Zinc(II) di(o-hydroxybenzoate) complexes with imidazole and its derivativesSynthesis,thermal characterization and molecular structures

Mixed complexes of the type: Zn(Hsal)₂(Him)₂, Zn(Hsal)₂(Him)₅, Zn(Hsal)₂(4-MeHim)₂ and Zn(Hsal)₂(1,2-diMeim)₂ (where Hsal=OHC₆H₄COO^-, Him=imidazole, 4-MeHim=4-methylimidazole, 1,2-diMeim=1,2-dimethylimidazole) have been synthesized. The application of chemical, thermal and X-ray methods has enabled us to analyze the complexes and their sinters. The gaseous products of pyrolysis of Zn(Hsal)₂(Him)₂ and Zn(Hsal)₂(4-MeHim)₂ have been investigated. Thermal decomposition pathways have been postulated for synthesized complexes. The molecular structures of the Zn(Hsal)₂(Him)₂ and Zn(Hsal)₂(1,2-diMeim)₂ have been solved.     

Crystal and molecular structures of methyl (2-hydroxy-3-oxo-5-p-tolyl-2,3-dihydrofuran-2-yl)acetate

Institute of Chemical Physics in Chernogolovka, Russian Academy of Sciences. Institute of Technical Chemistry, Russian Academy of Sciences. A. M. Gorkii Perm State University. Translated fromZhurnal Struktumoi Khimii, Vol. 36, No. 5, pp. 952–956, September–October, 1995.     

Crystal structures of copper(II) and zinc(II) complexes derived from 3-(2-pyridyl)pyrazole

Two dinuclear complexes [Zn(μ-L)(NO₃)(H₂O)]₂ (1) and [Cu₂(μ-L)₂(HL)₂](NO₃)₂(C₁₂H₈Br₂)_0.5·H₂O (2), (HL = 3-(2-pyridyl)pyrazole, C₁₂H₈Br₂ = 4,4′-dibromobiphenyl) are synthesized under hydrothermal conditions and characterized by elemental analysis and X-ray single crystal diffraction. Crystal data for 1: triclinic, \(P\bar 1\), a = 8.8478(7) Å, b = 15.0550(11) Å, c = 16.4310(12) Å, α = 107.588(4)°, β = 112.498(3)°, γ = 115.595(3)°, V = 2099.8(9) ų, Z = 2; for 2: triclinic, \(P\bar 1\), a = 7.2870(15) Å, b = 8.6840(17) Å, c = 9.3290(19) Å, α = 107.588(4)°, β = 112.498(3)°, γ = 115.595(3)°, V = 528.77(18) ų, Z = 1. Complex 1 and 2 are both dinuclear structures which are further packed into a 1D supramolecular chain and a 3D supramolecular framework via weak C–H…O hydrogen bond interactions respectively.     

Platinum(II) complexes with 9,10-phenanthraquinone and 3-hydroxy-2-methyl-4-pyrone

Conclusions The Pt(II) complexes with 9,10-phenanthraquinone and 3-hydroxy-2-methyl-4-pyrone were obtained and characterized.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 900–902, April, 1981.     

Crystal structures of copper(II) and nickel(II) complexes with 1,3-bis(3,5-di-tert-butylsalicylideneamino)propan-2-ol

Mononuclear copper(II) and nickel(II) complexes with 1,3-bis(3,5-di-tert-butylsalicylideneamino)propan-2-ol (H₃L) of the general formula [M(HL)] were obtained and structurally characterized. It was demonstrated that the presence of the tert-butyl groups precludes intermolecular hydrogen bonding in the crystals of the complexes and that their molecules are only linked by hydrophobic interactions.     

Synthesis,crystal structures and spectral characterization of Cu(II) and Mn(II) complexes of 4-hydroxy-3-methoxybenzaldehyde: antioxidant properties and molecular docking studies

[Cu(L)₂(H₂O)₂] (1) and [Mn(L)₂(H₂O)₂] (2) (HL = 4-hydroxy-3-methoxybenzaldehyde) were synthesized and characterized using elemental, spectral (FTIR, ESI-MS, UV–visible, fluorescence and EPR), thermal, cyclic voltammetric, powder, and single crystal X-ray crystallographic studies. Spectral and X-ray data ascertained the structural features, binding modes of ligand and distorted octahedral geometry around the metal ions. Cyclic voltammetric studies confirmed the formation of a quasi reversible redox couple in solution. Crystal structure analysis of 1 and 2 reveal the presence of non-covalent interactions, resulting in a 1-D polymeric chain. Antioxidant properties (using DPPH and hydrogen peroxide assay) and molecular docking studies (using 1BNA) are also examined. The binding free energies (calculated from docked models), ?270 (1) and ?295 kJ mol^?1 (2), suggest that the complexes reasonably bind to DNA, and the DNA-binding affinity of 2 is stronger than that of 1.     

Effect of interligand repulsion of the molecular structures of bis-(dithiocarbamato) metal(II) complexes

A survey of the structural data on M(R₂dtc)₂, where R₂dtc⁻ is R₂NCS₂⁻ and M^II  Fe, Ni, Cu, Se, Te, Zn, Cd, Hg and Pb, has revealed that the ligand is essentially uncharged upon coordination to the metal ion and consequently should be considered as stereochemically rigid. A correlation between b (normalized bite distance) and r_M (ionic radios of M) has been found and explained in terms of constant ∡SCS and variable r_M. Both R(MS) and ∡SMS in this model are defined by the approach of M to the rigid CS₂ group. The interligand repulsion was found to depend heavily on the ligand's bite angle. The distortion of the molecular structures of M(R₂dtc)₂ in the crystal state from the regular pseudotetrahedral or planar arrangements was explained as a means of reducing the interligand repulsion energy when an additional (intermolecular) contact is formed in the crystal due to crystal packing requirements.     

Synthesis,characterization, and antimicrobial activities of two mononuclear metal(II) complexes with (Z)-3-hydroxy-4-(3-hydroxy-3-phenylacryloyl)phenyl benzoate

Two mononuclear complexes with a β-diketone ligand (Z)-3-hydroxy-4-(3-hydroxy-3-phenylacryloyl)phenyl benzoate (L), [CoL₂(CH₃CH₂OH)₂] (1), and [MnL₂(CH₃CH₂OH)₂] (2) were prepared. Both complexes were characterized by X-ray crystallography, confirming that the central metal(II) are coordinated by four oxygens from two L and two oxygens from two ethanols. Both complexes were assayed for in vitro antibacterial (Bacillus subtilis, Staphylococcus aureus, Streptococcus faecalis, Pseudomonas aeruginosa, Escherichia coli, and Enterobacter cloacae) activities and showed better antimicrobial activity against Gram positive strains than Gram negative strains.     

Crystal structures and electrochemical properties of two Mn(II) 2-sulfoterephthalate complexes with N-donor ligands

Two Mn(II) sulfoterephthalate complexes, [Mn(HStp)(o-Phen)₂] (I) and [Mn(HStp)(2,2′-Bipy)₂] (II) (H₃Stp = 2-sulfoterephthalic acid, o-Phen = 1,10-phenanthroline, 2,2′-Bipy = 2,2′-bipyridine), were synthesized under hydrothermal condition. Single crystal X-ray diffraction analyses reveal that complexes I and II possess similar structure, in which the center Mn²⁺ ions are hexa-coordinated with one Hstpanion and two N-donor ligands. For both of them, the formation of 3D supramolecular structures are based on both H-bonds and π...π/C-H...π stacking interactions. Electrochemical properties of complexes I and II have been investigated by means of cyclic voltmetry, which shows that electron transfer between Mn(III) and Mn(II) in electrolysis is quasi-reversible process.     

Crystal structures and luminescence of two zinc(II) complexes with benzimidazole ligands

Two new zinc(II) complexes have been synthesized and studied by single crystal X-ray diffraction method: [Zn(L1)Cl₂]·2DMF (1) and [Zn(L2)Cl₂]·DMF (2) (L1 = 3,3′-bis(2-benzimidazolyl)-2,2′-dipyridine, L2 = 3,3′-bis[2-bis(2-ethylbenzimidazolyl)]-2,2′-dipyridine). Compound 1 is monoclinic, C2/c, a = 23.142(3) ?, b = 11.845(1) ?, c = 14.735(3) ?; compound 2 is orthorhombic, C222₁, a = 12.140(7) ?, b = 16.283(9) ?, c = 16.51(1) ?. In both compounds, Zn(II) cations are coordinated by two chlorine atoms and two benzimidazole nitrogen atoms in a slightly distorted tetrahedron fashion. Structural features responsible for fluorescent properties of the complexes are discussed.     

Crystal and molecular structures of triaquabis(5-nitro-2-acetamidobenzoato)copper(II) dihydrate

A new copper(II) complex [Cu(5-NO₂-2-CH₃CONHC₆H₃COO)₂(H₂O)₃] · 2H₂O was synthesized by the reaction of sodium 5-nitro-5-acetamidobenzoate with CuSO₄ · 5H₂O (2: 1), and its structure was determined by X-ray diffraction. Crystals are monoclinic: a = 11.7146(7) Å, b = 16.8463(10) Å, c = 13.2408(9) Å, β = 113.896(5)°, Z = 4, ρ_calc = 1.668 g/cm³, space group P2₁/c, R = 0.0338. In the monomer complex, the copper atom has an elongated square-pyramidal coordination (4 + 1); the coordination sphere is formed by two oxygen atoms of the carboxylate groups of two monodentate organic ligands and the three oxygen atoms O(w) of the water molecules (the O(3w) atom is in the axial position). In the structure, the complex molecules are linked by hydrogen bonds involving two uncoordinated water molecules.     

New metal complexes with di(mono)acylhydrazidate molecules

The simple hydrothermal self-assemblies between metal salts, organic polycarboxylic acids and N(2)H(4)·H(2)O, sometimes in the presence of phenanthroline (phen), created four di(mono)acylhydrazidate-coordinated compounds [Pb(2)(DPHKH)(2)(phen)(2)]·2H(2)O 1, [Cd(ODPTH)(phen)]·0.25H(2)O 2, [Pb(2)(MPTH)(4)(phen)(2)] 3, [Cd(2)(MPTH)(4)(phen)(2)]·H(2)O 4 as well as one diacylhydrazide molecule [H(2)(ODPTH)] 5 (DPHKH = 4,4'-diphthalhydrazidatoketone hydrazone, MPTH = 3-methylphthalhydrazidate, ODPTH = 4,4'-oxydiphthalhydrazidate). Note that the di(mono)acylhydrazidate molecules in the title compounds originated from the in situ acylation reactions between organic polycarboxylic acids and N(2)H(4)·H(2)O. Interestingly, another kind of ligand in situ reaction was found in the formation process of DPHKH in compound 1: the nucleophilic addition reaction of a ketone with N(2)H(4)·H(2)O.     

Group II metal complexes with the N-(2-oxy-3,5-di-tert-butylphenyl)-4,6-di-tert-butyl-o-iminobenzoquinone ligand: an ESR study

The Group II metal (Mg, Ca, Sr, Ba, Zn, Cd) complexes based on the paramagnetic N-(2-oxy-3,5-di-tert-butylphenyl)-4,6-di-tert-butyl-o-iminobenzoquinone ligand were generated in solutions and studied by ESR spectroscopy. The magnesium, zinc, and cadmium complexes with trialkylphosphine ligands were prepared. Their molecular structures and electron density distribution were studied by ESR spectroscopy and DFT calculations.     

Crystal and molecular structures of two europium(III) nitrate complexes with triphenylphosphine oxide

The X-ray structures of the complexes Eu(NO₃)(Ph₃PO)₃(acetone)₂ (A) (Ph₃PO = triphenylphosphine oxide) and Eu(NO₃)₃(Ph₃PO)₂(ethanol) (B) have been solved by the heavy-atom method, by using the three-dimensional Patterson-Fourier synthesis. The crystals are both monoclinic and belong to the space group P2₁/n, with Z = 4. The cell dimensions are: a = 27.825(4) Å, b = 19.422(4) Å, c = 11.238(2) Å, β = 94.9(3)° for A; and a = 22.193(4) Å, b = 10.866(2) Å, c = 17.101(3) Å, β = 105.6(3)° for B. In both complexes the europium(III) ion is ennea-coordinated to three chelate nitrate groups and three oxygens of the Ph₃PO ligands for A and two of the Ph₃PO and one of the ethanol for B. The acetone molecules of A are outside the coordination sphere of the metal and disordered.