STRUCTURES OF ALKALI-METAL PSEUDOHALIDES - LIOCP, NAOCP, LISCP, NASCP

The equilibrium geometries of LiOCP, NaOCP, LiSCP, and NaSCP were calc ulated at the MP2 and QCISD/6311G levels of theory. It was found that all four have pi-type cyclic conformers. In case of the former two, t his form is the most stable isomer, whereas in LiSCP and NaSCP, no oth er conformations but the cyclic exist. Vibrational frequencies and ion ization energies were calculated to facilitate vapor phase identificat ion. Semiempirical quantum chemical and molecular mechanics simulation s were also undertaken to study their behavior in solutions; they are expected to dissociate, and the resulting pseudohalide anions are line ar. Thus the existence of the pi-complex cannot be demonstrated in sol ution.