organic compounds
meso-4,4′-Difluoro-2,2′-{[(3aR,7aS)-2,3,3a,4,5,6,7,7a-octahydro-1H-1,3-benzimidazole-1,3-diyl]bis(methylene)}diphenol
aFacultad de Ciencias, Departamento de Química, Universidad Nacional de Colombia, Sede Bogotá, Cra 30 No. 45-03, Bogotá, Código Postal 111321, Colombia, and bInstitute of Physics, Academy of Sciences of the Czech Republic, v.v.i., Na Slovance 2, 182 21 Praha 8, Czech Republic
*Correspondence e-mail: ariverau@unal.edu.co
In the 21H24F2N2O2, there are two intramolecular O—H⋯N hydrogen bonds involving the N atoms of the imidazolidine ring and the hydroxy groups. The crystal studied was a meso compound obtained by the reaction of the aminal (2S,7R,11S,16R)-1,8,10,17-tetraazapentacyclo[8.8.1.18,17.02,7.011,16]cosane with 4-fluorophenol. The imidazolidine ring has a twisted conformation with a CH—CH—N—CH2 torsion angle of 44.99 (14)° and, surprisingly, the lone pairs of the N atoms are disposed in a syn making the title compound an exception to the typical `rabbit-ear effect' in 1,2-diamines. In the crystal, molecules are linked via C—H⋯F hydrogen bonds, forming chains along the c-axis direction. These chains are linked via another C—H⋯F hydrogen bond, forming a three-dimensional network.
of the title compound, CRelated literature
For a related structure, see: Rivera et al. (2011). For a discussion of the `rabbit-ear effect' in 1,2-diamines, see: Hutchins et al.(1968).
Experimental
Crystal data
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Refinement
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Data collection: CrysAlis PRO (Agilent, 2010); cell CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SUPERFLIP (Palatinus & Chapuis, 2007); program(s) used to refine structure: JANA2006 (Petříček et al., 2006); molecular graphics: DIAMOND (Brandenburg & Putz, 2005); software used to prepare material for publication: JANA2006.
Supporting information
10.1107/S1600536813000305/bx2435sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536813000305/bx2435Isup2.hkl
Supporting information file. DOI: 10.1107/S1600536813000305/bx2435Isup3.cml
To a stirred solution of (2S,7R,11S,16R)-1,8,10,17-tetraazapentacyclo[8.8.1.1.8,170.2,7011,16] icosane (3) (276 mg, 1.00 mmol) in dioxane (3 ml) was added slowly dropwise p-fluorophenol (2.00 mmol) in dioxane (3 ml). After stirring for 15 min at room temperature, water (4 ml) was added and the mixture was heated at 40°C during 30 h. After cooling to room temperature, the solvent was removed in vacuo and the crude product was purified by νmax: 3061, 2848, 1495, 1448, 1387, 1289, 1245, 1194, 1124, 1063, 979, 925, 814, 772, 737, 714, 692, 668 cm-1. 1H NMR (400 MHz, CDCl3) δ (p.p.m.): 1.36 (m, 2H), 1.55–1.79 (m, 6H), 3.11 (t, 2H, JH,H = 4.0 Hz), 3.39 (d, 1H,2JH,H = 6.4 Hz, NCH2N), 3.63 (d, 2H, 2JH,H = 14.0 Hz, ArCH2N), 3.84 (d, 1H, 2JH,H = 6.4 Hz, NCH2N), 4.03 (d, 2H, 2JH,H = 14.0 Hz, ArCH2N), 6.70 (dd, 2H, 3JH,F = 8.0 Hz, 4JH,H = 2.8 Hz, Ar—H), 6.76 (dd, 2H, 3JH,H = 8.0 Hz, 4JH,F = 4.8 Hz, Ar—H), 6.87 (td, 2H, 3JH,H = 8.0 Hz, 3JH,F = 8.2 Hz, 4JH,H = 3.1 Hz, Ar—H), 10.34 (s, 2H). 13C NMR (100 MHz, CDCl3) δ (p.p.m.): 21.5, 24.7, 55.0, 61.1, 73.4, 114.7 (d, 2JH,F = 23.5 Hz), 115.4 (d, 2JH,F = 22.5 Hz), 117.0 (d, 3JH,F = 6.3 Hz), 122.0 (d, 3JH,F = 6.9 Hz), 153.4 (d, 4JH,F = 2.0 Hz), 156.0 (d, 1JH,F = 236 Hz).
on a silica column and subjected to with light petroleum ether:ethyl acetate (yield 20%, m.p. = 441–443 K). Single crystals of (I) were grown from a CHCl3 solution by slow evaporation of the solvent at room temperature over a period of about 2 weeks. FT–IR (KBr)All H atoms were discernible in difference Fourier maps and could be refined to reasonable geometry. According to common practice H atoms bonded C atoms were kept in ideal positions with C—H distance 0.96 Å during the
The hydroxy H atoms were found in difference Fourier maps and their coordinates were refined freely. All H atoms were refined with thermal displacement coefficients Uiso(H) set to 1.5Ueq(C, O) for hydroxy groups and to 1.2Ueq(C) for the CH– and CH2– groups.Data collection: CrysAlis PRO (Agilent, 2010); cell
CrysAlis PRO (Agilent, 2010); data reduction: CrysAlis PRO (Agilent, 2010); program(s) used to solve structure: SUPERFLIP (Palatinus & Chapuis, 2007); program(s) used to refine structure: JANA2006 (Petříček et al., 2006); molecular graphics: DIAMOND (Brandenburg & Putz, 2005); software used to prepare material for publication: JANA2006 (Petříček et al., 2006).C21H24F2N2O2 | F(000) = 792 |
Mr = 374.4 | Dx = 1.394 Mg m−3 |
Orthorhombic, Pna21 | Cu Kα radiation, λ = 1.5418 Å |
Hall symbol: P -2ac -2n | Cell parameters from 19583 reflections |
a = 15.4029 (4) Å | θ = 3.7–67.0° |
b = 18.7822 (4) Å | µ = 0.86 mm−1 |
c = 6.1639 (2) Å | T = 120 K |
V = 1783.22 (8) Å3 | Polygon shape, white |
Z = 4 | 0.31 × 0.15 × 0.11 mm |
Agilent Xcalibur (Atlas, Gemini ultra) diffractometer | 3177 independent reflections |
Radiation source: Enhance Ultra (Cu) X-ray Source | 2984 reflections with I > 3σ(I) |
Mirror monochromator | Rint = 0.049 |
Detector resolution: 10.3784 pixels mm-1 | θmax = 67.1°, θmin = 3.7° |
ω scans | h = −18→18 |
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2010) | k = −22→22 |
Tmin = 0.222, Tmax = 1 | l = −7→7 |
40310 measured reflections |
Refinement on F2 | 91 constraints |
R[F2 > 2σ(F2)] = 0.030 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.077 | Weighting scheme based on measured s.u.'s w = 1/(σ2(I) + 0.0016I2) |
S = 1.42 | (Δ/σ)max = 0.010 |
3177 reflections | Δρmax = 0.15 e Å−3 |
250 parameters | Δρmin = −0.11 e Å−3 |
0 restraints |
C21H24F2N2O2 | V = 1783.22 (8) Å3 |
Mr = 374.4 | Z = 4 |
Orthorhombic, Pna21 | Cu Kα radiation |
a = 15.4029 (4) Å | µ = 0.86 mm−1 |
b = 18.7822 (4) Å | T = 120 K |
c = 6.1639 (2) Å | 0.31 × 0.15 × 0.11 mm |
Agilent Xcalibur (Atlas, Gemini ultra) diffractometer | 3177 independent reflections |
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2010) | 2984 reflections with I > 3σ(I) |
Tmin = 0.222, Tmax = 1 | Rint = 0.049 |
40310 measured reflections |
R[F2 > 2σ(F2)] = 0.030 | 0 restraints |
wR(F2) = 0.077 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.42 | Δρmax = 0.15 e Å−3 |
3177 reflections | Δρmin = −0.11 e Å−3 |
250 parameters |
Refinement. The refinement was carried out against all reflections. The conventional R-factor is always based on F. The goodness of fit as well as the weighted R-factor are based on F and F2 for refinement carried out on F and F2, respectively. The threshold expression is used only for calculating R-factors etc. and it is not relevant to the choice of reflections for refinement. The program used for refinement, Jana2006, uses the weighting scheme based on the experimental expectations, see _refine_ls_weighting_details, that does not force S to be one. Therefore the values of S are usually larger than the ones from the SHELX program. |
x | y | z | Uiso*/Ueq | ||
F1 | 0.08421 (6) | 0.56542 (5) | 0.39265 (19) | 0.0421 (3) | |
F2 | 0.01983 (7) | 0.08785 (5) | −0.0670 (2) | 0.0464 (3) | |
O1 | 0.26711 (8) | 0.11965 (6) | 0.5638 (2) | 0.0355 (4) | |
O2 | 0.25923 (8) | 0.37737 (7) | 0.9132 (2) | 0.0369 (4) | |
N1 | 0.33271 (8) | 0.22874 (7) | 0.3446 (2) | 0.0231 (3) | |
N2 | 0.34150 (7) | 0.33314 (6) | 0.5557 (2) | 0.0238 (4) | |
C1 | 0.20351 (10) | 0.48809 (8) | 0.4427 (3) | 0.0283 (5) | |
C2 | 0.24882 (10) | 0.44012 (8) | 0.5731 (3) | 0.0257 (4) | |
C3 | 0.41911 (9) | 0.26109 (8) | 0.3064 (2) | 0.0230 (4) | |
C4 | 0.33424 (10) | 0.40923 (8) | 0.4988 (3) | 0.0270 (4) | |
C5 | 0.20680 (10) | 0.11405 (8) | 0.4035 (3) | 0.0274 (4) | |
C6 | 0.12823 (10) | 0.51814 (8) | 0.5218 (3) | 0.0314 (5) | |
C7 | 0.21420 (10) | 0.15102 (8) | 0.2071 (3) | 0.0254 (4) | |
C8 | 0.42966 (9) | 0.30360 (8) | 0.5158 (3) | 0.0237 (4) | |
C9 | 0.49248 (9) | 0.20825 (8) | 0.2612 (3) | 0.0267 (4) | |
C10 | 0.08186 (11) | 0.09680 (8) | 0.0901 (3) | 0.0324 (5) | |
C11 | 0.52047 (10) | 0.16567 (8) | 0.4592 (3) | 0.0299 (5) | |
C12 | 0.21650 (10) | 0.42368 (8) | 0.7793 (3) | 0.0289 (5) | |
C13 | 0.07318 (10) | 0.06018 (9) | 0.2813 (3) | 0.0343 (5) | |
C14 | 0.13982 (11) | 0.45439 (9) | 0.8526 (3) | 0.0333 (5) | |
C15 | 0.29291 (10) | 0.19587 (8) | 0.1527 (3) | 0.0259 (4) | |
C16 | 0.09529 (11) | 0.50248 (9) | 0.7232 (3) | 0.0340 (5) | |
C17 | 0.45886 (10) | 0.25765 (9) | 0.7059 (3) | 0.0275 (5) | |
C18 | 0.15019 (10) | 0.14217 (8) | 0.0499 (3) | 0.0284 (4) | |
C19 | 0.13591 (10) | 0.06908 (8) | 0.4391 (3) | 0.0331 (5) | |
C20 | 0.28071 (9) | 0.28869 (8) | 0.4282 (3) | 0.0270 (4) | |
C21 | 0.54005 (11) | 0.21507 (9) | 0.6489 (3) | 0.0321 (5) | |
H1c1 | 0.22435 | 0.499969 | 0.300447 | 0.034* | |
H1c3 | 0.422455 | 0.288956 | 0.176142 | 0.0276* | |
H1c4 | 0.339534 | 0.414724 | 0.344506 | 0.0325* | |
H2c4 | 0.381123 | 0.435124 | 0.564372 | 0.0325* | |
H1c8 | 0.473781 | 0.33942 | 0.502131 | 0.0284* | |
H1c9 | 0.541614 | 0.233235 | 0.203 | 0.032* | |
H2c9 | 0.475105 | 0.176214 | 0.147852 | 0.032* | |
H1c11 | 0.475029 | 0.133249 | 0.499311 | 0.0359* | |
H2c11 | 0.571355 | 0.138428 | 0.424659 | 0.0359* | |
H1c13 | 0.024629 | 0.029077 | 0.30491 | 0.0412* | |
H1c14 | 0.117621 | 0.442274 | 0.993384 | 0.0399* | |
H1c15 | 0.335179 | 0.167023 | 0.079409 | 0.0311* | |
H2c15 | 0.276748 | 0.23231 | 0.051253 | 0.0311* | |
H1c16 | 0.042627 | 0.524324 | 0.773234 | 0.0408* | |
H1c17 | 0.412966 | 0.225597 | 0.745425 | 0.033* | |
H2c17 | 0.470585 | 0.287446 | 0.828962 | 0.033* | |
H1c18 | 0.153672 | 0.167458 | −0.08517 | 0.0341* | |
H1c19 | 0.13078 | 0.044152 | 0.574433 | 0.0397* | |
H1c20 | 0.235882 | 0.270824 | 0.521692 | 0.0324* | |
H2c20 | 0.258396 | 0.315914 | 0.308761 | 0.0324* | |
H1c21 | 0.585954 | 0.24712 | 0.60938 | 0.0386* | |
H2c21 | 0.557641 | 0.187359 | 0.772163 | 0.0386* | |
H1 | 0.3046 (14) | 0.1501 (12) | 0.523 (4) | 0.0426* | |
H2 | 0.2959 (14) | 0.3567 (12) | 0.832 (4) | 0.0443* |
U11 | U22 | U33 | U12 | U13 | U23 | |
F1 | 0.0366 (5) | 0.0315 (5) | 0.0583 (7) | 0.0066 (4) | −0.0117 (5) | 0.0030 (5) |
F2 | 0.0397 (5) | 0.0393 (5) | 0.0602 (7) | −0.0079 (4) | −0.0155 (5) | −0.0076 (5) |
O1 | 0.0400 (6) | 0.0352 (6) | 0.0312 (6) | −0.0068 (5) | −0.0009 (5) | 0.0091 (5) |
O2 | 0.0452 (7) | 0.0398 (7) | 0.0259 (6) | 0.0104 (5) | 0.0049 (6) | 0.0029 (5) |
N1 | 0.0233 (6) | 0.0226 (6) | 0.0234 (6) | −0.0014 (5) | 0.0034 (5) | −0.0016 (5) |
N2 | 0.0231 (6) | 0.0199 (6) | 0.0285 (7) | 0.0004 (5) | 0.0028 (5) | −0.0003 (5) |
C1 | 0.0308 (8) | 0.0214 (7) | 0.0328 (9) | −0.0035 (6) | −0.0036 (7) | 0.0010 (6) |
C2 | 0.0293 (7) | 0.0185 (7) | 0.0292 (8) | −0.0026 (6) | −0.0007 (7) | −0.0035 (6) |
C3 | 0.0240 (7) | 0.0227 (7) | 0.0224 (8) | −0.0007 (6) | 0.0037 (6) | 0.0024 (6) |
C4 | 0.0304 (7) | 0.0203 (7) | 0.0304 (9) | −0.0002 (6) | 0.0035 (6) | 0.0009 (6) |
C5 | 0.0292 (7) | 0.0220 (7) | 0.0311 (8) | 0.0018 (6) | 0.0045 (7) | 0.0006 (6) |
C6 | 0.0294 (8) | 0.0208 (7) | 0.0441 (10) | −0.0006 (6) | −0.0077 (7) | −0.0044 (7) |
C7 | 0.0266 (7) | 0.0200 (7) | 0.0295 (8) | 0.0028 (6) | 0.0035 (6) | −0.0041 (6) |
C8 | 0.0223 (6) | 0.0221 (7) | 0.0266 (8) | −0.0011 (6) | 0.0025 (6) | −0.0003 (6) |
C9 | 0.0246 (7) | 0.0288 (8) | 0.0267 (8) | 0.0015 (6) | 0.0063 (6) | −0.0011 (6) |
C10 | 0.0284 (8) | 0.0241 (7) | 0.0449 (11) | 0.0006 (6) | −0.0021 (7) | −0.0076 (7) |
C11 | 0.0287 (7) | 0.0280 (7) | 0.0331 (9) | 0.0055 (6) | 0.0031 (6) | −0.0009 (7) |
C12 | 0.0339 (8) | 0.0249 (8) | 0.0278 (9) | 0.0003 (6) | 0.0001 (7) | −0.0046 (6) |
C13 | 0.0287 (8) | 0.0221 (8) | 0.0522 (11) | −0.0038 (6) | 0.0107 (8) | −0.0073 (7) |
C14 | 0.0363 (8) | 0.0314 (8) | 0.0321 (9) | −0.0007 (6) | 0.0069 (7) | −0.0081 (7) |
C15 | 0.0290 (7) | 0.0248 (7) | 0.0239 (8) | −0.0014 (6) | 0.0009 (6) | −0.0004 (6) |
C16 | 0.0289 (7) | 0.0273 (8) | 0.0459 (11) | −0.0001 (7) | 0.0012 (7) | −0.0109 (7) |
C17 | 0.0279 (7) | 0.0304 (8) | 0.0241 (8) | 0.0021 (6) | 0.0024 (6) | −0.0012 (6) |
C18 | 0.0324 (8) | 0.0224 (7) | 0.0306 (9) | 0.0005 (6) | 0.0000 (7) | −0.0033 (7) |
C19 | 0.0354 (8) | 0.0234 (7) | 0.0405 (10) | −0.0006 (6) | 0.0102 (8) | 0.0017 (7) |
C20 | 0.0247 (7) | 0.0241 (7) | 0.0323 (9) | −0.0002 (6) | 0.0033 (7) | −0.0036 (7) |
C21 | 0.0299 (7) | 0.0364 (9) | 0.0302 (9) | 0.0076 (7) | 0.0000 (7) | 0.0005 (7) |
F1—C6 | 1.372 (2) | C8—C17 | 1.523 (2) |
F2—C10 | 1.370 (2) | C8—H1c8 | 0.96 |
O1—C5 | 1.360 (2) | C9—C11 | 1.522 (2) |
O1—H1 | 0.85 (2) | C9—H1c9 | 0.96 |
O2—C12 | 1.368 (2) | C9—H2c9 | 0.96 |
O2—H2 | 0.85 (2) | C10—C13 | 1.371 (3) |
N1—C3 | 1.4818 (18) | C10—C18 | 1.377 (2) |
N1—C15 | 1.468 (2) | C11—C21 | 1.523 (2) |
N1—C20 | 1.4747 (19) | C11—H1c11 | 0.96 |
N2—C4 | 1.4758 (19) | C11—H2c11 | 0.96 |
N2—C8 | 1.4874 (18) | C12—C14 | 1.390 (2) |
N2—C20 | 1.4805 (19) | C13—C19 | 1.381 (2) |
C1—C2 | 1.395 (2) | C13—H1c13 | 0.96 |
C1—C6 | 1.379 (2) | C14—C16 | 1.387 (2) |
C1—H1c1 | 0.96 | C14—H1c14 | 0.96 |
C2—C4 | 1.509 (2) | C15—H1c15 | 0.96 |
C2—C12 | 1.400 (2) | C15—H2c15 | 0.96 |
C3—C8 | 1.526 (2) | C16—H1c16 | 0.96 |
C3—C9 | 1.530 (2) | C17—C21 | 1.526 (2) |
C3—H1c3 | 0.96 | C17—H1c17 | 0.96 |
C4—H1c4 | 0.96 | C17—H2c17 | 0.96 |
C4—H2c4 | 0.96 | C18—H1c18 | 0.96 |
C5—C7 | 1.400 (2) | C19—H1c19 | 0.96 |
C5—C19 | 1.398 (2) | C20—H1c20 | 0.96 |
C6—C16 | 1.373 (3) | C20—H2c20 | 0.96 |
C7—C15 | 1.514 (2) | C21—H1c21 | 0.96 |
C7—C18 | 1.392 (2) | C21—H2c21 | 0.96 |
C5—O1—H1 | 107.6 (15) | C13—C10—C18 | 122.66 (16) |
C12—O2—H2 | 104.7 (16) | C9—C11—C21 | 110.60 (13) |
C3—N1—C15 | 114.79 (12) | C9—C11—H1c11 | 109.47 |
C3—N1—C20 | 103.30 (11) | C9—C11—H2c11 | 109.47 |
C15—N1—C20 | 112.07 (11) | C21—C11—H1c11 | 109.47 |
C4—N2—C8 | 113.02 (11) | C21—C11—H2c11 | 109.47 |
C4—N2—C20 | 111.82 (11) | H1c11—C11—H2c11 | 108.32 |
C8—N2—C20 | 106.20 (11) | O2—C12—C2 | 121.15 (14) |
C2—C1—C6 | 118.79 (16) | O2—C12—C14 | 118.45 (15) |
C2—C1—H1c1 | 120.6 | C2—C12—C14 | 120.40 (15) |
C6—C1—H1c1 | 120.6 | C10—C13—C19 | 118.45 (15) |
C1—C2—C4 | 120.66 (14) | C10—C13—H1c13 | 120.78 |
C1—C2—C12 | 119.20 (14) | C19—C13—H1c13 | 120.78 |
C4—C2—C12 | 120.06 (14) | C12—C14—C16 | 120.23 (16) |
N1—C3—C8 | 100.13 (11) | C12—C14—H1c14 | 119.89 |
N1—C3—C9 | 115.24 (12) | C16—C14—H1c14 | 119.89 |
N1—C3—H1c3 | 113.88 | N1—C15—C7 | 112.94 (13) |
C8—C3—C9 | 114.52 (12) | N1—C15—H1c15 | 109.47 |
C8—C3—H1c3 | 114.61 | N1—C15—H2c15 | 109.47 |
C9—C3—H1c3 | 99.29 | C7—C15—H1c15 | 109.47 |
N2—C4—C2 | 111.48 (12) | C7—C15—H2c15 | 109.47 |
N2—C4—H1c4 | 109.47 | H1c15—C15—H2c15 | 105.76 |
N2—C4—H2c4 | 109.47 | C6—C16—C14 | 118.49 (15) |
C2—C4—H1c4 | 109.47 | C6—C16—H1c16 | 120.75 |
C2—C4—H2c4 | 109.47 | C14—C16—H1c16 | 120.75 |
H1c4—C4—H2c4 | 107.38 | C8—C17—C21 | 111.23 (13) |
O1—C5—C7 | 122.28 (13) | C8—C17—H1c17 | 109.47 |
O1—C5—C19 | 117.78 (15) | C8—C17—H2c17 | 109.47 |
C7—C5—C19 | 119.93 (15) | C21—C17—H1c17 | 109.47 |
F1—C6—C1 | 118.40 (16) | C21—C17—H2c17 | 109.47 |
F1—C6—C16 | 118.73 (14) | H1c17—C17—H2c17 | 107.66 |
C1—C6—C16 | 122.88 (16) | C7—C18—C10 | 119.35 (16) |
C5—C7—C15 | 122.18 (14) | C7—C18—H1c18 | 120.33 |
C5—C7—C18 | 118.99 (14) | C10—C18—H1c18 | 120.32 |
C15—C7—C18 | 118.65 (14) | C5—C19—C13 | 120.61 (16) |
N2—C8—C3 | 103.77 (11) | C5—C19—H1c19 | 119.7 |
N2—C8—C17 | 110.70 (12) | C13—C19—H1c19 | 119.7 |
N2—C8—H1c8 | 113.54 | N1—C20—N2 | 105.82 (11) |
C3—C8—C17 | 112.67 (12) | N1—C20—H1c20 | 109.47 |
C3—C8—H1c8 | 111.6 | N1—C20—H2c20 | 109.47 |
C17—C8—H1c8 | 104.79 | N2—C20—H1c20 | 109.47 |
C3—C9—C11 | 113.83 (13) | N2—C20—H2c20 | 109.47 |
C3—C9—H1c9 | 109.47 | H1c20—C20—H2c20 | 112.89 |
C3—C9—H2c9 | 109.47 | C11—C21—C17 | 109.50 (13) |
C11—C9—H1c9 | 109.47 | C11—C21—H1c21 | 109.47 |
C11—C9—H2c9 | 109.47 | C11—C21—H2c21 | 109.47 |
H1c9—C9—H2c9 | 104.73 | C17—C21—H1c21 | 109.47 |
F2—C10—C13 | 118.53 (14) | C17—C21—H2c21 | 109.47 |
F2—C10—C18 | 118.81 (16) | H1c21—C21—H2c21 | 109.45 |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1···N1 | 0.85 (2) | 1.89 (2) | 2.6540 (17) | 148 (2) |
O2—H2···N2 | 0.85 (2) | 1.89 (2) | 2.6741 (18) | 152 (2) |
O1—H1···C15 | 0.85 (2) | 2.45 (2) | 2.937 (2) | 117.4 (18) |
O2—H2···C4 | 0.85 (2) | 2.35 (2) | 2.867 (2) | 119.3 (19) |
C13—H1C13···F2i | 0.96 | 2.43 | 3.2645 (19) | 145 |
C17—H2C17···F2ii | 0.96 | 2.54 | 3.356 (2) | 142 |
Symmetry codes: (i) −x, −y, z+1/2; (ii) x+1/2, −y+1/2, z+1. |
Experimental details
Crystal data | |
Chemical formula | C21H24F2N2O2 |
Mr | 374.4 |
Crystal system, space group | Orthorhombic, Pna21 |
Temperature (K) | 120 |
a, b, c (Å) | 15.4029 (4), 18.7822 (4), 6.1639 (2) |
V (Å3) | 1783.22 (8) |
Z | 4 |
Radiation type | Cu Kα |
µ (mm−1) | 0.86 |
Crystal size (mm) | 0.31 × 0.15 × 0.11 |
Data collection | |
Diffractometer | Agilent Xcalibur (Atlas, Gemini ultra) diffractometer |
Absorption correction | Multi-scan (CrysAlis PRO; Agilent, 2010) |
Tmin, Tmax | 0.222, 1 |
No. of measured, independent and observed [I > 3σ(I)] reflections | 40310, 3177, 2984 |
Rint | 0.049 |
(sin θ/λ)max (Å−1) | 0.598 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.030, 0.077, 1.42 |
No. of reflections | 3177 |
No. of parameters | 250 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.15, −0.11 |
Computer programs: CrysAlis PRO (Agilent, 2010), SUPERFLIP (Palatinus & Chapuis, 2007), JANA2006 (Petříček et al., 2006), DIAMOND (Brandenburg & Putz, 2005).
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1···N1 | 0.85 (2) | 1.89 (2) | 2.6540 (17) | 148 (2) |
O2—H2···N2 | 0.85 (2) | 1.89 (2) | 2.6741 (18) | 152 (2) |
C13—H1C13···F2i | 0.96 | 2.43 | 3.2645 (19) | 144.88 |
C17—H2C17···F2ii | 0.96 | 2.54 | 3.356 (2) | 142 |
Symmetry codes: (i) −x, −y, z+1/2; (ii) x+1/2, −y+1/2, z+1. |
Acknowledgements
The authors acknowledge the Dirección de Investigaciones, Sede Bogotá (DIB) de la Universidad Nacional de Colombia, for financial support of this work, as well as the Praemium Academiae project of the Academy of Sciences of the Czech Republic. DQ acknowledges the Vicerrectoría Académica de la Universidad Nacional de Colombia for a fellowship.
References
Agilent (2010). CrysAlis PRO. Agilent Technologies, Yarnton, Oxfordshire, England. Google Scholar
Brandenburg, K. & Putz, H. (2005). DIAMOND. Crystal Impact, Bonn, Germany. Google Scholar
Hutchins, R. O., Kopp, L. D. & Eliel, E. L. (1968). J. Am. Chem. Soc. 90, 7174–7175. CrossRef CAS Web of Science Google Scholar
Palatinus, L. & Chapuis, G. (2007). J. Appl. Cryst. 40, 786–790. Web of Science CrossRef CAS IUCr Journals Google Scholar
Petříček, V., Dusěk, M. & Palatinus, L. (2006). JANA2006. Institute of Physics, Prague, Czech Republic. Google Scholar
Rivera, A., Quiroga, D., Ríos-Motta, J., Dušek, M. & Fejfarová, K. (2011). Acta Cryst. E67, o1542. Web of Science CSD CrossRef IUCr Journals Google Scholar
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Typically the 1,1-diamines tend to adopt a conformation in which the arrangement of electron pairs is anti periplanar. This behavior is known as `rabbit-ears' effect (Hutchins et al., 1968), however, this effect can be avoided by restriction of the 1,2-diamine in cyclic molecules. Recently, we reported the synthesis and the crystal structure of rac-4,4'-difluoro-2,2'-{[(3aRS,7aRS)-2,3,3a,4,5,6,7,7a- octahydro- 1H-1,3-benzimidazole-1,3-diyl] bis(methylene)]}diphenol (Rivera et al., 2011), which has trans stereochemistry in the 1,2-diamine moiety with the lone pairs located in anti disposition avoiding the repulsive interactions. Now we reported the synthesis and crystal structure of the meso diastereoisomer with absolute configuration (R,S) where surprisingly the lone pairs of the N atoms are located in syn disposition.
The molecular structure and atom-numbering scheme for (I) are shown in Fig. 1. In the molecular structure of the title compound, the two N atoms of the heterocyclic ring interact with the H atoms of the hydroxy groups by intramolecular hydrogen bonds O—H···N, with N···O interatomic distance values around 2.66 Å, as well as the values of C—O and O—H bond lengths are 1.363 (3) Å and 0.83 (3) Å, respectively. The cyclohexane ring adopts a chair conformation while the heterocyclic ring arranged diagonally respect to the cyclohexane ring with dihedral angle between planes of 25.46 (96)°. The heterocyclic ring adopts an envelope conformation according to the value of the N2—C5—N1—C16 torsion angle of -7.91°. Bond angles around the N atoms N1 and N2 show a higher sp3 character to the N1 and N2 N atoms with pyramidalization involved in the hydrogen bond type interactions [Σ(CNC) N1 = 331.3°, Σ(CNC) N2 = 330.4°]. Moreover, the benzyl groups are located in an unexpected 1,3-diequatorial syn arrangement in the heterocyclic ring with dihedral angle between the planes containing the aromatic rings of 53.80 (30)°. The nonbonding pairs of amino groups involved in the intermolecular hydrogen bonding interactions do not suffer the `rabbit-ear effect' having a syn arrangement demonstrating that the title compound is an exception of this effect.
The stability of the crystal lattice of the title compound is related with non classical intermolecular interactions C—H···F that hold molecules linked in extended chains along the c axis. There are O—H···C and C—H···F weak interactions (table 1), the latter involve halogen group in molecular contact with an electron-deficient C—H bond of the aromatic ring of a second molecule.