A Study of the Infrared Spectrum of the Amide Group

Abstract

The very strong 1560-cm−1 band of the N-substituted amide group has been assigned previously either to ν(C–N) or to δ(N–H). This investigation consisted of a study of the frequency shifts of this and other bands in the infrared spectra of several N-butyl- and N,N-dibutyl-ethanamides upon substitution of chlorine and fluorine in the 2 position. On the basis of these shifts and other properties of the band in question, observed in the spectra both of the pure compounds and of their CCl4 solutions, it is concluded that the ν(C–N) assignment is correct. The apparent absence of the corresponding band from the spectrum of the N,N-disubstituted amide group is explained by the accidental degeneracy of ν(C=O) and ν(C–N). Other bands were cataloged and assigned where possible.

Infrared and Raman Spectra of Series of Deuterated Alcohols

“…The parallel bending deformation frequency of the NH group has been assigned recently to the region from 1406 to 1460 cm.-1 (11). The vibrational assignment of the OH deformation frequency of alcohols, in which the hydrogen moves perpendicular to the OH bond and out of the C-OH plane, recently was assigned by Stuart and Sutherland (19) to a broad band in the liquid starting at 800 cm.-1, reaching a maximum near 670 cm.-1 and extending beyond 500 cm.-1 In deuterated methanol this was found to shift to 475 cm.-1 Koehler and Dennison (9) assign a broad band with a maximum at about 270 cm.-1 for this vibration in methanol vapor.…”

The SPECTRA OF SATURATED AND Α–β UNSATURATED SIX-MEMBERED LACTAMS

“…The 3400-3500 cm.-I bands in the spectra of liquid films of N-dialkyl amides have been noted by Letaw and Gropp (10). They consider them to be overtones of the 1600-1700 cm.-I bands.…”

Infrared Spectroscopy

“…The specific molecules studied from a more theoretical aspect include: acetylene and substituted acetylenes (64,65,401,628), aliene (143, 366, 408, 451), the amide group (348), arsine (435), benzene and substituted benzenes (180-186, 216, 560), boron fluorides (114), bromoacetvl chloride (421), bromine pentadfluoride (86), carbon dioxide (144, 450, 630), carbon monoxide (404), chloroacetone (410), ethylene chlorohydrin (411), chlorine dioxide (152, 453), cyanic and thiocyanic acid (593), cyanuric acid (431), cyclobutanes (330), cyclohexanes (334), cyclopentane (615), decaborane (310), diborine (352), deuterium oxides (37,38), diacetylene (187,188,190,191,289), dioxane (385), ethane and substituted ethanes (45, 251,327, 386, 388, 438, 440-442, 453, 469, 559, 561, 598, 610), ethyl alcohol (23), ethylenes and halogenated ethylenes (79,119,437,440), ethylene oxide (235), ferrocene (357), fluorine cyanide (590), fluoroform (165), formaldehydes (193,432), furan (236), germanium tetrafluoride (95), germanium tetramethyl (358), hydrogen bromide (595), HD molecule (651), hydrogen cyanide (75,149,283,305), hydrogen iodide (63), hydrogen sulfide…”

“…109, 163,273,287,[295][296][297][298]300, SOI,616-519, 523, 585, 604, 619). Other papers related to proteins, synthetic proteins, and the peptide link (l,55, 170, 171,200,202,203,206,282, SIS,348,409,412,413).…”