Synthesis, Crystal Structure and Electrochemical Behavior of Two New Ni-based Complexes: [Ni-2(ttpy)(2)(SCN)(4)] and [Ni(ttpy)(2)](CH3OH)(2) (2I)

Abstract

A simple synthetic procedure has been used to prepare two new nickel(II) complexes [Ni-2(ttpy)(2)(SCN)(4)], (1) and [Ni(ttpy)(2)](CH3OH)(2) (2I), (2) from 4'-p-tolyl-2,2': 6',2"-terpyridine (ttpy) ligand, potassium thiocyanate, and potassium iodide in good yields. The single crystal X-ray analyses reveal that the metals in these complexes are sixfold coordinated with M:L ratio of 1:1 and 1:2 for (1) and (2), respectively. In both complexes, the Ni(II) has distorted octahedral geometry including N5S and N-6 environments. Versatile interactions in supramolecular level containing coordinative bonding, I center dot center dot center dot H, and N center dot center dot center dot H hydrogen bonding, pi-pi stacking play considerable roles in forming crystal packing of (1) and (2). From obtained data it is concluded that differences in coordination abilities, of used counterions, cause the formation of complexes with 1:1 or 1:2 ratio of metal and ligand. Electrochemical behaviors of the both complexes were investigated.