Notizen: Beiträge zur Chemie des Phosphors, 771 Spektroskopischer Nachweis eines Diphosphirans (Diphosphacyclopropans) / Contributions to the Chemistry of Phosphorus, 771 Spectroscopic Detection of a Diphosphirane (Diphosphacyclopropane)

Abstract

1,2 - Diphenyl - 3,3 - dimethyl - diphosphirane (1,2- Diphenyl- 3,3- dimethyl-diphosphacyclopropane) (1) is formed by the reaction of K(C6H5)P–P(C6H5)K with 2,2-dichloropropane in n-pentane at —30 °C. It could be detected and identified by its 31P NMR singlet at —122 ppm, which lies in the high field region characteristic for phosphorus three-membered ring compounds, as well as by its mass spectrum. Besides, (PC6H5)5 and several cyclocarbaphosphanes of ring sizes five and six are formed. After the reaction of (CH3)3Si(C6H5)P–P(C6H5)Si(CH3)3 with methylene iodide a weak 31P NMR signal at —147 ppm could be observed, which probably corresponds to the 1,2-diphenyl-diphosphirane.