Hydrothermal synthesis of chiral inorganic-organic CoII complex: Structural, thermal and catalytic evaluation

Abstract

By heating the cobalt chloride hexahydrate (CoCl2•6H2O) with the R form of the organic amine α-methylbenzylamine (C 8 H 11 N) under hydro(solvo)thermal conditions, we have successfully generated the corresponding non-centrosymmetric homochiral hybrid tris(αmethylbenzylammonium tetrachloridocobaltate chloride [R-(C 8 H 12 N) 3 ][CoCl 4 ]Cl abbreviated R(MBA)Co. We present the growth conditions together with a characterization of the single crystals by means of X-ray single-crystal diffraction, Fourier-transform infrared, TG/TDA thermal decomposition and catalytic properties. This inorganic-organic hybrid compound crystallizes in the chiral space group P21 and exhibits a supramolecular-layered organization wherein a double layer of (R)-methylbenzylammonium cations and the uncoordinated chloride anions are sandwiched between anionic layers, formed by isolated tetrachloridocobaltate tetrahedra. The crystal packing is governed by a three-dimensional network of N/C-H•••Cl hydrogen bonds between the inorganic and organic moieties and C-H•••π interactions between the aromatic rings of the organic moieties themselves. Thermal analysis discloses a phase transition at the temperature 130 °C. The Co complex was also employed as suitable catalyst activating the acetal formation reaction of aldehydes using MeOH as solvent and as the unique source of acetalisation.

Structural Study, Vibrational, Optical, Thermal Properties and Hirshfeld Surface Analysis of a New Iron (III) Complex: FeCl<sub>4</sub>(C<sub>5</sub>N<sub>2</sub>H<sub>6</sub>)(C<sub>5</sub>N<sub>2</sub>H<sub>5</sub>)

“…This stage is characterized by an endothermic peak at 298˚C. In the final step, the TG trace shows an 8.372% loss in weight, which is calculated in the order of 10.02% in the range 330˚C -378˚C, indicating the conversion to 1/2 FeCl [33]. This step is corresponded to an endothermic peak at 348˚C.…”