A Novel ZnII Complex Bearing Two Monodentate (4-Methoxyphenyl)[(1E, 2E)-3-phenylprop-2-en-1-ilidene] Schiff Bases: Crystal Structure and DFT Study

Giuliano M Cordeiro,Emanoel Hottes,Andressa Esteves-Souza,Carlos Maurício R De Sant’Anna,Marcelo H Herbst,Guilherme P Guedes

doi:10.1155/2019/7876495

Giuliano M Cordeiro, Emanoel Hottes + Show 4 more

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https://doi.org/10.1155/2019/7876495

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Abstract

A novel ZnII complex bearing two monodentate (4-methoxyphenyl)[(1E, 2E)-3-phenylprop-2-en-1-ilidene] Schiff bases was synthesized and investigated both in the solid state by single-crystal X-ray diffraction, elemental analysis, and FTIR and in solution by 1H NMR spectroscopy. The complex crystallizes in the P21/c monoclinic space group. The asymmetric unit contains one ZnII ion coordinated to two Schiff base ligands and two chloride ions, in a distorted tetrahedral geometry. The title complex was also investigated by DFT, using the hybrid functional B3LYP with basis set 6-31G++, which reproduced the geometry and structural features of the complex in the crystal, and was used to assign the main bands in the FTIR spectrum. In solution, the complex maintains its integrity against decomposition to the parent reagents.

Highlights

Schiff bases are important intermediates in many enzymatic reactions involving interactions between an enzyme and a substrate carbonyl group. ey are generally prepared by the condensation of primary amines with carbonyl compounds, for instance, aldehydes. e IUPAC classifies Schiff bases as compounds that present an imino (C N) moiety, in which a nonhydrogen radical is directly bonded to the nitrogen atom, given the R2C NR formula
Chigurupati et al [8] synthesized a new series of azomethine derivatives of β-phenyl acrolein. e imine used in this work, dubbed 4methoxy-N-(3-phenylallylidene)benzamine, synthesized by that new route, was screened for antibacterial activity against Gram-positive and Gram-negative bacteria, being active against P. aeruginosa and S. aureus
Chen et al [11] investigated bridge carbon 13C NMR shifts of a wide set of substituted cinnamyl anilines of the general type p-XC6H4CH@CHCH@NC6H4Yp, using those compounds as a probe to study the change of substituent effect in the Journal of Chemistry conjugated system. ey found that the change of the inductive effect and the conjugative effect on different bridge carbons is related to the bond number (m) from the substituent to the corresponding carbon

Summary

Introduction

Schiff bases are important intermediates in many enzymatic reactions involving interactions between an enzyme and a substrate carbonyl group. ey are generally prepared by the condensation of primary amines with carbonyl compounds, for instance, aldehydes. e IUPAC classifies Schiff bases as compounds that present an imino (C N) moiety, in which a nonhydrogen radical is directly bonded to the nitrogen atom, given the R2C NR formula. Schiff bases are important intermediates in many enzymatic reactions involving interactions between an enzyme and a substrate carbonyl group. Barta et al [9] found that the selective iron catalyzed direct monoalkylation of p-methoxyaniline with 2-phenyl-ethane-1-ol generated as an intermediate the imine used in this work. Chen et al [11] investigated bridge carbon 13C NMR shifts of a wide set of substituted cinnamyl anilines of the general type p-XC6H4CH@CHCH@NC6H4Yp, using those compounds as a probe to study the change of substituent effect in the Journal of Chemistry conjugated system. Bidentate imines are important ligands in coordination chemistry. Our objective was to investigate, both theoretically and experimentally, the coordination of the monodentate Schiff base (4-methoxyphenyl)[(1E, 2E)-3-phenylprop-2-en-1-ilidene] (Figure 1), for complexation with ZnII

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