H2 with NaBH4 produces 2-(((2-((phenyl(pyridin-2-yl)methyl)amino)phenyl)amino)methyl)phenol (L5H3). With iron(iii) L5H3 undergoes oxidative dehydrogenation to L3H2 affording 4, while with [RuII(PPh3)3Cl2], L5H3 undergoes 4e + 4H+ transfer giving 5+. A fluid solution of L3H2 at 298 K exhibits an emission band at 470 nm (λex = 330 nm, τ1 = 3.70 ns) and a weaker band at 525 nm (λex = 330, 390 nm, τ1 = 1.1 ns) at higher concentrations due to molecular aggregation, which are temperature dependent. 4 is brightly emissive (λex = 330 nm, λem = 450 nm, Φ = 0.586, τ1 = 3.70 ns). Time resolved emission spectra (TRES) and lifetime measurements confirm that the lower energy absorption band of L3H2 at 390 nm, which is absent in complex 4, has a larger non-radiative rate constant (knr). The redox innocent AlIII adduct of L3H2 is fluorescent (λex = 330 nm, λem = 450 nm, τ1 = 3.70 ns). On the contrary, the cis-[FeII(L3H−)Cl2]− and cis-[Co(L3H−)Cl2]− analogues are non emissive. Density function theory (DFT) calculations, redox potentials and the near infra-red (NIR) absorption data prove that 4 is emissive due to the stable [FeIII(L3H−*)] state, while 3, 5+, cis-[FeII(L3H−)Cl2]− and cis-[Co(L3H−)Cl2]− are non-emissive due to transformations of the [MII(L*)] to [MIII(LṖ−*)] states. [ABSTRACT FROM AUTHOR]