Sanchay J. Bora

Structural, thermal and spectroscopic properties of supramolecular coordination solids

Molecules in metal isonicotinate tetrahydrates, M(NC5H4-p-CO2)2.4H2O with M = Mn, Fe, Co, Ni, Cu, Zn, consisting of the hexacoordinate complexestrans-[M(NC5H4-p-CO2)(OH2)4], participate in exhaustive hydrogen-bond formation among themselves to lead to a robust 3D supramolecular network in the solid state. Solid-state diffuse reflectance UV-Vis-NIR spectra of the complexes have been assigned to ligand field and charge transfer transitions. Sharp weight loss due to dehydration, as shown by TGA of Cu(NC5H4-p-CO2)2.4H2O, suggests the suitability of this complex for the gravimetric estimation of copper.

Inverse bilayer structure of mononuclear CoII and NiII complexes of the type M(H2O)3(SO4)(4-CNpy)2

Two new metal compounds of the formula [M(H(2)O)(3)(SO(4))(4-CNpy)(2)] x H(2)O [M = Ni (1) and Co (2), 4-CNpy = 4-cyanopyridine] have been prepared and studied by X-ray diffraction. In both of these compounds the 4-CNpy ligands are coordinated via pyridyl-N atoms to the metal ions in a cis fashion. The neutral complexes along with the uncoordinated H(2)O molecules are glued together preferentially into inverse bilayers by non-covalent interactions, including unique interlayer pi-pi interactions between antiparallel nitrile groups. Hartree-Fock and density-functional theory (DFT) calculations indicate that the pi-pi interactions are energetically significant. The unit-cell similarity index (Pi) of 0.0046 for the compounds suggests their isostructurality, which is also supported by their X-ray powder diffraction patterns that can be almost superimposed.

Tetrakis(μ‐benzoato‐κ2O:O)bis{[4‐(dimethylamino)pyridine‐κN1]copper(II)}

The title compound, [Cu2(C(7)H(5)O(2))4(C(7)H(10)N(2))2], is a crystallographically centrosymmetric binuclear complex, with Cu atoms [Cu...Cu = 2.6982 (4) A] bridged by four benzoate ligands. Each of the Cu atoms in this bunuclear copper(II) acetate hydrate analogue is present in an approximately square-pyramidal environment, with four O atoms in a plane and the pyridine N atom at the apical site. Selected geometric parameters are compared with values for related tetrabenzoate complexes of copper(II).

CCDC 1555377: Experimental Crystal Structure Determination

Related Article: Sanchay J. Bora, Rima Paul, Mithun Nandi, Pradip K. Bhattacharyya|2017|J.Solid State Chem.|256|38|doi:10.1016/j.jssc.2017.08.034

Crystal structure of bis­(μ-4-nitro­benzoato-κ2O:O′)bis­[bis­(4-methyl­pyridine-κN)(4-nitro­benzoato-κ2O,O′)manganese(II)]

The crystal structure of a dinuclear tetracarboxylate complex of manganese(II) is reported wherein the MnII atoms are bridged by two carboxylate anions.