IR scans/ vibrational frequencies Flashcards
Give a frequency and description of the IR spectrum of C-C
Around 1000
Not really used
Give a frequency and description of the IR spectrum of C=C
Around 1660
Small-Medium Intensity
Give a frequency and description of the IR spectrum of C≡C
Around 2150
Small-Medium Intensity with sharp peaks
Give a frequency of the IR spectrum of C-H (sp3)
Less than 3000
Give a frequency of the IR spectrum of C-H (sp2)
Greater than 3000
Give a frequency of the IR spectrum of C-H (sp)
Greater than 3000
Give a frequency and description of the IR spectrum of C=O
Around 1700
Very high intensity, dominates the spectrum
Give a frequency and description of the IR spectrum of C-O
Around 1200
Less than C=O, due to the single bond
Give a frequency and description of the IR spectrum of O-H
Huge range from 3500-3600
Dilute will be higher, very broad peak
Give a frequency and description of the IR spectrum of N-H
Range from 3500-3300
N has less EN-> smaller wavenumbers
Give a frequency and description of the IR spectrum of C≡N
Around 2250
Small-Medium Intensity peaks that are relatively sharp
Relate H-bonding, wave number, and peak
The more H-Bonding, the lower the wavenumber because H-Bonding weakens the O-H bond by pulling away some electron density. Concentrated solutions or carboxylic acids have more H-Bonding and lower wavenumbers. More H-Bonding also broadens the peak. O-H peaks in general are broader.
How many peaks will Primary, Secondary, and Tertiary Amines have in the N-H range?
Two, one, or zero peaks
What vibrational frequency is around 1660 and has small-medium intensity peaks?
C=C
What vibrational frequency is around 2250 and has peaks that are small-medium intensity that are relatively sharp?
C(triple bond)N
