Estudo molecular e supramolecular de complexos triazenidos com metais de transição: uma abordagem voltada à engenharia de cristais

Abstract

This work shows the synthesis of unpublished Zn(II), Cd(II) and Pd(II) complexes with bis-cated triazene molecules, including macrocycles. Together these compounds, a series of symmetrical ortho-halogenated single-catenad Au(I) triazenide complexes, previously synthesized by Zambiazi (2013), were used with the main purpose of evaluating the pendulum effect that the halogen substituents provoke on the linear coordination geometry of the N1– AuPPh3 fragment, as a consequence of the intramolecular interactions, besides the studies of the intermolecular interactions such as Halogen···Halogen and Halogen···π approaching the supramolecular cluster as delimitation of the crystalline arrangement. The macrocyclic complexes were evaluated by the triad of parameters (geometric, energetic and topological) with the objective of proposing crystallization mechanisms through retrocrystallization, besides the evaluation of the effect of the crystallization solvent present in compounds 6·Py, 7·Py and 8·Py to understand the consequences and importance that these solvates cause to the crystalline packaging. The acyclic bis-triazenide complexes of Pd(II) with different spacers between the triazoalilic chains (1,4-butyl fragment in compound 9 and 2,6-pyridyl fragment in compound 10) were compared on their different modes of coordination to the metal center. Compound 9 showed the expected lantern effect while compound 10 showed an unusual coordination of the central nitrogen atom of the triazenide chain. Both compounds were also analyzed through the topological approach in order to understand the stability of their molecular models and proposition of the crystallization mechanism of each compound.