clar structure in inorganic bn analogues of polybenzenoid hydrocarbons: exist or not? speaker:...
TRANSCRIPT
Clar Structure in Inorganic BN Analogues of Polybenzenoid Hydrocarbons: Exist or Not?
Speaker: Jingjing Wu
Advisor: Jun Zhu
2014/4/11
1
Main contents
• Introduction
• Computational method
• Results and discussion
• Conclusion
• Questions
2
Introduction Clar structure was proposed by Eric Clar in the 1950s according to the
experimental observations. Since then, Clar structure have attracted
increasing interest from both experimentalists and theoreticians.
Clar, E.; Kelly, W. Journal of the American Chemical Society 1954, 76, 3502.Clar, E.; McCallum, A. Tetrahedron 1960, 10, 171. 3
dark green
1
blue greenp = 6510
2 3
violet red = 5385= 3430
4
red = 5230= 3470
5
yellow = 4250 = 4000 = 3280
6
colourless = 3820 = 3335 = 2950
Figure 1. All wavelengths(Å) were measured in benzene expect 2 and the significance of benzenoid rings for the stability of aromatic hydrocarbons in color change.
27.2 D2h
1 2
16.7 Cs
Figure 2. Clar structural representations of heptabenzene isomers, symmetries and relative Gibbs free energies (kcal/mol) compare with 6.
3
10.8 C2h
4
7.1 C2v
5
2.4 Cs
6
0.0 D2h
Zhu, J.; Dahlstrand, C.; Smith, J. R.; Villaume, S.; Ottosson, H. Symmetry 2010, 2, 1653.
Introduction
4
Computational methods
Package: Gaussian 03
DFT method: B3LYP
Basis set: 6-311G**
5
Results and discussion
HB
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
NH
BH
HN
4.9 C2v
0.6
832
0 .3
979
0 .3 6
2 9
0 .3 6
2 9
0.3727 0.3253 0.3170 0.322971B
HN
BH
N
B
N
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
NH
BH
HN
BH
HN
HB
HN
3.0 Cs
0.6
7 09
0.7
64
0
0. 4
17
3
0.47
44
0.3
705
0.3
629
0.3
738
0.6
85
9
0. 4
01
0
0.3256
0.3948 0.3243 0.3261 0.3245 0.3208 0.367072
B
N
B
N
B
N
BH
N
B
HN
BH
N
B
HN
BH
HN
HB
HN
HB
HN
BH
NH
BH
N
B
HN
BH
NH
BH
HN
1.5 Cs
0.6600 0.7720
0.6
64
3
0.45750.5512
0.7
76
5
0.4
0 96
0.6480
0.7
8 73
0.6683 0.7726
0. 5
637
0.3965
0 .4 3
26
0.3840
0.4490 0.7012 0.6994
0.37
94
0.52930.5584
0.6773 0.6966
0.3
775
0.5121 0.5161
0.6834 0.6901
0.5240 0.5138 0.5021
0.40
88
0.6405 0.7715
0.6
958
0.7467
0.3190
0.0735
0.3383
0.3218 0.3191 0.3126 0.3627731
HB
N
B
N
B
HN
BH
N
B
HN
BH
N
B
HN
HB
HN
BH
NH
BH
N
B
HN
BH
NH
B
N NH
BH
HN
HB
1.9 Cs
0 .5 5
76
0 .77
71
0.40
30
0 .6
0 20
0.36
90
0 .3
690
0.4
149
0.75
70
0 .4 7
51
0 .6 6
94
0.3202
0.3807 0.3410 0.3190 0.3200 0.3846
0.3234
732
B
N
B
N
B
N
BH
N
B
HN
BH
N
B
HN
BH
HN
HB
HN
HB
HN
BH
NH
B
N
BH
HN
HN
BH
NH
BH
0.6 Cs
0.6680 0.7780
0.6
54 4
0.37900.
4284
0.3851
0.46600.6525
0.3
920
0.5300
0.78
07
0.6630 0.7697
0.5
573
0.7
72 5
0.4769 0.5712 0.5294 0.5149
0.3
694
0.68500.70890.6711 0.3920
0.4
028
0.51900.7828
0.6
184
0.6341
0.78
22
0.68320.7555
0.5
631
0.3930
0.4899
0.4574
0.3011
0.0979
0.3147
0.3395 0.3017 0.3898
0.3248
74B
N
B
N
B
N
BH
N
B
HN
B
N
B
N
BH
HN
HB
HN
HB
HN
BH
NH
BH
NH
NH
BH
HN
HB
HN
BH
0.0 C2v
0.65
39
0 .76
32
0 .3 8
1 3
0.76
90
0 .5 4
2 6
0.4 2
26
0.3064
0.0903
0.2974
0.281675
Figure 3. ELFπ bifurcation values [BV (ELFπ)] of B-N bonds, the BV (ELFπ) ranges of each ring (in ring) [ΔBV (ELFπ)], the relative Gibbs free energies (kcal mol -1), symmetries at B3LYP/6-311G** level. π-Bonds with BV(ELFπ)’s about in either of the three intervals BV(ELFπ)’s < 0.64, 0.64 ≤ BV(ELFπ) < 0.91, 0.91≤ BV(ELFπ), are denoted as single, π, and double bonds, respectively.
6
Table 1. Six-center Index and NICS(ppm) (NICS (1) and NICS (0) indicate 1 Å above the plane and in the plane of ring, respectively) Indices Calculated for the Different Rings
Indices
Molecule Symmetry Ring SCI NICS(1)/NICS(0)
C2v
1234
0.013450.008650.008180.00815
-1.9/-0.9-1.5/-0.5-1.4/-0.4-1.4/-0.3
Cs
1234567
0.015240.008070.009050.008100.008120.008500.01358
-2.1/-1.2-1.3/-0.2-1.4/-0.3-1.3/-0.3-1.4/-0.3-1.5/-0.5-1.9/-0.9
HB
HNBH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
NH
BH
HN
71 1 2 3 4
B
HNBH
N
BN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
NH
BH
HN
BH
HN
HB
HN
72
1
2 3 4 5 6 7
7
Cs
1234567
0.015310.005030.015330.009330.008060.008570.01341
-2.0/-0.9-0.9/0.4-2.0/-0.9-1.4/-0.3-1.3/-0.2-1.5/-0.4-1.8/-0.8
Cs
1234567
0.014840.008290.008870.008130.009170.008030.01496
-2.1/-1.0-1.3/-0.2-1.5/-0.5-1.3/-0.3-1.4/-0.3-1.3/-0.1-2.1/-1.2
B
NB
N
BN
BH
N
B
HN
BH
N
B
HN
BH
HN
HB
HN
HB
HNBH
NH
BH
N
B
HN
BH
NH
BH
HN
731
1
2
3
4 5 6 7
HB
NB
N
B
HN
BH
N
B
HN
BH
N
B
HN
HB
HNBH
NH
BH
N
B
HN
BH
NH
BN NH
BH
HN
HB
732
1
2 3 4 5 6
7
Results and discussion
8
Cs
1234567
0.015850.004790.015870.009600.008900.008220.01466
-2.0/-0.9-0.9/0.4-2.0/-1.0-1.4/-0.3-1.5/-0.5-1.3/-0.2-2.1/-1.0
C2v
1234
0.015340.004980.015420.01090
-1.9/-0.9-0.8/0.5-1.9/-0.9-1..4/-0.3
D6h
1
0.07745
-11.1/-8.9
C2v
1
0.00000
B
NB
N
BN
BH
N
B
HN
BH
N
B
HN
BH
HN
HB
HN
HB
HNBH
NH
BN
BH
HN
HNBH
NH
BH
74
1
2
3
4 5 6
7
B
NB
N
BN
BH
N
B
HN
BN
BN
BH
HN
HB
HN
HB
HNBH
NH
BH
NH
NH
BH
HN
HB
HNBH
75
1
2
3
4
1
1
9
HB
HNBH
N
B
HN
BH
N
B
HN
BH
NH
BH
HN
1.4
31
C2v0.0
32
Cs
HB
HNB
N
BH
HN
HNBH
N
B
BH
NH
BH
HN
HB
HNBH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
NH
BH
HN
1.6
41
C2v
42
HB
HNB
N
BH
HN
HNBH
N
B
BH
N
B
HN
BH
NH
BH
HN
-0.1 Cs
BHN
HB
HN BH
N B
N
BN
HN BH
NH
BH
NH
BHHN
HB
0.0
43
C3h
HB
HNBH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
NH
BH
HN
2.8
51
C2v
B
HNBH
N
BN
BH
N
B
HN
BH
N
B
HN
BH
NH
BH
HN
BH
HN
HB
HN
1.2
52
Cs
B
NB
N
BN
BH
N
B
HN
BH
NH
BH
HN
BH
HN
HB
HN
HB
HNBH
NH
0.1
531
Cs
N
HBNH
B
NB
NH
B
N
HB
NB
NH
HB
HBNH
BH
NH
NH
HB
HN
HB
0.0 Cs
532
HB
HNBH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
NH
BH
HN
4.0
61
C2v
B
HNBH
N
BN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
HN
HB
HN
BH
NH
BH
HN
2.1
62
Cs
B
NB
N
BN
BH
N
B
HN
BH
N
B
HN
BH
HN
HB
HN
HB
HNBH
NH
BH
NH
BH
HN
1.0
631
Cs
HB
NB
N
B
HN
BH
N
B
HN
BH
N
B
HN
HB
HNBH
NH
BH
NH
BN NH
BH
HN
HB
1.1
632
Cs
N
BN
B
NB
NH
B
N
HB
NH
BH
NB
NH
HB
HN
HB
HN
HBNH
BH
BH
NH
HB
HN
0.0 Cs
64
Results and discussion
10
HB
HNBH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
NH
BH
HN
4.9
71
C2v
B
HNBH
N
BN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
NH
BH
HN
BH
HN
HB
HN
3.0
72
Cs
B
NB
N
BN
BH
N
B
HN
BH
N
B
HN
BH
HN
HB
HN
HB
HNBH
NH
BH
N
B
HN
BH
NH
BH
HN
1.5
731
Cs
HB
NB
N
B
HN
BH
N
B
HN
BH
N
B
HN
HB
HNBH
NH
BH
N
B
HN
BH
NH
BN NH
BH
HN
HB
1.9
732
Cs
B
NB
N
BN
BH
N
B
HN
BH
N
B
HN
BH
HN
HB
HN
HB
HNBH
NH
BN
BH
HN
HNBH
NH
BH
0.6
74
Cs
B
NB
N
BN
BH
N
B
HN
BN
BN
BH
HN
HB
HN
HB
HNBH
NH
BH
NH
NH
BH
HN
HB
HNBH
0.0
75
C2v
B
NBH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
NH
BH
HN
HN
B
NBH
HN
HB
HNBH
5.3
81
C2v
B
HNBH
N
BN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
NH
BH
HN
BH
HN
HB
HN
3.0
82
Cs
B
NB
N
BN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
NH
BH
HN
BH
HN
HB
HN
HB
HNBH
NH
2.4
831
Cs
HB
NB
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
NH
BN
HB
HNBH
NH
NH
BH
HN
HB
2.3
832
Cs
B
NB
N
BN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BN
BH
HN
BH
HN
HB
HN
HB
HNBH
NH HNBH
NH
BH
0.8
84
Cs
B
NB
N
BN
BH
N
B
HN
BH
N
B
HN
BN
BN
BH
HN
HB
HN
HB
HNBH
NH
NH
BH
HN
HB
HNBH
NH
BH
0.4
851
C2v
B
NB
N
BN
BH
N
B
HN
BN
BN
BH
HN
HB
HN
HB
HNBH
NH
BH
NH
N
BH
HN
HB
HNB
HNBH
NH
BH
0.0
852
Cs 11
HB
HNBH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
NH
BH
HN
6.2
91
C2v
B
HNBH
N
BN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
HN
HB
HN
BH
NH
BH
HN
3.9
92
Cs
B
NB
N
BN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
NH
BH
HN
BH
HN
HB
HN
HB
HNBH
NH
3.3
931
Cs
HB
NB
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
NH
BN
HB
HNBH
NH
NH
BH
HN
HB
3.1
932
Cs
B
NB
N
BN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BN
BH
HN
BH
HN
HB
HN
HB
HNBH
NH HNBH
NH
BH
1.4
94
C1
B
NB
N
BN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
HN
HB
HN
HB
HNBH
NH
BN
BN NH
BH
HN
HB
HNBH
NH
BH
1.0
95
C2v
B
NB
N
BN
BH
N
B
HN
BN
BN
BH
HN
HB
HN
HB
HNBH
NH
BH
NH
N
BH
HN
HB
HNB
HNBH
N
B
BH
NH
BH
HN
0.0
96
C1
HB
HNBH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
NH
BH
HN
6.5
101
C2v
B
HNBH
N
BN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
HN
HB
HN
BH
N
B
HN
BH
NH
BH
HN
4.4
102
Cs
B
NB
N
BN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
HN
HB
HN
HB
HNBH
NH
BH
NH
BH
HN
2.2
1031
Cs
HB
NB
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
HB
HNBH
NH
BH
NH
BN NH
BH
HN
HB
3.4
1032
Cs
B
NB
N
BN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BN
BH
HN
BH
HN
HB
HN
HB
HNBH
NH HNBH
NH
BH
1.4
104
Cs
B
NB
N
BN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BH
N
B
HN
BN
BN
BH
HN
HB
HN
HB
HNBH
NH
NH
BH
HN
HB
HNBH
NH
BH
1.2
105
C2v
B
NB
N
BN
BH
N
B
HN
BN
BN
BH
HN
HB
HN
HB
HNBH
NH
BH
NH
N
BH
HN
HB
HNB
HNBH
N
B
BH
N
B
HN
BH
NH
BH
HN
0.0
106
C1
Figure 4. Optimized (B3LYP/6-311G(d, p)) structures for BN-acenes (31-106), their increasing number of rings and π-sextets , relative Gibbs free energies (kcal mol-1) of isomers and symmetries.
12
5.3
31'
D2h
32'
0.0 C2v
41'
10.3 D2h
43'
0.0 C1
51'
16.7 D2h
53'
0.0 C2h
61'
23.2 D2h
64'
0.0 Cs
71'
28.6 D2h
75'
0.0 D2h
81'
34.2 D2h
85'
0.0 Cs
91'
43.6 D2h
96'
0.0 C1
101'
48.5 D2h
106'
0.0 C1
Figure 5. Optimized (B3LYP/6-311G(d, p)) structures for PBHs (31’-106’), their increasing number of rings and π-sextets , relative Gibbs free energies (kcal mol-1) of isomers and symmetries.
13
Results and discussion
Figure 6. Plot of the ring number (n = 3 - 10) of [n]acenes number against the energy differences of the most and least stable isomers.
14
15
Conclusion
1. Different aromatic indices indicated BN analogues has less aromaticity and even nonaromaticity.
2. More π-sextets containing, more stable the structure is.
3.Clar structures in inorganic BN analogues does exist according to the correlation (r2 = 0.975) between the ring number (n = 3 - 10) of BN analogues of [n]acenes number and energy differences of the most and least stable isomers.
Questions
BHN
HB
HN BH
N B
N
BN
HN BH
NH
BH
NH
BHHN
HB
0.0
HB N
B
NHHB
HN
HB NH
B
N
N
B
NHHB
HB NH
BH
NH
-0.5
N
BN
B
NB
NH
B
N
HB
NH
BH
NB
NH
HB
HN
HB
HN
HBNH
BH
BH
NH
HB
HN
0.0
HB
HN
HB NH
B
N
B
N
NH
B
NB
N
B
NHHB
HB NH
B
N
NHHB
NH
BH
NHHB
-0.2
B
NB
N
BN
BH
N
B
HN
BN
BN
BH
HN
HB
HN
HB
HNBH
NH
BH
NH
NH
BH
HN
HB
HNBH
0.0
BHN
HB
HN BH
N B
N
BHHN
HN BH
N
B
B
N
BHHN
HN BH
N
B
B
N
BHHN
HN BH
NH
BH
-0.3
B
NB
N
BN
BH
N
B
HN
BN
BN
BH
HN
HB
HN
HB
HNBH
NH
BH
NH
N
BH
HN
HB
HNB
HNBH
NH
BH
0.0
HB
HN
HB NH
B
N
B
N
NH
B
NB
N
B
NHHB
HB NH
B
N
NHHB
N
B
NHHB
HB NH
B
N
NH
BH
NHHB
-0.7
B
NB
N
BN
BH
N
B
HN
BN
BN
BH
HN
HB
HN
HB
HNBH
NH
BH
NH
N
BH
HN
HB
HNB
HNBH
N
B
BH
NH
BH
HN
0.0
HB
HN
HB NH
B
N
B
N
NH
B
NB
N
B
NHHB
HB NH
B
N
NHHB
N
B
NHHB
HB NH
B
N
N
B
NHHB
HB NH
BH
NH
-1.0
B
NB
N
BN
BH
N
B
HN
BN
BN
BH
HN
HB
HN
HB
HNBH
NH
BH
NH
N
BH
HN
HB
HNB
HNBH
N
B
BH
N
B
HN
BH
NH
BH
HN
0.0
HB
HN
HB NH
B
N
B
N
NH
B
NB
N
B
NHHB
HB NH
B
N
NHHB
N
B
NHHB
HB NH
B
N
N
B
NHHB
HB NH
B
N
NH
BH
NHHB
-1.8
How to explain
this situation
?
16
Figure 7. Optimized (B3LYP/6-311G(d, p)) structures for BN analogues, their increasing number of rings and π-sextets , relative Gibbs free energies (kcal mol-1) of isomers.