1,2λ5,5λ5-azadiphospholium structures

The reactions of bromophenylacetylene with the diphenylphosphino amines (Ph₂P)₂NH and (Ph₂P)₃N result in the 1,1,3,3,4-pentaphenyl-1,2,5-azadiphospholium bromide ( 5 ) and its 4-diphenylphosphino derivative ( 7 ). Their X-ray structure analyses show planar rings for the cations. The small endocyclic angle at the nitrogen ring member is associated with PN bonds that are longer than in the acyclic cation (Ph₃P)₂N⁺. The data fit to a negative linear relationship of PN bond lengths and PNP bond angles. © 1997 John Wiley & Sons, Inc.     

1λ5,3λ5-Diphospholium ions

One example each is given for the reaction of bromoacetylenes and ethynyl-phenyliodonium tosylates with bis(diphenyl phosphino)methane. The yellow crystalline 1:1-addition products are diphospholium salts. They readily and selectively hydrolyze to give 2-phosphinoylethenyl phosphonium salts.     

1, 2λ5-azaphosphinines and a new 1λ5, 3λ5-. Diphosphinine

The 1,2-azaphosphinine, 9 , and the 1,3-diphosphinine, 10 , can be isolated from a mixture resulting from the reaction of 1,1,3,3-tetrakis(dimethylamino)-1λ⁵,3λ⁵-diphosphete, 1 , and ethyl isothiocyanate. The reaction of 1 with phenyl isothiocyanate yields the 1,2-azaphosphinine, 16 . Mechanisms for the formation of the compounds 9 , 10 , and 16 are suggested. The properties, the NMR, mass, and IR spectra, and the molecular and crystal structures of 9 and 10 are described and discussed.