Vibrational, electronic, and Mössbauer spectra of some complexes of iron(II) with tri- and di-2-pyridylamine

Abstract

Complexes of tri-2-pyridylamine with ferrous perchlorate, chloride, and bromide are shown to contain the spin-paired bis(tri-2-pyridylamine)iron(II) cation. The first spin-allowed d↔d(¹T_1gâ†�¹A_1g) transition is assigned at 19,000 cm.^–1. Mössbauer data show the microsymmetry of the FeN₆ array in this cation to be cubic (ΔE_Q= 0·00) and also, together with other data, demonstrate the ferrous chloride complex to be Fe(tripyam)₂FeCl₄. The nature of the recently reported di-2-pyridylamine complexes Fe(dipyam)₂Cl₂,2H₂O and Fe(dipyam)₂Br₂ is confirmed and the detailed stereochemistry of the tris-(di-2-pyridylamine)iron(II) ion is briefly discussed.