Search

A new family of heterometallic [FeIII2Ln] (Ln = Gd, Tb, Dy, Ho) complexes, possessing an uncommon asymmetric “V-shaped” core and interesting magnetic properties is reported.

Metal organic frameworks (MOFs) have attracted considerable attention in recent years due to their use in a wide range of environmental, industrial and biomedical applications. The employment of benzophenone-4,4'-dicarboxylic acid (bphdcH2) in MOF chemistry provided access to the 3D mixed metal MOFs [CoNa2(bphdc)2(DMF)2]n (NUIG2) and [ZnK2(bphdc)2(DMF)2]n (NUIG3), and the 2D homometallic MOF [Co2(OH)(bphdcH)2(DMF)2(H2O)2]n(OH)·DMF (1·DMF). 1·DMF is based on a dinuclear SBU and consists of interpenetrating networks with an sql topology. Dc magnetic susceptibility studies were carried out in 1·DMF and revealed the presence of weak antiferomagnetic exchange interactions between the metal centres. NUIG2 and NUIG3 are structural analogues of [ZnNa2(bphdc)2(DMF)2]n (NUIG1), which has shown an exceptionally high encapsulation for ibuprophen (Ibu), NO and metal ions. Both NUIG2 and NUIG3 display high metal ion (CoII, NiII, CuII) adsorption capacity, comparable to that of NUIG1, with NUIG2 exhibiting good performance in Ibu uptake (780 mg Ibu per g NUIG2). Monte Carlo simulations were conducted in NUIG1 in order to assess its adsorption capacity for other guest molecules, and revealed that it possesses an outstanding CO2 uptake at ambient pressure, which is larger than that of the previously reported best functioning species (104 vs. 100 cm3 (stp) per cm3). Furthermore, NUIG1 exhibits high selectivity for CO2 over CH4.

Metal-organic frameworks (MOFs) are promising multifunctional porous materials for biomedical and environmental applications. Here, we report synthesis and characterization of a new MOF based on the tetrahedral secondary building unit [Zn

Three new nanosized clusters and single molecule magnets ([Mn24] and [Mn23]) with uncommon supertetrahedral T4 – like Mn/O cores prepared from the combination of pdH2 with (py)2CO in Mn cluster chemistry are reported.

The metalloantibiotic of formula Ph2Sn(CIP)2 (CIPTIN) (HCIP = ciprofloxacin) was synthesized by reacting ciprofloxacin hydrochloride (HCIP·HCl) (an antibiotic in clinical use) with diphenyltin dichloride (Ph2SnCl2DPTD). The complex was characterized in the solid state by melting point, FT-IR, X-ray Powder Diffraction (XRPD) analysis, 119Sn Mossbauer spectroscopy, X-ray Fluorescence (XRF) spectroscopy, and Thermogravimetry/Differential Thermal Analysis (TG-DTA) and in solution by UV-Vis, 1H NMR spectroscopic techniques and Electrospray Ionisation Mass Spectrometry (ESI-MS). The crystal structure of CIPTIN and its processor HCIP was also determined by X-ray crystallography. The antibacterial activity of CIPTIN, HCIP·HCl, HCIP and DPTD was evaluated against the bacterial species Pseudomonas aeruginosa (P. aeruginosa), Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and Staphylococcus epidermidis (S. epidermidis), by the means of Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC) and Inhibition Zones (IZs). CIPTIN shows lower MIC values than those of HCIP·HCl (up to 4.2-fold), HCIP (up to 2.7-fold) or DPTD (>135-fold), towards the tested microbes. CIPTIN is classified into bactericidal agents according to MBC/MIC values. The developing IZs are 40.8 ± 1.5, 34.0 ± 0.8, 36.0 ± 1.1 and 42.7 ± 0.8 mm, respectively which classify the microbes P. aeruginosa, E. coli, S. aureus and S. epidermidis to susceptible ones to CIPTIN. These IZs are greater than the corresponding ones of HCIP·HCl by 1.1 to 1.5-fold against both the tested Gram negative and Gram positive bacteria. CIPTIN eradicates the biofilm of P. aeruginosa and S. aureus more efficiently than HCIP·HCl and HCIP. The in vitro toxicity and genotoxicity of CIPTIN were tested against human skin keratinocyte cells (HaCaT) (IC50 = 2.33 μM). CIPTIN exhibits 2 to 9-fold lower MIC values than its IC50 against HaCaT, while its genotoxic effect determined by micronucleus assay is equivalent to the corresponding ones of HCIP·HCl or HCIP.

Two new 8-connected 2-D MOFs, UCY-13 and UCY-14, based on Zr6 secondary building units (SBUs) and angular dicarboxylate ligands are reported. UCY-13 and UCY-14 display remarkable stability in various types of aqueous media, an appreciable internal surface area of 925 m2 g−1 and 678 m2 g−1, respectively, and are the first examples of 2-D MOFs investigated for their uranyl sorption capability. They exhibit exceptional UO22+ sorption capacities of 984 mg g−1 for UCY-13 and 471 mg g−1 for UCY-14 and the ability to sorb UO22+ from various types of real-world aqueous media. Both sorbents were proven to immobilize UO22+ ions, thus being unique examples of MOFs that can be potentially employed as barrier materials for environmental application. Their exceptional sorption properties are attributed to the 2-D nature and structural features directly derived from it such as the presence of several easily accessible coordination sites in the Zr6 SBUs.

The synthesis and characterization of a new family of rare earth (RE) MOFs based on a hexanuclear (RE3+)6 secondary building unit (SBU) and the angular dicarboxylic ligand 4,4′-oxybisbenzoic acid (H2OBA) with the formula {((CH3)2NH2)2[RE6(μ3-OH)8(OBA)6]}∞ (((CH3)2NH2)2(1)(RE); RE: Y, Tb, Dy, Ho) is reported. Gas sorption studies indicated a moderate Langmuir area of 377 m2 g−1. Photoluminescence studies in the visible region of the ((CH3)2NH2)2(1)(Y) doped with 5% Eu3+ or 5% Tb3+ revealed the presence of the characteristic emission bands for these RE3+ ions. Cd2+ sensing studies of ((CH3)2NH2)2(1)(Y) doped with Eu3+ however, indicated slow exchange kinetics prohibiting the use of this material for sensing applications. Successful counter ion exchange of the as synthesized compound with Na+ and Mg2+ led to the isolation of Na2(1)(Y) and Mg(1)(Y). Interestingly, the exchanged analogue Na2(1)(Y) doped with 5% Eu3+ exhibited fast Cd2+ sorption kinetics and was proven to be a greatly improved sensor for this metal ion both in terms of kinetics and sensitivity. Batch Cd2+ sorption experiments at room temperature of Na2(1)(Y) revealed a maximum sorption capacity of 63 ± 2 mg g−1 corresponding to the insertion of ∼1.25 equivalents Cd2+ per (Y3+)6 SBU. Overall this work demonstrates the post-synthetic ion exchange of the bulky ((CH3)2NH2)+ counter-ions by inorganic cations as an excellent method for the improvement of the sensing capability of RE-based anionic MOFs.

The initial employment of methyl 2-pyridyl ketoxime, (py)C(Me)NOH, in mixed metal Ni/Mn cluster chemistry, provided access to complexes [NiII2MnIII{(py)C(Me)NO}6](ClO4) (1) and [NiII2MnIII2{(py)C(Me)NO}6(OMe)2(MeOH)2](ClO4)2 (2) that display a linear and a zig-zag metal arrangement, respectively. 1 and 2 are synthesized by reacting Ni(ClO4)2·6H2O, (py)C(Me)NOH, Mn(ClO4)2·6H2O and NaOMe in different molar ratios (2:6:1:6, 1; 1:3:1:3, 2) in MeOH, and they are the first examples of 3d–3d′ mixed-metal clusters bearing (py)C(Me)NOH. The employment of phenyl 2-pyridyl ketoxime, (py)C(ph)NOH, instead of (py)C(Me)NOH, provided access to the octanuclear homometallic compound [MnII4MnIII4O4(NO3)2{(py)C(ph)NO}8(HCO2)2(MeOH)2] (3) that possesses a double-butterfly {MnII4MnIII4(μ4-O)2(μ3-O)2}12+ core. 3 joins the small family of Mn/(py)C(ph)NO− clusters. Variable-temperature, solid-state dc and ac magnetic susceptibility studies were carried out on 1 and 2 and revealed the presence of antiferromagnetic exchange interactions between the metal ions (JMn–Ni = −6.34 ± 0.14 cm−1 in 1; JMn–Ni = −4.57 ± 0.08 cm−1, JMn–Mn = −12.72 ± 0.12 in 2) and a diamagnetic ground state for both compounds.

Two new heterometallic clusters exhibiting related cores, [Mn9Ni2(μ3-Ο)10(μ3-Cl)2(O2CMe)11 (py)4(H2O)4]∙2H2O (1∙2H2O) (py = pyridine) and [Mn9Co2(μ3-Ο)10(μ3-ΟΗ)2(O2CEt)10(EtOH)3(H2O)(py)5](ClO4)2Cl (2) are reported. Compounds 1∙2H2O / 2 were prepared from reactions of [Mn3O(O2CMe)6(py)3]∙py / [Mn3O(O2CEt)6(py)3](ClO4) with MCl2∙6H2O (M = Ni2+, Co2+) and (Bun4N)MnO4 in a 1:3:0.1 / 1:1:0.1 molar ratio in MeCN (15 ml) / MeOH-EtOH (15-0.5 ml) in ∼ 28 % /

The employment of a relatively unexplored reagent, namely the Me3SiN3, in the coordination chemistry of Zn(II) and Cd(II), in the absence of any external organic chelating/bridging ligand, has led to two new, azido-bridged coordination polymers with formulae [Zn2(N3)4(MeCN)3]n (1) and [Cd3(N3)6(MeCN)2]n (2), respectively. The reaction between Zn(ClO4)2·6H2O, Me3SiN3 and NEt3 in an 1:8:2 molar ratio afforded colorless needle-like crystals of the 1-D chain 1, whereas the exact same reaction but with Cd(ClO4)2·6H2O in place of the ZnII starting material resulted in the formation of colorless needles of the 2-D polymer 2. The repeating unit of 1 consists of a [Zn4(N3)8(MeCN)6] cluster with a defective dicubane core; the vertices of the latter are occupied by the four metal ions and the bridging ligation is provided by two μ3-1,1,1 (or 3.30) and six μ-1,1 (or 2.20) end-on N3− groups. In contrast, compound 2 comprises a central [Cd4(μ3-N3)4(MeCN)4]4+ cubane-like unit, unprecedented in the coordination chemistry of CdII, which is linked to [Cd(N3)4]2− tetrahedra through μ-1,1 end-on N3− groups, eventually forming the overall layered structure of 2. Topological analysis of 2 shows a trinodal (3,4,5) network with stoichiometry (3-c)2(4-c)(5-c)2 and a very rare topological type of 3,4,5L6. Terminal ligation in both 1 and 2 is solely provided by MeCN solvate molecules. Despite the optical inactivity of complex 1, the 2-D polymer 2 exhibits an intense violet-to-blue emission upon excitation at 225 or 277 nm in the solid-state, which is tentatively ascribed to an intra-ligand fluorescence from the coordinated azido groups within the robust 2-D network. Although it is strongly evidenced that the chemistry of ZnII and CdII follows the same general trends, and thus the majority of these coordination compounds are isomorphous, the present study demonstrates the formation of two chemically, structurally and optically different compounds of divalent Group 12 metal ions, under the exact same experimental conditions. This work may pave the way to further study the chemical, structural and physicochemical properties of organic chelate-free coordination polymers and clusters using different Me3SiX (X = OCN−, SCN−, CN− and RCO2−) reagents.

Four new bismuth(III) thiosemicarbazone complexes, {BiCl3(η1-S-Hacptsc)3} (1), {[BiBr3(η1-S-Hacptsc)3]·CH3OH} (2), {[BiI2(µ2-I](η1-S-Hacptsc)]2} (3) and {[BiCl2(µ2-Cl)(η1-S-Hbztsc)2]2} (4), were prepared with the ligands acetophenone thiosemicarbazone (Hacptsc) and benzaldehyde thiosemicarbazone (Hbztsc). The complexes were characterized by a series of spectroscopic techniques. The crystal structures of 1–4 were also determined by X-ray diffraction. To the best of our knowledge, complexes 1–4 are the first examples of bismuth(III) halide aromatic thiosemicarbazones. Hirshfeld surface analysis studies show that H…H and X…H/H…X interactions of complexes 1–4 play an important role in the formation of supramolecular aggregation. Complexes 1–4 have been tested for their in vitro cytotoxic activity against human breast adenocarcinoma (MCF-7) cells. The toxicity of 1–4 has been evaluated on normal human fetal lung fibroblast cells (MRC-5). Complexes 1–4 appeared to show low cytotoxic activity and low toxicity. The antibacterial activity of 1–4 and their ligands was evaluated against the Gram negative species Pseudomonas aeruginosa (P. aeruginosa) and Escherichia coli (E. coli) and Gram positive ones Staphylococcus epidermidis (S. epidermidis) and Staphylococcus aureus (S. aureus) by the Inhibition Zone (IZ) method. The influence of 1–4 on the catalytic peroxidation of linoleic acid by the enzyme lipoxygenase (LOX) has been determined experimentally. The IC50 values reveal that the synthesized bismuth(III) aromatic thiosemicarbazone complexes have good potential to inhibit lipoxygenase, with values better than the free aromatic thiosemicarbazone ligands and cisplatin.

In recent years, the design and discovery of new metal-organic framework (MOF) platforms with distinct structural features and tunable chemical composition has remarkably enhanced by applying reticular chemistry rules and the molecular building block (MBB) approach. We targeted the synthesis of new rare earth (RE)-MOF platforms based on a rectangular-shaped 4-c linker, acting as a rigid organic MBB. Accordingly, we designed and synthesized the organic ligand 1,2,4,5-tetrakis(4-carboxyphenyl)-3,6-dimethyl-benzene (H4L), in which the two methyl groups attached to the central phenyl ring lock the four peripheral carboxyphenyl groups to an orthogonal/vertical position. We report here a new family of RE-MOFs featuring the novel inorganic building unit, RE4(μ3-O)2 (RE: Y3+, Tb3+, Dy3+, Ho3+, Er3+, and Yb3+), with planar D2h symmetry. The rigid 4-c linker, H4L, directs the in situ assembly of the unique 8-c RE4(μ3-O)2(COO)8 cluster, resulting in the formation of the first (4, 8)-c RE-MOFs with csq topology, RE-c...

The new binuclear antimony(III) complexes corresponding to the formulas [SbCl3(µ2-S)(MtMBZIM)2]2 (1), {[SbBr2(µ2-Br)(MtMBZIM)2]2·H2O} (2) and {[SbI2(µ2-I)(MtMBZIM)2]2·H2O} (3) (MtMBZIM: 5-methoxy-2-mercaptobenzimidazole) have been synthesized and structurally characterized with regard to their melting point, elemental analysis, molar conductivity, FT-IR, and FT-Raman spectroscopic techniques, and TG-DTA analysis. The crystal structures of 1-3 have been determined by single-crystal X-ray diffraction. Compounds 1-3 are doubly bridged dimers and in each square pyramidal monomeric unit, the equatorial plane is formed by two sulfur and two halogen atoms in trans-S, trans-X arrangement. The monomeric units in 2 and 3 are linked to each other via halogen bridges, but in 1, they are linked to each other via sulfur bridges; to our knowledge, this binding type is the first example of trans-S, trans-X square pyramidal antimony(III) complexes. Newly synthesized complexes with their corresponding ligand have been tested for their in vitro cytotoxic activity against human adenocarcinoma cervix (HeLa) cells as well as for their antimicrobial activity. The influence of 1-3 on the catalytic peroxidation of the linoleic acid by the enzyme lipoxygenase (LOX) has been determined experimentally and theoretically.

A series of new compounds prepared from reactions of pyridine-3,5-dicarboxylic acid (PDCH2), bipositive d-metal ions (Cd2+, Zn2+, Co2+ and Cu2+) and various template molecules [1,3-propanediol (pdH(2)), diethanolamine (deaH(3)), N-phenyldiethanolamine (phdeaH(2)), triethanolamine (teoaH(3)), 2-hydroxymethylpyridine (2hmpH), 3-hydroxymethylpyridine (3hmpH), 3-hydroxypropylpyridine (3hppH), and 4-hydroxymethylpyridine (4hmpH)] are reported. Among them, [[(CH3)(2)NH2](2)[Cd-2(PDC)(3)]](n).4nDMF.6nH(2)O, [1], [Mn(PDC)(DMF)](n), [2], [Mn-3(PDC)(2)(INA)(2)(DMF)(1.5)(H2O)(0.5)](n).nDMF.2nH(2)O, [3], and [Zn(PDC)(NMP)](n).nH(2)O, [4], are 3D coordination polymers, [Zn(PDC)(H2O)(DMF)](n), [5], [Zn(PDC)(3hmpH)](n.)nDMF.0.5nH(2)O, [6], and [Co(PDC)(3hmpH)(2)](n).0.25nDMF, [8], have 2D polymeric structures, while [Zn(PDC)(2hmpH)(2)](2).2DMF, [7], is a 0D binuclear complex, and [Cu(PDC)(3hmpH)(2)](n).0.5nDMF1.5nH(2)O, [9], is a chain polymer. Topological analysis reveals that some of the compounds display unusual structural architectures and two of them, in particular [1] and [3], present new topological types. The effect of the use of amino alcohol/polyol templates on the formation of the new compounds is also discussed in detail. The thermal stability of the prepared complexes was also studied. This study represents the initial systematic investigation on the use of a combination of polytopic nitrogen and oxygen-donor ligands and amino- or pyridine-alcohol templates for the synthesis of new MOFs.

The diamagnetic two-dimensional Hofmann-type metal-organic framework [Zn

The synthesis, structural characterization and magnetic study of novel CoII/4f and CoII/YIII clusters are described. In particular, the initial employment of di-2-pyridyl ketone, (py)2CO, in mixed metal Co/4f chemistry, provided access to four triangular clusters, [CoII2MIII{(py)2C(OEt)(O)}4(NO3)(H2O)]2[M(NO3)5](ClO4)2 (M = Gd, 1, Dy, 2, Tb, 3, Y, 4), where (py)2C(OEt)(O)&minus, is the monoanion of the hemiketal form of (py)2CO. Clusters 1&ndash, 4 are the first reported Co/4f (1&ndash, 3) and Co/Y (4) species bearing (py)2CO or its derivatives, despite the fact that over 200 metal clusters bearing this ligand have been reported so far. Variable-temperature, solid-state dc and ac magnetic susceptibility studies were carried out on 1&ndash, 4 and revealed the presence of weak ferromagnetic exchange interactions between the metal ions (JCo-Co = +1.3 and +0.40 cm&minus, 1 in 1 and 4, respectively, JCo-Gd = +0.09 cm&minus, 1 in 1). The ac susceptibility studies on 2 revealed nonzero, weak out-of-phase (&chi, &rsquo, M) signals below ~5 K.

The one-pot reaction between Mn(O2CMe)2·4H2O, salicylhydroxamic acid (shaH2) and Me4NOH·5H2O in a molar ratio of 2:1:2, and a solvent mixture comprising MeCN and MeOH, affords the new mixed-valence cluster compound (Me4N)4[MnII2MnIII9O4(O2CMe)9(shi)6] (1) in moderate yields. The anion of the tetradentate (N,O,O,O) chelating/bridging ligand shi3− resulted from the in-situ metal ion-assisted amide-iminol tautomerism of shaH2. The [MnII2MnIII9(μ3-O)4(μ-OR)3(μ3-NO)6]14+ core of 1 comprises four vertex-sharing {MnIII3(μ3-O2−)}7+ triangular subunits of different types, which are linked to each other and the MnII atoms through the oximato arms and the carboxylate O-atoms of six η1:η1:η1:η2:μ3 shi3− and three η1:η2:μ3 MeCO2− groups, respectively. Peripheral ligation about the core is provided by six η1:η1:μ MeCO2− groups and the chelating parts of the shi3− ligands. Solid-state direct-current (dc) magnetic susceptibility studies revealed the presence of predominant antiferromagnetic exchange interactions between the Mn centers, mainly promoted by the coplanarity of the μ3-O2− within the {Mn3} triangular planes and the insignificant distortion of the Mn N O Mn bridging units. Low-lying excited states precluded obtaining a good fit from the magnetization data, and the ground state was instead determined from the alternating-current (ac) data, which indicated an S = 3 ground state for 1. The combined results emphasize the continuing supply from the use of the salicylhydroxime chelating/bridging ligand of new 3d-metal clusters of very rare nuclearities and beautiful molecular structures.

Ten novel bismuth(III) halide complexes of [Bi(L)X3]n, [Bi(L)2×3]2, and [Bi(L)3×3] structural types were synthesized, in which L: 5-ethoxy-2-mercaptobenzimidazole, 5‑methoxy-2-mercaptobenzimidazole and N-methylbenzothiazole. Bismuth(III) halide complexes 1–10 were characterized by melting point, elemental analysis, molar conductivity, FT-IR, FT-Raman, UV-Visible, 1H and 13C NMR spectroscopic techniques, as well as by the Thermogravimetric-Differential Thermal Analysis (TG-DTA). The crystal structures of complexes 1–10 were determined by using single crystal X-ray diffraction study. The results show that the bismuth(III) complexes exist as monomer (4), doubly-bridged dimer (1–3 and 5–9), and edge-sharing polymer (10), in which the central bismuth atom is a six-coordinated and adopts distorted octahedral geometries. We report here, for the first time, cis-sulfur, cis-halide arrangement of the doubly-bridged dimer bismuth(III) complexes. The intermolecular interactions in bismuth(III) complexes play a very important role in the supramolecular architecture. A detailed analysis of the intermolecular interactions has been performed as based on the Hirshfeld surfaces and their associated two-dimensional fingerprint plots. Bismuth(III) halide complexes 1–10 and their free ligands have been screened for antimicrobial activity against two Gram negative bacteria (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853) and two Gram positive bacteria (Staphylococcus aureus ATCC 25923 and Enterococcus faecalis ATCC 29212). The influence of complexes 1–10 and the free ligands on the catalytic peroxidation of the linoleic acid by the enzyme lipoxygenase (LOX) has been determined experimentally and theoretically.

The synthesis and characterization of {[Co5(INA)3(HCOO)7(DMF)(H2O)]·2DMF·4H2O}∞ (INA– = the anion of isonicotinic acid) denoted as Co5‐INA·2DMF·4H2O is reported. The compound was isolated from the reaction of Co(NO3)2·6H2O with HINA in the presence of HCOOH in N,N‐dimethylformamide (DMF) at 100 °C. It exhibits a rigid 3‐D porous structure based on Co5 repeating units which are linked through carboxylate ligands (from HCOO– and INA–) to form an infinite rod‐shaped secondary building unit (SBU). The rods are connected through isonicotinate ligands to produce a unique (3,3,4,4,4‐coordinated) 5‐nodal 3D network with point symbol (4.5.6.72.9)(4.5.62.7.8)(4.5.7)2(5.62.73). Gas sorption studies revealed that Co5‐INA displays a microporous structure with BET area 264.5 m2 g–1 and CO2 uptake of 1.96/1.29 mmol·g–1 at 273/298 K (1 bar), respectively. Magnetism studies revealed that Co5‐INA displays spin canting behavior with a spin glass relaxation process at ca. 5.0 K.

Stefania Tanase and Anastasios J. Tasiopoulos introduce the Molecular Systems Design & Engineering themed collection on molecular systems for sensing.

Three new antimony(III) iodide complexes with the N,N-diethylcarbamodithioic acid of formulae {[(SbI(Et2DTC)2)(I2)]n} (1), {[(Sb(Et2DTC)2)4 (SbI6) (I3)]n} (2) and {[SbI(Et2DTC)2]2} (3), (Et2DTCH: N,N-diethylcarbamodithioic acid, C5H11NS2) were synthesized from the reaction of antimony(III) iodide with tetraethylthiuram disulfide in 1:1 stoichiometry. The complexes 1–3 were characterized by melting point, elemental analysis, FT-IR spectroscopy, Raman spectroscopy, 1H, 13C NMR spectroscopy and Thermal Gravimetry–Differential Thermal Analysis (TG–DTA). Moreover, crystal structures of complexes 1–3 were determinated with single crystal X-ray diffraction analysis. Complexes 1–3 derived from ligand reduction with concomitant degradation of the tetraethylthiuram disulfide to dithiocarbamates. Complexes 1 and 2 are polymer but complex 3 is dimmer. Complex 1 consists of two residues, [SbI(Et2DTC)2] and [I2], while 2 consists of three residues, four cationic [Sb(Et2dtc)2]+, one [SbI6]3− and one [I3]− counter anion. Complexes 1–3 were evaluated for their in vitro cytotoxic activity against human breast adenocarcinoma (MCF-7) and human cervix adenocarcinoma (HeLa) cells. Structure Activity Relationship (SAR) studies reveal that the high activity of the complexes is positively correlated with the low H-all atoms intermolecular contacts.

Five new bismuth(III) halide compounds (BiX3, X = Br or I) of formulae {[BiBr(Me2DTC)2]n} (1), {[BiBr2(Et2DTC)]n} (2), {[BiI2(Me2DTC)]n} (3), {[BiI(Et2DTC)2]n} (4) and {[BiI(μ2-I)(Et2DTC)2]2}n (5) (Me2DTCH = dimethyldithiocarbamate, C3H7NS2 and Et2DTCH = diethyldithiocarbamate, C5H11NS2) were synthesized from the reactions between bismuth(III) bromide (BiBr3) or bismuth(III) iodide (BiI3) with tetramethylthiuram monosulfide (Me4tms), tetramethylthiuram disulfide (Me4tds) or tetraethylthiuram disulfide (Et4tds). The complexes were characterized by melting point, elemental analysis, FT-IR spectroscopy, Raman spectroscopy, 1H, 13C NMR spectroscopy and Thermal Gravimetry-Differential Thermal Analysis (TG-DTA). Moreover, the crystal structures of 1–5 were determined with single crystal X-ray diffraction analysis. The ligands of compounds 1–5 were derived from reduction with concomitant degradation to dithiocarbamates. Complexes 1–4 are polymers, whereas complex 5 is a dimer, built up from monomeric units with square pyramidal (SP) geometry (1, 4 and 5) and pentagonal bipyramidal geometry (2 and 3) around the bismuth center. Complexes 1–5 were evaluated for their in vitro cytotoxic activity against human adenocarcinoma breast (MCF-7) and cervix (HeLa) cells. The toxicity on normal human fetal lung fibroblast cells (MRC-5) is also evaluated. Since estrogen receptors (ERs) are located in MCF-7, in contrast to HeLa cells, the estrogenic effect of 1–5 on MCF-7 cells was studied by means of a methylene blue assay. Hirshfeld surface volumes were analyzed to clarify the nature of the intermolecular interactions. Molecules with lower H-all atoms inter-molecular interactions tend to exhibit higher activity against both MCF-7 and HeLa cells. Structure–activity relationship (SAR) studies were performed for these complexes using 2D topological based disparity analysis. This finding underlines the significance of the halogen atoms in the coordination sphere of the metal ion.

The initial use of ligands 2'-hydroxyacetophenone (HL

A novel hexameric [MnNa

Novel silver(I) metallo-drugs of the nonsteroidal anti-inflammatory drug nimesulide (nim) and the mitochondriotropic triaryl derivatives of pnictogen ligands (tpE, E = P (tpp, tptp, or totp), As (tpAs), Sb (tpSb)) with the formulas {[Ag(nim) (tpp)2]DMF} (1), [Ag(nim) (tptp)2] (2), [Ag(nim) (totp)] (3), [Ag(nim) (tpAs)2] (4), and [Ag(nim) (tpSb)3] (5) ((tpp = triphenyphosphine, tptp = tri(p-tolyl)phosphine, totp = tri(o-tolyl)phosphine, tpAs = triphenylarsine, tpSb = triphenylantimony, and DMF = dimethylformamide) were synthesized and characterized by melting point, vibrational spectroscopy (mid-Fourier transform IR), (1)H NMR, UV-visible spectroscopic techniques, and X-ray crystallography. The in vitro cytotoxic activity of 1-5 against human breast adenocarcinoma cancer cell lines: MCF-7 (estrogen receptor (ER) positive) and MDA-MB-231 (ER negative) was determined. The genotoxicity on normal human fetal lung fibroblast cells (MRC-5) caused by 1-5 was evaluated by fluorescence microscopy. The absence of micronucleus in MRC-5 cells confirms the in vitro non toxicity behavior of the compounds. Because of the morphology of the cells, an apoptotic pathway was concluded for the cell death. The apoptotic pathway, especially though the mitochondrion damage, was confirmed by DNA fragmentation, cell cycle arrest, and permeabilization of the mitochondrial membrane tests. The molecular mechanism of action of 1-5 was further studied by (i) the binding affinity of 1-5 toward the calf thymus (CT) DNA, (ii) the inhibitory activity of 1-5 against lipoxygenase (an enzyme that oxidizes polyunsaturated fatty acids to leukotrienes or prostaglandins), and (iii) the catalytic activity of 1-5 on the oxidation of linoleic acid (an acid that partakes in membrane fluidity, membrane enzyme activities, etc.) to hyperoxolinoleic acid by oxygen.

The missing VIV11VV7 oxidation-state member of the polyoxooctadecavanadate(IV/V) — azide family of inorganic host-guest systems has been incorporated in a NaI-containing 3D architecture; the complex shows remarkable inhibition properties on human platelet aggregation and antitumoural activity against cancer cell lines.

In this review, aspects of the syntheses, structures and magnetic properties of giant 3d and 3d/4f paramagnetic metal clusters in moderate oxidation states are discussed. The term "giant clusters" is used herein to denote metal clusters with nuclearity of 30 or greater. Many synthetic strategies towards such species have been developed and are discussed in this paper. Attempts are made to categorize some of the most successful methods to giant clusters, but it will be pointed out that the characteristics of the crystal structures of such compounds including nuclearity, shape, architecture, etc. are unpredictable depending on the specific structural features of the included organic ligands, reaction conditions and other factors. The majority of the described compounds in this review are of special interest not only for their fascinating nanosized structures but also because they sometimes display interesting magnetic phenomena, such as ferromagnetic exchange interactions, large ground state spin values, single-molecule magnetism behaviour or impressively large magnetocaloric effects. In addition, they often possess the properties of both the quantum and the classical world, and thus their systematic study offers the potential for the discovery of new physical phenomena, as well as a better understanding of the existing ones. The research field of giant clusters is under continuous evolution and their intriguing structural characteristics and magnetism properties that attract the interest of synthetic Inorganic Chemists promise a brilliant future for this class of compounds.

A convenient route has been developed for the formation of [ Ο(OMe)6(η5-C5H5)3](I3) (2) involving methanolysis (and possibly hydrolysis) of species derived from titanocene diiodide, [TiIV(η5-C5H5)2I2] (1), under aerobic conditions. Single-crystal X-ray crystallography reveals that the cation of 2 consists of three TiIV's in a triangular arrangement bridged by a central μ3-oxide; the latter lies 0.686 A out of the Ti3 plane. Each edge of the triangle is bridged by oxygen of η1 : μ-MeO−. Terminal ligation is provided by three methoxide and three cyclopentadienyl groups. All TiIV centers are five-coordinate in an extremely distorted geometry. IR and electronic data are discussed in terms of the known structure and coordination modes of O2−, MeO−, and η5-C5 . A proposal for the mechanism of the unexpected formation of the triiodide ( ) counteranion that is present in the crystal structure of 2 is also provided.

A new Cu2+ complex that was isolated from the initial use of 5-((pyridin-4-ylmethylene) amino) isophthalic acid (PEIPH2) in 3d metal-organic framework (MOF) chemistry is reported. Complex [Cu-3(PEIP)(2)(5-NH2-mBDC)(DMF)].7DMF8 denoted as Cu-PEIP.7DMF was isolated from the reaction of Cu(NO3)(2).2.5H(2)O with PEIPH2 in N, N-dimethylformamide (DMF) at 100 degrees C and contains both the PEIP2-ligand and its 5-NH2-mBDC(2)-fragment. After the structure and properties of Cu-PEIP were known an analogous complex was prepared by a rational synthetic method that involved the reaction of Cu(NO3)(2).2.5H(2)O, 5-((pyridin-4-ylmethyl) amino) isophthalic acid (PIPH2 - the reduced analogue of PEIPH2) and 5-NH2-mBDCH(2) in DMF at 100 degrees C. Cu-PEIP comprises two paddle-wheel [Cu-2(COO)(4)] units and exhibits a 3D-framework with a unique trinodal underlying network and point symbol (4.52)(4)(4(2).5(4).6(4).8(3).9(2))(2)(5(2).8(4)). This network consists of pillared kgm-a layers containing a hexagonal shaped cavity with a relatively large diameter of similar to 8-9 angstrom surrounded by six trigonal shaped ones with a smaller diameter of similar to 4-5 angstrom and thus resembles the structure of HKUST-1. Gas sorption studies revealed that Cu-PEIP exhibits a 1785 m(2) g(-1) BET area as well as high CO2 sorption capacity (4.75 mmol g(-1) at 273 K) and CO2/CH4 selectivity (8.5 at zero coverage and 273 K).

Attempts to isolate the (Ph3P)2Pt complex of the highly pyramidalized olefin 3,7-dimethyltricyclo[3.3.0.03,7]oct-1(5)-ene 2 by generation of 2 in the presence of (Ph3P)2PtC2H4, followed by crystallization of the complex (2-Pt) from THF−ethanol, resulted in the isolation of the adduct of 2-Pt with ethanol (5). Calculations confirm that addition of alcohol across the C1−C5 bond is more favorable in 2-Pt than in the corresponding (Ph3P)2Pt complexes of less pyramidalized olefins, despite the stronger Pt−C bonds in 2-Pt.

The use of 4-(hydroxymethyl)pyridine (4hmpH) and pyrimidine (pym) in manganese benzoate chemistry has been investigated. The reactions of 4hmpH and pym with Mn(O2CPh)2 · 2H2O in MeCN affords the complexes [Mn6O2(O2CPh)10(4hmpH)3 (MeCN)] (1) and [Mn6O2(O2CPh)10(pym)2(MeCN)2] (2), respectively. Complex 1 contains a {Mn6O2}10+ core that can be conveniently described as two edge-sharing Mn4 tetrahedra at the center of each of which is a μ4-O2− ion. Peripheral ligation to the octahedrally coordinated Mn centres is provided by 10 bridging PhCO 2 - ligands, three N-monodentate ligands and one terminal MeCN group. The complex is mixed-valence ( Mn 4 II Mn 2 III ) and the MnIII ions are assigned as the two central metal centres bridged by two O2− ions. The molecular structure of 2 is very similar to that of 1, except that the terminal ligands are two monodentate pym molecules and two MeCN groups. IR data are discussed in terms of the nature of bonding and the known structures. Complexes 1 and 2 were characterized by variable-temperature ac and dc magnetic susceptibility data and found to possess a total spin ground state of 0. The ST = 0 ground state is explained in terms of the strong antiferromagnetic coupling within the central Mn 2 III O 2 unit.

The synthesis and characterization of [Co-9(INA)(18)(H2O)(6)]center dot 11DMF center dot 15H(2)O(8) (Co-9-INA center dot 11DMF center dot 15H(2)O) (INA(-) = the anion of isonicotinic acid) is reported. It exhibits a rigid 3D-porous structure with a Co-9 repeating unit consisting of four [Co-2(II)(mu-O2CR)(2)(mu-H2O)] subunits (two unique) linked through bridging INA(-) ligands to an isolated Co-II ion (half unique). The [Co-2(II)] dimers and the isolated Co-II ion have assembled to create a trinodal (6,7,8)-coordinated network with point symbol (3(2).4(11).5(6).6(2))(2)(3(2).4(18).5(4).6(4))(2)(3(4).4(4).5(4).6(3)). Gas sorption studies revealed that Co-9-INA exhibits 910 m(2) g(-1) BET area, 4.2 mmol g(-1) CO2 uptake at 273 K/1 bar, and 6.7 CO2/CH4 selectivity at zero coverage. Furthermore, Co-9-INA displays capability for exchange of the guest solvent molecules by various organic molecules in a single-crystal to single-crystal fashion. Direct and alternating current magnetic susceptibility studies revealed the existence of dominant antiferromagnetic interactions between the Co2+ ions that result in a paramagnetic ST = 3/2 spin ground state value. Overall, this work emphasizes the potential of relatively simple and inexpensive polytopic ligands, such as isonicotic acid, to stabilize microporous MOFs with significant CO2 sorption capacity.

The initial employment of alpha-benzoin oxime (bzoxH(2)) in higher oxidation state 3d metal cluster chemistry has provided access to a new enneanuclear Mn(III) complex with an unprecedented metal-core topology consisting of two triangular [Mn(3)(mu(3)-Omicron(2-))(mu-OmicronNu)(3)](4+) fragments connected by a linear [Mn(3)(mu-OmicronNu)(6)](3+) unit. The Mn(III)(9) cluster is antiferromagnetically coupled and has an S = 3 spin ground state.

A 1-D coordination polymer, constructed using a combination of diols and phenolic oximes, contains a novel [Mn-9] sub-unit, a nanosized [Mn-40] octagonal super-structure and a [Mn-21] repeating unit.

A series of new Zn2+-trimesate (btc(3-)) metal organic frameworks (MOFs) has been isolated in the presence of various amino-alcohols under solvothermal conditions. Thus, the reaction of ZnCl2 with trimesic acid (H(3)btc) and the amino alcohols triethanolamine (teoa), 2(hydroxymethyl)piperidine (hmpip), N-tert-butyldiethanolamine (tbdeoa), 1,4-bis(2-hydroxyethyl)piperazine (bhep), N-methyldiethanolamine (mdeoa), or 4-(2-hydroxyethyl)morpholine (hem) in a 1.6:1:5.6 molar ratio in DMF afforded compounds (teoaH)(2)[Zn(btc)(1.33)] (MOAAF-1) (MOAAF = metal organic amino-alcohol framework), (NH2Me2)(2)(hmpipH)[Zn-3(btc)(3)] (MOAAF-2), (NH2Me2)-(tbdmaH)(2)[Zn-3(btc)(3)] (MOAAF-3) (tbdma = N-tert-butyl-dimethylamine), (NH2Me2)(bhepH(2))[Zn-3(btc)(3)] (MOAAF-4), (NH2Me2) [Zn-4(btc)(3)(mdeoa)(2)] (MOAAF-5), and (NH2Me2)[Zn-4(btc)(3)(hem)(2)] (MOAAF-6), respectively. The compounds display 3D structures with relatively large cavities (4-10 angstrom) and high potential solvent-accessible areas (38-68% of the unit cell volumes). A number of novel structural features are revealed in the reported MOFs, such as unprecedented dinuclear [Zn-2(COO)(5)](-1) secondary building units (SBUs) and unique network topologies (e.g., in compounds MOAAF-2, MOAAF-3, MOAAF-5, and MOAAF-6). The amino-alcohols employed played a key role for the appearance of such novel structural features in MOAAF 1-6 since they were found to act as bases responsible for the deprotonation of H(3)btc, templates, and chelating ligands. Specifically, most of the compounds synthesized were shown to be templated by protonated amino alcohols that are involved in hydrogen bonding interactions with the frameworks, whereas in two cases (compounds MOAAF-5 and MOAAF-6) the amino alcohols acted as chelating ligands affecting significantly the underline topology of the MOFs. The thermal stability and photoluminescence properties of the MOFs are also discussed. This work represents the initial systematic investigation on the use of combination of amino alcohols and polycarboxylate ligands for the synthesis of new MOFs, demonstrating it as a powerful synthetic strategy for the isolation of novel MOFs.

A new flexible Cd2+ metal organic framework (MOF), denoted as UCY-3, which is the second example of a MOF with the ligand H3CIP [H3CIP = 5-(4-carboxybenzylideneamino)isophthalic acid], is reported. It shows a unique (3,3,6)-connected topology and is based on a neutral non-oxo triangular [Cd-3(COO)(6)] secondary building unit that appears for the first time in MOFs chemistry. UCY-3 displays significant structural flexibility, capability for exchange of the guest solvents by various organic molecules in a single-crystal-to-single-crystal fashion as well as breathing capacity allowing the incorporation of relatively large amount of benzene into its pores. Overall this work indicates that MOFs based on semi-rigid polytopic ligands may adopt unprecedented structural types and exhibit unexpectedly high absorption capacities for relatively bulky organic molecules, as a result of their flexibility and breathing capability.

Single-crystal-to-single-crystal (SCSC) transformations represent some of the most fascinating phenomena in chemistry. They are not only intriguing from a basic science point of view but also provide a means to modify or tune the properties of the materials via the postsynthetic introduction of suitable guest molecules or organic functional groups into their structures. Here, we describe UCY-2, a new flexible Nd3+ metal-organic framework (MOF), which exhibits a unique capability to undergo a plethora of SCSC transformations with some of them being very uncommon. These structural alterations involve the replacement of coordinating solvent molecules of UCY-2 by terminally ligating solvents and organic ligands with multiple functional groups including -OH, -SH, -NH-, and -NH2 or their combinations, chelating ligands, anions, and two different organic compounds. The SCSC coordinating solvent exchange is thus demonstrated as a powerful method for the functionalization of MOFs.