Synthesis of Cationic R2P5+ Cages and Subsequent Chalcogenation Reactions

Cationic R2P5+ cage compounds (1(+)) have been synthesized by the stoichiometric reaction of R2PCl, GaCl3 and P-4. The reaction conditions depend on the substituent R. Alkyl-substituted derivatives (1a-1d[GaCl4]) are best synthesized under solvent-free conditions, whereas aryl-substituted derivatives (1e-1h[GaCl4]) are formed in C6H5F. All compounds have been prepared on a multi-gram scale in good to excellent yields and have been fully characterized with an emphasis on (PNMR)-P-31 spectroscopy in solution and single-crystal structure determination. Subsequent chalcogenation reactions of cations R2P5+ (1a(+), 1e(+)) and trication Ph6P73+ (3(3+)) with elemental sulfur (-S-8) or grey selenium (Se-grey) yielded a series of unique polyphosphorus-chalcogen cations (4a(+), 4e(+), 5a(+), 6(2+) and 7(2+)), possessing nortricyclane-type molecular structures. An in-depth study of the P-31{H-1} and (SeNMR)-Se-77 spectroscopic parameters is presented, and correlations between the substitution pattern and the observed structural features have been investigated in detail.