organic compounds
An orthorhombic polymorph of N1,N4-diphenyl-3,6-bis(phenylimino)cyclohexa-1,4-diene-1,4-diamine
aDepartment of Chemistry, Graduate School of Science and Engineering, Saitama University, Shimo-Okubo 255, Sakura-ku, Saitama 338-8570, Japan, and bComprehensive Analysis Center for Science, Saitama University, Shimo-Okubo 255, Sakura-ku, Saitama 338-8570, Japan
*Correspondence e-mail: fuji@chem.saitama-u.ac.jp
A new orthorhombic polymorph of the title compound, C30H24N4, with a density of 1.315 Mg m−3, has been obtained. The molecule is centrosymmetric with the centroid of the cyclohexa-1,4-diene ring located on an inversion center. The two unique benzene rings are almost perpendicular to each other [dihedral angle = 86.70 (6)°] and are oriented at dihedral angles of 30.79 (5) and 68.07 (5)° with respect to the central cyclohexadiene ring. In the crystal, π–π stacking is observed between the central cyclohexa-1,4-diene-1,4-diamine unit and a phenyl ring of a neighboring molecule [centroid–centroid distance = 3.7043 (7) Å]. The of the triclinic polymorph [Ohno et al. (2014). Acta Cryst. E70, o303–o304] showed chains running along the b-axis direction through weak C—H⋯π interactions.
CCDC reference: 992862
Related literature
For general background to the title compound, see: Kimish (1875). For the triclinic polymorph of the title compound, see: Ohno et al. (2014). For related structures, see: Siri & Braunstein (2000); Khramov et al. (2006); Boydston et al. (2006); Huang et al. (2008); Su et al. (2012). A calculation using Gaussian98 indicates that the triclinic form of the title compound is more stable, see: Frisch et al. (2001).
Experimental
Crystal data
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Data collection: SMART (Bruker, 2007); cell SAINT (Bruker, 2007); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL; molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: SHELXTL.
Supporting information
CCDC reference: 992862
10.1107/S1600536814006254/xu5776sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536814006254/xu5776Isup2.hkl
Supporting information file. DOI: 10.1107/S1600536814006254/xu5776Isup3.cml
The VIV complex [VIV(O)(η2-ox)(H2O)3] was purchased as "VO(ox).nH2O" from Wako Chemicals, and used without further purification. A solution of aniline (27.9 g, 300 mmol) in EtOH (50 cm3) was added to a solution of VO(ox).nH2O (1.13 g, 3.00 mmol) in a mixture of EtOH (50 cm3) and H2O (100 cm3). The reaction mixture was set aside for 2 weeks at room temperature in air. The precipitated crystals of I were filtered off, washed with H2O and EtOH, successively, and dried. Yield 1.34 g. (5.1%). 1H NMR / CDCl3: δ 8.22 (s, 2H, NH), 7.41–6.88 (m, 20H, PhH), 6.21 (s, 2H, CH). MALDI TOF MS: 441 (M+1). UV-vis / CH2Cl2, λ/nm (ε/M-1cm-1): 290 (46000), 379 (30000).
The H atoms of NH moiety was located from a Fourier difference map and refined isotropically. Other H atoms were placed at idealized positions with C—H = 0.95 Å, and refined in riding mode with Ueq(H) = 1.2Uiso(C).
Data collection: SMART (Bruker, 2007); cell
SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).C30H24N4 | F(000) = 928 |
Mr = 440.53 | Dx = 1.345 Mg m−3 |
Orthorhombic, Pbca | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ac 2ab | Cell parameters from 6200 reflections |
a = 9.1927 (5) Å | θ = 3.0–27.8° |
b = 12.4711 (7) Å | µ = 0.08 mm−1 |
c = 18.9806 (11) Å | T = 173 K |
V = 2176.0 (2) Å3 | Plate, orange |
Z = 4 | 0.35 × 0.30 × 0.10 mm |
Bruker SMART APEX CCD area-detector diffractometer | 2591 independent reflections |
Radiation source: fine-focus sealed tube | 2193 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.116 |
Detector resolution: 8.366 pixels mm-1 | θmax = 27.9°, θmin = 2.2° |
ϕ and ω scans | h = −12→11 |
Absorption correction: multi-scan (SADABS; Bruker, 2001) | k = −16→15 |
Tmin = 0.97, Tmax = 0.99 | l = −16→24 |
14830 measured 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)] = 0.046 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.133 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.09 | w = 1/[σ2(Fo2) + (0.073P)2 + 0.1882P] where P = (Fo2 + 2Fc2)/3 |
2591 reflections | (Δ/σ)max < 0.001 |
158 parameters | Δρmax = 0.31 e Å−3 |
0 restraints | Δρmin = −0.24 e Å−3 |
C30H24N4 | V = 2176.0 (2) Å3 |
Mr = 440.53 | Z = 4 |
Orthorhombic, Pbca | Mo Kα radiation |
a = 9.1927 (5) Å | µ = 0.08 mm−1 |
b = 12.4711 (7) Å | T = 173 K |
c = 18.9806 (11) Å | 0.35 × 0.30 × 0.10 mm |
Bruker SMART APEX CCD area-detector diffractometer | 2591 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2001) | 2193 reflections with I > 2σ(I) |
Tmin = 0.97, Tmax = 0.99 | Rint = 0.116 |
14830 measured reflections |
R[F2 > 2σ(F2)] = 0.046 | 0 restraints |
wR(F2) = 0.133 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.09 | Δρmax = 0.31 e Å−3 |
2591 reflections | Δρmin = −0.24 e Å−3 |
158 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. Least-squares planes (x,y,z in crystal coordinates) and deviations from them (* indicates atom used to define plane) - 4.5932 (0.0050) x + 6.9089 (0.0064) y + 12.6394 (0.0086) z = 6.3197 (0.0043) * 0.0005 (0.0006) C1 * -0.0005 (0.0006) C2 * 0.0005 (0.0006) C3 * -0.0005 (0.0006) C1_$1 * 0.0005 (0.0006) C2_$1 * -0.0005 (0.0006) C3_$1 Rms deviation of fitted atoms = 0.0005 - 5.6034 (0.0038) x + 5.0416 (0.0058) y + 12.9434 (0.0070) z = 2.9266 (0.0041) Angle to previous plane (with approximate e.s.d.) = 10.70 (0.08) * 0.0006 (0.0008) C10_$2 * -0.0066 (0.0008) C11_$2 * 0.0067 (0.0009) C12_$2 * -0.0008 (0.0009) C13_$2 * -0.0053 (0.0009) C14_$2 * 0.0053 (0.0008) C15_$2 Rms deviation of fitted atoms = 0.0049 - 4.5932 (0.0050) x + 6.9089 (0.0064) y + 12.6394 (0.0086) z = 6.3197 (0.0043) Angle to previous plane (with approximate e.s.d.) = 10.70 (0.08) * 0.0005 (0.0006) C1 * -0.0005 (0.0006) C2 * 0.0005 (0.0006) C3 * -0.0005 (0.0006) C1_$1 * 0.0005 (0.0006) C2_$1 * -0.0005 (0.0006) C3_$1 - 3.7228 (0.0017) C10_$2 - 3.4796 (0.0019) C11_$2 - 3.2849 (0.0018) C12_$2 Rms deviation of fitted atoms = 0.0005 - 4.5932 (0.0050) x + 6.9089 (0.0064) y + 12.6394 (0.0086) z = 6.3197 (0.0043) Angle to previous plane (with approximate e.s.d.) = 0.00 (0.10) * 0.0005 (0.0006) C1 * -0.0005 (0.0006) C2 * 0.0005 (0.0006) C3 * -0.0005 (0.0006) C1_$1 * 0.0005 (0.0006) C2_$1 * -0.0005 (0.0006) C3_$1 - 3.3572 (0.0015) C13_$2 - 3.6100 (0.0013) C14_$2 - 3.7830 (0.0014) C15_$2 Rms deviation of fitted atoms = 0.0005 - 7.4963 (0.0028) x + 1.7481 (0.0065) y + 10.6592 (0.0082) z = 4.5261 (0.0067) Angle to previous plane (with approximate e.s.d.) = 30.79 (0.06) * 0.0118 (0.0008) C4 * -0.0134 (0.0008) C5 * 0.0021 (0.0009) C6 * 0.0111 (0.0009) C7 * -0.0128 (0.0009) C8 * 0.0013 (0.0009) C9 Rms deviation of fitted atoms = 0.0101 5.6034 (0.0038) x + 5.0416 (0.0058) y + 12.9434 (0.0071) z = 8.2491 (0.0021) Angle to previous plane (with approximate e.s.d.) = 86.71 (0.03) * 0.0006 (0.0008) C10 * -0.0066 (0.0008) C11 * 0.0067 (0.0009) C12 * -0.0008 (0.0009) C13 * -0.0053 (0.0009) C14 * 0.0053 (0.0008) C15 Rms deviation of fitted atoms = 0.004 |
x | y | z | Uiso*/Ueq | ||
C1 | 0.12006 (12) | −0.00788 (8) | 0.54798 (6) | 0.0209 (3) | |
C2 | 0.10916 (12) | 0.08101 (8) | 0.49535 (6) | 0.0206 (3) | |
C3 | −0.01449 (12) | 0.08355 (9) | 0.44911 (6) | 0.0215 (3) | |
H3 | −0.0224 | 0.1398 | 0.4156 | 0.026* | |
C4 | 0.29282 (12) | −0.06850 (9) | 0.64289 (6) | 0.0219 (3) | |
C5 | 0.27035 (13) | −0.17924 (10) | 0.64288 (6) | 0.0256 (3) | |
H5 | 0.2148 | −0.2119 | 0.6065 | 0.031* | |
C6 | 0.32978 (14) | −0.24128 (10) | 0.69630 (7) | 0.0301 (3) | |
H6 | 0.3123 | −0.3164 | 0.6968 | 0.036* | |
C7 | 0.41411 (15) | −0.19588 (10) | 0.74902 (6) | 0.0321 (3) | |
H7 | 0.4531 | −0.2392 | 0.7856 | 0.039* | |
C8 | 0.44080 (15) | −0.08662 (10) | 0.74762 (6) | 0.0314 (3) | |
H8 | 0.5013 | −0.0551 | 0.7825 | 0.038* | |
C9 | 0.37968 (13) | −0.02321 (9) | 0.69556 (6) | 0.0264 (3) | |
H9 | 0.3969 | 0.0519 | 0.6956 | 0.032* | |
C10 | 0.21200 (12) | 0.24083 (9) | 0.45179 (6) | 0.0223 (3) | |
C11 | 0.11033 (13) | 0.32190 (10) | 0.46367 (6) | 0.0262 (3) | |
H11 | 0.0366 | 0.3124 | 0.4982 | 0.031* | |
C12 | 0.11658 (14) | 0.41614 (9) | 0.42529 (7) | 0.0280 (3) | |
H12 | 0.0483 | 0.4717 | 0.4343 | 0.034* | |
C13 | 0.22200 (14) | 0.43007 (10) | 0.37364 (7) | 0.0288 (3) | |
H13 | 0.2254 | 0.4945 | 0.3469 | 0.035* | |
C14 | 0.32205 (14) | 0.34921 (10) | 0.36147 (7) | 0.0291 (3) | |
H14 | 0.3940 | 0.3582 | 0.3260 | 0.035* | |
C15 | 0.31853 (13) | 0.25534 (9) | 0.40038 (6) | 0.0254 (3) | |
H15 | 0.3887 | 0.2008 | 0.3921 | 0.031* | |
H1 | 0.2849 (18) | 0.0610 (13) | 0.5831 (8) | 0.030 (4)* | |
N1 | 0.23876 (11) | 0.00087 (8) | 0.59090 (5) | 0.0248 (2) | |
N2 | 0.21592 (10) | 0.14848 (8) | 0.49516 (5) | 0.0236 (2) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0178 (5) | 0.0226 (5) | 0.0223 (5) | 0.0024 (4) | −0.0001 (4) | −0.0009 (4) |
C2 | 0.0181 (5) | 0.0207 (5) | 0.0231 (5) | 0.0007 (4) | 0.0008 (4) | −0.0010 (4) |
C3 | 0.0197 (5) | 0.0220 (5) | 0.0229 (5) | 0.0005 (4) | −0.0010 (4) | 0.0020 (4) |
C4 | 0.0160 (5) | 0.0264 (6) | 0.0234 (5) | 0.0013 (4) | 0.0005 (4) | 0.0022 (4) |
C5 | 0.0198 (6) | 0.0265 (6) | 0.0305 (6) | −0.0003 (4) | −0.0015 (4) | −0.0008 (4) |
C6 | 0.0243 (6) | 0.0266 (6) | 0.0393 (7) | 0.0012 (5) | 0.0003 (5) | 0.0055 (5) |
C7 | 0.0288 (7) | 0.0374 (7) | 0.0302 (6) | 0.0062 (5) | −0.0025 (5) | 0.0084 (5) |
C8 | 0.0267 (7) | 0.0395 (7) | 0.0279 (6) | 0.0026 (5) | −0.0061 (5) | −0.0014 (5) |
C9 | 0.0233 (6) | 0.0267 (6) | 0.0291 (6) | 0.0007 (4) | −0.0032 (4) | −0.0007 (4) |
C10 | 0.0183 (5) | 0.0222 (5) | 0.0264 (6) | −0.0041 (4) | −0.0045 (4) | 0.0007 (4) |
C11 | 0.0201 (6) | 0.0287 (6) | 0.0297 (6) | −0.0013 (4) | 0.0015 (4) | 0.0006 (4) |
C12 | 0.0225 (6) | 0.0250 (6) | 0.0364 (7) | 0.0025 (4) | −0.0017 (5) | −0.0001 (5) |
C13 | 0.0282 (6) | 0.0251 (6) | 0.0330 (6) | −0.0032 (5) | −0.0028 (5) | 0.0064 (5) |
C14 | 0.0244 (6) | 0.0326 (6) | 0.0301 (6) | −0.0035 (5) | 0.0032 (5) | 0.0038 (5) |
C15 | 0.0202 (6) | 0.0264 (6) | 0.0296 (6) | 0.0006 (4) | −0.0014 (4) | −0.0002 (4) |
N1 | 0.0217 (5) | 0.0237 (5) | 0.0290 (5) | −0.0051 (4) | −0.0059 (4) | 0.0044 (4) |
N2 | 0.0194 (5) | 0.0227 (5) | 0.0286 (5) | −0.0017 (4) | −0.0019 (4) | 0.0021 (4) |
C1—C3i | 1.3547 (16) | C8—C9 | 1.3847 (17) |
C1—N1 | 1.3662 (15) | C8—H8 | 0.9500 |
C1—C2 | 1.4957 (15) | C9—H9 | 0.9500 |
C2—N2 | 1.2927 (14) | C10—C15 | 1.3942 (17) |
C2—C3 | 1.4365 (15) | C10—C11 | 1.3952 (17) |
C3—C1i | 1.3547 (16) | C10—N2 | 1.4160 (14) |
C3—H3 | 0.9500 | C11—C12 | 1.3840 (17) |
C4—C5 | 1.3964 (16) | C11—H11 | 0.9500 |
C4—C9 | 1.3985 (16) | C12—C13 | 1.3893 (18) |
C4—N1 | 1.4032 (15) | C12—H12 | 0.9500 |
C5—C6 | 1.3874 (17) | C13—C14 | 1.3842 (18) |
C5—H5 | 0.9500 | C13—H13 | 0.9500 |
C6—C7 | 1.3866 (19) | C14—C15 | 1.3846 (16) |
C6—H6 | 0.9500 | C14—H14 | 0.9500 |
C7—C8 | 1.3848 (19) | C15—H15 | 0.9500 |
C7—H7 | 0.9500 | N1—H1 | 0.874 (17) |
C3i—C1—N1 | 127.12 (10) | C8—C9—H9 | 119.6 |
C3i—C1—C2 | 119.71 (10) | C4—C9—H9 | 119.6 |
N1—C1—C2 | 113.12 (10) | C15—C10—C11 | 119.31 (10) |
N2—C2—C3 | 125.78 (10) | C15—C10—N2 | 119.63 (10) |
N2—C2—C1 | 115.69 (10) | C11—C10—N2 | 120.83 (10) |
C3—C2—C1 | 118.51 (10) | C12—C11—C10 | 120.17 (11) |
C1i—C3—C2 | 121.78 (10) | C12—C11—H11 | 119.9 |
C1i—C3—H3 | 119.1 | C10—C11—H11 | 119.9 |
C2—C3—H3 | 119.1 | C11—C12—C13 | 120.44 (11) |
C5—C4—C9 | 118.94 (10) | C11—C12—H12 | 119.8 |
C5—C4—N1 | 123.87 (10) | C13—C12—H12 | 119.8 |
C9—C4—N1 | 117.12 (10) | C14—C13—C12 | 119.34 (11) |
C6—C5—C4 | 119.55 (11) | C14—C13—H13 | 120.3 |
C6—C5—H5 | 120.2 | C12—C13—H13 | 120.3 |
C4—C5—H5 | 120.2 | C13—C14—C15 | 120.76 (11) |
C7—C6—C5 | 121.32 (11) | C13—C14—H14 | 119.6 |
C7—C6—H6 | 119.3 | C15—C14—H14 | 119.6 |
C5—C6—H6 | 119.3 | C14—C15—C10 | 119.96 (11) |
C8—C7—C6 | 119.14 (11) | C14—C15—H15 | 120.0 |
C8—C7—H7 | 120.4 | C10—C15—H15 | 120.0 |
C6—C7—H7 | 120.4 | C1—N1—C4 | 130.77 (10) |
C9—C8—C7 | 120.25 (12) | C1—N1—H1 | 110.7 (10) |
C9—C8—H8 | 119.9 | C4—N1—H1 | 118.5 (10) |
C7—C8—H8 | 119.9 | C2—N2—C10 | 120.77 (10) |
C8—C9—C4 | 120.74 (11) | ||
C3i—C1—C2—N2 | −178.63 (10) | N2—C10—C11—C12 | 173.81 (11) |
N1—C1—C2—N2 | 3.91 (14) | C10—C11—C12—C13 | 1.35 (18) |
C3i—C1—C2—C3 | 0.14 (17) | C11—C12—C13—C14 | −0.79 (19) |
N1—C1—C2—C3 | −177.31 (10) | C12—C13—C14—C15 | −0.37 (19) |
N2—C2—C3—C1i | 178.50 (11) | C13—C14—C15—C10 | 0.95 (18) |
C1—C2—C3—C1i | −0.14 (17) | C11—C10—C15—C14 | −0.38 (17) |
C9—C4—C5—C6 | 2.39 (17) | N2—C10—C15—C14 | −175.02 (10) |
N1—C4—C5—C6 | 179.27 (11) | C3i—C1—N1—C4 | 7.7 (2) |
C4—C5—C6—C7 | −1.51 (18) | C2—C1—N1—C4 | −175.09 (11) |
C5—C6—C7—C8 | −0.8 (2) | C5—C4—N1—C1 | 26.84 (19) |
C6—C7—C8—C9 | 2.2 (2) | C9—C4—N1—C1 | −156.22 (12) |
C7—C8—C9—C4 | −1.33 (19) | C3—C2—N2—C10 | 6.60 (17) |
C5—C4—C9—C8 | −1.00 (18) | C1—C2—N2—C10 | −174.73 (9) |
N1—C4—C9—C8 | −178.09 (11) | C15—C10—N2—C2 | −119.41 (12) |
C15—C10—C11—C12 | −0.76 (17) | C11—C10—N2—C2 | 66.04 (14) |
Symmetry code: (i) −x, −y, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C30H24N4 |
Mr | 440.53 |
Crystal system, space group | Orthorhombic, Pbca |
Temperature (K) | 173 |
a, b, c (Å) | 9.1927 (5), 12.4711 (7), 18.9806 (11) |
V (Å3) | 2176.0 (2) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.08 |
Crystal size (mm) | 0.35 × 0.30 × 0.10 |
Data collection | |
Diffractometer | Bruker SMART APEX CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 2001) |
Tmin, Tmax | 0.97, 0.99 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 14830, 2591, 2193 |
Rint | 0.116 |
(sin θ/λ)max (Å−1) | 0.658 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.046, 0.133, 1.09 |
No. of reflections | 2591 |
No. of parameters | 158 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.31, −0.24 |
Computer programs: SMART (Bruker, 2007), SAINT (Bruker, 2007), SHELXTL (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 2012).
Acknowledgements
This work was supported by the programs of the Grants-in-Aid for Scientific Research (to TF, No. 23510115) from the Japan Society for the Promotion of Science.
References
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N1,N4-Diphenyl-3,6-bis(phenylimino)cyclohexa-1,4-diene-1,4-diamine (I) was synthesized as early as in 1875 (Kimish, 1875) and called azophenine. Recently derivatives of I were prepared and these molecular structures were reported (Siri & Braunstein, 2000; Khramov et al., 2006; Boydston et al., 2006; Huang et al., 2008; Su et al., 2012). Previously, we reported the molecular structure of I in triclinic P-1 space group, which is obtained from an oxidation reaction of aniline in the presence of [VIV(O)(η2-ox)(H2O)3] (ox2- = oxalate) in a mixture of EtOH and H2O (Ohno et al., 2014).
We obtained the crystals of I in orthorhombic Pbca space group from a reaction with aniline and [VIV(O)(η2-ox)(H2O)3] and will report here its molecular and crystal structures. This crystal is a porymorph of the previously reported triclinic structure, which showed one-dimensional chains running along the b-axis direction through weak C—H···π interactions in the crystal.
The crystals contain only I. The main structural difference between the polymorphs of I lies in the orientation of phenyl rings (Figure 2). The neighboring phenyl rings in orthorhombic polymorph of I locate near perpendicular with each other, where the dihedral angle between C(4)—C(5)—C(6)—C(7)—C(8)—C(9) and C(10 A)—C(11 A)—C(12 A)—C(13 A)—C(14 A)—C(15 A) phenyl rings is 86.71°. On the other hand, the dihedral angles between neighboring phenyl rings in triclinic polymorph of I are 29.46 and 19.69° for between C(7)—C(8)—C(9)—C(10)—C(11)—C(12) and C(25)—C(26)—C(27)—C(28)—C(29)—C(30) phenyl rings and C(13)—C(14)—C(15)—C(16)— C(17)—C(18) and C(19)—C(20)—C(21)—C(22)—C(23)—C(24) ones, respectively.
Packing structure of the orthorhombic polymorph of I represented two-dimensional sheets through intermolecular π–π interaction, where the distances between the phenyl ring C(10)—C(11)—C(12)—C(13)—C(14)—C(15) and the central six-membered ring of adjacent molecule C(1)—C(2)—C(3)—C(1 A)—C(2 A)—C(3 A) is about 3.54 Å (the symmetry code: -x + 0.5, y - 0.5, z) and the dihedral angle between them is 10.70 (8)° (Figure 3).
Calculations using Gaussian98 (Frisch et al., 2001) with a B3LYP/6–31 G(d) set of parameters for polymorphs indicate that the triclinic form is more stable than the monoclinic form by approximately 10 kJ mol-1.