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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

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

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Author(s):
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]
Total Authors: 9
Affiliation:
[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
Total Affiliations: 4
Document type: Journal article
Source: European Journal of Inorganic Chemistry; n. 3-4, SI, p. 477-484, JAN 31 2018.
Web of Science Citations: 2
Abstract

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)

FAPESP's process: 15/22379-7 - Multifunctional molecular magnetic systems: synthesis and study of magnetic, luminescent and photorreactive properties of polinuclear complexes containing transition and lanthanide metal ions
Grantee:Wdeson Pereira Barros
Support type: Regular Research Grants