Unusual electronic structure of bis-isocyanide complexes of iron(iii) porphyrinoids

Abstract

A series of isocyanide complexes, [Fe(Porphyrinoid)(^tBuNC)₂]⁺, were synthesized and examined for their physicochemical properties. The molecular structure of the bis(^tBuNC) adduct of the iron(III) porphycene (1) and corrphycene (2) adopting the (d_xy)²(d_xz, d_yz)³ ground state were determined for the first time. Furthermore, 1 and 2 showed unusual crossover phenomena between different electron configurations, (d_xy)²(d_xz, d_yz)³ ground state and (d_xz, d_yz)⁴(d_xy)¹ ground state, by the addition of the external stimuli.