IR Spectrom Alkenes

IR Spectrum of Alkenes Has C-H bunds, also has Sharp, medium bands corresponding to C=C bond stretching Vibration at about 1600- 1700 un Some alkenes might also show a band for the C-H bond Stretch, appearing around 3080 cm-1. However, this band would be obscured by the broader bands appearing around 3000 und IR Spectrum of Alkynes The most prominent band in alkynes the corresponds to Carbon-Carbon triple bond - It shows as a sharp, weak band at about 2100 cm-1 . The reason it's weak is because the triple bund is not very Polar. In some cases, such as in highly symmetrical alkyne, it may not Show at all due to the low polarity of the triple bond associated with those alkynes. Terminal alkynes / that is to say those where the priple bond is at the end of a carbon chain have C-H bonds involving the sp carbon (the carbon that forms part of the triple bond). Therefore they may also Show a sharp, weak band at about 3300 m corresponding to the C-H Stretch. Internal alkynes ,that Ps those where the triple bond is in the middle of a carbon chain do not have C-H bonds to

The finger Print Region Although the entire IR spectrum can be used as a finger print for the purposes of comparing molecules, 600-1400um is called finger print region. This is normally a complex area showing many band, frequently overlapping each other This complexity limits its use to that of a finger print and should be ignored by beginner when analyzing the spectmen IR Spectrum of Alkanes Alkanes - . No functional gp. IR spectrum only displays only C-C and C-H bonds- Vibrations Most useful is the C-H bands that appear around 3000 cm+ Since most organic molecules have Such bonds, most organic molecule will display those bands in then Spectrum