



Supporting information
![]() | Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536810042376/jh2218sup1.cif |
![]() | Structure factor file (CIF format) https://doi.org/10.1107/S1600536810042376/jh2218Isup2.hkl |
CCDC reference: 799705
Key indicators
- Single-crystal X-ray study
- T = 173 K
- Mean
(C-C) = 0.002 Å
- R factor = 0.037
- wR factor = 0.096
- Data-to-parameter ratio = 19.3
checkCIF/PLATON results
No syntax errors found
Alert level C PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L= 0.600 3 PLAT480_ALERT_4_C Long H...A H-Bond Reported H5 .. N3 .. 2.72 Ang. PLAT480_ALERT_4_C Long H...A H-Bond Reported H11 .. F2 .. 2.66 Ang. PLAT912_ALERT_4_C Missing # of FCF Reflections Above STh/L= 0.600 5
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 4 ALERT level C = Check and explain 0 ALERT level G = General alerts; check 0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 0 ALERT type 2 Indicator that the structure model may be wrong or deficient 1 ALERT type 3 Indicator that the structure quality may be low 3 ALERT type 4 Improvement, methodology, query or suggestion 0 ALERT type 5 Informative message, check
The title compound was purchased from the Dr. Ehrenstorfer GmbH Company. Slow evaporation of a CH2Cl2 solution gave single crystals suitable for X-ray analysis.
All H-atoms were positioned geometrically and refined using a riding model with d(C—H) = 0.95 Å, Uiso = 1.2Ueq(C) for aromatic, d(C—H) = 0.99 Å, Uiso = 1.2Ueq(C) for CH2 and d(C—H) = 0.98 Å, Uiso = 1.5Ueq(C) for CH3 groups.
Triflumizole (systematic name: [(E)-4-chloro-α,α,α-trifluoro- N-(1-imidazol-1-yl-2-propoxyethylidene)-o-toluidine]), is a well known fungicide discoverd by Nippon Soda Co. Ltd., Japan (İnam et al., 2006; Nakata et al., 1991). However it's crystal structure has not been reported yet.
In the title compound (Scheme 1, Fig.1), the dihedral angle between the paniline and imidazole ring planes is 81.80 (4)°. All bond lengths and bond angles of core part consisting of aniline and methylimidazole groups are are comparable to those observed in similar structures (Long et al., 2008).
In the crystal structure, as shown in Fig. 2, weak C—H···X (X = N, O or F) hydrogen bonds are observed (Table 1). Weak intermolecular C—H···π interactions with 3.64 Å also exist. These intermolecular interactions may be contribute to the stabilization of the packing.
For the toxicity and insecticidal properties of the title compound, see: İnam et al. (2006); Nakata et al. (1991). For related structures, see: Long et al. (2008).
Data collection: APEX2 (Bruker, 2006); cell refinement: SAINT (Bruker, 2006); data reduction: SAINT (Bruker, 2006); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008) and DIAMOND (Brandenburg, 1998); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).
C15H15ClF3N3O | F(000) = 712 |
Mr = 345.75 | Dx = 1.423 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 5704 reflections |
a = 9.2815 (6) Å | θ = 2.2–28.2° |
b = 20.5078 (14) Å | µ = 0.27 mm−1 |
c = 8.6339 (6) Å | T = 173 K |
β = 100.835 (1)° | Block, colourless |
V = 1614.11 (19) Å3 | 0.15 × 0.13 × 0.11 mm |
Z = 4 |
Bruker APEXII CCD diffractometer | 4028 independent reflections |
Radiation source: fine-focus sealed tube | 3317 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.029 |
φ and ω scans | θmax = 28.4°, θmin = 2.0° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −12→12 |
Tmin = 0.960, Tmax = 0.971 | k = −27→26 |
16571 measured reflections | l = −11→11 |
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)] = 0.037 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.096 | H-atom parameters constrained |
S = 1.03 | w = 1/[σ2(Fo2) + (0.0411P)2 + 0.5111P] where P = (Fo2 + 2Fc2)/3 |
4028 reflections | (Δ/σ)max = 0.001 |
209 parameters | Δρmax = 0.30 e Å−3 |
0 restraints | Δρmin = −0.28 e Å−3 |
C15H15ClF3N3O | V = 1614.11 (19) Å3 |
Mr = 345.75 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 9.2815 (6) Å | µ = 0.27 mm−1 |
b = 20.5078 (14) Å | T = 173 K |
c = 8.6339 (6) Å | 0.15 × 0.13 × 0.11 mm |
β = 100.835 (1)° |
Bruker APEXII CCD diffractometer | 4028 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 3317 reflections with I > 2σ(I) |
Tmin = 0.960, Tmax = 0.971 | Rint = 0.029 |
16571 measured reflections |
R[F2 > 2σ(F2)] = 0.037 | 0 restraints |
wR(F2) = 0.096 | H-atom parameters constrained |
S = 1.03 | Δρmax = 0.30 e Å−3 |
4028 reflections | Δρmin = −0.28 e Å−3 |
209 parameters |
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. |
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
x | y | z | Uiso*/Ueq | ||
Cl1 | 1.49537 (5) | 0.75199 (2) | 0.20992 (6) | 0.05563 (14) | |
F1 | 0.88158 (9) | 0.70250 (5) | 0.32069 (12) | 0.0519 (3) | |
F2 | 1.00525 (12) | 0.66642 (5) | 0.53792 (12) | 0.0601 (3) | |
F3 | 1.03828 (12) | 0.76378 (5) | 0.46407 (13) | 0.0573 (3) | |
N1 | 1.01160 (11) | 0.57214 (5) | 0.27790 (12) | 0.0262 (2) | |
N2 | 0.80266 (11) | 0.51277 (5) | 0.19825 (12) | 0.0253 (2) | |
N3 | 0.60502 (12) | 0.44946 (6) | 0.16697 (13) | 0.0331 (3) | |
O1 | 0.81606 (10) | 0.56645 (4) | −0.10396 (10) | 0.0282 (2) | |
C1 | 1.01505 (16) | 0.70258 (7) | 0.41218 (17) | 0.0362 (3) | |
C2 | 1.13094 (14) | 0.67960 (6) | 0.32611 (15) | 0.0277 (3) | |
C3 | 1.24709 (15) | 0.72066 (6) | 0.31239 (16) | 0.0331 (3) | |
H3 | 1.2553 | 0.7622 | 0.3617 | 0.040* | |
C4 | 1.34990 (15) | 0.70066 (7) | 0.22698 (17) | 0.0340 (3) | |
C5 | 1.33924 (15) | 0.64078 (7) | 0.15219 (17) | 0.0337 (3) | |
H5 | 1.4096 | 0.6280 | 0.0911 | 0.040* | |
C6 | 1.22451 (14) | 0.59969 (6) | 0.16759 (15) | 0.0298 (3) | |
H6 | 1.2175 | 0.5582 | 0.1179 | 0.036* | |
C7 | 1.11926 (13) | 0.61799 (6) | 0.25445 (14) | 0.0250 (2) | |
C8 | 0.89657 (13) | 0.56432 (6) | 0.17534 (14) | 0.0244 (2) | |
C9 | 0.66245 (13) | 0.50171 (6) | 0.11769 (15) | 0.0276 (3) | |
H9 | 0.6131 | 0.5290 | 0.0356 | 0.033* | |
C10 | 0.71276 (16) | 0.42502 (7) | 0.28583 (17) | 0.0365 (3) | |
H10 | 0.7026 | 0.3867 | 0.3446 | 0.044* | |
C11 | 0.83378 (15) | 0.46272 (7) | 0.30736 (16) | 0.0328 (3) | |
H11 | 0.9220 | 0.4563 | 0.3818 | 0.039* | |
C12 | 0.84433 (15) | 0.60608 (6) | 0.03188 (15) | 0.0305 (3) | |
H12A | 0.7538 | 0.6295 | 0.0439 | 0.037* | |
H12B | 0.9202 | 0.6389 | 0.0211 | 0.037* | |
C13 | 0.74287 (15) | 0.60238 (7) | −0.23828 (15) | 0.0316 (3) | |
H13A | 0.8080 | 0.6373 | −0.2643 | 0.038* | |
H13B | 0.6532 | 0.6230 | −0.2142 | 0.038* | |
C14 | 0.70299 (16) | 0.55717 (7) | −0.37587 (16) | 0.0364 (3) | |
H14A | 0.6424 | 0.5211 | −0.3469 | 0.044* | |
H14B | 0.7936 | 0.5381 | −0.4018 | 0.044* | |
C15 | 0.61863 (18) | 0.59207 (9) | −0.51998 (17) | 0.0450 (4) | |
H15A | 0.5288 | 0.6109 | −0.4948 | 0.067* | |
H15B | 0.5931 | 0.5609 | −0.6069 | 0.067* | |
H15C | 0.6796 | 0.6269 | −0.5512 | 0.067* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cl1 | 0.0433 (2) | 0.0460 (2) | 0.0761 (3) | −0.02137 (18) | 0.0072 (2) | 0.0045 (2) |
F1 | 0.0325 (5) | 0.0604 (6) | 0.0595 (6) | 0.0106 (4) | 0.0002 (4) | −0.0165 (5) |
F2 | 0.0738 (7) | 0.0644 (7) | 0.0487 (6) | 0.0213 (5) | 0.0286 (5) | 0.0098 (5) |
F3 | 0.0570 (6) | 0.0406 (5) | 0.0737 (7) | 0.0044 (4) | 0.0108 (5) | −0.0297 (5) |
N1 | 0.0267 (5) | 0.0227 (5) | 0.0269 (5) | −0.0006 (4) | −0.0003 (4) | −0.0005 (4) |
N2 | 0.0244 (5) | 0.0243 (5) | 0.0253 (5) | −0.0015 (4) | −0.0002 (4) | 0.0002 (4) |
N3 | 0.0271 (5) | 0.0376 (6) | 0.0344 (6) | −0.0056 (5) | 0.0048 (5) | −0.0006 (5) |
O1 | 0.0319 (5) | 0.0266 (4) | 0.0238 (4) | 0.0014 (4) | −0.0008 (3) | 0.0011 (3) |
C1 | 0.0377 (7) | 0.0304 (7) | 0.0379 (7) | 0.0050 (6) | 0.0007 (6) | −0.0067 (6) |
C2 | 0.0290 (6) | 0.0236 (6) | 0.0273 (6) | 0.0025 (5) | −0.0032 (5) | −0.0023 (5) |
C3 | 0.0363 (7) | 0.0219 (6) | 0.0363 (7) | −0.0030 (5) | −0.0057 (6) | −0.0032 (5) |
C4 | 0.0291 (6) | 0.0288 (7) | 0.0405 (7) | −0.0075 (5) | −0.0025 (5) | 0.0042 (5) |
C5 | 0.0297 (7) | 0.0331 (7) | 0.0376 (7) | 0.0004 (5) | 0.0046 (5) | 0.0011 (5) |
C6 | 0.0314 (6) | 0.0233 (6) | 0.0331 (6) | 0.0000 (5) | 0.0020 (5) | −0.0043 (5) |
C7 | 0.0251 (6) | 0.0210 (6) | 0.0255 (6) | −0.0004 (4) | −0.0036 (4) | 0.0001 (4) |
C8 | 0.0269 (6) | 0.0199 (5) | 0.0251 (5) | 0.0006 (4) | 0.0015 (5) | −0.0016 (4) |
C9 | 0.0218 (6) | 0.0324 (6) | 0.0274 (6) | −0.0008 (5) | 0.0017 (5) | −0.0021 (5) |
C10 | 0.0362 (7) | 0.0334 (7) | 0.0390 (7) | −0.0065 (6) | 0.0047 (6) | 0.0067 (6) |
C11 | 0.0318 (7) | 0.0303 (7) | 0.0330 (7) | −0.0016 (5) | −0.0023 (5) | 0.0068 (5) |
C12 | 0.0368 (7) | 0.0221 (6) | 0.0282 (6) | −0.0036 (5) | −0.0049 (5) | 0.0016 (5) |
C13 | 0.0366 (7) | 0.0303 (7) | 0.0255 (6) | −0.0019 (5) | 0.0000 (5) | 0.0058 (5) |
C14 | 0.0363 (7) | 0.0427 (8) | 0.0281 (6) | 0.0066 (6) | 0.0006 (5) | −0.0022 (6) |
C15 | 0.0466 (9) | 0.0602 (10) | 0.0257 (7) | 0.0056 (7) | 0.0005 (6) | 0.0017 (6) |
Cl1—C4 | 1.7399 (14) | C5—H5 | 0.9500 |
F1—C1 | 1.3382 (17) | C6—C7 | 1.3903 (18) |
F2—C1 | 1.3318 (18) | C6—H6 | 0.9500 |
F3—C1 | 1.3364 (16) | C8—C12 | 1.5089 (16) |
N1—C8 | 1.2626 (15) | C9—H9 | 0.9500 |
N1—C7 | 1.4141 (16) | C10—C11 | 1.3473 (19) |
N2—C9 | 1.3743 (16) | C10—H10 | 0.9500 |
N2—C11 | 1.3865 (16) | C11—H11 | 0.9500 |
N2—C8 | 1.4076 (16) | C12—H12A | 0.9900 |
N3—C9 | 1.3033 (17) | C12—H12B | 0.9900 |
N3—C10 | 1.3851 (18) | C13—C14 | 1.4976 (19) |
O1—C12 | 1.4104 (15) | C13—H13A | 0.9900 |
O1—C13 | 1.4328 (15) | C13—H13B | 0.9900 |
C1—C2 | 1.4940 (19) | C14—C15 | 1.5189 (19) |
C2—C3 | 1.3904 (19) | C14—H14A | 0.9900 |
C2—C7 | 1.4022 (16) | C14—H14B | 0.9900 |
C3—C4 | 1.374 (2) | C15—H15A | 0.9800 |
C3—H3 | 0.9500 | C15—H15B | 0.9800 |
C4—C5 | 1.382 (2) | C15—H15C | 0.9800 |
C5—C6 | 1.3839 (18) | ||
C8—N1—C7 | 120.74 (10) | N3—C9—N2 | 112.15 (11) |
C9—N2—C11 | 106.15 (10) | N3—C9—H9 | 123.9 |
C9—N2—C8 | 127.26 (10) | N2—C9—H9 | 123.9 |
C11—N2—C8 | 126.59 (10) | C11—C10—N3 | 111.21 (12) |
C9—N3—C10 | 104.87 (11) | C11—C10—H10 | 124.4 |
C12—O1—C13 | 111.25 (9) | N3—C10—H10 | 124.4 |
F2—C1—F3 | 106.33 (12) | C10—C11—N2 | 105.62 (12) |
F2—C1—F1 | 106.44 (13) | C10—C11—H11 | 127.2 |
F3—C1—F1 | 105.80 (11) | N2—C11—H11 | 127.2 |
F2—C1—C2 | 113.31 (11) | O1—C12—C8 | 109.66 (10) |
F3—C1—C2 | 112.15 (12) | O1—C12—H12A | 109.7 |
F1—C1—C2 | 112.28 (11) | C8—C12—H12A | 109.7 |
C3—C2—C7 | 120.33 (12) | O1—C12—H12B | 109.7 |
C3—C2—C1 | 119.58 (11) | C8—C12—H12B | 109.7 |
C7—C2—C1 | 120.04 (12) | H12A—C12—H12B | 108.2 |
C4—C3—C2 | 119.53 (12) | O1—C13—C14 | 109.42 (11) |
C4—C3—H3 | 120.2 | O1—C13—H13A | 109.8 |
C2—C3—H3 | 120.2 | C14—C13—H13A | 109.8 |
C3—C4—C5 | 121.34 (12) | O1—C13—H13B | 109.8 |
C3—C4—Cl1 | 119.55 (11) | C14—C13—H13B | 109.8 |
C5—C4—Cl1 | 119.10 (11) | H13A—C13—H13B | 108.2 |
C4—C5—C6 | 119.00 (13) | C13—C14—C15 | 111.75 (12) |
C4—C5—H5 | 120.5 | C13—C14—H14A | 109.3 |
C6—C5—H5 | 120.5 | C15—C14—H14A | 109.3 |
C5—C6—C7 | 121.26 (12) | C13—C14—H14B | 109.3 |
C5—C6—H6 | 119.4 | C15—C14—H14B | 109.3 |
C7—C6—H6 | 119.4 | H14A—C14—H14B | 107.9 |
C6—C7—C2 | 118.52 (11) | C14—C15—H15A | 109.5 |
C6—C7—N1 | 119.00 (11) | C14—C15—H15B | 109.5 |
C2—C7—N1 | 122.29 (11) | H15A—C15—H15B | 109.5 |
N1—C8—N2 | 117.46 (11) | C14—C15—H15C | 109.5 |
N1—C8—C12 | 127.05 (11) | H15A—C15—H15C | 109.5 |
N2—C8—C12 | 115.44 (10) | H15B—C15—H15C | 109.5 |
F2—C1—C2—C3 | −118.75 (14) | C8—N1—C7—C2 | 100.78 (14) |
F3—C1—C2—C3 | 1.64 (18) | C7—N1—C8—N2 | 172.85 (11) |
F1—C1—C2—C3 | 120.62 (14) | C7—N1—C8—C12 | −9.71 (19) |
F2—C1—C2—C7 | 63.75 (16) | C9—N2—C8—N1 | 168.55 (12) |
F3—C1—C2—C7 | −175.86 (11) | C11—N2—C8—N1 | −11.52 (18) |
F1—C1—C2—C7 | −56.88 (17) | C9—N2—C8—C12 | −9.19 (18) |
C7—C2—C3—C4 | 0.52 (19) | C11—N2—C8—C12 | 170.74 (12) |
C1—C2—C3—C4 | −176.98 (13) | C10—N3—C9—N2 | 0.04 (15) |
C2—C3—C4—C5 | 0.9 (2) | C11—N2—C9—N3 | −0.19 (15) |
C2—C3—C4—Cl1 | −179.94 (10) | C8—N2—C9—N3 | 179.75 (11) |
C3—C4—C5—C6 | −1.7 (2) | C9—N3—C10—C11 | 0.13 (16) |
Cl1—C4—C5—C6 | 179.17 (10) | N3—C10—C11—N2 | −0.24 (16) |
C4—C5—C6—C7 | 1.0 (2) | C9—N2—C11—C10 | 0.25 (15) |
C5—C6—C7—C2 | 0.40 (19) | C8—N2—C11—C10 | −179.68 (12) |
C5—C6—C7—N1 | −174.60 (11) | C13—O1—C12—C8 | 170.09 (10) |
C3—C2—C7—C6 | −1.17 (18) | N1—C8—C12—O1 | 127.19 (13) |
C1—C2—C7—C6 | 176.31 (12) | N2—C8—C12—O1 | −55.33 (14) |
C3—C2—C7—N1 | 173.65 (11) | C12—O1—C13—C14 | −174.92 (11) |
C1—C2—C7—N1 | −8.86 (18) | O1—C13—C14—C15 | 177.36 (12) |
C8—N1—C7—C6 | −84.42 (15) |
Cg is the centroid of the N2,C9,N3,C10,C11 ring. |
D—H···A | D—H | H···A | D···A | D—H···A |
C5—H5···N3i | 0.95 | 2.72 | 3.4383 (18) | 133 |
C6—H6···O1i | 0.95 | 2.58 | 3.4604 (16) | 155 |
C11—H11···F2ii | 0.95 | 2.66 | 3.2063 (17) | 117 |
C12—H12B···F3iii | 0.99 | 2.37 | 3.3320 (16) | 163 |
C15—H15B···Cgiv | 0.98 | 2.82 | 3.6385 (18) | 141 |
Symmetry codes: (i) −x+2, −y+1, −z; (ii) −x+2, −y+1, −z+1; (iii) x, −y+3/2, z−1/2; (iv) x, y, z−1. |
Experimental details
Crystal data | |
Chemical formula | C15H15ClF3N3O |
Mr | 345.75 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 173 |
a, b, c (Å) | 9.2815 (6), 20.5078 (14), 8.6339 (6) |
β (°) | 100.835 (1) |
V (Å3) | 1614.11 (19) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.27 |
Crystal size (mm) | 0.15 × 0.13 × 0.11 |
Data collection | |
Diffractometer | Bruker APEXII CCD |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.960, 0.971 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 16571, 4028, 3317 |
Rint | 0.029 |
(sin θ/λ)max (Å−1) | 0.668 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.037, 0.096, 1.03 |
No. of reflections | 4028 |
No. of parameters | 209 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.30, −0.28 |
Computer programs: APEX2 (Bruker, 2006), SAINT (Bruker, 2006), SHELXTL (Sheldrick, 2008) and DIAMOND (Brandenburg, 1998).
Cg is the centroid of the N2,C9,N3,C10,C11 ring. |
D—H···A | D—H | H···A | D···A | D—H···A |
C5—H5···N3i | 0.95 | 2.72 | 3.4383 (18) | 133 |
C6—H6···O1i | 0.95 | 2.58 | 3.4604 (16) | 155 |
C11—H11···F2ii | 0.95 | 2.66 | 3.2063 (17) | 117 |
C12—H12B···F3iii | 0.99 | 2.37 | 3.3320 (16) | 163 |
C15—H15B···Cgiv | 0.98 | 2.82 | 3.6385 (18) | 141 |
Symmetry codes: (i) −x+2, −y+1, −z; (ii) −x+2, −y+1, −z+1; (iii) x, −y+3/2, z−1/2; (iv) x, y, z−1. |
Triflumizole (systematic name: [(E)-4-chloro-α,α,α-trifluoro- N-(1-imidazol-1-yl-2-propoxyethylidene)-o-toluidine]), is a well known fungicide discoverd by Nippon Soda Co. Ltd., Japan (İnam et al., 2006; Nakata et al., 1991). However it's crystal structure has not been reported yet.
In the title compound (Scheme 1, Fig.1), the dihedral angle between the paniline and imidazole ring planes is 81.80 (4)°. All bond lengths and bond angles of core part consisting of aniline and methylimidazole groups are are comparable to those observed in similar structures (Long et al., 2008).
In the crystal structure, as shown in Fig. 2, weak C—H···X (X = N, O or F) hydrogen bonds are observed (Table 1). Weak intermolecular C—H···π interactions with 3.64 Å also exist. These intermolecular interactions may be contribute to the stabilization of the packing.