Supramolecular chemistry of chiral rhenium Lewis acids of the formula [(eta(5)-C5R5)Re(NO)(CO)(PPh3)](+): Synthesis and crystal structure of a 2 : 1 adduct of an ammonia complex and 18-crown-6

When ether is added by vapor diffusion to a CH3CN solution of racemic [(5-C5H5)Re(NO)(PPh3)-(NH 3)]+PF6- (1+PF6-) and 18-crown-6 (1:2 mol ratio), a 2:1 adduct of composition {(1+)(18-crown-6)(1+)}-2PF6-OEt2 crystallizes (94%). A crystal structure shows opposite enantiomers of the cations about a crown-based inversion center, each with three NHO hydrogen bonds to complementary sets of ether oxygens - a meso assembly. NMR data also establish binding in solution.

Supramolecular chemistry of chiral rhenium Lewis acids of the formula [(eta(5)-C5R5)Re(NO)(CO)(PPh3)](+): Synthesis and crystal structure of a 2 : 1 adduct of an ammonia complex and 18-crown-6 Academic Article