2-Pyridyl aldoxime in cobalt carboxylate chemistry: Synthesis and characterization of trinuclear complexes

The use of 2-pyridyl aldoxime (pyCHNOH) in cobalt carboxylate chemistry has yielded compounds 2[(Co3O)-O-III(O2CPh)(3)(pyCHNO)(3)][Co-3(II)(O2CPh)8] . 7.67MeCN (1 . 7.67MeCN) and [(Co3O)-O-III(O2CPh)(3)(pyCHNO)(3)] (PhCO2) . 0.5PhCO(2)H . 2MeCN (2 . 0.5PhCO(2)H . 2MeCN) in mixture, as well as compounds 2[(Co3O)-O-III (O(2)Cph)(3)(pyCHNC)(3)](PhCO2)(NO3). ThCO2H) - H2O (3 - PhCO2H . H,C) and [(Co2CoII)-Co-III(OH)Cl-3(pyCHNO)(4)] 0.5MeCN . 0.5H(2)O (4 - 0.5MeCN - 0.5H(2)O). Complexes 1-3 have been isolated from the 1:11:2 COX2(X=Cl-,NO3-)/pyCHNOH/PhCO2Na molar ratio reactions in MeCN, whereas the 1:11 COX2(X= CI-)/pyCHNOH/PhCO2Na molar ratio reaction in MeCN afforded complex 4. Compounds 1-3 contain the cation [(Co3O)-O-III(O2CPh)(3)(pyCHNC)(3)](+) representing the first triangular oxo-centred Co-III cluster with pyCHNC(-), whereas compound 4 displays an unusual structural motif consisting of dinuclear [Co-2(III)(mu(2)-OH)(pyCHNO)(4)](+) and tetrahedral [(CoCl3)-Cl-II](-) units bridged by an oximatc, oxygen atom of the ligand. (C) 2008 Elsevier B.V. All rights reserved.