SYNTHESIS AND MOLECULAR STRUCTURE OF Mes(H)P-P(H)Mes (Mes = 2,4,6-Me3C6H2)

Cp˚2Zr(PMesPMes) (Cp˚ = η5-C5Me4Et. Mes = 2,4,6-Me3C6H2) reacts with phenylacetylene with cleavage of the Zr-P bonds and formation of Mes(H)P-P(H)Mes (1). 1 is also obtained from LiPHMes and 1,2-dibromoethane. The 31P NMR spectrum of 1 shows the presence of both isomers (d,l and meso form). A crystal structure determination carried out on meso-Mes(H)P-P(H)Mes showed that in the solid state the bulky Mes groups have a trans arrangement.