Alkali metal polyphosphides as intermediates in the synthesis of organophosphorus compounds from elemental phosphorus

Synthesis, Structure, and Electrochemical Properties of 2,3,4,5-Tetraphenyl-1-Monophosphaferrocene Derivatives

Heteroleptic 2,3,4,5-tetraphenyl-1-monophosphaferrocene [FeCp(η5-PC4Ph4)] was obtained at a 62% yield through the reaction of lithium 2,3,4,5-tetraphenyl-1-monophosphacyclopentadienide Li(PC4Ph4) (1) with [FeCp(η6-C6H5CH3)][PF6]. The structure of 1-monophosphaferrocene 2 and its W(CO)5-complex 3 were confirmed by multinuclear NMR and single-crystal X-ray diffraction study and further supported by DFT calculations. Cyclic voltammetry demonstrated that [FeCp(η5-PC4Ph4)] 2 has a quasi-reversible oxidation wave. The comparison of the properties of phosphaferrocene 2 with those of W(CO)5-complex 3 shows the possibility of changing the coordination type during oxidation.

Synthesis and electrochemical properties of 3,4,5-tris(chlorophenyl)-1,2-diphosphaferrocenes

A novel representative of sodium 3,4,5-triaryl-1,2-diphosphacyclopentadienide containing a chloro substituent in the meta-position of the aryl groups was obtained with a high yield based on the reaction of tributyl(1,2,3-triarylcyclopropenyl)phosphonium bromide and sodium polyphosphides. Further reaction of sodium 3,4,5-tris(3-chlorophenyl)-1,2-diphosphacyclopentadienide with [FeCp(η6-C6H5CH3)][PF6] complex gives a new 3,4,5-tris(3-chlorophenyl)-1,2-diphosphaferrocene. The electrochemical properties of 3,4,5-tris(3-chlorophenyl)-1,2-diphosphaferrocene were studied and compared to 3,4,5-tris(4-chlorophenyl)-1,2-diphosphaferrocene. It was found that the position of the chlorine atom on the aryl fragment has an influence on the reduction potential of 1,2-diphosphaferrocenes, while the oxidation potentials do not change.

Recent Breakthroughs in P4 Chemistry: Towards Practical, Direct Transformations into P1 Compounds

For several decades, academic researchers have been intensively studying the chemistry of white phosphorus (P4 ) in the hope of developing direct methods for its transformation into useful P-containing products. This would bypass the hazardous, multistep procedures currently relied on by industry. However, while academically interesting P4 activation reactions have become well established, their elaboration into useful, general synthetic procedures has remained out of reach. Very recently, however, a series of independent reports has begun to change this state of affairs. Each shows how relatively simple and practical synthetic methods can be used to access academically or industrially relevant P1 compounds from P4 directly, in "one pot" or even in a catalytic fashion. These reports mark a step change in the field of P4 chemistry, and suggest its possible transition from an area of largely academic interest to one with the promise of true synthetic relevance.