Synthesis, structure, and reactivity of novel iron(II) complexes with a five-membered chelate ligand κ 2( Si, N)-SiMe 2O(2-C 5H 4N)

Abstract

Photolysis of Cp′(CO) 2FeSiMe 2O(2-C 5H 4N) ( 1a: Cp′=η 5-C 5H 5 (Cp), 1b: Cp′=η 5-C 5Me 5 (Cp*)) afforded Cp′(CO)Fe[κ 2( Si, N)-SiMe 2O(2-C 5H 4N)] ( 2a: Cp′=Cp, 2b: Cp′=Cp*) in good yield each. These cyclic compounds also formed in moderate yields through photoreaction of Cp′(CO) 2FeSiMe 3 with HSiMe 2O(2-C 5H 4N) ( 3). Single-crystal X-ray diffraction study confirmed the structure of 2b containing a five-membered chelate ring comprised of Fe, Si, O, C, and N. Complexes 2a and 2b were thermally stable and did not react with slight excess of PR 3 (R=Me, Ph) in benzene- d 6 solution below 80 °C. Above 80 °C, 2a reacted slowly with PR 3 to give Cp(CO)(PR 3)FeSiMe 2O(2-C 5H 4N) ( 6: R=Me, 7: R=Ph) accompanied by the cleavage of the FeN bond. These results indicate that both FeSi bond and FeN bond in 2 are notably sturdy.