Estudo estrutural de complexos de cobre (II) como modelos de sítios metálicos de enzimas com atividade oxidativa
Carregando...
Data
2009-04-24
Autores
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Federal de Goiás
Resumo
We present the structural study, by x-rays diffraction, of two forms on the crystalline and molecular structures of the metal-organic single-crystal compounds Dicloro[N-
benzoyl-N´-(4-methylphenyl)-N´´-(2-pyridinyl)-guanidine)]copper(II). Such compound is known
for the phenol oxidative catalictic bioactivity. The compound is a copper(II)-guanidine de-
rivative complex. The main motivation of the present work is the polimorphism observed
on such complex when the crystallization conditions are changed. The structures were sol-
ved using the Direct Methods method and the structural parameters were refined with full
matrix least-squares method.
The copper(II) complex C19H22Cl2CuN4O crystallizes in the triclinic system in
the P¯1 space group, with a single molecule in the assymetric unit and unit cell parameters:
a = 8.616 (3) °A, b = 9.288 (3) °A, c = 13.623 (2) °A, α = 106.96 (2)o, β = 96.02 (3)o, γ
= 100.60 (2)o, with volume 1010.3 (5) °A3 and calculated density of 1.528 Mgm−3. The
same compound also crystallizes in the monoclinic system in the P21/n space group and
unit cell parameters: a = 7.937 (2) °A, b = 18.727 (2) °A, c = 13.993 (2) °A, β = 102.03
(2)o, with volume 2034.2 (6) °A3 and calculated density 1.518 Mgm−3. The two isomeric
molecules showed different conformations from one crystal packing to the other, due to the
different intermolecular interactions. Given the different crystal packing and intermolecular
interactions, we performed electronic structure calculations using the Density Functional
Theory in order to derive the energetic differences, including calculations of dimers linked
by hydrogen bonds, for evaluating the crystal packing influence on the complex stability in
their crystal structures.
Descrição
Citação
SOUSA JÚNIOR, Joel Padilha de. Structural study of complexes of copper (II) as models
metallic sites of enzymes with oxidative. 2009. 71 f. Dissertação (Mestrado em Ciências Exatas e da Terra) - Universidade Federal de Goiás, Goiânia, 2009.