organic compounds
N,N′-Bis[(E)-2-fluorobenzylidene]-1-(2-fluorophenyl)methanediamine
aDepartment of Chemistry, Keene State College, 229 Main Street, Keene, NH 03435-2001, USA, bDepartment of Chemistry, Howard University, 525 College Street NW, Washington, DC 20059, USA, cDepartment of Studies in Chemistry, University of Mysore, Manasagangotri, Mysore 570 006, India, and dDepartment of Studies in Chemistry, Mangalore University, Mangalagangotri 574 199, India
*Correspondence e-mail: jjasinski@keene.edu
In the title compound, C21H15F3N2, the benzene ring bonded to the central C atom forms dihedral angles of 77.5 (7) and 89.0 (5)°, respectively, with the remaining two benzene rings. Weak intermolecular C—H⋯F hydrogen bonds link the molecules into chains propagated in [101]. The crystal packing exhibits weak π–π interactions as evidenced by relatively short distances between the centroids of the aromatic rings [3.820 (7) and 3.971 (5) Å]. A MOPAC PM3 optimization of the molecular geometry in vacuo supports a suggestion that intermolecular forces have a significnt influence on the molecular conformation in the crystal.
Related literature
For aromatic aldehyde reactions, see Williams & Bailar (1959). For kinetics of hydrobenzamides, see Crampton et al. (1997). For conventional preparation of hydrobenzamides, see Kamal & Qureshi (1963). For related structures, see: Corey & Kuhnle (1997); Karupaiyan et al. (1998); Saigo et al. (1986). For bond-length data, see: Allen et al. (1987). For the synthesis of nitrogen-containing see Kupfer & Brinker (1996). For MOPAC PM3 calculations, see Schmidt & Polik (2007).
Experimental
Crystal data
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Data collection
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Refinement
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Data collection: CrysAlis PRO (Oxford Diffraction, 2007); cell CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL.
Supporting information
https://doi.org/10.1107/S1600536810001984/cv2683sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810001984/cv2683Isup2.hkl
10 ml of 25% methanolic ammonia was added to a solution of 2 g of 2-flurobenzaldehyde in 10 ml me thanol and left to stand at ambient temperature for 2 days, during which the crystalline products separated out (Fig. 3). The crude crystals were filtered off, washed with cold methanol. Good quality x-ray grade crystals were obtained by the slow evaporation of the solution in ethyl acetate (m.p.: 425–427 K). Analysis for the title compound C21H15F3N2: Found (calculated): C: 71.75 (71.82); H: 4.26 (4.29); N: 7.90 (7.95).
All of the H atoms were placed in their calculated positions and then refined using the riding model with C—H = 0.95 Å, and with Uiso(H) = 1.18–1.20Ueq(C).
Reaction of aromatic
with ammonia leads to the long-known compounds called "hydrobenzamides" (Williams & Bailar, 1959). Owing to their unique structural features and reactivity, these compounds have been recognized as potential key intermediates for the synthesis of a variety of nitrogen containing (Kupfer & Brinker, 1996). Extensive studies on kinetics and mechanism of formation of hydrobenzamides from aromatic and ammonia have been well documented (Crampton et al. 1997). The only conventional method available for the preparation of these compounds involves the reaction of with ammonia, a complex reversible reaction which takes days to weeks for completion (Kamal & Qureshi, 1963). Moreover, protic solvents used in this reaction such as methanol or water enhance the reversible conversion of products into starting thereby reducing the yields even after longer reaction times. Due to the importance of these compounds, we report the of a newly synthesized derivative, C21H15F3N2, (I).The title compound, C21H15F3N2, (I), consists of a 2-fluorophenyl group and a N,N'-bis[(E)-(2-fluorophenyl)methylidene]methanediamine group bonded to a methane carbon, C1 (Fig. 1). The benzene ring bonded to the central methyl carbon atom forms dihedral angles of 77.5 (7)° and 89.0 (5)°, respectively, with the remaining two benzene rings. The dihedral angle between the mean planes of the remaining two benzene rings is 15.7 (7)°. Five of the angles around the methane carbon, C1, are in the vicinity of the 108°-109° range (N1A—C1—C2; 109.45 (11)°, N1B—C1—C2; 108.04 (10)°, C2—C1—H1A; 108.(2)°, N1A—C1—H1A; 108.(2)°, N1B—C1—H1A; 108.(2)°) with only the N1A—C1—N2A angle measuring 114.48 (10)° giving it a slightly distorted sp3 configuration in the direction of the two nitrogen atoms. Bond lengths and bond angles are all within expected ranges (Allen et al., 1987).
Crystal packing is influenced by weak C—H···F intermolecular hydrogen bond interactions which link the molecule into chains propagating obliquely along the c axis in the direction [101] (Fig. 2). In addition, weak Cg2···Cg2 (3.971 (5) Å; -x, 1 - y, -z) and Cg3···Cg3 (3.820 (7) Å; 2 - x, 2 - y, 1 - z) π-π intermolecular interactions are observed with slippage distances of 1.81 (4) Å and 1.76 (5) Å, respectively. (Cg2, Cg3 = ring centroids for C2A—C7A and C2B—C7B, respectively).
In support of these observations, a MOPAC PM3 calculation was performed on the C21H15F3N2, molecule with WebMO Pro (Schmidt & Polik, 2007) (PM3, Parameterized Model 3) approximation together with the Hartree-Fock closed-shell (restricted) wavefunction was used and minimizations were teminnated at an r.m.s. gradient of less than 0.01 kJ mol-1 Å-1.). While the bond distances did not appear to change significantly, selected bond and torsion angles were noticeably different. The bond angle for N1A—C1A—N1B (114.48 (10)° versus 111.3°) is shorter and for C2A—C3A—F1A (117.81 (12)° versus 120.4°) is wider after the calculation. The torsion angles for C1A—N1A—C1—C2 (86.45 (14)° versus 78.17°) and C1B—N1B—C1—C2 (124.39 (13)° versus 96.35°) are both much lower after the calculation indicating a much greater twist causing the two benzene rings to be further apart. This is supported by the PM3 calculated value of 36.79° (versus. 15.7 (7)° before the calculation) for the angle between the mean planes of the two benzene rings. In addition the angles between the mean planes of the two benzene rings with the C1 bonded benzene are 70.22° (versus.77.5 (7)°) and 82.32° (versus. 89.0 (5)°), respectively, after the calculation. This suggests that small changes in some bond distances and selectively in some bond and torsion angles, especially involving the diamine nitrogen atoms have been infuenced by the collective effect of all of the weak intermolecular interactions that have been observed in the crystal packing.
For aromatic aldehyde reactions, see Williams & Bailar (1959). For kinetics of hydrobenzamides, see Crampton et al. (1997). For conventional preparation of hydrobenzamides, see Kamal & Qureshi (1963). For related structures, see: Corey & Kuhnle (1997); Karupaiyan et al. (1998); Saigo et al. (1986). For bond-length data, see: Allen et al. (1987). For the synthesis of nitrogen-containing
see Kupfer & Brinker (1996). For MOPAC PM3 calculations, see Schmidt & Polik (2007). AUTHOR: Fig. 1 is corrupted - please supply new fileData collection: CrysAlis PRO (Oxford Diffraction, 2007); cell
CrysAlis PRO (Oxford Diffraction, 2007); data reduction: CrysAlis PRO (Oxford Diffraction, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).C21H15F3N2 | Z = 2 |
Mr = 352.35 | F(000) = 364 |
Triclinic, P1 | Dx = 1.394 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 8.0215 (5) Å | Cell parameters from 4026 reflections |
b = 9.3740 (4) Å | θ = 4.6–32.4° |
c = 11.9744 (6) Å | µ = 0.11 mm−1 |
α = 99.184 (4)° | T = 200 K |
β = 93.179 (5)° | Prism, colourless |
γ = 108.165 (5)° | 0.49 × 0.29 × 0.22 mm |
V = 839.23 (8) Å3 |
Oxford Diffraction Gemini diffractometer | 3292 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.025 |
Graphite monochromator | θmax = 32.5°, θmin = 4.6° |
Detector resolution: 10.5081 pixels mm-1 | h = −11→12 |
φ and ω scans | k = −14→13 |
11550 measured reflections | l = −16→17 |
5484 independent reflections |
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)] = 0.052 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.152 | H-atom parameters constrained |
S = 1.00 | w = 1/[σ2(Fo2) + (0.0841P)2] where P = (Fo2 + 2Fc2)/3 |
5484 reflections | (Δ/σ)max < 0.001 |
235 parameters | Δρmax = 0.57 e Å−3 |
0 restraints | Δρmin = −0.20 e Å−3 |
C21H15F3N2 | γ = 108.165 (5)° |
Mr = 352.35 | V = 839.23 (8) Å3 |
Triclinic, P1 | Z = 2 |
a = 8.0215 (5) Å | Mo Kα radiation |
b = 9.3740 (4) Å | µ = 0.11 mm−1 |
c = 11.9744 (6) Å | T = 200 K |
α = 99.184 (4)° | 0.49 × 0.29 × 0.22 mm |
β = 93.179 (5)° |
Oxford Diffraction Gemini diffractometer | 3292 reflections with I > 2σ(I) |
11550 measured reflections | Rint = 0.025 |
5484 independent reflections |
R[F2 > 2σ(F2)] = 0.052 | 0 restraints |
wR(F2) = 0.152 | H-atom parameters constrained |
S = 1.00 | Δρmax = 0.57 e Å−3 |
5484 reflections | Δρmin = −0.20 e Å−3 |
235 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 | ||
F1 | 0.62912 (14) | 1.01485 (11) | 0.09363 (8) | 0.0596 (3) | |
F1A | 0.21867 (14) | 0.54600 (10) | −0.14842 (7) | 0.0511 (3) | |
F1B | 0.62463 (12) | 0.41513 (8) | 0.48075 (7) | 0.0434 (2) | |
N1A | 0.43939 (15) | 0.62936 (12) | 0.17778 (9) | 0.0315 (3) | |
N1B | 0.70316 (15) | 0.77388 (12) | 0.31351 (9) | 0.0314 (3) | |
C1 | 0.58583 (18) | 0.77356 (14) | 0.21571 (11) | 0.0297 (3) | |
H1A | 0.6576 | 0.7941 | 0.1509 | 0.036* | |
C2 | 0.51189 (17) | 0.90345 (13) | 0.24663 (10) | 0.0282 (3) | |
C3 | 0.53477 (19) | 1.01805 (15) | 0.18400 (11) | 0.0344 (3) | |
C4 | 0.4682 (2) | 1.13682 (16) | 0.20930 (13) | 0.0424 (4) | |
H4A | 0.4871 | 1.2137 | 0.1640 | 0.051* | |
C5 | 0.3733 (2) | 1.14203 (16) | 0.30200 (13) | 0.0427 (4) | |
H5A | 0.3249 | 1.2222 | 0.3203 | 0.051* | |
C6 | 0.3491 (2) | 1.03019 (16) | 0.36807 (12) | 0.0404 (3) | |
H6A | 0.2855 | 1.0345 | 0.4324 | 0.049* | |
C7 | 0.4174 (2) | 0.91224 (15) | 0.34048 (11) | 0.0348 (3) | |
H7A | 0.3997 | 0.8359 | 0.3862 | 0.042* | |
C1A | 0.38045 (18) | 0.59817 (14) | 0.07361 (10) | 0.0284 (3) | |
H1AA | 0.4326 | 0.6673 | 0.0256 | 0.034* | |
C2A | 0.23439 (17) | 0.45892 (13) | 0.02440 (10) | 0.0269 (3) | |
C3A | 0.15517 (19) | 0.43569 (15) | −0.08628 (11) | 0.0325 (3) | |
C4A | 0.0176 (2) | 0.30824 (17) | −0.13529 (12) | 0.0411 (4) | |
H4AA | −0.0330 | 0.2975 | −0.2111 | 0.049* | |
C5A | −0.0459 (2) | 0.19599 (17) | −0.07250 (14) | 0.0479 (4) | |
H5AA | −0.1414 | 0.1067 | −0.1050 | 0.057* | |
C6A | 0.0291 (2) | 0.21259 (16) | 0.03835 (13) | 0.0468 (4) | |
H6AA | −0.0148 | 0.1346 | 0.0813 | 0.056* | |
C7A | 0.1674 (2) | 0.34260 (15) | 0.08573 (11) | 0.0361 (3) | |
H7AA | 0.2180 | 0.3532 | 0.1615 | 0.043* | |
C1B | 0.67867 (17) | 0.65547 (14) | 0.35664 (10) | 0.0281 (3) | |
H1BA | 0.5831 | 0.5652 | 0.3263 | 0.034* | |
C2B | 0.80098 (17) | 0.65923 (13) | 0.45521 (10) | 0.0276 (3) | |
C3B | 0.76856 (18) | 0.54090 (14) | 0.51567 (11) | 0.0305 (3) | |
C4B | 0.8769 (2) | 0.54521 (16) | 0.61103 (12) | 0.0367 (3) | |
H4BA | 0.8495 | 0.4630 | 0.6515 | 0.044* | |
C5B | 1.0254 (2) | 0.67148 (17) | 0.64619 (12) | 0.0409 (4) | |
H5BA | 1.1014 | 0.6764 | 0.7115 | 0.049* | |
C6B | 1.0645 (2) | 0.79119 (16) | 0.58684 (12) | 0.0408 (4) | |
H6BA | 1.1675 | 0.8775 | 0.6110 | 0.049* | |
C7B | 0.95321 (19) | 0.78464 (14) | 0.49220 (11) | 0.0335 (3) | |
H7BA | 0.9809 | 0.8669 | 0.4518 | 0.040* |
U11 | U22 | U33 | U12 | U13 | U23 | |
F1 | 0.0633 (7) | 0.0747 (7) | 0.0551 (6) | 0.0276 (6) | 0.0245 (5) | 0.0366 (5) |
F1A | 0.0650 (7) | 0.0515 (5) | 0.0334 (4) | 0.0138 (5) | −0.0069 (4) | 0.0125 (4) |
F1B | 0.0381 (5) | 0.0310 (4) | 0.0537 (5) | 0.0007 (4) | 0.0004 (4) | 0.0093 (4) |
N1A | 0.0280 (6) | 0.0319 (5) | 0.0289 (5) | 0.0041 (5) | −0.0036 (5) | 0.0032 (4) |
N1B | 0.0261 (6) | 0.0322 (5) | 0.0328 (5) | 0.0068 (5) | −0.0042 (5) | 0.0047 (4) |
C1 | 0.0253 (7) | 0.0308 (6) | 0.0286 (6) | 0.0035 (5) | −0.0018 (5) | 0.0056 (5) |
C2 | 0.0223 (6) | 0.0282 (6) | 0.0279 (6) | 0.0011 (5) | −0.0053 (5) | 0.0043 (5) |
C3 | 0.0288 (7) | 0.0393 (7) | 0.0314 (6) | 0.0039 (6) | 0.0012 (6) | 0.0117 (6) |
C4 | 0.0439 (9) | 0.0345 (7) | 0.0473 (8) | 0.0078 (7) | −0.0039 (7) | 0.0168 (6) |
C5 | 0.0429 (9) | 0.0327 (7) | 0.0489 (8) | 0.0125 (6) | −0.0068 (7) | 0.0008 (6) |
C6 | 0.0397 (9) | 0.0411 (7) | 0.0363 (7) | 0.0101 (7) | 0.0041 (6) | 0.0016 (6) |
C7 | 0.0379 (8) | 0.0317 (6) | 0.0317 (6) | 0.0062 (6) | 0.0030 (6) | 0.0081 (5) |
C1A | 0.0271 (7) | 0.0291 (6) | 0.0282 (6) | 0.0082 (5) | 0.0020 (5) | 0.0056 (5) |
C2A | 0.0252 (7) | 0.0280 (6) | 0.0266 (6) | 0.0106 (5) | 0.0001 (5) | −0.0001 (5) |
C3A | 0.0327 (8) | 0.0361 (7) | 0.0294 (6) | 0.0146 (6) | −0.0004 (6) | 0.0023 (5) |
C4A | 0.0330 (8) | 0.0471 (8) | 0.0371 (7) | 0.0152 (7) | −0.0087 (6) | −0.0097 (6) |
C5A | 0.0316 (8) | 0.0408 (8) | 0.0581 (10) | 0.0038 (7) | −0.0024 (7) | −0.0103 (7) |
C6A | 0.0441 (10) | 0.0343 (7) | 0.0544 (9) | 0.0031 (7) | 0.0059 (8) | 0.0062 (7) |
C7A | 0.0372 (8) | 0.0360 (7) | 0.0326 (7) | 0.0095 (6) | 0.0015 (6) | 0.0051 (5) |
C1B | 0.0236 (7) | 0.0283 (6) | 0.0282 (6) | 0.0052 (5) | 0.0004 (5) | 0.0002 (5) |
C2B | 0.0249 (7) | 0.0278 (6) | 0.0277 (6) | 0.0080 (5) | −0.0003 (5) | 0.0008 (5) |
C3B | 0.0278 (7) | 0.0264 (6) | 0.0345 (6) | 0.0066 (5) | 0.0037 (6) | 0.0022 (5) |
C4B | 0.0420 (9) | 0.0373 (7) | 0.0360 (7) | 0.0171 (7) | 0.0054 (6) | 0.0126 (6) |
C5B | 0.0406 (9) | 0.0509 (8) | 0.0327 (7) | 0.0182 (7) | −0.0042 (6) | 0.0077 (6) |
C6B | 0.0325 (8) | 0.0401 (7) | 0.0413 (7) | 0.0041 (6) | −0.0087 (6) | 0.0033 (6) |
C7B | 0.0306 (7) | 0.0295 (6) | 0.0368 (7) | 0.0055 (6) | −0.0025 (6) | 0.0064 (5) |
F1—C3 | 1.3562 (16) | C2A—C7A | 1.3968 (18) |
F1A—C3A | 1.3571 (16) | C3A—C4A | 1.3681 (19) |
F1B—C3B | 1.3558 (15) | C4A—C5A | 1.376 (2) |
N1A—C1A | 1.2637 (15) | C4A—H4AA | 0.9500 |
N1A—C1 | 1.4725 (16) | C5A—C6A | 1.391 (2) |
N1B—C1B | 1.2632 (15) | C5A—H5AA | 0.9500 |
N1B—C1 | 1.4602 (16) | C6A—C7A | 1.380 (2) |
C1—C2 | 1.5173 (18) | C6A—H6AA | 0.9500 |
C1—H1A | 1.0000 | C7A—H7AA | 0.9500 |
C2—C3 | 1.3782 (18) | C1B—C2B | 1.4811 (17) |
C2—C7 | 1.3958 (19) | C1B—H1BA | 0.9500 |
C3—C4 | 1.377 (2) | C2B—C3B | 1.3856 (17) |
C4—C5 | 1.383 (2) | C2B—C7B | 1.3957 (17) |
C4—H4A | 0.9500 | C3B—C4B | 1.3833 (18) |
C5—C6 | 1.385 (2) | C4B—C5B | 1.380 (2) |
C5—H5A | 0.9500 | C4B—H4BA | 0.9500 |
C6—C7 | 1.383 (2) | C5B—C6B | 1.387 (2) |
C6—H6A | 0.9500 | C5B—H5BA | 0.9500 |
C7—H7A | 0.9500 | C6B—C7B | 1.3846 (18) |
C1A—C2A | 1.4656 (17) | C6B—H6BA | 0.9500 |
C1A—H1AA | 0.9500 | C7B—H7BA | 0.9500 |
C2A—C3A | 1.3914 (16) | ||
C1A—N1A—C1 | 116.40 (11) | C4A—C3A—C2A | 123.58 (13) |
C1B—N1B—C1 | 120.47 (10) | C3A—C4A—C5A | 118.57 (13) |
N1B—C1—N1A | 114.48 (10) | C3A—C4A—H4AA | 120.7 |
N1B—C1—C2 | 108.04 (10) | C5A—C4A—H4AA | 120.7 |
N1A—C1—C2 | 109.45 (11) | C4A—C5A—C6A | 120.35 (13) |
N1B—C1—H1A | 108.2 | C4A—C5A—H5AA | 119.8 |
N1A—C1—H1A | 108.2 | C6A—C5A—H5AA | 119.8 |
C2—C1—H1A | 108.2 | C7A—C6A—C5A | 119.82 (14) |
C3—C2—C7 | 116.89 (12) | C7A—C6A—H6AA | 120.1 |
C3—C2—C1 | 121.87 (12) | C5A—C6A—H6AA | 120.1 |
C7—C2—C1 | 121.24 (11) | C6A—C7A—C2A | 121.23 (12) |
F1—C3—C4 | 118.24 (12) | C6A—C7A—H7AA | 119.4 |
F1—C3—C2 | 118.47 (13) | C2A—C7A—H7AA | 119.4 |
C4—C3—C2 | 123.29 (13) | N1B—C1B—C2B | 119.11 (11) |
C3—C4—C5 | 118.71 (13) | N1B—C1B—H1BA | 120.4 |
C3—C4—H4A | 120.6 | C2B—C1B—H1BA | 120.4 |
C5—C4—H4A | 120.6 | C3B—C2B—C7B | 117.18 (11) |
C4—C5—C6 | 119.87 (14) | C3B—C2B—C1B | 121.92 (11) |
C4—C5—H5A | 120.1 | C7B—C2B—C1B | 120.89 (11) |
C6—C5—H5A | 120.1 | F1B—C3B—C4B | 118.11 (12) |
C7—C6—C5 | 120.09 (14) | F1B—C3B—C2B | 119.07 (11) |
C7—C6—H6A | 120.0 | C4B—C3B—C2B | 122.82 (12) |
C5—C6—H6A | 120.0 | C5B—C4B—C3B | 118.61 (13) |
C6—C7—C2 | 121.14 (13) | C5B—C4B—H4BA | 120.7 |
C6—C7—H7A | 119.4 | C3B—C4B—H4BA | 120.7 |
C2—C7—H7A | 119.4 | C4B—C5B—C6B | 120.43 (12) |
N1A—C1A—C2A | 122.22 (12) | C4B—C5B—H5BA | 119.8 |
N1A—C1A—H1AA | 118.9 | C6B—C5B—H5BA | 119.8 |
C2A—C1A—H1AA | 118.9 | C7B—C6B—C5B | 119.84 (13) |
C3A—C2A—C7A | 116.45 (12) | C7B—C6B—H6BA | 120.1 |
C3A—C2A—C1A | 121.58 (11) | C5B—C6B—H6BA | 120.1 |
C7A—C2A—C1A | 121.97 (11) | C6B—C7B—C2B | 121.11 (12) |
F1A—C3A—C4A | 118.62 (11) | C6B—C7B—H7BA | 119.4 |
F1A—C3A—C2A | 117.81 (12) | C2B—C7B—H7BA | 119.4 |
C1B—N1B—C1—N1A | 2.17 (18) | C7A—C2A—C3A—C4A | 0.7 (2) |
C1B—N1B—C1—C2 | 124.39 (13) | C1A—C2A—C3A—C4A | −179.39 (13) |
C1A—N1A—C1—N1B | −152.10 (12) | F1A—C3A—C4A—C5A | 179.56 (13) |
C1A—N1A—C1—C2 | 86.45 (14) | C2A—C3A—C4A—C5A | −0.4 (2) |
N1B—C1—C2—C3 | 122.02 (13) | C3A—C4A—C5A—C6A | −0.1 (2) |
N1A—C1—C2—C3 | −112.72 (13) | C4A—C5A—C6A—C7A | 0.2 (2) |
N1B—C1—C2—C7 | −57.86 (15) | C5A—C6A—C7A—C2A | 0.0 (2) |
N1A—C1—C2—C7 | 67.40 (14) | C3A—C2A—C7A—C6A | −0.5 (2) |
C7—C2—C3—F1 | 178.64 (11) | C1A—C2A—C7A—C6A | 179.60 (14) |
C1—C2—C3—F1 | −1.25 (18) | C1—N1B—C1B—C2B | 179.50 (12) |
C7—C2—C3—C4 | −0.6 (2) | N1B—C1B—C2B—C3B | 171.37 (12) |
C1—C2—C3—C4 | 179.50 (13) | N1B—C1B—C2B—C7B | −7.51 (19) |
F1—C3—C4—C5 | −179.35 (13) | C7B—C2B—C3B—F1B | −178.25 (12) |
C2—C3—C4—C5 | −0.1 (2) | C1B—C2B—C3B—F1B | 2.83 (19) |
C3—C4—C5—C6 | 0.9 (2) | C7B—C2B—C3B—C4B | 1.9 (2) |
C4—C5—C6—C7 | −0.9 (2) | C1B—C2B—C3B—C4B | −177.00 (13) |
C5—C6—C7—C2 | 0.2 (2) | F1B—C3B—C4B—C5B | 178.88 (12) |
C3—C2—C7—C6 | 0.54 (19) | C2B—C3B—C4B—C5B | −1.3 (2) |
C1—C2—C7—C6 | −179.57 (12) | C3B—C4B—C5B—C6B | 0.0 (2) |
C1—N1A—C1A—C2A | −179.66 (11) | C4B—C5B—C6B—C7B | 0.5 (2) |
N1A—C1A—C2A—C3A | 171.24 (13) | C5B—C6B—C7B—C2B | 0.2 (2) |
N1A—C1A—C2A—C7A | −8.8 (2) | C3B—C2B—C7B—C6B | −1.3 (2) |
C7A—C2A—C3A—F1A | −179.31 (12) | C1B—C2B—C7B—C6B | 177.59 (13) |
C1A—C2A—C3A—F1A | 0.63 (19) |
D—H···A | D—H | H···A | D···A | D—H···A |
C5B—H5BA···F1Ai | 0.95 | 2.53 | 3.3871 (16) | 151 |
Symmetry code: (i) x+1, y, z+1. |
Experimental details
Crystal data | |
Chemical formula | C21H15F3N2 |
Mr | 352.35 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 200 |
a, b, c (Å) | 8.0215 (5), 9.3740 (4), 11.9744 (6) |
α, β, γ (°) | 99.184 (4), 93.179 (5), 108.165 (5) |
V (Å3) | 839.23 (8) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.11 |
Crystal size (mm) | 0.49 × 0.29 × 0.22 |
Data collection | |
Diffractometer | Oxford Diffraction Gemini |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 11550, 5484, 3292 |
Rint | 0.025 |
(sin θ/λ)max (Å−1) | 0.756 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.052, 0.152, 1.00 |
No. of reflections | 5484 |
No. of parameters | 235 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.57, −0.20 |
Computer programs: CrysAlis PRO (Oxford Diffraction, 2007), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).
D—H···A | D—H | H···A | D···A | D—H···A |
C5B—H5BA···F1Ai | 0.95 | 2.53 | 3.3871 (16) | 150.5 |
Symmetry code: (i) x+1, y, z+1. |
Acknowledgements
QNMHA thanks the University of Mysore for use of their research facilities. RJB acknowledges the NSF MRI program (grant No. CHE-0619278) for funds to purchase an X-ray diffractometer.
References
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This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
Reaction of aromatic aldehydes with ammonia leads to the long-known compounds called "hydrobenzamides" (Williams & Bailar, 1959). Owing to their unique structural features and reactivity, these compounds have been recognized as potential key intermediates for the synthesis of a variety of nitrogen containing heterocyclic compounds (Kupfer & Brinker, 1996). Extensive studies on kinetics and mechanism of formation of hydrobenzamides from aromatic aldehydes and ammonia have been well documented (Crampton et al. 1997). The only conventional method available for the preparation of these compounds involves the reaction of aldehydes with ammonia, a complex reversible reaction which takes days to weeks for completion (Kamal & Qureshi, 1963). Moreover, protic solvents used in this reaction such as methanol or water enhance the reversible conversion of products into starting aldehydes, thereby reducing the yields even after longer reaction times. Due to the importance of these compounds, we report the crystal structure of a newly synthesized derivative, C21H15F3N2, (I).
The title compound, C21H15F3N2, (I), consists of a 2-fluorophenyl group and a N,N'-bis[(E)-(2-fluorophenyl)methylidene]methanediamine group bonded to a methane carbon, C1 (Fig. 1). The benzene ring bonded to the central methyl carbon atom forms dihedral angles of 77.5 (7)° and 89.0 (5)°, respectively, with the remaining two benzene rings. The dihedral angle between the mean planes of the remaining two benzene rings is 15.7 (7)°. Five of the angles around the methane carbon, C1, are in the vicinity of the 108°-109° range (N1A—C1—C2; 109.45 (11)°, N1B—C1—C2; 108.04 (10)°, C2—C1—H1A; 108.(2)°, N1A—C1—H1A; 108.(2)°, N1B—C1—H1A; 108.(2)°) with only the N1A—C1—N2A angle measuring 114.48 (10)° giving it a slightly distorted sp3 configuration in the direction of the two nitrogen atoms. Bond lengths and bond angles are all within expected ranges (Allen et al., 1987).
Crystal packing is influenced by weak C—H···F intermolecular hydrogen bond interactions which link the molecule into chains propagating obliquely along the c axis in the direction [101] (Fig. 2). In addition, weak Cg2···Cg2 (3.971 (5) Å; -x, 1 - y, -z) and Cg3···Cg3 (3.820 (7) Å; 2 - x, 2 - y, 1 - z) π-π intermolecular interactions are observed with slippage distances of 1.81 (4) Å and 1.76 (5) Å, respectively. (Cg2, Cg3 = ring centroids for C2A—C7A and C2B—C7B, respectively).
In support of these observations, a MOPAC PM3 calculation was performed on the C21H15F3N2, molecule with WebMO Pro (Schmidt & Polik, 2007) (PM3, Parameterized Model 3) approximation together with the Hartree-Fock closed-shell (restricted) wavefunction was used and minimizations were teminnated at an r.m.s. gradient of less than 0.01 kJ mol-1 Å-1.). While the bond distances did not appear to change significantly, selected bond and torsion angles were noticeably different. The bond angle for N1A—C1A—N1B (114.48 (10)° versus 111.3°) is shorter and for C2A—C3A—F1A (117.81 (12)° versus 120.4°) is wider after the calculation. The torsion angles for C1A—N1A—C1—C2 (86.45 (14)° versus 78.17°) and C1B—N1B—C1—C2 (124.39 (13)° versus 96.35°) are both much lower after the calculation indicating a much greater twist causing the two benzene rings to be further apart. This is supported by the PM3 calculated value of 36.79° (versus. 15.7 (7)° before the calculation) for the angle between the mean planes of the two benzene rings. In addition the angles between the mean planes of the two benzene rings with the C1 bonded benzene are 70.22° (versus.77.5 (7)°) and 82.32° (versus. 89.0 (5)°), respectively, after the calculation. This suggests that small changes in some bond distances and selectively in some bond and torsion angles, especially involving the diamine nitrogen atoms have been infuenced by the collective effect of all of the weak intermolecular interactions that have been observed in the crystal packing.