ISOMERIZATION OF 2-PHOSPHA-4-SILA-BICYCLO[1.1.0]BUTANE

In analogy with the valence isomerism of the hydrocarbons bicyclobutane, 1,3-butadiene and cyclobutene, the rearrangements for 2-phospha-4-sila-bicyclo[1.1.0]butane were studied at the B3LYP/6-311+G** G**basis set was employed throughout for the geometry optimizations. First and second order energy derivatives were computed to confirm the nature of the minima and transition structures. Intrinsic reaction coordinate calculations (IRC) were performed to establish connections between transition structures and minima. level of theory. The monocyclic 1,2-dihydro-1,2-phosphasilete is shown to be the thermodynamically preferred product, in contrast to the isomerism of the hydrocarbons that favors the 1,3-butadiene structure.