New metal-organic systems with a functionalized oxamate-type ligand and MnII, FeII, CuII and ZnII

Resumo

Four new complexes of formula [Fe(H2pcpa)2(H2O)2] (1), {[Mn(Hpcpa)(H2O)3]•1/2H2O}n (2), {[Zn(Hpcpa)(H2O)3]•1/2H2O}n (3) and [Cu2(Hpcpa)2(bipy)2]•8H2O (4) [H3pcpa=N-(4-carboxyphenyl) oxamic acid; bipy = 2,2′-bipyridine] have been synthesized and their structures determined by X-ray diffraction. The structure of 1 consists of mononuclear iron(II) units where each iron(II) ion is six-coordinate by two trans-positioned water molecules and two bidentate H2pcpa− ligands building a distorted octahedral environment. 2 and 3 consist of neutral zigzag chains of MnII and ZnII ions respectively, the Hpcpa2− groups acting as linkers in a bidentate/monodentate coordination mode with three mer-positioned water molecules achieving the six-coordination around the metal centers. Compound 4 is a neutral centrosymmetric dicopper(II) complex where two Hpcpa2− groups adopting the bidentate/monodentate coordination mode and act as bridges and bidentate bipy molecules act as end-cap ligands, describing a square pyramidal surrounding around each copper atom. Cryomagnetic measurements for 1, 2 and 4 in the temperature range 1.9-300 K reveal the occurrence of a field-induced single-ion magnet (SIM) behavior (1) and weak interchain (J = –0.22 cm–1, 2) and intradimer (J = –0.39 cm–1, 4) antiferromagnetic interactions, the Hamiltonian being defined as H = –J Sa . Sb.

Descrição

Palavras-chave

Iron(II), Manganese(II), Zinc(II), Copper(II), Oxamate, Magnetic properties, Singleion magnet

Citação

MACIEL, Jhonny W. et al. New metal-organic systems with a functionalized oxamate-type ligand and MnII, FeII, CuII and ZnII. Journal of the Brazilian Chemical Society, Campinas, v. 30, n. 11, p. 2413-2429, 2019. DOI: 10.21577/0103-5053.20190158. Disponível em: https://jbcs.sbq.org.br/default.asp?ed=291. Acesso em: 29 set. 2023.