Seleniranium and Telluriranium Salts

Seleniranium salts [Ad(2)SeR](+) X- (2-8), which are moderately stable at room temperature, were synthesized by addition of RSe+X- equivalents to the bulky olefin bis(adamantylidene) Ad=Ad (1), where R is aryl or alkyl and X- is Tf2N-, B(C6F5)(4)(-), or SbCl6-. Unstable telluriranium salts [Ad(2)TeR]X-+(-) (9-12) were obtained by addition of RTe+X- equivalents to 1 (R=Ph, Et; X-=Tf2N-, BF4-). The compounds were characterized by NMR spectroscopy and quantum chemical calculations, and the Se compounds also by ESI mass spectrometry. Crystal structures were determined for seleniranium salts 2 and 7 and telluriranium salt 9.