A Masked Phosphinidene Trapped in a Fluxional NCN Pincer.

Authors :: Hyvl J
Yoshida WY
Rheingold AL
Hughes RP
Cain MF
Source :: Chemistry (Weinheim an der Bergstrasse, Germany) [Chemistry] 2016 Dec 05; Vol. 22 (49), pp. 17562-17565. Date of Electronic Publication: 2016 Oct 24.
Publication Year :: 2016
Abstract: The trapping of a phosphinidene (R-P) in an NCN pincer is presented. Stabilized phosphinidene 1 was characterized by <superscript>31</superscript> P{ <superscript>1</superscript> H}, <superscript>1</superscript> H, and <superscript>13</superscript> C{ <superscript>1</superscript> H} NMR spectroscopy, exhibiting an averaged C <subscript>2v</subscript> symmetry in solution between -60 and 60 °C. In the solid state, the phosphinidene is coordinated by one adjacent N atom featuring a formal P-N bond (1.757(2) Å) to give a five-membered ring with some aromatic character, confirmed by DFT calculations (B3LYP-D3/6-311G**++) to be the ground-state structure. Equilibration of the two N ligands occurs rapidly in solution via a "bell-clapper"-type process through an associative symmetric transition state calculated to lie 4.0 kcal mol <superscript>-1</superscript> above the ground state.<br /> (© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)