Table 1 Thermodynamic parameters for the most stable enol to keto tautomers of b-ketoesters and AA compounds
|
|
matera
|
ΔEa
|
ΔE0a
|
ΔHa
|
ΔGa
|
ΔSa
|
Keqb
|
%enol
|
m
|
AA
|
Gas
|
AU1-I
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0013
|
99.9
|
3.3
|
CCl4
|
AU1-I
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0044
|
99.6
|
3.8
|
CH3CN
|
AU1-I
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0233
|
97.7
|
4.5
|
Gas
|
K1
|
22.4
|
19.6
|
20.9
|
16.5
|
14.7
|
|
|
1.6
|
CCl4
|
K1
|
18.6
|
16.2
|
17.4
|
13.4
|
13.3
|
|
|
1.8
|
CH3CN
|
K1
|
14.1
|
12.1
|
13.3
|
9.3
|
13.5
|
|
|
2.1
|
MAA
|
Gas
|
AU1-I
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0412
|
92.8
|
1.9
|
CCl4
|
AU1-I
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|
0.2387
|
61.2
|
2.1
|
CH3CN
|
AU1-I
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|
3.1574
|
6.4
|
2.5
|
Gas
|
K1
|
17.8
|
14.4
|
15.9
|
8.2
|
25.9
|
0.0358
|
|
2.4
|
CCl4
|
K1
|
13.3
|
10.2
|
11.8
|
3.5
|
27.6
|
0.3940
|
|
2.6
|
CH3CN
|
K1
|
7.4
|
4.8
|
6.4
|
-2.8
|
31.1
|
11.5394
|
|
2.3
|
Gas
|
K2
|
19.2
|
14.7
|
16.8
|
7.9
|
29.7
|
|
|
3.2
|
CCl4
|
K2
|
12.4
|
8.5
|
10.3
|
2.3
|
26.9
|
|
|
3.8
|
|
CH3CN
|
K2
|
2.8
|
-0.6
|
1.2
|
-6.1
|
24.3
|
|
|
4.8
|
EAA
|
Gas
|
AU1-I
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0166
|
97.3
|
2.1
|
CCl4
|
AU1-I
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0995
|
77.7
|
2.3
|
CH3CN
|
AU1-I
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|
3.4404
|
11.7
|
2.7
|
Gas
|
AU2-I
|
1.7
|
2.4
|
2.1
|
2.8
|
-2.6
|
0.011
|
|
1.9
|
CCl4
|
AU2-I
|
2.1
|
2.7
|
2.4
|
3.1
|
-2.2
|
0.1868
|
|
2.1
|
CH3CN
|
AU2-I
|
2.6
|
3.1
|
2.9
|
3.4
|
-1.7
|
4.1327
|
|
2.5
|
gas
|
K1
|
20.8
|
16.8
|
18.6
|
10.1
|
28.4
|
|
|
3
|
CCl4
|
K1
|
14.8
|
11.3
|
12.9
|
5.7
|
24.2
|
|
|
3.5
|
CH3CN
|
K1
|
5.8
|
2.6
|
4.3
|
-3.1
|
24.7
|
|
|
4.6
|
gas
|
K2
|
21.3
|
17.3
|
19.0
|
11.2
|
26.4
|
|
|
3.2
|
CCl4
|
K2
|
14.8
|
11.0
|
12.8
|
4.1
|
28.9
|
|
|
3.7
|
CH3CN
|
K2
|
5.5
|
2.3
|
4.0
|
-3.5
|
25.3
|
|
|
4.8
|
EMA
|
gas
|
AU1-I
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0208
|
95.7
|
2.4
|
CCl4
|
AU1-I
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|
0.2047
|
63.4
|
2.7
|
CH3CN
|
AU1-I
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|
3.7277
|
12.8
|
3.2
|
gas
|
AU2-I
|
1.7
|
2.4
|
2.1
|
4.0
|
-6.3
|
0.0115
|
|
2.2
|
CCl4
|
AU2-I
|
2.2
|
2.8
|
2.5
|
3.5
|
-3.2
|
0.2039
|
|
2.5
|
CH3CN
|
AU2-I
|
2.7
|
3.4
|
3.1
|
4.3
|
-4.3
|
0.9682
|
|
3
|
gas
|
K1
|
12.0
|
10.2
|
10.6
|
9.6
|
3.5
|
0.0128
|
|
3.7
|
CCl4
|
K1
|
7.6
|
6.2
|
6.7
|
3.9
|
9.2
|
0.1211
|
|
4.3
|
CH3CN
|
K1
|
0.7
|
-0.2
|
0.3
|
-3.3
|
12.0
|
2.1357
|
|
5.4
|
gas
|
K2
|
12.6
|
11.3
|
11.6
|
11.1
|
1.8
|
|
|
1.9
|
CCl4
|
K2
|
8.7
|
7.4
|
8.0
|
3.9
|
13.6
|
|
|
1.9
|
CH3CN
|
K2
|
2.2
|
1.4
|
2.0
|
0.08
|
6.3
|
|
|
1.9
|
|
gas
|
K3
|
12.4
|
11.1
|
11.4
|
10.8
|
2.0
|
|
|
1.7
|
|
CCl4
|
K3
|
8.6
|
7.4
|
8.0
|
5.2
|
8.9
|
|
|
1.7
|
|
CH3CN
|
K3
|
2.6
|
1.3
|
2.1
|
-1.9
|
13.5
|
|
|
2.1
|
EBA
|
Gas c
|
AU1-I
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0104
|
95.5
|
2.1
|
CCl4 c
|
AU1-I
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|
0.4792
|
75.8
|
2.4
|
CH3CN c
|
AU1-I
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|
1.1287
|
12.1
|
2.9
|
gas c
|
AU2-I
|
1.8
|
2.4
|
2.1
|
2.9
|
-2.6
|
0.0287
|
|
1.9
|
CCl4 c
|
AU2-I
|
2.2
|
2.8
|
2.3
|
3.5
|
-3.3
|
0.2095
|
|
2.3
|
CH3CN c
|
AU2-I
|
2.7
|
3.3
|
2.7
|
4.7
|
-5.9
|
5.2323
|
|
2.8
|
gas c
|
K1
|
17.3
|
14.7
|
16.0
|
11.3
|
15.5
|
0.0076
|
|
3.6
|
CCl4
|
K1
|
11.6
|
9.6
|
10.7
|
7.5
|
10.5
|
0.0613
|
|
4.2
|
CH3CN c
|
K1
|
4.0
|
2.5
|
3.2
|
-0.3
|
12.6
|
0.8859
|
|
5.1
|
gas c
|
K2
|
17.3
|
12.6
|
14.0
|
8.8
|
21.3
|
|
|
3.7
|
CCl4
|
K2
|
9.0
|
6.7
|
7.9
|
3.9
|
13.4
|
|
|
4.3
|
CH3CN c
|
K2
|
0.8
|
-1.1
|
-0.2
|
-1.1
|
13.8
|
|
|
5.3
|
gas c
|
K3
|
17.8
|
15.4
|
16.5
|
12.1
|
15.7
|
|
|
3.7
|
CCl4
|
K3
|
11.6
|
9.5
|
10.6
|
6.9
|
12.4
|
|
|
4.3
|
CH3CN d
|
K3
|
3.6
|
2.3
|
2.9
|
0.3
|
9.6
|
|
|
5.3
|
BAA
|
gas c
|
AU1-I
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|
0.057
|
94.6
|
2.3
|
CCl4
|
AU1-I
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|
0.068
|
93.6
|
2.5
|
CH3CN
|
AU1-I
|
0.0
|
0.0
|
0.0
|
0.0
|
0.0
|
1.56
|
39.0
|
2.8
|
gas
|
AU2-I
|
0.2
|
1.2
|
0.7
|
3.6
|
-9.6
|
|
|
1.8
|
CCl4
|
AU2-I
|
1.5
|
2.2
|
1.8
|
3.9
|
-7.1
|
|
|
2.5
|
CH3CN
|
AU2-I
|
3.0
|
3.2
|
3.1
|
1.7
|
4.7
|
|
|
2.4
|
gas c
|
K1
|
17.0
|
13.4
|
15.8
|
7.1
|
27.0
|
|
|
3.3
|
CCl4
|
K1
|
14.2
|
11.6
|
12.8
|
6.6
|
20.7
|
|
|
3.7
|
CH3CN c
|
K1
|
9.6
|
4.0
|
8.0
|
-1.1
|
22.0
|
|
|
5.6
|
a. All calculations has been performed at the B3lyp /6-311++G** level; ΔE, electronic energy, ΔE0, zero-point corrected energy, ΔG; and Gibbs free energy (kJ.mol-1), ΔS, entropy (in J mol-1 K-1), µ, dipole moment (in Debye); respectively.
b. Keq =exp(-DG/RT)
c. obtained from Ref.[5]
d. obtained from Ref.[4]
Table 2 The geometrical and topological parameters of the cis-enol forms of b-ketoesters and AA compounds
Mater
|
AAa
|
|
MAA
|
|
EAA
|
|
|
EMA
|
|
|
EBAb
|
|
|
BAAc
|
|
AU1-I
|
X-ray
|
AU1-I
|
AU1-I
|
AU2-I
|
AU1-I
|
AU2-I
|
AU1-I
|
AU2-I
|
AU1-I
|
AU2-I
|
d C-C
|
1.444
|
1.412
|
1.446
|
1.447
|
1.447
|
1.459
|
1.459
|
1.444
|
1.444
|
1.446
|
1.446
|
d C=C
|
1.370
|
1.338
|
1.363
|
1.362
|
1.363
|
1.372
|
1.372
|
1.368
|
1.368
|
1.363
|
1.362
|
d C-O
|
1.326
|
1.331
|
1.334
|
1.334
|
1.334
|
1.338
|
1.338
|
1.336
|
1.336
|
1.334
|
1.334
|
d C=O
|
1.246
|
1.238
|
1.234
|
1.234
|
1.234
|
1.236
|
1.236
|
1.236
|
1.236
|
1.235
|
1.234
|
d O-H
|
1.003
|
1.030
|
0.990
|
0.991
|
0.991
|
0.993
|
0.992
|
0.993
|
0.992
|
0.99
|
0.99
|
d O...H
|
1.634
|
|
1.727
|
1.724
|
1.723
|
1.651
|
1.650
|
1.692
|
1.691
|
1.723
|
1.728
|
d O-H + d O...H
|
2.637
|
|
2.718
|
2.715
|
2.714
|
2.644
|
2.642
|
2.685
|
0.699
|
2.713
|
2.718
|
< C-H-O
|
106.2
|
|
107.2
|
107.2
|
107.1
|
107.4
|
107.3
|
107.1
|
107.1
|
107.1
|
107.2
|
< O-H-O
|
148.5
|
|
146.1
|
146.2
|
146.2
|
147.5
|
147.6
|
147.9
|
147.7
|
146.2
|
145.8
|
< C-C=O
|
121.5
|
120.5
|
124.5
|
124.3
|
124.2
|
125.4
|
125.2
|
124.5
|
124.4
|
124.2
|
124.4
|
< C-C=C
|
120.8
|
122.2
|
120.3
|
120.3
|
120.4
|
117.4
|
117.4
|
120.1
|
120.4
|
120.4
|
120.3
|
< C=C-O
|
122.0
|
122.8
|
123.0
|
123.0
|
123.0
|
123.0
|
123.0
|
121.7
|
121.8
|
123.0
|
123.0
|
HO1C2C3
|
-0.035
|
|
-0.004
|
0.001
|
-0.076
|
0.003
|
-0.060
|
-0.006
|
0.110
|
-0.003
|
0.013
|
O2C4C3C2
|
-0.152
|
|
0.002
|
0.005
|
0.082
|
0.020
|
-0.094
|
0.028
|
-0.531
|
0.194
|
-0.005
|
C4O2HO1
|
-0.076
|
|
0.067
|
0.030
|
-0.334
|
0.000
|
-0.064
|
0.053
|
1.632
|
-0.098
|
0.082
|
O2HO1C2
|
0.030
|
|
-0.048
|
-0.022
|
0.338
|
0.006
|
0.091
|
-0.028
|
-1.537
|
0.145
|
-0.074
|
d O…O
|
2.544
|
2.535
|
2.608
|
2.606
|
2.605
|
2.545
|
2.544
|
2.587
|
2.586
|
2.605
|
2.609
|
q1(d c-c -d C=c)
|
0.074
|
0.074
|
0.083
|
0.084
|
0.084
|
0.088
|
0.088
|
0.076
|
0.076
|
0.083
|
0.084
|
q2(d c-o -d c=o)
|
0.080
|
0.093
|
0.100
|
0.100
|
0.100
|
0.102
|
0.102
|
0.100
|
0.100
|
0.099
|
0.100
|
Q =q1+q2
|
0.154
|
0.167
|
0.184
|
0.184
|
0.184
|
0.190
|
0.190
|
0.176
|
0.176
|
0.182
|
0.184
|
λ=(1-Q/0.32)/2
|
0.259
|
0.239
|
0.213
|
0.212
|
0.213
|
0.203
|
0.203
|
0.225
|
0.225
|
0.216
|
0.213
|
r BCP
|
0.0573
|
|
0.0451
|
0.0455
|
0.0455
|
0.0540
|
0.0541
|
0.0490
|
0.0490
|
0.0455
|
0.045
|
Ñr2 BCP
|
-0.0365
|
|
-0.0334
|
-0.0335
|
-0.0337
|
-0.0380
|
-0.0381
|
-0.0350
|
-0.0351
|
-0.0337
|
-0.0334
|
r RCP
|
0.0210
|
|
0.0195
|
0.0196
|
0.0196
|
0.0207
|
0.0207
|
0.0203
|
0.0203
|
0.0196
|
0.0195
|
Ñr2 RCP
|
-0.033
|
|
-0.0297
|
-0.0298
|
-0.0298
|
-0.0319
|
-0.0319
|
-0.0309
|
-0.0309
|
-0.0298
|
-0.0297
|
(kj/mol)EHB d
|
76.0
|
|
54.9
|
55.6
|
55.9
|
71.7
|
71.9
|
61.7
|
61.9
|
54.7
|
54.9
|
a. obtained from Ref.[18]
b. obtained from Ref.[5]
c. obtained from Ref.[4]
d. EIHB, hydrogen bond energy (in kJ mol-1) obtained from AIM by using (B3LYP/ 6-311++G**)
Table 3 The experimental spectroscopic values related to IHB strength of the cis-enol forms and keto forms of b-ketoesters and AA compounds
Enol form
|
AAa
|
MAAb
|
EAAb
|
EMAb
|
EBAc
|
BAAd
|
AU1-I
|
AU1-I
|
AU1-I
|
AU1-I
|
AU1-I
|
AU1-I
|
d OH
|
15.40
|
12.03e
|
12.10e
|
12.60e
|
12.59
|
12.05
|
u CH(CCl4)
|
3090
|
3185
|
-
|
2940
|
3105
|
3114
|
u OH(CCl4)
|
2875
|
3020
|
3010
|
2985
|
3020
|
3050
|
u C=O, u C=C
( d OH )( d CH )
|
1654-1630
|
1654-1630
|
1653-1634
|
1652-1619
|
1650-1625
|
1655-1633
|
g OH(CCl4)
|
957
|
850
|
860
|
860
|
839
|
841
|
D
|
509
|
425
|
450
|
440
|
488
|
497
|
uo…o
|
366
|
338
|
340
|
416
|
316
|
280
|
G
|
140
|
220
|
207
|
319
|
|
220
|
Keto form
|
AAf
|
MAAb
|
EAAb
|
EMAb
|
EBAc
|
BAAd
|
ua CaH2
|
-
|
2958
|
2907
|
2906
|
2967
|
3009
|
us CaH2
|
-
|
2845
|
2873
|
2878
|
2939
|
2931
|
u C=O
|
1727
|
1749
|
1745
|
1745
|
1745
|
1752
|
u C=O
|
1707
|
1723
|
1722
|
-
|
1692
|
1725
|
sic CaH2
|
1434
|
1458
|
1445
|
1477
|
1495
|
1456
|
w CaH2
|
1159
|
1318
|
1312
|
1358
|
1383
|
1314
|
t CaH2
|
1171
|
-
|
-
|
1326
|
1308
|
1266
|
r CaH2
|
970
|
1151
|
1150
|
1154
|
789
|
965
|
a. obtained from Ref.[18]
b. This work
c. obtained from Ref.[5]
d. obtained from Ref.[4]
e. From SDBS Information: https://db.aist.go.jp/sdbs/cgibin/landingpage?sdbsno=7942
f. obtained from Ref.[36]
Table 4 The calculated Wiberg bond orders for average the most stable enol and keto forms for b-ketoester calculated at B3LYP/6-311++G** level.
Bond order
|
AA
|
MAA
|
EAA
|
EMA
|
EBA
|
BAA
|
E1
|
K1
|
E
|
K ave
|
E ave
|
K ave
|
E ave
|
K ave
|
E ave
|
K ave
|
E ave
|
K ave
|
O1-H1
|
0.621
|
|
0.654
|
|
0.653
|
|
0.642
|
|
0.644
|
|
0.654
|
|
O1….H1
|
0.106
|
|
0.071
|
|
0.072
|
|
0.086
|
|
0.080
|
|
0.070
|
|
O1-C2
|
1.165
|
1.825
|
1.131
|
1.840
|
1.130
|
1.839
|
1.124
|
1.836
|
1.121
|
1.784
|
1.131
|
1.838
|
O2=C4
|
1.590
|
1.825
|
1.572
|
1.752
|
1.567
|
1.757
|
1.557
|
1.741
|
1.556
|
1.763
|
1.567
|
1.729
|
C3-C4
|
1.187
|
0.964
|
1.136
|
0.972
|
1.135
|
0.976
|
1.118
|
0.955
|
1.146
|
0.975
|
1.137
|
0.974
|
C3=C2
|
1.555
|
0.964
|
1.604
|
0.969
|
1.605
|
0.971
|
1.574
|
0.939
|
1.564
|
0.973
|
1.602
|
0.965
|
O1….O2
|
0.056
|
|
0.038
|
|
0.038
|
|
0.043
|
|
0.038
|
|
0.040
|
|
Table 5 Selected natural atomic charges (e) for average the most stable enol and keto foems for b-ketoesters with AA.
Atomic Charges
|
AA
|
MAA
|
EAA
|
EMA
|
EBA
|
BAA
|
E1
|
K1
|
E
|
K ave
|
E ave
|
K ave
|
E ave
|
K ave
|
E ave
|
K ave
|
E ave
|
K ave
|
H1
|
0.505
|
|
0.508
|
0.244
|
0.508
|
|
0.506
|
|
0.510
|
|
0.508
|
|
O1
|
-0.666
|
-0.550
|
-0.673
|
-0.539
|
-0.674
|
-0.540
|
-0.680
|
-0.545
|
-0.673
|
-0.545
|
-0.673
|
-0.541
|
O2
|
-0.644
|
-0.550
|
-0.678
|
-0.598
|
-0.681
|
-0.597
|
-0.680
|
-0.606
|
-0.681
|
-0.592
|
-0.681
|
-0.615
|
O3
|
|
|
-0.540
|
-0.547
|
-0.552
|
-0.561
|
-0.556
|
-0.563
|
-0.551
|
-0.565
|
-0.546
|
-0.541
|
C1
|
-0.626
|
-0.674
|
-0.623
|
-0.675
|
-0.623
|
-0.670
|
-0.623
|
-0.675
|
-0.113
|
-0.154
|
-0.623
|
-0.679
|
C2
|
0.464
|
0.587
|
0.445
|
0.590
|
0.444
|
0.591
|
0.440
|
0.597
|
0.431
|
0.576
|
0.446
|
0.590
|
C3
|
-0.462
|
-0.563
|
-0.460
|
-0.564
|
-0.459
|
-0.567
|
-0.272
|
-0.385
|
-0.433
|
-0.563
|
-0.458
|
-0.560
|
C4
|
0.527
|
0.587
|
0.778
|
0.819
|
0.781
|
0.823
|
0.794
|
0.825
|
0.778
|
0.829
|
0.784
|
0.822
|
Ha
|
0.215
|
|
0.229
|
|
0.228
|
|
|
|
0.226
|
|
0.197
|
|
Table 6 Relevant second order perturbation energies E(2) (donor–acceptor) interactions of kcal.mol-1 in the most stable enol and keto forms of b-ketoester and AA compounds.
Donor NBO (i)
|
Acceptor NBO (j)
|
AA
|
|
MAA
|
|
EAA
|
|
EMA
|
|
EBA
|
|
BAA
|
|
AU1-I
|
K1
|
AU1-I
|
K1
|
AU1-I
|
K1
|
AU1-I
|
K1
|
AU1-I
|
K1
|
AU2-I
|
K1
|
п
|
C2-C3
|
п*
|
C4-O2
|
31.97
|
|
29.22
|
|
28.97
|
|
29.72
|
|
29.56
|
|
29.12
|
|
CR ( 1)
|
O1
|
RY*( 1)
|
C2
|
3.64
|
7.39
|
3.44
|
7.36
|
3.43
|
7.36
|
3.39
|
7.44
|
3.02
|
6.64
|
3.43
|
7.29
|
CR ( 1)
|
O2
|
RY*( 1)
|
C4
|
6.12
|
|
6.08
|
|
5.98
|
|
5.81
|
|
5.96
|
|
5.93
|
|
LP ( 2)
|
O1
|
п*
|
C2-C3
|
48.5
|
|
44.94
|
|
44.86
|
|
42.38
|
|
43.26
|
|
44.8
|
|
LP ( 1)
|
O2
|
σ*
|
C4-C3
|
7.87
|
|
3.62
|
|
3.69
|
|
3.86
|
|
3.85
|
|
3.64
|
|
LP ( 2)
|
O2
|
σ*
|
O1-H1
|
27.67
|
|
16.81
|
|
17.15
|
|
22.11
|
|
19.45
|
|
16.78
|
|
LP ( 1)
|
O1
|
σ*
|
C2-C3
|
6.68
|
1.70
|
6.70
|
1.73
|
6.69
|
1.73
|
6.16
|
1.63
|
6.22
|
1.4
|
6.69
|
1.59
|
LP ( 2)
|
O1
|
σ*
|
C2-C3
|
|
21.67
|
|
23.13
|
|
22.99
|
|
22.27
|
|
22.52
|
|
21.77
|
LP ( 2)
|
O1
|
σ*
|
C2-C1
|
|
19.41
|
|
20.13
|
|
20.18
|
|
19.74
|
|
18.95
|
|
19.27
|
LP ( 1)
|
O2
|
RY*( 1)
|
C4
|
12.86
|
17.58
|
13.6
|
17.31
|
13.25
|
17.41
|
12.31
|
17.61
|
12.95
|
16.95
|
13.26
|
17.47
|
σ
|
O1-H1
|
σ*
|
C1-C2
|
5.51
|
|
5.12
|
|
5.12
|
|
4.72
|
|
4.96
|
|
5.11
|
|
LP ( 2)
|
O2
|
σ*
|
O3-C4
|
|
|
28.69
|
32.5
|
28.16
|
31.98
|
27.73
|
32.61
|
27.86
|
32.09
|
28.16
|
31.05
|
LP ( 2)
|
O2
|
σ*
|
C4-C3
|
10
|
21.67
|
11.54
|
18.46
|
11.44
|
18.45
|
10.65
|
19.45
|
11.08
|
18.52
|
11.5
|
18.59
|
П*
|
C4-O2
|
П*
|
C3-C2
|
111.93
|
|
67.88
|
|
68.68
|
|
51.37
|
|
76.72
|
|
67.66
|
|
LP ( 1)
|
O3
|
σ*
|
C4-O2
|
|
|
7.66
|
7.59
|
7.65
|
7.99
|
7.19
|
7.9
|
7.65
|
7.6
|
7.63
|
7.87
|
LP ( 2)
|
O3
|
П*
|
C4-O2
|
|
|
47.31
|
47.56
|
47.77
|
48.17
|
47.54
|
45.95
|
47.54
|
47.83
|
47.61
|
46.59
|
Table 7 The experimental and B3LYP/6-311++G** calculated, wavelength (l), oscillator strengths (f), and major contributions for stable keto and cis-enol forms of b-ketoester compounds.
|
lmax
|
¦
|
Major contribution a
|
lmax(Abs) Exp.b
|
Equlibrium Keq c
|
|
Kcal
|
% enol cal
|
kexp
|
% enolexp
|
AA
|
AU1
|
250
|
0.366
|
H®L (98%)
|
|
|
|
|
|
AU1CH3CN
|
250
|
0.366
|
H®L (98%)
|
248(0.460)
|
3.85
|
20.6
|
0.95
|
51
|
AU1C2H5OH
|
250
|
0.367
|
H®L (98%)
|
265(0.275)
|
3.87
|
20.5
|
0.86
|
53
|
AU1CCl4
|
250
|
0.370
|
H®L (98%)
|
304 (0.330)
|
3.28
|
23.4
|
0.60
|
62
|
K1
|
201
|
0.128
|
H®L+2 (66%)
|
|
|
|
|
|
K1 CH3CN
|
205
|
0.095
|
H-1®L+2 (84%)
|
191(0.485)
|
|
|
|
|
K1C2H5OH
|
205
|
0.095
|
H-1®L+2 (84%)
|
194(0.318)
|
|
|
|
|
K1CCl4
|
199
|
0.113
|
H®L+2 (89%)
|
196(0.548)
|
|
|
|
|
MAA
|
AU1-I
|
228
|
0.401
|
H®L (98%)
|
|
|
|
|
|
AU1-I CH3CN
|
233
|
0.469
|
H®L 98%)
|
243(0.761)
|
4.69
|
17.6
|
4.76
|
17
|
AU1-I C2H5OH
|
233
|
0.471
|
H®L (98%)
|
244(0.592)
|
4.64
|
17.7
|
1.49
|
40
|
AU1-I CCl4
|
234
|
0.477
|
H®L (98%)
|
261(0.674)
|
5.57
|
15.2
|
4.01
|
20
|
K1
|
198
|
0.048
|
H-1®L +2(49%)
|
|
|
|
|
|
K1 CH3CN
|
186
|
0.1
|
H-1®L +2(55%)
|
191(0.16)
|
|
|
|
|
K1 C2H5OH
|
186
|
0.102
|
H-1®L +2(55%)
|
198 (0.396)
|
|
|
|
|
K1 CCl4
|
189
|
0.085
|
H-1®L +1(35%)
|
199(0.168)
|
|
|
|
|
EAA
|
AU1-I
|
222
|
0.469
|
H→L(96%)
|
|
|
|
|
|
AU1-I CH3CN
|
233
|
0.495
|
H→L(98%)
|
243(0.637)
|
8.48
|
10.5
|
0.70
|
59
|
AU1-I C2H5OH
|
234
|
0.497
|
H®L(98%)
|
245(0.757)
|
8.42
|
10.6
|
1.47
|
40
|
AU1-I CCl4
|
234
|
0.502
|
H→L(98%)
|
260(0.440)
|
6.65
|
13.1
|
2.02
|
33
|
K1
|
197
|
0.076
|
H→L+2(76%)
|
|
|
|
|
|
K1 CH3CN
|
190
|
0.058
|
H→L+2(94%)
|
193(0.912)
|
|
|
|
|
K1C2H5OH
|
190
|
0.059
|
H→L+2(94%)
|
198(0.514)
|
|
|
|
|
K1 CCl4
|
195
|
0.075
|
H→L+2(85%)
|
205 (0.218)
|
|
|
|
|
EMA
|
|
|
|
|
|
|
|
|
AU1-I
|
242
|
0.348
|
H→L(98%)
|
|
|
|
|
|
AU1-I CH3CN
|
247
|
0.407
|
H→L(98%)
|
216 (0.742)
|
8.58
|
10.4
|
1.00
|
50
|
AU1-I C2H5OH
|
247
|
0.408
|
H→L(98%)
|
258 (1.848)
|
8.56
|
10.5
|
2.17
|
32
|
AU1-I CCl4
|
248
|
0.416
|
H→L(98%)
|
261(0.903)
|
7.36
|
11.9
|
1.83
|
35
|
K1
|
185
|
0.056
|
H-2→L(33%)
|
|
|
|
|
|
K1 CH3CN
|
190
|
0.047
|
H-1→L+1(57%)
|
197(0.742)
|
|
|
|
|
K1 C2H5OH
|
191
|
0.048
|
H-1→L+1(56%)
|
193 (0.858)
|
|
|
|
|
K1 CCl4
|
187
|
0.056
|
H-1→L(80%)
|
215 (0.493)
|
|
|
|
|
EBA
|
|
|
|
|
|
|
|
|
AU1-I
|
287
|
0.575
|
H→L(99%)
|
|
|
|
|
|
AU1-I CH3CN
|
230
|
0.143
|
H→L(99%)
|
244(0.431)
|
1.12
|
47.2
|
0.58
|
63
|
AU1-I C2H5OH
|
231
|
0.118
|
H→L(99%)
|
244(0.751)
|
0.91
|
52.3
|
0.66
|
60
|
AU1-I CCl4
|
232
|
0.145
|
H→L(99%)
|
255(0.442)
|
0.91
|
52.2
|
0.75
|
57
|
K1
|
201
|
0.108
|
H-2→L(40%)
|
|
|
|
|
|
K1 CH3CN
|
203
|
0.128
|
H-1→L(77%)
|
199(0.738)
|
|
|
|
|
K1 C2H5OH
|
203
|
0.130
|
H-1→L(74%)
|
203(1.153)
|
|
|
|
|
K1 CCl4
|
203
|
0.158
|
H-2→L(47%)
|
204(0.586)
|
|
|
|
|
BAA
|
|
|
|
|
|
|
|
|
AU1-I
|
231
|
0.542
|
H→L(95%)
|
|
|
|
|
|
AU1-I CH3CN
|
235
|
0.624
|
H→L(96%)
|
|
|
|
|
|
AU1-I C2H5OH
|
235
|
0.626
|
H→L(96%)
|
|
|
|
|
|
AU1-I CCl4
|
236
|
0.632
|
H→L(96%)
|
260(0.577)
|
5.23
|
16.0
|
4.51
|
18
|
K1
|
211
|
0.085
|
H-1→L+1(42%)
|
|
|
|
|
|
K1 CH3CN
|
213
|
0.035
|
H→L+1(44%)
|
194(1.081)
|
|
|
|
|
K1 C2H5OH
|
213
|
0.039
|
H→L+1(44%)
|
|
|
|
|
|
K1 CCl4
|
200
|
0.121
|
H-2→L+3(40%)
|
212(0.128)
|
|
|
|
|
a The calculated and experimental UV-Vis spectra are in n-hexane. H-n means n levels lower than HOMO, and L - n means n levels upper than LUMO.
b This work in Keq=Enol/Keto
c experimental UV/visible absorption spectra