The new binucleating ligand 3,5-bis(1′-(4′-(2″-pyridyl)-2′-thiabutyl))pyrazole (BLEPH) forms dinuclear Cu11 complexes which are able to bind one additional exogenous bridging molecule such as N3-, C1-, Br- and OH-. Three of these complexes [Cu2(BLEP)(μ-N3)(N3)2] (1); [Cu2(BLEP)(μ-C1)(C1)(H2O)]C1 (2); and [Cu2(BLEP)(μ-Br)(Br)(H2O)]Br (3) were characterized by X-ray single crystal structure analysis. The two copper centers are bridged by the central pyrazolyl group of the BLEP and one azide (in 1), one chloro (in 2) or bromo (in 3) and the side arm of BLEP coordinates to each of the coppers with one pyridyl N and one thia S. Electrochemical studies of these complexes reveal that the redox waves are -247 and 15 mV for 2; -215 and 37 mV for 3 corresponding to the Cu11Cu11/Cu1Cu11 and Cu1Cu11/Cu1Cu1 couples, and -291 mV for 1 corresponding to the Cu11Cu11/Cu1Cu1 process, respectively. The intramolecular magnetic exchange coupling (J = -46.6 cm-1) in the bromo-bridged complex shows weaker antiferromagnetic interaction than the N3-bridged complex. The exchange coupling process through μ2-N3 ligand enhances the net antiferromagnetic interaction. Electronic spectra covering the 12 500-50 000 cm-1 region are also reported for these complexes.
- Antiferromagnetic interactions
- Pryrazolyl groups
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry