Thermolytic Products Derived from Thermolysis of Cycloolefin-Coordinated Diiron Bridging Carbene Complexes

Abstract

Heating a benzene solution of the COT-coordinated diiron bridging alkoxycarbene complexes [Fe2{μ-C(OC2H5)Ar}(CO)4(η8-C8H8)] (1, Ar = C6H5; 2, Ar = p-CH3C6H4; 3, Ar = p-CF3C6H4) in a sealed tube at 85−90 °C for 72 h gave the bicycloolefin-coordinated tricarbonyliron dimers [Fe{η4-C9H8(Ar}(CO)3]2 (10, Ar = C6H5; 12, Ar = p-CH3C6H4; 14, Ar = p-CF3C6H4) and bridging arylcarbene complexes [Fe2{μ-C(H)Ar}(CO)4(η8-C8H8)] (11, Ar = C6H5; 13, Ar = p-CH3C6H4; 15, Ar = p-CF3C6H4). A similar thermolysis of 7H-indene-coordinated diiron bridging alkoxycarbene complex [Fe2{μ-C(OC2H5)C6H5}(CO)4(η4,η4-C9H8)] (4) yielded the ring addition product [Fe2{C(OC2H5)C6H5(η2,η5-C9H8)}(CO)5] (16). The 7H-indene-coordinated diiron bridging arylthiocarbene complexes [Fe2{μ-C(Ar)SC6H4CH3-p}(CO)4(η4,η4-C9H8)] (8, Ar = C6H5; 9, Ar = p-C6H5C6H4) were heated similarly to afford the isomerized 7H-indene-coordinated diiron bridging carbene complexes with a μ-SC6H4CH3-p ligand, [Fe2{μ-C(Ar)(η2,η5-C9H8)}(μ-SC6H4CH3-p)(CO)3] (17, Ar = C6H5; 19, Ar = p-C6H5C6H4), and the acyliron compounds [Fe(CO)2(CO){C(H)Ar(η5-C9H8)}] (18, Ar = C6H5; 20, Ar = p-C6H5C6H4). The structures of complexes 14, 16, 17, and 18 have been established by X-ray diffraction studies.