Molecular properties of coordination compounds of the croconate ion with first-row sivalent transition metals: a quantum mechanical study

Abstract

Neste artigo são relatadas geometrias, propriedades magnéticas e espectroscópicas de complexos de croconato [M(C5O5)(H2O)4] (M= Mn2+, Fe2+, Co2+, Ni2+, Cu2+ e Zn2+), calculados com Teoria do Funcional de Densidade. O estado fundamental de todos os complexos obtido foi de alto spin, em acordo com a proposta experimental. As estruturas e freqüências vibracionais calculadas também estão em acordo com o experimento, embora as comparações feitas sejam com estruturas do estado sólido. As propriedades ópticas não lineares (ONL) foram calculadas para todos os compostos analisados, usando o método Time Dependent Hartree-Fock (TDHF) dentro da abordagem estática, sugerindo que estes complexos de metais de transição possam ser utilizados no desenvolvimento de novos materiais baseados em moléculas.

In this paper we report geometries, magnetic and vibrational spectroscopic properties of croconate complexes [M(C5O5)(H2O)4] (M= Mn2+, Fe2+, Co2+, Ni2+, Cu2+ and Zn2+) calculated at the Density Functional Theory level. The ground state of all complexes was found to be of high spin, in accordance with the experimental proposal. The calculated structures and vibrational frequencies were also in agreement with experiment, even though comparisons were made with the solid state structure. The calculated nonlinear optical (NLO) properties were for all the compounds analyzed, using the Time Dependent Hartree-Fock (TDHF) method within the static approach, suggesting that these transition metal complexes might be considered as lead molecules to the development of novel based-molecular materials.