3.9 Thiols and Sulfides
67
3.9 Thiols and Sulfides
Assignment
Range
Comments
al C–S
ar C–S
5–60 ppm
120–140 ppm
No significant shift with respect to C–C
HS–C al
1.0–2.0 ppm
Vicinal coupling constant, J, 5–9 Hz
HS–C ar
2.0–4.0 ppm
al CH–S
2.0–3.2 ppm
ar CH–S
7.0–7.5 ppm
S–H st
2600–2540 cm -1 Frequently weak
Molecular ion
34 S-isotope peak at [M+2] +· ≈4.5%
Aliphatic: intensity higher than for corresponding alcohols and ethers
Fragments
m/z 47, 61, 75, … Sulfide cleavage:
R 1 S CH 2 R 2
- R 2
.
R 1 S CH 2
+
+ .
Rearrangements
m/z 34, 35, 48
[M-33] +
[M-34] +·
Alkene elimination after sulfide cleavage
Aliphatic
<225 nm (log ε 3–4)
220–250 nm (log ε 2–3)
13 C
1 H
IR
MS
UV
67
3.9 Thiols and Sulfides
Assignment
Range
Comments
al C–S
ar C–S
5–60 ppm
120–140 ppm
No significant shift with respect to C–C
HS–C al
1.0–2.0 ppm
Vicinal coupling constant, J, 5–9 Hz
HS–C ar
2.0–4.0 ppm
al CH–S
2.0–3.2 ppm
ar CH–S
7.0–7.5 ppm
S–H st
2600–2540 cm -1 Frequently weak
Molecular ion
34 S-isotope peak at [M+2] +· ≈4.5%
Aliphatic: intensity higher than for corresponding alcohols and ethers
Fragments
m/z 47, 61, 75, … Sulfide cleavage:
R 1 S CH 2 R 2
- R 2
.
R 1 S CH 2
+
+ .
Rearrangements
m/z 34, 35, 48
[M-33] +
[M-34] +·
Alkene elimination after sulfide cleavage
Aliphatic
<225 nm (log ε 3–4)
220–250 nm (log ε 2–3)
13 C
1 H
IR
MS
UV