Organic Chemistry Spectrums

What can be found in the 650 to 1550 region of IR?

What can be found in the 650 to 1550 region of IR?

• C bonded to heteroatom, increasing frequency with increasing electronegativity

• C single bonded to C

• C single bonded to O

• One of the N double bonded to O peak

What can be found in the 1550 to 1650 region of IR?

• C double bonded to N

• C double bonded to C

• N double bonded to O

What can be found in the 1800 to 1650 region of IR?

• C double bonded to oxygen

• Arene

What can be found in the 1800 to 2000 region of IR?

Nothing very cool

What can be found in the 2000 to 2500 region of IR?

• C triple bonded to C

• C triple bonded to N

• X double bonded to C double bonded to Y

What can be found in the 2500 to 4000 region of IR?

• C bonded to H

• O bonded to H

• N bonded to H

Where is Sp3 C-H found?

Sp2 C-H?

Sp C-H?

• Sp3 C-H: 2850-3000

• Sp2 C-H: 3000- 3100

• Sp C-H: 3300

Give the base value for absorption for O-H in IR

3400

Give the base value for absorption for N-H in IR

3400

Give the base value for absorption for C-H in IR

3000

Give the base value for absorption for C triple bonded to N in IR

2250

Give the base value for absorption for C triple bonded to C in IR

2150

Give the base value for absorption for C double bonded to O in IR

1715

Give the base value for absorption for C double bonded to C in IR

1650

Give the base value for absorption for C-O in IR

1100

What is the order of things you look at for IR?

1.) C double bonded O

2.) Double bonds/rings

3.) Triple bonds

4.) Nitro groups

5.) Aliphatic Hydrocarbons

Which gives a stronger peak, OH with hydrogen bonding or without?

OH without hydrogen bonding

How many peaks does a primary amine have? secondary? tertiary?

Primary: 2 peaks

Secondary: 1 peak

tertiary: no peaks

As ring size increases and angle strain decreases the frequency increases/decreases

increases

Resonance increases/decreases frequency

decreases

An atom is NMR active if it has an odd or even mass number, odd or even atomic number or both has a spin and a resulting nuclear magnetic moment.

Odd mass number, Odd atomic number

Upfield is the left or right of the spectrum? Does it have shielding or disheilding?

Right, Sheilding

Downfield is the left or right of the spectrum? Does it have shielding or deshielding?

Left, deshielding

What compound is given a resonance frequency of 0?

TMS

What can be found in the NMR region of 1-2? (Give in increasing order)

Alkyl CH3

Alkyl CH2

Alkyl CH

What can be found in the NMR region of 1.6-2.6? (Give in increasing order)

• Allylic CH (Next to double bond)

• Benzyllic CH (Next to ring)

• Ketone (next to carbonyl group)

What can be found in the NMR region of 1.7-3.1? (Give in increasing order)

Alkyne (CH on triple bond)

What can be found in the NMR region of 3-4? (Give in increasing order)

• CH next to heteroatom, the more electronegative, the lower the ppm

• Ether

• Alcohol

What can be found in the NMR region of 5-6? (Give in increasing order)

• Terminal Alkene

• Internal Alkene

What can be found in the NMR region of 7-8? (Give in increasing order)

Aromatic ring hydrogen

What can be found in the NMR region of 9-10? (Give in increasing order)

Aldehyde hydrogen

What can be found in the NMR region of 11-12? (Give in increasing order)

Carboxylic Hydroxy RCOOH

What can be found in C NMR region of 0-77?

Sp3 carbons

What can be found in C NMR region of 77-100?

Sp carbons

What can be found in C NMR region of 110-150?

sp2 carbons in a alkene (Double bonds) and aromatic rings

What can be found in C NMR region of 160-220?

Sp2 carbons in a carbonyl group

Where are carboxylic acids and carboxylic esters found on C NMR?

160-185

Where are aldehydes and ketones found on C NMR?

190-220

How do you calculate chemical shifts of ppm for an instrument?

Difference from TMS resonance frequency/NMR instrument frequency

Give the coupling constant for cis alkenes

6-12

Give the coupling constant for trans alkenes

12-18

Give the coupling constant for geminal alkenes

0-3