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Crystal structure and Hirshfeld analysis of 2-(5-bromo­thio­phen-2-yl)aceto­nitrile

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aDivision of Science and Mathematics, University of Minnesota, Morris, MN 56267, USA, and bDept. of Chemistry and Biochemistry, St. Catherine University, 20204 Randolph Avenue, St. Paul, MN 55105, USA
*Correspondence e-mail: dejanzen@stkate.edu

Edited by D. Chopra, Indian Institute of Science Education and Research Bhopal, India (Received 10 January 2018; accepted 15 January 2018; online 19 January 2018)

The title compound, C6H4BrNS, crystallizes in the space group P21/n with one complete mol­ecule in the asymmetric unit. The non-H atoms are nearly planar (r.m.s for non-H atoms = 0.071 Å), with the nitrile group oriented anti­periplanar with respect to the thio­phene S atom. Inter­molecular Type I centrosymmetric Br⋯Br halogen inter­actions are present at a distance of 3.582 (1) Å and with a C—Br⋯Br angle of 140.7 (1)°. Additional weaker C—H⋯N, C—H⋯S, and S⋯π inter­actions are also present. A Hirshfeld analysis indicates Br⋯Br inter­actions comprise only 1.9% of all the inter­atomic contacts.

1. Chemical context

Cyano-substituted mol­ecules have found widespread use as functional materials for a variety of applications in organic electronics (Kim & Lim, 2014[Kim, Y. & Lim, E. (2014). Polymers, 6, 382-407.]). For example, the title compound, 2-(5-bromo­thio­phen-2-yl)aceto­nitrile, has been incorporated into materials for use in organic semiconductors (Park et al., 2016[Park, J.-M., Park, S. K., Yoon, W. S., Kim, J. K., Kim, D. W., Choi, T.-L. & Park, S. Y. (2016). Macromolecules, 49, 2985-2992.]), sensors (Ding et al., 2015[Ding, J., Li, H., Wang, C., Yang, J., Xie, Y., Peng, Q., Li, Q. & Li, Z. (2015). Appl. Mater. Interfaces, 7, 11369-11376.]), dye-sensitized solar cells (Li et al., 2016[Li, H., Fang, M., Hou, Y., Tang, R., Yang, Y., Zhong, C., Li, Q. & Li, Z. (2016). Appl. Mater. Interfaces, 8, 12134-12140.]), and organic solar cells (Kwon et al., 2015[Kwon, O. K., Park, J.-H., Park, S. K. & Park, S. Y. (2015). Adv. Energ. Mater. 5, 1400929.]). Although the chemical literature has previously identified the title compound, 1, as a liquid (Cho et al., 2004[Cho, N. S., Hwang, D.-H., Jung, B.-J., Lim, E., Lee, J. & Shim, H.-K. (2004). Macromolecules, 37, 5265-5273.]; Chung et al., 2009[Chung, J. W., Yang, H., Singh, B., Moon, H., An, B., Lee, S. Y. & Park, S. Y. (2009). J. Mater. Chem. 19, 5920-5925.]; Lu et al., 2014[Lu, J., Peng, J., Wang, Y., Yuan, J., Sheng, C., Wang, H.-Q. & Ma, W. (2014). Synth. Met. 188, 57-65.]; Wan et al., 2009[Wan, M., Wu, W., Sang, G., Zou, Y., Liu, Y. & Li, Y. (2009). J. Polym. Sci. A Polym. Chem. 47, 4028-4036.]; Zou et al., 2009[Zou, Y., Liu, B., Li, Y., He, Y., Zhou, K. & Pan, C. (2009). J. Mater. Sci. 44, 4174-4180.]), we have found that with proper purification, this mol­ecule crystallizes under ambient conditions.

[Scheme 1]

2. Structural commentary

The mol­ecular structure of 1 is illustrated in Fig. 1[link]. The asymmetric unit is composed of one complete mol­ecule of 1. The C1—C2, C2—C3, and C3—C4 bond lengths are consistent with some conjugation in the thienyl π-system (Table 1[link]). While both the C4—C5 and C5—C6 bond lengths are consistent with single C—C bonds, the C5—C6 bond length is shorter, likely as a result of the sp hybridization at C6. Although conjugation across the mol­ecule is not evident from the pattern of bond lengths, the structure is remarkably planar with an r.m.s. deviation from planarity of 0.071 Å for all non-hydrogen atoms.

Table 1
Selected bond lengths (Å)

C1—C2 1.343 (6) C4—C5 1.523 (7)
C2—C3 1.436 (6) C5—C6 1.468 (7)
C3—C4 1.344 (7)    
[Figure 1]
Figure 1
A displacement ellipsoid plot (50% probability ellipsoids for non-H atoms) of the asymmetric unit of 1.

3. Supra­molecular Features

The structure packs with centrosymmetric ππ dimers, though the distance between least-squares planes formed by non-H atoms of the mol­ecules is beyond the sum of the van der Waals radii at 3.637 Å. Mol­ecules pack in a herringbone pattern with a dihedral angle of 65.2° between the least-squares planes formed by mol­ecules related by the 21 screw axis (Fig. 2[link]). The structure has several unique types of inter­molecular features. Each mol­ecule participates in centrosymmetric halogen-bonding dimers of Type I (Desiraju & Parthasarathy, 1989[Desiraju, G. R. & Parthasarathy, R. (1989). J. Am. Chem. Soc. 111, 8725-8726.]) with Br⋯Br contacts at 3.582 (1) Å and a C1—Br1⋯Br1 angle of 140.7 (1)° (Fig. 3[link]). Each mol­ecule also engages in two weaker C—H⋯N inter­actions, one as an sp3-hybridized C5—H5B donor and the other as an acceptor (N1) of this type of inter­action (Table 2[link], Fig. 4[link]). It is noteworthy that the two methyl­ene hydrogen atoms are acidic on account of the electron-withdrawing nature of the cyano group and hence their participation in the formation of C—H⋯N hydrogen bonds is significant. Additionally, atom S1 contributes to two unique inter­molecular inter­actions. S1 acts as acceptor for an inter­action with C3—H3 as the donor. These S⋯H inter­actions are organized in a C11(4) graph-set motif parallel to [101]. An edge-to-face S1⋯π(C1—C2 midpoint) inter­action is also present at a distance of 3.391 Å (sum of van der Waals radii = 3.50 Å). These S⋯π close contacts are organized in chains parallel to [010].

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
C3—H3⋯S1i 0.95 2.93 3.844 (5) 162
C5—H5B⋯N1ii 0.99 2.66 3.425 (7) 134
Symmetry codes: (i) [x+{\script{1\over 2}}, -y+{\script{1\over 2}}, z+{\script{1\over 2}}]; (ii) [-x+{\script{3\over 2}}, y-{\script{1\over 2}}, -z+{\script{5\over 2}}].
[Figure 2]
Figure 2
Packing diagram of 1 showing the herringbone packing pattern.
[Figure 3]
Figure 3
Inter­molecular halogen inter­action of 1. Symmetry code: (i) 2 − x, −y, 1 − z.
[Figure 4]
Figure 4
Inter­molecular inter­actions of 1. Br⋯Br inter­actions omitted for clarity. π indicates the C1—C2 midpoint. Symmetry codes: (i) [{3\over 2}] − x, −[{1\over 2}] + y, [{3\over 2}] − z; (ii) −[{1\over 2}] + x, [{1\over 2}] − y, −[{1\over 2}] + z; (iii) [{3\over 2}] − x, [{1\over 2}] + y, [{3\over 2}] − z; (iv) [{3\over 2}] − x, −[{1\over 2}] + y, [{5\over 2}] − z; (v) [{3\over 2}] − x, [{1\over 2}] + y, [{5\over 2}] − z; (vi) [{1\over 2}] + x, [{1\over 2}] − y, [{1\over 2}] + z.

4. Hirshfeld surface analysis

Inter­molecular inter­actions were studied further through analysis of the Hirshfeld surface, generated using CrystalExplorer (McKinnon et al. 2007[McKinnon, J. J., Jayatilaka, D. & Spackman, M. A. (2007). Chem. Commun. pp. 3814-3816.]; Spackman & Jayatilaka, 2009[Spackman, M. A. & Jayatilaka, D. (2009). CrystEngComm, 11, 19-32.]). Fig. 5[link] shows two orientations of the Hirshfeld surface mapped over dnorm. The red areas of the surface indicate negative dnorm values corresponding to contacts closer than the sum of van der Waals radii and highlight the relevant inter­molecular inter­actions discussed. The relative surface-area contributions from the particular inter­atomic contacts described for 1 to the total Hirshfeld surfaces are summarized in Table 3[link]. While N⋯H contacts comprise the largest percentage of contacts to the Hirshfeld surface described, the angular and distance components involved in the C—H⋯N hydrogen-bonding inter­actions do not suggest that these inter­actions dominate the packing. The Br⋯Br contacts comprise the smallest percentage of inter­atomic contacts described, however these Br⋯Br atom contacts [3.582 (1) Å] are the shortest of all the contacts described, relative to the van der Waals radii sums (−0.118 Å). The observation that C⋯C contacts comprise only a small percentage of the inter­atomic contacts is consistent with minor ππ stacking contributions and the observed stacking distance beyond the sum of the van der Waals radii.

Table 3
Percentage contributions of inter­atomic contacts to the Hirshfeld surface

Contact %
N⋯H/H⋯N 21.8
S⋯H/H⋯S 10.3
S⋯C/C⋯S 6.9
C⋯C 4.1
Br⋯Br 1.9
[Figure 5]
Figure 5
Hirshfeld surface of 1 mapped over dnorm, shown in two orientations in the range −0.0639 to 0.93667 a.u. Red areas highlight inter­molecular contacts shorter than the sum of the van der Waals radii.

5. Database Survey

A search of the current version of the Cambridge Structural Database (Version 5.39, updated November 2017; Groom et al., 2016[Groom, C. R., Bruno, I. J., Lightfoot, M. P. & Ward, S. C. (2016). Acta Cryst. B72, 171-179.]) yields a number of related structures with a 5-bromo­thio­phene fragment but only two non-salt structures with exclusively one small substituent in the 2-position. The structure of 2-acetyl-5-bromo­thio­phene (ACBTHO; Streur­man & Schenk, 1970[Streurman, H. J. & Schenk, H. (1970). Recl Trav. Chim. Pays Bas, 89, 392-394.]) is planar like 1, but the acetyl group is syn-periplanar relative to the sulfur of thio­phene, and Br⋯O=C inter­actions are present in the absence of Br⋯Br inter­actions. The structure of a co-crystal of 5-bromo­thio­phene-2-carb­oxy­lic acid with 5-fluoro­uracil (CAWCAP; Mohana et al., 2017[Mohana, M., Thomas Muthiah, P. & McMillen, C. D. (2017). Acta Cryst. C73, 481-485.]) is also similar, with no Br⋯Br inter­actions but the presence of Br⋯O=C inter­actions. No other structures of any substituted 2-thio­phene­aceto­nitrile have been reported.

The Type I Br⋯Br halogen-inter­action pattern of 1 is very similar to three other structures reported with only one bromine donor in the 5-position and no substitution in the 3- or 4-positions of the thio­phene group. The structures of 2-bromo-5-[4-(4-nitro­phen­yl)buta-1,3-dien-1-yl]thio­phene (MUJTUH; Kanibolotsky et al., 2009[Kanibolotsky, A. L., Forgie, J. C., McEntee, G. J., Talpur, M. M. A., Skabara, P. J., Westgate, T. D. J., McDouall, J. J. W., Auinger, M., Coles, S. J. & Hursthouse, M. B. (2009). Chem. Eur. J. 15, 11581-11593.]), (2E)-1-(5-bromo-2-thien­yl)-3-(4-ethyl­phen­yl)prop-2-en-1-one (PUSKUL; Naik et al., 2015[Naik, V. S., Yathirajan, H. S., Jasinski, J. P., Smolenski, V. A. & Glidewell, C. (2015). Acta Cryst. E71, 1093-1099.]), and (2RS,4SR)-2-exo-(5-bromo-2-thien­yl)-7-chloro-2,3,4,5-tetra­hydro-1H-1,4-ep­oxy-1-benzazepine (YUCTIA; Blanco et al., 2009[Blanco, M. C., Palma, A., Bahsas, A., Cobo, J. & Glidewell, C. (2009). Acta Cryst. C65, o487-o491.]) have short inter­molecular Br⋯Br contacts with distances of 3.4619 (4), 3.4917 (5), and 3.5234 (7) Å, respectively, and centrosymmetric inter­actions with C—Br⋯Br angles of 145.12 (9), 151.37 (8), and 143.8 (1)°, respectively.

6. Synthesis and Crystallization

The title compound, 2-(5-bromo­thio­phen-2-yl)aceto­nitrile, was prepared according to the literature procedure (Lu et al., 2014[Lu, J., Peng, J., Wang, Y., Yuan, J., Sheng, C., Wang, H.-Q. & Ma, W. (2014). Synth. Met. 188, 57-65.]). Additional purification was performed by vacuum distillation (b.p. 334 K @ 0.07 mm Hg), which provided a colorless liquid that crystallized over several days to afford colorless crystals (m.p. 302–305 K) suitable for X-ray diffraction. EI–MS m/z (relative intensity) 202.88 (29.9), 200.89 (29.7), 123.02 (8.6), 122.01 (100.0), 95.03 (11.1).

7. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 4[link]. H atoms were placed in calculated positions and refined in the riding-model approximation with distances of C—H = 0.95 and 0.99 Å for the thio­phene and methyl­ene groups, respectively, and with Uiso(H) = 1.2Ueq(C).

Table 4
Experimental details

Crystal data
Chemical formula C6H4BrNS
Mr 202.07
Crystal system, space group Monoclinic, P21/n
Temperature (K) 173
a, b, c (Å) 9.775 (4), 7.278 (3), 10.698 (4)
β (°) 110.933 (8)
V3) 710.8 (5)
Z 4
Radiation type Mo Kα
μ (mm−1) 6.00
Crystal size (mm) 0.51 × 0.44 × 0.22
 
Data collection
Diffractometer Rigaku XtaLAB mini
Absorption correction Multi-scan (REQAB; Rigaku, 1998[Rigaku (1998). REQAB. Rigaku Corporation, Tokyo, Japan.])
Tmin, Tmax 0.141, 0.267
No. of measured, independent and observed [F2 > 2.0σ(F2)] reflections 6585, 1444, 1198
Rint 0.048
(sin θ/λ)max−1) 0.625
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.048, 0.117, 1.07
No. of reflections 1444
No. of parameters 82
H-atom treatment H-atom parameters constrained
Δρmax, Δρmin (e Å−3) 0.55, −0.82
Computer programs: CrystalClear-SM Expert (Rigaku, 2011[Rigaku (2011). CrystalClear. Rigaku Americas, The Woodlands, Texas, USA, and Rigaku Corporation, Tokyo, Japan.]), SIR2004 (Burla et al., 2005[Burla, M. C., Caliandro, R., Camalli, M., Carrozzini, B., Cascarano, G. L., De Caro, L., Giacovazzo, C., Polidori, G. & Spagna, R. (2005). J. Appl. Cryst. 38, 381-388.]), SHELXL2013 (Sheldrick, 2015[Sheldrick, G. M. (2015). Acta Cryst. C71, 3-8.]), Mercury (Macrae et al., 2008[Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466-470.]), publCIF (Westrip, 2010[Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.]) and CrystalStructure (Rigaku, 2014[Rigaku (2014). CrystalStructure. Rigaku Corporation, Tokyo, Japan.]).

A single low-angle reflection was rejected from these high-quality data sets due to the arrangement of the instrument with a conservatively sized beam stop and a fixed-position detector. The large number of reflections in the data sets (and the Fourier-transform relationship of intensities to atoms) ensures that no particular bias was thereby introduced.

Supporting information


Computing details top

Data collection: CrystalClear-SM Expert (Rigaku, 2011); cell refinement: CrystalClear-SM Expert (Rigaku, 2011); data reduction: CrystalClear-SM Expert (Rigaku, 2011); program(s) used to solve structure: SIR2004 (Burla et al., 2005); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2015); molecular graphics: Mercury (Macrae et al., 2008) and publCIF (Westrip, 2010); software used to prepare material for publication: CrystalStructure (Rigaku, 2014).

2-(5-Bromothiophen-2-yl)acetonitrile top
Crystal data top
C6H4BrNSF(000) = 392.00
Mr = 202.07Dx = 1.888 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71075 Å
a = 9.775 (4) ÅCell parameters from 5750 reflections
b = 7.278 (3) Åθ = 3.5–26.5°
c = 10.698 (4) ŵ = 6.00 mm1
β = 110.933 (8)°T = 173 K
V = 710.8 (5) Å3Prism, colorless
Z = 40.51 × 0.44 × 0.22 mm
Data collection top
Rigaku XtaLAB mini
diffractometer
1198 reflections with F2 > 2.0σ(F2)
Detector resolution: 6.849 pixels mm-1Rint = 0.048
ω scansθmax = 26.4°, θmin = 3.5°
Absorption correction: multi-scan
(REQAB; Rigaku, 1998)
h = 1212
Tmin = 0.141, Tmax = 0.267k = 99
6585 measured reflectionsl = 1313
1444 independent reflections
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.048Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.117H-atom parameters constrained
S = 1.07 w = 1/[σ2(Fo2) + (0.0495P)2]
where P = (Fo2 + 2Fc2)/3
1444 reflections(Δ/σ)max < 0.001
82 parametersΔρmax = 0.55 e Å3
0 restraintsΔρmin = 0.82 e Å3
Primary atom site location: structure-invariant direct methods
Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Refinement. Refinement was performed using all reflections. The weighted R-factor (wR) and goodness of fit (S) are based on F2. R-factor (gt) are based on F. The threshold expression of F2 > 2.0 sigma(F2) is used only for calculating R-factor (gt).

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Br10.90954 (6)0.12818 (8)0.59072 (5)0.0348 (2)
S10.76060 (13)0.07396 (16)0.79952 (11)0.0242 (3)
N10.8679 (6)0.3162 (8)1.2745 (5)0.0610 (16)
C10.9070 (5)0.1545 (6)0.7644 (4)0.0218 (10)
C21.0043 (5)0.2468 (6)0.8663 (4)0.0258 (11)
H21.09140.30160.86340.031*
C30.9592 (5)0.2517 (6)0.9801 (5)0.0261 (11)
H31.01430.30931.06240.031*
C40.8308 (5)0.1662 (6)0.9581 (4)0.0220 (10)
C50.7453 (6)0.1396 (6)1.0510 (5)0.0314 (12)
H5A0.64370.18411.00630.038*
H5B0.74100.00711.07010.038*
C60.8137 (6)0.2395 (7)1.1774 (5)0.0382 (14)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.0342 (4)0.0494 (4)0.0253 (3)0.0001 (2)0.0160 (3)0.0028 (2)
S10.0219 (7)0.0271 (6)0.0233 (6)0.0037 (5)0.0077 (5)0.0011 (5)
N10.079 (5)0.077 (4)0.038 (3)0.001 (3)0.034 (3)0.012 (3)
C10.023 (3)0.025 (2)0.019 (2)0.0048 (19)0.0088 (19)0.0027 (17)
C20.016 (3)0.029 (3)0.032 (3)0.0024 (19)0.008 (2)0.0032 (19)
C30.026 (3)0.027 (3)0.021 (2)0.001 (2)0.005 (2)0.0052 (18)
C40.023 (3)0.024 (2)0.021 (2)0.0026 (19)0.009 (2)0.0022 (18)
C50.034 (3)0.036 (3)0.027 (3)0.000 (2)0.013 (2)0.002 (2)
C60.044 (4)0.049 (4)0.028 (3)0.011 (3)0.021 (3)0.006 (2)
Geometric parameters (Å, º) top
Br1—C11.877 (4)C3—C41.344 (7)
S1—C11.708 (5)C3—H30.9500
S1—C41.723 (4)C4—C51.523 (7)
N1—C61.131 (7)C5—C61.468 (7)
C1—C21.343 (6)C5—H5A0.9900
C2—C31.436 (6)C5—H5B0.9900
C2—H20.9500
C1—S1—C490.7 (2)C3—C4—C5129.8 (4)
C2—C1—S1113.5 (4)C3—C4—S1111.8 (3)
C2—C1—Br1126.8 (4)C5—C4—S1118.4 (3)
S1—C1—Br1119.4 (3)C6—C5—C4111.2 (4)
C1—C2—C3110.9 (4)C6—C5—H5A109.4
C1—C2—H2124.5C4—C5—H5A109.4
C3—C2—H2124.5C6—C5—H5B109.4
C4—C3—C2113.0 (4)C4—C5—H5B109.4
C4—C3—H3123.5H5A—C5—H5B108.0
C2—C3—H3123.5N1—C6—C5179.2 (6)
C4—S1—C1—C20.1 (4)C2—C3—C4—S10.8 (5)
C4—S1—C1—Br1174.5 (3)C1—S1—C4—C30.4 (4)
S1—C1—C2—C30.6 (5)C1—S1—C4—C5179.6 (4)
Br1—C1—C2—C3174.5 (3)C3—C4—C5—C65.7 (7)
C1—C2—C3—C40.9 (6)S1—C4—C5—C6175.2 (3)
C2—C3—C4—C5179.8 (4)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C3—H3···S1i0.952.933.844 (5)162
C5—H5B···N1ii0.992.663.425 (7)134
Symmetry codes: (i) x+1/2, y+1/2, z+1/2; (ii) x+3/2, y1/2, z+5/2.
Percentage contributions of interatomic contacts to the Hirshfeld surface top
Contact%
N···H/H···N21.8
S···H/H···S10.3
S···C/C···S6.9
C···C4.1
Br···Br1.9
 

Funding information

The authors acknowledge St. Catherine University and NSF–MRI award No. 1125975, MRI Consortium: Acquisition of a Single Crystal X-ray Diffractometer for a Regional PUI Mol­ecular Structure Facility. TMP acknowledges the following: (i) University of Minnesota, Morris (UMM) Faculty Research Enhancement Funds supported by the University of Minnesota Office of the Vice President for Research and the UMM Division of Science and Mathematics for financial assistance, and (ii) The Supercomputing Institute of the University of Minnesota. DEJ acknowledges the Carondelet Scholars program supported by St. Catherine University.

References

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