Publication in European Journal of Inorganic Chemistry

From Co(NO3)2·6H2O - NaN3 - abpt reaction system, a mononuclear complex [Co(abpt)2(N3)2] (abpt = 4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole) (1) and a dinuclear complex [Co2(abpt)µ-(abpt-H)2(N3)4]·1.12H2O (2) were obtained. The presence of neutral abpt, as well as azido ligands was proved by IR spectroscopy. X-ray crystallography shows that 1 is a molecular Co(II) complex with two azido ligands coordinated in trans-positions, while 2 is a dinuclear Co(III) complex bridged by two abpt-H ligands. p–p stacking interactions between pyridyl rings of abpt and N-H···N and C-H···N hydrogen bonds in 1 and 2 stabilize their structures by creating a 3D supramolecular network. The analysis of the magnetic properties of 1 revealed negative zero-field splitting parameter D = -24.1 cm-1 supported also by CASSCF/NEVPT2 and CASSCF/CASPT2 theoretical calculations. The X-band electron paramagnetic resonance also gives an evidence for a strong rhombic character of the anisotropy. The investigation of the ac susceptibility measurements identified 1 as a field-induced single-molecule magnet, in which direct, Raman and Orbach relaxation processes are present.

 

Date: 17. jan 2019 | Author: agch

Department of Inorganic Chemistry

Faculty of Science
Palacký University in Olomouc

17. listopadu 12
CZ-771 46 Olomouc
Czech Republic

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email : agch(at)upol.cz