University:
Swansea University
Course:
PM134 | Microbiology
Academic year:

2023
Views:

290

Pages:

3
Author:

Sanjeev K

CLASSIFICATION OF IR BANDS IR bands depending be classified 03 Strong (3), medium (m) or weak (w), on their relative intensitice in the infrared spectrum, A strony band covore most of the y-aris. to A medium band falls about haff of the y-axis, and a weak bard falls to ans about one third or less of the y-axis Transmission 100/ f Wiak Medium Strong 01. INFRARED ACTIVE BONDS Not all Covalent bonde display bands in the IR Spectrum Only Polar bonds do so. There are refoored to as IR active The intensity of the bande depende on the magnitude of the depose moment associated with the bond in question: Strongly polar bonds such as carbonyl gps (c=0) produce Strong bands. Medium Polarity bonds and asymmetre bonde Produs medium bonde Weakly Polos bonde and symmetre bonde produse weak/non observable bands (Cartony1) uhila) HC=C-CH3 H-CEC-CH Not -CEN Medium Weak Obsonable Strong (propyne) (2-bityre ۲۶ INFRARED BAND SHAPES Infrared band shapes come in various forms. Two of the most common are narrow and broad. Narrow bands are thin and pointed, like a wide and smoother. dagger. Broad bands are Ex. O-H bonds, such as → broad and Carboxylic audes band thoose found in alwhols 100%-f Information obtained from IR Specha -IR is most useful in providing information about the pruence or absence of specific functional groups IR can provide a Molecular finger print that can be wend when comparing samples of two pure samples display the same IR spectrum it can be argued that they core the same compound. →IR does not provide detailed information or proof of molecular formula /structive. H provides information on moleculca fragment Speufially functional gps. →Therefore it is very limited in sope, and must be used in conjunction with other techniques to provide a more complete Picture of the moleculas Structure. IR Absorption Range The typical IR absorption range for covalent bond Bs 600-40000 Sharp band around 2200-2400 um- C-N/C-C triple bond. Type of bond Iklave no:(em-1) Intensity