and 2.182–2.190/DF+, 2.184–2.199/HF when (engaging the same acceptor)
H25⋯O17 is also present. Its red shift for the vibrational frequency of O16–H23
implies a decrease from 3,619–3,623, when it is free, to 3,562–3,568; this decrease
Table 7 HOMO-LUMO energy difference for the conformers of muchimangin B
Conformer
HOMO-LUMO energy difference (kcal/mol)
In vacuo
In solution/DF+
HF
DF+
In chloroform
In acetonitrile
In water
1-a
225.0
83.1
81.8
81.8
83.7
1-b
222.5
81.0
80.9
81.4
82.6
1-c
226.4
84.1
83.4
83.5
84.2
1-d
226.2
84.0
83.4
83.7
84.3
1-e
227.3
85.0
83.7
83.5
84.3
1-f
225.1
82.2
81.4
81.5
82.1
2-a
234.7
90.3
88.8
87.9
87.8
1-g
227.6
85.1
82.3
82.3
83.2
1-h
229.9
82.8
82.3
82.3
83.2
1-i
222.6
80.8
−
a
79.6
81.2
2-b
232.6
89.5
87.3
86.2
86.1
3-a
226.8
84.3
82.4
82.2
84.0
3-b
225.0
83.9
81.8
81.7
82.5
3-c
227.9
85.2
83.7
83.6
84.4
4
240.2
95.0
92.7
91.5
90.6
5-a
231.6
87.9
86.3
86.0
87.2
5-b
228.9
85.9
85.4
85.5
85.4
6-b
231.1
87.6
85.4
85.5
86.1
6-a
233.8
90.3
87.3
86.6
87.6
5-c
232.1
88.1
87.6
87.4
87.5
6-c
235.3
91.4
88.9
88.2
88.1
7
240.5
94.5
92.9
91.7
90.8
8
237.5
92.3
91.1
90.0
89.5
9-a
235.6
91.6
88.0
86.9
88.0
9-b
235.4
90.8
87.4
86.7
86.5
9-c
236.7
92.3
89.3
88.3
88.3
10
249.2
102.6
99.6
97.9
96.5
11-a
241.1
96.9
93.4
92.2
92.5
11-b
239.1
94.4
92.3
91.7
91.2
11-c
242.3
97.5
94.7
93.6
92.8
The results in vacuo are from full optimization HF/6-31G(d,p) calculations and DFT/B3LYP/6-31
+G(d,p) calculations (respectively denoted as HF and DF+ in the column headings). The results in
solution are from PCM DFT/B3LYP/6-31+G(d,p) single point calculations on the in-vacuooptimised DFT/B3LYP/6-31+G(d,p) results
a The calculation in chloroform solution does not converge for this conformer
Ab-Initio and DFT Study of the Muchimangin-B Molecule
105
H25⋯O17 is also present. Its red shift for the vibrational frequency of O16–H23
implies a decrease from 3,619–3,623, when it is free, to 3,562–3,568; this decrease
Table 7 HOMO-LUMO energy difference for the conformers of muchimangin B
Conformer
HOMO-LUMO energy difference (kcal/mol)
In vacuo
In solution/DF+
HF
DF+
In chloroform
In acetonitrile
In water
1-a
225.0
83.1
81.8
81.8
83.7
1-b
222.5
81.0
80.9
81.4
82.6
1-c
226.4
84.1
83.4
83.5
84.2
1-d
226.2
84.0
83.4
83.7
84.3
1-e
227.3
85.0
83.7
83.5
84.3
1-f
225.1
82.2
81.4
81.5
82.1
2-a
234.7
90.3
88.8
87.9
87.8
1-g
227.6
85.1
82.3
82.3
83.2
1-h
229.9
82.8
82.3
82.3
83.2
1-i
222.6
80.8
−
a
79.6
81.2
2-b
232.6
89.5
87.3
86.2
86.1
3-a
226.8
84.3
82.4
82.2
84.0
3-b
225.0
83.9
81.8
81.7
82.5
3-c
227.9
85.2
83.7
83.6
84.4
4
240.2
95.0
92.7
91.5
90.6
5-a
231.6
87.9
86.3
86.0
87.2
5-b
228.9
85.9
85.4
85.5
85.4
6-b
231.1
87.6
85.4
85.5
86.1
6-a
233.8
90.3
87.3
86.6
87.6
5-c
232.1
88.1
87.6
87.4
87.5
6-c
235.3
91.4
88.9
88.2
88.1
7
240.5
94.5
92.9
91.7
90.8
8
237.5
92.3
91.1
90.0
89.5
9-a
235.6
91.6
88.0
86.9
88.0
9-b
235.4
90.8
87.4
86.7
86.5
9-c
236.7
92.3
89.3
88.3
88.3
10
249.2
102.6
99.6
97.9
96.5
11-a
241.1
96.9
93.4
92.2
92.5
11-b
239.1
94.4
92.3
91.7
91.2
11-c
242.3
97.5
94.7
93.6
92.8
The results in vacuo are from full optimization HF/6-31G(d,p) calculations and DFT/B3LYP/6-31
+G(d,p) calculations (respectively denoted as HF and DF+ in the column headings). The results in
solution are from PCM DFT/B3LYP/6-31+G(d,p) single point calculations on the in-vacuooptimised DFT/B3LYP/6-31+G(d,p) results
a The calculation in chloroform solution does not converge for this conformer
Ab-Initio and DFT Study of the Muchimangin-B Molecule
105