Details

Autor(en) / Beteiligte

• Simões, Tatiana R. G
• do Pim, Walace D
• Metz, Karina C
• Ribeiro, Marcos A
• Valente, Daniel C. A
• Cardozo, Thiago M
• Pinheiro, Carlos B
• Pedroso, Emerson F
• Horta, Bruno A. C
• Pereira, Cynthia L. M
• de Souza, Gilmar P
• Stumpf, Humberto O

Titel

Dinuclear copper() complexes containing oxamate and blocking ligands: crystal structure, magnetic properties, and DFT calculations

Ist Teil von

• New journal of chemistry, 2020-02, Vol.44 (6), p.2597-268

Ort / Verlag

Cambridge: Royal Society of Chemistry

Erscheinungsjahr

2020

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Three dinuclear copper( ii ) complexes containing oxamate-based ligands with the chemical formula [Cu( o pba)Cu(dap)(H 2 O)]·H 2 O ( 1 ), [Cu( o pba)Cu(dap-OH)(H 2 O)]·1.5H 2 O ( 2 ), and [Cu( o pba)Cu(en)(H 2 O)]·4H 2 O ( 3 ) in which o pba = o -phenylenebis(oxamato), dap = 1,3-diaminopropane, dap-OH = 2-hydroxy-1,3-diaminopropane and en = ethylenediamine have been synthesized and their crystal structures have been determined by single crystal X-ray diffraction. The molecular structures of 1-3 consist of neutral dicopper( ii ) complexes obtained by the "complex as a ligand" strategy, in which each [Cu( o pba)] 2− fragment acts as a bidentate ligand towards the copper( ii ) ion bonded to the amine capping ligands (dap, dap-OH and en) and the two other carbonyl groups are uncoordinated. Variable-temperature magnetic susceptibility measurements of 1-3 in the temperature range of 4-300 K reveal a strong antiferromagnetic coupling between the metal centers through the oxamate bridge with J = −183.5 cm −1 ( 1 ), J = −195.8 cm −1 ( 2 ), and J = −195.6 cm −1 ( 3 ). The fit of the variable-temperature magnetic susceptibility data of 3 revealed that Cu II Cu II Cu II Cu II coupling between the dinuclear entities is very weak. In all cases, the Hamiltonian used was H = −JS 1 · S 2 . DFT calculations based on the broken-symmetry formalism were used to provide further insight and an explanation for the reported behavior. Dicopper( ii ) complexes were prepared as promising platforms for the design of polynuclear systems providing an avenue toward new molecule-based materials.