| Autor: |
Pal, Satyanarayan, Pushparaju, Jally, Sangeetha, Nimma, Pal, Samudranil |
| Zdroj: |
Transition Metal Chemistry; Oct2000, Vol. 25 Issue 5, p529-533, 5p |
| Abstrakt: |
Copper(II) complexes [CuL2] of pyridine-N, imine-N and amide-O donor Schiff bases (HL) are reported. The Schiff bases Hpabh, Hpamh and Hpadh were prepared by condensation of 2-pyridinecarboxaldehyde with benzhydrazide, 4-methoxybenzhydrazide and 4-dimethylaminobenzhydrazide, respectively. The complexes were synthesised in MeOH media by reacting Cu(OAc)2 · H2O with HL in a 1:2 mole ratio. The X-ray structure of [Cu(pabh)2] was determined. The rhombically distorted octahedral CuN4O2 coordination sphere is formed by two mononegative meridionally spanning pyridine-N, imine-N and deprotonated amide-O donor ligands. Electronic spectra of the complexes display two d–d bands at ca. 700 and ca. 1300 nm and two strong absorptions due to charge transfer transitions in the 450–268 nm range. Room temperature (298 K) solid state magnetic moments (1.90–2.08 μB) suggest an S = 1/2 spin state in each complex. The powder e.p.r. spectra of [Cu(pabh)2] and [Cu(pamh)2] at room temperature are consistent with a rhombic distortion of the N4O2 octahedron around the metal centre. However the spectrum of [Cu(padh)2] suggests a tetragonal elongation of the CuN4O2 octahedron. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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