Preparation, Structure, Photoluminescent and Semiconductive Properties, and Theoretical Calculation of a Mononuclear Nickel Complex with 3-Hydroxy-2- Methylquinoline-4-Carboxylato Ligand

Xiao-Niu Fang,Qi Luo,Jia-Yi Chen,Yong-Xiu Li,Jia Li,Xiu-Guang Yi

doi:10.17344/acsi.2018.4885

Abstract

A novel nickel complex with mixed ligands [Ni(L)2(EtOH)2(MeOH)2] (HL = 3-hydroxy-2-methylquinoline-4-carboxylic acid) has been synthesized through solvothermal reaction and its crystal structure was determined by single-crystal X-ray diffraction technique. Single-crystal X-ray diffraction analyses reveals that the title compound crystallizes in the triclinic system of the P-1 space group, and exists as isolated mononuclear complex. The intermolecular hydrogen bonds lead to the formation of chains, and the layered supramolecular structure is formed by the strong ααααα stacking interactions. Solid-state photoluminescent characterization reveals that the title compound has an emission in the green region. Time-dependent density functional theory (TDDFT) calculation shows that the nature of the photoluminescence of the title compound originates from the ligand-to-ligand charge transfer (LLCT; from the HOMO of the p-orbital of ligand HMCA to the LUMO of the oxygen atoms). A wide optical band gap of 2.25 eV is found by the solid-state UV/vis diffuse reflectance spectrum.

Highlights

In recent years, metallo-organic coordination polymers have attracted considerable interest due to their diverse structures and potential applications in fluorescence, magnetic materials, gas adsorption, catalysis and medicine and so forth.[1,2,3,4,5,6] The synthesis of coordination polymers with specific functions has gradually become a research hotspot in the field of material chemistry.[7]
A novel nickel(II) complex [Ni(L)2(EtOH)2(MeOH)2] with the ligands of 3-hydroxy-2-methylquinoline-4-carboxylic acid (HL), MeOH and EtOH was synthesized by solvothermal synthesis, its structure and properties were investigated with infrared spectrum, elemental analysis, single-crystal X-ray, solid-state diffuse reflectance spectrum, photoluminescent and theoretical calculations
The title compound crystallizes in the triclinic system of the P–1 space group as isolated mononuclear complex

Summary

Introduction

Metallo-organic coordination polymers have attracted considerable interest due to their diverse structures and potential applications in fluorescence, magnetic materials, gas adsorption, catalysis and medicine and so forth.[1,2,3,4,5,6] The synthesis of coordination polymers with specific functions has gradually become a research hotspot in the field of material chemistry.[7]. Nitrogen heterocyclic compounds have attracted much attention due to their flexible coordination modes and easy coordination with metal ions. They are commonly used ligands for building complexes. A series of complexes based on these ligands have been reported.[11,12,13,14] But carboxyl groups have many coordination modes such as monodentate coordination, symmetrical chelation coordination, asymmetrical. 2019, 66, 414–420 chelation coordination, monooxy bridging coordination and so on, and have strong coordination ability They can coordinate with almost all metals to form complexes, and have a large number of unique structures and excellent properties. Its structure and properties were investigated with infrared spectrum, elemental analysis, single-crystal X-ray, solid-state diffuse reflectance spectrum, photoluminescent and theoretical calculations

Experimental

Results and Discussion

Conclusions