A microwave spectroscopic and quantum chemical study of propa-1,2-dienyl selenocyanate (H2
C
CHSeC
N) and cyclopropyl selenocyanate (C3H5SeC
N)†
Abstract
The C
CHSeC
N, and
N, are reported. The
C
CHSeC
N. This conformer is characterized by a C–C–Se–C dihedral angle of 129(5)° from synperiplanar (0°) and is shown to be the global minimum of H2C
C
CHSeC
N. The
N were assigned. This conformer has a H–C–Se–C dihedral angle of 80(4)° from synperiplanar and is at least 3 kJ mol−1 more stable than any other form of the molecule. The microwave study has been augmented by quantum chemical calculations at the B3LYP/6-311++G(3df,3pd) and MP2/6-311++G(3df,3pd) levels of theory.