Infrared and electron spin resonance studies of the effect of γ-irradiation on [Cr(CN)5NO]3–, [Mn(CN)5NO]3–, and [Fe(CN)5NO]2– in alkali-metal halide host lattices

Abstract

I.r. and e.s.r. spectra of γ-irradiated [Cr(CN)₅NO]^3–, [Mn(CN)₅NO]^3–, and [Fe(CN)₅NO]^2– in alkali-metal halide host lattices are reported. New i.r. absorptions are attributed to species resembling [Cr(CN)₅NO]^{4–and 5–} and [Mn(CN)₅NO]^{2–and 4–}. There is e.s.r. evidence for the formation of [Mn(CN)₅NO]^2– and [Fe(CN)₅NO]^3– ions, but no feature attributable to [Cr(CN)₅NO]^5– or [Mn(CN)₅NO]^4– was detected. Possible reasons for this apparent contradiction are discussed. There was evidence for the metal ion in [Mn(CN)₅NO]^3– migrating though the lattice to sites where it could exist in the high-spin d⁵ form.