Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270103020985/fr1427sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270103020985/fr1427Isup2.hkl | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270103020985/fr1427IIsup3.hkl |
CCDC references: 226127; 226128
Compound (I) was synthesized according to literature data (Nesterov et al., 2000) and recrystallized from acetonitrile [m.p. 503 K]. Compound (II) [m.p. 411 K] was synthesized from the Wittig reaction of 1-(dimethylamino)-4-formyl-naphthalene and (4-nitrocinnamyl)(triphenyl)phosphonium chloride using sodium methoxide in methanol as a base. Crystals of (I) and (II) suitable for X-ray diffraction were grown by slow isothermal evaporation from ethanol solution.
All H atoms were positioned geometrically and treated as riding, with C—H distances of 0.95–0.98 Å. Uiso values for H atoms were assigned as 1.2Ueq(C) (1.5Ueq for methyl H atoms).
For both compounds, data collection: SMART (Bruker, 1998); cell refinement: SMART; data reduction: SAINT (Bruker, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Sheldrick, 1994); software used to prepare material for publication: SHELXTL.
C17H17N3O2 | F(000) = 624 |
Mr = 295.34 | Dx = 1.337 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yn | Cell parameters from 320 reflections |
a = 6.1191 (18) Å | θ = 4–24° |
b = 7.168 (2) Å | µ = 0.09 mm−1 |
c = 33.449 (10) Å | T = 110 K |
β = 91.408 (9)° | Plate, dark red |
V = 1466.7 (7) Å3 | 0.50 × 0.40 × 0.10 mm |
Z = 4 |
Bruker SMART CCD area-detector diffractometer | 1809 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.027 |
Graphite monochromator | θmax = 25.7°, θmin = 2.4° |
ϕ and ω scans | h = −7→6 |
7168 measured reflections | k = −8→8 |
2740 independent reflections | l = −40→32 |
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)] = 0.059 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.145 | H-atom parameters constrained |
S = 1.02 | w = 1/[σ2(Fo2) + (0.08P)2] where P = (Fo2 + 2Fc2)/3 |
2740 reflections | (Δ/σ)max < 0.001 |
201 parameters | Δρmax = 0.49 e Å−3 |
0 restraints | Δρmin = −0.20 e Å−3 |
C17H17N3O2 | V = 1466.7 (7) Å3 |
Mr = 295.34 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 6.1191 (18) Å | µ = 0.09 mm−1 |
b = 7.168 (2) Å | T = 110 K |
c = 33.449 (10) Å | 0.50 × 0.40 × 0.10 mm |
β = 91.408 (9)° |
Bruker SMART CCD area-detector diffractometer | 1809 reflections with I > 2σ(I) |
7168 measured reflections | Rint = 0.027 |
2740 independent reflections |
R[F2 > 2σ(F2)] = 0.059 | 0 restraints |
wR(F2) = 0.145 | H-atom parameters constrained |
S = 1.02 | Δρmax = 0.49 e Å−3 |
2740 reflections | Δρmin = −0.20 e Å−3 |
201 parameters |
Experimental. The compound was characterized by 1H and 13C NMR and GC—MS spectrometry. 1H NMR (CDCl3, 300 MHz) δ 8.38 (d, 1H, J = 8.83 Hz), 8.24 (d, 2H, J = 8.83 Hz), 7.64 (d, 2H, J = 8.82 Hz), 7.27 (d, 2H, J = 9.19 Hz), 7.25 (overlapping m, 1H), 7.08 (d, 1H, J = 15.81 Hz), 6.74 (d, 2H, J = 9.19 Hz), 3.01 (s, 6H) p.p.m.. 13C NMR (CDCl3, 75 MHz) δ 154.9, 150.1, 147.5, 142.5, 139.6, 137.8, 133.4, 127.5, 124.2, 122.7, 112.6, 40.5 p.p.m.. GC—MS: calculated for C17H17N3O2 295.34, found 295.34. |
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 | ||
O1 | 0.9852 (2) | 0.6619 (2) | 0.03712 (4) | 0.0452 (4) | |
O2 | 1.2663 (2) | 0.8130 (2) | 0.06083 (4) | 0.0497 (5) | |
N1 | 0.2472 (2) | 0.7139 (2) | 0.28042 (4) | 0.0287 (4) | |
N2 | −0.0505 (2) | 0.7440 (2) | 0.43912 (4) | 0.0284 (4) | |
N3 | 1.0874 (3) | 0.7372 (2) | 0.06480 (5) | 0.0310 (4) | |
C1 | 0.1806 (3) | 0.7337 (2) | 0.32052 (5) | 0.0249 (4) | |
C2 | 0.3038 (3) | 0.8147 (3) | 0.35208 (6) | 0.0281 (5) | |
H2A | 0.4412 | 0.8698 | 0.3467 | 0.034* | |
C3 | 0.2288 (3) | 0.8155 (3) | 0.39082 (5) | 0.0266 (4) | |
H3A | 0.3168 | 0.8701 | 0.4115 | 0.032* | |
C4 | 0.0250 (3) | 0.7372 (2) | 0.40036 (5) | 0.0244 (4) | |
C5 | −0.0990 (3) | 0.6572 (3) | 0.36844 (5) | 0.0267 (4) | |
H5A | −0.2368 | 0.6022 | 0.3736 | 0.032* | |
C6 | −0.0220 (3) | 0.6580 (3) | 0.32987 (5) | 0.0264 (4) | |
H6A | −0.1101 | 0.6052 | 0.3090 | 0.032* | |
C7 | 0.4461 (3) | 0.7428 (3) | 0.27092 (6) | 0.0284 (5) | |
H7A | 0.5473 | 0.7858 | 0.2909 | 0.034* | |
C8 | 0.5208 (3) | 0.7121 (3) | 0.23098 (6) | 0.0288 (5) | |
H8A | 0.4199 | 0.6670 | 0.2112 | 0.035* | |
C9 | 0.7277 (3) | 0.7450 (3) | 0.22069 (5) | 0.0273 (4) | |
H9A | 0.8269 | 0.7801 | 0.2417 | 0.033* | |
C10 | 0.8170 (3) | 0.7326 (2) | 0.18055 (5) | 0.0242 (4) | |
C11 | 0.7044 (3) | 0.6488 (3) | 0.14781 (5) | 0.0260 (4) | |
H11A | 0.5674 | 0.5903 | 0.1518 | 0.031* | |
C12 | 0.7912 (3) | 0.6508 (3) | 0.10997 (5) | 0.0273 (5) | |
H12A | 0.7150 | 0.5949 | 0.0880 | 0.033* | |
C13 | 0.9922 (3) | 0.7365 (2) | 0.10488 (5) | 0.0240 (4) | |
C14 | 1.1098 (3) | 0.8190 (3) | 0.13617 (6) | 0.0280 (5) | |
H14A | 1.2469 | 0.8768 | 0.1318 | 0.034* | |
C15 | 1.0213 (3) | 0.8145 (3) | 0.17396 (5) | 0.0261 (4) | |
H15A | 1.1008 | 0.8681 | 0.1958 | 0.031* | |
C16 | 0.1044 (3) | 0.7830 (3) | 0.47203 (6) | 0.0364 (5) | |
H16A | 0.1658 | 0.9081 | 0.4687 | 0.055* | |
H16B | 0.2225 | 0.6906 | 0.4720 | 0.055* | |
H16C | 0.0288 | 0.7764 | 0.4975 | 0.055* | |
C17 | −0.2394 (3) | 0.6308 (3) | 0.44919 (6) | 0.0387 (5) | |
H17A | −0.3624 | 0.6615 | 0.4310 | 0.058* | |
H17B | −0.2799 | 0.6566 | 0.4768 | 0.058* | |
H17C | −0.2029 | 0.4984 | 0.4465 | 0.058* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0499 (9) | 0.0543 (11) | 0.0315 (8) | 0.0004 (7) | 0.0024 (7) | −0.0046 (7) |
O2 | 0.0490 (9) | 0.0574 (11) | 0.0435 (10) | −0.0181 (8) | 0.0162 (7) | −0.0042 (8) |
N1 | 0.0310 (9) | 0.0261 (9) | 0.0290 (9) | −0.0008 (6) | 0.0037 (7) | −0.0007 (7) |
N2 | 0.0310 (9) | 0.0275 (10) | 0.0268 (9) | −0.0017 (7) | 0.0040 (7) | −0.0015 (7) |
N3 | 0.0362 (9) | 0.0262 (10) | 0.0309 (10) | 0.0046 (7) | 0.0050 (7) | 0.0004 (7) |
C1 | 0.0260 (10) | 0.0200 (10) | 0.0286 (10) | 0.0041 (7) | 0.0022 (8) | 0.0007 (8) |
C2 | 0.0280 (10) | 0.0226 (10) | 0.0339 (11) | −0.0010 (8) | 0.0034 (8) | 0.0006 (8) |
C3 | 0.0297 (10) | 0.0203 (10) | 0.0298 (11) | −0.0009 (8) | −0.0010 (8) | −0.0019 (8) |
C4 | 0.0275 (10) | 0.0172 (10) | 0.0285 (11) | 0.0051 (7) | 0.0028 (8) | 0.0007 (8) |
C5 | 0.0254 (9) | 0.0213 (10) | 0.0334 (11) | 0.0002 (7) | 0.0019 (8) | 0.0021 (8) |
C6 | 0.0267 (10) | 0.0199 (10) | 0.0326 (11) | −0.0004 (7) | −0.0016 (8) | 0.0007 (8) |
C7 | 0.0298 (10) | 0.0259 (11) | 0.0293 (11) | 0.0003 (8) | −0.0002 (8) | 0.0020 (8) |
C8 | 0.0301 (10) | 0.0285 (11) | 0.0278 (11) | 0.0008 (8) | 0.0003 (8) | 0.0034 (8) |
C9 | 0.0305 (10) | 0.0223 (10) | 0.0290 (11) | −0.0013 (7) | −0.0005 (8) | −0.0003 (8) |
C10 | 0.0253 (9) | 0.0185 (10) | 0.0290 (10) | 0.0042 (7) | 0.0016 (8) | 0.0026 (8) |
C11 | 0.0249 (9) | 0.0217 (10) | 0.0315 (11) | −0.0007 (7) | 0.0034 (8) | 0.0023 (8) |
C12 | 0.0298 (10) | 0.0214 (10) | 0.0307 (11) | 0.0018 (8) | −0.0011 (8) | −0.0015 (8) |
C13 | 0.0285 (10) | 0.0199 (10) | 0.0237 (10) | 0.0053 (7) | 0.0041 (8) | 0.0026 (8) |
C14 | 0.0285 (10) | 0.0205 (10) | 0.0352 (11) | 0.0008 (8) | 0.0031 (8) | 0.0003 (8) |
C15 | 0.0281 (10) | 0.0214 (10) | 0.0289 (10) | −0.0002 (8) | −0.0007 (8) | −0.0022 (8) |
C16 | 0.0428 (12) | 0.0389 (13) | 0.0277 (11) | −0.0071 (9) | 0.0045 (9) | −0.0028 (9) |
C17 | 0.0393 (12) | 0.0436 (14) | 0.0336 (12) | −0.0079 (10) | 0.0076 (9) | −0.0031 (10) |
O1—N3 | 1.230 (2) | C8—C9 | 1.341 (2) |
O2—N3 | 1.232 (2) | C8—H8A | 0.9500 |
N1—C7 | 1.283 (2) | C9—C10 | 1.464 (3) |
N1—C1 | 1.418 (2) | C9—H9A | 0.9500 |
N2—C4 | 1.388 (2) | C10—C15 | 1.404 (2) |
N2—C17 | 1.458 (2) | C10—C11 | 1.413 (2) |
N2—C16 | 1.462 (2) | C11—C12 | 1.385 (3) |
N3—C13 | 1.474 (2) | C11—H11A | 0.9500 |
C1—C6 | 1.396 (2) | C12—C13 | 1.389 (3) |
C1—C2 | 1.407 (3) | C12—H12A | 0.9500 |
C2—C3 | 1.385 (3) | C13—C14 | 1.387 (3) |
C2—H2A | 0.9500 | C14—C15 | 1.388 (3) |
C3—C4 | 1.411 (3) | C14—H14A | 0.9500 |
C3—H3A | 0.9500 | C15—H15A | 0.9500 |
C4—C5 | 1.416 (3) | C16—H16A | 0.9800 |
C5—C6 | 1.384 (3) | C16—H16B | 0.9800 |
C5—H5A | 0.9500 | C16—H16C | 0.9800 |
C6—H6A | 0.9500 | C17—H17A | 0.9800 |
C7—C8 | 1.439 (3) | C17—H17B | 0.9800 |
C7—H7A | 0.9500 | C17—H17C | 0.9800 |
C7—N1—C1 | 120.96 (16) | C8—C9—H9A | 116.6 |
C4—N2—C17 | 118.71 (15) | C10—C9—H9A | 116.6 |
C4—N2—C16 | 119.04 (16) | C15—C10—C11 | 118.36 (16) |
C17—N2—C16 | 115.83 (15) | C15—C10—C9 | 118.18 (16) |
O1—N3—O2 | 123.32 (16) | C11—C10—C9 | 123.41 (16) |
O1—N3—C13 | 118.56 (16) | C12—C11—C10 | 120.89 (17) |
O2—N3—C13 | 118.12 (16) | C12—C11—H11A | 119.6 |
C6—C1—C2 | 117.03 (17) | C10—C11—H11A | 119.6 |
C6—C1—N1 | 116.76 (16) | C11—C12—C13 | 118.51 (17) |
C2—C1—N1 | 126.15 (16) | C11—C12—H12A | 120.7 |
C3—C2—C1 | 121.32 (17) | C13—C12—H12A | 120.7 |
C3—C2—H2A | 119.3 | C14—C13—C12 | 122.69 (17) |
C1—C2—H2A | 119.3 | C14—C13—N3 | 118.38 (16) |
C2—C3—C4 | 121.66 (17) | C12—C13—N3 | 118.93 (16) |
C2—C3—H3A | 119.2 | C13—C14—C15 | 118.08 (17) |
C4—C3—H3A | 119.2 | C13—C14—H14A | 121.0 |
N2—C4—C3 | 120.91 (17) | C15—C14—H14A | 121.0 |
N2—C4—C5 | 122.26 (16) | C14—C15—C10 | 121.45 (17) |
C3—C4—C5 | 116.80 (16) | C14—C15—H15A | 119.3 |
C6—C5—C4 | 120.81 (17) | C10—C15—H15A | 119.3 |
C6—C5—H5A | 119.6 | N2—C16—H16A | 109.5 |
C4—C5—H5A | 119.6 | N2—C16—H16B | 109.5 |
C5—C6—C1 | 122.37 (17) | H16A—C16—H16B | 109.5 |
C5—C6—H6A | 118.8 | N2—C16—H16C | 109.5 |
C1—C6—H6A | 118.8 | H16A—C16—H16C | 109.5 |
N1—C7—C8 | 122.00 (18) | H16B—C16—H16C | 109.5 |
N1—C7—H7A | 119.0 | N2—C17—H17A | 109.5 |
C8—C7—H7A | 119.0 | N2—C17—H17B | 109.5 |
C9—C8—C7 | 122.30 (18) | H17A—C17—H17B | 109.5 |
C9—C8—H8A | 118.8 | N2—C17—H17C | 109.5 |
C7—C8—H8A | 118.8 | H17A—C17—H17C | 109.5 |
C8—C9—C10 | 126.89 (18) | H17B—C17—H17C | 109.5 |
C7—N1—C1—C6 | −165.24 (17) | C7—C8—C9—C10 | −174.95 (18) |
C7—N1—C1—C2 | 11.6 (3) | C8—C9—C10—C15 | 164.89 (18) |
C6—C1—C2—C3 | 1.3 (3) | C8—C9—C10—C11 | −12.6 (3) |
N1—C1—C2—C3 | −175.53 (17) | C15—C10—C11—C12 | −1.3 (3) |
C1—C2—C3—C4 | −0.7 (3) | C9—C10—C11—C12 | 176.14 (17) |
C17—N2—C4—C3 | −168.17 (17) | C10—C11—C12—C13 | 0.3 (3) |
C16—N2—C4—C3 | −17.4 (3) | C11—C12—C13—C14 | 0.4 (3) |
C17—N2—C4—C5 | 13.6 (3) | C11—C12—C13—N3 | 179.21 (16) |
C16—N2—C4—C5 | 164.29 (17) | O1—N3—C13—C14 | 178.96 (16) |
C2—C3—C4—N2 | −178.14 (17) | O2—N3—C13—C14 | −0.8 (2) |
C2—C3—C4—C5 | 0.2 (3) | O1—N3—C13—C12 | 0.1 (2) |
N2—C4—C5—C6 | 177.92 (16) | O2—N3—C13—C12 | −179.67 (17) |
C3—C4—C5—C6 | −0.4 (3) | C12—C13—C14—C15 | 0.1 (3) |
C4—C5—C6—C1 | 1.1 (3) | N3—C13—C14—C15 | −178.73 (16) |
C2—C1—C6—C5 | −1.5 (3) | C13—C14—C15—C10 | −1.2 (3) |
N1—C1—C6—C5 | 175.61 (16) | C11—C10—C15—C14 | 1.8 (3) |
C1—N1—C7—C8 | 175.97 (17) | C9—C10—C15—C14 | −175.76 (16) |
N1—C7—C8—C9 | 178.88 (18) |
C22H20N2O2 | Z = 2 |
Mr = 344.40 | F(000) = 364 |
Triclinic, P1 | Dx = 1.306 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 6.7383 (10) Å | Cell parameters from 320 reflections |
b = 10.3948 (16) Å | θ = 4–24° |
c = 12.8735 (19) Å | µ = 0.08 mm−1 |
α = 79.933 (8)° | T = 110 K |
β = 81.754 (8)° | Prism, red |
γ = 84.103 (8)° | 0.45 × 0.35 × 0.25 mm |
V = 875.9 (2) Å3 |
Bruker SMART CCD area-detector diffractometer | 2589 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.024 |
Graphite monochromator | θmax = 27.0°, θmin = 2.0° |
ϕ and ω scans | h = −8→8 |
6053 measured reflections | k = −13→12 |
3800 independent reflections | l = −16→12 |
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)] = 0.069 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.187 | H-atom parameters constrained |
S = 1.03 | w = 1/[σ2(Fo2) + (0.1177P)2] where P = (Fo2 + 2Fc2)/3 |
3800 reflections | (Δ/σ)max < 0.001 |
237 parameters | Δρmax = 0.53 e Å−3 |
0 restraints | Δρmin = −0.27 e Å−3 |
C22H20N2O2 | γ = 84.103 (8)° |
Mr = 344.40 | V = 875.9 (2) Å3 |
Triclinic, P1 | Z = 2 |
a = 6.7383 (10) Å | Mo Kα radiation |
b = 10.3948 (16) Å | µ = 0.08 mm−1 |
c = 12.8735 (19) Å | T = 110 K |
α = 79.933 (8)° | 0.45 × 0.35 × 0.25 mm |
β = 81.754 (8)° |
Bruker SMART CCD area-detector diffractometer | 2589 reflections with I > 2σ(I) |
6053 measured reflections | Rint = 0.024 |
3800 independent reflections |
R[F2 > 2σ(F2)] = 0.069 | 0 restraints |
wR(F2) = 0.187 | H-atom parameters constrained |
S = 1.03 | Δρmax = 0.53 e Å−3 |
3800 reflections | Δρmin = −0.27 e Å−3 |
237 parameters |
Experimental. The compound was characterized by 1H NMR (CDCl3, 250 MHz) δ 8.27 (m, 1H), 8.21 (d, 2H, J = 7.5 Hz), 8.18 (m, 1H), 7.69 (d, 1H, J = 8.0 Hz), 7.57 (d, 2H, J = 7.5 Hz), 7.55 (overlapping m, 3H), 7.26 (dd, 1H, J = 15.5, 10.8 Hz), 7.08 (d, 1H, J = 8.0 Hz), 6.99 (dd, 1H, J = 15.0, 10.8 Hz), 6.72 (d, 1H, J = 15.5 Hz), 2.93 (s, 6H) p.p.m.; and high resolution FAB mass spectrometry [calculated for C22H20N2O2 344.1525, found 344.1527]. |
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. All H atoms were placed in geometrically calculated positions and refined using a riding model with C—H distances of 0.95 Å for aromatic H atoms and 0.98 Å for CH3 groups. |
x | y | z | Uiso*/Ueq | ||
O1 | −1.0384 (2) | 0.67282 (14) | −0.04024 (12) | 0.0411 (4) | |
O2 | −1.0984 (2) | 0.85891 (14) | 0.01712 (11) | 0.0364 (4) | |
N1 | 0.7908 (2) | 0.16723 (15) | 0.49113 (12) | 0.0261 (4) | |
N2 | −0.9982 (2) | 0.75348 (16) | 0.01141 (12) | 0.0288 (4) | |
C1 | 0.2790 (3) | 0.33263 (17) | 0.34026 (15) | 0.0252 (4) | |
C2 | 0.3249 (3) | 0.37768 (18) | 0.42734 (15) | 0.0269 (4) | |
H2A | 0.2380 | 0.4449 | 0.4551 | 0.032* | |
C3 | 0.4965 (3) | 0.32774 (18) | 0.47693 (15) | 0.0268 (4) | |
H3A | 0.5227 | 0.3613 | 0.5372 | 0.032* | |
C4 | 0.6256 (3) | 0.23116 (18) | 0.43893 (14) | 0.0242 (4) | |
C5 | 0.5962 (3) | 0.18934 (17) | 0.34257 (14) | 0.0236 (4) | |
C6 | 0.7396 (3) | 0.10256 (18) | 0.29210 (15) | 0.0270 (4) | |
H6A | 0.8578 | 0.0699 | 0.3236 | 0.032* | |
C7 | 0.7109 (3) | 0.06526 (19) | 0.19927 (15) | 0.0311 (5) | |
H7A | 0.8088 | 0.0072 | 0.1667 | 0.037* | |
C8 | 0.5366 (3) | 0.11261 (19) | 0.15176 (15) | 0.0299 (4) | |
H8A | 0.5160 | 0.0854 | 0.0877 | 0.036* | |
C9 | 0.3967 (3) | 0.19763 (18) | 0.19750 (15) | 0.0284 (4) | |
H9A | 0.2804 | 0.2295 | 0.1641 | 0.034* | |
C10 | 0.4215 (3) | 0.23920 (17) | 0.29347 (14) | 0.0241 (4) | |
C11 | 0.0900 (3) | 0.37378 (18) | 0.29624 (15) | 0.0272 (4) | |
H11A | 0.0367 | 0.3104 | 0.2654 | 0.033* | |
C12 | −0.0174 (3) | 0.48997 (18) | 0.29400 (14) | 0.0277 (4) | |
H12A | 0.0274 | 0.5557 | 0.3259 | 0.033* | |
C13 | −0.1990 (3) | 0.51763 (18) | 0.24444 (14) | 0.0268 (4) | |
H13A | −0.2476 | 0.4467 | 0.2207 | 0.032* | |
C14 | −0.3058 (3) | 0.63355 (18) | 0.22864 (14) | 0.0270 (4) | |
H14A | −0.2620 | 0.7035 | 0.2559 | 0.032* | |
C15 | −0.4843 (3) | 0.66225 (17) | 0.17299 (14) | 0.0239 (4) | |
C16 | −0.5573 (3) | 0.56818 (18) | 0.12539 (14) | 0.0259 (4) | |
H16A | −0.4902 | 0.4828 | 0.1293 | 0.031* | |
C17 | −0.7258 (3) | 0.59793 (18) | 0.07281 (14) | 0.0257 (4) | |
H17A | −0.7743 | 0.5340 | 0.0404 | 0.031* | |
C18 | −0.8219 (3) | 0.72228 (17) | 0.06835 (14) | 0.0243 (4) | |
C19 | −0.7555 (3) | 0.81793 (18) | 0.11390 (14) | 0.0272 (4) | |
H19A | −0.8242 | 0.9028 | 0.1099 | 0.033* | |
C20 | −0.5856 (3) | 0.78694 (18) | 0.16573 (14) | 0.0267 (4) | |
H20A | −0.5373 | 0.8520 | 0.1969 | 0.032* | |
C21 | 0.8687 (3) | 0.24241 (19) | 0.55964 (15) | 0.0315 (5) | |
H21A | 0.8962 | 0.3296 | 0.5201 | 0.047* | |
H21B | 0.9934 | 0.1970 | 0.5830 | 0.047* | |
H21C | 0.7691 | 0.2512 | 0.6219 | 0.047* | |
C22 | 0.7447 (3) | 0.03589 (18) | 0.54869 (16) | 0.0311 (5) | |
H22A | 0.6920 | −0.0126 | 0.5012 | 0.047* | |
H22B | 0.6439 | 0.0447 | 0.6105 | 0.047* | |
H22C | 0.8676 | −0.0117 | 0.5726 | 0.047* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0477 (9) | 0.0390 (9) | 0.0419 (9) | 0.0001 (7) | −0.0222 (7) | −0.0101 (7) |
O2 | 0.0354 (8) | 0.0324 (8) | 0.0408 (9) | 0.0058 (6) | −0.0111 (6) | −0.0041 (6) |
N1 | 0.0253 (8) | 0.0265 (8) | 0.0261 (8) | −0.0041 (6) | −0.0072 (6) | 0.0008 (6) |
N2 | 0.0303 (9) | 0.0296 (9) | 0.0256 (9) | −0.0009 (7) | −0.0069 (6) | 0.0001 (7) |
C1 | 0.0252 (9) | 0.0200 (9) | 0.0283 (10) | −0.0039 (7) | −0.0044 (7) | 0.0036 (7) |
C2 | 0.0282 (10) | 0.0227 (10) | 0.0291 (10) | −0.0017 (7) | −0.0039 (7) | −0.0023 (7) |
C3 | 0.0298 (10) | 0.0263 (10) | 0.0250 (10) | −0.0046 (8) | −0.0057 (7) | −0.0032 (7) |
C4 | 0.0226 (9) | 0.0248 (9) | 0.0248 (9) | −0.0057 (7) | −0.0061 (7) | 0.0021 (7) |
C5 | 0.0267 (9) | 0.0210 (9) | 0.0221 (9) | −0.0069 (7) | −0.0034 (7) | 0.0023 (7) |
C6 | 0.0259 (9) | 0.0271 (10) | 0.0274 (10) | −0.0029 (7) | −0.0052 (7) | −0.0007 (7) |
C7 | 0.0330 (10) | 0.0291 (10) | 0.0299 (11) | −0.0019 (8) | 0.0001 (8) | −0.0051 (8) |
C8 | 0.0375 (11) | 0.0325 (11) | 0.0201 (9) | −0.0090 (8) | −0.0041 (8) | −0.0018 (8) |
C9 | 0.0320 (10) | 0.0268 (10) | 0.0259 (10) | −0.0055 (8) | −0.0083 (8) | 0.0022 (7) |
C10 | 0.0257 (9) | 0.0218 (9) | 0.0240 (9) | −0.0062 (7) | −0.0048 (7) | 0.0026 (7) |
C11 | 0.0265 (9) | 0.0264 (10) | 0.0282 (10) | −0.0044 (7) | −0.0072 (7) | 0.0008 (7) |
C12 | 0.0278 (10) | 0.0283 (10) | 0.0258 (10) | −0.0037 (8) | −0.0035 (7) | −0.0001 (7) |
C13 | 0.0265 (9) | 0.0282 (10) | 0.0247 (10) | −0.0055 (7) | −0.0033 (7) | 0.0000 (7) |
C14 | 0.0288 (10) | 0.0278 (10) | 0.0238 (10) | −0.0034 (8) | −0.0052 (7) | −0.0006 (7) |
C15 | 0.0250 (9) | 0.0248 (9) | 0.0196 (9) | −0.0031 (7) | −0.0014 (7) | 0.0023 (7) |
C16 | 0.0271 (9) | 0.0230 (9) | 0.0257 (10) | −0.0008 (7) | −0.0025 (7) | −0.0002 (7) |
C17 | 0.0292 (10) | 0.0251 (10) | 0.0225 (9) | −0.0036 (7) | −0.0029 (7) | −0.0027 (7) |
C18 | 0.0237 (9) | 0.0265 (10) | 0.0213 (9) | −0.0010 (7) | −0.0050 (7) | 0.0009 (7) |
C19 | 0.0298 (10) | 0.0231 (9) | 0.0267 (10) | 0.0023 (7) | −0.0031 (7) | −0.0011 (7) |
C20 | 0.0297 (10) | 0.0264 (10) | 0.0248 (10) | −0.0040 (8) | −0.0053 (7) | −0.0039 (7) |
C21 | 0.0289 (10) | 0.0377 (11) | 0.0288 (10) | −0.0042 (8) | −0.0073 (8) | −0.0039 (8) |
C22 | 0.0305 (10) | 0.0283 (10) | 0.0328 (11) | −0.0029 (8) | −0.0075 (8) | 0.0027 (8) |
O1—N2 | 1.230 (2) | C11—C12 | 1.341 (3) |
O2—N2 | 1.235 (2) | C11—H11A | 0.9500 |
N1—C4 | 1.428 (2) | C12—C13 | 1.440 (2) |
N1—C21 | 1.457 (2) | C12—H12A | 0.9500 |
N1—C22 | 1.475 (2) | C13—C14 | 1.338 (3) |
N2—C18 | 1.463 (2) | C13—H13A | 0.9500 |
C1—C2 | 1.373 (3) | C14—C15 | 1.465 (2) |
C1—C10 | 1.441 (3) | C14—H14A | 0.9500 |
C1—C11 | 1.461 (2) | C15—C20 | 1.396 (3) |
C2—C3 | 1.409 (2) | C15—C16 | 1.403 (3) |
C2—H2A | 0.9500 | C16—C17 | 1.385 (2) |
C3—C4 | 1.369 (3) | C16—H16A | 0.9500 |
C3—H3A | 0.9500 | C17—C18 | 1.381 (2) |
C4—C5 | 1.430 (3) | C17—H17A | 0.9500 |
C5—C6 | 1.419 (3) | C18—C19 | 1.380 (3) |
C5—C10 | 1.424 (2) | C19—C20 | 1.388 (2) |
C6—C7 | 1.364 (3) | C19—H19A | 0.9500 |
C6—H6A | 0.9500 | C20—H20A | 0.9500 |
C7—C8 | 1.407 (3) | C21—H21A | 0.9800 |
C7—H7A | 0.9500 | C21—H21B | 0.9800 |
C8—C9 | 1.366 (3) | C21—H21C | 0.9800 |
C8—H8A | 0.9500 | C22—H22A | 0.9800 |
C9—C10 | 1.415 (3) | C22—H22B | 0.9800 |
C9—H9A | 0.9500 | C22—H22C | 0.9800 |
C4—N1—C21 | 115.40 (15) | C11—C12—C13 | 121.65 (18) |
C4—N1—C22 | 111.35 (14) | C11—C12—H12A | 119.2 |
C21—N1—C22 | 110.93 (14) | C13—C12—H12A | 119.2 |
O1—N2—O2 | 123.32 (15) | C14—C13—C12 | 126.32 (18) |
O1—N2—C18 | 117.90 (16) | C14—C13—H13A | 116.8 |
O2—N2—C18 | 118.78 (16) | C12—C13—H13A | 116.8 |
C2—C1—C10 | 118.02 (16) | C13—C14—C15 | 125.83 (18) |
C2—C1—C11 | 122.21 (17) | C13—C14—H14A | 117.1 |
C10—C1—C11 | 119.74 (17) | C15—C14—H14A | 117.1 |
C1—C2—C3 | 122.33 (18) | C20—C15—C16 | 118.26 (16) |
C1—C2—H2A | 118.8 | C20—C15—C14 | 119.67 (17) |
C3—C2—H2A | 118.8 | C16—C15—C14 | 122.07 (17) |
C4—C3—C2 | 120.53 (17) | C17—C16—C15 | 120.96 (17) |
C4—C3—H3A | 119.7 | C17—C16—H16A | 119.5 |
C2—C3—H3A | 119.7 | C15—C16—H16A | 119.5 |
C3—C4—N1 | 123.45 (17) | C18—C17—C16 | 118.74 (17) |
C3—C4—C5 | 119.59 (16) | C18—C17—H17A | 120.6 |
N1—C4—C5 | 116.96 (16) | C16—C17—H17A | 120.6 |
C6—C5—C10 | 118.70 (17) | C17—C18—C19 | 122.33 (16) |
C6—C5—C4 | 121.94 (16) | C17—C18—N2 | 118.40 (17) |
C10—C5—C4 | 119.32 (17) | C19—C18—N2 | 119.26 (16) |
C7—C6—C5 | 121.23 (17) | C18—C19—C20 | 118.29 (17) |
C7—C6—H6A | 119.4 | C18—C19—H19A | 120.9 |
C5—C6—H6A | 119.4 | C20—C19—H19A | 120.9 |
C6—C7—C8 | 120.09 (18) | C19—C20—C15 | 121.43 (17) |
C6—C7—H7A | 120.0 | C19—C20—H20A | 119.3 |
C8—C7—H7A | 120.0 | C15—C20—H20A | 119.3 |
C9—C8—C7 | 120.20 (18) | N1—C21—H21A | 109.5 |
C9—C8—H8A | 119.9 | N1—C21—H21B | 109.5 |
C7—C8—H8A | 119.9 | H21A—C21—H21B | 109.5 |
C8—C9—C10 | 121.43 (17) | N1—C21—H21C | 109.5 |
C8—C9—H9A | 119.3 | H21A—C21—H21C | 109.5 |
C10—C9—H9A | 119.3 | H21B—C21—H21C | 109.5 |
C9—C10—C5 | 118.33 (17) | N1—C22—H22A | 109.5 |
C9—C10—C1 | 121.91 (16) | N1—C22—H22B | 109.5 |
C5—C10—C1 | 119.73 (17) | H22A—C22—H22B | 109.5 |
C12—C11—C1 | 128.03 (18) | N1—C22—H22C | 109.5 |
C12—C11—H11A | 116.0 | H22A—C22—H22C | 109.5 |
C1—C11—H11A | 116.0 | H22B—C22—H22C | 109.5 |
C10—C1—C2—C3 | −5.4 (3) | C11—C1—C10—C9 | 8.1 (2) |
C11—C1—C2—C3 | 172.99 (16) | C2—C1—C10—C5 | 4.6 (2) |
C1—C2—C3—C4 | 0.2 (3) | C11—C1—C10—C5 | −173.84 (15) |
C2—C3—C4—N1 | −173.65 (15) | C2—C1—C11—C12 | 32.6 (3) |
C2—C3—C4—C5 | 5.8 (3) | C10—C1—C11—C12 | −149.04 (19) |
C21—N1—C4—C3 | −25.0 (2) | C1—C11—C12—C13 | 177.99 (17) |
C22—N1—C4—C3 | 102.6 (2) | C11—C12—C13—C14 | −172.96 (18) |
C21—N1—C4—C5 | 155.59 (16) | C12—C13—C14—C15 | 176.48 (17) |
C22—N1—C4—C5 | −76.8 (2) | C13—C14—C15—C20 | 177.65 (18) |
C3—C4—C5—C6 | 171.52 (16) | C13—C14—C15—C16 | −2.8 (3) |
N1—C4—C5—C6 | −9.0 (2) | C20—C15—C16—C17 | −0.2 (3) |
C3—C4—C5—C10 | −6.4 (2) | C14—C15—C16—C17 | −179.69 (16) |
N1—C4—C5—C10 | 173.10 (14) | C15—C16—C17—C18 | −0.3 (3) |
C10—C5—C6—C7 | −1.0 (3) | C16—C17—C18—C19 | 0.4 (3) |
C4—C5—C6—C7 | −178.92 (17) | C16—C17—C18—N2 | 179.18 (15) |
C5—C6—C7—C8 | −0.1 (3) | O1—N2—C18—C17 | −8.3 (2) |
C6—C7—C8—C9 | 1.0 (3) | O2—N2—C18—C17 | 171.90 (16) |
C7—C8—C9—C10 | −0.7 (3) | O1—N2—C18—C19 | 170.53 (16) |
C8—C9—C10—C5 | −0.5 (3) | O2—N2—C18—C19 | −9.2 (2) |
C8—C9—C10—C1 | 177.58 (16) | C17—C18—C19—C20 | 0.1 (3) |
C6—C5—C10—C9 | 1.3 (2) | N2—C18—C19—C20 | −178.74 (15) |
C4—C5—C10—C9 | 179.26 (15) | C18—C19—C20—C15 | −0.6 (3) |
C6—C5—C10—C1 | −176.81 (15) | C16—C15—C20—C19 | 0.6 (3) |
C4—C5—C10—C1 | 1.1 (2) | C14—C15—C20—C19 | −179.86 (16) |
C2—C1—C10—C9 | −173.42 (16) |
D—H···A | D—H | H···A | D···A | D—H···A |
C9—H9A···O1i | 0.95 | 2.46 | 3.395 (3) | 166 |
Symmetry code: (i) −x−1, −y+1, −z. |
Experimental details
(I) | (II) | |
Crystal data | ||
Chemical formula | C17H17N3O2 | C22H20N2O2 |
Mr | 295.34 | 344.40 |
Crystal system, space group | Monoclinic, P21/n | Triclinic, P1 |
Temperature (K) | 110 | 110 |
a, b, c (Å) | 6.1191 (18), 7.168 (2), 33.449 (10) | 6.7383 (10), 10.3948 (16), 12.8735 (19) |
α, β, γ (°) | 90, 91.408 (9), 90 | 79.933 (8), 81.754 (8), 84.103 (8) |
V (Å3) | 1466.7 (7) | 875.9 (2) |
Z | 4 | 2 |
Radiation type | Mo Kα | Mo Kα |
µ (mm−1) | 0.09 | 0.08 |
Crystal size (mm) | 0.50 × 0.40 × 0.10 | 0.45 × 0.35 × 0.25 |
Data collection | ||
Diffractometer | Bruker SMART CCD area-detector diffractometer | Bruker SMART CCD area-detector diffractometer |
Absorption correction | – | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 7168, 2740, 1809 | 6053, 3800, 2589 |
Rint | 0.027 | 0.024 |
(sin θ/λ)max (Å−1) | 0.610 | 0.639 |
Refinement | ||
R[F2 > 2σ(F2)], wR(F2), S | 0.059, 0.145, 1.02 | 0.069, 0.187, 1.03 |
No. of reflections | 2740 | 3800 |
No. of parameters | 201 | 237 |
H-atom treatment | H-atom parameters constrained | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.49, −0.20 | 0.53, −0.27 |
Computer programs: SMART (Bruker, 1998), SMART, SAINT (Bruker, 1998), SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), SHELXTL (Sheldrick, 1994), SHELXTL.
N1—C7 | 1.283 (2) | C3—C4 | 1.411 (3) |
N1—C1 | 1.418 (2) | C4—C5 | 1.416 (3) |
N2—C4 | 1.388 (2) | C5—C6 | 1.384 (3) |
C1—C6 | 1.396 (2) | C7—C8 | 1.439 (3) |
C1—C2 | 1.407 (3) | C8—C9 | 1.341 (2) |
C2—C3 | 1.385 (3) | C9—C10 | 1.464 (3) |
C7—N1—C1 | 120.96 (16) | N1—C7—C8 | 122.00 (18) |
C4—N2—C17 | 118.71 (15) | C9—C8—C7 | 122.30 (18) |
C4—N2—C16 | 119.04 (16) | C8—C9—C10 | 126.89 (18) |
C17—N2—C16 | 115.83 (15) | ||
C7—N1—C1—C2 | 11.6 (3) | N1—C7—C8—C9 | 178.88 (18) |
C17—N2—C4—C3 | −168.17 (17) | C7—C8—C9—C10 | −174.95 (18) |
C16—N2—C4—C3 | −17.4 (3) | C8—C9—C10—C11 | −12.6 (3) |
C1—N1—C7—C8 | 175.97 (17) |
N1—C4 | 1.428 (2) | C12—C13 | 1.440 (2) |
C1—C11 | 1.461 (2) | C13—C14 | 1.338 (3) |
C11—C12 | 1.341 (3) | C14—C15 | 1.465 (2) |
C4—N1—C21 | 115.40 (15) | C11—C12—C13 | 121.65 (18) |
C4—N1—C22 | 111.35 (14) | C14—C13—C12 | 126.32 (18) |
C21—N1—C22 | 110.93 (14) | C13—C14—C15 | 125.83 (18) |
C12—C11—C1 | 128.03 (18) | ||
C21—N1—C4—C3 | −25.0 (2) | C11—C12—C13—C14 | −172.96 (18) |
C22—N1—C4—C3 | 102.6 (2) | C12—C13—C14—C15 | 176.48 (17) |
C2—C1—C11—C12 | 32.6 (3) | C13—C14—C15—C16 | −2.8 (3) |
C1—C11—C12—C13 | 177.99 (17) |
D—H···A | D—H | H···A | D···A | D—H···A |
C9—H9A···O1i | 0.95 | 2.46 | 3.395 (3) | 166 |
Symmetry code: (i) −x−1, −y+1, −z. |
Molecule I | |||
Torsion angle, ° | |||
C2—C1—N1—C7 | C8—C9—C10—C11 | Energy, kcal/mol | |
X-ray data | 11.6 | -12.6 | |
MM3 best conformation | 29.1 | -14.7 | 18.06 |
MM3 conformation (X-ray like) | 12.3 | -13.8 | 19.24 |
Data range from MM3 | 1.43–29.1 | -14.7–10.1 | 18.06–19.32 |
Molecule II | |||
C2—C1—C11—C12 | C13—C14—C15—C16 | Energy, kcal/mol | |
X-ray data | 32.6 | -2.8 | |
MM3 best conformation | -35.4 | -10.3 | 24.05 |
MM3 conformation (X-ray like) | 34.5 | -2.1 | 24.36 |
Data range from MM3 | -38.4–34.5 | -12.5–7.2 | 24.05–24.70 |
The present investigation is a continuation of a project that includes the syntheses and structural studies of polar conjugated organic molecules (Antipin et al., 1997, 1998; Nesterov et al., 2000). These compounds have applications in non-linear optical, electrooptical, photorefractive, and optical limiting materials (Zyss et al., 1994; Kuzyk & Dirk, 1998).
Synthesis and X-ray structural investigations have been carried out for the title compounds, (I) and (II) (Figs. 1 and 2). Most of the geometric parameters in molecules (I) and (II) are very similar to the standard values (Allen et al., 1987) and very close to literature data for similar polyene derivatives (Childs et al., 1989; Ercan et al., 1996; Nesterov et al., 2000). The title compounds have a trans,trans geometry about conjugated linkages. The molecular skeleton of (I) is slightly non-planar; the dihedral angles between the conjugated linkage and the p-dimethylaminophenyl ring, and between the linkage and the p-nitrophenyl ring, are 13.0 (2) and 13.8 (2)°, respectively. Moreover, the dihedral angle between the slightly pyramidal dimethylamine substituent [the sum of the bond angles around the N atom is 353.5 (1)°] and the phenyl ring is 23.3 (1)°. The length of the C4—N2 bond is 1.388 (2) Å; although this bond is slightly longer than the average conjugated C—N single bond (1.370 Å), it is significantly shorter than the average non-conjugated C—N single bond (1.430 Å) found in the Cambridge Structural Database (CSD; Allen, 2002). As a result of the strong conjugation between donor and acceptor parts of the molecule in (I), substituted phenyl rings in this molecule have a noticeable quinoid structure, which is most? pronounced in the dimethylaniline phenyl ring (Table 1). The nitro group is essentially coplanar with the aromatic ring; the dihedral angle between planes of these fragments is 1.0 (2)°.
The molecular skeleton of (II) is not planar; the dihedral angles between the conjugated linkage and the naphthalene ring, and between the linkage and the substituted phenyl ring, are 36.1 (2) and 2.7 (3)°, respectively. The dimethylamine substituent in this molecule is more pyramidal [the sum of the bond angles around the N atom is 337.6 (2)°] than that in (I). Furthermore, the dihedral angle between this substituent and the naphthalene ring is 71.7 (1)°, and the C4—N1 bond is much longer than the corresponding C4—N2 bond in (I); its length [1.428 (2) Å] agrees with the standard bond length of the non-conjugated C—N single bond (Allen et al., 1987). These torsion angles and bond lengths indicate that there is considerably less effective? donor–acceptor interaction in (II) compared with (I). The elongation of the C4—N1 bond (Table 2) from the average value for conjugated C—N single bonds [1.370 Å; CSD; Allen, 2002) and the increase of the dihedral angle between such fragments of molecules can be explained by the steric interactions between the dimethylamine group and the H atom of the naphthalene ring. Similar values of bond lengths and dihedral angles have been found for substituted N,N-dimethylanilines and 1,8-naphthalenedicarboximide derivatives (Borbulevych et al., 2002; Kovalevsky et al., 2000). It can be concluded that compounds with aromatic systems such as naphthalene or anthracene do not have as strong a conjugation as similar compounds with benzene rings because of stronger steric interactions between bridging and aromatic parts of the molecules. The deviation of the nitro group from the plane of the substituted phenyl ring in (II) is more significant than the deviaiton in (I); the dihedral angle between these fragments is 9.0 (3)°. There is a weak intermolecular C9—H9A···O1 hydrogen bond in (II) between the H atom of a benzene ring and an O of the nitro group (Table 3), thus linking the molecules into centrosymmetric dimers. Similar hydrogen bonds have been reported previously (Zhang et al., 1998; Desiraju & Steiner, 1999; Huang et al., 2002). Molecules of both (I) and (II) form stacks, in which molecules are located in parallel planes that are not exactly aligned.
In order to investigate the influence of the crystal packing on the geometry of molecules in the crystals, a theoretical search for possible conformations by the molecular mechanics method (MM3; Allinger et al., 1989; Lii & Allinger, 1989) has been completed. It was confirmed that molecules of both (I) and (II) have to be non-planar in order to avoid steric interactions between neighboring H atoms of aromatic substituents and the conjugated bridge. The planarity of the molecules of (I) and (II) would lead to shortened intramolecular H···H distances (<2 Å), viz. H2A···H7A and H8A···H11A in (I), and H2A···H12A, H13A···H16A and H9A···H11A in (II). A search for the optimal geometry of molecules of (I) and (II) was performed using the stochastic search option in the MM3 program package. The results are summarized in Table 4. The comformation of the molecule of (II) corresponds to the second energy minimum found by MM3. The preferred conformation in this case is only slightly lower than the second one, which corresponds to the X-ray structure. However, in (I), the conformation that corresponds to the X-ray structure is higher in energy above the global minimum than in the case of (II) (Table 4). This result shows that the crystal environment influences the conformation in (I) more than in (II).