IR Spectroscopy and Carbonyl Absorption

Where do bonds to hydrogen occur within the spectrum?

2700 - 4000

Where do triple bonds occur?

2100 - 2500

Where do double bonds occur?

1500 - 1800

Where do single bonds occur?

0 - 1500

Where does Csp3 - H occur?

2850 - 2960 (right before the 3000 line)

Csp2- H?

3020 - 3100 (right after the 3000 line)

what has overtones that are sometimes seen? 

Arenes. they look like tiny fangs in the double bond region

Arene peak location?

1450 - 1600 (prob blends into 1500 line)

Alcohol has a _____ shape?

A U shape

Carboxylic has a ______ shape?

Broader dip. likely stretches across the 3000 line.

thicker width in the fingerprint range?

likely a C-O single bond

Where is an aldehyde H-C--O (C double bonded to O) located? 

2850

Two long fans in H bond region?

prob N-H and with two of them, it is indicating NH2

Monosub double bonded C to C?

910 and 990

If there is resonance…

the C double bonded to O will occur at a lower frequency

If an atom adjacent to a C double bonded to O is highly electronegative…..

the bond will occur at a HIGHER FREQ.

As angle strain increases, the C double bonded to O will occur at a ….

HIGHER FREQ.