Theoretical Studies of Some Polymeric-Cu(II)-Pyrimidine-Carboxylate Ligands: Crystal Parameters and J Exchange Coupling

Abstract

In present study the experimental data of solids Cu(II)-Br-pyrimidine-2-carboxylate (1) (orthorhombic Pmc21) and Cu(II)-pyrimidine-4,6-dicarboxylate (2) (triclinic P1 -) were used to calculate their crystal parameters (a,b,c,α,β,γ) and the J exchange coupling constants of Cu-Cu interactions. The calculations were done employing the DFT method, using several density functionals for comparison. Keywords: DFT method, Spin exchange coupling, Crystal parameters.Asian Journal of Chemistry; Vol. 29, No. 12 (2017), 2739-2742 example of a uniform S = 1/2 antiferromagnetic Heisenberg chain with exchange parameter J = -12.5 cm -1

Theoretical calculation of the exchange coupling constant in some polymeric nickel(II) complexes using range-separated functionals

“…The analytical expression (Equation (1)) relating the susceptibility to the temperature for 1D Ni (II) polymers was first proposed by reference [2]. This is not the first time that two equations were used to fit the same experimental susceptibilities, by two different authors to give two different values of J [12]. Both values could be valid.…”

“…To do so, it requires greater computational resources, especially for large and moderately large molecules. Several attempts were done to estimate J in the literature [8,12,13]; some of them use simple DFT approach. In this study, we investigated the ability of some range-separated functionals hoping that they reproduce approximately experimental J and g values.…”