organic compounds
2-Methyl-N-(pyrazin-2-yl)propanamide–1,2,4,5-tetrafluoro-3,6-diiodobenzene (2/1)
aFaculty of Chemistry, University of Opole, Oleska 48, 45-052 Opole, Poland, and bFaculty of Chemical Technology and Engineering, University of Technology and Life Sciences, Seminaryjna 3, 85-326 Bydgoszcz, Poland
*Correspondence e-mail: bdziuk@uni.opole.pl
In the title compound, C8H11N3O·0.5C6F4I2, molecules of iPr-substituted pyrazine are co-crystallized with 1,4-diiodo-2,3,5,6-tetrafluorobenzene. The complete molecule of 1,4-diiodo-2,3,5,6-tetrafluorobenzene is generated by an inversion centre at the middle of the aromatic ring. Both molecules have normal geometry and the iPr acylamine group is disordered over two sets of sites with an occupancy ratio of 0.51:0.49. In the crystal, the components are linked by I⋯N halogen bonds [2.830 (2) Å] and C—H⋯F interactions are observed.
Keywords: 2-aminopyrazine; halogen bonds; disorder; crystal structure.
CCDC reference: 1504625
Structure description
The aim of our study was obtain a series of crystals in which halogen bonding is one of the stabilizing forces. It is known that steric effects can be a factor that tunes the type of doubly hydrogen-bonded dimers both in solution and in the solid state. This has previously been shown for 2-acylaminopyridines (Ośmiałowski et al., 2010). Since steric effects may control the stability of the dimer our intention was to check if the dimer carrying a middle-size group (iPr) would be disturbed in the solid state. The same iPr group in 2-acylaminopyridine allowed efficient dimerization, while adamantyl did not either in 2-acylaminopyridine (Ośmiałowski et al., 2010) or in the analogous pyrazine (Dziuk et al., 2016). In the present work, the iPr substituted-pyrazine was co-crystallized with 1,4-diiodo-2,3,5,6-tetrafluorobenzene (Fig. 1).
The N-(pyrazin-2-yl)propanamide and a half-molecule of 1,2,4,5-tetrafluoro-3,6-diiodobenzene. The geometry of 2-methyl-N-(pyrazin-2-yl)propanamide is normal, and corresponds well with similar compounds (Ośmiałowski et al., 2010; Aakeröy et al., 2006; Dziuk et al.,2016). The iPr acylamine group is disordered. The atoms are split between two positions with occupancy factors of 0.49 and 0.51.
comprises partially disordered 2-methyl-In the crystal, I1⋯N2i [2.830 (2) Å; symmetry code: (i) −x + , y + , −z + ] halogen-bonding interactions connect the molecules into two C8H11N3O.C6F4I2 units arranged in a herringbone packing agreement (Fig. 2). The units are connected through C—H⋯F contacts (Table 1), forming infinite layers. The estimated distance between adjacent layers is 3.636 Å. The 2,2-dimethyl-N-(pyrazin-2-yl)acetamide molecules are connected by N—H⋯O hydrogen bonds (Table 1).
Synthesis and crystallization
The parent pyrazine was obtained using a reported procedure by reaction of 2-aminopyrazine with isobutyryl chloride (Dziuk et al., 2016) in the presence of triethylamine. The co-crystallization was performed by mixing a 1:1 molar ratio of the studied compounds in chloroform followed by slow evaporation of the solvent.
Refinement
Crystal data, data collection and structure . The isopropylacylamine group is disordered over two positions. of the site-occupation factors lead to a ratio of 0.509 (7)/0.491 (7). Since they correlate with the displacement parameters, they were fixed at 0.51 and 0.49. The displacement parameters of the disordered atoms were restrained to be equal to those of the atoms to which they are bonded and they were restrained to an isotropic behaviour.
details are summarized in Table 2Structural data
CCDC reference: 1504625
10.1107/S2414314616014668/bt4027sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: 10.1107/S2414314616014668/bt4027Isup2.hkl
Data collection: CrysAlis CCD (Oxford Diffraction, 2008); cell
CrysAlis CCD (Oxford Diffraction, 2008); data reduction: CrysAlis CCD (Oxford Diffraction, 2008); program(s) used to solve structure: SHELXS2013 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2015); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL2013 (Sheldrick, 2015).C8H11N3O·0.5C6F4I2 | F(000) = 708 |
Mr = 366.13 | Dx = 1.938 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
a = 10.6503 (2) Å | Cell parameters from 7645 reflections |
b = 10.6112 (2) Å | θ = 3.1–25.0° |
c = 11.2086 (2) Å | µ = 2.57 mm−1 |
β = 97.857 (2)° | T = 100 K |
V = 1254.82 (4) Å3 | Plate, colourless |
Z = 4 | 0.03 × 0.02 × 0.01 mm |
Oxford Diffraction Xcalibur diffractometer | 2209 independent reflections |
Radiation source: fine-focus sealed tube | 2073 reflections with I > 2σ(I) |
Detector resolution: 1024 x 1024 with blocks 2 x 2 pixels mm-1 | Rint = 0.011 |
ω scans | θmax = 25.0°, θmin = 3.1° |
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2008) | h = −12→9 |
Tmin = 0.912, Tmax = 1.000 | k = −12→12 |
7645 measured reflections | l = −13→13 |
Refinement on F2 | 256 restraints |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.015 | H-atom parameters constrained |
wR(F2) = 0.036 | w = 1/[σ2(Fo2) + (0.0188P)2 + 1.2735P] where P = (Fo2 + 2Fc2)/3 |
S = 1.02 | (Δ/σ)max = 0.002 |
2209 reflections | Δρmax = 0.63 e Å−3 |
217 parameters | Δρmin = −0.34 e Å−3 |
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. |
x | y | z | Uiso*/Ueq | Occ. (<1) | |
I1 | 0.94381 (2) | 0.23915 (2) | 0.78247 (2) | 0.01620 (6) | |
F1 | 1.07201 (16) | 0.23859 (11) | 1.06151 (12) | 0.0363 (4) | |
F2 | 0.89029 (14) | −0.05718 (12) | 0.77398 (11) | 0.0293 (3) | |
N1 | 0.66750 (18) | 0.17037 (18) | −0.00151 (18) | 0.0265 (4) | |
N2 | 0.61307 (16) | −0.05394 (16) | −0.12506 (15) | 0.0179 (4) | |
C1 | 0.6789 (2) | 0.0598 (2) | 0.05489 (19) | 0.0227 (5) | |
C2 | 0.6296 (2) | 0.1675 (2) | −0.1196 (2) | 0.0240 (5) | |
H2A | 0.6214 | 0.2432 | −0.1618 | 0.029* | |
C3 | 0.60207 (19) | 0.05664 (19) | −0.18178 (19) | 0.0190 (4) | |
H3A | 0.5755 | 0.0591 | −0.2643 | 0.023* | |
C4 | 0.6516 (2) | −0.0536 (2) | −0.00667 (18) | 0.0204 (4) | |
H4A | 0.6604 | −0.1294 | 0.0352 | 0.024* | |
N3A | 0.7268 (4) | 0.0522 (4) | 0.1841 (4) | 0.0145 (10) | 0.51 |
H3AA | 0.7500 | 0.1233 | 0.2169 | 0.017* | 0.51 |
O1A | 0.7017 (4) | −0.1154 (5) | 0.2410 (4) | 0.0215 (10) | 0.51 |
C5A | 0.7410 (5) | −0.0491 (6) | 0.2620 (4) | 0.0156 (10) | 0.51 |
C6A | 0.7550 (4) | 0.0511 (4) | 0.3894 (4) | 0.0182 (8) | 0.51 |
H6AA | 0.7166 | 0.1344 | 0.3734 | 0.022* | 0.51 |
C7A | 0.6945 (8) | −0.0258 (8) | 0.4767 (9) | 0.028 (2) | 0.51 |
H7AA | 0.6988 | 0.0188 | 0.5517 | 0.042* | 0.51 |
H7AB | 0.7383 | −0.1047 | 0.4897 | 0.042* | 0.51 |
H7AC | 0.6074 | −0.0410 | 0.4452 | 0.042* | 0.51 |
C8A | 0.8965 (5) | 0.0535 (6) | 0.4199 (5) | 0.0451 (13) | 0.51 |
H8AA | 0.9196 | 0.1040 | 0.4905 | 0.068* | 0.51 |
H8AB | 0.9332 | 0.0888 | 0.3538 | 0.068* | 0.51 |
H8AC | 0.9274 | −0.0308 | 0.4349 | 0.068* | 0.51 |
N3B | 0.7097 (4) | 0.0885 (4) | 0.1731 (4) | 0.0140 (11) | 0.49 |
H3BA | 0.7229 | 0.1661 | 0.1934 | 0.017* | 0.49 |
O1B | 0.7231 (4) | −0.1556 (4) | 0.2297 (4) | 0.0187 (10) | 0.49 |
C5B | 0.7207 (4) | −0.0021 (5) | 0.2620 (4) | 0.0121 (10) | 0.49 |
C6B | 0.7841 (4) | −0.0153 (4) | 0.3948 (4) | 0.0140 (8) | 0.49 |
H6BA | 0.8511 | −0.0793 | 0.4058 | 0.017* | 0.49 |
C7B | 0.6716 (7) | −0.0435 (8) | 0.4675 (8) | 0.0176 (16) | 0.49 |
H7BA | 0.7041 | −0.0554 | 0.5510 | 0.026* | 0.49 |
H7BB | 0.6284 | −0.1184 | 0.4366 | 0.026* | 0.49 |
H7BC | 0.6136 | 0.0262 | 0.4596 | 0.026* | 0.49 |
C8B | 0.8330 (4) | 0.1179 (4) | 0.4183 (4) | 0.0203 (9) | 0.49 |
H8BA | 0.8771 | 0.1234 | 0.4988 | 0.030* | 0.49 |
H8BB | 0.7629 | 0.1756 | 0.4094 | 0.030* | 0.49 |
H8BC | 0.8898 | 0.1389 | 0.3618 | 0.030* | 0.49 |
C9 | 0.97972 (18) | 0.09653 (18) | 0.91234 (17) | 0.0146 (4) | |
C10 | 1.0348 (2) | 0.12112 (18) | 1.02892 (18) | 0.0188 (4) | |
C11 | 0.94546 (19) | −0.02697 (19) | 0.88570 (18) | 0.0168 (4) |
U11 | U22 | U33 | U12 | U13 | U23 | |
I1 | 0.02291 (8) | 0.01364 (8) | 0.01189 (8) | 0.00054 (5) | 0.00183 (5) | 0.00207 (5) |
F1 | 0.0709 (11) | 0.0135 (6) | 0.0202 (7) | −0.0117 (6) | −0.0093 (7) | 0.0003 (5) |
F2 | 0.0500 (8) | 0.0209 (6) | 0.0134 (6) | −0.0078 (6) | −0.0085 (6) | −0.0003 (5) |
N1 | 0.0237 (10) | 0.0266 (10) | 0.0299 (11) | −0.0054 (8) | 0.0066 (8) | −0.0123 (8) |
N2 | 0.0209 (9) | 0.0187 (9) | 0.0141 (9) | −0.0022 (7) | 0.0026 (7) | −0.0027 (7) |
C1 | 0.0160 (10) | 0.0363 (13) | 0.0169 (11) | −0.0085 (9) | 0.0063 (9) | −0.0085 (9) |
C2 | 0.0229 (11) | 0.0191 (11) | 0.0303 (13) | −0.0013 (9) | 0.0053 (9) | 0.0004 (9) |
C3 | 0.0201 (11) | 0.0228 (11) | 0.0145 (10) | 0.0002 (8) | 0.0044 (8) | 0.0000 (8) |
C4 | 0.0215 (11) | 0.0249 (11) | 0.0148 (11) | −0.0055 (9) | 0.0028 (9) | 0.0010 (8) |
N3A | 0.0159 (13) | 0.0136 (13) | 0.0136 (13) | 0.0007 (9) | 0.0003 (9) | −0.0022 (9) |
O1A | 0.0263 (17) | 0.0198 (17) | 0.0177 (15) | 0.0012 (15) | 0.0009 (13) | 0.0009 (14) |
C5A | 0.0153 (13) | 0.0164 (13) | 0.0154 (13) | 0.0006 (10) | 0.0026 (9) | 0.0017 (9) |
C6A | 0.0192 (12) | 0.0183 (12) | 0.0171 (11) | 0.0010 (9) | 0.0021 (9) | −0.0007 (9) |
C7A | 0.032 (3) | 0.027 (3) | 0.026 (3) | −0.0028 (18) | 0.0053 (18) | 0.0005 (16) |
C8A | 0.0382 (19) | 0.057 (2) | 0.039 (2) | −0.0001 (17) | 0.0031 (16) | −0.0132 (16) |
N3B | 0.0150 (13) | 0.0136 (13) | 0.0131 (13) | 0.0009 (9) | 0.0005 (9) | −0.0006 (9) |
O1B | 0.0217 (16) | 0.0184 (17) | 0.0157 (15) | 0.0061 (14) | 0.0018 (12) | −0.0010 (13) |
C5B | 0.0118 (13) | 0.0119 (13) | 0.0127 (13) | −0.0011 (9) | 0.0023 (9) | −0.0007 (9) |
C6B | 0.0146 (11) | 0.0141 (11) | 0.0129 (11) | −0.0001 (9) | 0.0008 (9) | 0.0002 (9) |
C7B | 0.018 (2) | 0.023 (2) | 0.013 (2) | −0.0051 (16) | 0.0037 (16) | 0.0014 (15) |
C8B | 0.0250 (16) | 0.0171 (15) | 0.0173 (16) | −0.0028 (14) | −0.0019 (14) | 0.0003 (13) |
C9 | 0.0166 (10) | 0.0144 (10) | 0.0131 (10) | 0.0022 (8) | 0.0034 (8) | 0.0028 (7) |
C10 | 0.0263 (11) | 0.0118 (9) | 0.0180 (11) | −0.0025 (8) | 0.0014 (9) | −0.0015 (8) |
C11 | 0.0204 (11) | 0.0187 (10) | 0.0106 (10) | −0.0004 (8) | −0.0006 (8) | −0.0013 (8) |
I1—C9 | 2.0983 (19) | C7A—H7AB | 0.9600 |
F1—C10 | 1.343 (2) | C7A—H7AC | 0.9600 |
F2—C11 | 1.347 (2) | C8A—H8AA | 0.9600 |
N1—C2 | 1.330 (3) | C8A—H8AB | 0.9600 |
N1—C1 | 1.330 (3) | C8A—H8AC | 0.9600 |
N2—C3 | 1.332 (3) | N3B—C5B | 1.378 (7) |
N2—C4 | 1.334 (3) | N3B—H3BA | 0.8600 |
C1—N3B | 1.356 (5) | O1B—C5B | 1.670 (6) |
C1—C4 | 1.398 (3) | C5B—C6B | 1.554 (6) |
C1—N3A | 1.471 (5) | C6B—C8B | 1.517 (6) |
C2—C3 | 1.379 (3) | C6B—C7B | 1.567 (9) |
C2—H2A | 0.9300 | C6B—H6BA | 0.9800 |
C3—H3A | 0.9300 | C7B—H7BA | 0.9600 |
C4—H4A | 0.9300 | C7B—H7BB | 0.9600 |
N3A—C5A | 1.380 (7) | C7B—H7BC | 0.9600 |
N3A—H3AA | 0.8600 | C8B—H8BA | 0.9600 |
O1A—C5A | 0.836 (6) | C8B—H8BB | 0.9600 |
C5A—C6A | 1.770 (7) | C8B—H8BC | 0.9600 |
C6A—C7A | 1.487 (10) | C9—C11 | 1.382 (3) |
C6A—C8A | 1.500 (7) | C9—C10 | 1.382 (3) |
C6A—H6AA | 0.9800 | C10—C11i | 1.379 (3) |
C7A—H7AA | 0.9600 | C11—C10i | 1.379 (3) |
C2—N1—C1 | 116.62 (19) | C6A—C8A—H8AC | 109.5 |
C3—N2—C4 | 117.87 (18) | H8AA—C8A—H8AC | 109.5 |
N1—C1—N3B | 105.1 (3) | H8AB—C8A—H8AC | 109.5 |
N1—C1—C4 | 121.70 (19) | C1—N3B—C5B | 122.3 (4) |
N3B—C1—C4 | 133.0 (3) | C1—N3B—H3BA | 118.8 |
N1—C1—N3A | 120.9 (2) | C5B—N3B—H3BA | 118.8 |
C4—C1—N3A | 117.4 (3) | N3B—C5B—C6B | 137.6 (4) |
N1—C2—C3 | 122.5 (2) | N3B—C5B—O1B | 121.8 (4) |
N1—C2—H2A | 118.7 | C6B—C5B—O1B | 95.8 (4) |
C3—C2—H2A | 118.7 | C8B—C6B—C5B | 100.2 (3) |
N2—C3—C2 | 120.77 (19) | C8B—C6B—C7B | 110.8 (5) |
N2—C3—H3A | 119.6 | C5B—C6B—C7B | 104.6 (4) |
C2—C3—H3A | 119.6 | C8B—C6B—H6BA | 113.4 |
N2—C4—C1 | 120.5 (2) | C5B—C6B—H6BA | 113.4 |
N2—C4—H4A | 119.7 | C7B—C6B—H6BA | 113.4 |
C1—C4—H4A | 119.7 | C6B—C7B—H7BA | 109.5 |
C5A—N3A—C1 | 131.2 (4) | C6B—C7B—H7BB | 109.5 |
C5A—N3A—H3AA | 114.4 | H7BA—C7B—H7BB | 109.5 |
C1—N3A—H3AA | 114.4 | C6B—C7B—H7BC | 109.5 |
O1A—C5A—N3A | 118.0 (6) | H7BA—C7B—H7BC | 109.5 |
O1A—C5A—C6A | 135.7 (6) | H7BB—C7B—H7BC | 109.5 |
N3A—C5A—C6A | 91.8 (4) | C6B—C8B—H8BA | 109.5 |
C7A—C6A—C8A | 111.8 (5) | C6B—C8B—H8BB | 109.5 |
C7A—C6A—C5A | 101.9 (5) | H8BA—C8B—H8BB | 109.5 |
C8A—C6A—C5A | 99.5 (4) | C6B—C8B—H8BC | 109.5 |
C7A—C6A—H6AA | 114.1 | H8BA—C8B—H8BC | 109.5 |
C8A—C6A—H6AA | 114.1 | H8BB—C8B—H8BC | 109.5 |
C5A—C6A—H6AA | 114.1 | C11—C9—C10 | 116.65 (18) |
C6A—C7A—H7AA | 109.5 | C11—C9—I1 | 121.09 (14) |
C6A—C7A—H7AB | 109.5 | C10—C9—I1 | 122.23 (15) |
H7AA—C7A—H7AB | 109.5 | F1—C10—C11i | 118.16 (18) |
C6A—C7A—H7AC | 109.5 | F1—C10—C9 | 120.23 (18) |
H7AA—C7A—H7AC | 109.5 | C11i—C10—C9 | 121.60 (19) |
H7AB—C7A—H7AC | 109.5 | F2—C11—C10i | 118.57 (18) |
C6A—C8A—H8AA | 109.5 | F2—C11—C9 | 119.68 (17) |
C6A—C8A—H8AB | 109.5 | C10i—C11—C9 | 121.75 (18) |
H8AA—C8A—H8AB | 109.5 |
Symmetry code: (i) −x+2, −y, −z+2. |
D—H···A | D—H | H···A | D···A | D—H···A |
C2—H2A···F2ii | 0.93 | 2.46 | 3.388 (3) | 178 |
C4—H4A···O1A | 0.93 | 2.29 | 2.831 (5) | 116 |
C4—H4A···O1B | 0.93 | 2.21 | 2.867 (5) | 127 |
C6A—H6AA···I1iii | 0.98 | 3.24 | 4.035 (5) | 140 |
N3A—H3AA···O1Aii | 0.86 | 2.85 | 3.681 (6) | 164 |
N3B—H3BA···O1Bii | 0.86 | 2.13 | 2.976 (6) | 170 |
Symmetry codes: (ii) −x+3/2, y+1/2, −z+1/2; (iii) x−1/2, −y+1/2, z−1/2. |
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