Synthesis, crystal structures and electronic properties of Schiff base nickel (II) complexes: Towards solvatochromism induced by a photochromic solute

We have synthesized and characterized two new nickel (II) complexes, bis(N-R-1-phenylethyl- or N-2-propyl-3,5-dichlorosalicydenaminato)nickel (II), which exhibit a thermally induced structural phase transition and negative solvatochromism. After UV light irradiation, we have successfully observed slight spectral changes in the π-π* region due to a conformational change of the chiral ligands caused by photochromic solute (4-hydroxyazobenzene) induced solvatochromism.