# Crystal Structure, Spectral Studies, and Hirshfeld Surfaces Analysis of 5-Methyl-5H-dibenzo[b,f]azepine and 5-(4-Methylbenzyl)-5H-dibenzo[b,f]azepine

Authors: Madan Kumar Shankar; Basavapattana C. Manjunath; Koravangala Shivakumar Vinay Kumar; Kudigana J. Pampa; Marilinganadoddi P. Sadashiva; Neartur K. Lokanath
Journal: Journal of Crystallography
 (2014)

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## Abstract

The compounds, 5-methyl-5H-dibenzo[b,f]azepine (1) and 5-(4-methylbenzyl)-5H-dibenzo[b,f]azepine (2), were synthesized and characterized by spectral studies, and finally confirmed by single crystal X-ray diffraction method. The compound 1 crystallizes in the orthorhombic crystal system in Pca21 space group, having cell parameters a=11.5681 (18) Å, b=11.8958 (18) Å, c=8.0342 (13) Å, and Z=4 and V=1105.6 (3) Å3. And the compound 2 crystallizes in the orthorhombic crystal system and space group Pbca, with cell parameters a=16.5858 (5) Å, b=8.4947 (2) Å, c=23.1733 (7) Å, and Z=8 and V=3264.92 (16) Å3. The azepine ring of both molecules 1 and 2 adopts boat conformation with nitrogen atom showing maximum deviations of 0.483 (2) Å and 0.5025 (10) Å, respectively. The C–H⋯π short contacts were observed. The dihedral angle between fused benzene rings to the azepine motif is 47.1 (2)° for compound 1 and 52.59 (6)° for compound 2, respectively. The short contacts were analyzed and Hirshfeld surfaces computational method for both molecules revealed that the major contribution is from C⋯H and H⋯H intercontacts.


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## Body

## 1. Introduction

Azepine derivatives have showed to be associated with different pharmacological activities such as antiviral, anticancer, anti-insecticidal, and vasopressin antagonist. Iminostilbene derivatives are found in montainine, coccinine, manthine, and pancracine alkaloids present inHaemanthus andRhodophiala species [1]. They are the derivatives of drugs, such as carbamazepine [2], opipramol [3], and oxcarbazepine [4], which are used as anticonvulsants and antidepressants and in the treatment of epilepsy and trigeminal neuralgia [5]. Another compound, G32883, an iminostilbene derivative, shows effect on peripheral nerves [6]. Recently, it is reported that carbamazepine with magnesium oxide is used to treat anticonvulsant in albino rats [7]. Lateral dibenzazepine moieties are known to have potential to act as substituents for the binding site of the acetylcholine M2 receptor [8]. The 11-phenyl-[b,e]-dibenzazepine compounds are proved to be novel antitumor compounds [9].Synthesis and crystal structures of other iminostilbene derivatives, 5-(prop-2-yn-1-yl)-5H-dibenzo[b,f]-azepine, orthorhombic polymorph, and 5-[(4-Benzyl-1H-1,2,3-triazol-1-yl)methyl]-5H-dibenzo[b,f]azepine have been reported [10, 11]. As a part of our ongoing research on the synthesis and crystal structures and their importance of iminostilbene derivatives, we report here the synthesis and characterization by spectral studies and crystal structure using single crystal X-ray crystal diffraction of compounds 5-methyl-5H-dibenzo[b,f]azepine (1) and 5-(4-methylbenzyl)-5H-dibenzo[b,f]azepine (2). Here, we investigate the role of the main intermolecular interactions on stabilization of the solid state architecture of the iminostilbene derivatives. And, Hirshfeld surface analysis and fingerprint plots analyzing intermolecular interactions were presented in the same procedure as we reported [12].


## 2. Material and Methods

### 2.1. Synthesis of 5-Methyl-5H-dibenzo[b,f]azepine (1)

5H-Dibenzo[b,f]azepine (0.0025 mol) was taken in dimethylformamide (DMF) solvent, and K2CO3 (0.0038 mol) was added at room temperature and stirred for 5 minutes. The reaction mixture was cooled to 0°C, then iodomethane was added (0.0038 mol). After 15 minutes, the resulting reaction mixture was heated at 60°C for 7 hours (Scheme 1). After completion of reaction (monitored by TLC), the reaction mixture was diluted with water (50 mL). The aqueous layer was extracted with ethyl acetate (3*20 mL), and the combined ethyl acetate layer was washed with 0.1 N hydrochloric acid (2*25 mL), followed by brine solution (2*25 mL). Then, the organic layer was dried over anhydrous sodium sulfate and filtered and concentrated under reduced pressure to afford crude product, which was purified by column chromatography over silica gel (60–120 mesh) using hexane : ethyl acetate mixture in 9.5 : 0.5 ratios as eluent. The pure compound was crystallized in ethyl acetate and hexane to obtain yellow hexagonal shaped single crystals.Scheme 1
The synthesis of compound1.


### 2.2. Spectral Data

1H NMR (CDCl3, 400 MHz); δ 7.21 (q, J=4.99 Hz, 2H), 7.01–6.91 (m, 6H), 6.66 (d, J=7.82 Hz, 2H), and 3.30 (d, J=7.82Hz, 2H).
Mass: Calc. 207.27 found: 208.27 (M++1).
13C NMR (100 MHz, CDCl3): δ 152.28, 132.81, 132.42, 129.21, 128.90, 123.15, 118.82, and 39.30.
MS:m/z=207.27 (calculated) m/z=208.27 [M+H]+ (found). Anal. Calcd. for C22H19N2: C, 86.92; H, 6.32; N, 6.76.(We also performed DEPT (distortionless enhancement by polarization transfer), which will be given as supplementary data in Supplementary Material available online athttp://dx.doi.org/10.1155/2014/862067.)


### 2.3. Synthesis of 5-(4-Methylbenzyl)-5H-dibenzo[b,f]azepine (2)

5H-Dibenzo[b,f]azepine (0.0025 mol) was taken in a mixture of toluene and water in the ratio of 1 : 1, and sodium hydroxide (0.029 mol) was added followed by tetra-n-butylammonium bromide (TBAB) (0.00029 mol) at room temperature. After 15 minutes, 1-(chloromethyl)-4-methylbenzene (0.0031 mol) was added to the reaction mixture at room temperature. Then, the resulting reaction mixture was heated at 60°C for 5 hours (Scheme 2). After completion of reaction (monitored by TLC), the reaction mixture was diluted with water (50 mL). The aqueous layer was extracted with ethyl acetate (3*20 mL), and the combined ethyl acetate layer was washed with 0.1 N hydrochloric acid (2*25 mL), followed by brine solution (2*25 mL). Then, the organic layer was dried over anhydrous sodium sulfate and filtered and concentrated under reduced pressure to afford crude product, which was purified by column chromatography over silica gel (60–120 mesh) using hexane: ethyl acetate mixture in 9.5 : 0.5 ratios as eluent. The pure compound was crystallized in ethyl acetate and hexane, which yields colorless needle single crystals.Scheme 2
The synthesis of compound2.


### 2.4. Spectral Data

1H NMR (CDCl3, 400 MHz); δ 7.31 (d, J=7.56 Hz, 2H), 7.15 (T, J=7.78 Hz, 2H), 7.05–6.99 (m, 6H), 6.92 (T, J=7.34 Hz, 2H), 6.79 (s, 2H), 4.91 (s, 2H), and 2.16 (s, 3H).
Mass: Calc. 297.39 found: 298.39 (M++1).
13C NMR (100 MHz, CDCl3):δ 150.52, 135.87, 134.51, 133.48, 131.92, 128.87, 128.70, 128.53, 128.28, 128.13, 127.50, 122.90, 120.15, 54.32, and 20.70.
MS:m/z=297.39 (calculated) m/z=298.39 [M+H]+ (found). Anal. Calcd. for C22H19N: C, 88.85; H, 6.44; N, 4.71.(We also performed DEPT (distortionless enhancement by polarization transfer), which will be given as supplementary data.)


### 2.5. Single Crystal X-Ray Diffraction Studies

X-ray intensity data were collected for1 (hexagonal shaped) and2 (needle shaped) using Bruker X8 Proteum diffractometer at 296 K and 100 K, respectively. Data were collected usingCuKα radiation (λ=1.54178 Å) with the φ and ω scan method [13]. The final unit cell parameters were based on all reflections. Data collections, integration, and scaling of the reflections were performed using the APEX2 program [13].The structures were solved by direct methods using SHELXS [14] and all of the nonhydrogen atoms were refined anisotropically by full-matrix least-squares on F2 using SHELXL [14]. Summary of crystal data, data collection procedures, structure determination methods, and refinement results are summarized in Table 1.Table 1
Crystal data, data collection, and structure refinement.
Compound
1
2
Empirical formula
C15 H13 N1
C22 H19 N1
Formula weight
207.26
297.38
Temperature (K)
296
100
Wavelength (Å)
1.54178
1.54178
Crystal system
Orthorhombic
Orthorhombic
Space group
Pca2
1
Pbca
Unit cell dimension (Å)
a
=
11.5681(18)
A
=
16.5858(5)
b
=
11.8958(18)
b
=
8.4947(2)
c
=
8.0342(13)
c
=
23.1733(7)
VolumeÅ3
1105.6(3)
3264.92(16)
Z
4
8
Calculated density g/cm3
1.245
1.210
Absorption coefficient mm−1
0.554
0.530
F
(
000
)
440
1264
Crystal size mm3
0.20
×
0.20
×
0.21
0.21
×
0.21
×
0.22
Theta range for data collection (°)
3.7 to 64.2
6.2 to 64.4
Limiting indices
-
13
≤
h
≤
12
-
18
≤
h
≤
19
-
13
≤
k
≤
13
-
9
≤
k
≤
9
-
6
≤
l
≤
9
-
27
≤
l
≤
26
Reflectionscollected/unique
9156/1417 R(int) = 0.130
54177/2696 R(int) = 0.034
Refinement method
Full-matrix least squares onF2
Full-matrix least squares onF2
Data/restraints/parameters
1417/1/146
2696/0/209
Goodness-of-fit onF2
1.16
1.08
FinalR indices [I>2σ(I)]
R
1
=
0.0786, wR2=0.2070
R
1
=
0.0385, wR2=0.0895
Largest diff. peak and hole
−0.32 and 0.28eÅ-3
−0.17 and 0.20eÅ-3
CCDC
959827
958853ORTEP (Figures1 and 2) and packing diagrams (Figures 3 and 4) were generated using MERCURY [15]. And the program Crystal Explorer 3.0 [16] was used to perform Hirshfeld surfaces computational analysis and to quantify the intermolecular interactions in terms of surface contribution and generating graphical representations (Figure 5), plotting 2D fingerprint plots (Figures 6 and 8) [17], and generating electrostatic potential (Figure 5) [18] with TONTO [19]. The electrostatic potential is mapped on Hirshfeld surfaces using Hartree-Fock (STO-3G basis set) theory over the range of −0.020 a.u. to +0.020 a.u. (Figures 5 and 7). The electrostatic potential surfaces are plotted with red region which is a negative electrostatic potential (hydrogen acceptors) and blue region which is a positive electrostatic potential (hydrogen donor).Figure 1
The molecular structure of compound1 showing the atomic numbering system. Displacement ellipsoids are drawn at the 30% probability.Figure 2
The crystal packing of compound1 projected onto bc plane.Figure 3
The molecular structure of compound2 showing the atomic numbering system. Displacement ellipsoids are drawn at the 50% probability.Figure 4
The crystal packing of compound2 projected onto ac plane.d
norm
⁡ mapped on Hirshfeld surface (b) for visualizing the intercontacts of compound1. Color scale in between −0.047 au (blue) and 1.152 au (red). Electrostatic potential mapped (c) on Hirshfeld surface (different orientation) with ±0.020 au. Blue region corresponds to positive electrostatic potential and red region to negative electrostatic potential. The ball and stick model represents the different orientations (front, back, top, and bottom) and correspondingly the Hirshfeld surfaces and their electrostatic potentials are oriented.
(a)
(b)
(c)Fingerprint of compound1: (a) C⋯H, (b) N⋯H, (c) C⋯C, and (d) C⋯H. The outline of the full fingerprint is shown in gray.di is the closest internal distance from a given point on the Hirshfeld surface andde is the closest external contacts.
(a)
(b)
(c)
(d)d
norm
⁡ mapped on Hirshfeld surface (b) for visualizing the intercontacts of compound2. Color scale in between −0.075 au (blue) and 1.358 au (red). Electrostatic potential mapped (c) on Hirshfeld surface (different orientation) with ±0.020 au. Blue region corresponds to positive electrostatic potential and red region to negative electrostatic potential. The ball and stick model represents the different orientations (front, back, top, and bottom) and correspondingly the Hirshfeld surfaces and their electrostatic potentials are oriented.
(a)
(b)
(c)Fingerprint of compound2: (a) C⋯H and (b) H⋯H. The outline of the full fingerprint is shown in gray.di is the closest internal distance from a given point on the Hirshfeld surface andde is the closest external contacts.
(a)
(b)Crystallographic data (excluding structure factors) for the structure reported in this paper have been deposited with the Cambridge Crystallographic Data Center as supplementary publications numbers 959827 (1) and 958853 (2).


## 2.1. Synthesis of 5-Methyl-5H-dibenzo[b,f]azepine (1)

5H-Dibenzo[b,f]azepine (0.0025 mol) was taken in dimethylformamide (DMF) solvent, and K2CO3 (0.0038 mol) was added at room temperature and stirred for 5 minutes. The reaction mixture was cooled to 0°C, then iodomethane was added (0.0038 mol). After 15 minutes, the resulting reaction mixture was heated at 60°C for 7 hours (Scheme 1). After completion of reaction (monitored by TLC), the reaction mixture was diluted with water (50 mL). The aqueous layer was extracted with ethyl acetate (3*20 mL), and the combined ethyl acetate layer was washed with 0.1 N hydrochloric acid (2*25 mL), followed by brine solution (2*25 mL). Then, the organic layer was dried over anhydrous sodium sulfate and filtered and concentrated under reduced pressure to afford crude product, which was purified by column chromatography over silica gel (60–120 mesh) using hexane : ethyl acetate mixture in 9.5 : 0.5 ratios as eluent. The pure compound was crystallized in ethyl acetate and hexane to obtain yellow hexagonal shaped single crystals.Scheme 1
The synthesis of compound1.


## 2.2. Spectral Data

1H NMR (CDCl3, 400 MHz); δ 7.21 (q, J=4.99 Hz, 2H), 7.01–6.91 (m, 6H), 6.66 (d, J=7.82 Hz, 2H), and 3.30 (d, J=7.82Hz, 2H).
Mass: Calc. 207.27 found: 208.27 (M++1).
13C NMR (100 MHz, CDCl3): δ 152.28, 132.81, 132.42, 129.21, 128.90, 123.15, 118.82, and 39.30.
MS:m/z=207.27 (calculated) m/z=208.27 [M+H]+ (found). Anal. Calcd. for C22H19N2: C, 86.92; H, 6.32; N, 6.76.(We also performed DEPT (distortionless enhancement by polarization transfer), which will be given as supplementary data in Supplementary Material available online athttp://dx.doi.org/10.1155/2014/862067.)


## 2.3. Synthesis of 5-(4-Methylbenzyl)-5H-dibenzo[b,f]azepine (2)

5H-Dibenzo[b,f]azepine (0.0025 mol) was taken in a mixture of toluene and water in the ratio of 1 : 1, and sodium hydroxide (0.029 mol) was added followed by tetra-n-butylammonium bromide (TBAB) (0.00029 mol) at room temperature. After 15 minutes, 1-(chloromethyl)-4-methylbenzene (0.0031 mol) was added to the reaction mixture at room temperature. Then, the resulting reaction mixture was heated at 60°C for 5 hours (Scheme 2). After completion of reaction (monitored by TLC), the reaction mixture was diluted with water (50 mL). The aqueous layer was extracted with ethyl acetate (3*20 mL), and the combined ethyl acetate layer was washed with 0.1 N hydrochloric acid (2*25 mL), followed by brine solution (2*25 mL). Then, the organic layer was dried over anhydrous sodium sulfate and filtered and concentrated under reduced pressure to afford crude product, which was purified by column chromatography over silica gel (60–120 mesh) using hexane: ethyl acetate mixture in 9.5 : 0.5 ratios as eluent. The pure compound was crystallized in ethyl acetate and hexane, which yields colorless needle single crystals.Scheme 2
The synthesis of compound2.


## 2.4. Spectral Data

1H NMR (CDCl3, 400 MHz); δ 7.31 (d, J=7.56 Hz, 2H), 7.15 (T, J=7.78 Hz, 2H), 7.05–6.99 (m, 6H), 6.92 (T, J=7.34 Hz, 2H), 6.79 (s, 2H), 4.91 (s, 2H), and 2.16 (s, 3H).
Mass: Calc. 297.39 found: 298.39 (M++1).
13C NMR (100 MHz, CDCl3):δ 150.52, 135.87, 134.51, 133.48, 131.92, 128.87, 128.70, 128.53, 128.28, 128.13, 127.50, 122.90, 120.15, 54.32, and 20.70.
MS:m/z=297.39 (calculated) m/z=298.39 [M+H]+ (found). Anal. Calcd. for C22H19N: C, 88.85; H, 6.44; N, 4.71.(We also performed DEPT (distortionless enhancement by polarization transfer), which will be given as supplementary data.)


## 2.5. Single Crystal X-Ray Diffraction Studies

X-ray intensity data were collected for1 (hexagonal shaped) and2 (needle shaped) using Bruker X8 Proteum diffractometer at 296 K and 100 K, respectively. Data were collected usingCuKα radiation (λ=1.54178 Å) with the φ and ω scan method [13]. The final unit cell parameters were based on all reflections. Data collections, integration, and scaling of the reflections were performed using the APEX2 program [13].The structures were solved by direct methods using SHELXS [14] and all of the nonhydrogen atoms were refined anisotropically by full-matrix least-squares on F2 using SHELXL [14]. Summary of crystal data, data collection procedures, structure determination methods, and refinement results are summarized in Table 1.Table 1
Crystal data, data collection, and structure refinement.
Compound
1
2
Empirical formula
C15 H13 N1
C22 H19 N1
Formula weight
207.26
297.38
Temperature (K)
296
100
Wavelength (Å)
1.54178
1.54178
Crystal system
Orthorhombic
Orthorhombic
Space group
Pca2
1
Pbca
Unit cell dimension (Å)
a
=
11.5681(18)
A
=
16.5858(5)
b
=
11.8958(18)
b
=
8.4947(2)
c
=
8.0342(13)
c
=
23.1733(7)
VolumeÅ3
1105.6(3)
3264.92(16)
Z
4
8
Calculated density g/cm3
1.245
1.210
Absorption coefficient mm−1
0.554
0.530
F
(
000
)
440
1264
Crystal size mm3
0.20
×
0.20
×
0.21
0.21
×
0.21
×
0.22
Theta range for data collection (°)
3.7 to 64.2
6.2 to 64.4
Limiting indices
-
13
≤
h
≤
12
-
18
≤
h
≤
19
-
13
≤
k
≤
13
-
9
≤
k
≤
9
-
6
≤
l
≤
9
-
27
≤
l
≤
26
Reflectionscollected/unique
9156/1417 R(int) = 0.130
54177/2696 R(int) = 0.034
Refinement method
Full-matrix least squares onF2
Full-matrix least squares onF2
Data/restraints/parameters
1417/1/146
2696/0/209
Goodness-of-fit onF2
1.16
1.08
FinalR indices [I>2σ(I)]
R
1
=
0.0786, wR2=0.2070
R
1
=
0.0385, wR2=0.0895
Largest diff. peak and hole
−0.32 and 0.28eÅ-3
−0.17 and 0.20eÅ-3
CCDC
959827
958853ORTEP (Figures1 and 2) and packing diagrams (Figures 3 and 4) were generated using MERCURY [15]. And the program Crystal Explorer 3.0 [16] was used to perform Hirshfeld surfaces computational analysis and to quantify the intermolecular interactions in terms of surface contribution and generating graphical representations (Figure 5), plotting 2D fingerprint plots (Figures 6 and 8) [17], and generating electrostatic potential (Figure 5) [18] with TONTO [19]. The electrostatic potential is mapped on Hirshfeld surfaces using Hartree-Fock (STO-3G basis set) theory over the range of −0.020 a.u. to +0.020 a.u. (Figures 5 and 7). The electrostatic potential surfaces are plotted with red region which is a negative electrostatic potential (hydrogen acceptors) and blue region which is a positive electrostatic potential (hydrogen donor).Figure 1
The molecular structure of compound1 showing the atomic numbering system. Displacement ellipsoids are drawn at the 30% probability.Figure 2
The crystal packing of compound1 projected onto bc plane.Figure 3
The molecular structure of compound2 showing the atomic numbering system. Displacement ellipsoids are drawn at the 50% probability.Figure 4
The crystal packing of compound2 projected onto ac plane.d
norm
⁡ mapped on Hirshfeld surface (b) for visualizing the intercontacts of compound1. Color scale in between −0.047 au (blue) and 1.152 au (red). Electrostatic potential mapped (c) on Hirshfeld surface (different orientation) with ±0.020 au. Blue region corresponds to positive electrostatic potential and red region to negative electrostatic potential. The ball and stick model represents the different orientations (front, back, top, and bottom) and correspondingly the Hirshfeld surfaces and their electrostatic potentials are oriented.
(a)
(b)
(c)Fingerprint of compound1: (a) C⋯H, (b) N⋯H, (c) C⋯C, and (d) C⋯H. The outline of the full fingerprint is shown in gray.di is the closest internal distance from a given point on the Hirshfeld surface andde is the closest external contacts.
(a)
(b)
(c)
(d)d
norm
⁡ mapped on Hirshfeld surface (b) for visualizing the intercontacts of compound2. Color scale in between −0.075 au (blue) and 1.358 au (red). Electrostatic potential mapped (c) on Hirshfeld surface (different orientation) with ±0.020 au. Blue region corresponds to positive electrostatic potential and red region to negative electrostatic potential. The ball and stick model represents the different orientations (front, back, top, and bottom) and correspondingly the Hirshfeld surfaces and their electrostatic potentials are oriented.
(a)
(b)
(c)Fingerprint of compound2: (a) C⋯H and (b) H⋯H. The outline of the full fingerprint is shown in gray.di is the closest internal distance from a given point on the Hirshfeld surface andde is the closest external contacts.
(a)
(b)Crystallographic data (excluding structure factors) for the structure reported in this paper have been deposited with the Cambridge Crystallographic Data Center as supplementary publications numbers 959827 (1) and 958853 (2).


## 3. Results and Discussion

The X-ray crystallographic analysis of1 and2 was performed, confirming the structures previously established by the NMR data. The crystal structure of each compound presents only one molecule in the asymmetric unit. The ORTEP diagrams of1 and2 including the atoms labeled are shown in Figures 1 and 3, respectively. The compounds1 and2 crystallize in the centrosymmetric and noncentrosymmetric space groupsPbca andPca21, respectively. The structural analysis reveals that all geometric parameters agree well with the expected values reported in the literature, including the iminostilbene derivatives previously published by us [10, 11]. Overall, both the molecules adopt butterfly shape and the percentage of intercontacts of1 and2 to the Hirshfeld surface is compared (Figure 9).Figure 9
Hirshfeld surfaces percentage evaluation of short contacts for compound1 and compound 2. The particular squared colour boxes on the right side represent the type of the intercontact visible at the percentage evaluation boxes.


### 3.1. Compound 1

The fused benzene ring (C1–C5/C15 and C9–C14) to the azepine motif makes a dihedral angle of 47.1(2)°. Seven-membered (azepine) ring adopts a boat conformation with nitrogen atom showing maximum deviations of 0.483 (2) Å, the puckering parametersQ2=0.663(5) Å, φ2=182.1(4)°, Q3=0.2050(4) Å, and φ3=179.7(15)°, and the total puckering amplitude QT=0.6940(4) Å [20]. TheORTEP of compound1 is shown in Figure 1. The packing (Figure 2) of the molecules is stabilized with the short contacts C–H⋯π (Table 2), which exist between C12—H12 and the centroid (Cg(1): C1–C5/C15) of the ring of the neighboring molecules with a distance of 0.930 Å.Table 2
Intermolecular interactions geometry [Å, °].
D–H⋯A
D–H (Å)
H–A (Å)
D–A (Å)
D–H⋯A(°)
1
C12–H12⋯Cg(1)iii
2.895
0.9300
3.775 (12)
166.41
2
C3–H3⋯Cg(1)i
2.990
0.7613
3.7513 (15)
141
C7–H7⋯Cg(2)ii
2.880
0.8726
3.7526 (14)
156
C8–H8⋯Cg(1)ii
2.620
0.8787
3.4987 (14)
159
i
x
-
1
/
2, y-1/2, and z; iix-1, y+1/2, and z-1/2; iii-x, y-2, and z-1/2.


### 3.2. Hirshfeld Surface Analysis

Here, we estimated the intermolecular intercontacts contributing to the Hirshfeld surfaces shown in Figures5 and 9. It shows that the major contribution is from C–H (39%) (Figures 6(d) and 9) and H–H (57%) (Figures 6(a) and 9). This is evidence that van der Waals forces exert an important influence on the stabilization of the packing in1. And other intercontacts C–C (2%) (Figures 6(c) and 9) and N–H (2%) (Figures 6(b) and 9) contribute less to the Hirshfeld surfaces. The mentioned intercontacts are highlighted by conventional mapping dnorm⁡ on the molecular Hirshfeld surfaces (Figure 5), where the red spot areas indicate intercontacts involved in the C–H⋯π interactions. And the electrostatic potential (Figure 7) shows the distribution of positive and negative potential over the Hirshfeld surfaces.


### 3.3. Compound 2

The fused benzene rings (C1–C6 and C9–C14) to azepine motif make a dihedral angle of 52.59(6)°. The terminal benzene ring (C17–C22) makes dihedral angles of 26.66(6)° and 77.06(6)° with benzene rings C1–C6 and C9–C14, respectively. TheORTEP of the compound2 is shown in Figure 3. Seven-membered (azepine) ring adopts a boat conformation with nitrogen atom showing maximum deviations of 0.5025 (10) Å, the puckering parameters Q2=0.7030(13) Å, φ2=1.07(11)°, Q3=0.2025(12) Å, and φ3=359.2(12)°, and the total puckering amplitude QT=0.7315(12) Å [20]. The packing (Figure 4) of the molecules is stabilized with the short contacts of the type C–H⋯π (Table 2). These short contacts exist between C3–H3⋯Cg(1) with a distance 3.7513 (15) Å (angle 141°), C7–H7….Cg(2) with a distance of 3.7526 (14) Å (angle 156°), and C8–H8⋯Cg(1) with a distance 3.4987 (14) Å (angle 159°), withCg(1): C1–C6;Cg(2): C9–C14.


### 3.4. Hirshfeld Surface Analysis

The major contribution is from C—H (39%) (Figures8(b) and 9) and H–H (61%) (Figures 8(a) and 9) intercontacts. The mentioned intercontacts are highlighted by conventional mapping dnorm⁡ on the molecular Hirshfeld surfaces (Figure 7). In Figure 7, the red spot areas indicate intercontacts involved in the C–H⋯π interactions. And the electrostatic potential (Figure 7) shows the distribution of positive and negative potential over the Hirshfeld surfaces.


## 3.1. Compound 1

The fused benzene ring (C1–C5/C15 and C9–C14) to the azepine motif makes a dihedral angle of 47.1(2)°. Seven-membered (azepine) ring adopts a boat conformation with nitrogen atom showing maximum deviations of 0.483 (2) Å, the puckering parametersQ2=0.663(5) Å, φ2=182.1(4)°, Q3=0.2050(4) Å, and φ3=179.7(15)°, and the total puckering amplitude QT=0.6940(4) Å [20]. TheORTEP of compound1 is shown in Figure 1. The packing (Figure 2) of the molecules is stabilized with the short contacts C–H⋯π (Table 2), which exist between C12—H12 and the centroid (Cg(1): C1–C5/C15) of the ring of the neighboring molecules with a distance of 0.930 Å.Table 2
Intermolecular interactions geometry [Å, °].
D–H⋯A
D–H (Å)
H–A (Å)
D–A (Å)
D–H⋯A(°)
1
C12–H12⋯Cg(1)iii
2.895
0.9300
3.775 (12)
166.41
2
C3–H3⋯Cg(1)i
2.990
0.7613
3.7513 (15)
141
C7–H7⋯Cg(2)ii
2.880
0.8726
3.7526 (14)
156
C8–H8⋯Cg(1)ii
2.620
0.8787
3.4987 (14)
159
i
x
-
1
/
2, y-1/2, and z; iix-1, y+1/2, and z-1/2; iii-x, y-2, and z-1/2.


## 3.2. Hirshfeld Surface Analysis

Here, we estimated the intermolecular intercontacts contributing to the Hirshfeld surfaces shown in Figures5 and 9. It shows that the major contribution is from C–H (39%) (Figures 6(d) and 9) and H–H (57%) (Figures 6(a) and 9). This is evidence that van der Waals forces exert an important influence on the stabilization of the packing in1. And other intercontacts C–C (2%) (Figures 6(c) and 9) and N–H (2%) (Figures 6(b) and 9) contribute less to the Hirshfeld surfaces. The mentioned intercontacts are highlighted by conventional mapping dnorm⁡ on the molecular Hirshfeld surfaces (Figure 5), where the red spot areas indicate intercontacts involved in the C–H⋯π interactions. And the electrostatic potential (Figure 7) shows the distribution of positive and negative potential over the Hirshfeld surfaces.


## 3.3. Compound 2

The fused benzene rings (C1–C6 and C9–C14) to azepine motif make a dihedral angle of 52.59(6)°. The terminal benzene ring (C17–C22) makes dihedral angles of 26.66(6)° and 77.06(6)° with benzene rings C1–C6 and C9–C14, respectively. TheORTEP of the compound2 is shown in Figure 3. Seven-membered (azepine) ring adopts a boat conformation with nitrogen atom showing maximum deviations of 0.5025 (10) Å, the puckering parameters Q2=0.7030(13) Å, φ2=1.07(11)°, Q3=0.2025(12) Å, and φ3=359.2(12)°, and the total puckering amplitude QT=0.7315(12) Å [20]. The packing (Figure 4) of the molecules is stabilized with the short contacts of the type C–H⋯π (Table 2). These short contacts exist between C3–H3⋯Cg(1) with a distance 3.7513 (15) Å (angle 141°), C7–H7….Cg(2) with a distance of 3.7526 (14) Å (angle 156°), and C8–H8⋯Cg(1) with a distance 3.4987 (14) Å (angle 159°), withCg(1): C1–C6;Cg(2): C9–C14.


## 3.4. Hirshfeld Surface Analysis

The major contribution is from C—H (39%) (Figures8(b) and 9) and H–H (61%) (Figures 8(a) and 9) intercontacts. The mentioned intercontacts are highlighted by conventional mapping dnorm⁡ on the molecular Hirshfeld surfaces (Figure 7). In Figure 7, the red spot areas indicate intercontacts involved in the C–H⋯π interactions. And the electrostatic potential (Figure 7) shows the distribution of positive and negative potential over the Hirshfeld surfaces.


## 4. Conclusions

Two derivatives, called 5-methyl-5H-dibenzo[b,f]azepine (1) and 5-(4-methylbenzyl)-5H-dibenzo[b,f]azepine (2), were synthesized, charactrized by spectral studies (1H NMR, 13C NMR and DEPT) and finally, structural elucidation by single crystal X-ray diffraction studies. The azepine rings of compounds1 and2 adopt the boat conformation, and, as a whole, molecule assumes butterfly shape. The fused benzene ring to azepine motif makes a dihedral angle of 47.1 (2)° for compound1 and 52.59 (6)° for compound2, respectively. Hirshfeld surface analysis of1 and2 reveals that H⋯H and C⋯H are the most abundant intercontacts. This is evidence that van der Waals forces exert an important influence on the stabilization of the packing in1 and2.



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*Source: 862067-2014-05-19.xml*