Basis Set Effects in the Description of the Cl-O Bond in ClO and XClO/ClOX Isomers (X = H, O, and Cl) Using DFT and CCSD(T) Methods
Table 1
Enthalpy of reaction for reactions (1) and (2) and enthalpy of formation of ClO derived from these reactions using different models (in kcal/mol) and ClO bond length (in Å).
Method
Basis set
Cl + O⟶ClO
Cl2+O2⟶2ClO
Bond length
δa
δa
r
δa
MP2
6-31G(d,p)
−46.42
42.13
17.84
65.22
32.61
8.3
1.6088
0.0392
6–311++G(2df,2pd)
−56.99
30.59
6.44
68.76
34.38
10.2
1.5614
−0.0082
CCSD(T)
6-31G(d,p)
−48.13
39.45
15.30
47.24
23.62
−0.5
1.6287
0.0591
6–311++G(2df,2pd)
−56.95
30.63
6.48
52.17
26.08
1.9
1.5885
0.0189
aug-cc-pV6Z
−63.54
24.04
−0.11
49.82
24.91
0.8
1.5694
−0.0002
CBS-QB3
−63.47
24.11
−0.04
52.52
26.26
2.1
1.6102
0.0406
G4
−62.70
24.88
0.73
50.60
25.30
1.2
1.5925
0.0229
W1BD
−64.03
23.55
−0.60
49.61
24.80
0.7
1.5810
0.0114
PW91
6-31G(d,p)
−73.61
13.97
−10.18
49.76
24.88
0.7
1.5850
0.0154
6–311++G(2df,2pd)
−79.68
7.90
−16.25
47.43
23.72
−0.4
1.5848
0.0152
aug-cc-pV6Z
−81.37
6.21
−17.94
45.54
22.77
−1.4
1.5778
0.0082
TPSS
6-31G(d,p)
−64.48
23.10
−1.05
47.54
23.77
−0.4
1.5780
0.0084
6–311++G(2df,2pd)
−70.30
17.28
−6.87
45.69
22.84
−1.3
1.5778
0.0082
aug-cc-pV6Z
−71.71
15.87
−8.28
43.87
21.94
−2.2
1.5848
0.0152
B3LYP
6-31G(d,p)
−58.76
28.82
4.67
49.53
24.76
0.6
1.6195
0.0499
6–311++G(2df,2pd)
−64.48
23.10
−1.05
47.87
23.94
−0.2
1.5844
0.0148
aug-cc-pV6Z
−66.26
21.32
−2.83
45.98
22.99
−1.2
1.5736
0.0040
PBE0
6-31G(d,p)
−84.29
3.29
−20.86
51.77
25.88
1.7
1.5999
0.0303
6–311++G(2df,2pd)
−65.58
22.00
−2.15
50.57
25.29
1.1
1.5665
−0.0031
aug-cc-pV6Z
−67.38
20.20
−3.95
48.60
24.30
0.2
1.5563
−0.0133
M06
6-31G(d,p)
−58.66
28.92
4.77
51.26
25.63
1.5
1.5970
0.0274
6–311++G(2df,2pd)
−64.26
23.32
−0.83
50.34
25.17
1.0
1.5661
−0.0035
aug-cc-pV6Z
−65.54
22.04
−2.11
50.05
25.02
0.9
1.5563
−0.0133
M06-2X
6-31G(d,p)
−56.56
31.02
6.87
54.49
27.25
3.1
1.5967
0.0271
6–311++G(2df,2pd)
−62.91
24.67
0.52
53.35
26.67
2.5
1.5633
−0.0063
aug-cc-pV6Z
−64.38
23.20
−0.95
51.35
25.67
1.5
1.5545
−0.0151
BMK
6-31G(d,p)
−57.76
29.82
5.67
54.24
27.12
3.0
1.6199
0.0503
6–311++G(2df,2pd)
−63.79
23.79
−0.36
53.25
26.62
2.5
1.5842
0.0146
aug-cc-pV6Z
−65.36
22.22
−1.93
51.37
25.68
1.5
1.5693
−0.0003
B2PLYP
6-31G(d,p)
−54.20
33.38
9.23
52.43
26.21
2.1
1.6093
0.0397
6–311++G(2df,2pd)
−61.61
25.97
1.82
52.52
26.26
2.1
1.5758
0.0062
aug-cc-pV6Z
1.5631
−0.0065
−63.43
24.29b
48.30
24.29b
1.5695c
aDifference between the calculated value and the experimental value; b[32]; c[31].
