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A dimeric [{Fe(5-ClL1)}₂(m-O)], [H₂-5-ClL1 = N,N¢-bis(5-Chloro-2-hydroxybenzylidene)- 2-methylpropane-1,2-diamine] tetradentate Schiff-base complex, 1, has been synthesized and its crystal structure has been determined by single crystal X-ray diffraction analysis. Structural analysis of complex 1 shows that the complex is a centrosymmetric dimer. Each of the Fe(III) ions has a five-coordinate geometry and one oxygen atom bridges two Fe(III) ions to form a m-oxo structure. The geometry around iron atom can be described as a square based pyramid with the FeN₂O₂ coordination plane and oxo ligand.

The single crystal X-ray diffraction (XRD) method was used to determine the structure of the [Cu(mi-tfac)₂] (mi-tfac = MeC(O)CHC(NMe)CF₃) complex at the temperature of 150 K. The crystallographic data are as follows: space group Pnna , a = 11.8798(16) Å, b = 12.0315(16) Å, c = 10.6259(14) Å, V = 1518.8(4) ų, Z = 4, R = 0.0288. The structure is molecular, the coordination environment of copper in the molecule adopts a distorted tetrahedral geometry. The Cu-O and Cu-N distances are 1.9182(13) Å and 1.9610(16) Å respectively, the OCuN chelate angle is 94.18(5)°. The thermal properties of the compounds [Cu(mi-tfac)₂] and [Cu(RC(O)CHC(NMe)R)₂] (R = Me, ^t Bu) in the condensed phase have been studied by the methods of thermogravimetry and differential scanning calorimetry. The thermodynamic characteristics of the melting processes have been determined.

A new Cu (II) complex with bidentate o-phenanthroline (phen) ligand, ([Cu(phen)]₂(H₂PO₄)₂×_{×HPO4)2(H3PO4)4, has been synthesized and characterized by single crystal X-ray diffraction, IR spectroscopy and magnetic data. The crystal structural analysis shows that the title compound contains two phosphate-bridged dimeric units ([Cu(phen)]2(H2PO4)HPO4), which are crystallographically independent. In these units, each copper atom is five coordinated and the geometry around the Cu(II) can be described as slightly distorted square-based pyramidal, with parameter varying between 0.001 and 0.04. The crystal structure is stabilized by O-H…O and C-H…O hydrogen bonds between the dimeric units and the phosphoric acid molecules. In addition, the organic ligands are associated by π-π stacking interactions between neighboring non-nitrogen aromatic rings. The infrared spectrum recorded at room temperature was interpreted on the basis of data published in the literature. The magnetic susceptibilities data show a weak intra-dimer ferromagnetic interaction with J = 31.8 K.}

The preparation of four new copper(II) complexes with different N-donor ligands [CuBr₂×(2-benzylpyridine)₂] (1), [CuBr₂(2-benzylpyridine)(2,2'-bipyridine)]×H₂O (2), [CuBr₂(3-methyl-2-phenylpiridine)₂] (3), [Cu(picolinate)₂]×KI (4) from copper(I) halides as starting material is described. During the preparation of compound 4 a ligand oxidation reaction took place to give the picolinate ligand starting from 2-(2-methylaminoethyl)pyridine. The complexes were characterized by elemental analyses, IR spectroscopy and crystallographic studies. Single crystal X-ray diffraction analysis of the complexes reveals their monomeric penta- and tetracoordinated nature. For all compounds, the copper(II) present a common square planar coordination except for compound 2 which is five coordinated in a quasi-square pyramidal configuration with t of 0.29. The Cu-N distances for these compounds are in the range of 1.959(4)-2.041(3) Å, Cu-O distance was 1.961(3) Å and Cu-Br distances were in the range of 2.4052(4)-2.4381(6) Å for the square base configuration while for apical distance it was 2.6745(7) Å. Magnetic properties have been investigated for all compounds in the temperature range 2-300 K. Compound 1 shows weak antiferromagnetic intermolecular interaction.

A new Zn(II) coordination polymer, {[Zn(npht)(L)_0.5(H₂O)]×H₂O} _n (L = 1,4-bis(2-methylbenzimidazol-1-ylmethyl)benzene, H₂npht = 3-nitrophthalic acid) has been hydrothermally synthesized and characterized by elemental analysis, IR, XRPD, and single-crystal X-ray diffraction. The Zinc(II) coordination compound exhibits a 1D linear chain, which is further assembled into a 2D supramolecular layer via two modes of classial hydrogen bonding interactions. The fluorescence properties and thermal stability of the complex have been investigated in the solid state.

A new coordination polymer, {[Cd(bbmb)(bdc)]} _n (bbmb = 1,1¢-(1,4-butanediyl)bis-(2-methylbenzimidazole), H₂bdc = 1,3-benzenedicarboxylic acid) was synthesized under hydrothermal conditions. The complex was structurally characterized by single crystal X-ray diffraction analyses, infrared spectroscopy (IR), elemental analyses. The compound crystallizes in the monoclinic system, space group P 2₁/ c with a = 10.860(6) Å, b = 13.115(7) Å, c = 21.009(9) Å, b = 120.94(2)°, V = 2567(2) ų, Z = 4, C₂₈H₂₆CdN₄O₄, M_r = 594.93, D_c = 1.540 g/cm³, m = = 0.893 mm^-1. Each cadmium center is six coordinated with four O atoms from two bdc^2- anions, and two N atoms of two bbmb ligands. The complex features a 4-connected 2D (4, 4) sheet with a point symbol {4².6²}. Fluorescence properties of the title complex were investigated.

A two-dimensional (2D) coordination polymer, formulated as [Y₄(m₃-OH)₄(hma)(cba)₅] _n × × n (Hcba) (1), is synthesized by the synergistic coordination of hemimellitate (H₃hma) and 4-chlorobenzoate (Hcba) ligands with Y₂O₃ under hydrothermal conditions. It has been characterized by single-crystal X-ray diffraction, powder XRD, thermogravimetric analysis, elemental analysis and infrared spectroscopy. Single-crystal X-ray diffraction reveals that it crystallizes in the triclinic crystal system, P space group. Unit cell parameters: a = 11.0280(6) Å, b = 14.5791(10) Å, c = 18.9515(12) Å, a = 72.233(6)°, b = 82.641(5)°, g = 70.933(5)°, V = 2741.1(3) ų, Z = 2. The asymmetric unit contains a [Y₄(m₃-OH)₄]⁸⁺ core which is extended into an infinite {[Y₄(m₃-OH)₄]⁸⁺} _n chain along the direction of a axis. Every {[Y₄(m₃-OH)₄]⁸⁺} _n chain is further connected to two neighboring chains by hma^3- ligands along the direction of b axis, forming a 2D yttrium-organic layer in the ab plane. Adjacent layers are further packed with each other via hydrophobic interactions to form a three-dimensional (3D) structure.

New hybrid organic-inorganic complex zirconium and hafnium fluorides with the 4-amino-1,2,4-triazolium cation (C₂H₅N₄)₂MF₆ (M = Zr, Hf, Zr _x Hf_{1- x} ), which crystallize in two polymorphs (monoclinic ( P 2₁/ n , Z = 4) and triclinic ( P , Z = 2)) are synthesized and structurally studied for the first time. The structures of both polymorphs are composed of hydrogen bonded (N-H⋯F and C-H⋯F) 4-amino-1,2,4-triazolium cations protonated via the nitrogen atom in site 1 and complex [M₂F₁₂]^4- anions that are centrosymmetric dimers formed by edge-sharing pentagonal bipyramids MF₇ (M = Zr, Hf, Zr _x Hf_{1- x} ). It is found that in the structures studied 4-amino-1,2,4-triazolium cation occur simultaneously as cis- and trans- conformers. The packing character of structural units in the unit cells of the studied crystals is discussed along with the structure of the neutral and protonated forms of 4-amino-1,2,4-triazole.

A novel inorganic-organic hybrid salt, hexanediammonium heptamolybdate (C₆H₁₈N₂)₂[H₂Mo₇O₂₄]×7H₂O has been synthesized and characterized by elemental analyses, IR, TGA, cyclic voltammetry, UV and X-ray single crystal diffraction. It crystallizes in triclinic space group P -1 with a = 10.0619(2) Å, b = 12.059(2) Å, c = 20.044(3) Å, a = 97.06(1)°, b = 91.56(1)°, g = 110.59(2)° and Z = 2. The crystal structure shows that seven MoO₆ distorted octahedra share edges which have four ranges of Mo-O bond distances. The heptamolybdate anion of the crystal has approximate mm 2 point symmetry and its structure is similar to that observed in other heptamolybdates. The titled compound consists of the protonated hexanediamine cations and the inorganic [H₂Mo₇O₂₄]^4- oxomolybdate anions, linked by hydrogen-bonding interactions.

The title complex [Ru(Cl)₂(CO)(py)₂(AsPh₃)], was synthesized and characterized. The molecular structure and crystal structures are determined by X-ray crystallography. The dihedral angle between the two cis -pyridine rings is 73.3(2)°, which shows that they are almost orthogonal to each other. The molecular structure is stabilized by inter-molecular and intra-molecular C-H…Cl interactions. The molecular structure is further stabilized by interactions between the aromatic rings.