Crystal and Molecular Structure of Hydrogen Peroxide: A Neutron-Diffraction Study

The coordinates and thermal parameters of the O and H atoms in solid H2O2 have been determined by a single-crystal neutron-diffraction study. Final values were obtained by least-squares refinement based on 91 observed intensities of the hk0, hhl, and h0l reflections. The molecular parameters (uncorrected for the effect of thermal motion) are as follows: O–O distance, 1.453±0.007 Å; O–H distance, 0.988±0.005 Å; O–O–H angle, 102.7±0.3°; dihedral angle between the two O–O–H planes, 90.2±0.6°. Hydrogen bonding occurs with an O–H···O distance of 2.799±0.008 Å. The O–H bond distance corrected for thermal motion is 1.008±0.005 Å. Comparison of these results with those reported by others from studies of H2O2 vapor and of various crystals containing H2O2 indicates that the dihedral angle is quite sensitive to the environment of the molecule.