An extremely large 57Fe Mössbauer quadrupole splitting for a distorted tetrahedral high-spin iron(II) complex

Abstract

The zero-field, solid state, 57Fe Mössbauer spectrum of the trinuclear high-spin iron(II) complex [Fe 3(SC 6H 2 iPr 3−2,4,6) 4∗N(SiMe 3) 2∗ 2] has been recorded at 77 K. ‘Unusually’ large quadrupole splitting values (≥3.5 mm s −1) are observed for both the distorted trigonal planar (3.60 mm s −1) and distorted tetrahedral iron atoms (4.55 mm s −1) of the complex. The quadrupole splitting of the distorted tetrahedral iron atom is extremely large and equals that previously reported as the largest. ‘Unusually’ large quadrupole splittings for high-spin iron(II) are not that unusual and, in fact, are found for several coordination numbers and geometries.