Protonation of ReH3P4 (P = PMe2Ph) with HBF4·OEt2 in Et2O gives ReH4P4+, which neither exchanges with D2 nor reacts with PhC≡CPh, CO, MeCN, or C2H4 under mild conditions. These results, together with an X-ray crystal structure determination, are consistent with a "classical" tetrahydride formulation for this cation, and the lack of reactivity correlates with the absence of coordinated H2 as a ligand. NEt3 will not deprotonate ReH4P4+ since it is a weaker base than ReH3P4. The implied electron-rich character of ReH3P4 thus rationalizes why protonation results in formal oxidation to Re(V), rather than retention of Re(III) as in Re(H)2(H2)P4+. The T1 value of the hydrogens bound to rhenium is 97 ms at -70°C and 360 MHz.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry