Synthesen,spektroskopische Eigenschaften und Kristallstrukturen zweikerniger homo- und heteroleptischer μ-Carbido-Komplexe von Eisen(IV) mit Phthalocyaninat- und Tetraphenylporphyrinat-Liganden

Syntheses, Spectroscopical Properties, and Crystal Structures of Binuclear Homo- and Heteroleptic μ-Carbido Complexes of Iron(IV) with Phthalocyaninate and Tetraphenylporphyrinate ligands μ-Carbidophthalocyaninato(2–)iron(IV)tetraphenylporphyrinato(2–)iron(IV) ( 2 ) and μ-carbido-bis(tetraphenylporphyrinato(2–)iron(IV)) ( 1 ) are synthesized by the reaction of phthalocyaninato(2–)ferrate(I) with dichlorcarbenetetraphenylporphyrinato(2–)iron(II). 1 and 2 as well as μ-carbido-bis(phthalocyaninato(2–)iron(IV)) ( 3 ) are soluble in tetrahydrofuran, but only 2 and 3 form solvent adducts 2 a and 3 a by coordination of thf to each of the iron atoms in trans position to the bridging C atom. The crystal structures of the solvates 1 · thf, 2 a · thf and 3 a · thf, crystallizing from the thf solutions, are determined: 1 · thf, orthorhombic, Fddd, a = 21.966(3) Å, b = 22.300(1) Å, c = 31.220(3) Å, Z = 8; 2 a · thf, orthorhombic, P22₁2₁, a = 14.487(3) Å, b = 20.753(5) Å, c = 25.803(7) Å, Z = 4; 3 a · thf, orthorhombic, P2₁2₁2₁, a = 12.642(1) Å, b = 22.361(7) Å, c = 23.629(3) Å, Z = 4. In all three double-decker complexes both ”︁tetrapyrrol”︁”︁ ligands are held together by a linear Fe–C–Fe bridge in a staggered ( 1 · thf, 3 a · thf) or ecliptic conformation ( 2 a · thf). The Fe–C distances vary between 1.71 and 1.64 Å (average: 1.68 Å). In 2 a · thf and 3 a · thf the iron atoms are nearly in the centre (Ct) of the (N_p)₄ planes (d(Fe–Ct) ∼ 0.1 Å), but in 1 · thf these atoms are directed by 0.27 Å towards the bridging C atom. The macrocyclic ligands of 1 · thf are severely concavely, those of 2 a · thf and 3 a · thf slightly distorted. The electronic absorption spectra and vibrational spectra are discussed.