The First Nonclassical Distonic Ion (original) (raw)

The gaseous and ionized prototype carbonyl ylide, the distonic ion + CH 2-O-CH 2 • , is found to transfer ionized methylene to 1-adamantylphosphaacetylene (1-Ad-CtP), a kinetically stabilized phosphaalkyne, thus forming the 1-adamantylphosphaacetylenium P-methylide ion, 1-Ad-C + dP-CH 2 • , a novel phosphorus, and the first nonclassical distonic ion. The ion abstracts CH 3 S • from CH 3 SSCH 3 and both Br • and C 3 H 5 • from allyl bromide, and this characteristic reactivity demonstrates its distonic character. MO calculations at the Becke3LYP/6-311G(d,p) and MCSCF [CAS(3,3)] levels confirm that 1-Ad-C + dP-CH 2 • bears spatially separated charge and odd spin sites. They also reveal for the ion a phosphaallylic radical structure that stabilizes the radical site, and a σ-bridged structure with three-center two-electron bonds that stabilizes the charge site. This unique electronic structure characterizes 1-Ad-C + dP-CH 2 • as the first nonclassical distonic ion.