Synthesis, Crystal Structures and Catalytic Property of Oxidovanadium(V) Complexes with N’-(4-Oxopentan-2-ylidene)nicotinohydrazide and 4-Bromo-N’-(4-oxopentan

Qiwen Yang,Yan Lei,Pu Wang

doi:10.17344/acsi.2020.5932

Abstract

A pair of structurally similar oxidovanadium(V) complexes with the general formula [VOLL’], with the hydrazone compounds N' -(4-oxopentan-2-ylidene)nicotinohydrazide (H 2 L 1 ) and 4-bromo- N' -(4-oxopentan-2-ylidene)benzohydrazide (H 2 L 2 ), and the acetohydroxamic acid (HL’) as ligands, have been synthesized and structurally characterized by physico-chemical methods and single crystal X-ray determination. Single crystal X-ray analysis indicates that the V atoms in the complexes are in octahedral coordination, with the ONO donor atoms of the hydrazone ligands, and the OO donor atoms of the acetohydroxamate ligands, as well as an oxido O atom. The complexes showed good property for the catalytic epoxidation of styrene.

Highlights

In recent years, due to the environmental and economic issues, green chemistry became the principle for chemical syntheses
The aldehyde- or ketone analogs in which the carbonyl group is replaced by an imine or azomethine group, are considered privileged ligands, because of their simple preparation in an one-pot condensation of aldehydes and primary amines in an alcohol solvent.[1]
The metal complexes of hydrazones have been widely studied for their structures, biological activities and catalytic properties.[2]

Summary

Introduction

Due to the environmental and economic issues, green chemistry became the principle for chemical syntheses. The aldehyde- or ketone analogs in which the carbonyl group is replaced by an imine or azomethine group, are considered privileged ligands, because of their simple preparation in an one-pot condensation of aldehydes (or ketones) and primary amines in an alcohol solvent.[1] The metal complexes of hydrazones have been widely studied for their structures, biological activities and catalytic properties.[2] Among the complexes, those with V centers are of particular interest for their biological and catalytic properties.[3] The epoxidation of alkenes is one of the most widely studied reactions in organic chemistry since epoxides are key starting materials for a wide variety of products. We report the syntheses, crystal structures and catalytic epoxidation properties of a pair of structurally similar oxidovanadium(V) complexes, [VOL1L’] (1) and [VOL2L’] (2), where L1 and L2 are the enolate form of N’-(4-oxopentan-2-ylidene)nicotinohydrazide (H2L1) and 4-bromo-N’-(4-oxopentan-2-ylidene)benzohydrazide (H2L2), respectively (Scheme 1), and L’ is the anionic form of acetohydroxamic acid (HL’).

Experimental

Results and Discussion

Conclusion