Hexanitrometallates. Part III. Electron transfer spectra

Abstract

In the complexes A₂A′M(NO₂)₆ the region 20–30 × 10³ cm^–1 shows a variety of transitions depending on A,A′ and M, in addition to (d–d) transitions of M. If the M–N bond is weak and M is not oxidizable or reducible the internal transitions of NO₂^– occur, hardly perturbed from those in NaNO₂. If M is Ce^III, Bi^III, or Pb^II electron transfer [(NO₂^–)₆â†� M] occurs. When A or A′ include Tl^I, Ag^I, or Pb^II and M is optically reducible (Co^III, Co^II, Fe^II, Ni^II, or Cu^II) one transition (M â†� A,A′) is observed. [M â†�(NO₂^–)₆] transitions are seen when M is optically reducible. Electron transfer transitions (NO₂^–â†� A,A′) are not observed. In Cs₂CdCd(NO₂)₆ doped with Co^III and Pb^II, which both occupy the M site, no (Co^IIIâ†� Pb^II) electron transfer is observed.