Ab Initio and DFT Computational Study …
215
Table 2 Relative energies of the lower energy conformers of the model structure. HF/6-31G(d,p)
and DFT/B3LYP/6-31+G(d,p) results in vacuo, respectively denoted as HF and DFT in the
column headings. The absolute energies of the lowest-energy conformer is −1445.7499595 and
−1454.4781847 hartree in the HF and DFT results respectively
Conformers
Relative energy
(kcal/mol)
Conformers
Relative energy
(kcal/mol)
HF
DFT
HF
DFT
d-r-η-p-a-e-j
0.000
0.000
s-r-ε-q-a-e-k
5.016
4.502
d-r-η-p-a-e-k
0.013
0.015
s-r-ε-q-a-e-j
5.141
4.621
d-r-η-p-a-f-j
0.423
0.209
d-w-p-b-e-k
5.149
5.668
d-r-η-p-a-f-k
0.494
0.265
d-w-q-b-f-k
5.210
5.413
d-r-η-p-b-e-k
1.003
1.424
s-r-η-p-a-e-k
5.214
4.647
d-r-η-p-b-e-j
1.007
1.457
d-w-q-b-e-j
5.216
6.119
s-w-ε-q-a-e-k
1.140
1.345
d-w-q-a-e-j
5.216
5.453
s-w-ε-q-a-e-j
1.188
1.397
d-r-η-u-p-a-f-j
5.266
3.586
d-r-η-p-b-f-j
1.209
1.507
d-w-q-a-e-k
5.293
5.514
d-r-η-p-b-f-k
1.243
1.480
d-r-η-u-p-a-f-k
5.334
3.630
s-w-ε-q-b-e-j
1.486
2.295
s-r-η-p-a-e-j
5.349
4.787
s-w-ε-q-a-f-j
1.619
1.612
s-r-η-p-b-f-k
5.372
4.919
s-w-ε-q-a-f-k
1.633
1.601
d-w-q-b-f-j
5.469
5.956
s-w-ε-q-b-f-k
1.962
2.428
s-r-ε-q-a-f-k
5.484
4.734
d-w-p-a-e-k
4.463
4.786
d-w-q-b-e-k
5.543
6.119
d-w-p-a-f-j
4.663
4.804
s-r-ε-q-a-f-j
5.545
4.812
s-r-ε-q-b-e-j
4.693
4.656
s-w-p-b-f-j
5.566
5.634
s-r-ε-q-b-f-j
4.815
4.530
s-r-η-p-a-f-k
5.672
4.881
d-r-η-u-p-a-e-j
4.848
3.376
d-r-q-b-e-k
5.722
5.720
d-r-q-a-e-j
4.848
4.751
d-r-q-b-e-j
5.741
5.750
d-w-p-a-f-k
4.857
4.995
d-r-q-a-e-k
5.745
5.470
d-r-η-u-p-a-e-k
4.857
3.379
s-r-η-p-a-f-j
5.745
4.979
d-w-p-b-e-j
4.928
5.476
d-w-p-b-f-k
5.876
5.754
d-r-q-b-f-k
4.981
4.950
d-w-q-a-f-k
5.827
5.869
d-r-q-b-f-j
4.981
4.950
d-w-q-a-f-j
5.689
5.764
p conformers when the O8–H15···π interaction between H15 and ring B is present,
whereas they have higher energy than the p conformers when the interaction is absent.
No consistent conformational preference patterns are identified for the a/b, e/f and
j/k pairs of conformers.
Since the properties of MODL may serve as comparison references for the other
molecules, they are reported in the ESI: parameters of the first IHB (Table S2),
distance between the H atom and the closest C atom in the acceptor B aromatic ring
for the O–H···π IHBs (Table S3), dipole moment (Table S4), and HOMO-LUMO
215
Table 2 Relative energies of the lower energy conformers of the model structure. HF/6-31G(d,p)
and DFT/B3LYP/6-31+G(d,p) results in vacuo, respectively denoted as HF and DFT in the
column headings. The absolute energies of the lowest-energy conformer is −1445.7499595 and
−1454.4781847 hartree in the HF and DFT results respectively
Conformers
Relative energy
(kcal/mol)
Conformers
Relative energy
(kcal/mol)
HF
DFT
HF
DFT
d-r-η-p-a-e-j
0.000
0.000
s-r-ε-q-a-e-k
5.016
4.502
d-r-η-p-a-e-k
0.013
0.015
s-r-ε-q-a-e-j
5.141
4.621
d-r-η-p-a-f-j
0.423
0.209
d-w-p-b-e-k
5.149
5.668
d-r-η-p-a-f-k
0.494
0.265
d-w-q-b-f-k
5.210
5.413
d-r-η-p-b-e-k
1.003
1.424
s-r-η-p-a-e-k
5.214
4.647
d-r-η-p-b-e-j
1.007
1.457
d-w-q-b-e-j
5.216
6.119
s-w-ε-q-a-e-k
1.140
1.345
d-w-q-a-e-j
5.216
5.453
s-w-ε-q-a-e-j
1.188
1.397
d-r-η-u-p-a-f-j
5.266
3.586
d-r-η-p-b-f-j
1.209
1.507
d-w-q-a-e-k
5.293
5.514
d-r-η-p-b-f-k
1.243
1.480
d-r-η-u-p-a-f-k
5.334
3.630
s-w-ε-q-b-e-j
1.486
2.295
s-r-η-p-a-e-j
5.349
4.787
s-w-ε-q-a-f-j
1.619
1.612
s-r-η-p-b-f-k
5.372
4.919
s-w-ε-q-a-f-k
1.633
1.601
d-w-q-b-f-j
5.469
5.956
s-w-ε-q-b-f-k
1.962
2.428
s-r-ε-q-a-f-k
5.484
4.734
d-w-p-a-e-k
4.463
4.786
d-w-q-b-e-k
5.543
6.119
d-w-p-a-f-j
4.663
4.804
s-r-ε-q-a-f-j
5.545
4.812
s-r-ε-q-b-e-j
4.693
4.656
s-w-p-b-f-j
5.566
5.634
s-r-ε-q-b-f-j
4.815
4.530
s-r-η-p-a-f-k
5.672
4.881
d-r-η-u-p-a-e-j
4.848
3.376
d-r-q-b-e-k
5.722
5.720
d-r-q-a-e-j
4.848
4.751
d-r-q-b-e-j
5.741
5.750
d-w-p-a-f-k
4.857
4.995
d-r-q-a-e-k
5.745
5.470
d-r-η-u-p-a-e-k
4.857
3.379
s-r-η-p-a-f-j
5.745
4.979
d-w-p-b-e-j
4.928
5.476
d-w-p-b-f-k
5.876
5.754
d-r-q-b-f-k
4.981
4.950
d-w-q-a-f-k
5.827
5.869
d-r-q-b-f-j
4.981
4.950
d-w-q-a-f-j
5.689
5.764
p conformers when the O8–H15···π interaction between H15 and ring B is present,
whereas they have higher energy than the p conformers when the interaction is absent.
No consistent conformational preference patterns are identified for the a/b, e/f and
j/k pairs of conformers.
Since the properties of MODL may serve as comparison references for the other
molecules, they are reported in the ESI: parameters of the first IHB (Table S2),
distance between the H atom and the closest C atom in the acceptor B aromatic ring
for the O–H···π IHBs (Table S3), dipole moment (Table S4), and HOMO-LUMO