The Infra-Red Absorption Spectrum of Methylamine Vapor

Abstract

The infra-red absorption of methylamine vapor has been measured from 2 to 18μ with a cell of 18 cm length using pressures from 2 to 55 cm. A total of nineteen bands has been observed, nine of which are assigned to fundamental vibrations. The bending vibrations of the two groups give rise to several bands in the region from 6 to 8μ. This causes considerable overlapping which makes it difficult to locate band centers and to determine band types in this region. Three bands which originate from the C – H vibrations occur at wave-lengths between 3.0 and 3.6μ. A band due to the N – H parallel valence vibration has been found at 2.98μ. The most intense band in the spectrum occurs at 12.9μ, and arises from a bending vibration of the hydrogen atoms in the amino group. The parallel vibration between the methyl and amino groups gives rise to an intense band at 9.56μ. This is a parallel band having a sharp and intense zero branch. A band also due to a bending vibration in the amino group was observed at 16μ, and from the experimental curve it can not be said whether it is parallel or perpendicular; hence definite assignment is not made. The other bands which have been observed have been assigned to overtones and combinations.

Structural characterization of ambazone salt with niflumic acid

“…4). This absorption located at ∼1686 cm −1 , can be assigned also to deformation vibration of the protonated secondary amino group [7]. The benzene ring stretching vibration at 1614 cm −1 is not shifted and appeared as a shoulder on the spectrum of the AMB · NIA.…”

“…4), being shifted to ∼1601 cm −1 by salt formation [13]. Cleaves and Plyler [7] correlated the spectral bands at 1625-1516 cm −1 with NH deformation vibration. The pure ambazone spectrum contains the secondary amine vibration at 1508 cm −1 which is shifted in AMB · NIA spectrum to 1516 cm −1 and greatly reduced its intensity.…”

Interfacial crosslinked controlled thickness graphene oxide thin-films through dip-assisted layer-by-layer assembly means

“…Three bands between 3400-3000 cm -1 indicate the presence of primary amines [45][46][47]. Additionally, the spectral bands at 1630 cm -1 and 1516 cm -1 have been correlated with -N-H deforming vibrations [52,53]. Finally, the band at 1250 cm -1 identifies the occurrence of -C-N bonds in aromatic amines [49,54] and the -N-H wagging vibrations are distinguished by the sharp peak at 832 cm -1 [51].…”

Preparation and characterization of ambazone salt with nicotinic acid

“…The salt formation has been shown to modify the NH stretching absorption in amines [16,18]; it was observed that the free bases have a sharp strong band at ~3226 cm -1 due to the NH stretching and that this band is greatly reduced in intensity in the spectra of the AMB•NA. The band at 3146 cm -1 corresponds to the NH vibration [16] for pure AMB.…”

“…4), being located at ~1618 cm -1 by salt formation [17]. Cleaves and Phyler [18] correlated the spectral bands at 1625-1516 cm -1 with NH deformation vibration. Pure ambazone spectrum contains the secondary amine vibration at 1508 cm -1 which is not shifted in AMB•NA spectrum.…”