Synthesis, spectroscopic and Hirshfeld surface analysis and fluorescence studies of (2E,2′E)-3,3′-(1,4-phenyl­ene)bis­[1-(4-hy­droxy­phen­yl)prop-2-en-1-one] N,N-di­methyl­formamide disolvate

In the bis­chalcone mol­ecule, the central benzene and terminal hy­droxy­phenyl rings form a dihedral angle of 14.28 (11)° and the central C=C double bond adopts a trans conformation. In the crystal, the title mol­ecule and solvate are linked by O—H⋯O hydrogen bonds.

Abstract

In the bis­chalcone mol­ecule of the title compound, C₂₄H₁₈O₄·2C₃H₇NO, the central benzene and terminal hy­droxy­phenyl rings form a dihedral angle of 14.28 (11)° and the central C=C double bond adopts a trans configuration. In the crystal, the bis­chalcone and solvate mol­ecules are inter­connected via O—H⋯O hydrogen bonds, which were investigated by Hirshfeld surface analysis. Solid-state fluorescence was measured at λ_ex = 4400 Å. The emission wavelength appeared at 5510 Å, which corresponds to yellow light and the solid-state fluorescence quantum yield (F _f) is 0.18.

Chemical context  

The development of new fluorescent probes has attracted much attention because of their applications in a wide range of electronic and optoelectronic devices related to telecommunications, optical computing, optical storage and optical information processing. Fluorescence generally occurs when a fluorescent probe (fluoro­phore) resonantly absorbs electromagnetic radiation that promotes it to an excited electronic state; subsequent relaxation of the excited state results in the emission of light, in which a portion of the excitation energy is lost through heat or vibration, and the rest is emitted at longer wavelengths compared to the excitation radiation. For a given fluoro­phore, the fluorescence intensity is directly proportional to the intensity of the radiation received. Fluoro­phores can be identified and qu­anti­fied on the basis of their excitation and emission properties. Different materials may exhibit different colours and intensities of fluorescence despite seeming identical when observed in daylight conditions. In recent years, chalcones have been used in the field of material science as non-linear optical devices (Raghavendra et al., 2017 ▸; Chandra Shekhara Shetty et al., 2017 ▸), photorefractive polymers (Sun et al., 1999 ▸), optical limiting (Shettigar et al., 2006a ▸; Chandra Shekhara Shetty et al., 2016 ▸) and electrochemical sensing agents (Delavaux-Nicot et al., 2007 ▸). The α,β-unsaturated ketone (C=C—C=O) moiety in the chalcone skeleton plays a vital role in its biological activities (Kumar et al., 2013a ▸,b ▸). Apart from these biological activities, the photophysical properties of chalcone derivatives have also attracted considerable attention from both chemists and physicists. In view of the above and as a part of our ongoing work on such mol­ecules (Shettigar et al., 2006b ▸; Tejkiran et al., 2016 ▸; Pramodh et al., 2018 ▸; Naveen et al., 2017 ▸), we herein report the synthesis, structure determination, Hirshfeld surface analysis and fluorescence properties of (2E,2′E)-3,3′-(1,4-phenyl­ene)bis­[1-(4-hy­droxy­phen­yl)prop-2-en-1-one] N,N-di­methyl­formamide disolvate.

Structural commentary  

The asymmetric unit of the title compound comprises of half of the bis­chalcone mol­ecule, completed by inversion (symmetry operation 1 − x, 2 − y, −z) and a DMF mol­ecule (Fig. 1 ▸). The title compound crystallizes in the triclinic system with Z = 1 in space group P . The bis­chalcone mol­ecule is constructed from two individually planar rings (central benzene and terminal hy­droxy­phenyl rings) and a C=C—C(=O)—C enone bridge with the central C=C double bond in a trans configuration. The hy­droxy­phenyl (C1–C6) and benzene (C10–C12/C10A–C12A) rings are almost parallel to each other, subtending a dihedral angle of 14.28 (11)°. The enone fragment and its attached benzene ring are slightly twisted, as indicated by the torsion angles O1—C7—C8—C9 = −5.6 (4)° and C1—C6—C7—O1 = 1.7 (4)°. All bond lengths and angles of the titled compound are in normal ranges (Allen et al., 2002 ▸).

Figure 1.

The mol­ecular structure of the title compound, showing the atom-labelling scheme, with 40% probability displacement ellipsoids. Atoms labelled with the suffix A are generated by the symmetry operation 1 − x, 2 − y, −z.

Supra­molecular features  

In the crystal, the components are linked by O2—H2B⋯O3ⁱ hydrogen bonds, which connect the DMF solvate mol­ecules to both terminal 4-hy­droxy­phenyl rings of the main mol­ecules (Fig. 2 ▸, Table 1 ▸).

Figure 2.

Partial crystal packing, showing the O—H⋯O hydrogen bonds (Table 1 ▸) between the bis­chalcone and DMF solvate mol­ecules.

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H2B⋯O3i	0.99 (4)	1.63 (5)	2.592 (3)	162 (4)

Symmetry code: (i) .

Database survey  

A search of the Cambridge Structural Database (CSD, Version 5.39, last update November 2016; Groom et al., 2016 ▸) using (2E,2′E)-3,3′-(1,4-phenyl­ene)bis­(1-phenyl­prop-2-en-1-one) as main skeleton revealed the presence of four structures containing a similar bis-chalcone moiety to the title compound but with different substituents on the terminal phenyl rings, viz. 3,3′-(1,4-phenyl­ene)bis­[1-(X)prop-2-en-1-one], where X = 2-hy­droxy­phenyl (Gaur & Mishra, 2013 ▸), 4-chloro­phenyl (KIKFUG; Harrison et al., 2007 ▸), 4-meth­oxy­phenyl (Harrison et al., 2007a ▸) and 3,4-meth­oxy­phenyl (Harrison et al., 2007b ▸). In these four compounds, the dihedral angles between the central and terminal phenyl ring are in the range 10.91–46.27°. In the positional isomer of the title compound, the 2-hy­droxy­phenyl moiety forms a dihedral angle of 10.91° with the benzene ring, compared to 14.28 (11)° in the title compound. The difference may arise from the intra­molecular hydrogen bond between 2-hy­droxy­phenyl unit and the adjacent carbonyl moiety.

Hirshfeld surface analysis  

Hirshfeld surface analysis (McKinnon et al., 2004 ▸, 2007 ▸; Spackman & Jayatilaka, 2009 ▸; Spackman & McKinnon, 2002 ▸) was undertaken to qu­antify and give visual confirmation of the inter­molecular inter­action, and to explain the observed crystal structure. The d _norm surface plots, electrostatic potential and 2D fingerprint plots were generated by CrystalExplorer 3.1 (Wolff et al., 2012 ▸). The red spots on the d _norm surface arise as a result of the short inter­atomic contact; the positive electrostatic potential (blue regions) over the surface indicate hydrogen-donor potential, whereas the hydrogen-bond acceptors are represented by negative electrostatic potential (red regions). The d _norm surface plots and electrostatic potential of the title compound are shown in Fig. 3 ▸.

Figure 3.

d _norm and electrostatic potential mapped on Hirshfeld surfaces to visualize the inter­molecular contacts in the title compound. The mol­ecule in the ball-and-stick model is in the same orientation as for the Hirshfeld surface and electrostatic potential plots.

The surface shows a red spot on the hydroxyl and carbonyl groups of the main mol­ecule and solvate, respectively. This is a result of the O2—H2B⋯O3 hydrogen bonds present in the structure (Fig. 4 ▸ a). These observations are further confirmed by the respective electrostatic potential map in which the atoms involved in the formation of hydrogen bonds are seen as blue (hydrogen-bond donor) and red (hydrogen-bond acceptor) spots (Fig. 4 ▸ b). The corresponding fingerprint plots (FP) for Hirshfeld surfaces show characteristic pseudo-symmetry wings in the d_e and d_i diagonal axes in the overall 2D FP (Fig. 5 ▸ a). H⋯H contacts (i.e. dispersive forces) make the greatest percentage contribution to the Hirshfeld surface, followed by O⋯H/H⋯O and C⋯H/H⋯C contacts (Fig. 6 ▸). The H⋯H contacts appear as the largest region on the fingerprint plot with a high concentration in the middle region, at d _e = d _i ∼ 1.2 Å with an overall contribution to the Hirshfeld surface of 54.0% (Fig. 5 ▸ b). The reciprocal O⋯H/H⋯O inter­action (26.4%) appears as two sharp symmetric spikes in the FP plot, which is characteristic of a strong hydrogen-bonding inter­action, at d_e + d_i ≃ 1.7 Å (Fig. 5 ▸ c). Two symmetrical broad blunted wings corresponding to the C⋯H/H⋯C inter­action (with a 9.8% contribution) appear at d _e + d _i ≃ 3.0 Å (Fig. 5 ▸ d). Analysis of the close contact on the d _norm surface plot suggests that the C⋯H/H⋯C inter­action might arise from weak C—H⋯π and C—H⋯alkene inter­actions between the solvate and main mol­ecules (Fig. 7 ▸).

Figure 4.

(a) d _norm and (b) electrostatic potential mapped on Hirshfeld surfaces in order to visualize the inter­molecular O—H⋯O inter­actions in the title compound.

Figure 5.

The two-dimensional fingerprint plots for the title compound showing contributions from different contacts; the views on the right highlight the relevant surface patches associated with the specific contacts.

Figure 6.

Percentage contributions of the various inter­molecular contacts contributing to the Hirshfeld surfaces of the title compound.

Figure 7.

d _norm mapped on Hirshfeld surfaces to visualize the weak inter­molecular C—H⋯π and C—H⋯alkene inter­actions in the title compound.

Solid-state fluorescence studies  

A powder sample of the subject compound (0.72 mol) was heaped in the tray, covered with a quartz plate and was then fixed in the fluorescence spectrometer. The solid-state fluorescence properties were measured at the excitation wavelength (λ_ex) of 4400 Å, which was selected from the absorption spectrum of the compound. The difference in the relative intensities of reflections between the sample and MgO powder was calibrated using diffusion reflections in a non-absorbed wavelength, in the present case this was 6500 Å. Finally, the fluorescence quantum yield (F _f) was determined by Wrighton’s method and calculated according to the Φ_f = j _f/(ϒj _o − j) (Wrighton et al., 1974 ▸) where, j _f is the fluorescence intensity of the sample, ϒ the calibration factor, j ₀ the back-scattered intensity of excitation light from a blank (here MgO) and j the back-scattered intensity of a loaded sample. The solid-state excitation and emission spectrum of the title compound (λ_ex at 4400 Å) is shown in Fig. 8 ▸. The emission wavelength (blue line) appears at 5510 Å, which corresponds to yellow light. The solid-state fluorescence quantum yield (F _f) of the title compound is 0.18.

Figure 8.

Solid-state excitation and emission spectrum for the title compound

Synthesis and crystallization  

A mixture of corresponding 4-hy­droxy­aceto­phenone 0.02 mol) and terephthaldi­aldehyde (0.01 mol) was dissolved in methanol (20 mL). A catalytic amount of NaOH was added to the solution dropwise with vigorous stirring. The reaction mixture was stirred for about 5–6 h at room temperature. The resultant crude product was filtered, washed successively with distilled water and recrystallized from acetone solution. Crystals suitable for X-ray diffraction studies were obtained by the slow evaporation technique using DMF as solvent. Yield: 85%, m.p. = 544–546 K.

FT–IR [ATR (solid) cm⁻¹]: 3193 (O—H, ν), 3193 (Ar, C—H, ν), 2945 (methyl, C—H, νs), 2884 (methyl, C–H, ν), 1605 (C=O, ν), 1586, 1336 (Ar, C=C, ν), 1221 (C—O, ν), 1169 (C—N, ν). ¹H NMR (500 MHz, DMSO): δ (ppm) 8.120–8.103 (d, 4H, J = 8.7 Hz, ¹CH, ⁵CH), 8.028–7.997 (d, 2H, J = 15.6 Hz, ⁸CH), 7.964 (s, 4H, ¹¹CH, ¹²CH), 7.737–7.706 (d, 2H, J = 15.6 Hz, ⁹CH), 6.931–6.914 (d, 4H, J = 8.7 Hz, ²CH, ⁴CH); ¹³C NMR (125 MHz, DMSO): δ ppm 187.05 (C7), 162.29 (C3), 141.86 (C9), 136.65 (C10), 131.28 (C1, C5), 129.92 (C6), 129.19 (C11, C12), 123.05 (C8), 115.39 (C2, C4).

Refinement  

Crystal data, data collection and structure refinement details are summarized in Table 2 ▸. The O-bound H atom was located in a difference-Fourier map and refined freely. C–bound H atoms were positioned geometrically [C—H = 0.93–0.96 Å] and refined using a riding model with U _iso(H) = 1.5U _eq(C–meth­yl) and 1.2U _eq(C) for other H atoms.

Table 2. Experimental details.

Crystal data
Chemical formula	C24H18O4·2C3H7NO
M r	516.57
Crystal system, space group	Triclinic, P
Temperature (K)	294
a, b, c (Å)	6.0569 (5), 9.5801 (5), 11.9941 (8)
α, β, γ (°)	72.867 (2), 84.649 (2), 86.710 (2)
V (Å3)	661.86 (8)
Z	1
Radiation type	Mo Kα
μ (mm−1)	0.09
Crystal size (mm)	0.25 × 0.24 × 0.10
Data collection
Diffractometer	Bruker APEXII DUO CCD area-detector
Absorption correction	Multi-scan (SADABS; Bruker, 2012 ▸)
T min, T max	0.961, 0.991
No. of measured, independent and observed [I > 2σ(I)] reflections	21963, 3039, 1944
R int	0.043
(sin θ/λ)max (Å−1)	0.650
Refinement
R[F 2 > 2σ(F 2)], wR(F 2), S	0.057, 0.177, 1.07
No. of reflections	3039
No. of parameters	178
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å−3)	0.17, −0.19

Computer programs: APEX2 and SAINT (Bruker, 2012 ▸), SHELXS97 (Sheldrick, 2008 ▸), SHELXL2013 (Sheldrick, 2015 ▸), Mercury (Macrae et al., 2006 ▸) and PLATON (Spek, 2009 ▸).

Supplementary Material

CCDC reference: 1449629

Additional supporting information: crystallographic information; 3D view; checkCIF report

supplementary crystallographic information

Crystal data

C24H18O4·2C3H7NO	Z = 1
Mr = 516.57	F(000) = 274
Triclinic, P1	Dx = 1.296 Mg m−3
a = 6.0569 (5) Å	Mo Kα radiation, λ = 0.71073 Å
b = 9.5801 (5) Å	Cell parameters from 4190 reflections
c = 11.9941 (8) Å	θ = 2.4–23.5°
α = 72.867 (2)°	µ = 0.09 mm−1
β = 84.649 (2)°	T = 294 K
γ = 86.710 (2)°	Block, colourless
V = 661.86 (8) Å3	0.25 × 0.24 × 0.10 mm

Data collection

Bruker APEXII DUO CCD area-detector diffractometer	3039 independent reflections
Radiation source: fine-focus sealed tube	1944 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.043
φ and ω scans	θmax = 27.5°, θmin = 1.8°
Absorption correction: multi-scan (SADABS; Bruker, 2012)	h = −7→7
Tmin = 0.961, Tmax = 0.991	k = −12→12
21963 measured reflections	l = −15→15

Refinement

Refinement on F2	0 restraints
Least-squares matrix: full	Hydrogen site location: mixed
R[F2 > 2σ(F2)] = 0.057	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.177	w = 1/[σ2(Fo2) + (0.0694P)2 + 0.2543P] where P = (Fo2 + 2Fc2)/3
S = 1.07	(Δ/σ)max < 0.001
3039 reflections	Δρmax = 0.17 e Å−3
178 parameters	Δρmin = −0.19 e Å−3

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
O1	−0.1262 (3)	0.5766 (2)	0.23944 (17)	0.0750 (6)
O2	0.2445 (3)	0.0650 (2)	0.64822 (17)	0.0793 (6)
H2B	0.108 (7)	0.010 (5)	0.682 (4)	0.145 (15)*
C1	−0.0487 (4)	0.3283 (3)	0.4223 (2)	0.0545 (6)
H1A	−0.1859	0.3421	0.3911	0.065*
C2	−0.0096 (4)	0.2057 (3)	0.5127 (2)	0.0571 (6)
H2A	−0.1197	0.1376	0.5423	0.069*
C3	0.1943 (4)	0.1834 (3)	0.5599 (2)	0.0542 (6)
C4	0.3540 (4)	0.2863 (3)	0.5152 (2)	0.0643 (7)
H4A	0.4909	0.2727	0.5468	0.077*
C5	0.3131 (4)	0.4087 (3)	0.4244 (2)	0.0557 (6)
H5A	0.4233	0.4767	0.3951	0.067*
C6	0.1110 (3)	0.4324 (2)	0.37597 (18)	0.0460 (5)
C7	0.0568 (4)	0.5610 (2)	0.2773 (2)	0.0527 (6)
C8	0.2297 (4)	0.6688 (2)	0.2225 (2)	0.0552 (6)
H8A	0.3635	0.6600	0.2566	0.066*
C9	0.2000 (4)	0.7762 (2)	0.1276 (2)	0.0503 (5)
H9A	0.0634	0.7814	0.0968	0.060*
C10	0.3566 (3)	0.8892 (2)	0.06404 (18)	0.0452 (5)
C11	0.5544 (4)	0.9078 (2)	0.1063 (2)	0.0515 (6)
H11A	0.5925	0.8463	0.1781	0.062*
C12	0.3042 (4)	0.9840 (2)	−0.0435 (2)	0.0513 (6)
H12A	0.1716	0.9740	−0.0733	0.062*
N1	0.3441 (3)	0.2611 (2)	0.16532 (17)	0.0539 (5)
O3	0.0634 (3)	0.1066 (2)	0.23142 (17)	0.0752 (6)
C13	0.2500 (4)	0.1452 (3)	0.2375 (2)	0.0610 (6)
H13A	0.3312	0.0880	0.2977	0.073*
C14	0.5659 (4)	0.3002 (3)	0.1757 (3)	0.0788 (8)
H14A	0.6290	0.2276	0.2392	0.118*
H14B	0.5611	0.3935	0.1906	0.118*
H14C	0.6553	0.3055	0.1042	0.118*
C15	0.2266 (5)	0.3526 (3)	0.0692 (3)	0.0767 (8)
H15A	0.0810	0.3160	0.0728	0.115*
H15B	0.3065	0.3518	−0.0036	0.115*
H15C	0.2142	0.4508	0.0746	0.115*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
O1	0.0553 (10)	0.0705 (12)	0.0816 (13)	−0.0128 (9)	−0.0211 (9)	0.0120 (10)
O2	0.0605 (11)	0.0750 (13)	0.0769 (13)	−0.0169 (9)	−0.0191 (9)	0.0242 (10)
C1	0.0427 (12)	0.0581 (14)	0.0556 (13)	−0.0102 (10)	−0.0092 (10)	−0.0021 (11)
C2	0.0456 (12)	0.0556 (14)	0.0594 (14)	−0.0185 (10)	−0.0057 (10)	0.0034 (11)
C3	0.0496 (12)	0.0534 (13)	0.0500 (13)	−0.0106 (10)	−0.0049 (10)	0.0018 (10)
C4	0.0446 (12)	0.0718 (17)	0.0646 (15)	−0.0158 (11)	−0.0162 (11)	0.0047 (13)
C5	0.0469 (12)	0.0555 (14)	0.0556 (14)	−0.0185 (10)	−0.0063 (10)	0.0018 (11)
C6	0.0460 (11)	0.0456 (12)	0.0431 (11)	−0.0080 (9)	−0.0033 (9)	−0.0065 (9)
C7	0.0500 (13)	0.0511 (13)	0.0525 (13)	−0.0072 (10)	−0.0079 (10)	−0.0062 (10)
C8	0.0517 (13)	0.0524 (13)	0.0545 (14)	−0.0100 (10)	−0.0106 (10)	−0.0012 (11)
C9	0.0473 (12)	0.0462 (12)	0.0516 (13)	−0.0047 (9)	−0.0045 (9)	−0.0047 (10)
C10	0.0476 (11)	0.0393 (11)	0.0445 (12)	−0.0030 (9)	−0.0027 (9)	−0.0060 (9)
C11	0.0558 (13)	0.0463 (12)	0.0445 (12)	−0.0046 (10)	−0.0115 (10)	0.0018 (9)
C12	0.0496 (12)	0.0490 (13)	0.0511 (13)	−0.0069 (10)	−0.0127 (10)	−0.0047 (10)
N1	0.0451 (10)	0.0505 (11)	0.0621 (12)	−0.0071 (8)	−0.0028 (9)	−0.0097 (9)
O3	0.0622 (11)	0.0740 (12)	0.0797 (13)	−0.0249 (9)	0.0030 (9)	−0.0060 (10)
C13	0.0598 (15)	0.0552 (15)	0.0622 (15)	−0.0043 (12)	−0.0051 (11)	−0.0074 (12)
C14	0.0536 (15)	0.083 (2)	0.104 (2)	−0.0178 (14)	−0.0046 (14)	−0.0301 (17)
C15	0.0751 (18)	0.0691 (18)	0.0739 (19)	−0.0094 (14)	−0.0138 (14)	0.0016 (14)

Geometric parameters (Å, º)

O1—C7	1.221 (3)	C9—H9A	0.9300
O2—C3	1.347 (3)	C10—C11	1.383 (3)
O2—H2B	0.99 (4)	C10—C12	1.393 (3)
C1—C2	1.370 (3)	C11—C12i	1.377 (3)
C1—C6	1.387 (3)	C11—H11A	0.9300
C1—H1A	0.9300	C12—C11i	1.377 (3)
C2—C3	1.386 (3)	C12—H12A	0.9300
C2—H2A	0.9300	N1—C13	1.312 (3)
C3—C4	1.377 (3)	N1—C14	1.441 (3)
C4—C5	1.374 (3)	N1—C15	1.445 (3)
C4—H4A	0.9300	O3—C13	1.224 (3)
C5—C6	1.382 (3)	C13—H13A	0.9300
C5—H5A	0.9300	C14—H14A	0.9600
C6—C7	1.481 (3)	C14—H14B	0.9600
C7—C8	1.480 (3)	C14—H14C	0.9600
C8—C9	1.310 (3)	C15—H15A	0.9600
C8—H8A	0.9300	C15—H15B	0.9600
C9—C10	1.466 (3)	C15—H15C	0.9600
C3—O2—H2B	110 (2)	C11—C10—C12	117.98 (19)
C2—C1—C6	121.8 (2)	C11—C10—C9	123.14 (19)
C2—C1—H1A	119.1	C12—C10—C9	118.88 (19)
C6—C1—H1A	119.1	C12i—C11—C10	121.0 (2)
C1—C2—C3	119.8 (2)	C12i—C11—H11A	119.5
C1—C2—H2A	120.1	C10—C11—H11A	119.5
C3—C2—H2A	120.1	C11i—C12—C10	121.0 (2)
O2—C3—C4	118.0 (2)	C11i—C12—H12A	119.5
O2—C3—C2	123.0 (2)	C10—C12—H12A	119.5
C4—C3—C2	119.0 (2)	C13—N1—C14	122.5 (2)
C5—C4—C3	120.6 (2)	C13—N1—C15	119.9 (2)
C5—C4—H4A	119.7	C14—N1—C15	117.6 (2)
C3—C4—H4A	119.7	O3—C13—N1	124.9 (2)
C4—C5—C6	121.1 (2)	O3—C13—H13A	117.6
C4—C5—H5A	119.4	N1—C13—H13A	117.6
C6—C5—H5A	119.4	N1—C14—H14A	109.5
C5—C6—C1	117.6 (2)	N1—C14—H14B	109.5
C5—C6—C7	123.92 (19)	H14A—C14—H14B	109.5
C1—C6—C7	118.46 (19)	N1—C14—H14C	109.5
O1—C7—C8	120.2 (2)	H14A—C14—H14C	109.5
O1—C7—C6	120.7 (2)	H14B—C14—H14C	109.5
C8—C7—C6	119.10 (19)	N1—C15—H15A	109.5
C9—C8—C7	122.0 (2)	N1—C15—H15B	109.5
C9—C8—H8A	119.0	H15A—C15—H15B	109.5
C7—C8—H8A	119.0	N1—C15—H15C	109.5
C8—C9—C10	127.7 (2)	H15A—C15—H15C	109.5
C8—C9—H9A	116.2	H15B—C15—H15C	109.5
C10—C9—H9A	116.2
C6—C1—C2—C3	−0.1 (4)	C1—C6—C7—C8	−176.6 (2)
C1—C2—C3—O2	−179.5 (2)	O1—C7—C8—C9	−5.6 (4)
C1—C2—C3—C4	0.5 (4)	C6—C7—C8—C9	172.7 (2)
O2—C3—C4—C5	179.4 (2)	C7—C8—C9—C10	−179.5 (2)
C2—C3—C4—C5	−0.6 (4)	C8—C9—C10—C11	−8.4 (4)
C3—C4—C5—C6	0.3 (4)	C8—C9—C10—C12	172.3 (2)
C4—C5—C6—C1	0.0 (4)	C12—C10—C11—C12i	−0.5 (4)
C4—C5—C6—C7	−179.3 (2)	C9—C10—C11—C12i	−179.8 (2)
C2—C1—C6—C5	−0.1 (4)	C11—C10—C12—C11i	0.5 (4)
C2—C1—C6—C7	179.3 (2)	C9—C10—C12—C11i	179.8 (2)
C5—C6—C7—O1	−179.0 (2)	C14—N1—C13—O3	−179.1 (3)
C1—C6—C7—O1	1.7 (4)	C15—N1—C13—O3	−0.8 (4)
C5—C6—C7—C8	2.7 (4)

Symmetry code: (i) −x+1, −y+2, −z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2B···O3ii	0.99 (4)	1.63 (5)	2.592 (3)	162 (4)

Symmetry code: (ii) −x, −y, −z+1.

Funding Statement

This work was funded by Ministry of Higher Education, Malaysia grant MyBrain15 (MyPhD) to Huey Chong Kwong. Universiti Sains Malaysia grant 1001/PFIZIK/811278.