Characterization of a 3,4-Dihydro-1,3,4- triphosphacyclopenta[a]indene as an Isomer of a Mes*-substituted 1,3,6- Triphosphafulvene (Mes* = 2,4,6- t-Bu3C6H2)

Reaction of 2,2-dibromo-1-(2,4,6-tri-t-butylphenyl)-1-phosphaethene and t-butyllithium gave a 3,4-dihydro-1,3,4-triphosphacyclopenta[a]indene as an isomer of a bulky 1,3,6-triphosphafulvene, which was isolated as a major product in this reaction, and the structure was confirmed by X-Ray analysis. Spectroscopicand redox properties of the 3,4-dihydro-1,3,4triphosphacyclopenta[a]indene have been studied.