Mössbauer Spectra of Some Tetrahedral Iron (II) Compounds

摘要: The 57Fe Mossbauer‐effect spectra of a series tetrahedrally coordinated Fe(II) compounds general formula R2FeX4 have been measured over wide temperature range. absorption showed approximately tenfold increase on cooling from 300° to 4.2°K, showing that the effective Debye for ion is low. isomer shifts (1.0–1.1 mm/sec relative iron) and quadrupole splittings (2.7–3.3 at 4.2°K) reflect degree covalency in anions their distortion cubic symmetry. was present all studied, dependent both upon ligand X cation R. For large cations variation splitting can be understood terms static which splits dz2 dx2—y2 states by an energy Δ, where, e.g., Δ=470 cm−1 R2=(N,N′‐dimethyl‐4,4′‐dipyridyl)++. (NMe4)2FeCl4 cannot accounted simply temperature‐independent field Δ. Measurements ...