STUDIES OF HYDROGEN PEROXIDE: THE INFRARED SPECTRUM AND THE INTERNAL ROTATION PROBLEM

Several H2O2 infrared absorption bands have been obtained under 1/0.2 cm. resolution. They demonstrate both doubling due to internal rotation and effects due to the ine tial asymmetry. The ground state rotational constants are found to be: A equals 1/10.068 cm, B equals 0.8740, C equals 0.8384. These parameters indicate a wide dihedral angle for H2O2, as proposed in the following structure: OO bond equals 1.475 A, OH bond equals 0.950 A, dihedral angle equals 119.8 degrees and OOH angle equals 94.8 degrees. The constants are applied to the microwave data for H2O2 and the deuterated species. The ground state splitting is found to be 1/11.44 cm, and this, used with the recently reported torsion at 1/317 cm, yields the barriers hindering internal rotation. They are V sub cis equals 1/1300 cm and V sub trans equals 1/300 cm. A simple correlation of the IR doublings is attempted. (Author)