First Example of the η 3-Prop-2-ynyl Ligand; Synthesis and Reactivity of Cationic (η 3-Prop-2-ynyl)arenedicarbonylmolybdenum Complexes; X-Ray Structure of [ Mo ( CO ) 2 ( η 6 - C 6 M e 5 H ) ( η 3 - HCCC H 2 ) ] + B F 4

A series of (η 3-prop-2-ynyl)arenedicarbonylmolybdenum complexes with a novel η 3-prop-2-ynyl ligand have been obtained, their structure has been established unambiguously by an X-ray diffraction study of a pentamethylbenzene derivative; the reactions of the η3-prop-2-ynyl derivatives with H 2O and PPh 3 yield complexes with 2-hydroxyallyl, 2-triphenyl phosphonioallyl and 1-triphenylphosphoionallene ligands.