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Crystal Structure and Magnetic Properties of an Oxamato-Bridged Heterobimetallic Tetranuclear [(NiCuII)-Cu-II](2) Complex of the Rack Type

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Autor(es):
Reis, Natalia V. [1] ; Barros, Wdeson P. [2, 1] ; Oliveira, Willian X. C. [1] ; Pereira, Cynthia L. M. [1] ; Rocha, Willian R. [1] ; Pinheiro, Carlos B. [3] ; Lloret, Francesc [4] ; Julve, Miguel [4] ; Stumpf, Humberto O. [1]
Número total de Autores: 9
Afiliação do(s) autor(es):
[1] Univ Fed Minas Gerais, Dept Quim, Av Antonio Carlos 6627, BR-31270901 Pampulha, MG - Brazil
[2] Univ Estadual Campinas, Inst Quim, Caixa Postal 6154, BR-13083970 Campinas, SP - Brazil
[3] Univ Fed Minas Gerais, Dept Fis, Av Antonio Carlos 6627, BR-31270901 Pampulha, MG - Brazil
[4] Univ Valencia, Inst Ciencia Mol ICMol, Dept Quim Inorgan, C Catedratico Jose Beltran 2, Valencia 46980 - Spain
Número total de Afiliações: 4
Tipo de documento: Artigo Científico
Fonte: European Journal of Inorganic Chemistry; n. 3-4, SI, p. 477-484, JAN 31 2018.
Citações Web of Science: 2
Resumo

This work discusses a new heterobimetallic nickel(II)copper-(II) complex of the formula {[}Ni(tpa) Cu(opba)](2)center dot 6H(2)O (1) [H(4)opba = N, N'-1,2-phenylenebis(oxamic acid) and tpa = tris(2-pyridylmethyl)amine]. The molecular structure of 1 consists of neutral tetranuclear species with a 4R rack-type architecture featuring two (NiCuII)-Cu-II dinuclear units connected through two out-of-plane oxo(carboxylate-oxamate) atoms from the opba ligands. The crystal packing of 1 exhibits a supramolecular 1D arrangement of tetranuclear entities connected by hydrogen bonds and pi-pi stacking interactions. The dc magnetic properties of 1 were interpreted according to its dimer-of-dimer structure; the spin Hamiltonian being defined as [H = -J{[}S-Ni1 center dot S-Cu1 + S-Ni1i center dot S(Cu1)i - j(eff)(S-Cu1 center dot S-Cu1i)]]. The analysis of the magnetic data shows the occurrence of a strong intradimer antiferromagnetic coupling between the Ni-II and Cu-II ions {[}J = -115.2(4) cm(-1)] and a weak interdimer antiferromagnetic coupling between the Cu-II ions {[}j(eff) = -1.12(7) cm(-1)]. DFT-type calculations were performed to visualize the exchange pathway through the oxamate bridge and substantiate the value of J. (AU)

Processo FAPESP: 15/22379-7 - Sistemas magnéticos moleculares multifuncionais: preparação e estudo das propriedades magnéticas, luminescentes e fotorreativas de complexos polinucleares contendo íons metálicos de transição e lantanídeos
Beneficiário:Wdeson Pereira Barros
Linha de fomento: Auxílio à Pesquisa - Regular