• cations;
  • chalcogens;
  • main group elements;
  • NMR spectroscopy;
  • phosphorus


Cationic R2P5+ cage compounds (1+) have been synthesized by the stoichiometric reaction of R2PCl, GaCl3 and P4. The reaction conditions depend on the substituent R. Alkyl-substituted derivatives (1 a1 d[GaCl4]) are best synthesized under solvent-free conditions, whereas aryl-substituted derivatives (1 e1 h[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 31P NMR spectroscopy in solution and single-crystal structure determination. Subsequent chalcogenation reactions of cations R2P5+ (1 a+, 1 e+) and trication Ph6P73+ (33+) with elemental sulfur (α-S8) or grey selenium (Segrey) yielded a series of unique polyphosphorus–chalcogen cations (4 a+, 4 e+, 5 a+, 62+ and 72+), possessing nortricyclane-type molecular structures. An in-depth study of the 31P{1H} and 77Se NMR spectroscopic parameters is presented, and correlations between the substitution pattern and the observed structural features have been investigated in detail.