Phthalocyaninate und Tetraphenylporphyrinate von hochkoordiniertem ZrIV/HfIV mit Hydroxo‐, Chloro‐, (Di)Phenolato‐, (Hydrogen)Carbonato‐ sowie (Amino)Carboxylato‐Liganden

Phthalocyaninates and Tetraphenylporphyrinates of High Co‐ordinated Zr^IV/Hf^IV with Hydroxo, Chloro, (Di)Phenolato, (Hydrogen)Carbonato, and (Amino)Carboxylato Ligands Crystals of tetra(n‐butyl)ammonium cis‐tri(phenolato)phthalocyaninato(2‐)zirconate(IV) ( 2 ) and ‐hafnate(IV) ( 1 ), di(tetra(n‐butyl)ammonium) cis‐di(tetrachlorocatecholato(O, O')phthalocyaninato(2‐)zirconate(IV) ( 3 ), and cis‐(di(μ‐alaninato(O, O')di(μ‐hydroxo))di(phthalocyaninato(2‐)zirconium(IV)) ( 12 ) have been isolated from tetra(n‐butyl)ammonium hydroxide solutions of cis‐di(chloro)phthalocyaninato(2‐)zirconium(IV) and ‐hafnium(IV), respectively, and the corresponding acid in polar organic solvents. Similarly, with cis‐di(chloro)tetraphenylporphyrinato(2‐)zirconium(IV), ^cis[Zr(Cl)₂tpp] as precursor crystalline tetra(n‐butyl)ammoniumcis‐tetrachlorocatecholato(O, O')hydrogentetrachlorocatecholato(O)tetraphenylporphyrinato(2‐)zirconate(IV) ( 4 ), cis‐hydrogencarbonato(O, O')phenolatotetraphenylporphyrinato(2‐)zirconium(IV) ( 6 ), cis‐di(benzoato(O, O'))tetraphenylporphyrinato(2‐)zirconium(IV) ( 11 ), and cis‐tetra(μ‐hydroxo)di(tetraphenylporphyrinato(2‐)zirconium(IV)) ( 13 ) with a cis‐arrangement of the symmetry equivalent μ‐hydroxo ligands, and from di(acetato)tetraphenylporphyrinato(2‐)zirconium(IV) the corresponding trans‐isomer ( 14 ) have been prepared. The endothermic dehydration at 215 °C of 13/14 yields μ‐oxodi(μ‐hydroxo)di(tetraphenylporphyrinato(2‐)zirconium(IV)) ( 15 ). 15 also precipitates on dilution of a solution of ^cis[Zr(X)₂tpp] (X = Cl, OAc) in dmf/(ⁿBu₄N)OH with water, while on prolonged standing of this solution on air tri(tetra(n‐butyl)ammonium) cis‐(^nido〈di(carbonato(O, O'))undecaaquamethoxide〉tetraphenylporphyrinato(2‐)zirconate(IV) ( 7 ) crystallizes, in which Zr^IV coordinates a supramolecular nestlike ^nido〈(O₂CO)₂(H₂O)₁₁OCH₃〉^5— cluster anion stabilised by hydrogen bonding in a nanocage of surrounding (ⁿBu₄N)⁺ cations. On the other hand, ^cis[Zr(Cl)₂pc] forms with (Et₄N)₂CO₃ in dichloromethane di(tetraethylammonium) cis‐di(carbonato(O, O')phthalocyaninato(2‐)zirconate(IV) ( 5 ). ^cis[Zr(Cl)₂tpp] dissolves in various O‐donor solvents, from which cis‐di(chloro)dimethylformamidetetraphenylporphyrinato(2‐)zirconium(IV) ( 8 ), cis‐di(chloro)dimethylsulfoxidetetraphenylporphyrinato(2‐)zirconium(IV) ( 9 ), and a 1:1 mixture ( 10 ) of cis‐di(chloro)dimethylsulfoxidetetraphenylporphyrinato(2‐)zirconium(IV) ( 10a ) and cis‐chlorodi(dimethylsulfoxide)tetraphenylporphyrinato(2‐)zirconium(IV) chloride ( 10b ) crystallize. All complexes contain solvate molecules in the solid state, except 3 . Zr^IV/Hf^IV is directed by ∼1Å out of the plane of the tetrapyrrolic ligand (pc, tpp) towards the mutually cis‐coordinated axial ligands. In the more concavely distorted phthalocyaninates, Zr^IV is mainly eight‐coordinated and in the tetraphenylporphyrinates seven‐coordinated. The octa‐coordinated Zr atom is in a distorted quadratic antiprism, and the hepta‐coordinated one is in a square‐base‐trigonal‐cap cooordination polyhedron. In most tpp complexes, the Zr atom is displaced by up to 0.3Å out of the centre of the coordination polyhedron towards the tetrapyrrolic ligand. In 13/14 , both antiprisms are face shared by an O₄ plane, and in 12 they are shared by an O₂ edge and the O atoms of the bridging aminocarboxylates, the dihedral angle between the O₄ planes of both antiprisms being 50.1(1)°. The mean Zr‐N_p distance is 0.05Å longer in the pc complexes than in the tpp complexes (d(Zr‐N_p)_pc = 2.31Å). In the monophenolato complexes, the mean Zr‐O distance (∼2.00Å) is shorter than in the complexes with other O‐donor ligands (d(Zr‐O)_pc = 2.18Å; d(Zr‐O)_tpp = 2.21Å); the Zr‐Cl distances vary between 2.473(1) and 2.559(2)Å (d(Zr‐Cl)_tpp = 2.51Å). d(C‐O_exo) = 1.494(4)Å in the bidentate hydrogencarbonato ligand in 6 is 0.26Å longer than in the bidentate carbonato ligands in 5 and 7 . 9 and 10a are rotamers slightly differing by the orientation of the axial ligands with respect to the tpp ligand. In 1—4, 6 , and 11 the phenolato, catecholato, and benzoato ligands, respectively, are in syn‐ and/or anti‐conformations with respect to the plane of the macrocycle. π‐Dimers with modest overlap of the neighbouring macrocyclic rings are observed in 5, 6, 8, 9, 10b, 12 , and 14 . The common UV/Vis spectroscopical and vibrational properties of the new phthalocyaninates and tetraphenylporphyrinates scarcely reflect their rich structural diversity.     

Green synthesis approach for novel benzenesulfonamide nanometer complexes with elaborated spectral,theoretical and biological treatments

New series of nano‐sized bi‐homonuclear Ce (III), ZrO (II), Sn (II), Pb (II), Cr (III), Fe (III) and Cu (II) complexes with 4‐[(2,4‐dihydroxybenzylidene)amino]‐N‐(1,3‐thiazol‐2‐yl) benzenesulfonamide (H₃L) were synthesized via green solid‐state method. The structural and molecular formulae of all synthesized complexes were established based on variable spectral, analytical and theoretical implementations. FT‐IR study confirms the coordination of H₃L with metal ions through the Schiff base and sulfonamide centers in di‐basic tetra‐dentate mode. Thermal analysis, magnetic moment and electronic spectra are attributing to octahedral configuration around Ce (III), Cr (III) and Fe (III) centers, while with ZrO (II), Sn (II), Pb (II) and Cu (II) centers, acquired tetrahedral arrangement. TEM and XRD studies, represent the nanometer characters of most metal ion complexes. TGA curves are utilized to compute the activation thermo‐kinetic parameters over different decomposition stages applying Coats‐Redfern method. Theoretical implementation executed by Gaussian09 program exerted the structures for the best atomic orientation over whole molecules. QSAR data were achieved over Hyper Chem 8.1 program through molecular mechanics process. Docking complexes between free ligand and different protein receptors were obtained through AutoDock Tools 4.2. Antimicrobial, antifungal and antitumor activities of the metal complexes were studied in comparing with free ligand to assert their potential therapeutic uses. H₃L, Ce (III), Fe (III) and Cu (II) complexes displayed high antibacterial activity near that of standard Gentamycin. Moreover, Cr (III) complex displayed highest cytotoxicity against human liver Carcinoma cell line (HEPG2).     

Reactivity of substituted copper(II) salicylates with tert‐butylperoxyl radical: Structure–reactivity relationships

Absolute rate constants (k_eff) for the chemical reactions of Cu(II)₂(3,5‐di‐iso‐propylsalicylate)₄(H₂O)₃, Cu(II)₂(3,5‐di‐tert‐butylsalicylate)₄, Cu(II)₂(3,5‐di‐tert‐butylsalicylate)₄(H₂O)₄, Cu(II)₂(3,5‐dimethylsalicylate)₄(H₂O)₃, Cu(II)₂(3‐ethylsalicylate)₄(H₂O), Cu(II)₂(3‐phenylsalicylate)₄, and Cu(II)(3,5‐di‐iso‐propylsalicylate)₂(pyridine)₂ with tert‐butylperoxyl radical were determined using kinetic electron paramagnetic resonance measurements in 10% toluene in the hexane medium at temperatures ranging from ?63°C to 2°C. These antioxidant (AO) chelates were ranked by their reactivity as follows: 2,6‐di‐tert‐butyl‐4‐methylphenol ? Cu(II)₂(3,5‐di‐tert‐butylsalicylate)₄ ? Cu(II)₂(3‐phenylsalicylate)₄ > Cu(II)₂(3,5‐di‐iso‐propylsalicylate)₄(H₂O)₃ ? Cu(II)₂(3,5‐di‐tert‐butylsalicylate)₄(H₂O)₄ ? Cu(II)₂(3,5‐dimethylsalicylate)₄(H₂O)₃ > Cu(II)₂(3‐ethylsalicylate)₄(H₂O) ? Cu(II)(3,5‐di‐iso‐propylsalicylate)₂(pyridine)₂ at 20°C. Differential pulse voltammetry was used to determine redox behavior of these chelates in CH₂Cl₂. Two types of salicylic OH groups were detected in these Cu(II) salicylates, characterized by the presence or absence of AO reactivity. One of them was coordinate covalently bonded to Cu(II) via the oxygen atoms of the salicylic OH groups, displaying oxidation peak potentials in the range from +650 to 970 mV versus Ag/Ag⁺. The second type was intramolecularly hydrogen bonded to carboxylate oxygens, with an oxidation peak potential in the range from +1100 to 1200 mV versus Ag/Ag⁺. It was concluded that non–hydrogen‐bonded salicylic OH groups are responsible for the antiperoxyl radical reactivity of these chelates, while neither Cu(II) nor salicylate ligands displayed reactivity with peroxyl radical. It has been established in this research that axially bonded electron pair donors such as pyridine and water decrease H‐donating reactivity of Cu(II) salicylates by promoting the formation of intramolecular hydrogen bonding between the salicylic OH hydrogen atoms and carboxylate oxygen atoms in the salicylic ligands. Dependences of log k_eff at 20°C and the anodic oxidation potential (E_pa) for the salicylic OH group on the difference between symmetric and asymmetric stretching frequencies of carboxylate groups (in Fourier transform infrared spectra) for the substituted Cu(II) salicylates were determined. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 42: 56–67, 2010     

Synthesis,Structure, and Photophysical Properties of the Di‐ and Trinuclear Phosphine‐Diimine Complexes of Copper(I)

Reactions of [Cu(NCMe)₄]⁺ with stoichiometric amount of diphosphine R₂P–(C₆H₄)_n–PR₂, (R = NC₄H₄, n = 1; R = Ph, n = 1, 2, 3) or tri‐phosphine 1, 3, 5‐(PPh₂–C₆H₄–)₃–C₆H₃ ligands give the corresponding di‐ or trinuclear copper(I) acetonitrile‐phosphine complexes 1 – 5 . Substitution of the labile acetonitrile groups with chelating aromatic diimines – 2, 2′‐bipyridine (bpy), 1, 10‐phenanthroline (phen), 5, 6‐dimethyl‐1, 10‐phenanthroline (dmp), 5, 6‐dibromo‐1, 10‐phenanthroline (phenBr₂) – gives the corresponding substituted compounds 6 – 16 . In all complexes 1 – 16 each central Cu^I atom has tetrahedral configuration completed with two N‐ and two P‐donor groups. The compounds obtained were characterized using elemental analysis, ESI‐MS, X‐ray crystallography, and NMR spectroscopy. All phosphine‐diimine compounds 6 – 16 are photoluminescent at room temperature both in dichloromethane solution and in solid state (λ_ex = 385 nm). In CH₂Cl₂ solution the maxima of emission bands are found in a range 540–640 nm, and in solid in a similar range 538–620 nm. Emission of 6 – 16 is assigned to the triplet excited state dominated by the charge transfer transitions with contribution of the MLCT character.     

Das erste Oxatetraphospholan, (PBut)4O

Contributions to the Chemistry of Phosphorus. 244. The First Oxatetraphospholane, (PBu^t)₄O Under suitable conditions, the reaction ot tri‐tertbutylcyclotriphosphane, (PBu^t)₃, with di‐tert‐butylperoxide gives rise to a mixture of 2,3,4,5‐tetra‐tert‐butyl‐1,2,3,4,5‐oxatetraphospholane, (PBu^t)₄O ( 1 ), and 1,2‐di‐tert‐butyl‐1,2‐di‐tert‐butoxidiphosphane, [Bu^t(Bu^tO)P]₂ ( 2 ). Both compounds have been isolated in the pure state. The oxatetraphospholane 1 is a constitutional isomer of 1,2,3,4‐Tetra‐tert‐butyl‐1‐oxocyclotetraphosphane, which has been reported recently [1]. The corresponding reaction of tetra‐tert‐butylcyclotetraphosphane furnishes only small amounts of 1 because of the kinetic stability of (PBu^t)₄. The diphosphane 2 is presumably a secondary product of primarily formed oxocyclotetraphosphanes (PBu^t)₄O_1–4. The NMR parameters of 1 and 2 are reported and discussed.     

(2‐Methyl­quinolin‐8‐olato)­iron(III) and ‐copper(II) complexes

The crystal structures of tris(2‐methyl­quinolin‐8‐olato‐N,O)­iron(III), [Fe­(C₁₀­H₈­NO)₃], (I), and aqua­bis(2‐methyl­quinolin‐8‐olato‐N,O)­copper(II), [Cu­(C₁₀­H₈NO)₂­(H₂O)], (II), have been determined. Compound (I) has a distorted octahedral configuration, in which the central Fe atom is coordinated by three N atoms and three O atoms from three 2‐methylquinolin‐8‐olate ligands. The three Fe—O bond distances are in the range 1.934 (2)–1.947 (2) Å, while the three Fe—N bond distances range from 2.204 (2) to 2.405 (2) Å. In compound (II), the central Cu^II atom and H₂O group lie on the crystallographic twofold axis and the coordination geometry of the Cu^II atom is close to trigonal bipyramidal, with the three O atoms in the basal plane and the two N atoms in apical positions. The Cu—N bond length is 2.018 (5) Å. The Cu—O bond length in the basal positions is 1.991 (4) Å, while the Cu—O bond length in the apical position is 2.273 (6) Å. There is an intermolecular OW—H?O hydrogen bond which links the mol­ecules into a linear chain along the b axis.     

{nBuMg(OR)}2 und {Mg(OR)2}2 (R = 2, 4, 6‐tBu3C6H2) – sterisch überfrachtete Magnesiumalkoholate

Reaction of 2, 4, 6‐tri‐tert‐butylphenol ( 1 ) with di‐n‐butylmagnesium in the molar ratio 1:1 allows the synthesis of {(nBu)Mg(μ‐OR)₂Mg(nBu)} ( 2 ) (R = 2, 4, 6‐tBu₃C₆H₂), which reacts with excess 1 to give the homoleptic alcoholate complex {(RO)Mg(μ‐OR)₂Mg(OR)} ( 3 ) (R = 2, 4, 6‐tBu₃C₆H₂). The structures of 2 and 3 were determined by X‐ray crystallography.     

Unusual 4‐arsonoanilinium cationic species in the hydrochloride salt of (4‐aminophenyl)arsonic acid and formed in the reaction of the acid with copper(II) sulfate,copper(II) chloride and cadmium chloride

Structures having the unusual protonated 4‐arsonoanilinium species, namely in the hydrochloride salt, C₆H₉AsNO₃⁺·Cl⁻, (I), and the complex salts formed from the reaction of (4‐aminophenyl)arsonic acid (p‐arsanilic acid) with copper(II) sulfate, i.e. hexaaquacopper(II) bis(4‐arsonoanilinium) disulfate dihydrate, (C₆H₉AsNO₃)₂[Cu(H₂O)₆](SO₄)₂·2H₂O, (II), with copper(II) chloride, i.e. poly[bis(4‐arsonoanilinium) [tetra‐μ‐chlorido‐cuprate(II)]], {(C₆H₉AsNO₃)₂[CuCl₄]}_n , (III), and with cadmium chloride, i.e. poly[bis(4‐arsonoanilinium) [tetra‐μ‐chlorido‐cadmate(II)]], {(C₆H₉AsNO₃)₂[CdCl₄]}_n , (IV), have been determined. In (II), the two 4‐arsonoanilinium cations are accompanied by [Cu(H₂O)₆]²⁺ cations with sulfate anions. In the isotypic complex salts (III) and (IV), they act as counter‐cations to the {[CuCl₄]²⁻}_n or {[CdCl₄]²⁻}_n anionic polymer sheets, respectively. In (II), the [Cu(H₂O)₆]²⁺ ion sits on a crystallographic centre of symmetry and displays a slightly distorted octahedral coordination geometry. The asymmetric unit for (II) contains, in addition to half the [Cu(H₂O)₆]²⁺ ion, one 4‐arsonoanilinium cation, a sulfate dianion and a solvent water molecule. Extensive O—H…O and N—H…O hydrogen bonds link all the species, giving an overall three‐dimensional structure. In (III), four of the chloride ligands are related by inversion [Cu—Cl = 2.2826 (8) and 2.2990 (9) Å], with the other two sites of the tetragonally distorted octahedral CuCl₆ unit occupied by symmetry‐generated Cl‐atom donors [Cu—Cl = 2.9833 (9) Å], forming a two‐dimensional coordination polymer network substructure lying parallel to (001). In the crystal, the polymer layers are linked across [001] by a number of bridging hydrogen bonds involving N—H…Cl interactions from head‐to‐head‐linked As—O—H…O 4‐arsonoanilinium cations. A three‐dimensional network structure is formed. Cd^II compound (IV) is isotypic with Cu^II complex (III), but with the central CdCl₆ complex repeat unit having a more regular M —Cl bond‐length range [2.5232 (12)–2.6931 (10) Å] compared to that in (III). This series of compounds represents the first reported crystal structures having the protonated 4‐arsonoanilinium species.     

Two new XP(O)[NHC(CH3)3]2 phosphoramidates,with X = (CH3)2N and [(CH3)3CNH]2P(O)(O)

In N,N′‐di‐tert‐butyl‐N′′,N′′‐dimethylphosphoric triamide, C₁₀H₂₆N₃OP, (I), and N,N′,N′′,N′′′‐tetra‐tert‐butoxybis(phosphonic diamide), C₁₆H₄₀N₄O₃P₂, (II), the extended structures are mediated by P(O)...(H—N)₂ interactions. The asymmetric unit of (I) consists of six independent molecules which aggregate through P(O)...(H—N)₂ hydrogen bonds, giving R₂¹(6) loops and forming two independent chains parallel to the a axis. Of the 12 independent tert‐butyl groups, five are disordered over two different positions with occupancies ranging from to . In the structure of (II), the asymmetric unit contains one molecule. P(O)...(H—N)₂ hydrogen bonds give S(6) and R₂²(8) rings, and the molecules form extended chains parallel to the c axis. The structures of (I) and (II), along with similar structures having (N)P(O)(NH)₂ and (NH)₂P(O)(O)P(O)(NH)₂ skeletons extracted from the Cambridge Structural Database, are used to compare hydrogen‐bond patterns in these families of phosphoramidates. The strengths of P(O)[...H—N]_x (x = 1, 2 or 3) hydrogen bonds are also analysed, using these compounds and previously reported structures with (N)₂P(O)(NH) and P(O)(NH)₃ fragments.     

[Ba6(C2H3O2)12(H2O)3.5], a new hydrate of barium acetate

A new barium acetate phase, di‐μ₅‐acetato‐tri‐μ₄‐acetato‐tri‐μ₃‐acetato‐tri‐μ₂‐acetato‐μ₂‐acetato‐triaquahemiaquahexabarium(II), of analytical formula [Ba₆(C₂H₃O₂)₁₂(H₂O)_3.5], is described. The asymmetric unit contains six independent Ba centres with coordination numbers varying from 7 to 10 arising from bonding to 12 crystallographically independent acetate ligands and four molecules of water, one of which is disordered over two sites both of occupancy 0.5. Bonding to the acetate ligands creates a completely connected three‐dimensional structure. All H atoms of the water molecules participate in hydrogen bonding.     

A rare octacoordinated mononuclear iron(III) spin‐crossover compound: synthesis,crystal structure and magnetic properties

The chemistry of transition‐metal complexes with unusually high coordination numbers has been of interest because of their application in catalytic and biological systems. Deprotonation of the ionogenic tetradentate ligand 6,6′‐bis(1H‐tetrazol‐5‐yl)‐2,2′‐bipyridine [H₂bipy(ttr)₂] in the presence of iron(III) and tetra‐n‐butylammonium bromide, [n‐Bu₄N]Br, in solution resulted in the synthesis of a rare octacoordinated anionic mononuclear complex, tetra‐n‐butylammonium bis[6,6′‐bis(tetrazol‐1‐id‐5‐yl)‐2,2′‐bipyridine]iron(III) methanol hemisolvate dihydrate, (C₁₆H₃₆N)[Fe(C₁₂H₆N₁₀)₂]·0.5CH₃OH·2H₂O or [n‐Bu₄N][Fe{bipy(ttr)₂}₂]·0.5CH₃OH·2H₂O ( 1 ), which has been structurally characterized by elemental analysis, powder X‐ray diffraction (PXRD) and single‐crystal X‐ray diffraction. In 1 , the coordination sphere of the iron(III) ion is a distorted bis‐disphenoid dodecahedron, in which the eight coordination positions are occupied by eight N atoms from two independent tetradentate [bipy(ttr)₂]^2? anionic ligands, therefore forming the anionic [Fe{bipy(ttr)₂}₂]^? unit, with the negative charge balanced by a free [n‐Bu₄N]⁺ cation. An investigation of the magnetic properties of 1 revealed a gradual incomplete spin‐crossover behaviour below 150 K.     

Synthesis,spectroscopic, DFT,biological studies and molecular docking of oxovanadium (IV), copper (II) and iron (III) complexes of a new hydrazone derived from heterocyclic hydrazide

A new Schiff base hydrazone (Z)‐2‐(2‐aminothiazol‐4‐yl)‐N′‐(2‐hydroxy‐3‐methoxybenzylidene) acetohydrazide (H₂L) and its chelates [VO (HL)₂]·5H₂O, [Cu (HL)Cl(H₂O)]·2H₂O and [Fe(L)Cl(H₂O)₂]·3H₂O have been isolated and characterized using different physico‐chemical methods, for example infrared (IR), electron paramagnetic resonance (EPR), thermogravimetric analysis and DTG in the solid state, and ¹H‐NMR, ¹³C‐NMR and UV in solution. Magnetic and UV–visible measurements proposed that the coordination environments are square pyramidal, tetrahedral and octahedral geometries for oxovanadium (IV), Cu (II) and Fe (III), respectively. The ligand acts as mono‐negative NO towards oxovanadium (IV) and Cu (II) ions, and bi‐negative ONO for Fe (III) ion. The geometries of the ligand and its complexes were performed using Gaussian 9 program with density functional theory. The EPR spectral data of oxovanadium (IV) and Cu (II) chelates confirmed the mentioned geometries. The molecular modeling was done, and illustrated bond lengths, bond angles, molecular electrostatic potential, Mulliken atomic charges and chemical reactivity for the inspected compounds. Theoretical IR and ¹H‐NMR of the free ligand were calculated. Furthermore, thermodynamic and kinetic parameters for thermal decomposition steps were studied. Docking study of H₂L was applied against the proteins of both bacterial strains Staphylococcus aureus and Escherichia coli, as well as the protein of xanthine oxidase as antioxidant agent by Schrödinger suite program utilizing XP glide protocol. Furthermore, antimicrobial, antioxidant and DNA‐binding activities of the compounds have been carried out.     

Tracking the dissolution–recrystallization structural transformation (DRST) of copper(II) complexes: a combined crystallographic,mass spectrometric and DFT study

Methanol‐ and temperature‐induced dissolution–recrystallization structural transformation (DRST) was observed among two novel Cu^II complexes. This is first time that the combination of X‐ray crystallography, mass spectrometry and density functional theory (DFT) theoretical calculations has been used to describe the fragmentation and recombination of a mononuclear Cu^II complex at 60 °C in methanol to obtain a binuclear copper(II) complex. Combining time‐dependent high‐resolution electrospray mass spectrometry, we propose a possible mechanism for the conversion of bis(8‐methoxyquinoline‐κ²N,O)bis(thiocyanato‐κN)copper(II), [Cu(NCS)₂(C₁₀H₉NO)₂], Cu1 , to di‐μ‐methanolato‐κ⁴O:O‐bis[(8‐methoxyquinoline‐κ²N,O)(thiocyanato‐κN)copper(II)], [Cu₂(CH₃O)₂(NCS)₂(C₁₀H₉NO)₂], Cu2 , viz. [Cu(SCN)₂( L )₂] ( Cu1 ) → [Cu( L )₂] → [Cu( L )]/ L → [Cu₂(CH₃O)₂(NCS)₂( L )₂] ( Cu2 ). We screened the antitumour activities of L (8‐methoxyquinoline), Cu1 and Cu2 and found that the antiproliferative effect of Cu2 on some tumour cells was much greater than that of L and Cu1 .     

Characterization and thermal studies of nano‐synthesized Mn(II), Co(II), Ni(II) and Cu(II) complexes with adipohydrazone ligand as new promising antimicrobial and antitumor agents

New seven complexes of N₁,N₆‐bis((2‐hydroxynaphthalin‐1‐yl)methinyl))adipohydrazone (H₂L) with MnCl₂•4H₂O, CoCl₂•6H₂O, NiCl₂•6H₂O, CuCl₂•2H₂O, Cu(NO₃)₂•3H₂O, CuSO₄•5H₂O, and Cu(OAc)₂•2H₂O have been prepared and characterized by the aid of elemental and thermal analyses, spectra (FT‐IR, ¹H NMR, MS, UV‐Vis, ESR, X‐ray powder diffraction), molar conductance and magnetic moment measurements. The XRD results unambiguously confirmed the nano‐sized particles of the complexes. The results showed that H₂L behaves as dibasic tetra‐dentate ligand towards the metal ions of interest. The low molar conductance values revealed the non‐electrolytic nature for the chelates. The magnetic moment data, UV‐Vis and ESR spectra denoted the formation of octahedral geometries for Mn(II) and Ni(II) complexes, whereas Co(II), Cu(II) complexes exhibited tetrahedral arrangement. The activation parameters for the thermal decomposition stages were calculated from TGA curves using Coats‐Redfern and Horowitz–Metzger methods. The obtained data were confirmed by 3‐D molecular modeling of the ligand and some complexes. The investigated compounds were screened for their antimicrobial activities against different types of organisms and antitumor activities towards human liver Carcinoma (HEPG2) cell to access their potential chemotherapeutic use. The free ligand (H₂L) exhibited a weak inhibition of cell viability with IC₅₀ of 11.80 μg/ml, complexes 4 , 6 and 7 showed a moderate activity with IC₅₀ of 5.56, 7.71 and 5.67 μg/ml, whereas complexes 1 , 2 , 3 , and 5 displayed a strong anticancer activity with IC₅₀ of 4.65, 3.97, 3.30 and 4.84 μg/ml, compared with IC₅₀ value of 4.73 μg/ml for the doxorubicin (standard cytotoxin drug).     

Synthesis,characterization and in vitro antitumour activity of di‐ and tri‐organotin derivatives of fenbufen

The di‐ and tri‐organotin derivatives of fenbufen (4‐(4‐biphenyl)‐4‐oxobutyric acid), [{(n‐C₄H₉)₂Sn(OCOCH₂CH₂COC₆H₄C₆H₅‐4)}₂O]₂ ( 1 ) and R₃SnOCOCH₂CH₂COC₆H₄C₆H₅‐4 (R?C₆H₅, 2 ; c‐C₆H₁₁, 3 ; C₆H₅C(CH₃)₂CH₂, 4 ), have been prepared and characterized by means of elemental analysis, IR and NMR (¹H, ¹³C and ¹¹⁹Sn) spectroscopies. The crystal structure of 1 , bis[4‐(4‐biphenyl)‐4‐oxobutyrato]tetra‐n‐butyldistannoxane, has been determined and it is a centrosymmetric dimer with two distinct types of carboxylate moieties and tin atoms with distorted trigonal bipyramidal geometries. The in vitro antitumour activity of 1 and 2 against two human tumour cell lines was found to be higher than that for cis‐platin used clinically. Copyright © 2005 John Wiley & Sons, Ltd.     

Polycarboxylate‐Templated Coordination Polymers: Role of Templates for Superprotonic Conductivities of up to 10−1 S cm−1

Three coordination polymers (CPs) have been synthesized based on a [Co(bpy)(H₂O)₄]²⁺ chain (bpy=4,4′‐bipyridine) by a template approach. The frameworks are neutralized by different templated polycarboxylate anions (furan di‐carboxylate (fdc) in Co‐fdc, benzene tri‐carboxylate (btc) in Co‐tri and benzene tetra‐carboxylate (btec) in Co‐tetra). These templates with different degrees of protonation and ionic carrier concentration played significant role on crystal packing as well as formation of well‐directed H‐bonded networks which made these CPs perform well in proton conduction (PC). The PC value reaches to 1.49×10^?1 S cm^?1 under 80 °C and 98 % relative humidity (R.H.) for Co‐tri, which is the highest among CPs/MOFs/COFs and is an example of conductivity in the order of 10^?1 S cm^?1. Co‐tri and Co‐tetra are excellent proton conductors at mild temperature (40 °C) and 98 % R.H. (conductivities up to 2.92×10^?2 and 1.38×10^?2 S cm^?1, respectively).     

Two Nickel(II) Coordination Polymers Based on Tri(p‐carboxyphenyl) phosphane Oxide with Highly Selectively and Sensitively Detection of Acetone

Two nickel(II) coordination polymers, namely, {[Ni_1/2(TPO)_1/3(bib)_1/2(H₂O)] · H₂O}_n ( 1 ), and [Ni(HTPO)(bpy)(H₂O)₂]_n ( 2 ), were assembled from tripodal ligand of tripodal tri(p‐carboxyphenyl) phosphane oxide (H₃TPO) and two N‐donors [bib = 1,4‐bis(imidazolyl)benzene, and bpy = 4,4′‐bipyridine]. Their structures were determined by single‐crystal X‐ray diffraction analysis and further characterized by elemental analysis, IR spectra, powder X‐ray diffraction (PXRD), and thermogravimetric analysis (TGA). Structural analysis reveals that complex 1 is an interestingly 3D (3,4)‐connected {10³}₂{10⁶}₃ net, whereas complex 2 is a 1D polymeric chain, which was further expanded into a 3D supramolecular structure through hydrogen bonds. Luminescent sensing measurements show two nickel CPs can selectively and sensitively detect for acetone from normal solvents (DMF, DMA, DMSO, MeOH, EtOH, CH₃CN, H₂O, and N‐butanol).     

[Cu32(H)20{S2P(OiPr)2}12]: The Largest Number of Hydrides Recorded in a Molecular Nanocluster by Neutron Diffraction

An air‐ and moisture‐stable nanoscale polyhydrido copper cluster [Cu₃₂(H)₂₀{S₂P(OiPr)₂}₁₂] ( 1_H ) was synthesized and structurally characterized. The molecular structure of 1_H exhibits a hexacapped pseudo‐rhombohedral core of 14 Cu atoms sandwiched between two nestlike triangular cupola fragments of (2×9) Cu atoms in an elongated triangular gyrobicupola polyhedron. The discrete Cu₃₂ cluster is stabilized by 12 dithiophosphate ligands and a record number of 20 hydride ligands, which were found by high‐resolution neutron diffraction to exhibit tri‐, tetra‐, and pentacoordinated hydrides in capping and interstitial modes. This result was further supported by a density functional theory investigation on the simplified model [Cu₃₂(H)₂₀(S₂PH₂)₁₂].     

Iron(II) and Nickel(II) Complexes of N‐Alkylimidazoles and 1‐Methyl‐1H‐1, 2, 4‐Triazole: X‐ray Studies,Magnetic Characterization,and DFT Calculations

Using the ligands N‐methylimidazole ( MeIm ), N‐ethylimidazole ( EtIm ), N‐propylimidazole ( PrIm ), and 1‐methyl‐1H‐1, 2, 4‐triazole ( MeTz ) three series with a total of 13 iron(II) complexes were isolated. The series comprise of the following complexes: (a) [Fe( MeIm )₆](ClO₄)₂ ( 1 ), [Fe( EtIm )₆](ClO₄)₂ ( 2 ), [Fe( PrIm )₆](ClO₄)₂( 3 ), [Fe( MeTz )₆](ClO₄)₂ ( 4 ), [Fe( MeIm )₆](MeSO₃)₂ ( 5 ), [Fe( EtIm )₆](MeSO₃)₂ ( 6 ), and [Fe( MeTz )₆](BF₄)₂ ( 10 ); (b) [Fe( MeIm )₄(MeSO₃)₂]( 7 ), [Fe( EtIm )₄(MeSO₃)₂] ( 8 ), and [Fe( PrIm )₄(MeSO₃)₂] ( 9 ); (c) [Fe( MeIm )₄(NCS)₂] ( 15 ), [Fe( EtIm )₄(NCS)₂] ( 16 ), and [Fe( MeTz )₄(NCS)₂] ( 17 ). Single crystal X‐ray diffraction studies were performed on 7 – 10 and 15 – 17 . Temperature dependent magnetic susceptibility measurements were performed on selective examples of all series, and confirmed them to be in the HS state over the range 6–300 K. DFT calculations were performed at BP86/def‐SV(P) and TPSSh/def2‐TZVPP level on all [Fe L ₆]²⁺ complex cations and the neutral complexes 7 – 9 and 15 – 17 . Additionally the four homoleptic nickel(II) complexes [Ni L ₆](ClO₄)₂ ( 11 : L = MeIm ; 12 : L = EtIm ; 13 : L = PrIm ; 14 : L = MeTz ) were synthesized and compounds 11 – 13 structurally characterized. UV/Vis/NIR spectroscopic measurements were carried out on all homoleptic iron(II) and nickel(II) complexes. The 10Dq values were determined to be in the range of 11547–11574 and 10471–10834 cm^–1 for the iron(II) and nickel(II) complexes, respectively.     

Crystal Structures,Magnetic Properties and Catecholase‐Like Activities of μ‐Alkoxo‐μ‐Carboxylato Double Bridged Dinuclear and Tetranuclear Copper(II) Complexes

One μ‐alkoxo‐μ‐carboxylato bridged dinuclear copper(II) complex, [Cu₂(L¹)(μ‐C₆H₅CO₂)] ( 1 )(H₃L¹ = 1,3‐bis(salicylideneamino)‐2‐propanol)), and two μ‐alkoxo‐μ‐dicarboxylato doubly‐bridged tetranuclear copper(II) complexes, [Cu₄(L¹)₂(μ‐C₈H₁₀O₄)(DMF)₂]·H₂O ( 2 ) and [Cu₄(L²)₂(μ‐C₅H₆O₄]·2H₂O·2CH₃CN ( 3 ) (H₃L² = 1,3‐bis(5‐bromo‐salicylideneamino)‐2‐propanol)) have been prepared and characterized. The single crystal X‐ray analysis shows that the structure of complex 1 is dimeric with two adjacent copper(II) atoms bridged by μ‐alkoxo‐μ‐carboxylato ligands where the Cu···Cu distances and Cu‐O(alkoxo)‐Cu angles are 3.5 11 Å and 132.8°, respectively. Complexes 2 and 3 consist of a μ‐alkoxo‐μ‐dicarboxylato doubly‐bridged tetranuclear Cu(II) complex with mean Cu‐Cu distances and Cu‐O‐Cu angles of 3.092 Å and 104.2° for 2 and 3.486 Å and 129.9° for 3 , respectively. Magnetic measurements reveal that 1 is strong antiferromagnetically coupled with 2J =‐210 cm^?1 while 2 and 3 exhibit ferromagnetic coupling with 2J = 126 cm^?1 and 82 cm^?1 (averaged), respectively. The 2J values of 1–3 are correlated to dihedral angles and the Cu‐O‐Cu angles. Dependence of the pH at 25 °C on the reaction rate of oxidation of 3,5‐di‐tert‐butylcatechol (3,5‐DTBC) to the corresponding quinone (3,5‐DTBQ) catalyzed by 1–3 was studied. Complexes 1–3 exhibit catecholase‐like active at above pH 8 and 25 °C for oxidation of 3,5‐di‐tert‐butylcatechol.