A b i n i t i o SCF MO calculations of the potential surfaces of thiocarbonyls. III. Ground state and first excited triplet state of thiourea, (NH2)2CS

Abstract

Equilibrium geometries for the ground and first excited triplet states of thiourea have been calculated using ab initio SCF MO methods. Apart from the pyramidality of the NH2 groups, the calculations for thiourea indicate a planar ground state analogous to simple tetraatomic thiocarbonyls. The first triplet state out-of-plane bending mode frequencies have been calculated by a perturbational method. The rotation of the NH2 moiety about the C–N bond has been studied for the ground and first excited triplet states and the barriers to these internal rotations have been calculated.