Heterometathesis of diphosphanes (RP-PR) with dichalcogenides (R'E-ER', E = O, S, Se, Te).

The reactions of RP-PR with R'E-ER', (where E = Se, S, O, Te) to give RP-ER' have been explored experimentally and computationally. The reaction of PhP-PPh with PhSe-SePh gives PhP-SePh (1) rapidly and quantitatively. The P-P/Se-Se reaction is inhibited by the addition of the radical scavenger TEMPO which is consistent with a radical mechanism for the heterometathesis reaction.

Radical-initiated P,P-metathesis reactions of diphosphanes: evidence from experimental and computational studies.

By combining the diphosphanes Ar2P-PAr2, where Ar = C6H5, 4-C6H4Me, 4-C6H4OMe, 3,5-C6H3(CF3)2, it has been shown that P,P-metathesis generally occurs rapidly under ambient conditions. DFT calculations have shown that the stability of unsymmetrical diphosphanes Z2P-PZ'2 is a function of the difference between the Z and Z' substituents in terms of size and electronegativity. Of the mechanisms that were calculated for the P,P-metathesis, the most likely was considered to be one involving Ar2P˙ radicals.