Electron spin echo study of neodymium(3+) solvation geometry in ethanol glasses. Disorientation of molecular dipoles in the first solvation shell

Abstract

Electron spin echo modulation (ESEM) studies have been carried out for Nd/sup 3 +/ in ethanol glasses at 4.2/sup 0/K. ESEM analysis of Nd/sup 3 +/ in CH/sub 3/CH/sub 2/OD indicates ninefold coordination of ethanol in the first solvation shell. By using the specifically deuterated ethanols CH/sub 3/CH/sub 2/OD, CH/sub 3/CD/sub 2/OH, and CD/sub 3/CH/sub 2/OH, ESEM analysis of deuterium modulation in three-pulse electron spin echo decay curves gives the distances to the various deuteron groups. These distances establish that the molecular dipole of ethanol is disoriented from Nd/sup 3 +/ by about 35/sup 0/. This contrasts with methanol solvation of Nd/sup 3 +/ where the methanol moleculr dipole is oriented toward Nd/sup 3 +/. The difference between methanol and ethanol solvation is attributed to steric interactions. 4 figures.