Electron spin resonance studies on some copper(II) complexes with a few nitrogen donors derived from pyridine
✍ Scribed by I.S. Ahuja; Shailendra Tripathi
- Publisher
- Elsevier Science
- Year
- 1991
- Tongue
- English
- Weight
- 406 KB
- Volume
- 47
- Category
- Article
- ISSN
- 1386-1425
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✦ Synopsis
Electron spin resonance spectral studies have been made on copper(I1) chloride, bromide, thiocyanate and sulphate complexes with some pyridine derivatives, viz. nicotinic acid (NA), nicotinamide (NICA) and isonicotinamide (INA) in solid and DMF-solution states to see the effect of different anions on the Spin-Hamiltonian parameters at the paramagnetic site for a particular l&and. The spectra of the complexes for a particular anion are almost comparable suggesting the same local symmetry for them. Analysis of the ESR data reveals axial symmetry for all the complexes, except Cu(NA)*S04 for which a rhombic symmetry is suggested. The study shows the interaction of solvent (DMF) molecules with copper(I1) ion in the axial plane as evident from the differences in 295 and 77 Kg,, values. Moreover, the spectra are consistent with the complete absence or negligbly small copper(II)-copper (II) interactions (in few cases) in these complexes. The various Spin-Hamiltonian parameters calculated from ESR data indicate the presence of an unpaired electron in the dXz_yzorbital of the copper(B) ion with the additional possibility of a d, ground state for Cu(NA),SO,.