Methylphosphinidene (CH3P) and its rearrangement to phosphaethylene (CH2PH): toward the observation of ground-state triplet CH3P

Abstract

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Methylbismuth: an organometallic bismuthinidene biradical

“…This shows, that the ground state (electronic) structure of species with the sum formula ECH 3 are fundamentally different, depending on the choice of the element E. For E ¼ Bi the triplet bismuthinidene 3 is energetically favored and observed (vide supra), whereas for the lighter congeners (E ¼ N, P), the formation of the methylene species HN]CH 2 and HP] CH 2 has been determined to be more favorable. [27][28][29][30][31][32]53 Upon photoionization of 3, one electron is removed from either of the two degenerate SOMOs, which correspond in rst approximation to the p x and p y orbital on the Bi center. The computations for the ionic ground state, [BiCH 3 ] + (3 + ), yielded a shortening of the Bi-C bond (from 2.27 A in 3 to 2.21 A in 3 + ) and a deformation of the methyl group with a tilt angle of 4 relative to the Bi-C axis.…”

Methoxyphosphinidene and Isomeric Methylphosphinidene Oxide

“…Intensive computational studies on MeP ( 2 ) suggest a triplet ground state, resembling the well-established analogous nitrene MeN . Despite the large barriers (>20 kcal mol –1 ) for the rearrangement to phosphaethene CH 2 PH, , MeP remains as yet unobserved.…”

“…As a class of low-valent organophosphorus compounds (OPCs), phosphinidenes keep attracting enormous interest, not only due to broad applications as in situ phosphorus reagents in synthetic chemistry but also because they form isolable complexes with diverse carbenes and transition metals in which the terminal phosphorus atom can be either nucleophilic or electrophilic . In contrast to the intensively explored in situ trapping and coordination chemistry of phosphinidenes, the attempts to obtain fundamental knowledge about the highly reactive “naked” phosphinidenes (Scheme ) such as the parent molecules HP ( 1 ), MeP ( 2 ), PhP ( 3 ), and CH 2 CHP ( 4 ) are largely hampered by the facile inter- or intramolecular reactions under the formation conditions.…”

On the π-bond strengths in higher element homologues of methylenephosphane and diphosphene

“…Meanwhile the e †orts are documented in various reviews and book contributions, with regard to experimental1h11 as well as theoretical studies.12h19 Detailed calculations on methylenephosphane and its rearrangement to methylenephosphinidene were performed. 19 The n-bond strengths in the second and third period of elements were Ðrst explored by Schmidt et al 16 These authors investigated the rotational barriers and the energy lowest triplet states for X, Y \ C, Si and H 2 XxYH 2 , for X, Y \ N, P by MCSCF calculations. A four-H 2 XxXY, electron, four-orbital fully optimized reaction space20 was used.…”