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

By heating the cobalt chloride hexahydrate (CoCl·6HO) with the R form of the organic amine α-methylbenzylamine (CHN) under hydro(solvo)thermal conditions, we have successfully generated the corresponding non-centrosymmetric homochiral hybrid tris (α-methylbenzylammonium tetrachloridocobaltate chloride [R-(CHN)][CoCl]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 P2 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 acetalization.R.P.H. thanks Ministerio de Economía, Industria y Competitividad MINECO-FEDER CTQ2017-88091-P and Diputación General de Aragón (DGA) (Research Group E07-17R) for financial support of her research.Peer Reviewe