A Masked Phosphinidene Trapped in a Fluxional NCN Pincer

Abstract

The trapping of a phosphinidene (R-P) in an NCN pincer is presented. Stabilized phosphinidene 1 was characterized by P{ H}, H, and C{ H} NMR spectroscopy, exhibiting an averaged C 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 above the ground state.

Diiminepyridine‐Supported Phosphorus(I) and Phosphorus(III) Complexes: Synthesis, Characterization, and Electrochemistry

“…The imine C=N distances are significantly longer [C1–N1 1.318(3) Å, C11–N3 1.309(3) Å] compared to the structure of a related proligand Ar DIP t Bu [Ar = 2,6‐dimethylphenyl; average d (C=N) = 1.27 Å], consistent with iminium and pyridinium charge delocalization character upon coordination to phosphorus. Hemilability of donor arms in phosphorus coordination complexes has been exploited to access masked Lewis acidic character for P (III) dications, and diimine‐ligated phosphinidenes . The P (I) centre has pseudo ‐T‐shaped geometry, with a tied‐back N1–P1–N3 angle of 162.75(8)° (DFT: 162.4°) and two lone pairs.…”

From a 2,1‐Benzazaarsole to Elusive 1‐Arsanaphthalenes in One Step

“…Quite unexpectedly, the 1‐arsanaphthalenes (Figure D) were obtained as final products, thereby providing the first straightforward method for their synthesis. As our group and others have recently showed that 2,1‐benzazaphospholes are structurally related to 1 and also that the heavier analogues are synthetically accessible, this procedure has great potential due to its possible application within the whole of Group 15.…”

Hetero Diels–Alder Reactions of Masked Dienes Containing Heavy Group 15 Elements

“…These isomers are only 0.7 (for 2 a ) and 0.2 kcal mol −1 (for 3 a ) higher in energy than their respective C 2 v symmetric ground states. However, the bond length differences between the two intramolecular N→E bonds are much less pronounced (0.2 and 0.1 Å for 2 a and 3 a , respectively) than the experimental values found for the related phosphinidenes (0.9 Å) and arsenidenes (0.5–0.7 Å) …”

“…Recently, ourselves and others have isolated N , C , N ‐chelated analogues of I , inducing the organopnictogen(I) compounds ArE ( 1 – 3 ) (Ar=2,6‐(RN=CH) 2 C 6 H 3 , E/R=As/Dmp ( 1 ), Sb/ t Bu ( 2 ), and Bi/ t Bu ( 3 ), where Dmp=2,6‐Me 2 C 6 H 3 ), and their structures have been characterized in detail by a combination of experimental and DFT studies …”