Supporting Information for:
1
H NMR Study of Hydrogen Abstraction in Model Compound
Mimics of Polymers
Jeffrey R. Lancaster1,2, Rachael Smilowitz2, Nicholas J. Turro1,2, Jeffrey T.
Koberstein2,*
1
. Department of Chemistry, Columbia University, 2. Department of Chemical
Engineering, Columbia University
Note: In the 1H NMR spectra for compounds 1-9 peaks for CH3CN (1.94), H2O (2.13),
and benzophenone (7.0-7.6) have not been labeled for the sake of clarity.
Methods for determination of bond dissociation energies from Luo, Y.-R. Handbook of
bond dissociation energies in organic compounds; CRC Press LLC, 2003.
a. Correlation
b. Polanyi correlation
c. Kinetics
d. Photobromination
e. Intersecting parabolas
f. Acidity-oxidation potential measurement
g. Very low pressure pyrolysis technique
h. Single-pulse shock tube technique
i. Electron impact
j. Reanalysis of pyrolysis data
k. Fourier transform ion cyclotron resonance spectrometry
l. Proton affinity
m. Review
n. Photoionization mass spectrometry
o. Resonance fluorescence detection
p. Appearance energy measurements
q. Laser flash photolysis
r. Derived from Hf°
s. Recommended
Caprolactam, 1
Figure S1a. 300 MHz 1H NMR spectra of a 96.9 mM solution of 1 (CD3CN) after 0 min
(bottom), 30 min (middle), and 120 min (top).
Figure S1b. Difference between 300 MHz 1H NMR spectra of 1 (CD3CN) before and
after 120 min irradiation at 350nm.
Figure S1c. Plot of decreasing 1H NMR integrals scaled by initial integral and number of
protons with increasing irradiation time of 1. Each set of data is fit by y = Ae-kt + C.
Table S1. Compounds with representative bond dissociation energies for the hydrogen
atoms of 1, the relation of each representative bond to 1, and the competitive rate value of
k/ka scaled for the number of hydrogen atoms.
X-H BDE
Representative compound
Relation to 1
k/ka
(kcal/mol)
N,N-dimethylacetamide
91.0a
Ha
1
cycloheptane
93.3b
94.0c
92.5±1d
96.5e
Hb
0.28
N-isopropylacetamide
93.1a
Hc
1.13
2-piperidone
109.5f
Hd
2.19
Methyl-caprolactam, 2
Figure S2a. 300 MHz 1H NMR spectra of a 92.3 mM solution of 2 (CD3CN) after 0 min
(bottom), 30 min (middle), and 120 min (top).
Figure S2b. Difference between 300 MHz 1H NMR spectra of 2 (CD3CN) before and
after 120 min irradiation at 350nm.
Figure S2c. Plot of decreasing 1H NMR integrals scaled by initial integral and number of
protons with increasing irradiation time of 2. Each set of data is fit by y = Ae-kt + C.
Table S2. Compounds with representative bond dissociation energies for the hydrogen
atoms of 2, the relation of each representative bond to 2, and the competitive rate value of
k/ka scaled for the number of hydrogen atoms.
X-H BDE
Representative compound
Relation to 2
k/ka
(kcal/mol)
N,N-dimethylacetamide
91.0a
Ha
1
cycloheptane
93.3b
94.0c
92.5±1d
96.5e
Hb
0.36
N-isopropylacetamide
93.1a
Hc
0.90
methylamine
93±2.5g
96.6h
93.9±2i
88.7g
Hd
0.75
-Caprolactone, 3
Figure S3a. 300 MHz 1H NMR spectra of a 95.7 mM solution of 3 (CD3CN) after 0 min
(bottom), 30 min (middle), and 120 min (top).
Figure S3b. Difference between 300 MHz 1H NMR spectra of 3 (CD3CN) before and
after 120 min irradiation at 350nm.
Figure S3c. Plot of decreasing 1H NMR integrals scaled by initial integral and number of
protons with increasing irradiation time of 3. Each set of data is fit by y = Ae-kt + C.
Table S3. Compounds with representative bond dissociation energies for the hydrogen
atoms of 3, the relation of each representative bond to 3, and the competitive rate value of
k/ka scaled for the number of hydrogen atoms.
X-H BDE
Representative compound
Relation to 3
k/ka
(kcal/mol)
ethyl propanoate
95.6j
Ha
1
cycloheptane
93.3b
94.0c
92.5±1d
96.5e
Hb
1.33
-caprolactone
92.8±2.4k
Hc
5
Sec-butylbenzene, 4
Figure S4a. 300 MHz 1H NMR spectra of a 88.6 mM solution of 4 (CD3CN) after 0 min
(bottom), 30 min (middle), and 120 min (top). Signals from the aromatic protons of 4
overlap adduct proton signals in the region 7.0-7.4.
Figure S4b. Difference between 300 MHz 1H NMR spectra of 4 (CD3CN) before and
after 120 min irradiation at 350nm. Signals from the aromatic protons of 4 overlap adduct
proton signals in the region 7.0-7.4.
Figure S4c. Plot of decreasing 1H NMR integrals scaled by initial integral and number of
protons with increasing irradiation time of 4. Each set of data is fit by y = Ae-kt + C.
Table S4. Compounds with representative bond dissociation energies for the hydrogen
atoms of 4, the relation of each representative bond to 4, and the competitive rate value of
k/ka scaled for the number of hydrogen atoms.
X-H BDE
Representative compound
Relation to 4
k/ka
(kcal/mol)
84.6g
86.2l
ethylbenzene
85.4±1.5m
Ha
1
90.3j
87.0e
tert-butylbenzene
butane
butane
98.7a
99.1±0.4n
98.3±0.5o
98.6±0.5m
98.3±0.5n
97.4±1.0h
101±2i
100.2p
100.7h
101.7±0.5n
Hb
0.39
Hc
0.52
Hd
0.35
Ethylbenzene, 5
Figure S5a. 300 MHz 1H NMR spectra of a 81.7 mM solution of 5 (CD3CN) after 0 min
(bottom), 30 min (middle), and 120 min (top). Signals from the aromatic protons of 5
overlap adduct proton signals in the region 7.0-7.4.
Figure S5b. Difference between 300 MHz 1H NMR spectra of 5 (CD3CN) before and
after 120 min irradiation at 350nm. Signals from the aromatic protons of 5 overlap adduct
proton signals in the region 7.0-7.4.
Figure S5c. Plot of decreasing 1H NMR integrals scaled by initial integral and number of
protons with increasing irradiation time of 5. Each set of data is fit by y = Ae-kt + C.
Table S5. Compounds with representative bond dissociation energies for the hydrogen
atoms of 5, the relation of each representative bond to 5, and the competitive rate value of
k/ka scaled for the number of hydrogen atoms.
X-H BDE
Representative compound
Relation to 5
k/ka
(kcal/mol)
84.6g
86.2l
ethylbenzene
85.4±1.5m
Ha
1
90.3j
87.0e
tert-butylbenzene
98.7a
Hb
0.25
Methyl trimethylacetate, 6
Figure S6a. 300 MHz 1H NMR spectra of a 81.4 mM solution of 6 (CD3CN) after 0 min
(bottom), 120 min (middle), and 360 min (top).
Figure S6b. Difference between 300 MHz 1H NMR spectra of 6 (CD3CN) before and
after 360 min irradiation at 350nm.
Figure S6c. Plot of decreasing 1H NMR integrals scaled by initial integral and number of
protons with increasing irradiation time of 6. Each set of data is fit by y = Ae-kt + C.
Table S6. Compounds with representative bond dissociation energies for the hydrogen
atoms of 6, the relation of each representative bond to 6, and the competitive rate value of
k/ka scaled for the number of hydrogen atoms.
X-H BDE
Representative compound
Relation to 6
k/ka
(kcal/mol)
acetic acid
methyl ester
96.7a
Ha
1
2,2-dimethylpropanoic acid
99.2a
Hb
2.22
2,2-Dimethylbutane, 7
Figure S7a. 300 MHz 1H NMR spectra of a 98.6 mM solution of 7 (CD3CN) after 0 min
(bottom), 30 min (middle), and 120 min (top).
Figure S7b. Difference between 300 MHz 1H NMR spectra of 7 (CD3CN) before and
after 120 min irradiation at 350nm.
Figure S7c. Plot of decreasing 1H NMR integrals scaled by initial integral and number of
protons with increasing irradiation time of 7. Each set of data is fit by y = Ae-kt + C.
Table S7. Compounds with representative bond dissociation energies for the hydrogen
atoms of 7, the relation of each representative bond to 7, and the competitive rate value of
k/ka scaled for the number of hydrogen atoms.
X-H BDE
Representative compound
Relation to 7
k/ka
(kcal/mol)
99.1±0.4n
98.3±0.5o
butane
98.6±0.5m
Hb
1
98.3±0.5n
97.4±1.0h
99.4±1b
100.3±1c
neopentane
99.4±1h
Ha
m
101.0±2
101.1q
0.38
i
101±2
100.2p
butane
Hc
100.7h
101.7±0.5n
Trans-3-hexene, 8
Figure S8a. 300 MHz 1H NMR spectra of a 85.2 mM solution of 8 (CD3CN) after 0 min
(bottom), 30 min (middle), and 60 min (top).
Figure S8b. Difference between 300 MHz 1H NMR spectra of 8 (CD3CN) before and
after 60 min irradiation at 350nm.
Figure S8c. Plot of decreasing 1H NMR integrals scaled by initial integral and number of
protons with increasing irradiation time of 8. Each set of data is fit by y = Ae-kt + C.
Table S8. Compounds with representative bond dissociation energies for the hydrogen
atoms of 8, the relation of each representative bond to 8, and the competitive rate value of
k/ka scaled for the number of hydrogen atoms.
X-H BDE
Representative compound
Relation to 8
k/ka
(kcal/mol)
109±2.4h
propene
111.1h
Ha
1
Hb
3.13
Hc
2.08
81.7±1.5r
(E)-2-pentene
butane
82.5a
101±2i
100.2p
100.7h
101.7±0.5n
Butyl isovalerate, 9
Figure S9a. 300 MHz 1H NMR spectra of a 89.2 mM solution of 9 (CD3CN) after 0 min
(bottom), 30 min (middle), and 180 min (top).
Figure S9b. Difference between 300 MHz 1H NMR spectra of 9 (CD3CN) before and
after 180 min irradiation at 350nm.
Figure S9c. Plot of decreasing 1H NMR integrals scaled by initial integral and number of
protons with increasing irradiation time of 9. Each set of data is fit by y = Ae-kt + C.
Table S9. Compounds with representative bond dissociation energies for the hydrogen
atoms of 9, the relation of each representative bond to 9, and the competitive rate value of
k/ka scaled for the number of hydrogen atoms.
X-H BDE
Representative compound
Relation to 9
k/ka
(kcal/mol)
propanol
97.1±2p
Ha
Hg
1
propanol
97.1±2p
Hb
4.26
propanol
94.3±2p
Hc
4.26
acetic acid
isopropyl ester
93.8a
Hd
3.19
ethyl
propanoate
95.6j
He
7.45
isobutane
95.6±0.7h
95.0g
95.5±0.7o
95.5±0.3o
95.7±0.7s
Hf
7.45