Department of Chemistry, Fisk University, 1000 17th Avenue North, Nashville, Tennessee 37208
B. Ramachandran
Chemistry, College of Engineering & Science, Louisiana Tech University, Ruston, Louisiana 71272
lpratt@fisk.edu
Received May 3, 2005
Abstract:
Computational methods were used to determine the structure, bonding, and aggregation states of
oxiranyllithium in the gas phase and in THF solution, at 200 and 298 K. THF solvation was modeled
by microsolvation with explicit THF ligands, forming a supermolecule that includes the oxiranyllithium aggregate and its first solvation shell. Because oxiranyllithium has a chiral center, two
diastereomeric dimers were formed, the RR and the RS, along with their enantiomers. Similarly,
three diastereomers of the tetramer were formed, the RRRR, RRRS, and RRSS and their
enantiomers. Oxiranyllithium was found to exist predominantly as the tetramer in the gas phase,
while the dimer was the dominant species in THF solution. The relative concentrations of the
different stereoisomers were calculated from equilibrium constants.
