Amines infrared frequencies

Section 22 19 The N—H stretching frequency of primary and secondary amines appears m the infrared m the 3000-3500 cm region In the NMR spectra of amines protons and carbons of the type H—C—N are more shielded than H—C—O... 

Infrared radiation, electromagnetic spectrum and, 419, 422 energy of. 422 frequencies of, 422 wavelengths of, 422 Infrared spectroscopy, 422-431 acid anhydrides, 822-823 acid chlorides, 822-823 alcohols. 428, 632-633 aldehydes, 428. 730-731 alkanes, 426-427 alkenes, 427 alkynes, 427 amides. 822-823 amines, 428, 952 ammonium salts, 952-953 aromatic compound, 427-428, 534 bond stretching in, 422... 

Poly(acrylic acid) (PAA), a MIP film candidate, has been shown to bind to the bare CdSe surface from methanol solution with considerable affinity [13]. Placement of drops of a PAA-methanol solution on the surface of CdSe and evaporation of the solvent leaves a PAA film on the semiconductor surface. Once coated with this PAA film, CdSe shows no change in PL intensity in the presence of amines. Despite the lack of a PL change, the deprotonation of the carboxylic acid could be observed by the shifting of the infrared (IR) carboxylic acid peak to lower frequencies characteristic of the carboxylate anion upon amine binding, as shown in Fig. 5. The reaction chemistry is ... 

The IEs on amine basicity are also due to changes in vibrational frequencies, not only computationally but also experimentally. Gas-phase IEs of O.lOkcalmol-1 per CD3 group on basicities of methylamine, dimethy-lamine, and trimethylamine can be reproduced by ab initio force constants for C-H stretching, which increase on TV-protonation.100 Infrared spectra of amines show characteristic bands (called Bohlmann bands ) in the 2700-2800 cm-1 region, lower than the 2900 cm-1 of a typical C-H stretch.169,170 Upon /V-protonation these bands revert to a typical, higher frequency. Therefore the zero-point energy of the C-H increases on... 

The Infrared Region 515 12-4 Molecular Vibrations 516 12-5 IR-Active and IR-lnactive Vibrations 518 12-6 Measurement of the IR Spectrum 519 12-7 Infrared Spectroscopy of Hydrocarbons 522 12-8 Characteristic Absorptions of Alcohols and Amines 527 12-9 Characteristic Absorptions of Carbonyl Compounds 528 12-10 Characteristic Absorptions of C—N Bonds 533 12-11 Simplified Summary of IR Stretching Frequencies 535 12-12 Reading and Interpreting IR Spectra (Solved Problems) 537 12-13 Introduction to Mass Spectrometry 541 12-14 Determination of the Molecular Formula by Mass Spectrometry 545... 

Further insight into histidine encapsulation of nanoclusters (Au, Ag, Cu, Pt) was provided by infrared spectroscopy. IR spectra of free histidine showed a set of stretching bands for the N-H bond of the amine and strong peaks (1630 cm, 1413 cm ) attributed to an asymmetrical and symmetrical C02 stretch. As a result of nanocluster stabilization and the subsequent formation of a metal-N(His) interface, the N-H stretching frequencies broadened and the number of bands decreased relative to free histidine due to the interactions with the dielectric field at the nanocluster surface. ... 

A number of other infrared works (22) have led to the conclusions that (1) the C=N stretching frequency is higher in the S-bonded than in the N-bonded isomer, and (2) the C-S stretching frequency is higher in the N-bonded than in the S-bonded isomer. In fact, the N-bonded isomer mentioned above exhibits the C=N and C-S stretching bands at 2089 and 854 cm., respectively, whereas the S-bonded isomer exhibits them at 2119 and 720-690 cm., respectively. Recently, Raymond and Basolo (25) prepared a complex, [Cu(tren)(NCS)(SCN)] (tren = triaminotriethyl-amine, N(CH2CH2NH2)3), in which M-NCS and M-SCN bonds are mixed in one complex. Its structure may be depicted as... 

According to Pestemer and Lauerer 40), the existence of addition complexes between isocyanates and tertiary amines as postulated by Baker and co-workers is shown by the appearance of infrared bands at expected frequencies. The assumed structure of the complex... 

In fact, the first effect of intramolecular hydrogen bonds in the condensed phase is the self-association of amines (as well as alcohols), affecting their physical and spectroscopic properties, in particular the N—H frequencies in the infrared spectra. 

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