Ionic compound containing iron phthalocyanine (FeIPc)− anions and (C70−)2 dimers. Optical and magnetic properties of (FeIPc)− in the solid state

Abstract

Ionic compounds containing the anion of iron phthalocyanine (Fe(I)Pc)(-), {(Fe(I)Pc)(-)}·(cryptand[2,2,2]·[Na(+)])·(C(6)H(4)Cl(2)) (1), and the fullerene C(70)(-) and Fe(I)Pc(-) anions, (C(70)(-))(2)·{(Fe(I)Pc)(-)}(6)·(cryptand[2,2,2]·[Na(+)])(8)·(C(6)H(4)Cl(2))(8.65)·(C(6)H(14))(0.35) (2), were obtained as single crystals. Their crystal structures and optical and magnetic properties were analyzed. Spectra of 1 and 2 manifest intense bands in visible-NIR range at 820, 690, 555, 528, 449, 400 and 316 nm attributed to (Fe(I)Pc)(-). The four-coordinate (Fe(I)Pc)(-) anions show an EPR signal with perpendicular and parallel components at g(⊥) = 2.487 and g(‖) = 2.353 in 1 and g(⊥) = 2.328 and g(‖) = 2.230 in 2. According to magnetic measurements the (Fe(I)Pc)(-) anions have low spin (S = 1/2) state indicating d(7) configuration for the Fe(I) atoms with the odd electron on the d(z(2)) orbital. Fullerene anions form singly bonded (C(70)(-))(2) dimers in 2, the shape of which efficiently fitted with the large planar phthalocyanine anions to be surrounded completely by eight (Fe(I)Pc)(-) anions. The (C(70)(-))(2) dimers are diamagnetic and EPR silent up to 350 K. Both complexes contain channels formed by four (Fe(I)Pc)(-) planes in 1 or four (Fe(I)Pc)(-) planes and two (C(70)(-))(2) dimers in 2. The channels are occupied by double chains of alternating cryptand[2,2,2]·[Na(+)] cations and solvent C(6)H(4)Cl(2) molecules.