A Novel Trisamidophosphine Ligand and Its Group(IV) Metal Complexes

A novel trisamidophosphine ligand scaffold has been synthesized and employed to coordinate all of the group­(IV) metals. The resulting complexes feature closed half-cage geometries with the phosphorus donor and all three amides binding to the metal. Out of nine complexes of the type [PN3]­MX (M = Ti, Zr, Hf; X = NMe2, OTf, CH3), the zirconium derivatives have been studied by X-ray diffraction and shown to exhibit metal–phosphorus distances that are well in range of a coordinative bond. In contrast to its heavier homologues, the titanium methyl species [PN3]­TiMe is prone to thermally induced ligand CH activation with concomitant loss of methane.

本研究合成了一种新型三酰胺膦配体（trisamidophosphine ligand）骨架，并将其用于配位所有第IV族金属。所得配合物均具有闭合半笼状几何构型，其中磷供体与全部三个酰胺配体均与金属中心配位。在九种通式为[PN3]­MX的配合物（M为Ti、Zr、Hf；X为NMe2、OTf、CH3）中，锆基衍生物经X射线衍射（X-ray diffraction）表征后证实，其金属-磷键长均处于配位键的合理区间内。相较于其较重的同系物，钛甲基配合物[PN3]­TiMe易发生热诱导的配体CH活化反应，同时伴随甲烷脱除。