Conformational dimorphism of 2,2'-methyl-enebis(isoindoline-1,3-dione).

In this study, a new monoclinic polymorph (space group C2/c) of 2,2'-methyl-enebis(isoindoline-1,3-dione), C17H10N2O4, is reported and compared to the previously reported triclinic polymorph (space group P ). Similarly, both polymorphs consist of a unique mol-ecule in the asymmetric unit (Z' = 1). The mol-ecular conformations of the two polymorphs are very similar, as shown by the r.m.s. deviation of 0.368 Å (excluding all H atoms). The inter-molecular inter-actions of both polymorphs are described along with the Hirshfeld surface analysis, and the lattice energies are calculated.

Chemical context

Phthalimide (or isoindoline-1,3-dione) derivatives with five-membered N-heterocycles have been proven to exhibit significant biological and pharmaceutical activities, and have also been used as dyes and heat-resistant polymers in industry (Chidan Kumar et al., 2015 ▸; Then et al., 2018 ▸). The first reported crystal structure of 2,2′-methyl­enebis(isoindoline-1,3-dione) (1α; Jiang et al., 2007 ▸) crystallizes in the centrosymmetric triclinic space group P [a = 7.6660 (9) Å, b = 9.5810 (8) Å, c = 10.2780 (6) Å, α = 104.325 (3)°, β = 99.768 (4)°, γ = 96.030 (3)°, Z = 2, Z′ = 1 and V = 712.23 (11) Å3; Cambridge Structural Database (CSD; Groom et al., 2016 ▸) refcode SINDID]. In this article, we report the second polymorphic form (1β) of 2,2′-methyl­enebis(isoindoline-1,3-dione) with Z′ = 1 and compare its properties with those of 1α. According to the Online Dictionary of Crystallography, polymorphism is the phenomenon in which the same chemical compound exhibits different crystal structures (IUCr, 2018 ▸).

Structural commentary

The asymmetric units of polymorphs 1α and 1β (Fig. 1 ▸) each contain a unique mol­ecule of 2,2′-methyl­enebis(isoindoline-1,3-dione), which consists of two phthalimide groups and a methyl­ene bridge. The phthalimide groups are nearly planar with maximum deviations of 0.029 (1) and 0.059 (1) Å for 1α, and 0.040 (4) and 0.064 (3) Å for 1β. There are two degrees of freedom to characterize the mol­ecular conformations of 1α and 1β: these are the torsion angles C1—N1—C9—N2 [106.7 (1) and 117.4 (3)°, respectively] and N1—C9—N2—C10 [109.2 (1) and 117.6 (3)°, respectively]. Generally, the mol­ecule of 1β deviates only slightly from that of 1α, as indicated by a r.m.s. deviation of 0.368 Å (excluding all H atoms) (Fig. 2 ▸). The mean planes of the phthalimide rings for 1β make a dihedral angle of 76.12 (8)°, which is smaller than that of 88.96 (4)° observed in polymorph 1α. The calculated density and Kitaigorodskii packing index (Spek, 2009 ▸) for 1β (1.469 Mg m−3 and 70.0%) are slightly higher than those observed for 1α (1.428 Mg m−3 and 69.0%).

Figure 1

Mol­ecular structure of 1β with atom labels and 30% probability displacement ellipsoids.

Figure 2

An overlay diagram for the mol­ecules of 1α (red) and 1β (blue).

Supra­molecular features

The crystal packing of 1α features weak inter­molecular C—H⋯O hydrogen bonds and π–π inter­actions between neighboring phthalimide units. In the crystal structure of 1β (Fig. 3 ▸), the mol­ecules are connected by weak inter­molecular C—H⋯O hydrogen bonds (Table 1 ▸), forming a three-dimensional network. The crystal structure of 1β also features weak π–π inter­actions between two C2–C7 phenyl rings (symmetry code: −x, −y + 1, −z) and between N1/C1/C2/C7/C8 and C11–C16 rings (symmetry codes: −x + , y + , −z +  and −x + , y − , −z + ), with centroid-to-centroid distances of 3.664 (3) and 3.938 (3) Å, respectively.

Figure 3

A partial crystal packing diagram of 1β viewed along the b axis. Dashed lines represent weak inter­molecular C—H⋯O hydrogen bonds. Hydrogen atoms which are not involved in hydrogen bonding are omitted for clarity.

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C3—H3A⋯O3i	0.93	2.43	3.150 (6)	134
C4—H4A⋯O4ii	0.93	2.60	3.300 (5)	133
C15—H15A⋯O2iii	0.93	2.46	3.271 (7)	146

Symmetry codes: (i) ; (ii) ; (iii) .

Hirshfeld surface analysis

The Hirshfeld surface analysis and two-dimensional fingerprint plots were performed using CrystalExplorer version 17.5 (Spackman & Jayatilaka, 2009 ▸; Spackman & McKinnon, 2002 ▸; Turner et al., 2017 ▸). The H⋯O/O⋯H contact is the most populated contact and contributes 38.2 and 34.4% of the total inter­molecular contacts of 1α and 1β (Fig. 4 ▸), respectively. The large red spots on the Hirshfeld surface mapped over d norm for 1β (Fig. 5 ▸) correspond to the inter­molecular C3—H3A⋯O3 and C15—H15A⋯O2 hydrogen-bonds. The tips of the pseudo-mirrored sharp spikes at d e + d i ≃ 2.32 Å represent the shortest H⋯O/O⋯H contacts, corresponding to the inter­molecular C3—H3A⋯O3 hydrogen-bond. The H⋯H contact is the second most populated contact and contributes 25.4 and 26.5% of the total inter­molecular contacts of 1α and 1β, respectively. The shortest H⋯H contacts of 1α (symmetry code: −x, −y, −z + 1) and 1β (symmetry code: −x, y, −z − ) are illustrated as two sharp tips along the diagonal of their two-dimensional fingerprint plots at de ≃ di ≃ 1.06 and 1.21 Å [Fig. 4 ▸(c)], respectively. The percentages of contribution of H⋯C/C⋯H, O⋯C/C⋯O and C⋯C contacts to the Hirshfeld surface are 20.6, 3.3 and 8.9%, respectively, for 1α, and 20.8, 7.9 and 6.7%, respectively, for 1β (Fig. 4 ▸). The absence of significant C—H⋯π inter­actions in the crystal structure of 1β is indicated by the absence of characteristic ‘wings’ in the fingerprint plot of H⋯C/C⋯H contacts [Fig. 4 ▸(d)]. The C⋯C contacts appear as a unique ‘triangle’ focused at d e ≃ d i ≃ 1.75 Å [Fig. 4 ▸(f)]. The inter­molecular π–π inter­actions are illustrated as unique patterns of red and blue ‘triangles’ on the shape-index surface (Fig. 6 ▸), and flat regions on the curvedness surface (Fig. 7 ▸), of the C2–C7, N1/C1/C2/C7/C8 and C11–C16 rings.

Figure 4

The two-dimensional fingerprint plots of 1β for (a) all, (b) H⋯O/O⋯H, (c) H⋯H, (d) H⋯C/C⋯H, (e) O⋯C/C⋯O and (f) C⋯C contacts. d i and d e are the distances from the Hirshfeld surface to the nearest atom inter­ior and exterior, respectively, to the surface.

Figure 5

The Hirshfeld surface mapped over d norm for the mol­ecule in the asymmetric unit of 1β hydrogen-bonded to two neighbouring mol­ecules.

Figure 6

The Hirshfeld surface mapped over shape-index for 1β.

Figure 7

The Hirshfeld surface mapped over curvedness for 1β.

Lattice energy calculation

The C—H bond lengths in 1α and 1β were normalized to 1.08 Å and the lattice energies were calculated by using the CLP-PIXEL software package (Gavezzotti, 2003 ▸, 2008 ▸). The calculated lattice energy of 1α (130.3 kJ mol−1) is slightly larger than for 1β (128.5 kJ mol−1), indicating that 1α is slightly more stable than 1β under ambient conditions.

Synthesis and crystallization

Single crystals of 1β were obtained from an unsuccessful synthesis of 2-{[(3-iodo­pyridin-4-yl)amino]­meth­yl}isoindoline-1,3-dione by reacting N-(bromo­meth­yl)phthalimide (1 mmol) and 4-amino-3-iodo­pyridine (1 mmol) in N,N-di­methyl­formamide (8 ml) with the presence of a catalytic amount of anhydrous potassium carbonate. The reaction solution was stirred for about 2 h at room temperature. Once the reaction was complete, the resultant mixture was poured into a beaker of ice-cooled water to obtain a precipitate (Then et al., 2018 ▸), which was then filtered, washed with distilled water and dried. Crystals suitable for X-ray analysis were obtained by slow evaporation of a methanol solution.

Refinement

Crystal data, data collection and structure refinement details of 1β are summarized in Table 2 ▸. All H atoms were positioned geometrically (C—H = 0.93 and 0.97 Å) and refined using a riding model, with U iso(H) = 1.2U eq(C).

Table 2

Experimental details

Crystal data
Chemical formula	C17H10N2O4
M r	306.27
Crystal system, space group	Monoclinic, C2/c
Temperature (K)	296
a, b, c (Å)	26.296 (5), 7.9996 (15), 16.987 (4)
β (°)	129.165 (10)
V (Å3)	2770.5 (10)
Z	8
Radiation type	Mo Kα
μ (mm−1)	0.11
Crystal size (mm)	0.44 × 0.13 × 0.02
Data collection
Diffractometer	Bruker SMART APEXII DUO CCD area-detector
Absorption correction	Multi-scan (SADABS; Bruker, 2009 ▸)
T min, T max	0.649, 0.745
No. of measured, independent and observed [I > 2σ(I)] reflections	29675, 2444, 1213
R int	0.128
(sin θ/λ)max (Å−1)	0.595
Refinement
R[F 2 > 2σ(F 2)], wR(F 2), S	0.063, 0.158, 1.02
No. of reflections	2444
No. of parameters	208
H-atom treatment	H-atom parameters constrained
Δρmax, Δρmin (e Å−3)	0.14, −0.17

Computer programs: APEX2 and SAINT (Bruker, 2009 ▸), SHELXS2013 and SHELXTL (Sheldrick, 2008 ▸), SHELXL2014 (Sheldrick, 2015 ▸), Mercury (Macrae et al., 2008 ▸), PLATON (Spek, 2009 ▸) and publCIF (Westrip, 2010 ▸).

Crystal structure: contains datablock(s) I. DOI: 10.1107/S2056989018017425/jj2205sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989018017425/jj2205Isup2.hkl

Click here for additional data file.

Supporting information file. DOI: 10.1107/S2056989018017425/jj2205Isup3.cml

CCDC reference: 1884044

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

C17H10N2O4	F(000) = 1264
Mr = 306.27	Dx = 1.469 Mg m−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 26.296 (5) Å	Cell parameters from 1601 reflections
b = 7.9996 (15) Å	θ = 2.4–26.4°
c = 16.987 (4) Å	µ = 0.11 mm−1
β = 129.165 (10)°	T = 296 K
V = 2770.5 (10) Å3	Block, colourless
Z = 8	0.44 × 0.13 × 0.02 mm

Bruker SMART APEXII DUO CCD area-detector diffractometer	2444 independent reflections
Radiation source: fine-focus sealed tube	1213 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.128
φ and ω scans	θmax = 25.0°, θmin = 2.0°
Absorption correction: multi-scan (SADABS; Bruker, 2009)	h = −31→31
Tmin = 0.649, Tmax = 0.745	k = −9→9
29675 measured reflections	l = −20→20

Refinement on F2	0 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.063	H-atom parameters constrained
wR(F2) = 0.158	w = 1/[σ2(Fo2) + (0.0624P)2 + 0.5204P] where P = (Fo2 + 2Fc2)/3
S = 1.02	(Δ/σ)max < 0.001
2444 reflections	Δρmax = 0.14 e Å−3
208 parameters	Δρmin = −0.17 e Å−3

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.

	x	y	z	Uiso*/Ueq
O1	0.05520 (11)	0.9015 (3)	0.12678 (18)	0.0786 (8)
O2	0.20385 (12)	0.6374 (3)	0.11771 (17)	0.0769 (8)
O3	0.32974 (11)	0.7796 (3)	0.34998 (18)	0.0817 (8)
O4	0.15774 (12)	0.6563 (3)	0.34093 (18)	0.0765 (8)
N1	0.14191 (12)	0.7785 (3)	0.14765 (19)	0.0563 (8)
N2	0.23369 (12)	0.7434 (3)	0.32431 (19)	0.0577 (8)
C1	0.07580 (16)	0.8101 (4)	0.0966 (3)	0.0595 (9)
C2	0.04023 (16)	0.7104 (4)	0.0028 (2)	0.0547 (9)
C3	−0.02562 (16)	0.6944 (4)	−0.0726 (2)	0.0620 (10)
H3A	−0.0554	0.7553	−0.0718	0.074*
C4	−0.04608 (18)	0.5854 (5)	−0.1492 (3)	0.0777 (11)
H4A	−0.0908	0.5706	−0.2014	0.093*
C5	−0.0021 (2)	0.4972 (5)	−0.1507 (3)	0.0798 (12)
H5A	−0.0176	0.4222	−0.2033	0.096*
C6	0.06535 (19)	0.5173 (5)	−0.0753 (3)	0.0697 (10)
H6A	0.0955	0.4600	−0.0768	0.084*
C7	0.08469 (15)	0.6259 (4)	0.0011 (2)	0.0531 (9)
C8	0.15090 (17)	0.6749 (4)	0.0923 (2)	0.0568 (9)
C9	0.19381 (15)	0.8576 (5)	0.2405 (2)	0.0671 (10)
H9A	0.1752	0.9399	0.2578	0.081*
H9B	0.2216	0.9165	0.2305	0.081*
C10	0.30011 (17)	0.7197 (5)	0.3748 (3)	0.0625 (10)
C11	0.32396 (17)	0.6090 (4)	0.4617 (2)	0.0591 (9)
C12	0.38561 (19)	0.5506 (5)	0.5381 (3)	0.0765 (11)
H12A	0.4214	0.5788	0.5418	0.092*
C13	0.3923 (2)	0.4479 (6)	0.6095 (3)	0.0930 (14)
H13A	0.4336	0.4071	0.6628	0.112*
C14	0.3398 (3)	0.4050 (5)	0.6036 (3)	0.0956 (14)
H14A	0.3458	0.3341	0.6522	0.115*
C15	0.2779 (2)	0.4654 (5)	0.5263 (3)	0.0784 (11)
H15A	0.2420	0.4371	0.5222	0.094*
C16	0.27123 (18)	0.5674 (4)	0.4564 (3)	0.0607 (9)
C17	0.21289 (18)	0.6552 (4)	0.3696 (3)	0.0590 (9)

	U11	U22	U33	U12	U13	U23
O1	0.0699 (17)	0.0814 (19)	0.0879 (18)	0.0089 (14)	0.0514 (15)	−0.0122 (15)
O2	0.0556 (16)	0.101 (2)	0.0781 (17)	0.0107 (14)	0.0441 (14)	0.0021 (15)
O3	0.0572 (16)	0.107 (2)	0.0841 (18)	−0.0104 (14)	0.0462 (15)	0.0008 (15)
O4	0.0587 (16)	0.094 (2)	0.0815 (17)	−0.0156 (14)	0.0465 (14)	−0.0159 (14)
N1	0.0423 (17)	0.072 (2)	0.0512 (17)	0.0008 (14)	0.0278 (15)	−0.0056 (15)
N2	0.0450 (18)	0.073 (2)	0.0508 (17)	−0.0036 (15)	0.0279 (15)	0.0004 (15)
C1	0.054 (2)	0.064 (3)	0.063 (2)	0.0040 (19)	0.038 (2)	0.003 (2)
C2	0.051 (2)	0.058 (2)	0.056 (2)	−0.0022 (18)	0.0348 (19)	0.0027 (18)
C3	0.049 (2)	0.068 (3)	0.058 (2)	0.0026 (18)	0.029 (2)	0.007 (2)
C4	0.060 (2)	0.093 (3)	0.062 (3)	−0.010 (2)	0.030 (2)	0.003 (2)
C5	0.089 (3)	0.093 (3)	0.063 (3)	−0.020 (3)	0.050 (3)	−0.010 (2)
C6	0.076 (3)	0.082 (3)	0.060 (2)	0.001 (2)	0.047 (2)	−0.002 (2)
C7	0.048 (2)	0.067 (2)	0.048 (2)	0.0001 (18)	0.0316 (18)	0.0034 (18)
C8	0.049 (2)	0.067 (2)	0.059 (2)	0.0068 (19)	0.036 (2)	0.0113 (19)
C9	0.059 (2)	0.072 (3)	0.057 (2)	−0.0047 (19)	0.030 (2)	−0.001 (2)
C10	0.052 (2)	0.075 (3)	0.061 (2)	−0.008 (2)	0.036 (2)	−0.012 (2)
C11	0.054 (2)	0.067 (2)	0.049 (2)	−0.0031 (19)	0.029 (2)	−0.0094 (19)
C12	0.070 (3)	0.080 (3)	0.063 (3)	0.009 (2)	0.034 (2)	−0.008 (2)
C13	0.091 (3)	0.090 (3)	0.063 (3)	0.022 (3)	0.032 (3)	0.003 (2)
C14	0.135 (4)	0.070 (3)	0.077 (3)	0.010 (3)	0.065 (3)	0.001 (2)
C15	0.103 (3)	0.065 (3)	0.075 (3)	−0.010 (2)	0.060 (3)	−0.012 (2)
C16	0.069 (2)	0.057 (2)	0.051 (2)	−0.009 (2)	0.036 (2)	−0.0096 (19)
C17	0.063 (2)	0.059 (2)	0.060 (2)	−0.014 (2)	0.041 (2)	−0.0183 (19)

O1—C1	1.201 (4)	C5—H5A	0.9300
O2—C8	1.207 (3)	C6—C7	1.365 (4)
O3—C10	1.195 (4)	C6—H6A	0.9300
O4—C17	1.203 (4)	C7—C8	1.476 (4)
N1—C8	1.381 (4)	C9—H9A	0.9700
N1—C1	1.391 (4)	C9—H9B	0.9700
N1—C9	1.425 (4)	C10—C11	1.480 (5)
N2—C17	1.386 (4)	C11—C12	1.369 (4)
N2—C10	1.389 (4)	C11—C16	1.372 (4)
N2—C9	1.441 (4)	C12—C13	1.380 (5)
C1—C2	1.473 (4)	C12—H12A	0.9300
C2—C3	1.362 (4)	C13—C14	1.363 (5)
C2—C7	1.366 (4)	C13—H13A	0.9300
C3—C4	1.364 (5)	C14—C15	1.382 (5)
C3—H3A	0.9300	C14—H14A	0.9300
C4—C5	1.369 (5)	C15—C16	1.358 (5)
C4—H4A	0.9300	C15—H15A	0.9300
C5—C6	1.394 (5)	C16—C17	1.470 (5)
C8—N1—C1	111.6 (3)	N1—C9—N2	113.7 (3)
C8—N1—C9	124.3 (3)	N1—C9—H9A	108.8
C1—N1—C9	123.8 (3)	N2—C9—H9A	108.8
C17—N2—C10	111.8 (3)	N1—C9—H9B	108.8
C17—N2—C9	125.1 (3)	N2—C9—H9B	108.8
C10—N2—C9	122.9 (3)	H9A—C9—H9B	107.7
O1—C1—N1	124.6 (3)	O3—C10—N2	125.0 (4)
O1—C1—C2	130.0 (3)	O3—C10—C11	129.2 (3)
N1—C1—C2	105.4 (3)	N2—C10—C11	105.8 (3)
C3—C2—C7	122.1 (3)	C12—C11—C16	121.5 (4)
C3—C2—C1	129.0 (3)	C12—C11—C10	130.7 (4)
C7—C2—C1	108.9 (3)	C16—C11—C10	107.8 (3)
C2—C3—C4	117.3 (3)	C11—C12—C13	117.0 (4)
C2—C3—H3A	121.4	C11—C12—H12A	121.5
C4—C3—H3A	121.4	C13—C12—H12A	121.5
C3—C4—C5	121.3 (3)	C14—C13—C12	121.6 (4)
C3—C4—H4A	119.4	C14—C13—H13A	119.2
C5—C4—H4A	119.4	C12—C13—H13A	119.2
C4—C5—C6	121.5 (4)	C13—C14—C15	120.8 (4)
C4—C5—H5A	119.3	C13—C14—H14A	119.6
C6—C5—H5A	119.3	C15—C14—H14A	119.6
C7—C6—C5	116.2 (3)	C16—C15—C14	117.7 (4)
C7—C6—H6A	121.9	C16—C15—H15A	121.1
C5—C6—H6A	121.9	C14—C15—H15A	121.1
C6—C7—C2	121.6 (3)	C15—C16—C11	121.4 (4)
C6—C7—C8	130.6 (3)	C15—C16—C17	129.8 (4)
C2—C7—C8	107.7 (3)	C11—C16—C17	108.8 (3)
O2—C8—N1	124.1 (3)	O4—C17—N2	124.6 (3)
O2—C8—C7	129.7 (3)	O4—C17—C16	129.6 (4)
N1—C8—C7	106.2 (3)	N2—C17—C16	105.8 (3)
C8—N1—C1—O1	−177.0 (3)	C17—N2—C9—N1	−67.9 (4)
C9—N1—C1—O1	−3.1 (5)	C10—N2—C9—N1	117.6 (3)
C8—N1—C1—C2	2.8 (3)	C17—N2—C10—O3	178.7 (3)
C9—N1—C1—C2	176.7 (3)	C9—N2—C10—O3	−6.2 (5)
O1—C1—C2—C3	−1.7 (6)	C17—N2—C10—C11	−1.4 (3)
N1—C1—C2—C3	178.5 (3)	C9—N2—C10—C11	173.8 (3)
O1—C1—C2—C7	179.8 (4)	O3—C10—C11—C12	2.6 (6)
N1—C1—C2—C7	0.0 (3)	N2—C10—C11—C12	−177.4 (3)
C7—C2—C3—C4	2.1 (5)	O3—C10—C11—C16	−177.6 (4)
C1—C2—C3—C4	−176.2 (3)	N2—C10—C11—C16	2.5 (4)
C2—C3—C4—C5	−0.7 (5)	C16—C11—C12—C13	0.0 (5)
C3—C4—C5—C6	−1.2 (6)	C10—C11—C12—C13	179.8 (3)
C4—C5—C6—C7	1.7 (5)	C11—C12—C13—C14	0.7 (6)
C5—C6—C7—C2	−0.3 (5)	C12—C13—C14—C15	−1.0 (6)
C5—C6—C7—C8	179.1 (3)	C13—C14—C15—C16	0.5 (6)
C3—C2—C7—C6	−1.6 (5)	C14—C15—C16—C11	0.3 (5)
C1—C2—C7—C6	177.0 (3)	C14—C15—C16—C17	−177.0 (3)
C3—C2—C7—C8	178.8 (3)	C12—C11—C16—C15	−0.6 (5)
C1—C2—C7—C8	−2.5 (3)	C10—C11—C16—C15	179.6 (3)
C1—N1—C8—O2	175.4 (3)	C12—C11—C16—C17	177.2 (3)
C9—N1—C8—O2	1.5 (5)	C10—C11—C16—C17	−2.6 (4)
C1—N1—C8—C7	−4.3 (3)	C10—N2—C17—O4	179.2 (3)
C9—N1—C8—C7	−178.1 (3)	C9—N2—C17—O4	4.2 (5)
C6—C7—C8—O2	5.1 (6)	C10—N2—C17—C16	−0.2 (3)
C2—C7—C8—O2	−175.5 (3)	C9—N2—C17—C16	−175.2 (3)
C6—C7—C8—N1	−175.3 (3)	C15—C16—C17—O4	0.0 (6)
C2—C7—C8—N1	4.1 (3)	C11—C16—C17—O4	−177.6 (3)
C8—N1—C9—N2	−69.4 (4)	C15—C16—C17—N2	179.3 (3)
C1—N1—C9—N2	117.4 (3)	C11—C16—C17—N2	1.8 (4)

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3A···O3i	0.93	2.43	3.150 (6)	134
C4—H4A···O4ii	0.93	2.60	3.300 (5)	133
C15—H15A···O2iii	0.93	2.46	3.271 (7)	146