An Unprecedented Trinuclear Nickel(II) Complex Assembled from an Asymmetric Salamo-Type Ligand

Abstract

An unprecedented trinuclear Ni(II) complex assembled from an asymmetric Salamo-type ligand 6-ethoxy- 4′,6′-dichloro-2,2′-[(1,3-propylene)dioxybis(nitrilomethylidyne)]diphenol (H₂L) is synthesized. The Ni(II) complex with the general formula [Ni₃(L)₂(μ₃-OAc)₂]·3CH₃CN is characterized by IR, UV-vis, and fluorescence spectra and the single crystal X-ray analysis. All the Ni(II) atoms are hexacoordinated with slightly distorted octahedral symmetries. Interestingly, each Ni(II) atom is not located on the N₂O₂ cavity of the asymmetric Salamo-type (L)^2– unit, and two μ₃-OAc ions adopt an uncommon μ₃-η²:η¹ binding mode connecting the Ni1, Ni2, and Ni3 atoms. Furthermore, the crystallizing acetonitrile molecules successfully assemble into an infinite 2D network by hydrogen bonding and C–H···π interactions.