The Effect of Solvent on Isomer Formation. Synthesis and Crystal Structures of CdII Complexes with 3-Nitrobenzoate and Thiourea

Abstract

Two crystal forms of bis(3-nitrobenzoato)bis(thiourea)cadmium(II) were obtained by the reaction of Cd(NO₃)₂·4H₂O, 3-nitrobenzoate (mNA) and thiourea (TU) from ethanol and water solutions, respectively. One is cube-shaped and crystallizes in the orthorhombic space group Pbca and consists of discrete mononuclear molecules of bis(3-nitrobenzoato-O,O´)bis(thiourea)cadmium(II) (1). The other form is needle shaped and crystallizes in the triclinic space group P1–.It is comprised of discrete molecules of bis(3-nitrobenzoato-O,O´)bis(thiourea)cadmium(II) (2) and (3-nitrobenzoato-O,O´)(3-nitrobenzoato-O)bis(thiourea)cadmium(II) (3). (1), (2) and (3) are isomers, in which (1) may be regarded as a structural intermediate between (2) and (3) in the 'carboxylate shift' process. The formation of these isomers may be influenced by the solvent effect.