AB-INITIO STUDIES ON GEOMETRIES AND ELECT RONIC-PROPERTIES OF THE NEREISTOXIN AND EVISECT

Ab initio calculations have been carried out at the Hartree-Fock/6-31G level to determine the geometries of the nereistoxin (C5H11NS2) and evisect (C5H11NS3). Two Stable conformations of chair and boat forms o f the evisect have been found in the global optimizations, At the seco nd Moller-Plesset perturbation theory, MP2/6-31G level, the chair for m is 27.06 kJ/mol which is more stable than the boat form, The molecul ar electrostatic potentials obtained from MP2/6-31G wave-functions, T he relationship between biological activity and electrostatic potentia ls have been discussed, The atomic charges from Mulliken population an alysis is faulty in the nereistoxin and evisect, Brenneman's CHELPG me thod was used in the calculations.