• Nieger, Martin
• Cicač-Hudi, Mario
• Gudat, Dietrich
• Feil, Christoph M.
• Birchall, Nicholas

Abstract

<p>Reaction of the iodide salt of a secondary imidazolio-iodophosphine [(L)PHI]I (L+ = 1,3-diarylimidazolium-yl) with an imidazolio-phosphide (L)PH in the presence of GaI3 afforded the isolable salt of a dicationic, bis(imidazolio)-substituted dihydro-diphosphine [(L)(2)P2H2][GaI4](2). Non-preparative formation of the cationic diphosphines was also observed upon spontaneous "dehalo-coupling" of [(L)PHI](+), or in reactions of [(L)PHI]I and (L)PH in the absence of GaI3. Further reaction of [(L)(2)P2H2](2+) with (L)PH produced an iodide salt of a known (bis)imidazolio-diphosphide monocation [(L)(2)P2H](+). The identity of cationic diphosphines and diphosphides was established by single-crystal X-ray diffraction studies. NMR spectroscopy revealed that dications [(L)(2)P2H2](2+) exist as a mixture of meso- and rac-diastereomers in solution. Computational studies confirmed the stereochemical assignment of the isomers observed, and gave insight into the bonding situation of the diphosphine dications.</p>

Topics

• x-ray diffraction
• Nuclear Magnetic Resonance spectroscopy