Synthesis, X-ray crystal structure and vibrational spectra of a polymeric copper(II) complex with 2-thiopheneacetic acid

The crystal structure of a novel polymeric copper(II) complex with 2-thiopheneacetic acid is presented and the vibrational spectra are discussed. The copper(II) atoms and coordinating carboxylate oxygen atoms form the [Cu2O8] dinuclear units typical for other carboxylates of this metal. The units are directly linked via two, relatively short Cu–O interactions and form polymeric chains along the b axis. A structural two- and threefold disorder has been found for the thiophene rings. The IR and Raman spectra of the title complex and free ligand are interpreted with help from literature data and deuteration effects. The absorption bands that are related to Cu–Cu core vibrations have been localized by a 63Cu–65Cu labelling technique.