Mononuclear dysprosium(III) complex exhibiting magnetic relaxation
Închide
Articolul precedent
Articolul urmator
997 10
Ultima descărcare din IBN:
2023-06-13 08:56
SM ISO690:2012
STAFI, Radu, SHOVA, Sergiu, NOVITSKY, Ghenadie, DRAGANCEA, Diana. Mononuclear dysprosium(III) complex exhibiting magnetic relaxation. In: Achievements and perspectives of modern chemistry, 9-11 octombrie 2019, Chişinău. Chisinau, Republic of Moldova: Tipografia Academiei de Ştiinţe a Moldovei, 2019, p. 145. ISBN 978-9975-62-428-2.
EXPORT metadate:
Google Scholar
Crossref
CERIF

DataCite
Dublin Core
Achievements and perspectives of modern chemistry 2019
Conferința "International Conference "Achievements and perspectives of modern chemistry""
Chişinău, Moldova, 9-11 octombrie 2019

Mononuclear dysprosium(III) complex exhibiting magnetic relaxation


Pag. 145-145

Stafi Radu1, Shova Sergiu2, Novitsky Ghenadie3, Dragancea Diana1
 
1 Institute of Chemistry,
2 “Petru Poni” Institute of Macromolecular Chemistry,
3 Joseph Fourier University
 
Disponibil în IBN: 7 noiembrie 2019


Rezumat

Lanthanides, thanks to their large ground-state spin and intrinsic magnetic anisotropy, are promising candidates for applications in the design of magnetic material. It is known that 2,6diacetylpyridine is an excellent precursor for the synthesis of planar pentadentate ligands, thus promoting the formation of complex compounds with a rigid pentagonal-equatorial plane and with kinetically labile coordinating ligands at the apical sites. Herein a mononuclear complex [Dy(H2L)(MeOH)(H2O)(NO3)](NO3)2·H2O (1), which is obtained from the reaction of Dy(III) nitrate and 2,6-diacetylpyridine bis(isonicotinoylhydrazone) is reported. Complex 1 was characterized by IR spectroscopy and single crystal X-ray crystallography. A strong band at 1663 cm–1 in the IR spectrum of the ligand H2L was shifted to 1635 cm –1 and decreased in intensity, which may be the result of the C = O bond elongation and the coordination of the oxygen atom. The behaviour of the absorption band v(NH), which is observed in the ligand spectrum at 3184 cm –1 , could not be observed due to the very high intensity bands assigned to the v(OH) absorption of the CH3OH and H2O coordinated molecules. The band at 1591 cm –1 attributed to the v (C = N) vibration of the ligand is also shifted to lower energy in the complex (1549 cm –1 ), indicating coordination of the nitrogen atom of the azometine bond. Single-crystal X-ray analysis revealed that the asymmetric unit of [Dy(H2L)(MeOH)(H2O)(NO3)](NO3)2·H2O (Figure) consists of the DyN3O2 entity in which the neutral pentadentate ligand H2L coordinates through the pyridine nitrogen atom, the hydrazonic nitrogen atoms and both oxygen atoms of the amide groups. The analysis of bond lengths in the –NH–C(=O)– fragment shows that the electrons from the deprotonation of the amido group are delocalized and form a conjugated system, and the two protons are attached to the nitrogen atoms of the pyridine ring. The Dy(III) ion is nine-coordinate due to bonded water and methanol molecules, and bidentate nitrate ion. Two nitrate ions in the outer sphere compensate the double charge of complex cation. Magnetic AC measurements have shown that Dy(III) complex 1 exhibits two maxima of "out-of-phase" susceptibility. This observation is the sign of a slow relaxation of magnetism, and is often called field-induced SMM behaviour.