An Unsymmetrical Trinickel Metal Complex with 4-Sulfobenzoate Axial Ligand: [Ni3(dpa)4(4-sb)(H2O)]×3H2O

Xiao-Feng Zheng,Long-Guan Zhu

doi:10.3390/cryst1030120

Abstract

An unsymmetrical trinickel metal complex, [Ni3(dpa)4(4-sb)(H2O)]×3H2O (1), where dpa is a 2,2’-dipyridylamine anion and 4-sb is 4-sulfobenzoate dianion, was synthesized and characterized by X-ray crystallography, IR, elemental analysis, fluorescence, and cyclic voltammetry. The molecular structure of 1 is a cluster with a linear trimer. The extended structure is a 3D architecture assembled by hydrogen bonds. The 4-sulfobenzoate axial replacement leads to the change of Ni-Ni distances, the shift of the fluorescence emission, and the reversible one-electron reduction process without oxidation process.

Highlights

30 trinickel metal complexes with 2,2’-dipyridylamine ligands have been prepared since 1991 [1]
Complex 2 was unexpectedly obtained from re-crystallization of [Ni3(dpa)4(CH3CN)2]](PF6)2 in dichloromethane [2]
Complex 3 was synthesized by control of the ratio of starting materials and reaction time [3]

Summary

Introduction

30 trinickel metal complexes with 2,2’-dipyridylamine (dpa) ligands have been prepared since 1991 [1]. Only two complexes with different axial ligands were reported,. [Ni3(dpa)4(CH3CN)](PF6)(2CH2Cl2) (2) and [Ni3(dpa)4(Cl)(ClO4)].CH2Cl2 (3) [2,3]. Complex 2 was unexpectedly obtained from re-crystallization of [Ni3(dpa)4(CH3CN)2]](PF6) in dichloromethane [2]. Complex 3 was synthesized by control of the ratio of starting materials and reaction time [3]. Crystals 2011, 1 ligands in trinickel complexes can largely influence the structural parameters and properties [4], for example complex 2 has an unusual magnetic property; synthesis of new unsymmetrical trinickel complexes can provide more examples to help understand the influence of structures on their properties. We report a new unsymmetrical trinickel complex with the 4-sulfobenzoate (4-sb) ligand, namely [Ni3(dpa)4(4-sb)(H2O)]⋅3H2O (1)

Results and Discussions

Materials and synthesis

Crystallographic determination

Conclusions