Reduction of (chloro)-μ-nitrido-bis[(tetra-tert-butyl-phthalocyaninato)iron(IV)] with organic N-bases

Abstract

The interaction of (chloro)-[Formula: see text]-nitrido-bis[(tetra-tert-butyl-phthalocyaninato)iron(IV)] Cl(FePc)2N with organic [Formula: see text]-bases L as electron–donors (L [Formula: see text] diethylamine, imidazole, 1-methylimidazole, 2-methylimidazole) with the formation of one-electron reduced species (L)PcFe[Formula: see text]–N[Formula: see text]Fe[Formula: see text]Pc(L) was investigated in benzene at 298 K by UV-visible spectroscopy. The reaction was established to be stepwise process including fast reversible axial binding of two substrate molecules onto iron cations followed by slow one-electron metal-centered reduction. The results of IR, ESI-MS and EPR study support the formation of final product with Fe[Formula: see text]–N[Formula: see text]Fe[Formula: see text] unit and two substrate molecules in the first coordination sphere. The reaction kinetics was studied, the pre-equilibrium constants [Formula: see text] and rate constants [Formula: see text] were obtained. The [Formula: see text] and [Formula: see text] values were found to be linearly correlated with basicity of substrates p[Formula: see text]. The possibility of the transition Fe[Formula: see text] Fe[Formula: see text] is promoted by electron–donor properties of substrate combined with the presence of both electron-rich macrocycle and [Formula: see text]-backdonation Fe [Formula: see text] N[Formula: see text].