Sudhindra N. Misra

Intensity analysis of ƒ ↔ ƒ transitions and energy interaction parameters in studies of the structure of lanthanide haloacetates in solutions

Nine haloacetate complexes of Pr3+ and Nd3+ have been spectrophotometrically studied to study the structure of these complexes in solution state. The observed spectra in the visible region have been analyzed to calculate Slater-Condon, Lande, bonding and Judd-Ofelt intensity parameters. The degree of covalency in the bonding decreases in the order mono > di > tri halogen substituted complexes. In solution state the studied complexes are predominantly of ML species. All the complexes have nearly the same symmetry.

Spectroscopic studies of Nd(III) Schiff-base complexes

Abstract The Schiff base complexes of Nd(III) have been synthesized and characterized by analytical, magnetic, electronic and IR spectral studies. The values of Slater-Condon (Fk), Racah (Ek) interelectronic repulsion, Lande (ζ4f) spin-orbit interaction and oscillator strength (P), Judd-Ofelt (τλ) intensity parameters have been calculated. Using these parameters energies and intensity of ten levels in each of the six complexes in the region 360–1000 nm have been computed. The agreement between the computed and experimental values is good. The variation of all the parameters in the complexes from the corresponding Nd(III) free ion parameter has been discussed. Using F2 values, the nephelauxetic ratio β and bonding parameter b 1 2 have been calculated which infer the incidence of some covalent character of these complexes. The intensity of hypersensitive transition is found to increase with the increase of covalency. The IR spectra of the complexes have been recorded in the region 4000-400 cm−1. The assignments to different modes of vibrations and their shifts support the complexation.

ELECTRIC DIPOLE INTENSITY PARAMETERS FOR A SERIES OF STRUCTURALLY RELATED PRASEODYMIUM(m) AND NEODYMIUM(III) COMPLEXES AND UNUSUAL SENSITIVITIES OF SOME 4f-4f TRANSITIONS

347 INTRODUCTION 348 EXPERIMENTAL 350 RESULTS AND DISCUSSION 350 Unusual sensitivity of some non-hypersensitive transitions of Pr(III) and Nd(III): ligand mediated pseudohypersensitivity 351 Relative sensitivities of different 4f-4f transitions of Pr(III) and Nd(III) and their correlation with Judd-Ofelt intensity parameters 354 REFERENCES 360

A study of ternary complexes of praseodymium with cysteine and diols

Abstract Ternary complexes of praseodymium(III) with cysteine and diols (ethanediol; prop-1,2 diol; 2-butene-1,4 diol; but-2, 3 diol; pent-2, 4 diol and hex-1, 6 diol) of the type MAB, MA 2 B and MAB 2 have been synthesised and characterised by elemental analysis. The stability constants of these mixed ligand complexes have been calculated using alkalimetric titrations. The difference in the stability constants of binary and ternary complexes log K MAB , log K Ma 2 B and log K MAB 2 , and the constants log X MAB , log X MA 2 B and log X MAB 2 , were calculated and compared with the basicity of the ligand. The various spectral parameters have been computed from the absorption spectra of these complexes in alcoholic solutions. The magnitude of oscillator strength (P) and vb 2 have been correlated with the overall stability constants of various species.

Synthesis, spectral and magnetic studies of some mixed ligand complexes of spin-free cobalt(II)

Abstract The reactions of acetylacetone, methyl acetoacetate and ethyl acetoacetate derivatives of cobalt(II) with diamines and hydroxyquinoline have resulted in the isolation of hexacoordinated complexes of the stoichiometry Co(L) 2 (L′); where L = acetylacetone (AA), methyl acetoacetate (MeAA) or ethyl acetoacetate (EtAA) and L′ = ethylenediamine (En), propylenediamine (Pn) or 8-hydroxyquinoline. Their magnetic, IR and electronic spectral properties have been used to establish the stereochemistry. The values of the Racah interelectronic repulsion parameter (B) and crystal field splitting energy (10 Dq ) have been calculated using numerical as well as graphical procedures.

Double Trifluoracetates of Lanthanoids with Aluminium

Abstract Double trifluoroacetates of the type M[Al(OOCCF3)4]3 (where M = Pr, Nd, Sm, Gd, Tb, Dy, Ho and Er) have been prepared from the reactions of tris(diisopropoxy aluminium di-μ-isopropoxy) lanthanoid(III), (M[Al(OPri)4]3), with trifluoroacetic acid in benzene solution. The syntheses of these compounds have also been attempted by the reaction of anhydrous lanthanoid(III) trifluoroacetate and aluminium trifluoroacetate in the molar ratio 1:3 in trifluoroacetic acid. These crystalline derivatives dissolve freely in methanol, ethanol, dimethylformamide and water. Their properties and structures have been studied using elemental analyses and infrared spectra. The molar conductances of these derivatives in methanol show that they are as 1:1 electrolytes.

Synthesis and Spectral Studies of Monochloroacetates of Lanthanons

Abstract Nonochloroacetates of lanthanons (La, Ce, Pr, Nd and Sm) have been synthesized and characterized by elemental analysis, absorption and IR spectral data and the X-Ray powder patterns. Magnetic moments of these derivatives have been measured. Molecular weights, determined ebullioscopically in acetic acid, show these compounds to be dimeric. The shape of the hypersensitive band in the visible spectrum of the neodymium compound suggests that these compounds are nona-coordinated.