Two new mononuclear nickel (II) complexes incorporating Schiff base ligands, bis(N-R-1-phenylethyl- or N-2-propyl-3,5-dichlorosalicydenaminato)nickel (II), have been synthesized and characterized. The former chiral brown paramagnetic complex adopts a compressed tetrahedral [NiN 2 O 2 ] coordination geometry of Λ(R,R) absolute configuration with the coordination bond angles of N–Ni–N=116.3(2)° and O–Ni–O=141.4(2)°. On the other hand, the latter green diamagnetic complex adopts a square planar trans-[NiN 2 O 2 ] coordination geometry. It is revealed that flexible distortion of the [NiN 2 O 2 ] coordination environment and the overall dipole moment of the complexes are affected by both electronic withdrawing Cl-substituents and steric factors of the ligands. A structural phase transition occurs by heating in the solid state for both complexes. Negative solvatochromism relating to d–d and π–π* transitions can be observed, depending on the polarity of the solvents in which these complexes are dissolved. Furthermore, we have attempted to design a supramolecular solvatochromism system induced by a photochromic solute, that is a CHCl 3 solution of the chiral Ni(II) complex and polar 4-hydroxyazobenzene solute. After UV light irradiation, we have successfully observed slight spectral changes of the π–π* bands in absorption and CD spectra due to conformational change of the R-1-phenylethylamine moieties of the chiral ligands.