Hydrogen Bonding in the Amine Hydrohalides: Iii. Near-Infrared Spectra of Aliphatic Amine Hydrohalides

The first overtones of the [Formula: see text] stretching fundamentals are very weak and difficult to locate. Binary combinations between [Formula: see text] stretching and [Formula: see text] bending vibrations and also [Formula: see text] stretching–bending combinations fall into the 4600–4400 cm −1 area for primary and secondary amine hydrohalides and are much stronger. The intensity of these combination bands is not due to the anharnionicity of the potential surface but to the electrical anharmonicity of bending vibrations.