CHEM 6AL Lecture Notes - Lecture 7: Ketone, Alkane, Double Summit
Document Summary
Iq: what functional group is present in this ir spectrum? (alcohol ir spectrum) No carbonyl (no stretch between 1700-(cid:883)8(cid:882)(cid:882)) can"t be carboxylic acid/ester. If there is a little peak, more likely to be an alkyne. Intense peak between 1700-1800 to have a carbonyl. Amine usually has double peak within the peak. Terminal alkyne has distinct c-h peak (~3200) One peak may be strong other may be not as strong, as long as in 1500-1300 cm^-1. Intensity of absorption band dependent on dipole moment. Alcohol: 3650-3200 cm^-1 (broad & strong stretch) Acid: 3300-2250 cm^-1 (very broad, medium intensity) N-h bonds medium intensity & narrower than alcohols. Sp: ~3300 sp^2 (alkene) ~3100-3020 cm^-1 sp^2 (aldehyde) 2800-2700 sp^3: 2950-2850 cm^-1. Cn: ~2260-2200 (more intense; medium intensity; stronger dipole) How to analyze an ir spectrum: look at double bond region (1850-1630) If nothing else, probably a ketone: look at oh nh region.
