Synthesis of Diruthenium Complexes Derived from Pyridyl-Substituted Indenes

Thermal treatment of the trinuclear ruthenium complex {μ2-η5:η1-(C5H4N)­(C9H5)}­Ru3(CO)9 (1) with 1,5-heptadiene, diallyl sulfide, 1,4-hexadiene, and 1,7-octadiene respectively generated the series of diruthenium products {(C5H4N)­(μ2-η5,η1-C9H5CHCH2CH2R)}­Ru2(CO)x (4, R = −CH2CH═CHCH3; 6, R = SCH2CH═CH2; 7, R = −CH═CHCH3; 8, R = −(CH2)3CH═CH2) via the insertion of an terminal C═C bond into the Ru–C­(η1) bond of 1. When 1 was treated with diallyl ether, the complex {(C5H4N)­(μ2-η5,η3-C9H5CCH2CH2OCCHCH3)}­Ru2(CO)4 (5) with a five-membered oxygen-containing heterocycle was produced. Reactions of 2-methyl-3-(2-pyridyl)­indene or 2,5-dimethyl-3-(2-pyridyl)­indene with Ru3(CO)12 gave the cycloruthenated complexes {(C5H4N)­(μ2-η5,η1-RC9H4CH2)}­Ru2(CO)5 (9, R = H; 10, R = CH3) with structures similar to those of 4, 7, and 8, via C­(sp3)–H activation. The molecular structures of 5–7 and 10 were determined by X-ray diffraction.