Electron spin resonance spectrum of tetraphenylarsonium tetra-chloro-oxochromate(V)

Abstract

The single-crystal e.s.r. parameters for [AsPh₄][CrCl₄O] giving g_∥ 2.006 ± 0.002 and g_⊥ 1.979 ± 0.002 are reported (where g_∥ coincides with the Cr–O direction). Solution measurements in CH₂Cl₂ give g 1.988 ± 0.001 and ā 18.1 × 10^–4 cm^–1, and the addition of excess of [NEt₄] Cl to these solutions results in an additional e.s.r. signal at g 1.970 ± 0.001 which is attributed to the [CrCl₅O]^2– species. The e.s.r. parameters have been interpreted using an ab initio molecular-orbital approach as well as the more conventional molecular-orbital approach. The results of these two approaches are critically compared.