Synthesis and Characterization of Hydride−Alkynyl, Allenylidene, Carbyne, and Functionalized-Alkynyl Complexes Containing the [Os(η5-C5H5)(PiPr3)2]+ Fragment: The Complex [Os(η5-C5H5)(CCCPh2)(PiPr3)2]PF6, a New Type of Allenylidene Derivative from the Reactivity Point of View | Publicación