Unstable intermediates. Part LXIII. Radical anion AlH3– in γ-irradiated aluminium hydrides

Abstract

After exposure to γ-irradiation at 77°K lithium and sodium aluminium hydride and deuteride gave e.s.r. spectra consisting of six broad hyperfine features characteristic of the ²⁷Al nucleus. The magnitude of the isotropic coupling (ca. 223 G) and of the anisotropic coupling (ca. 30 G) are close to those expected for pyramidal molecules having bond angles ca. 110° and the unpaired electron strongly confined to aluminium. Any hyperfine coupling to the protons must be < ±20 gauss.