National Institute of Standards and Technology

Computational Chemistry Comparison and Benchmark DataBase
Release 22	May 2022
NIST Standard Reference Database 101

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III	Calculated data
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XX	H-bond dimers
XXI	Oddities

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II.B.6.

Experimental Barriers to Internal Rotation for CH₃COCH₂CH₃ (2-Butanone)

Data from:
1991Dur/Fen:1827
JR Durig, FS Feng, A Wang, HV Phan "Conformational stability, barriers to internal rotation, ab initio calculations, and vibrational assignment of 2-butanone" Can. J. of Chem. 69(11) 1845-1856, 1991
V1=652+-68, V2=70+-50, V3=356+-25 cm^-1

torsion index	Angle	Energy (kJ mol-1)	Energy (cm-1)
1	0	12.06	1008
1	15	11.36	949
1	30	9.62	804
1	45	7.70	644
1	60	6.48	541
1	69.7	6.26	523
1	75	6.31	528
1	90	6.87	574
1	105	7.31	611
1	106.3	7.31	611
1	120	6.84	571
1	135	5.20	434
1	150	2.86	239
1	165	0.81	68
1	180	0.00	0
1	195	0.81	68
1	210	2.86	239
1	225	5.20	434
1	240	6.84	571
1	253.7	7.31	611
1	255	7.31	611
1	270	6.87	574
1	285	6.31	528
1	290.3	6.26	523
1	300	6.48	541
1	315	7.70	644
1	330	9.62	804
1	345	11.36	949
1	360	12.06	1008
2	0	10.38	868
2	15	8.86	741
2	30	5.19	434
2	45	1.52	127
2	60	0.00	0
2	75	1.52	127
2	90	5.19	434
2	105	8.86	741
2	120	10.38	868
2	135	8.86	741
2	150	5.19	434
2	165	1.52	127
2	180	0.00	0
2	195	1.52	127
2	210	5.19	434
2	225	8.86	741
2	240	10.38	868
2	255	8.86	741
2	270	5.19	434
2	285	1.52	127
2	300	0.00	0
2	315	1.52	127
2	330	5.19	434
2	345	8.86	741
2	360	10.38	868
3	0	2.79	233
3	15	2.38	199
3	30	1.39	116
3	45	0.41	34
3	60	0.00	0
3	75	0.41	34
3	90	1.39	116
3	105	2.38	199
3	120	2.79	233
3	135	2.38	199
3	150	1.39	116
3	165	0.41	34
3	180	0.00	0
3	195	0.41	34
3	210	1.39	116
3	225	2.38	199
3	240	2.79	233
3	255	2.38	199
3	270	1.39	116
3	285	0.41	34
3	300	0.00	0
3	315	0.41	34
3	330	1.39	116
3	345	2.38	199
3	360	2.79	233

Atoms in torsion 1 are 1, 2, 3, 4
The rotor type is CH₂CH₃

Atoms in torsion 2 are 9, 4, 3, 2
The rotor type is CH₃
methyl on ethyl

Atoms in torsion 3 are 6, 1, 2, 3
The rotor type is CH₃
methyl on CO

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