Triple-bond reactivity of diphosphorus molecules

We report a mild method for generating the diphosphorus molecule or its synthetic equivalent in homogeneous solution; the P-2 allotrope of the element phosphorus is normally obtained only under extreme conditions (for example, from P-4 at 1100 kelvin). Diphosphorus is extruded from a niobium complex designed for this purpose and can be trapped efficiently by two equivalents of an organic diene to produce an organodiph'osphorus compound. Diphosphorus stabilized by coordination to tungsten pentacarbonyl can be generated similarly at 25 degrees C, and in this stabilized form it still efficiently consumes two organic diene molecules for every diphosphorus unit.