Photochemisches verhalten von tricarbonyl-η 5:1-(2-cyclopentadiendiyl)ethyl-molybdän und -wolfram gegenüber cyclischen dienen

Abstract

Tricarbonyl-η 5:1-(2-cyclopentadiendiyl)ethyl-molybdenum ( 1) and -tungsten ( 2) were reacted photochemically with 1,3-cyclopentadiene ( A), 1,3-cyclohexadiene ( B), 1,3-cycloheptadiene ( C), norbornadiene ( D), 1,5-cyclooctadiene ( E), 2,3-dihydrofurane ( F), 1,3,5-cycloheptatriene ( G) and 1,3,5,7-cyclooctatetraene ( H). 1 reacts with A, B, D, E, and F to give the complexes [Mo(η 5:1-C 5H 4C 2H 4)(CO) 2(η 2-diene)] ( 3A, 3B, 3D, 3E, 3F) and [Mo(η 5:1-C 5H 4C 2H 4)(CO)(η 4-diene)] ( 4A, 4B, 4E). There is only spectroscopic evidence for the formation of the labile 1,3,5-cycloheptatriene complexes 3G and 4G. H inserts into the MoC bond to give [Mo(η 5:3-C 5H 4C 2H 4C 8H 8)(CO) 2] ( 5H). Complex 2 reacts similarly to give [W(η 5:1-C 5H 4C 2H 4)(CO) 2(η 2-diene)] ( 6A, 6B, 6C, 6G, 6G′, 6H), [W(η 5:1-C 5H 4C 2H 4)(CO)(η 4-diene)] ( 7A, 7B, 7C, 7G), and [W(η 5:3-C 5H 4C 2H 4C n H 8)(CO) 2] ( n = 7: 8G, n = 8: 8H). The crystal and molecular structure of 7B was determined by X-ray crystallography.