Calcium complex of 2,5-dihydroxybenzoic acid (gentisic acid): synthesis, crystal structure, and spectroscopic properties

AbstractThe synthesis, crystal structure, and spectral characteristics (IR, Raman, and 1H and 13C NMR) of a monomeric hexa(aqua)calcium compound, viz. [Ca(C7H5O4)2(H2O)6]·H2O (C7H5O4 = 2,5-dihydroxybenzoate), are reported. The central Ca(II) located on a twofold axis is eight coordinate in an approximate square antiprismatic environment, bonded to two monodentate 2,5-dihydroxybenzoate ligands via the carboxylate oxygen, and six waters. The adjacent monomeric units are linked with the aid of several O–H⋯O hydrogen bonds.