The ligand mediated pseudohypersensitivity of the ³H₄ → ³P₂, ³H₄ → ³P₁, ³H₄ → ³P₀, and ³H₄ → ¹D₂ transitions of praseodymium(III) complexes in solution media

Abstract

SUDHINDRA N. MISRA and SHAUN 0 . SOMMEKER, Can. J. Chem. 70, 46 (1992). The absorption difference, comparative absorption spectrophotometry, and quantitative analysis of 4f-4f spectra of praseodymium (II1) and 3~, + transitions exhibit substantial intensification as well as a wide variation of oscillator strength. Since these transitions do not follow the selection rules they cannot be considered hypersensitive. Ligands such as P-diketones, Schiff bases, amino acids, diols, nucleic bases, nucleosides, nucleotides, alkoxides, and haloacetates with widely differing binding features in terms of coordinating ability, denticity, and normalized bite appear to induce, to varying degrees, high sensitivity in these non-hypersensitive transitions. The present article reports the high sensitivity of the ' H , + ' P 2 , ' P I , ' P O , and ID2 transitions of Pr(II1) by considering the solution spectra of 173 species. This unique sensitivity is termed Ligand Mediated Pseudohypersensitivity.

Bimetallic isopropoxides M[Al(OC3Hi7)4]3 (M = Pr, Nd)—catalyzed reduction of 2-octanone and benzophenone

“…We have also made similar observations during the spectral intensity data analysis for a number of complexes of varying structural features, binding abilities, and different compositional and conformational characteristics in solution and shown that minor changes due to these characteristics are accompanied by significant variation in the oscillator strength of different 4f -4f bands as well as remarkable variations in Judd-Ofelt (T λ ) parameters [38][39][40][41][42][43][44]. The present investigation, perhaps, is the first to report the MPV reduction of ketones using heterobimetallic isopropoxides, M[Al(-OC 3 H i 7 ) 4 ] 3 , as homogeneous catalysts.…”

Absorption spectral study for the interaction of Pr(III) with L-Aspartic acid in various aquated organic solvents through 4f-4f transition spectra: Analysis of reaction pathways and thermodynamic parameters

“…They however have shown significant sensitivity to minute changes in the coordination surroundings of Praseodymium(III). Hence, these non-hypersensitive transitions were named Pseudohypersensitive, and such findings were termed 'Ligand Mediated Pseudohypersensitivity' [28,29]. Absorption spectrophotometry is an extremely useful tool for lanthanide coordination chemistry, especially in solution and nonaqueous media, because most lanthanides have detailed internal f-electron transition spectra in the visible spectral region and are sensitive to the metal-ligand coordination environment.…”