Multinuclear nickel(II) complexes with chiral schiff base ligand

Abstract Herein we report three chiral, hierarchal mono-, tetra-, and hexa-nuclear nickel complexes that were formed via controlled self-aggregation based on ancillary ligands H3L1 (2,6-bis[(2,3-dihydro-1H-2-indenol)imine]-4-bromophenol) and H3L2 (2,6-bis[(2,3-dihydro-1H-2-indenol)imine]-4-tert-butylphenol). Stoichiometric control of the metal precursor and ligand strongly influenced the nuclearity of the complexes. Mononuclear [Ni(H2L1)2Na2]·2ClO4(1) complex was obtained in the stoichiometric reaction of ligand H3L1 with nickel perchlorate in the presence of sodium acetate. Tetranuclear [Ni4(L1)2(µ3-OMe)2(µ1,3-OAc)2]·2Na(2) and hexanuclear [Ni6(L2)3(µ6-CO3)(MeOH)5(H2O)]·ClO4 (3) were selectively assembled by the reaction of nickel perchlorate and the ligand in a molar ratio of 1:2 without or with carbonate ions, respectively. The solid-state structures of the complexes were confirmed by single-crystal X-ray crystallography. The photophysical properties of the complexes were explored using UV-visible spectroscopy.