Absorption Difference and Comparative Absorption Spectrophotometry of Neodymium(III) Haloacetates in Non-Aqueous Media and in Crystalline State

Abstract

Neodymium(III) haloacetates (monochloro-, dichloro-, trichloro- and trifluoro acetates) gave 1:3 adducts with alcohols, while yield mixed solvato complexes with dimethyl formamide and dimethyl sulphoxide of the type Nd(solv)_x (OOCR)₃ where x = 4 or 6 depending upon the time given for the reaction. Absorption difference and comparative absorption spectrophotometry were used to study the coordination geometry of metal ion in Nd(III) haloacetates both in crystalline and in non-aqueous (DMF, Methanol, Methanol-DMF, and Isobutanol-DMF equimolar binary mixtures) solvents. The computed values of spectral parameters and the variation of these parameters were used to supplement comparative absorption study.

The transitions ⁴I_9/2→⁴G_7/2, ⁴F_7/2, ⁴F_5/2 and ⁴F_3/2 and which have generally been regarded almost linsensitive towards coordination environment, have been found tp be substantially sensitive and thus been referred to as Pseudohypersensitive transitions and observation has been given the name “Ligand Mediated Pseudohypersensitivity”.