Infrared Spectra of Ethylenediamine and the Dimethylethylenediamines

The coordination compound formed between ethylenediamine and cellulose has already been reported (1,2), and a study is in progress concerning the manner in which bonding occurs between the hydroxyl groups of the cellulose and the amino groups of the diamine. Two N-substituted diamines, N,N-dimethylethylenediamine (asymmetrical) and N,N'-dimethylethylenediamine (symmetrical), are on hand for use in an attempt to elucidate the bonding and structure of the cellulose-diamine complex. Infrared absorption spectroscopy was considered an invaluable tool for this structure study, complementing x-ray diffractometry, but its use was quickly hampered by lack of suitable infrared absorption data on the diamines. A search of the literature failed to turn up any spectra for the dimethylethylenediamines, either published or cataloged. Only one paper (3) was found for ethylenediamine, but the published spectrum (liquid film) is only over the range 3500-2700 cm⁻¹ (2.85-3.70 microns). In the present paper the infrared spectra of ethylenediamine and the two dimethylethylenediamines are given over the range 2-13 microns (5000-770 cm⁻¹), and the absorption bands observed are correlated with molecular structure.