Some nickel(II) complexes with pentadentate and tridentate heterocyclic N-and S-donor ligands

High-spin Ni(II) complexes of the linear pentadentate ligand 2,6-bis([2'-am inophenylthio]methyl)pyridine (Batp) and the tridentate ligands ([2'-aminop henylthio]ethyl)pyridine (Atep) 1,5-bis(N-methylbenzimidazol-2'-yl)-3-oxape ntane (Mbeo) have been prepared. (Crystal structures of the complexes [Ni(B atp)(H2O)](CF3SO3)(2) (2) and [Ni(Atep)(2)](ClO4)(2) (3) reveal pseudooctah edral coordination. Tetragonal distortion in [Ni(Mbeo)(2)](ClO4)(2) (5) is evident from the longer Ni-O and shorter Ni-N bond lengths. From the electr onic spectrum of 5, the tetragonal distortion parameter D-t and the in-plan e Dq(xy) and axial Dq(z) Iigand field parameters are calculated. The three NI(II) complexes exhibit irreversible cathodic electrochemistry. (C) 2000 E lsevier Science S.A. All rights reserved.