Infrared Unknown Identities
Spectrum at the Top of Page
3350 -- OH stetching vibrational frequency
2950 -- CH aliphatic asymmetrical stretching vibrational band. The less intense band at 2860 is the
symmetrical stretching vibrational band.
1425 -- CH2 characteristic absorption
1065 -- CO absorption
The compound is cyclohexanol.
Unknown #1
3100 -- The broad intense absorption band seen here is characteristic of a carboxylic acid dimer.
2960 -- CH aliphatic assymmetric stretch
2870 -- CH aliphatic symmetic stretching vibrational band.
1415 -- Absorption in this region is due to CH3. Note the weak band just below 1400. This is the
methyl bending vibrational band.
1290 -- Due to coupling of the in-plane OH bending and CO stretching of the dimer.
950 -- OH out-of-plane bending of the dimer.
The compound is octanoic acid
Unknown #2
3080 -- Aromatic CH absoprtion
2760 -- Aldehyde CH
1735 -- C=O absorption
1615 -- Carbonyl conjugated with the aromatic ring. The 1600 and 1500 bands for the aromatic
nucleus are variable.
1414 -- The methyl bending vibrational band (1380 cm-1).
820 -- 2-adjacent hydrogens on an aromatic ring. Para substitution.
The compound is p-tolualdehyde, 4-methylbenzaldehyde.
Unknown #3
3250 -- Hydrogen bonded OH.
3120 -- Aromatic CH.
2820 -- Aldehyde CH
1690 -- C=O
1600 & 1500 -- Aromatic nucleus.
1200 -- Phenol C-O absorption. The absorption for alcohols is primary, 1050, secondary, 1100 and
tertiary at 1150.
760 & 720 -- 4-adjacent hydrogens on an aromatic ring. Ortho substitution.
The compound is salicylaldehyde, 2-hydroxybenzaldehyde.
Unknown #4
3060 -- Aromatic CH
2960 & 2890 -- Asymmetric and symmetric stretching of aliphatic CH
1615 & 1510 -- Aromatic nucleus
1470 -- Aliphatic CH2 sissor for the methylene group.
745 &705 -- Pattern for five adjacent hydrogens on an aromatic ring. (Monosubstitution) Note the
overtones between 1660 & 2000.
The compound is diphenyl methane.
Unknown #5
2995 --Aliphatic CH symmetric and assymetric stretching vibration absorption.
1765 & 1740 -- C=0 Note the two minima of this band. Two carbonyls.
1380 -- CH3 bending vibrational band. The bands abrove 1400 are due also due to CH for methyl
and methylene.
1280 -- Asymmetric stretching for the C-O-C of the ester.Other bands in this region may be related
due to the complex nature of the molecule.
1045 -- Symmetric strectch for the C-O-C of the ester.
The compound is diethyl malonate.
Unknown #6
2960 & 2980 -- Asymmetric and symmetrical CH absorption
1480 -- Aliphatic CH2 sissor for the methylene group.
1395 -- These two peaks are characteristic of CH3.
The unknown is squalane, 2,6,10,15,19,23-hexamethyltetracosane, C30H62