Abstract

<i>N</i>-Methyl compounds exhibit a weak to medium absorption band in the 2820–2760 cm⁻¹ region, which is characteristic for the <i>N</i>-methyl group. This diagnostic test is shown to be applicable to potassium bromide spectra and to the wide variety of molecules having an <i>N</i>-methyl substituent examined. Aldehydes, amino acid hydrochlorides, secondary and tertiary alkylamines, methoxy compounds, and nitrogen heterocyclic molecules exhibit absorption which may overlap this region and the detection of an <i>N</i>-methyl substituent for these classes of compound may be less definite. This diagnostic band is absent in potassium bromide spectra of the amine salts in which the nitrogen lone pair of electrons is involved in bond formation.

Infrared Band Assignments for the 2900 cm⁻¹ Region Methyl Group Vibrations in XC₆H₄COOCH₃, XC₆H₄CH₃, and XC₆H₄COCH₃ Molecules

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Generation of mid- to far-infrared ultrashort pulses in 4-dimethylamino-N-methyl-4-stilbazolium tosylate crystal

Takuya Satoh, Yoshihiro Toya, Shunsuke Yamamoto, Tsutomu Shimura, Kazuo Kuroda, Yoshinori Takahashi, Masashi Yoshimura, Yusuke Mori, Takatomo Sasaki, and Satoshi Ashihara
J. Opt. Soc. Am. B 27(12) 2507-2511 (2010)

Repulsive Potential between Nonbonded Methyl Groups

John Overend and James R. Scherer
J. Opt. Soc. Am. 50(12) 1203-1207 (1960)

Sub-parts-per-billion level detection of dimethyl methyl phosphonate (DMMP) by quantum cascade laser photoacoustic spectroscopy

Anadi Mukherjee, Ilya Dunayevskiy, Manu Prasanna, Rowel Go, Alexei Tsekoun, Xiaojun Wang, Jenyu Fan, and C. Kumar N. Patel
Appl. Opt. 47(10) 1543-1548 (2008)

Structural, optical, and electrical properties of the organic molecular crystal 4-N,N- dimethylamino-4′-N′-methyl stilbazolium tosylate

S. Follonier, M. Fierz, I. Biaggio, U. Meier, Ch. Bosshard, and P. Günter
J. Opt. Soc. Am. B 19(9) 1990-1998 (2002)