Oxidation state dependent cis/trans isomerization in ML2 complexes of the heteroscorpionate ligand, (2-hydroxyphenyl)bis(pyrazolyl)methane and its derivatives with iron and cobalt

The synthesis and characterization of the Fe(III) and Co(II:III) complexes of tridentate heteroscorpionate ligands, (2-hydroxyphenyl) bis(pyrazolyl)me thane, L1, and its derivatives, L2 and L3 are reported. Complexes prepared include [Fe(L)(2)][ClO4] where L = 1-3, [Co(L3)(2)], [Co(L3)(2)][BPh4], and [Co(L)(2)](2)Ag(MeCN)[BF4](3) where L = 1 and 2. X-ray crystallographic an alysis of several of the complexes have been completed. Electrochemical and other methods show that there is an oxidation state and ligand dependant c is/trans isomerization in these complexes. (C) 1999 Elsevier Science S.A. A ll rights reserved.