Inorganic cobaloximes with mixed dioxime equatorial ligands: a convenient one pot synthesis and cis influence studies: X-ray crystal structures of N3CoIII(dmgH)(dpgH)Py and N3CoIII(chgH)(dpgH)Py

A simple and general route to the synthesis of cobaloxime with mixed dioxim e Ligands, XCo(L)(L ' )Py, L,L ' = dmgH/dpgH and chgH/dpgH; X = Cl, Br, NO2 , N-3, has been described. These compounds are reported for the first time. The synthesis is confirmed by the X-ray structures of N3Co(dmgH)(dpgH)Py a nd N3Co(chgH)(dpgH)Py. The cis and trans effects on these complexes and on XCo(L)(2)Py (L = dmgH, chgH, dpgH; X = Cl, Br, NO2, N-3) complexes have bee n studied by 'H-, C-13-NMR, UV, and X-ray. For a range of X ligands, a clea r trend between the H-1, C-13 chemical shifts of the equatorial and axial l igands as well as with the Co-dioxime CT band has been observed. The analys is of the C-13 values and X-ray data shows that one dioxime wing effects th e other dioxime wing in the mixed dioxime complexes. (C) 2001 Elsevier Scie nce B.V. All rights reserved.