The single-crystal electronic properties and stereochemistry of tri-potassium penta(nitro/nitrito)cuprate(II)

Abstract

The polarised single-crystal electronic and e.s.r. spectra of K₃Cu(NO₂)₅ have been determined and are shown to be consistent with the stereochemistry of the two non-equivalent copper(II) environments present namely, a seven-co-ordinate [CU(NO₂)₃(ONO)₂]^3– and a cis-distorted six-co-ordinate [CU(NO₂)₂(ONO)₂(ONO)]^3– species. The i.r. spectrum is shown to be compatable with the presence of nitro- and unidentate and bidentate nitrito-ligands, but cannot distinguish the two types of nitrito-co-ordination. A structural pathway is suggested between the seven-co-ordinate and cis-distorted species.