Fragmentation Mechanism of White Phosphorus: A Theoretical Insight into Multiple Cleavage/Formation of P-P and P-C Bonds

Molecular-level understanding of metal-mediated white phosphorus (P-4) activation is meaningful but challenging because of its direct relevance to the conversion of P(4)into useful organophosphorus compounds as well as the complicated and unforeseeable cleavage process of P-P bonds. The related study, however, has still rarely been achieved to date. Here, a theoretical insight into the step-by-step process of three P-P bond cleavage/four P-C bond formation for [P-3+P-1]-fragmentation of P(4)mediated by lutetacyclopentadienes is reported. The unique charge-separated intermediate and the intermolecular cooperation between two lutetacyclopentadienes play a vital role in the subsequent P-P/P-C bond breaking/forming. It is found that, although the first P-C formation is involved in the assembly of thecyclo-P-3[R4C4P3](-)unit, the construction of the aromatic five-membered P(1)heterocycle [R4C4P](-)is completed prior to thecyclo-P(3)formation. The reaction mechanism has been carefully elucidated by analyses of the geometric structure, frontier molecular orbitals, bond index, and natural charge, which greatly broaden and enrich the general knowledge of the direct functionalization of P-4.