Reaction of a diphosphane with a chlorophosphane in the presence of SnCl2 or AlCl3 leads to the formation of dicationic heterocycles with three (3P) or four (4P) linked phosphorus atoms. Some 3P derivatives with small alkyl substituents may also be prepared by direct alkylation of cyclic triphosphenium ions. Several new species were prepared in solution, some of which were isolated and characterised by single-crystal X-ray diffraction. Investigations into the factors favouring formation of 3P or 4P species are described.
In a notable extension of previous work, we have shown that several diphosphanes will form larger (7- or 8-membered ring) cyclic triphosphenium ions (CTIs) in solution by reaction with PX3 (X=Cl, Br or I), sometimes in the presence of SnCl2 or SnBr2. We have also formed new CTIs from two ferrocene derivatives. The ions are readily identifiable by 31P NMR solution-state spectroscopy, having large 1JP–P values between the middle ‘bare’ phosphorus atom PA and the outer phosphorus atoms PB (and PC where the outer groups are inequivalent). In addition, some data for known CTIs, but with different counter-ions, are presented. Three of the new CTIs have been successfully protonated, two by both AlCl3/tBuCl and triflic acid, and one via the triflic acid route only.
Alice J. Boyall合作论文数2Keith B. Dillon合作论文数2jennifer c potts合作论文数1Coffer Philippa K合作论文数1Alan M. Kenwright合作论文数Department of Chemistry, University of Durham1
Judith Howard合作论文数Department of Chemistry, Durham University1
Michael Probert合作论文数1
Helena J. Shepherd合作论文数Université de Toulouse, Université de Toulouse1Philippa K. Monks合作论文数1Andres E. Goeta合作论文数Department of Chemistry, University of Durham1
Amber Thompson合作论文数Department of Chemistry, University of Oxford/Department of Paediatrics, University of Oxford1
