Preparation and Molecular Structure of Binuclear Nickel (I) Complex Bridged by 1,2,4, 5‐Benzenetetracarboxylato Tetravalent Anion

The title complex (H₂O)₂(IMI)₃Ni(TCB)Ni(IMI)₃‐(H₂O)₂] H₂O (TCB = 1,2,4,5‐benzenetetracarboxylato te‐travalent anion; IMI = imidazole) has been prepared by the reaction of Ni(IMI)₃(Ac)₂ and TCB in aqueous solution. The crystal structure has been determined by single‐crystal X‐ray diffraction method. It crystallizes in the monoclinic system, space group P2₁/c(# 14), a = 1.2714(4) nm, b = 0.9411 (3) nm, c = 1.5869(4) nm, β= 108.54(2)°, V= 1.8001(9) nm³, Z = 2. The main feature of the crystal structure is a symmetric binuclear unit made up of two slightly distorted coordination octahedrons, which are bridged by TCB in monodentate fashion to each metal ion. Moreover three nitrogen atoms from three imidazoles, three oxygen atoms from two water molecules and one carboxylate group of TCB coordinated to a nickel (I) ion are found on a face of the octahedron respectively, so the octahedron is a facial isomer.