ISSN print edition: 0366-6352
ISSN electronic edition: 1336-9075
Registr. No.: MK SR 9/7
Synthesis, spectral and electrochemical study of coordination molecules Cu4OX6L4: 3-cyanopyridine Cu4OBrnCl(6−n)(3-CNpy)4 complexes
Gregor Ondrejovič, Adela Kotočová, Marian Koman, and Peter Segľa
Institute of Inorganic Chemistry, Technology and Materials, Faculty of Chemical and Food Technology, Slovak University of Technology, SK-812 37 Bratislava, Slovak Republic
Received: 4 September 2009 Revised: 19 November 2009 Accepted: 30 November 2009
Abstract: Seven new 3-cyanopyridine Cu4OBr n Cl(6−n)(3-CNpy)4 (n = 0–6) complexes were prepared and studied by infrared spectra, electronic spectra, and cyclic voltammetry. Infrared spectra revealed a distortion of the tetrahedral Cu4O core to C 2ν or C 3ν symmetries and a donor-acceptor vibrational coupling with the in-plane pyridine ring bending within the O-Cu-(pyridine ring)CN system involving the π-back bonding between Cu(II) atoms and 3-CNpy ligands. Bands of the electronic spectra and half-wave potentials of the complexes are consistent with the weak donor and strong acceptor behaviour of the 3-CNpy ligands. The results were compared with analogous complexes of pyridine, 3-substituted and 4-substituted pyridine ligands.
Keywords: copper(II) 3-cyanopyridine complexes - donor-acceptor vibrational coupling - electronic spectra - electrochemistry -
Full paper is available at www.springerlink.com.
Chemical Papers 64 (3) 339–345 (2010)