Nanocrystalline samples of Cd 1Àx Mn x O (x ¼ 0.00, 0.02, 0.04 and 0.06) were synthesised by sol-gel method and characterised by X-ray diffraction, Faraday's rotation, Guoy's method and electron paramagnetic resonance (EPR) at room temperature (RT). Results reveal that ferromagnetism at RT for Mn-doped CdO nanoparticles is possible.

Theoretical calculation on the phonon dispersion of CdO nanoparticles at room temperature is reported here for the first time. The mean square amplitude, Debye-Waller factor and Debye temperature are calculated for CdO nanoparticles from the phonon spectrum and compared with the experimental results obtained from Rietveld refinement of XRD pattern of the CdO nanoparticles. The thermal stability of the nanoparticles is studied from both the experimental and theoretical calculations of melting point which is found to be 3686 K and 3951 K, respectively, greater than that of bulk CdO.

Nickcl(II) complcxes @ I i i of tridentate Schiff bases (HL) containing amide functionality are dcscribod. The schiff k, Hpabh and Hpamh (H refers to the dissociable ami& proton), arc derived ftom 2-pyridineCarbo Xaldehyde and benzhydrazide, and 2-pyridinccarbo xaldehydc and 4methoxybenzhydrazidc. respectively. The readion of two equivalents of HL and one equivalent of Ni(o2ccH,)2 -4H20 in methanol affords piq in high yield. The complexes are charactcriaad by analytical, spectroscopic, magnttic and elcctrochdcal techniques. The struchucs of both complcxcs have bcm determined by X-ray crystallography. The distorted octahedral Nii4O2 sphere in each complex is assembled by the two meridional N,N.Odonor ligands. Each ligand binds the metal ion via the pyridinc-N, imine-N and deprotonated amide-0 atoms. The solid state room temperature (298 K) magnaic moments are consistent with a d' (S-1) ground state electronic configuration. Electronic spcctra of the complexes in CH3CN solutions display the v, band at N 850nm followed by charge transfer bands in the range 381-241 nm. The mmLJ+-[NinLJ couple WBS observed in the cyclic voltammograms of both compltxes. TIE potentials arc 0.97 and 0.91 V (versus Ag-A@) for wi(pabh)d and wi(pamhM, respectively.

Manganese(I1) complexes of terdentate N,N,O donor Schiff bases (HL) are described. The ligands Hpabh, Hpamh and Hpadh are obtained by condensing 2-pyridine-carboxaldehyde with benzhydrazide, 4-methoxybenzhydrazide and 4-dimethylaminobenzhydrazide, respectively. The reaction of HL with manganese@) acetate tetrahydrate affords [MnL2J. The crystal structure determination of [Mn(pabh)z] was performed. T$e complex crystallises in the spaceo roup PZ,/n with a=9.836(3), b=23.994(7), c = 10.222(3)A, p= 104.14(3)", V=2339.5(13)A and Z = 4 . In the distorted octahedral MnN402 coordination sphere each ligand acts as a meridional N,N,O donor utilising pyridine-N, imine-N and amide-0 atoms. Electronic spectra of the complexes display charge transfer bands in the range 404-298 nm. Room temperature solid state magnetic moments (5.88-6.12~~) of the complexes are consistent with a high-spin dS system. EPR spectra of the complexes suggest a similar distorted octahedral N4O2 coordination sphere around Mn(I1) in each complex.9

No abstract