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

The zero-field, solid state, Fe-57 Mossbauer spectrum of the trinuclear high-spin iron(II) complex [Fe-3(SC(6)H2(t)Pr(3)-2,4,6)(4){N(SiMe(3))(2)}(2)] has been recorded at 77 K. 'Unusually large quadrupole splitting values(greater than or equal to 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.