Knowledge Bank

The microwave spectrum of l-methyl cyclopropene has been studied in the region 8-36 GHz. Both a-type and b-type transitions have been observed. The $CH3-C=C$ angle was found to be $152\circ 481$ and the barrier to internal rotation of the methyl group has been found to be $1390\pm 50$ cal/mole. Some transitions and splittings in the first excited torsional state have been observed.