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[Pb{Mn(CO)5}3][AlCl4] containing a trigonal planar PbMn3 cluster was obtained by the reaction of PbCl2 and Mn2(CO)10 in the ionic liquid [BMIm][AlCl4]. The title compound is composed of [Pb{Mn(CO)5}3]+ carbonyl cations and [AlCl4]− anions that are connected to infinite zig-zag chains. The [Pb{Mn(CO)5}3]+ cation exhibits a central PbMn3 cluster with three equal Pb–Mn single bonds, resulting in an almost equilateral triangle of three manganese atoms with a formal Pb+I in its center. Such a cluster and compound were identified for the first time. In addition to single-crystal structure analysis, the composition, structure and properties were further characterized by density functional theory (DFT) calculations, energy dispersive X-ray spectroscopy (EDXS), and Fourier-transform infrared spectroscopy (FT-IR), as well as optical spectroscopy (UV-Vis). [ABSTRACT FROM AUTHOR]

Abstract: Ring opening of protected 3-aminoalkyl-substituted azetidin-2-ones with O-, N- or S-nucleophiles led to β,β′-diaminocarboxylic esters, amides and thioesters, respectively. The reaction outcome is improved by the addition of catalytic amounts of sodium azide. Utilization of a glycine derivative with unprotected amino function as nucleophile was possible. When bulkier amino acid esters were used, the intermediate acid azide underwent a Curtius rearrangement. The isocynates formed were trapped as the corresponding urea derivatives. Reduction of β-lactam''s amide moiety led to diaminoalcohols. [Copyright &y& Elsevier]

Ring opening of protected 3-aminoalkyl-substituted azetidin-2-ones with O-, N-, or S-nucleophiles led to β,β′-diaminocarboxylic esters, amides, and thioesters, respectively. The reaction outcome is improved by addition of catalytic amounts of sodium azide. Reduction of the β-lactam amide moiety led to diamino alcohols. [ABSTRACT FROM AUTHOR]

The silylated ferrocenyl selenium reagent 1,1′-Fe(η5-C5H4SeSiMe3)2 has been used for the high yield formation of the phosphine-ligated copper complexes Cu2(fcSe2)(PtPr3)2 (1) and Cu4(fcSe2)2(PnPr3)4 (2) from solublilized CuOAc, as determined by single-crystal X-ray diffraction. The incorporation of a source of Se2- into the reaction scheme with the reagent Se(SiMe3)2 yields the mixed selenide/ferrocenyldiselenolate cluster [Cu20Se6(Se2fc)4(PnPr3)10] (3). Partial substitution of the PnPr3 ligand shell in 3 with the phosphinothiol Ph2P(CH2)3SH leads to an expansion of the framework and the high yield formation of the crystallographically characterized cluster Cu36(fcSe2)6Se12(PnPr3)10(Ph2P(CH2)3SH)2 (5), which contains surface alkylthiol groups on a copper-selenium core. [ABSTRACT FROM AUTHOR]

Studies the syntheses of Ru-S clusters with kinetically labile ligands via photolysis. Derivatives; Attempted synthesis; Electrochemistry.

The synthesis, molecular structures and luminescence properties of two 'Cu12S6' cluster molecules with stabilizing bidentate phosphine ligands are described. Both display in the solid state at ambient temperature high photoluminescence quantum yields (≥48%) and good stability towards oxygen. [ABSTRACT FROM AUTHOR]

Chiral organic molecules possessing high quantum yields, circular dichroism, and circularly polarized luminescence values have great potential as optically active materials for future applications. Recently, the identification of a promising class of inherently chiral compounds was reported, namely macrocyclic 1,3‐butadiyne‐linked pseudo‐meta[2.2]paracyclophanes, displaying high circular dichroism and related gabs values albeit modest quantum yields. Increasing the quantum yields in an attempt to get bright circularly polarized light emitters, the high‐yielding heterocyclization of those 1,3‐butadiyne bridges resulting in macrocyclic 2,5‐thienyls‐linked pseudo‐meta [2.2]paracyclophanes is herein described. The chiroptical properties of both, the previously reported 1,3‐butadiyne, and the novel 2,5‐thienyl bridged macrocycles of various sizes, are experimentally recorded, and theoretically described using density‐functional theory. [ABSTRACT FROM AUTHOR]

A novel mononuclear palladium(II) complex, [Pd(L)Cl2]·DMF (1·DMF, L = 1,4-bis(5-amino-1,3,4-thiadiazol-2-sulfanyl-methyl)benzene), has been synthesized and characterized by elemental analysis, FT-IR and 1H NMR spectroscopy and single-crystal X-ray diffraction. On the basis of the molecular structure, in 1·DMF, a ligand acts as a bidentate chelating one using its endocyclic nitrogen atoms. The biological activities of the free ligand and its palladium complex including cytotoxic activity towards the human colon cancer cell line (HCT-116) and antibacterial activity against one Gram-negative strain (Escherichia coli (ATCC 25922)) and one Gram-positive strain (Staphylococcus aureus (ATCC 6538)) have been examined. The IC50 value of 1·DMF against HCT-116 was 500 μM, which is much higher than that reported for cisplatin, and hence, the compound exhibited low anticancer efficacy compared to cisplatin. However, it exhibited excellent antibacterial activities against both Gram-negative as well as Gram-positive bacterial microorganisms. Furthermore, the thermal stability of complex 1·DMF was studied by thermal gravimetric analysis (TGA). The resulting product was characterized as highly pure PdO nanoparticles (mean crystallite size: 39 nm) by using a series of techniques including powder XRD, EDAX, and SEM. [ABSTRACT FROM AUTHOR]

The historical roots, the discovery and the modern relevance of Dmitri Mendeleev's remarkable advance have been the subject of numerous scholarly works. Here, with a brief overview, we hope to provide a link into the contents of this special issue honouring the great scientist. Mendeleev's advance, announced in March 1869, as he put it in 1889, to the ' . . . then youthful Russian Chemical Society . . . ', first set out the very basis of the periodic law of the chemical elements, the natural relation between the properties of the elements and their atomic weights. This was, and still is, the centrepiece of a historical journey for chemistry to today's position as a pre-eminent science. [ABSTRACT FROM AUTHOR]

Eight [CNN] pincer nickel NHC chlorides, [RCcarbeneNamidoR′2Namine–Ni–Cl] (R/R′2 = quinolinyl/nBu (3a), quinolinyl/Me (3b), quinolinyl/PhCH2 (3c), (CH2)4/nBu (5a), (CH2)4/iPr (5b), Me2/nBu (5c), Me2/iPr (5d), and Me2/PhCH2 (5e)), were prepared by the reactions of related asymmetric [CNN] NHC preligands with Ni(DME)Cl2via N–H bond activation. The molecular structures of complexes 3a, 3b and 5a were investigated using single crystal XRD. The catalytic experiments showed that the nickel complexes could catalyze the hydrosilylation of unsaturated compounds like aldehydes and ketones, and complex 3b was found to exhibit the best catalytic activity at 30 °C. Using NaBHEt3 as an additive, the catalytic activity of 3b was greatly improved. Furthermore, it was found that good to complete conversion of aldehydes could be achieved within 1.5 h at 30 °C after pre-reacting 3b and NaBHEt3 with silane for 0.5 h. The substrate ketones could be converted to alcohols in good yields by prolonging the reaction time to 2.5 h at 30 °C. It is worth mentioning that all eight [CNN] pincer nickel NHC chlorides are stable in air, and this is rare in nickel catalysts for hydrosilylation of aldehydes and ketones. Moreover, the substrate universality of the catalytic system is also very good, with good functional group tolerance. The molecular structures of complexes 3a, 3b and 5a were investigated using single crystal XRD and a possible reaction mechanism was proposed. [ABSTRACT FROM AUTHOR]

The exploration of new materials is timeless. Especially 2D‐materials have gotten much interest in the last decades. This work proposes a new route towards a fascinating class of 2D materials: molecular textiles. The suggested bottom‐up approach focuses on the 2D self‐assembly of a cross‐shaped monomer at the water/air interface. A 3D cross‐shaped motive was designed, synthesized, and characterized, which exhibits the required structural features, i. e., static and dynamic control. Analysis of the cross‐shaped motive by 1H‐NMR spectroscopy, X‐ray structure, and chiral stationary phase HPLC proved the rigidity and stability of the system, and thus also its potential for the here suggested new strategy towards molecular textiles. Three variants of a Schiff‐base precursor pair functionalized monomer were synthesized and characterized by 1H‐NMR spectroscopy, 13C‐NMR spectroscopy, and mass spectrometry. Finally, the network formation of the monomer is shown to be triggered by deprotonation of its ammonium salt, corroborated with FT‐IR analysis. [ABSTRACT FROM AUTHOR]

Orthogonal joints, understood as connections with an angle of 90°, were introduced in the design of the "Geländer" model compounds 1 and 2. The banister, consisting of a conjugated carbazole dimer linked by either 1,3‐butadiyne (2) or a single thiophene (1), wraps around an axis composed of a phthalimide dimer due to the dimensional mismatch of both subunits, which are interconnected by phenylene rungs. The "Geländer" structure was assembled from a monomer comprising the 1,4‐diaminobenzene rung with one amino substituent as part of a 4‐bromo phthalimide subunit forming the orthogonal junction to the axis, and the other as part of a masked 2‐ethynyl carbazole as orthogonal joint to the banister. The macrocycle was obtained by two sequential homocoupling steps. A first dimerization by a reductive homocoupling assembled the axis, while an oxidative acetylene coupling served as ring‐closing reaction. The formed butadiyne was further derivatized to a thiophene, rendering all carbons of the model compound sp2 hybridized. Both helical structures were fully characterized and chirally resolved. Assignment of the enantiomers was achieved by simulation of chiroptical properties and enantiopure synthesis. [ABSTRACT FROM AUTHOR]

The synthetic access to macrocyclic molecular topologies with interesting photophysical properties has greatly improved thanks to the successful implementation of organic and inorganic corner units. Based on recent reports, we realized that pseudo‐meta [2.2]paracyclophanes (PCPs) might serve as optimal corner units for constructing 3D functional materials, owing to their efficient electronic communication, angled substituents and planar chirality. Herein, we report the synthesis, characterization and optical properties of four novel all‐carbon enantiopure macrocycles bearing three to six pseudo‐meta PCPs linked by 1,3‐butadiyne units. The macrocycles were obtained by a single step from enantiopure, literature‐known dialkyne pseudo‐meta PCP and were unambiguously identified and characterized by state of the art spectroscopic methods and in part even by x‐ray crystallography. By comparing the optical properties to relevant reference compounds, it is shown that the pseudo‐meta PCP subunit effectively elongates the conjugated system throughout the macrocyclic backbone, such that already the smallest macrocycle consisting of only three subunits reaches a polymer‐like conjugation length. Additionally, it is shown that the chiral pseudo‐meta PCPs induce a remarkable chiroptical response in the respective macrocycles, reaching unprecedented high molar circular dichroism values for all‐carbon macrocycles of up to 1307 L mol−1 cm−1. [ABSTRACT FROM AUTHOR]

Two silyl [P,Si]‐chelate cobalt hydrides, [(o‐Si(Ph)2‐(PiPr2)C6H4)Co(H)(PMe3)2] (1) and [(o‐Si(Ph)2‐(PPh2)C6H4)Co(H)(PMe3)2] (2), were prepared through the chelate‐assisted Si–H activation of bidentate preligand, o‐HSi(Ph)2‐(PiPr2)C6H4 (L1) and o‐HSi(Ph)2‐(PPh2)C6H4 (L2) by [Co(PMe3)4] or [Co(Me)(PMe3)4], respectively. Both cobalt(II) hydrides 1 and 2 can efficiently catalyze hydrosilylation of olefins, and the catalytic effect of complex 1 is better than that of complex 2. The Markovnikov products were formed from aryl alkenes, whereas the anti‐Markovnikov products were produced from aliphatic alkenes. In the mechanism study, a silyl cobalt(II) intermediate, [(o‐Si(Ph)2‐(PiPr2)C6H4)Co(SiHPh2)(PMe3)2], as the real catalyst is proposed and supported by in situ infrared (IR) study. The molecular structure of complex 1 was determined by single crystal X‐ray diffraction analysis. [ABSTRACT FROM AUTHOR]

The design and creation of soft porous crystals combining regularity and flexibility may promote potential applications for gas storage and separation due to their deformable framework's responsiveness to external stimuli. The flexibility of metal–organic frameworks (MOFs) relies on alterable degrees of freedom that are mainly provided by organic linkers or the junctions linking organic and inorganic building units. Herein, we report a new dynamic MOF whose flexibility originates from an unprecedented tailorable Mn8O38‐cluster and shows simultaneous coordination geometry changes and ligand migration that are reversibly driven by guest exchange. This provides an extra degree of freedom to the framework's deformation, resulting in three‐dimensional variations in the framework that subtly respond to varied aromatic molecules. The gas adsorption behavior of this flexible MOF was evaluated, and the selective separation of light hydrocarbons and Freon gases is achieved. [ABSTRACT FROM AUTHOR]

The design and creation of soft porous crystals combining regularity and flexibility may promote potential applications for gas storage and separation due to their deformable framework's responsiveness to external stimuli. The flexibility of metal–organic frameworks (MOFs) relies on alterable degrees of freedom that are mainly provided by organic linkers or the junctions linking organic and inorganic building units. Herein, we report a new dynamic MOF whose flexibility originates from an unprecedented tailorable Mn8O38‐cluster and shows simultaneous coordination geometry changes and ligand migration that are reversibly driven by guest exchange. This provides an extra degree of freedom to the framework's deformation, resulting in three‐dimensional variations in the framework that subtly respond to varied aromatic molecules. The gas adsorption behavior of this flexible MOF was evaluated, and the selective separation of light hydrocarbons and Freon gases is achieved. [ABSTRACT FROM AUTHOR]

Highlights: [•] Synthesis of a series of five structurally similar binuclear copper(I) complexes. [•] Investigation of absorption and emission properties. [•] [Cu2(S–C6H4OMe)2(dpppt)2] shows significant luminescence at 465nm. [•] [Cu2(Se–C6H4NMe2)2(dpppt)2] shows significant luminescence at 480nm. [ABSTRACT FROM AUTHOR]

Two derivatives, 3 L and 9 L, of a ditopic, multiply hydrogen-bonding molecule, known for more than a decade, have been found, in the solid state as well as in solvents of low polarity at room temperature, to exist not as monomers, but to undergo a remarkable self-assembly into a complex supramolecular species. The solid-state molecular structure of 3 L, determined by single-crystal X-ray crystallography, revealed that it forms a highly organized hexameric entity 3 L6 with a capsular shape, resulting from the interlocking of two sets of three monomolecular components, linked through hydrogen-bonding interactions. The complicated 1H NMR spectra observed in o-dichlorobenzene ( o-DCB) for 3 L and 9 L are consistent with the presence of a hexamer of D3 symmetry in both cases. DOSY measurements confirm the hexameric constitution in solution. In contrast, in a hydrogen-bond-disrupting solvent, such as DMSO, the 1H NMR spectra are very simple and consistent with the presence of isolated monomers only. Extensive temperature-dependent 1H NMR studies in o-DCB showed that the L6 species dissociated progressively into the monomeric unit on increasing th temperature, up to complete dissociation at about 90 °C. The coexistence of the hexamer and the monomer indicated that exchange was slow on the NMR timescale. Remarkably, no species other than hexamer and monomer were detected in the equilibrating mixtures. The relative amounts of each entity showed a reversible sigmoidal variation with temperature, indicating that the assembly proceeded with positive cooperativity. A full thermodynamic analysis has been applied to the data. [ABSTRACT FROM AUTHOR]

Three novel iron dinitrogen hydrides, [FeH(iPr-PSiMeP)(N2)(PMe3)] (1), [FeH(iPr-PSiPhP)(N2)(PMe3)] (2), and [FeH(iPr-PSiPh)(N2)(PMe3)] (3), supported by a silyl ligand are synthesized for the first time by changing the electronic effect and steric hindrance of the ligands through the reaction of ligands L1–L3 with Fe(PMe3)4 in a nitrogen atmosphere. The ligands containing an electron-donating group with large steric hindrance on the phosphorus atom are beneficial for the formation of dinitrogen complexes. A penta-coordinate iron hydride [FeH(iPr-PSiPh)(PMe3)2] (4) was formed through the reaction of ligand L3 with Fe(PMe3)4 in an argon atmosphere under the same conditions. The reactions between complexes 1–3 with an atmospheric pressure of dihydrogen gas resulted in Fe(II) dihydrides, [(iPr-PSiMe(μ-H)P)Fe(H)2(PMe3)] (5), [(iPr-PSiPh(μ-H)P)Fe(H)2(PMe3)] (6) and [(iPr-PSiPh(μ-H))Fe(H)2(PMe3)2] (7), with an η2-(Si–H) coordination. The isolation of dihydrides 5–7 demonstrates the ability of the dinitrogen complexes 1–3 to realize the activation of dihydrogen under ambient temperature and pressure. The molecular structures of complexes 1–7 were elucidated by single crystal X-ray diffraction analysis. The iron dinitrogen hydrides 1–3 are effective catalysts for the silylation of dinitrogen under ambient conditions and among them 3 is the best catalyst. [ABSTRACT FROM AUTHOR]

In this study, two [PCP] pincer silylene cobalt(I) complexes [((Ph2POCH2)2CH)Co(PMe3)(SiCl((NtBu)2CAr))] (Ar = Ph (2) and 4-MePh (3)) were synthesized through the substitution reaction of the [PCP] pincer cobalt(I) complex [((Ph2POCH2)2CH)Co(PMe3)2] (1) with silylene ligands: SiCl((NtBu)2CAr) (Ar = Ph (L1) and 4-MePh (L2)). The reaction of complex 2 with CO afforded the carbonyl silylene cobalt(I) complex [((Ph2POCH2)2CH)Co(CO)(SiCl((NtBu)2CPh))] (4), while complex 2 reacted with CH3I to give rise to cobalt(II) iodide [((Ph2POCH2)2CH)Co(I)(PMe3)] (6). With a catalyst loading of 2 mol%, complex 6 displayed efficient catalytic activity for hydrosilylation of alkenes by using Ph2SiH2 as the hydrogen source under mild conditions. The molecular structures of complexes 2, 3, 4 and 6 were determined by single crystal X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

Based on the new binuclear gold(I) complex [(AuCl)( L1)] ( 1) ( L1 = 2,3-bis(diphenylphosphino)maleic anhydride) four new polynuclear compounds were synthesized by reactions of 1 with E(SiMe) (E = S, Se). During the formation of these new compounds the initial ligand L1 undergoes various transformations (e.g. substitution, hydration or hydrogenation) leading to the new ligands: trans-2,3-bis(diphenylphosphino)succinic anhydride ( L2), 2-diphenylphosphino-3-mercapto-maleic anhydride anion ( L3), 2-diphenylphosphino-3-selenolato-maleic anhydride anion ( L4) and 2,3-bis(diphenylphosphino)succinic acid ( L5). In case of using the sulfur species S(SiMe) a pentanuclear cluster, [Au(PPh)( L3)] ( 2), and a 24-nuclear cluster, [AuS(PPh)( L3)] ( 3), could be obtained. With Se(SiMe) the binuclear complex, [(AuCl)( L2)] ( 4), and the dodecanuclear cluster, [AuSe( L4)( L5)] ( 5), were yielded. [ABSTRACT FROM AUTHOR]

CuCI and bis(diphenylphosphanyl)metharre (dppm) react in the presence of small amounts of FeCl3 with PhSeSiMe3 and Se(SiMe3)2 to yield [Cu30Fe2Se6(SePh)24(dppm)4]. The crystal structure of the compound was determined by single-crystal X-ray analysis to give a mixed copper selenide/selenolate cluster molecule of a new structural type incorporating Iwo central iron atoms. The formal oxidation state of the iron atoms was determined by Mbssbauer spectroscopy to be +3, in agreement with quantum chemical calculations and modeling of the magnetic data. In addition, Mdssbauer studies show no magnetic hyperfine structure in zero field, and the magnetically perturbed spectrum displays a pattern typical tora diamagnetic species in a transverse field, suggesting a singlet ground state. However, the inclusion of the iron atoms has a distinct influence on the optical properties of the compound compared to similar clusters containing only copper and selenium atoms. [ABSTRACT FROM AUTHOR]

The copper tellurolate cluster [(Cu6(TePh)6(PEtPh2)5] (1) has been loaded into the pores of a trimethylsilylated MCM-41 (TMS–MCM-41) framework. Solutions of 1 in tetrahydrofuran lead to good impregnation weight % (~10 wt%, 1). The resulting material was analysed by powder X-ray diffraction (PXRD), nitrogen sorption isotherms, thermogravimetric analysis (TGA), energy dispersive X-ray (EDX) analysis, 31P CP MAS NMR spectroscopy, and transmission electron microscopy (TEM). It was observed that the loading process proceeds with the intact cluster 1 being present within the hexagonal architecture. The intact nature of 1 makes it an ideal candidate for condensation by photochemical or thermal means. Both of these condensation treatments increase the Cu:Te ratio of 1 to approach that observed in binary semiconductor Cu2Te. The condensation process was analysed by GC–MS spectrometry and characterization of the condensed, isolated composites was performed by TGA, EDX analysis, 31P CP MAS NMR spectroscopy, nitrogen adsorption, and TEM measurements. Thermal condensation results in the formation of Cu2Te particles, whereas photochemical condensation yields larger copper-tellurolate nanoclusters. [ABSTRACT FROM AUTHOR]

Reactions of copper(I) acetate with 2-mercaptothiazoline (HS-thiaz) in the presence of tertiary phosphines lead to the formation of tetranuclear sulphur-bridged copper complexes. Depending on the reaction conditions, isolated clusters ([Cu4(S-thiaz)4(PR3)2] (PR3 = PPh3 (1), PEt2Ph (2), PEt3 (3)), oligomeric compounds ([Cu4(S-thiaz)4]2 (4) and [Cu4(S-thiaz)4]4 (5)), or a one-dimensional polymer ([Cu4(S-thiaz)4]∞ (6)) are formed. The structures of the compounds 2–5 have been determined by single crystal X-ray analysis. [ABSTRACT FROM AUTHOR]

Abstract: Treatment of tetraphosphonitoresorcinarene [(CH3)2CHCH2CHC6H2O2PPh]4 (1) with an excess [CuCl] powder in the presence of pyridine (py) yielded a tetracopper(I) phosphonitocavitand [pyH][1·Cu4(μ-Cl)4(μ 4-Cl)] (2). The Included μ 4-Cl in 2 was easily substituted by heavy halide anion to give [pyH][1·Cu4(μ-Cl)4(μ 4-X)] (X=Br, 3; I, 4). The complexes 2, 3, and 4 have been characterized by X-ray structure determinations. The similar structure contains four coplanar cupper atoms bridged by four μ-Cl and one central trapped μ 4-X atoms in the inside of the closing bowl-shaped cavitand. The third-order nonlinear optical properties of 2 as a typical metal-cavitand complex were investigated in this paper. [Copyright &y& Elsevier]

A novel silylene supported iron hydride [Si, C]FeH (PMe3)3 (1) was synthesized by C (sp3)‐H bond activation with zero‐valent iron complex Fe (PMe3)4. Complex 1 was fully characterized by spectroscopic methods and single crystal X‐ray diffraction analysis. To the best of our knowledge, 1 is the first example of silylene‐based hydrido chelate iron complex produced through activation of the C (sp3)−H bond. It was found that complex 1 exhibited excellent catalytic activity for hydrosilylation of aldehydes and ketones. The catalytic system showed good tolerance and catalytic activity for the substrates with different functional groups on the benzene ring. It is worth mentioning that, the experimental results showed that both ketones and aldehydes could be reduced in good to excellent yields under the same catalytic conditions. Based on the experiments and literature reports, a possible catalytic mechanism was proposed. [ABSTRACT FROM AUTHOR]

The optical properties of a group of cadmium-chalcogenide cluster-molecules with the general formula [Cd10E4(E′Ph)12(PR3)4], (E=Te, Se; E′=Se, S) were studied to investigate the effect of substitution of the chalcogen atoms in positions E and E′. The cluster-molecules were prepared by an organometallic synthesis route and their structures were determined by single crystal X-ray diffraction. The clusters display visible emission only at low temperatures, and the peak position and lifetime of the photoluminescence (PL) depends significantly on the E′ chalcogen atom type. The PL of clusters with outer selenophenyl ligands is centered at 500 nm while for clusters with thiophenyl ligands the emission is shifted to 420 nm, and the emission lifetime is significantly longer. This provides strong support for assigning the emission to forbidden transitions related with the cluster capping ligands. The onset of the absorption and the PL excitation spectra display a systematic blue-shift upon variation of the E and E′ atoms from Te to Se to S. This behavior resembles that of the band gap shift in the respective bulk semiconductors demonstrating that such cluster-molecules manifest a molecular limit of the solid state. [Copyright &y& Elsevier]

The reaction of mixed-ligands 1,2,4,5-benzene tetracarboxylic acid (H 4 btec) and 1,2- bis (4-amino-5-methylmercapto-1,2,4-triazole-3-yl)ethane (bamte) with zinc(II) nitrate hexahydrate under hydrothermal conditions led to the formation of the coordination polymer [Zn 2 (bamte) (btec)] n (CP1), whereas the reaction of the same organic tetraacid with 4-amino-5-(pyridine-4-yl)-4 H -1,2,4-triazole-3-thiol (Haptt) and cadmium (II) nitrate tetrahydrate under solvothermal conditions gave the coordination polymer [Cd 3 (aptt) 2 (btec)] n (CP2). Both CPs have been characterized by elemental analysis, FT−IR, powder X-ray diffraction as well as single-crystal X-ray diffraction. Both complexes possess three-dimensional (3D) networks based on two-dimensional MII-btec4-- layers connected by multidentate triazole moieties. CP1 shows a rarely observed binodal (4,6)-connected " fsc " coordination network with (44.610.8) (44.62) topology, whereas CP2 presents a new tetranodal (4,4,5,6)-connected 3D net with (43.62.8) 2 (44.62) (44.66) 2 (46.66.83) point symbol. Furthermore, the morphology, thermal stability, and solid-state luminescent property of both coordination polymers have been investigated. Image 1 • Preparation of two novel 3D CPs based on H 4 BTEC ligand and 1,2,4-triazoles. • Elucidation of the topology of synthesized coordination polymers (CP1 and CP2). • Investigation on thermal stability and luminescence properties of CP1 and CP2. [ABSTRACT FROM AUTHOR]

Studies the crystal structure of acetonitrile[2,6-bis(pyrazol-1-y)pyridine](isonicotinamide) copper(II) cation. Conformation of the pyridine ring of the isonicotinamide ligand; Structural parameters of the hydrogen-bonded contacts.

Examines the class of ruthenium sulfide clusters. Characterization of clusters in nitrogenase; Administration of chromatographic purification of hydrolyzed samples; Formation of rationalized conformation of H[sub 2].

Five [PSiP]-pincer iron hydrides 1–5, [(2-Ph2PC6H4)2HSiFe(H)(PMe3)2 (1), (2-Ph2PC6H4)2MeSiFe(H)(PMe3)2 (2), (2-Ph2PC6H4)2PhSiFe(H)(PMe3)2 (3), (2-(iPr)2PC6H4)2HSiFe(H)(PMe3) (4), and (2-(iPr)2PC6H4)2MeSiFe(H)(PMe3)2 (5)], were used as catalysts to study the effects of pyridine N-oxide and the electronic properties of [PSiP]-ligands on the catalytic hydrosilylation of carbonyl compounds. It was proved for the first time that this catalytic process could be promoted with pyridine N-oxide as the initiator at 30 °C because the addition of pyridine N-oxide is beneficial for the formation of an unsaturated hydrido iron complex, which is the key intermediate in the catalytic mechanism. Complex 4 as the best catalyst shows excellent catalytic performance. Among the five complexes, complex 3 was new and the molecular structure of complex 3 was determined by single crystal X-ray diffraction. A proposed mechanism was discussed. [ABSTRACT FROM AUTHOR]

The dehydration of primary amides to their corresponding nitriles using four [PSiP]‐pincer hydrido iron complexes 1–4 [(2‐Ph2PC6H4)2MeSiFe(H)(PMe3)2 (1), (2‐Ph2PC6H4)2HSiFe(H)(PMe3)2 (2), (2‐(iPr)2PC6H4)2HSiFe(H)(PMe3)2 (3) and (2‐(iPr)2PC6H4)2MeSiFe(H)(PMe3)2 (4)] as catalysts in the presence of (EtO)3SiH as dehydrating reagent was explored in the good to excellent yields. It was proved for the first time that Lewis acid could significantly promote this catalytic system under milder reaction conditions than other Lewis acid‐promoted system, such as shorter reaction time or lower reaction temperature. This is also the first example that dehydration of primary amides to nitriles was catalyzed by silyl hydrido iron complexes bearing [PSiP]‐pincer ligands with Lewis acid as additive. This catalytic system has good tolerance for many substituents. Among the four iron hydrides 1 is the best catalyst. The effects of substituents of the [PSiP]‐pincer ligands on the catalytic activity of the iron hydrides were discussed. A catalytic reaction mechanism was proposed. Complex 4 is a new iron complex and was fully characterized. The molecular structure of 4 was determined by single crystal X‐ray diffraction. [ABSTRACT FROM AUTHOR]

The bidentate phosphine bis(diphenylphosphino)-N-phenyl-maleimide (L1) is used to synthesize a series of complexes from coinage metals and palladium. Some of them are mononuclear species where one metal atom is coordinated by two phosphine ligands. Three of these complexes have been investigated in detail because they contain the initial ligand in an anionic, radical form (L1′) i.e. [Cu(L1L1′)] (1), [Ag(L1L1′)] (7), [Pd(L1′)2] (11). L1′ in 1, 7 and 11 shows significant differences in its bonding parameters compared to free or coordinating L1. By magnetic measurements the radical nature of these three compounds could be verified. Quantum chemical calculations prove the existence of either one (1 and 7) or two (11) unpaired electrons localized on the ligand. Furthermore these calculations can explain that 1 and 7 show an asymmetric structure in solid state where one can clearly differ L1 from L1′. [ABSTRACT FROM AUTHOR]

Thiol‐ and solvent‐coordinated cation exchange kinetics have been applied to engineer the composition and crystallinity of novel nanocrystals. The detailed thermodynamics and kinetics of the reactions were explored by NMR spectroscopy, time‐dependent photoluminescence (PL) characterizations and theoretical simulations. The fine structure of the colloidal semiconductor nanocrystals (CSNCs) was investigated by X‐ray absorption near‐edge structure (XANES) and extended X‐ray absorption fine structure (EXAFS). In this way, high‐quality p‐type Ag‐doped ZnS quantum dots (QDs) and Au@ZnS hetero‐nanocrystals with a cubic phase ZnS shell were synthesized successfully.The unprecedented dominant Ag+‐dopant‐induced fluorescence and p‐type conductivity in the zinc‐blende ZnS are reported. The right combination of thiol and solvent allows the resulting nanocrystal to be engineered by modulating the cation exchange kinetics. By applying this method, high‐quality p‐type Ag‐doped ZnS quantum dots (QDs) and Au@ZnS hetero‐nanocrystals with a cubic phase ZnS shell were synthesized successfully. [ABSTRACT FROM AUTHOR]

Exploring efficient photocatalysts for water oxidation is highly demanded because of their significant role in artificial photosynthesis. The research of metal-organic frameworks (MOFs) based photoelectrochemical (PEC) water splitting is promising but still in its infancy due to the challenge to fabricate high-quality MOFs photoelectrode. Here an Fe 2 O 3 /Fe-based MOF core/shell nanorod is prepared for efficient PEC water oxidation via a facile surfactant-assisted solvothermal method. With polyvinylpyrrolidone (PVP) molecules as intermedia, an ultrathin MOF shell of several nanometers thick can be controllably grown on the surface of Fe 2 O 3 nanorod. Charge dynamical behaviors study by ultrafast transient absorption spectroscopy (TAS) and photoelectrochemical impedance spectroscopy (PEIS), reveal that the ultrathin MOF shell is crucial to promote the charge separation by providing a cascade band level, but also accelerate the hole injection efficiency via exposing more accessible Fe-oxo cluster active sites. Accompanied with good visible-light response, the Ti-doped Fe 2 O 3 /NH 2 -MIL-101(Fe) photoanode delivers a boosted photocurrent density of 2.27 mA cm −2 at 1.23 V vs. RHE, which is about 2.3 folds of that of pristine Fe 2 O 3 . This study provides new insights into the rational design of semiconductor/MOFs hybrid materials for photo/photoelectrochemical catalysis. [ABSTRACT FROM AUTHOR]

A new synthetic strategy for the novel diphosphine-phosphine oxide ligand (1) (Ph2P-(C6H4))2P(O)H was designed. A series of [PPP]-pincer Fe, Ni, and Co complexes were prepared. All of them were formed by chelate-assisted P–H activation. Two metal hydrides [(Ph2P-(C6H4))2P(O)]Fe(H)(PMe3)2 (2) and [(Ph2P-(C6H4))2P(O)]Ni(H)(PMe3) (3) were obtained at room temperature. The combination of ligand 1 with Co(PMe3)4Me or Co(PMe3)4 afforded the same Co(i) complex [(Ph2P-(C6H4))2P(O)]Co(PMe3)2 (4) via P–H bond activation. The catalytic performance of the Fe, Ni, and Co complexes for the hydrosilylation of aldehydes and ketones was explored. At a catalyst loading of 2 mol%, complex 2 displayed the best catalytic activity for the hydrosilylation by using (EtO)3SiH as the hydrogen source under mild conditions. Complexes 2, 3, and 4 were characterized by spectroscopic methods and X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

Polyfluorinated aryl imines 2,4,5-R1,R2,R3-C6H2-HC=N-1-C10H7 (R1 = F, R2 = F, R3 = H (1); R1 = F, R2 = H, R3 = F (2) and R1 = F, R2 = F, R3 = F (3)) and F5C6-HC=N-1-C10H7 (7) reacted with CoMe(PMe3)4 to give rise to hydrido [CNC]-pincer cobalt(iii) complexes (2,4,5-R1,R2,R3-C6H-HC=N-1-C10H6)Co(H)(PMe3)2 (R1 = F, R2 = F, R3 = H (4); R1 = F, R2 = H, R3 = F (5); R1 = F, R2 = F, R3 = F (6)) and (F4C6-HC=N-1-C10H6)Co(H)(PMe3)2 (8) via selective C–F/C–H bond activation. Penta-coordinate dicarbonyl cobalt(i) complexes (2,4,5-R1,R2,R3-C6H-HC=N-1-C10H7)Co(CO)2(PMe3) (R1 = F, R2 = H, R3 = F (9); R1 = F, R2 = F, R3 = F (10)) were obtained from reactions of hexa-coordinate cobalt(iii) complexes 5 and 6 with carbon monoxide through reductive elimination. Cobalt(iii) halides (2,4,5-R1,R2,R3-C6H-HC=N-1-C10H6)Co(i)(PMe3)2 (R1 = F, R2 = F, R3 = H (11); R1 = F, R2 = H, R3 = F (12); R1 = F, R2 = F, R3 = F (13)) and (2,4,5-R1,R2,R3-C6H-HC=N-1-C10H6)Co(Br)(PMe3)2 (R1 = F, R2 = F, R3 = H (14); R1 = F, R2 = H, R3 = F (15); R1 = F, R2 = F, R3 = F (16)) were prepared by the interaction between hydrido cobalt(iii) complexes 4–6 and MeI or EtBr. The molecular configurations of complexes 4, 8, and 11 were determined by single crystal X-ray diffraction. We then confirmed that the four hydrido cobalt(iii) complexes 4–6 and 8 could be used as catalysts for reduction of aldehydes and ketones. Complex 8 is the best catalyst among the four complexes and can selectively catalyze the carbonyl groups of α,β-unsaturated aldehydes and ketones. [ABSTRACT FROM AUTHOR]

Three novel selenophenolato hydrido iron(II) complexes [ cis -(H)(SeAr)Fe(PMe 3 ) 4 ] ( 4–6 ) (Ar=C 6 H 5 ( 4 ), p -MeOC 6 H 4 ( 5 ) and o -MeC 6 H 4 ( 6 )) were prepared through the reaction of Fe(PMe 3 ) 4 with selenophenols ArSeH ( 1–3 ) via Se–H activation. The iron hydrido complexes 4 , 5 and 6 could catalyze the hydrosilylation of aldehydes and ketones. Among them complex 5 is the best catalyst for this process. Furthermore, α,β-unsaturated alcohols could be obtained from the selective reduction reactions of the corresponding α,β-unsaturated carbonyls catalyzed by hydrido iron(II) complex 5 . This catalytic system has good tolerance for some common groups but it is easy to reduce the nitro group to an amino group. The experiments indicate that the chemoselectivity for this catalytic system is CHO> NO 2 > C( O)CH 3 . The crystal structure of 6 was determined by X-ray diffraction. [ABSTRACT FROM AUTHOR]

Three novel η 3 -2-azaallyl iron(I) complexes, [(2-PPh 2 )C 6 H 4 ](CH=N-CH)C 6 H 4 (4-R)]Fe(PMe 3 ) 2 ( 4 - 6 ) (R = H ( 4 ), Cl ( 5 ) and OMe ( 6 )), were prepared through the reactions of Schiff base preligands [(2-PPh 2 )C 6 H 4 ](CH=NCH 2 )C 6 H 4 (4-R)] ( 1 - 3 ) (R = H ( 1 ), Cl ( 2 ) and OMe ( 3 )) with Fe(PMe 3 ) 4 via sp 3 C-H bond activation under mild reaction conditions. Compared with the reported 2-azaallyl cobalt complexes, these are the first 2-azaallyl iron(I) complexes obtained via Csp 3 -H bond activation. Complex [(2-PPh 2 )C 6 H 4 ](CH=N-CH) (C 6 H 4 )FeBr(PMe 3 ) 2 ( 7 ) was obtained through the reaction of 4 with EtBr. The ligand replacement reaction of complex 4 with CO delivered the dicarbonyl iron(I) complex [(2-PPh 2 )C 6 H 4 ](CH-N=CH) (C 6 H 5 )Fe(CO) 2 (PMe 3 ) ( 8 ). The molecular structures of complexes 4 and 6 were determined by single crystal X-ray diffraction. [ABSTRACT FROM AUTHOR]

C(carbene)N(amido)N(amine)-pincer nickel(ii) complexes [iPrCNN-Ni-Br] (6), [nBuCNN-Ni-Br] (7) and [BnCNN-Ni-Cl] (8) were synthesized. The catalytic performance of complexes 6–8 for Sonogashira cross-coupling reactions was explored. In a combination of 5 mol% catalyst loading of 6 and CuI/Cs2CO3/NaI/DMSO at different temperatures for the coupling reactions between alkyl iodides, bromides, chlorides and terminal alkynes, the corresponding coupling products were obtained in moderate to excellent yields. The mechanism of these catalytic reactions was discussed and partially supported by experiments. The phenylethynyl CNN pincer nickel complex 9 as a catalytically active complex was isolated and structurally characterized using X-ray diffraction. [ABSTRACT FROM AUTHOR]

A discrete binuclear copper complex with nitrogen‐rich double rings has been synthesized by ether diffusion method, which was characterized by single crystal X‐ray diffraction. The crystal structure exhibits two connected rings as Arabic numeral "8" shape and stacks each other in the lattice leading to channels for ion sorption. Furthermore, this crystalline material is recoverable and displays high stability in water. The thermal stability has been confirmed by variable temperature powder X‐ray diffraction (VT‐PXRD). Flame atomic absorption spectrometry (FAAS) study has been carried out to confirm the ability of mercury(II) capture from aqueous solution, showing that the porous crystals have good adsorption capacity. The ion sorption kinetic process has been investigated, revealing a pseudo‐second‐order kinetics of mercury(II) adsorption. [ABSTRACT FROM AUTHOR]

The hydrido silyl iron complex (o-Ph2PC6H4SiMe2)Fe(PMe3)3H (2) was obtained via the activation of the Si–H bond of the bidentate silyl ligand o-Ph2P(C6H4)SiMe2H (1) by Fe(PMe3)4. 2 showed good to excellent catalytic activity in both the reduction of aldehydes/ketones and the dehydration of benzamide. In addition, with complex 2 as a catalyst, α,β-unsaturated carbonyls could be selectively reduced to the corresponding α,β-unsaturated alcohols. The mechanisms of the formation of 2 and the catalytic dehydration process are proposed and partly experimentally verified. [ABSTRACT FROM AUTHOR]

Two novel cobalt Schiff base complexes 3 and 4, ((2-PPh2)C6H4)C=N(C10H7)Co(PMe3)2 (3) and ((2-PPh2)C6H4)CH=N(C6H5)Co(PMe3)2 (4) with η2(C–H) coordination, were synthesized by the reactions of Schiff base preligands ((2-PPh2)C6H4)CH=N(C10H7) (1) and ((2-PPh2)C6H4)CH=N(C6H5) (2) with CoMe(PMe3)4via sp2 C–H bond activation. Under similar reaction conditions, the reactions of Co(PMe3)4 with 1 and 2 gave rise to the simple π-(C=N)-coordinated cobalt(0) complexes ((2-PPh2)C6H4)CH=N(C10H7)Co(PMe3)2 (5) and ((2-PPh2)C6H4)CH=N(C6H5)Co(PMe3)2 (6). Complex ((2-PPh2)C6H4)C=N(C10H6)CoI(PMe3)2 (7) was obtained through the reaction of 3 with iodomethane via the activation of the second C–H bond in 1. The substitution reaction of complex 3 with carbon monoxide afforded the dicarbonyl cobalt(i) complex ((2-PPh2)C6H4)C=N(C10H7)Co(CO)2(PMe3) (8). The molecular structures of 4, 5, 7 and 8 were determined by single-crystal X-ray diffraction. [ABSTRACT FROM AUTHOR]

A novel Co(III) complex ( o -(Ph 2 P)C 6 H 4 ) 3 SiCoHCl ( 2 ) was synthesized by reaction of tris(phosphino)silyl ligand ( o -(Ph 2 P)C 6 H 4 ) 3 SiH ( 1 ) and CoCl(PMe 3 ) 3 with Si–H bond activation. Complex 2 was very stable to CO or CH 3 I. Co(I) complex ( o -(Ph 2 P)C 6 H 4 ) 3 SiCo(PMe 3 ) ( 3 ) could be isolated in a yield of 72% when treatment of 2 with one equivalent of CH 3 Li in the presence of one equivalent of PMe 3 with the formation of LiCl and the escape of one molecule of methane. Complex 3 could also be obtained by the reaction of 1 with Co(PMe 3 ) 4 or CoMe(PMe 3 ) 4 via elimination of H 2 or CH 4 . The molecular structures of complexes 2 and 3 were determined by single crystal X-ray diffraction. Complex 2 has catalytic reactivity to the Kumada cross-cupling reactions. [ABSTRACT FROM AUTHOR]

The electron-rich silylene Co(i) chloride 5 was obtained through the reaction of CoCl(PMe3)3 with chlorosilylene. Complex 5 reacted with 1,3-siladiazole HSiMe(NCH2PPh2)2C6H4 to give the silylene Co(iii) hydride 6 through chelate-assisted Si–H activation. To the best of our knowledge, complex 6 is the first example of Co(iii) hydride supported by N-heterocyclic silylene. Complexes 5 and 6 were fully characterized by spectroscopic methods and X-ray diffraction analysis. Complex 6 was used as an efficient precatalyst for Kumada cross-coupling reactions. Compared with the related complex 3 supported by only trimethylphosphine, complex 6 as a catalyst supported by both chlorosilylene and trimethylphosphine exhibits a more efficient performance for the Kumada cross-coupling reactions. A novel catalytic radical mechanism was suggested and experimentally verified. As an intermediate silylene cobalt(ii) chloride 6d was isolated and structurally characterized. [ABSTRACT FROM AUTHOR]

The reaction between 2-pyridinetetramethyldisilazane 1 and CoMe(PMe 3 ) 4 led to the formation of the novel bissilyl cobalt(III) hydride CoH((C 5 H 4 N)-N(SiMe 2 ) 2 )(PMe 3 ) 3 ( 2 ) via the cleavage of two Si-H bonds with the elimination of methane. The reaction of phenyltetramethyldisilazane 3 with CoMe(PMe 3 ) 4 could directly provide the hydrido cobalt(III) complex CoH((C 6 H 5 )-N(SiMe 2 ) 2 )(PMe 3 ) 3 4 . Complex 4 is an analogue to complex 2 . This result indicates that a pre-coordination of the nitrogen atom in pyridine to the cobalt center before Si-H bond activation can be excluded in the formation mechanism of 2 . This exclusion is further supported by the in situ 1 H NMR spectra of the reaction mixtures between 2-pyridinetetramethyldisilazane 1 with CoMe(PMe 3 ) 4 in C 6 D 6 in different reaction times. A new bissilyl iron hydride FeH((C 5 H 4 N)-N(SiMe 2 ) 2 )(PMe 3 ) 3 ( 5 ) was obtained through the reaction of Fe(PMe 3 ) 4 with 1 . Complexes 2 , 4 and 5 with two metal-Si bonds are very stable and did not react with MeI, EtBr, acetylacetone, CO or CO 2 . The molecular structures of complexes 2 , 4 and 5 were determined by single crystal X-ray diffraction. [ABSTRACT FROM AUTHOR]

The C(carbene)N(amino)N(amine)-pincer nickel(II) bromides 1a-c were hydrogenated to the corresponding nickel(II) hydrides 2a-c by (EtO)3SiH/NaOtBu or NaBH4. These nickel(II) hydrides 2a-c were characterized by NMR and IR spectroscopy as well as X-ray diffraction. The catalytic performance of complex 2b for hydrodehalogenation reactions was explored. With a combination of 3 mol % catalyst loading, (EtO)3SiH/NaOtBu/toluene/80 °C and different reaction times, organic halides were successfully reduced to the related alkanes. A catalytic radical mechanism is proposed and partially verified by experiments. [ABSTRACT FROM AUTHOR]

The reaction of the bis(dichlorogold) complex of 2,3-bis(diphenylphosphino)maleic anhydride (L1) with S(SiMe3)2 in the presence of NaBPh4 yields the ionic dodecanuclear cluster compound [Au12(PPh2)2S4(L2)4](BPh4)2 (1). During the formation of 1, the initial ligand L1 is transformed into the doubly sylilated derivative, 3,4-bis(diphenylphosphino)-2,5-bis(trimethylsilyloxy)-furan (L2). The presence of bridging PPh2 groups is a result of the transformation of L1 in the coordination sphere of Au(i). Compound 1 was characterized by single crystal X-ray diffraction and electrospray-ionization (ESI) mass spectrometry. [ABSTRACT FROM AUTHOR]

The synthesis and reactivity of a novel iron hydride supported by [P, Se]-chelate ligand have been explored. Iron hydride o -(Ph 2 P)C 6 H 4 SeFeH(PMe 3 ) 3 ( 1 ) was obtained via the reaction of ( o -PPh 2 )PhSeH with Fe(PMe 3 ) 4 . Complex 1 reacted with HCl or acetylacetone delivered a bis-chelated iron complex ( o -(Ph 2 P)C 6 H 4 Se) 2 Fe(PMe 3 ) ( 2 ). Through the substitution reaction of PMe 3 ligand of complex 1 by CO, monocarbonyl iron(II) hydride o -(Ph 2 P)C 6 H 4 SeFeH(CO) (PMe 3 ) 2 ( 3 ) with two isomers 3A and 3B was obtained. The molecular structures of complexes 1 and 2 were determined by single crystal X-ray diffraction. [ABSTRACT FROM AUTHOR]