Carbon-hydrogen stretch

A typical IR spectrum such as that of hexane m Eigure 13 31 appears as a series of absorption peaks of varying shape and intensity Almost all organic compounds exhibit a peak or group of peaks near 3000 cm due to carbon-hydrogen stretching The peaks at 1460 1380 and 725 cm are due to various bending vibrations... 

Carbon-hydrogen stretching vibrations with frequencies above 3000 cm are also found m arenes such as tert butylbenzene as shown m Figure 13 33 This spectrum also contains two intense bands at 760 and 700 cm which are characteristic of monosub stituted benzene rings Other substitution patterns some of which are listed m Table 13 4 give different combinations of peaks... 

Infrared spectra. An FT infrared spectrum of HTE liquid polymer (fan -500) is shown in Figure 2. All spectra of HTE polymers show characteristic absorptions a broad band at 3530 cm-1- for the hydroxyl stretching, three bands at 2958, 2913, and 2875 cm-1 assigned to the carbon-hydrogen stretching, an extremely strong... 

In this particular case, we extracted quantitative data directly from the spectra shown in Fig. 6 at the chosen analytical frequency of 3060 cm 1, the peak of the vinyl carbon-hydrogen stretch absorption. We measured the distance of each curve (in mm) from the log (1/R) value of the 0% vinyl silane spectrum from the peak values at the other concentrations and determined the linear LSF among the eight values. 

If no absorption bands are present in the functional group region, with the exception of those arising from carbon-hydrogen stretching modes, consider the possibilities of ethers, alkyl halides, sulphur compounds, tertiary amines and nitro compounds as detailed in the sections below. 

The i.r. spectrum shows absorptions at c. 3050 and 2950 cm-1 for the aromatic and alkyl carbon-hydrogen stretching vibrations respectively, at... 

Note the characteristic absorptions for the aromatic system at c. 3050 cm-, at 1600, 1590 and 1500 cm-1 and at c. 700 and 765 cm-1 for a monosubstituted nucleus. The t-butyl group shows characteristic carbon-hydrogen stretching absorptions at c. 2950 cm-1. 

It is known that the optical absorption which is the major drawback of the classical plastic materials such as PMMA, is dominated by the higher harmonics of the carbon-hydrogen stretching vibrations. The value of polymers from 2,2-dichlorovinyl chloroformates derivatives has to do with their lower optical absorption as compared to standard plastics in the visible and near-infrared regions of the spectrum (0.6 to 1.5 J.m). Some new 1,2-dichlorovinyl carbonates prepared by standard procedures in 90-95 % yield for that purpose are gathered in table 3-19 (Ref. 169). 

The six individual carbon-hydrogen stretching oscillators in a benzene molecule combine to give the six C-H stretching normal modes of the molecule, as follows A v, 3062 cm ), (v, 3063 cm ), E2g... 

There are many published applications of the use of NIRA in processes such as qualitative and quantitative analysis of liquid phase systems. Organic solvents have very specific overtone bands in the first carbon-hydrogen stretching region from 1600-1800nm which can be exploited for their assay. There are also many applications for the monitoring... 

All hydrocarbons give absorption peaks in the 2800—3300-cm region that are associated with carbon—hydrogen stretching vibrations. 

The carbon-hydrogen stretching peaks of hydrogen atoms attached to /-hybridized carbon atoms occur at highest frequencies, about 3300 cm h... 

---