Hydrogen bending

Table 1. Infrared Absorbances for Selected Carbon-Hydrogen Bending Modes...

It has bean claimed that there is characteristic oxazirane absorption in the infrared at 6. -7.0 p.11 However, since the carbon-hydrogen bending vibration of alkyl groups appears in this same region, this is a... 

In the hydrogen bending region, deuteration studies [Peraldo (167) Natta (150) ] indicate that the 1437 cm-1 a band is associated with the CHg group, thus suggesting its assignment to 8 (CH2) (E). This would then require that the 1453 n and 1461 a bands be assigned to 8a (CH3) ( 4) and... 

TABLE 13-22 Hydrogen Bending Classification of Chemical Families... 

In-plane hydrogen bending modes fall in the spectral region 1000-1700 cm . 

Carbon-hydrogen bending in alkenes and aromatic riqgs is both in-plane and out-of-plane, and of these the latter kind is more useful For alkenes, out-of-plane... 

FIGURE 14.11. Schematic illustration of the guanidinium-phosphate interaction. This specific interaction is made up of electrostatic interactions and hydrogen bending [19]. 

The simplest example of self-association in the vapor phase is dimerization, as exemplified by hydrogen bending in carboxylic acids. Consider the dimerization of acetic acid ... 

What is present is a band 1430-14 70 cm that indicates carbon-hydrogen bending for methyl and methylene groups. Also, the small band at 1375 cm confirms the methyl. R can only be CH3CH2CH2, so that C5H10 is CH3CH2CH2CH=CH2, or 1-pentene. 

It Is a familiar observation in vibrational spectroscopy that a hydrogen bending or deformation vibration has a fundamental frequency approximately half that of the hydrogen stretching modes. It may then happen that cubic enharmonic interaction terms in the potential couple the stretching mode to the overtone of the bending mode. The terms concerned will be of the type... 

Absorptions arising from carbon—hydrogen bending vibrations of alkenes occur in the 600—1000-cm region. With the aid of a spectroscopy handbook, the exact location of these peaks can often be used as evidence for the substitution pattern of the double bond and its configuration. 

---