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 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. We reported here a theoretical insight into 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. 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 cyclo -P 3 [R 4 C 4 P 3 ] - unit, the construction of the aromatic five-membered P 1 -heterocycle [R 4 C 4 P] - is completed prior to the cyclo -P 3 formation. The reaction mechanism has been carefully elucidated by the analyses of geometric structure, frontier molecular orbital, bond index, and natural charge, which greatly broaden and enrich general knowledge on the direct functionalization of P 4 .