Hydrogen Bonding of Hydrazoic Acid in Solid Nitrogen

Abstract

The infrared spectrum of hydrogen bonded HN₃ dimers in solid nitrogen has been determined. A dimer band at 387 cm⁻¹, assigned to the torsional distortion of the hydrogen bond, indicates the dimer has an open, not a cyclic structure. The hydrogen bond bending force constant is 0.09 mdyn/Å. The hydrogen bond frequency shift in the N–H stretching mode is 150 cm⁻¹, which, by comparison to similar systems, suggests a hydrogen bond energy of about 2 kcal/mole. The infrared spectrum of monomeric HN₃ casts doubt upon the earlier gas‐phase assignment of ν₆. According to the matrix spectrum, the band center is more likely to be near 588 cm⁻¹.