1,4-DIHYDRO-1-LAMBDA(5),4-LAMBDA(5)-[1,4] DIPHOSPHININES AND A DIHYDRO-1-LAMBDA(3),4-LAMBDA(3)-[1,4]DIPHOSPHININE

Reaction of thio- or dithiocarbonic acids with ethinyl amino phosphane s leads to 1,4-dihydro-1 lambda(5),4 lambda(5)-[1,4]diphosphinine-1 ,4 -disulfides. By this route compounds 4, 7, and 8 have been prepared. D esulfurization of 4 with tri-n-butylphosphane results in 1,2,4,5-tetra phenyl-1,4-dihydro-1 lambda(3),4 lambda(3)- [1,4]diphosphinine 5, whic h can be oxidized with tert-butyl-peroxide to the corresponding dioxid e, 6. From the reaction mixture of phenyl-phenylethinyl diethylamino p hosphane and thioacetamide compound 4 and the unsymmetrical 1,4-dihydr o-1 lambda(5),4 lambda(5)[1,4]diphosphinine 9 were isolated. Propertie s, nmr, ir and mass spectra of all new products are reported. A mechan ism for the formation of 9 is suggested. The results of the X-ray stru cture determination of 8 and 9 are described.