Cocrystallization of binuclear iron(III) porphyrins with C60:: Bending of μ-O{FeIII(octaethylporphyrin)] and the first structure of the iron(III) octaethyloxophlorin dimer

Black crystals of C-60.mu-O{Fe-III(OEP)}(2).C6H6 and 2C(60).{Fe-III(OEPO)}(2).4C(6)H(6) suitable for single-crystal X-ray diffraction studies have been obtained by growth from benzene solutions of the appropriate binuclear metalloporphyrin and the fullerene. C-60.mu-O{Fe-III(OEP)}(2).C6H6 crystallizes with two molecules of mu-O{Fe-III(OEP)}(2), two fully ordered molecules of C-60, and two molecules of benzene in the asymmetric unit. Each independent molecule of mu-O{Fe-III(OEP)}(2) makes close contact with two fullerene molecules. In C-60.mu-O{Fe-III(OEP)}(2).C6H6 the Fe-O-Fe angles (150.18(11)degrees and 151.89(11)degrees) are markedly bent with a benzene molecule wedged into the opening between the two porphyrins, whereas in the triclinic and monoclinic polymorphs of mu-O{Fe-III(OEP)}(2) the Fe-O-Fe angles are more nearly linear (172.16(17)degrees and 176.2(2)degrees, respectively). The structure of 2C(60).{Fe-III(OEPO)}(2).4C(6)H(6) consists of a centrosymmetric {Fe-III(OEPO)}(2) molecule in which the two macrocycles are connected to one another through axial coordination of the meso-oxygen atoms to iron ions in the neighboring porphyrin. Each molecule of {Fe-III(OEPO)}(2) engages a fullerene on its two exposed faces. The basic geometry of the central core of {Fe-III(OEPO)}(2) is similar to that of the previously characterized {In-III(OEPO)}(2), but the distortion of the two macrocycles is greater in the former due to the shorter Fe-N and Fe-O bonds.