Two new polymorphs of 2,4,6-tribromobenzonitrile have been found. Together with the known polymorph, they are polytypic. One new polytype is isostructural with the previously reported crystal structure of 1,3,5-tribromo-2-isocyanobenzene.
Keywords: crystal structure, polytypes, polymorphs, Sandmeyer, isocyanide, N⋯Br contacts, C⋯Br contacts
Abstract
Three polymorphs of 2,4,6-tribromobenzonitrile (RCN), C7H2Br3N, two of which are novel and one of which is a redetermination of the original structure first determined by Carter & Britton [(1972). Acta Cryst. B28, 945–950] are found to be polytypic. Each has a layer structure which differs only in the stacking of the layers. Each layer is composed of molecules associated through C≡N⋯Br contacts which form R 2 2(10) rings. Two such rings are associated with each N atom; one with each ortho-Br atom. No new polytypes of 1,3,5-tribromo-2-isocyanobenzene (RNC) were found but a re-determination of the original structure by Carter et al. [(1977). Cryst. Struct. Commun. 6, 543–548] is presented. RNC was found to be isostructural with one of the novel polytypes of RCN. Unit cells were determined for 23 RCN samples and 11 RNC samples. Polytypes could not be distinguished based on crystal habits. In all four structures, each molecule of the asymmetric unit lies across a mirror plane.
Chemical context
The reported structures of 2,4,6-tribromobenzonitrile (RCN, Figs. 1 ▸ and 2 ▸; Carter & Britton, 1972 ▸) and 1,3,5-tribromo-2-isocyanobenzene (RNC, Figs. 1 ▸ and 3 ▸; Carter et al., 1977 ▸) have two-dimensional layers of similarly arranged molecules, but the packing of adjacent layers is distinctly different. At the time, no explanation was offered. It was puzzling, given that the two compounds are isoelectronic, isosteric, and the principal intermolecular interactions, C≡N⋯Br and N≡C⋯Br, are similar. Recent reports of polytype organic structures, such as picryl bromide (Parrish et al., 2008 ▸) and 5,6-dimethylbenzofurazan 1-oxide (Britton et al., 2012 ▸) led to the idea that RCN and RNC might occur as polytypes. Earlier, Bredig (1930 ▸) had determined the space group and unit cell of RCN with the same results as Carter & Britton. Bredig was trying to follow up on the goniometer studies of Jaeger (1909 ▸), but while he found the same a:b ratio as Jaeger in the RCN unit cell, he found a different b:c ratio.
Figure 1.
Synthesis of RCN and RNC.
Figure 2.
Molecular structures, with atom labeling, of RCN-I viewed along [11
]; RCN-II viewed along [120]; RCN-III viewed along [120]. Displacement ellipsoids are drawn at the 50% probability level. In discussion, molecules are named by their respective nitrogen atoms. Each molecule lies across a crystallographic mirror plane.
Figure 3.
Molecular structure, with atom labeling, of RNC-II viewed along [120]. Displacement ellipsoids are drawn at the 50% probability level. Each molecule lies across a crystallographic mirror plane.
Accordingly, a search was made for polytypes of RCN, and to a lesser extent, of RNC. Four different structures were identified. RCN-I is the original Z = 2 structure of RCN; RCN-II is a new Z = 8 polytype; RCN-III is a new Z = 12 polytype. No RNC counterparts to RCN-I or RCN-III were observed. RNC-II is the original Z = 8 structure. As the Z values suggest, RCN-II and RNC-II are isomorphs.
Structural commentary
Molecules of RCN and RNC are nearly planar. The average distance of atoms from the plane of best fit is 0.025 Å in RCN-I. For RCN-II, the average distances are 0.037 and 0.010 Å, for the (N27) and (N37) molecules, respectively. In RNC-II, the molecules are slightly more distorted, with average deviations of 0.043 and 0.017 Å for the (N127) and (N137) molecules, respectively. For RCN-III, the average distances are 0.009, 0.018, and 0.032 Å for the (N47), (N57), and (N67) molecules, respectively.
The bond lengths in RCN and RNC are generally similar (Fig. 4 ▸). They are also similar to the mean bond distances reported for bonds of each type (Allen et al., 1987 ▸). The N atom in RNC is displaced toward the aryl ring compared to the literature distances for aryl isocyanides.
Figure 4.
Selected bond lengths (Å) in RCN and RNC, averaged across all polytypes. The data shown in parentheses are the mean distances for each bond type reported by Allen et al. (1987 ▸).
Supramolecular features
Fig. 5 ▸ shows a two-dimensional layer of RCN-I. All of the structures are composed of similar layers. Adjacent molecules are associated through C≡N⋯Br interactions, arranged in 
(10) rings (Etter, 1990 ▸; Bernstein et al., 1995 ▸). The CN⋯Br distances in these rings range between 3.053 and 3.077 Å (Table 1 ▸); these distances can be compared with the N⋯Br van der Waals distance of 3.40 Å (Bondi, 1964 ▸; Rowland & Taylor, 1996 ▸). Each layer in RCN-II is composed of alternating (N27) and (N37) molecules. RCN-III contains two layers of alternating (N47) and (N57) molecules for each layer composed entirely of (N67) molecules. Adjacent pairs of layers show translational or pseudotranslational, or pseudocentric stacking (Fig. 6 ▸). RCN-I shows translational stacking between all adjacent layers (Fig. 7 ▸). In RCN-II, alternating pairs of layers show pseudocentric and pseudotranslational stacking (Fig. 8 ▸). In RCN-III, each layer of (N67) molecules pseudotranslationally overlaps both neighboring (N47/N57) layers, while pairs of adjacent (N47/N57) layers, every third pair of layers, overlap pseudocentrically (Fig. 9 ▸).
Figure 5.
View of one layer of RCN-I along [10]. Dashed blue lines represent short contacts.
Table 1. Short contact geometry (Å, °).
| X≡Y⋯Br | X≡Y | Y⋯Br | X≡Y⋯Br |
|---|---|---|---|
| C17≡N17⋯Br12i | 1.144 (10) | 3.053 (4) | 131.45 (9) |
| C27≡N27⋯Br32ii | 1.132 (7) | 3.059 (3) | 131.76 (7) |
| N127≡C127⋯Br132ii | 1.147 (6) | 3.141 (4) | 134.01 (8) |
| C37≡N37⋯Br22iii | 1.156 (6) | 3.077 (3) | 130.68 (10) |
| N137≡C137⋯Br122iii | 1.164 (6) | 3.161 (4) | 133.23 (11) |
| C47≡N47⋯Br52ii | 1.146 (6) | 3.072 (3) | 130.95 (9) |
| C57≡N57⋯Br42iii | 1.147 (6) | 3.057 (3) | 131.47 (7) |
| C67≡N67⋯Br62iv | 1.139 (6) | 3.065 (3) | 131.96 (7) |
Symmetry codes: (i) −x, 1 − y, −z; (ii) x, y, −1 + z; (iii) x, y, 1 + z; (iv) 1 − x, 1 − y, 1 − z.
Figure 6.
Pseudotranslational (T) and pseudocentric (C) stacking of layers in RCN-II and RCN-III, respectively. Both are viewed along [100]. The molecules shown are the second pair of layers from the top, in Fig. 7 ▸ and Fig. 8 ▸, respectively.
Figure 7.
Translational (T) stacking of layers in Z = 2 RCN-I, viewed along [110]. If the unit cell of RCN-I is transformed by the matrix [100/010/201], the dimensions of the projection become 10.247 (3) × 12.480 (3) Å, which is similar to the corresponding b × c measurements, 10.2147 (10) × 12.4754 (12) Å for RCN-II, and 10.2167 (18) × 12.493 (2) Å for RCN-III.
Figure 8.
Pseudocentric (C) and pseudotranslational (T) stacking of layers in Z = 8 RCN-II, viewed roughly along [010].
Figure 9.
Pseudotranslational (T) and pseudocentric (C) stacking of layers in Z = 12 RCN-III, viewed roughly along [010].
The NC⋯Br contact distances in RNC-II are a smaller percentage of the van der Waals distance, 3.63 Å, versus corresponding atoms in RCN-II. The contacts in RNC-II occur at slightly wider angles than those in RCN-II (Table 1 ▸).
In RCN-II, the planes of best fit of the two different molecules are inclined by 6.5° to each other; in RNC-II this inclination is 7.5°. In RCN-III, the relative inclination of planes of (N47) and (N57) molecules is 7.0°. These two planes are approximately bisected by the planes of (N67) molecules.
Database survey
A search of the Cambridge Structural Database (Version 5.36, update 3; Groom & Allen, 2014 ▸) for 2,4,6-trihalo-3,5-unsubstituted benzonitriles found nine entries: RCN; its trichloro analog, Gol’der et al. (1952 ▸), Carter & Britton (1972 ▸), Pink et al. (2000 ▸); its trifluoro analog, Britton (2008 ▸); four mixed-halogen entries, Gleason & Britton (1978 ▸), Britton (2005 ▸), Britton et al. (2002 ▸), and Britton (1997 ▸). Searching for the corresponding isocyanides found two entries: RNC and its trichloro analog (Pink et al., 2000 ▸).
Layers of the type observed in RCN were reported in 2,6-dibromo entries with Cl, Br, or I at the 4-position. Other entries exhibit short contacts between the cyano- or isocyano- group and one ortho-halogen atom of an intralayer molecule, with various interlayer contacts. Polymorphs are only reported for 2,4,6-trichlorobenzonitrile; those are not polytypic.
Expanding the search to include organometallic complexes found three more entries, with the cyano N or isocyano C atom ligating gallium (trifluorobenzonitrile; Tang et al., 2012 ▸), rhenium (trichloroisocyanobenzene; Ko et al., 2011 ▸), and ruthenium (RNC; Leung et al., 2009 ▸).
Synthesis and crystallization
2,4,6-Tribromoaniline was prepared from aniline according to the work of Coleman & Talbot (1943 ▸).
RCN, adapted from the work of Toya et al. (1992 ▸): Diazotization: 2,4,6-Tribromoaniline (1.25 g), water (2.5 ml), and glacial acetic acid (4.4 ml) were combined in a round-bottomed flask. The resulting suspension was cooled in an ice bath, and then H2SO4 (98%, 1.0 ml) was added dropwise, followed by an ice-cold solution of NaNO2 (520 mg) in water (4 ml). The resulting mixture was warmed to 310 K for 1 h, and then cooled in an ice bath. Cyanide suspension: CuCN (680 mg) and NaCN (1.12 g) were dissolved in water (20 ml). NaHCO3 (10.9 g) and ethyl acetate (10 ml) were added, giving a suspension, which was cooled in an ice bath. Cyanation: The diazotization mixture was added dropwise to the cyanide suspension as quickly as possible without causing excessive foaming. The ice bath was removed and then the mixture was stirred overnight. The organic phase was set aside. The aqueous phase was extracted with ethyl acetate (3 × 10 ml). The combined organic portions were washed with brine (10 ml), dried with Na2SO4, and concentrated at reduced pressure, giving a brown powder, which was purified by column chromatography (SiO2, hexane–ethyl acetate, gradient from 1:0 to 10:1). The desired fraction (Rf = 0.61 in 8:1) was concentrated at reduced pressure, giving beige needles (760 mg, 59%). M.p. 400–400.5 K (lit. 402 K; Giumanini et al., 1996 ▸); 1H NMR (300 MHz, CD2Cl2) δ 7.853 (s, H13); 13C NMR (75 MHz, CD2Cl2) δ 135.3 (C13), 128.6 (C14), 127.4 (C12), 118.3 (C17), 116.0 (C11); IR (NaCl, cm−1) 3095, 3068, 2921 (w), 2233 (s, C≡N; lit. 2232), 1716 (w), 1563 (s), 1527 (s), 1431 (s), 1410 (s), 1370 (s), 1353 (s), 1328, 1191 (s), 1109 (s), 1087, 1063 (s), 854 (s), 809 (s), 748 (s); MS (EI, m/z) [M]+ calculated for C7H2Br3N 336.7732, found 336.7716.
2,4,6-Tribromoformanilide, adapted from the work of Krishnamurthy (1982 ▸): Acetic anhydride (3.2 ml) and tetrahydrofuran (THF, 5.0 ml) were combined in a round-bottomed flask. Formic acid (88% aq., 1.7 ml) was added dropwise. The resulting solution was stirred for 30 min at room temperature. A solution of 2,4,6-tribromoaniline (1.82 g) in THF (20 ml) was added dropwise. The resulting mixture was stirred for 18 h. The resulting heterogeneous mixture was filtered through neutral alumina (Sigma–Aldrich 199974, 5 cm H × 3 cm D), with addition of sufficient THF to elute all product, as indicated by TLC. The filtrate was concentrated at reduced pressure. The resulting residue was washed with sat. NaHCO3 solution (50 ml), and then filtered. The filter cake was recrystallized from acetone, giving white needles (1.72 g, 87%). M.p. 493–494 K (lit. 494.5 K; Chattaway et al., 1899 ▸); Rf = 0.48 (SiO2 in 1:1 hexane–ethyl acetate); 1H NMR (300 MHz, (CD3)2SO) δ 10.192 (s, NH, O-E conformer, 0.87H), 8.522 (s, NH, O-Z conformer, 0.13H), 8.260 (s, CHO, 1H), 8.018 (s, CH, 2H); 13C NMR (75 MHz, (CD3)2SO) δ 165.9 (CO, O-Z conformer), 159.8 (CO, O-E conformer), 134.6 (ipso-C), 134.4 (CH), 124.5 (ortho-CBr), 121.1 (para-CBr); IR (NaCl, cm−1) 3201, 3166, 1661 (s, C=O), 1558, 1154, 858, 810; MS (ESI, m/z) [M – H]− calculated for C7H4Br3NO 355.7750, found 355.7758. Analysis (MHW Laboratories, Phoenix, AZ, USA) calculated for C7H4Br3NO: C 23.50, H 1.13, Br 66.99, N 3.91; found C 23.42, H 1.15, Br 66.71, N 3.57.
RNC, adapted from the work of Ugi et al. (1965 ▸): 2,4,6-Tribromoformanilide (1.96 g) and N,N-diisopropylethylamine (DIPEA, 3.4 ml) were added to 1,2-dichloroethane (75 ml). The resulting suspension was refluxed for 5 min, and then cooled to room temperature. POCl3 (0.6 ml) was added dropwise. The mixture was stirred for 18 h, cooled in an ice bath, and then filtered through neutral alumina (3 cm H × 3 cm D), with addition of sufficient dichloromethane (DCM) to elute all product as indicated by TLC. The filtrate was concentrated at reduced pressure. The resulting yellow residue was dissolved in DCM (25 ml), cooled in an ice bath, and washed with ice-cold acetic acid solution (0.025 M, 3 × 15 ml), and then ice-cold sat. NaHCO3 solution (15 ml). The organic phase was collected, dried with Na2SO4, and then concentrated under a stream of nitrogen, giving beige needles upon filtration (630 mg, 34%). M.p. 390 K (lit. 394 K, Mironov & Mokrushin, 1999 ▸); Rf = 0.75 (Al2O3 in 2:1 hexane–ethyl acetate); 1H NMR (300 MHz, CD2Cl2) δ 7.827 (s, H123); 13C NMR (75 MHz, (CD3)2CO) 159.7 (C127), 135.8 (C123), 135.4 (C121), 124.5 (C124), 122.0 (C122); IR (NaCl, cm−1) 3162, 3068, 2921, 2128 (s, N≡C; lit. 2125), 1660 (s), 1555 (s), 1370 (s), 856 (s), 701 (s); MS (EI, m/z) [M]+ calculated for C7H2Br3N 336.7732, found 336.7734.
Crystallization: RCN crystals were grown by slow evaporation of single-solvent solutions (290–295 K). RCN-I was obtained from acetonitrile, benzene, chloroform, or methylene chloride; RCN-II from mesitylene; RCN-III from benzene or chloroform. RNC-II crystals were obtained by sublimation (385 K, 0.05 torr), or by slow evaporation from the same solvents as RCN (268–295 K).
Refinement
Crystal data, data collection, and structure refinement details for RCN and RNC are summarized in Table 2 ▸. H atoms were placed in calculated positions and refined as riding atoms, with C—H = 0.95 Å and U iso(H) = 1.2U eq(C).
Table 2. Experimental details.
| RCN-I | RCN-II | RCN-III | RNC-II | |
|---|---|---|---|---|
| Crystal data | ||||
| Chemical formula | C7H2Br3N | C7H2Br3N | C7H2Br3N | C7H2Br3N |
| M r | 339.83 | 339.83 | 339.83 | 339.83 |
| Crystal system, space group | Monoclinic, P21/m | Orthorhombic, P n m a | Orthorhombic, P n m a | Orthorhombic, P n m a |
| Temperature (K) | 173 | 173 | 173 | 173 |
| a, b, c (Å) | 4.8742 (15), 10.247 (3), 8.683 (3) | 13.6183 (13), 10.2147 (10), 12.4754 (12) | 20.399 (4), 10.2167 (18), 12.493 (2) | 13.5916 (18), 10.1464 (13), 12.6158 (16) |
| α, β, γ (°) | 90, 94.97 (1), 90 | 90, 90, 90 | 90, 90, 90 | 90, 90, 90 |
| V (Å3) | 432.0 (2) | 1735.4 (3) | 2603.7 (8) | 1739.8 (4) |
| Z | 2 | 8 | 12 | 8 |
| Radiation type | Mo Kα | Mo Kα | Mo Kα | Mo Kα |
| μ (mm−1) | 13.93 | 13.88 | 13.87 | 13.84 |
| Crystal size (mm) | 0.50 × 0.15 × 0.10 | 0.25 × 0.20 × 0.07 | 0.50 × 0.15 × 0.10 | 0.40 × 0.35 × 0.20 |
| Data collection | ||||
| Diffractometer | Bruker 1K area detector | Bruker 1K area detector | Bruker 1K area detector | Bruker APEXII CCD |
| Absorption correction | Multi-scan (SADABS; Bruker, 2002 ▸) | Multi-scan (SADABS; Bruker, 2002 ▸) | Multi-scan (SADABS; Bruker, 2002 ▸) | Multi-scan (SADABS; Bruker, 2002 ▸) |
| T min, T max | 0.080, 0.248 | 0.06, 0.37 | 0.054, 0.337 | 0.170, 0.333 |
| No. of measured, independent and observed [I > 2σ(I)] reflections | 4093, 1024, 856 | 16607, 2093, 1692 | 22804, 2691, 2165 | 19459, 2105, 1638 |
| R int | 0.127 | 0.052 | 0.055 | 0.078 |
| (sin θ/λ)max (Å−1) | 0.649 | 0.650 | 0.616 | 0.650 |
| Refinement | ||||
| R[F 2 > 2σ(F 2)], wR(F 2), S | 0.046, 0.116, 1.01 | 0.028, 0.063, 1.02 | 0.023, 0.046, 1.07 | 0.025, 0.055, 1.06 |
| No. of reflections | 1024 | 2093 | 2691 | 2105 |
| No. of parameters | 58 | 115 | 173 | 116 |
| H-atom treatment | H-atom parameters constrained | H-atom parameters constrained | H-atom parameters constrained | H-atom parameters constrained |
| Δρmax, Δρmin (e Å−3) | 1.36, −1.28 | 0.44, −0.69 | 0.56, −0.49 | 0.44, −0.48 |
Supplementary Material
Crystal structure: contains datablock(s) global, RCN-I, RCN-II, RCN-III, RNC-II. DOI: 10.1107/S2056989016000256/lh5796sup1.cif
Structure factors: contains datablock(s) RCN-I. DOI: 10.1107/S2056989016000256/lh5796RCN-Isup2.hkl
Supporting information file. DOI: 10.1107/S2056989016000256/lh5796RCN-Isup6.cml
Structure factors: contains datablock(s) RCN-II. DOI: 10.1107/S2056989016000256/lh5796RCN-IIsup3.hkl
Structure factors: contains datablock(s) RCN-III. DOI: 10.1107/S2056989016000256/lh5796RCN-IIIsup4.hkl
Structure factors: contains datablock(s) RNC-II. DOI: 10.1107/S2056989016000256/lh5796RNC-IIsup5.hkl
Additional supporting information: crystallographic information; 3D view; checkCIF report
Acknowledgments
The authors thank Victor G. Young, Jr. (X-Ray Crystallographic Laboratory, University of Minnesota) for assistance with unit cell and crystal determinations, and the Wayland E. Noland Research Fellowship Fund at the University of Minnesota Foundation for generous financial support of this project.
supplementary crystallographic information
(RCN-I) 2,4,6-Tribromobenzonitrile - polytype I. Crystal data
| C7H2Br3N | F(000) = 312 |
| Mr = 339.83 | Dx = 2.612 Mg m−3 |
| Monoclinic, P21/m | Mo Kα radiation, λ = 0.71073 Å |
| Hall symbol: -P 2yb | Cell parameters from 2049 reflections |
| a = 4.8742 (15) Å | θ = 2.4–27.4° |
| b = 10.247 (3) Å | µ = 13.93 mm−1 |
| c = 8.683 (3) Å | T = 173 K |
| β = 94.97 (1)° | Needle, colorless |
| V = 432.0 (2) Å3 | 0.50 × 0.15 × 0.10 mm |
| Z = 2 |
(RCN-I) 2,4,6-Tribromobenzonitrile - polytype I. Data collection
| Bruker 1K area-detector diffractometer | 1024 independent reflections |
| Radiation source: fine-focus sealed tube | 856 reflections with I > 2σ(I) |
| Graphite monochromator | Rint = 0.127 |
| ω scans | θmax = 27.5°, θmin = 2.4° |
| Absorption correction: multi-scan (SADABS; Bruker, 2002) | h = −6→6 |
| Tmin = 0.080, Tmax = 0.248 | k = −13→13 |
| 4093 measured reflections | l = −11→11 |
(RCN-I) 2,4,6-Tribromobenzonitrile - polytype I. Refinement
| Refinement on F2 | Primary atom site location: structure-invariant direct methods |
| Least-squares matrix: full | Secondary atom site location: difference Fourier map |
| R[F2 > 2σ(F2)] = 0.046 | Hydrogen site location: inferred from neighbouring sites |
| wR(F2) = 0.116 | H-atom parameters constrained |
| S = 1.01 | w = 1/[σ2(Fo2) + (0.069P)2] where P = (Fo2 + 2Fc2)/3 |
| 1024 reflections | (Δ/σ)max = 0.001 |
| 58 parameters | Δρmax = 1.36 e Å−3 |
| 0 restraints | Δρmin = −1.28 e Å−3 |
(RCN-I) 2,4,6-Tribromobenzonitrile - polytype I. Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2)
| x | y | z | Uiso*/Ueq | ||
| Br12 | 0.33356 (11) | 0.47324 (5) | 0.18676 (7) | 0.0280 (2) | |
| Br14 | 1.11323 (14) | 0.7500 | 0.57820 (9) | 0.0256 (3) | |
| N17 | −0.0263 (14) | 0.7500 | −0.0147 (8) | 0.0313 (16) | |
| C11 | 0.3828 (14) | 0.7500 | 0.1960 (8) | 0.0204 (15) | |
| C12 | 0.4932 (10) | 0.6324 (5) | 0.2559 (6) | 0.0224 (11) | |
| C13 | 0.7107 (10) | 0.6313 (5) | 0.3688 (6) | 0.0244 (11) | |
| H13 | 0.7842 | 0.5512 | 0.4091 | 0.029* | |
| C14 | 0.8200 (14) | 0.7500 | 0.4224 (8) | 0.0197 (15) | |
| C17 | 0.1523 (16) | 0.7500 | 0.0799 (9) | 0.0241 (16) |
(RCN-I) 2,4,6-Tribromobenzonitrile - polytype I. Atomic displacement parameters (Å2)
| U11 | U22 | U33 | U12 | U13 | U23 | |
| Br12 | 0.0334 (4) | 0.0160 (3) | 0.0337 (4) | −0.0043 (2) | −0.0015 (2) | −0.0016 (2) |
| Br14 | 0.0229 (4) | 0.0239 (4) | 0.0295 (5) | 0.000 | −0.0018 (3) | 0.000 |
| N17 | 0.041 (4) | 0.021 (3) | 0.031 (4) | 0.000 | −0.006 (3) | 0.000 |
| C11 | 0.022 (3) | 0.025 (4) | 0.015 (4) | 0.000 | 0.005 (3) | 0.000 |
| C12 | 0.023 (2) | 0.016 (2) | 0.029 (3) | −0.0012 (19) | 0.006 (2) | 0.001 (2) |
| C13 | 0.024 (2) | 0.017 (3) | 0.033 (3) | 0.004 (2) | 0.007 (2) | 0.004 (2) |
| C14 | 0.024 (3) | 0.025 (4) | 0.011 (3) | 0.000 | 0.003 (3) | 0.000 |
| C17 | 0.030 (4) | 0.011 (3) | 0.032 (4) | 0.000 | 0.004 (3) | 0.000 |
(RCN-I) 2,4,6-Tribromobenzonitrile - polytype I. Geometric parameters (Å, º)
| Br12—C12 | 1.883 (5) | C12—C13 | 1.380 (8) |
| Br14—C14 | 1.881 (7) | C13—C14 | 1.391 (6) |
| C11—C12 | 1.401 (6) | C13—H13 | 0.9500 |
| C11—C17 | 1.443 (10) | N17—C17 | 1.144 (10) |
| C12—C11—C12i | 118.6 (6) | C12—C13—H13 | 120.7 |
| C12—C11—C17 | 120.7 (3) | C14—C13—H13 | 120.7 |
| C13—C12—C11 | 121.2 (5) | C13—C14—C13i | 121.9 (6) |
| C13—C12—Br12 | 119.3 (4) | C13—C14—Br14 | 119.0 (3) |
| C11—C12—Br12 | 119.4 (4) | N17—C17—C11 | 178.4 (9) |
| C12—C13—C14 | 118.6 (5) | ||
| C12i—C11—C12—C13 | −1.6 (11) | C11—C12—C13—C14 | −0.2 (10) |
| C17—C11—C12—C13 | −178.9 (7) | Br12—C12—C13—C14 | −177.8 (5) |
| C12i—C11—C12—Br12 | 176.0 (3) | C12—C13—C14—C13i | 2.0 (12) |
| C17—C11—C12—Br12 | −1.3 (9) | C12—C13—C14—Br14 | 179.2 (5) |
Symmetry code: (i) x, −y+3/2, z.
(RCN-II) 2,4,6-Tribromobenzonitrile - polytype II. Crystal data
| C7H2Br3N | F(000) = 1248 |
| Mr = 339.83 | Dx = 2.601 Mg m−3 |
| Orthorhombic, Pnma | Mo Kα radiation, λ = 0.71073 Å |
| Hall symbol: -P 2ac 2n | Cell parameters from 3180 reflections |
| a = 13.6183 (13) Å | θ = 2.9–27.2° |
| b = 10.2147 (10) Å | µ = 13.88 mm−1 |
| c = 12.4754 (12) Å | T = 173 K |
| V = 1735.4 (3) Å3 | Plate, colorless |
| Z = 8 | 0.25 × 0.20 × 0.07 mm |
(RCN-II) 2,4,6-Tribromobenzonitrile - polytype II. Data collection
| Bruker 1K area-detector diffractometer | 2093 independent reflections |
| Radiation source: fine-focus sealed tube | 1692 reflections with I > 2σ(I) |
| Graphite monochromator | Rint = 0.052 |
| ω scans | θmax = 27.5°, θmin = 2.2° |
| Absorption correction: multi-scan (SADABS; Bruker, 2002) | h = −17→17 |
| Tmin = 0.06, Tmax = 0.37 | k = −13→13 |
| 16607 measured reflections | l = −16→16 |
(RCN-II) 2,4,6-Tribromobenzonitrile - polytype II. Refinement
| Refinement on F2 | Primary atom site location: structure-invariant direct methods |
| Least-squares matrix: full | Secondary atom site location: difference Fourier map |
| R[F2 > 2σ(F2)] = 0.028 | Hydrogen site location: inferred from neighbouring sites |
| wR(F2) = 0.063 | H-atom parameters constrained |
| S = 1.02 | w = 1/[σ2(Fo2) + (0.030P)2 + 1.560P] where P = (Fo2 + 2Fc2)/3 |
| 2093 reflections | (Δ/σ)max = 0.001 |
| 115 parameters | Δρmax = 0.44 e Å−3 |
| 0 restraints | Δρmin = −0.69 e Å−3 |
(RCN-II) 2,4,6-Tribromobenzonitrile - polytype II. Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2)
| x | y | z | Uiso*/Ueq | ||
| Br22 | 0.13341 (3) | 0.52761 (3) | 0.04244 (3) | 0.02658 (11) | |
| Br24 | 0.14558 (4) | 0.2500 | 0.43375 (4) | 0.02477 (13) | |
| C21 | 0.1318 (3) | 0.2500 | 0.0608 (4) | 0.0197 (10) | |
| C22 | 0.1359 (2) | 0.3683 (3) | 0.1174 (3) | 0.0206 (7) | |
| C23 | 0.1418 (2) | 0.3697 (3) | 0.2282 (3) | 0.0217 (7) | |
| H23 | 0.1444 | 0.4500 | 0.2666 | 0.026* | |
| C24 | 0.1437 (3) | 0.2500 | 0.2821 (4) | 0.0190 (10) | |
| C27 | 0.1207 (4) | 0.2500 | −0.0545 (4) | 0.0257 (11) | |
| N27 | 0.1115 (3) | 0.2500 | −0.1447 (4) | 0.0332 (11) | |
| Br32 | 0.10699 (3) | 0.47273 (3) | 0.69146 (3) | 0.02650 (11) | |
| Br34 | 0.12804 (4) | 0.7500 | 0.29979 (4) | 0.02786 (13) | |
| C31 | 0.1095 (3) | 0.7500 | 0.6720 (3) | 0.0175 (9) | |
| C32 | 0.1116 (2) | 0.6320 (3) | 0.6155 (3) | 0.0195 (7) | |
| C33 | 0.1171 (2) | 0.6315 (3) | 0.5049 (3) | 0.0201 (7) | |
| H33 | 0.1189 | 0.5511 | 0.4666 | 0.024* | |
| C34 | 0.1199 (3) | 0.7500 | 0.4508 (4) | 0.0196 (10) | |
| C37 | 0.1056 (3) | 0.7500 | 0.7873 (4) | 0.0200 (10) | |
| N37 | 0.1015 (3) | 0.7500 | 0.8798 (3) | 0.0255 (9) |
(RCN-II) 2,4,6-Tribromobenzonitrile - polytype II. Atomic displacement parameters (Å2)
| U11 | U22 | U33 | U12 | U13 | U23 | |
| Br22 | 0.0364 (2) | 0.01742 (19) | 0.0259 (2) | −0.00058 (15) | −0.00196 (15) | 0.00451 (14) |
| Br24 | 0.0303 (3) | 0.0261 (3) | 0.0179 (2) | 0.000 | 0.00098 (19) | 0.000 |
| C21 | 0.018 (2) | 0.021 (3) | 0.021 (2) | 0.000 | 0.0017 (19) | 0.000 |
| C22 | 0.0208 (16) | 0.0182 (16) | 0.0227 (17) | 0.0016 (14) | −0.0003 (13) | 0.0017 (14) |
| C23 | 0.0225 (16) | 0.0186 (18) | 0.0240 (17) | −0.0012 (14) | −0.0012 (14) | −0.0017 (14) |
| C24 | 0.021 (2) | 0.021 (3) | 0.015 (2) | 0.000 | 0.0022 (18) | 0.000 |
| C27 | 0.028 (3) | 0.020 (3) | 0.029 (3) | 0.000 | 0.000 (2) | 0.000 |
| N27 | 0.048 (3) | 0.026 (2) | 0.026 (3) | 0.000 | −0.002 (2) | 0.000 |
| Br32 | 0.0386 (2) | 0.01618 (19) | 0.02475 (19) | −0.00117 (15) | 0.00205 (14) | 0.00374 (14) |
| Br34 | 0.0418 (3) | 0.0243 (3) | 0.0174 (2) | 0.000 | −0.0003 (2) | 0.000 |
| C31 | 0.017 (2) | 0.021 (2) | 0.015 (2) | 0.000 | −0.0003 (17) | 0.000 |
| C32 | 0.0182 (15) | 0.0163 (16) | 0.0241 (17) | 0.0004 (13) | −0.0006 (13) | 0.0044 (14) |
| C33 | 0.0229 (17) | 0.0157 (18) | 0.0216 (17) | 0.0015 (14) | −0.0009 (13) | −0.0018 (14) |
| C34 | 0.025 (2) | 0.018 (2) | 0.015 (2) | 0.000 | −0.0001 (18) | 0.000 |
| C37 | 0.023 (2) | 0.014 (2) | 0.023 (3) | 0.000 | −0.0009 (19) | 0.000 |
| N37 | 0.030 (2) | 0.024 (2) | 0.023 (2) | 0.000 | −0.0002 (17) | 0.000 |
(RCN-II) 2,4,6-Tribromobenzonitrile - polytype II. Geometric parameters (Å, º)
| Br22—C22 | 1.877 (3) | Br32—C32 | 1.884 (3) |
| Br24—C24 | 1.892 (5) | Br34—C34 | 1.887 (4) |
| C21—C22 | 1.400 (4) | C31—C32 | 1.396 (4) |
| C21—C27 | 1.446 (7) | C31—C37 | 1.439 (6) |
| C22—C23 | 1.385 (5) | C32—C33 | 1.382 (5) |
| C23—C24 | 1.395 (4) | C33—C34 | 1.387 (4) |
| C23—H23 | 0.9500 | C33—H33 | 0.9500 |
| C27—N27 | 1.132 (7) | C37—N37 | 1.156 (6) |
| C22i—C21—C22 | 119.3 (4) | C32ii—C31—C32 | 119.3 (4) |
| C22—C21—C27 | 120.3 (2) | C32—C31—C37 | 120.3 (2) |
| C23—C22—C21 | 120.9 (3) | C33—C32—C31 | 120.6 (3) |
| C23—C22—Br22 | 119.3 (3) | C33—C32—Br32 | 120.0 (3) |
| C21—C22—Br22 | 119.8 (3) | C31—C32—Br32 | 119.4 (2) |
| C22—C23—C24 | 118.2 (3) | C32—C33—C34 | 118.9 (3) |
| C22—C23—H23 | 120.9 | C32—C33—H33 | 120.5 |
| C24—C23—H23 | 120.9 | C34—C33—H33 | 120.5 |
| C23i—C24—C23 | 122.4 (4) | C33ii—C34—C33 | 121.6 (4) |
| C23—C24—Br24 | 118.8 (2) | C33—C34—Br34 | 119.2 (2) |
| N27—C27—C21 | 179.7 (5) | N37—C37—C31 | 179.3 (5) |
| C22i—C21—C22—C23 | −1.4 (6) | C32ii—C31—C32—C33 | 0.8 (6) |
| C27—C21—C22—C23 | 176.8 (4) | C37—C31—C32—C33 | −178.9 (4) |
| C22i—C21—C22—Br22 | 178.6 (2) | C32ii—C31—C32—Br32 | −179.2 (2) |
| C27—C21—C22—Br22 | −3.2 (5) | C37—C31—C32—Br32 | 1.1 (5) |
| C21—C22—C23—C24 | 0.1 (5) | C31—C32—C33—C34 | −0.3 (5) |
| Br22—C22—C23—C24 | −179.9 (3) | Br32—C32—C33—C34 | 179.7 (3) |
| C22—C23—C24—C23i | 1.3 (7) | C32—C33—C34—C33ii | −0.2 (7) |
| C22—C23—C24—Br24 | −177.1 (2) | C32—C33—C34—Br34 | 179.7 (2) |
Symmetry codes: (i) x, −y+1/2, z; (ii) x, −y+3/2, z.
(RCN-III) 2,4,6-Tribromobenzonitrile - polytype III. Crystal data
| C7H2Br3N | F(000) = 1872 |
| Mr = 339.83 | Dx = 2.601 Mg m−3 |
| Orthorhombic, Pnma | Mo Kα radiation, λ = 0.71073 Å |
| Hall symbol: -P 2ac 2n | Cell parameters from 2928 reflections |
| a = 20.399 (4) Å | θ = 2.6–26.7° |
| b = 10.2167 (18) Å | µ = 13.87 mm−1 |
| c = 12.493 (2) Å | T = 173 K |
| V = 2603.7 (8) Å3 | Needle, colorless |
| Z = 12 | 0.50 × 0.15 × 0.10 mm |
(RCN-III) 2,4,6-Tribromobenzonitrile - polytype III. Data collection
| Bruker 1K area-detector diffractometer | 2691 independent reflections |
| Radiation source: fine-focus sealed tube | 2165 reflections with I > 2σ(I) |
| Graphite monochromator | Rint = 0.055 |
| ω scans | θmax = 26.0°, θmin = 2.6° |
| Absorption correction: multi-scan (SADABS; Bruker, 2002) | h = −24→24 |
| Tmin = 0.054, Tmax = 0.337 | k = −12→12 |
| 22804 measured reflections | l = −15→15 |
(RCN-III) 2,4,6-Tribromobenzonitrile - polytype III. Refinement
| Refinement on F2 | Secondary atom site location: difference Fourier map |
| Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
| R[F2 > 2σ(F2)] = 0.023 | H-atom parameters constrained |
| wR(F2) = 0.046 | w = 1/[σ2(Fo2) + (0.0096P)2 + 3.390P] where P = (Fo2 + 2Fc2)/3 |
| S = 1.07 | (Δ/σ)max = 0.001 |
| 2691 reflections | Δρmax = 0.56 e Å−3 |
| 173 parameters | Δρmin = −0.49 e Å−3 |
| 0 restraints | Extinction correction: SHELXL, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
| Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.00028 (3) |
(RCN-III) 2,4,6-Tribromobenzonitrile - polytype III. Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2)
| x | y | z | Uiso*/Ueq | ||
| Br42 | 0.340999 (16) | 0.52705 (3) | −0.05464 (3) | 0.02707 (10) | |
| Br44 | 0.32895 (2) | 0.2500 | 0.33679 (4) | 0.02913 (13) | |
| Br52 | 0.332551 (16) | 0.47245 (3) | 0.59427 (3) | 0.02775 (9) | |
| Br54 | 0.32011 (2) | 0.7500 | 0.20370 (3) | 0.02542 (12) | |
| Br62 | 0.511839 (16) | 0.52774 (3) | 0.67598 (3) | 0.02743 (10) | |
| Br64 | 0.50730 (2) | 0.2500 | 1.06666 (4) | 0.02435 (12) | |
| C41 | 0.33919 (19) | 0.2500 | −0.0353 (3) | 0.0182 (9) | |
| C42 | 0.33772 (14) | 0.3675 (3) | 0.0214 (2) | 0.0207 (7) | |
| C43 | 0.33432 (14) | 0.3686 (3) | 0.1321 (2) | 0.0226 (7) | |
| H43 | 0.3331 | 0.4487 | 0.1706 | 0.027* | |
| C44 | 0.3328 (2) | 0.2500 | 0.1851 (4) | 0.0219 (10) | |
| C47 | 0.3440 (2) | 0.2500 | −0.1508 (4) | 0.0218 (10) | |
| N47 | 0.34814 (18) | 0.2500 | −0.2423 (3) | 0.0272 (9) | |
| C51 | 0.3338 (2) | 0.7500 | 0.5758 (4) | 0.0221 (10) | |
| C52 | 0.33096 (14) | 0.6320 (3) | 0.5193 (2) | 0.0211 (7) | |
| C53 | 0.32641 (14) | 0.6314 (3) | 0.4085 (2) | 0.0228 (7) | |
| H53 | 0.3246 | 0.5512 | 0.3701 | 0.027* | |
| C54 | 0.3245 (2) | 0.7500 | 0.3549 (3) | 0.0204 (10) | |
| C57 | 0.3399 (2) | 0.7500 | 0.6908 (4) | 0.0225 (10) | |
| N57 | 0.3445 (2) | 0.7500 | 0.7823 (3) | 0.0329 (10) | |
| C61 | 0.5080 (2) | 0.2500 | 0.6942 (4) | 0.0204 (10) | |
| C62 | 0.50889 (14) | 0.3676 (3) | 0.7509 (2) | 0.0216 (7) | |
| C63 | 0.50886 (14) | 0.3686 (3) | 0.8618 (2) | 0.0218 (7) | |
| H63 | 0.5092 | 0.4488 | 0.9002 | 0.026* | |
| C64 | 0.5083 (2) | 0.2500 | 0.9155 (4) | 0.0200 (10) | |
| C67 | 0.5049 (2) | 0.2500 | 0.5783 (4) | 0.0225 (10) | |
| N67 | 0.5024 (2) | 0.2500 | 0.4872 (3) | 0.0329 (10) |
(RCN-III) 2,4,6-Tribromobenzonitrile - polytype III. Atomic displacement parameters (Å2)
| U11 | U22 | U33 | U12 | U13 | U23 | |
| Br42 | 0.03864 (19) | 0.01711 (17) | 0.02545 (18) | −0.00178 (14) | 0.00143 (15) | 0.00391 (15) |
| Br44 | 0.0432 (3) | 0.0252 (3) | 0.0190 (3) | 0.000 | 0.0007 (2) | 0.000 |
| Br52 | 0.03826 (19) | 0.01818 (17) | 0.02682 (18) | −0.00040 (15) | −0.00267 (15) | 0.00467 (15) |
| Br54 | 0.0309 (3) | 0.0270 (3) | 0.0184 (2) | 0.000 | 0.0017 (2) | 0.000 |
| Br62 | 0.03877 (19) | 0.01736 (17) | 0.02617 (18) | −0.00080 (15) | −0.00036 (15) | 0.00376 (15) |
| Br64 | 0.0300 (2) | 0.0243 (3) | 0.0188 (2) | 0.000 | −0.00018 (19) | 0.000 |
| C41 | 0.016 (2) | 0.017 (2) | 0.022 (2) | 0.000 | −0.0010 (18) | 0.000 |
| C42 | 0.0214 (15) | 0.0175 (17) | 0.0233 (17) | −0.0001 (14) | −0.0011 (13) | 0.0052 (14) |
| C43 | 0.0269 (16) | 0.0160 (17) | 0.0248 (17) | −0.0016 (14) | −0.0003 (14) | −0.0016 (15) |
| C44 | 0.023 (2) | 0.024 (3) | 0.019 (2) | 0.000 | 0.0000 (19) | 0.000 |
| C47 | 0.020 (2) | 0.016 (2) | 0.029 (3) | 0.000 | −0.004 (2) | 0.000 |
| N47 | 0.033 (2) | 0.022 (2) | 0.026 (2) | 0.000 | −0.0017 (19) | 0.000 |
| C51 | 0.016 (2) | 0.026 (3) | 0.024 (2) | 0.000 | 0.001 (2) | 0.000 |
| C52 | 0.0244 (15) | 0.0154 (17) | 0.0234 (16) | 0.0002 (14) | −0.0002 (13) | 0.0037 (14) |
| C53 | 0.0255 (16) | 0.0198 (18) | 0.0232 (17) | 0.0025 (14) | 0.0024 (14) | −0.0031 (15) |
| C54 | 0.020 (2) | 0.024 (3) | 0.017 (2) | 0.000 | 0.0021 (18) | 0.000 |
| C57 | 0.025 (2) | 0.015 (2) | 0.027 (3) | 0.000 | −0.003 (2) | 0.000 |
| N57 | 0.048 (3) | 0.027 (2) | 0.024 (2) | 0.000 | −0.001 (2) | 0.000 |
| C61 | 0.020 (2) | 0.022 (2) | 0.020 (2) | 0.000 | 0.0041 (19) | 0.000 |
| C62 | 0.0199 (15) | 0.0188 (17) | 0.0261 (17) | 0.0017 (13) | 0.0011 (13) | 0.0047 (15) |
| C63 | 0.0236 (16) | 0.0178 (18) | 0.0239 (16) | 0.0007 (14) | 0.0018 (13) | −0.0028 (15) |
| C64 | 0.020 (2) | 0.022 (2) | 0.018 (2) | 0.000 | 0.0017 (19) | 0.000 |
| C67 | 0.028 (2) | 0.016 (2) | 0.024 (3) | 0.000 | 0.000 (2) | 0.000 |
| N67 | 0.055 (3) | 0.021 (2) | 0.024 (2) | 0.000 | −0.002 (2) | 0.000 |
(RCN-III) 2,4,6-Tribromobenzonitrile - polytype III. Geometric parameters (Å, º)
| Br42—C42 | 1.888 (3) | C51—C52 | 1.399 (4) |
| Br44—C44 | 1.897 (5) | C51—C57 | 1.443 (6) |
| Br52—C52 | 1.880 (3) | C52—C53 | 1.387 (4) |
| Br54—C54 | 1.892 (4) | C53—C54 | 1.384 (4) |
| Br62—C62 | 1.885 (3) | C53—H53 | 0.9500 |
| Br64—C64 | 1.889 (4) | C57—N57 | 1.147 (6) |
| C41—C42 | 1.394 (4) | C61—C62 | 1.395 (4) |
| C41—C47 | 1.447 (6) | C61—C67 | 1.450 (6) |
| C42—C43 | 1.384 (4) | C62—C63 | 1.386 (4) |
| C43—C44 | 1.381 (4) | C63—C64 | 1.385 (4) |
| C43—H43 | 0.9500 | C63—H63 | 0.9500 |
| C47—N47 | 1.146 (6) | C67—N67 | 1.139 (6) |
| C42—C41—C42i | 118.9 (4) | C54—C53—H53 | 120.6 |
| C42—C41—C47 | 120.5 (2) | C52—C53—H53 | 120.6 |
| C43—C42—C41 | 121.0 (3) | C53ii—C54—C53 | 122.1 (4) |
| C43—C42—Br42 | 119.9 (2) | C53—C54—Br54 | 119.0 (2) |
| C41—C42—Br42 | 119.2 (2) | N57—C57—C51 | 179.8 (5) |
| C44—C43—C42 | 118.3 (3) | C62i—C61—C62 | 119.0 (4) |
| C44—C43—H43 | 120.9 | C62—C61—C67 | 120.5 (2) |
| C42—C43—H43 | 120.9 | C63—C62—C61 | 120.9 (3) |
| C43i—C44—C43 | 122.6 (4) | C63—C62—Br62 | 119.4 (3) |
| C43—C44—Br44 | 118.7 (2) | C61—C62—Br62 | 119.8 (2) |
| N47—C47—C41 | 179.7 (5) | C64—C63—C62 | 118.6 (3) |
| C52ii—C51—C52 | 119.1 (4) | C64—C63—H63 | 120.7 |
| C52—C51—C57 | 120.4 (2) | C62—C63—H63 | 120.7 |
| C53—C52—C51 | 120.7 (3) | C63i—C64—C63 | 122.0 (4) |
| C53—C52—Br52 | 119.7 (2) | C63—C64—Br64 | 119.0 (2) |
| C51—C52—Br52 | 119.7 (2) | N67—C67—C61 | 180.0 (5) |
| C54—C53—C52 | 118.7 (3) | ||
| C42i—C41—C42—C43 | −0.5 (6) | C51—C52—C53—C54 | −0.2 (5) |
| C47—C41—C42—C43 | −178.8 (3) | Br52—C52—C53—C54 | 179.2 (3) |
| C42i—C41—C42—Br42 | 179.07 (19) | C52—C53—C54—C53ii | −0.6 (6) |
| C47—C41—C42—Br42 | 0.8 (5) | C52—C53—C54—Br54 | 178.7 (2) |
| C41—C42—C43—C44 | 0.4 (5) | C62i—C61—C62—C63 | −1.7 (6) |
| Br42—C42—C43—C44 | −179.2 (3) | C67—C61—C62—C63 | 177.0 (3) |
| C42—C43—C44—C43i | −0.2 (6) | C62i—C61—C62—Br62 | 177.1 (2) |
| C42—C43—C44—Br44 | 179.4 (2) | C67—C61—C62—Br62 | −4.2 (5) |
| C52ii—C51—C52—C53 | 0.9 (6) | C61—C62—C63—C64 | 0.4 (5) |
| C57—C51—C52—C53 | −178.7 (3) | Br62—C62—C63—C64 | −178.4 (3) |
| C52ii—C51—C52—Br52 | −178.48 (19) | C62—C63—C64—C63i | 1.0 (6) |
| C57—C51—C52—Br52 | 1.9 (5) | C62—C63—C64—Br64 | −179.3 (2) |
Symmetry codes: (i) x, −y+1/2, z; (ii) x, −y+3/2, z.
(RNC-II) 1,3,5-Tribromo-2-isocyanobenzene - polytype II. Crystal data
| C7H2Br3N | Dx = 2.595 Mg m−3 |
| Mr = 339.83 | Mo Kα radiation, λ = 0.71073 Å |
| Orthorhombic, Pnma | Cell parameters from 2721 reflections |
| a = 13.5916 (18) Å | θ = 3.0–27.4° |
| b = 10.1464 (13) Å | µ = 13.84 mm−1 |
| c = 12.6158 (16) Å | T = 173 K |
| V = 1739.8 (4) Å3 | Block, colourless |
| Z = 8 | 0.40 × 0.35 × 0.20 mm |
| F(000) = 1248 |
(RNC-II) 1,3,5-Tribromo-2-isocyanobenzene - polytype II. Data collection
| Bruker APEXII CCD diffractometer | 1638 reflections with I > 2σ(I) |
| Radiation source: sealed tube | Rint = 0.078 |
| φ and ω scans | θmax = 27.5°, θmin = 2.2° |
| Absorption correction: multi-scan (SADABS; Bruker, 2002) | h = −17→17 |
| Tmin = 0.170, Tmax = 0.333 | k = −13→13 |
| 19459 measured reflections | l = −16→16 |
| 2105 independent reflections |
(RNC-II) 1,3,5-Tribromo-2-isocyanobenzene - polytype II. Refinement
| Refinement on F2 | Hydrogen site location: inferred from neighbouring sites |
| Least-squares matrix: full | H-atom parameters constrained |
| R[F2 > 2σ(F2)] = 0.025 | w = 1/[σ2(Fo2) + (0.0121P)2 + 1.0004P] where P = (Fo2 + 2Fc2)/3 |
| wR(F2) = 0.055 | (Δ/σ)max = 0.001 |
| S = 1.06 | Δρmax = 0.44 e Å−3 |
| 2105 reflections | Δρmin = −0.48 e Å−3 |
| 116 parameters | Extinction correction: SHELXL, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
| 0 restraints | Extinction coefficient: 0.00269 (12) |
(RNC-II) 1,3,5-Tribromo-2-isocyanobenzene - polytype II. Special details
| 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. |
(RNC-II) 1,3,5-Tribromo-2-isocyanobenzene - polytype II. Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2)
| x | y | z | Uiso*/Ueq | ||
| C121 | 0.3678 (3) | 0.7500 | 0.5680 (3) | 0.0162 (9) | |
| C122 | 0.3637 (2) | 0.6315 (3) | 0.6238 (2) | 0.0176 (7) | |
| C123 | 0.3573 (2) | 0.6306 (3) | 0.7332 (2) | 0.0182 (7) | |
| H123 | 0.3541 | 0.5499 | 0.7712 | 0.022* | |
| C124 | 0.3559 (3) | 0.7500 | 0.7858 (4) | 0.0173 (9) | |
| N127 | 0.3793 (3) | 0.7500 | 0.4583 (3) | 0.0215 (9) | |
| C127 | 0.3909 (4) | 0.7500 | 0.3682 (4) | 0.0285 (12) | |
| Br122 | 0.36763 (3) | 0.47074 (3) | 0.54952 (3) | 0.02456 (11) | |
| Br124 | 0.35282 (4) | 0.7500 | 0.93610 (4) | 0.02254 (13) | |
| C131 | 0.3904 (3) | 0.2500 | 0.1747 (3) | 0.0161 (10) | |
| C132 | 0.3885 (2) | 0.3685 (3) | 0.1192 (3) | 0.0169 (7) | |
| C133 | 0.3821 (2) | 0.3691 (3) | 0.0100 (2) | 0.0179 (7) | |
| H133 | 0.3806 | 0.4499 | −0.0281 | 0.021* | |
| C134 | 0.3781 (3) | 0.2500 | −0.0428 (4) | 0.0190 (10) | |
| N137 | 0.3955 (3) | 0.2500 | 0.2840 (3) | 0.0180 (8) | |
| C137 | 0.3995 (3) | 0.2500 | 0.3761 (4) | 0.0246 (11) | |
| Br132 | 0.39399 (3) | 0.52885 (3) | 0.19404 (3) | 0.02480 (11) | |
| Br134 | 0.36801 (4) | 0.2500 | −0.19267 (4) | 0.02564 (14) |
(RNC-II) 1,3,5-Tribromo-2-isocyanobenzene - polytype II. Atomic displacement parameters (Å2)
| U11 | U22 | U33 | U12 | U13 | U23 | |
| C121 | 0.013 (2) | 0.019 (2) | 0.016 (2) | 0.000 | 0.0002 (19) | 0.000 |
| C122 | 0.0164 (16) | 0.0157 (16) | 0.0207 (17) | 0.0016 (14) | −0.0016 (14) | −0.0031 (13) |
| C123 | 0.0191 (17) | 0.0152 (17) | 0.0202 (17) | 0.0013 (14) | −0.0017 (14) | 0.0039 (13) |
| C124 | 0.017 (2) | 0.017 (2) | 0.018 (2) | 0.000 | 0.0003 (19) | 0.000 |
| N127 | 0.026 (2) | 0.018 (2) | 0.021 (2) | 0.000 | 0.0008 (17) | 0.000 |
| C127 | 0.035 (3) | 0.025 (3) | 0.026 (3) | 0.000 | 0.002 (2) | 0.000 |
| Br122 | 0.0339 (2) | 0.01579 (18) | 0.0239 (2) | −0.00052 (15) | 0.00210 (15) | −0.00522 (14) |
| Br124 | 0.0290 (3) | 0.0231 (3) | 0.0155 (2) | 0.000 | −0.0005 (2) | 0.000 |
| C131 | 0.014 (2) | 0.019 (2) | 0.015 (2) | 0.000 | −0.0026 (17) | 0.000 |
| C132 | 0.0158 (16) | 0.0138 (16) | 0.0210 (17) | 0.0001 (13) | 0.0003 (13) | −0.0042 (13) |
| C133 | 0.0229 (18) | 0.0132 (17) | 0.0174 (17) | 0.0014 (14) | −0.0001 (13) | 0.0035 (13) |
| C134 | 0.018 (2) | 0.024 (3) | 0.015 (2) | 0.000 | −0.0016 (18) | 0.000 |
| N137 | 0.019 (2) | 0.017 (2) | 0.018 (2) | 0.000 | 0.0008 (16) | 0.000 |
| C137 | 0.024 (3) | 0.019 (3) | 0.030 (3) | 0.000 | −0.001 (2) | 0.000 |
| Br132 | 0.0360 (2) | 0.01500 (19) | 0.0234 (2) | −0.00111 (15) | −0.00260 (14) | −0.00427 (14) |
| Br134 | 0.0393 (3) | 0.0222 (3) | 0.0154 (3) | 0.000 | 0.0003 (2) | 0.000 |
(RNC-II) 1,3,5-Tribromo-2-isocyanobenzene - polytype II. Geometric parameters (Å, º)
| C121—N127 | 1.393 (6) | C131—N137 | 1.380 (6) |
| C121—C122i | 1.395 (4) | C131—C132ii | 1.392 (4) |
| C122—C123 | 1.382 (4) | C132—C133 | 1.380 (4) |
| C122—Br122 | 1.882 (3) | C132—Br132 | 1.883 (3) |
| C123—C124i | 1.381 (4) | C133—C134ii | 1.381 (4) |
| C123—H123 | 0.9500 | C133—H133 | 0.9500 |
| C124—Br124 | 1.897 (5) | C134—Br134 | 1.895 (4) |
| N127—C127 | 1.147 (6) | N137—C137 | 1.164 (6) |
| N127—C121—C122i | 120.4 (2) | N137—C131—C132ii | 120.3 (2) |
| C122—C121—C122i | 119.1 (4) | C132ii—C131—C132 | 119.5 (4) |
| C123—C122—C121 | 120.8 (3) | C133—C132—C131 | 120.5 (3) |
| C123—C122—Br122 | 119.6 (2) | C133—C132—Br132 | 119.9 (2) |
| C121—C122—Br122 | 119.6 (2) | C131—C132—Br132 | 119.5 (2) |
| C124—C123—C122 | 118.3 (3) | C132—C133—C134 | 118.7 (3) |
| C124—C123—H123 | 120.8 | C132—C133—H133 | 120.7 |
| C122—C123—H123 | 120.8 | C134—C133—H133 | 120.7 |
| C123—C124—C123i | 122.5 (4) | C133ii—C134—C133 | 122.1 (4) |
| C123i—C124—Br124 | 118.7 (2) | C133ii—C134—Br134 | 118.9 (2) |
| C127—N127—C121 | 178.5 (5) | C137—N137—C131 | 179.8 (4) |
| N127—C121—C122—C123 | 176.7 (3) | N137—C131—C132—C133 | −179.2 (3) |
| C122i—C121—C122—C123 | −1.0 (6) | C132ii—C131—C132—C133 | 1.6 (6) |
| N127—C121—C122—Br122 | −3.0 (5) | N137—C131—C132—Br132 | 0.6 (5) |
| C122i—C121—C122—Br122 | 179.30 (19) | C132ii—C131—C132—Br132 | −178.6 (2) |
| C121—C122—C123—C124 | −0.5 (5) | C131—C132—C133—C134 | −0.2 (5) |
| Br122—C122—C123—C124 | 179.2 (3) | Br132—C132—C133—C134 | −179.9 (3) |
| C122—C123—C124—C123i | 2.1 (7) | C132—C133—C134—C133ii | −1.3 (7) |
| C122—C123—C124—Br124 | −177.4 (2) | C132—C133—C134—Br134 | 179.3 (3) |
Symmetry codes: (i) x, −y+3/2, z; (ii) x, −y+1/2, z.
(RNC-II) 1,3,5-Tribromo-2-isocyanobenzene - polytype II. Hydrogen-bond geometry (Å, º)
| D—H···A | D—H | H···A | D···A | D—H···A |
| C123—H123···Br134iii | 0.95 | 3.08 | 3.976 (3) | 157 |
| C133—H133···Br124iv | 0.95 | 3.10 | 3.995 (3) | 157 |
Symmetry codes: (iii) x, y, z+1; (iv) x, y, z−1.
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Crystal structure: contains datablock(s) global, RCN-I, RCN-II, RCN-III, RNC-II. DOI: 10.1107/S2056989016000256/lh5796sup1.cif
Structure factors: contains datablock(s) RCN-I. DOI: 10.1107/S2056989016000256/lh5796RCN-Isup2.hkl
Supporting information file. DOI: 10.1107/S2056989016000256/lh5796RCN-Isup6.cml
Structure factors: contains datablock(s) RCN-II. DOI: 10.1107/S2056989016000256/lh5796RCN-IIsup3.hkl
Structure factors: contains datablock(s) RCN-III. DOI: 10.1107/S2056989016000256/lh5796RCN-IIIsup4.hkl
Structure factors: contains datablock(s) RNC-II. DOI: 10.1107/S2056989016000256/lh5796RNC-IIsup5.hkl
Additional supporting information: crystallographic information; 3D view; checkCIF report