Crystal structure of 3,14-dimethyl-2,13-di­aza-6,17-diazo­niatri­cyclo­[16.4.0.0^7,12]docosane bis­(per­chlorate) from synchrotron X-ray data

In the title salt, C₂₀H₄₂N₄ ²⁺·2ClO₄ ⁻, the macrocyclic dication lies about an inversion center. In the crystal, the organic dication and perchlorate anions are linked through N—H⋯O, C—H⋯O and N—H⋯N hydrogen bonds, forming a three-dimensional network.

Abstract

The crystal structure of the title salt, C₂₀H₄₂N₄ ²⁺·2ClO₄ ⁻, has been determined using synchrotron radiation at 220 (2) K. The structure determination reveals that protonation has occurred at diagonally opposite amine N atoms. The asymmetric unit comprises one half of the organic dication, which lies about a center of inversion, and one perchlorate anion. The macrocyclic dication adopts the most stable endodentate trans-III conformation. The crystal structure is stabilized by intra­molecular N—H⋯N, and inter­molecular N—H⋯O and C–H⋯O hydrogen bonds involving the macrocycle N—H and C—H groups as donors and the O atoms of perchlorate anions as acceptors, giving rise to a three-dimensional network.

Chemical context  

The macrocyclic compound, 3,14-dimethyl-2,6,13,17-tetra­aza­tri­cyclo­(16.4.0.0^7,12)docosane (C₂₀H₄₀N₄) contains a cyclam backbone with two cyclo­hexane subunits and two methyl groups are also attached to carbon atoms 3 and 14 of the propyl chains that bridge opposite pairs of N atoms in the structure. The macrocycle is basic and readily captures two or four protons to form the [C₂₀H₄₂N₄]²⁺ dication or the [C₂₀H₄₄N₄]⁴⁺ tetra­cation in which all of the N—H bonds are generally available for hydrogen-bond formation (Moon et al., 2021 ▸).

Previously, the crystal structures of [Cu(C₂₀H₄₀N₄)](NO₃)₂·3H₂O, [Cu(C₂₀H₄₀N₄)](NO₃)₂, [Cu(C₂₀H₄₀N₄)](ClO₄)₂ and [Cu(C₂₀H₄₀N₄)(H₂O)₂](BF₄)₂·2H₂O were reported together with [Zn(C₂₀H₄₀N₄)(OCOCH₃)₂]. In these structures, the copper(II) or zinc(II) cations have tetra­gonally distorted octa­hedral environments with the four N atoms of the macrocyclic ligand in equatorial positions and the O atoms of the counter-anions, water mol­ecules or acetato ligands in axial positions (Choi et al., 2006 ▸, 2007 ▸, 2012a ▸,b ▸; Ross et al., 2012 ▸). In these Cu^II and Zn^II complexes, the macrocyclic ligands adopt their most stable trans-III configurations. The crystal structures of (C₂₀H₄₀N₄)·2(C₁₁H₁₀O) (Choi et al., 2012c ▸), (C₂₀H₄₀N₄)·2(NO₂OH) (Moon et al., 2020 ▸), [C₂₀H₄₂N₄](SO₄)·2MeOH (White et al., 2015 ▸), [C₂₀H₄₂N₄]Br₂·2H₂O (Moon et al., 2021 ▸) and [C₂₀H₄₄N₄]Br₄·4H₂O (Moon et al., 2021 ▸) have also been determined.

We report here the preparation of a new dicationic compound, [C₂₀H₄₂N₄](ClO₄)₂, (I) and its structural characterization by synchrotron single-crystal X-ray diffraction.

Structural commentary  

An ellipsoid plot of the mol­ecular components in (I) with the atom-numbering scheme is shown in Fig. 1 ▸. The asymmetric unit consists of one half of the macrocyclic dication, which lies about a center of inversion, and one perchlorate anion. The four N atoms are coplanar, and the two methyl substituents are anti with respect to the macrocyclic plane as a result of the mol­ecular inversion symmetry. The [C₂₀H₄₂N₄]²⁺ dication adopts an endodentate conformation and trans-III configuration along the center of the macrocyclic cavity. The endo conformation of the dication may be due to the intra­molecular N—H⋯N hydrogen-bonding inter­action. Within the centrosymmetric diprotonated amine unit, the C—C and N—C bond lengths range from 1.5173 (18) to 1.5368 (18) Å and from 1.4795 (16) to 1.5044 (16) Å, respectively. The range of N—C—C and C—N—C angles is 108.89 (11) to 113.50 (11)° and 113.46 (11) to 114.61 (11)°, respectively. The bond lengths and angles within the dication are comparable to those found in the free ligand or other cations in (C₂₀H₄₀N₄)·2C₁₁H₁₀O (Choi et al., 2012c ▸), [C₂₀H₄₂N₄](SO₄)·2MeOH (White et al., 2015 ▸) and [C₂₀H₄₂N₄][Fe{HB(pz)₃}(CN)₃]₂·2H₂O·2MeOH (Kim et al., 2004 ▸; pz = pyrazol­yl). The protonation of the N atoms may depend on the location of the neighboring counter-anions involved in hydrogen bonding. The bond-length difference can be noticed for several N—C bonds. The N—C bond length involving the non-protonated N1 atom is shorter than that involving protonated N2 atom, e.g. N1—C2 [1.4817 (18) Å] and N1—C3 [1.4795 (16) Å] are slightly shorter than N2—C8 [1.5044 (16) Å] and N2—C9 [1.4952 (18) Å]. Each of the two hydrogen atoms of N2 and N2′ (−x + 1, −y + 2, −z + 1) is involved in hydrogen bonding with both of the two remaining nitro­gen atoms (Table 1 ▸). The intra­molecular hydrogen bonding plays a substantial role in maintaining the endodentate geometry of the diprotonated macrocyclic cation. The Cl—O bond distances in the tetra­hedral ClO₄ ⁻ anion vary from 1.4218 (19) to 1.4529 (16) Å, and the O—Cl—O angles vary from 106.45 (10) to 110.51 (12)°. The distorted geometry of the ClO₄ ⁻ anion undoubtedly results from its involvement in hydrogen-bonding inter­actions with the organic cation.

Figure 1.

The mol­ecular structure of compound (I), drawn with displacement ellipsoids at the 50% probability level. Dashed lines represent hydrogen-bonding inter­actions and primed atoms are related by the symmetry operation (−x + 1, −y + 2, −z + 1).

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1N1⋯O3i	0.86 (2)	2.22 (2)	3.007 (2)	152.4 (18)
N2—H2A⋯O1	0.90	2.09	2.970 (2)	164
N2—H2A⋯O2	0.90	2.56	3.239 (2)	132
N2—H2B⋯N1ii	0.90	2.29	2.9846 (16)	134
N2—H2B⋯N1	0.90	2.39	2.8230 (17)	109
C7—H7A⋯O2iii	0.98	2.57	3.423 (3)	145

Symmetry codes: (i) x, y+1, z; (ii) -x+1, -y+2, -z+1; (iii) -x+{\script{3\over 2}}, y+{\script{1\over 2}}, -z+{\script{3\over 2}}.

Supra­molecular features  

Three N—H⋯O, C–H⋯O and N—H⋯N hydrogen-bonding inter­actions occur in the crystal structure (Table 1 ▸). The O atoms of the perchlorate anions serve as hydrogen-bond acceptors. The ClO₄ ⁻ anions are connected to the [C₂₀H₄₂N₄]²⁺ dication by N—H⋯O hydrogen bonds. The macrocyclic dication is linked to a neighboring ClO₄ ⁻ anion through a very weak C—H⋯O hydrogen bond. The extensive array of these contacts generates a three-dimensional network structure (Fig. 2 ▸), and these hydrogen-bonding inter­actions help to stabilize the crystal structure.

Figure 2.

Crystal packing in compound (I), viewed perpendicular to the ac plane. Dashed lines represent N—H⋯O (cyan), N—H⋯N (blue) and C—H⋯O (purple) hydrogen-bonding inter­actions, respectively.

Database survey  

A search of the Cambridge Structural (Version 5.42, Update 1, February 2021; Groom et al., 2016 ▸) indicated 121 hits for organic and transition-metal compounds containing the macrocycles (C₂₀H₄₀N₄), [C₂₀H₄₂N₄]²⁺ or [C₂₀H₄₄N₄]⁴⁺. The crystal structures of (C₂₀H₄₀N₄)·2C₁₁H₁₀O (Choi et al., 2012c ▸), [C₂₀H₄₂N₄](SO₄)·2MeOH (White et al., 2015 ▸), [C₂₀H₄₂N₄]Br₂·2H₂O (Moon et al., 2021 ▸), [C₂₀H₄₄N₄]Cl₄·4H₂O (Moon et al., 2018 ▸) and [C₂₀H₄₄N₄]Br₄·4H₂O (Moon et al., 2021 ▸) were reported previously and commented on in the Chemical context section.

Synthesis and crystallization  

Commercially available trans-1,2-cyclo­hexa­nedi­amine and methyl vinyl ketone (Sigma-Aldrich) were used as provided. All chemicals were reagent grade and used without further purification. As a starting material, macrocycle 3,14-dimethyl-2,6,13,17-tetra­aza­tri­cyclo­(16.4.0.0^7,12)docosane, L, was prepared according to a published procedure (Kang et al., 1991 ▸). Macrocycle L (0.034 g, 0.1 mmol) was suspended in methanol (20 mL) and the pH was adjusted to 3.0 with 0.5 M HClO₄. The mixture was stirred magnetically for 30 min and the resulting solution was filtered. The neat filtrate was allowed to stand for one week to give block-like colorless crystals of (I) suitable for X-ray structural analysis.

Refinement  

Crystal data, data collection and structure refinement details are summarized in Table 2 ▸. All non-hydrogen atoms were refined anisotropically. All C-bound H atoms and the hydrogen atoms of the diprotonated amine (H2A and H2B) were placed in geometrically idealized positions and constrained to ride on their parent atoms, with C—H distances of 0.97–0.98 Å and an N—H distance of 0.99 Å, and with U _iso(H) values of 1.5 and 1.2 times, respectively, that of the parent atoms. The one N-bound H atom (H1N1) of the amine was assigned based on a difference-Fourier map, and a U _iso(H) value of 1.5U _eq(N1).

Table 2. Experimental details.

Crystal data
Chemical formula	C20H42N4 2+·2ClO4 −
M r	537.47
Crystal system, space group	Monoclinic, P21/n
Temperature (K)	220
a, b, c (Å)	10.689 (2), 8.4450 (17), 14.020 (3)
β (°)	92.90 (3)
V (Å3)	1263.9 (4)
Z	2
Radiation type	Synchrotron, λ = 0.630 Å
μ (mm−1)	0.22
Crystal size (mm)	0.08 × 0.08 × 0.08
Data collection
Diffractometer	Rayonix MX225HS CCD area detector
Absorption correction	Empirical (using intensity measurements) (HKL3000sm SCALEPACK; Otwinowski et al., 2003 ▸)
T min, T max	0.957, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections	12842, 3549, 3164
R int	0.063
(sin θ/λ)max (Å−1)	0.696
Refinement
R[F 2 > 2σ(F 2)], wR(F 2), S	0.055, 0.172, 1.11
No. of reflections	3549
No. of parameters	158
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å−3)	0.86, −0.44

Computer programs: PAL BL2D-SMDC (Shin et al., 2016 ▸), HKL3000sm (Otwinowski & Minor, 1997 ▸), SHELXT2018 (Sheldrick, 2015a ▸), SHELXL2018 (Sheldrick, 2015b ▸), DIAMOND 4 (Putz & Brandenburg, 2014 ▸) and publCIF (Westrip, 2010 ▸).

Supplementary Material

CCDC reference: 2079010

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

supplementary crystallographic information

Crystal data

C20H42N42+·2ClO4−	F(000) = 576
Mr = 537.47	Dx = 1.412 Mg m−3
Monoclinic, P21/n	Synchrotron radiation, λ = 0.630 Å
a = 10.689 (2) Å	Cell parameters from 41946 reflections
b = 8.4450 (17) Å	θ = 0.4–33.6°
c = 14.020 (3) Å	µ = 0.22 mm−1
β = 92.90 (3)°	T = 220 K
V = 1263.9 (4) Å3	Block, colorless
Z = 2	0.08 × 0.08 × 0.08 mm

Data collection

Rayonix MX225HS CCD area detector diffractometer	3164 reflections with I > 2σ(I)
Radiation source: PLSII 2D bending magnet	Rint = 0.063
ω scan	θmax = 26.0°, θmin = 2.5°
Absorption correction: empirical (using intensity measurements) (HKL3000sm Scalepack; Otwinowski et al., 2003)	h = −14→14
Tmin = 0.957, Tmax = 1.000	k = −11→11
12842 measured reflections	l = −19→19
3549 independent reflections

Refinement

Refinement on F2	0 restraints
Least-squares matrix: full	Hydrogen site location: mixed
R[F2 > 2σ(F2)] = 0.055	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.172	w = 1/[σ2(Fo2) + (0.1016P)2 + 0.4023P] where P = (Fo2 + 2Fc2)/3
S = 1.11	(Δ/σ)max < 0.001
3549 reflections	Δρmax = 0.86 e Å−3
158 parameters	Δρmin = −0.44 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
N1	0.35546 (11)	1.04262 (14)	0.58019 (8)	0.0179 (2)
H1N1	0.3881 (18)	1.135 (3)	0.5913 (14)	0.027*
N2	0.58037 (10)	0.87373 (14)	0.61832 (7)	0.0189 (2)
H2A	0.556980	0.771653	0.612584	0.023*
H2B	0.556374	0.923391	0.563613	0.023*
C1	0.17869 (17)	0.8824 (2)	0.51236 (13)	0.0357 (4)
H1A	0.104402	0.890989	0.470004	0.054*
H1B	0.158772	0.823502	0.569045	0.054*
H1C	0.243896	0.827482	0.479816	0.054*
C2	0.22417 (13)	1.04715 (17)	0.54095 (10)	0.0208 (3)
H2	0.171026	1.086474	0.591704	0.025*
C3	0.37355 (13)	0.95865 (16)	0.67248 (9)	0.0186 (3)
H3	0.339745	0.850008	0.664720	0.022*
C4	0.30834 (15)	1.03951 (18)	0.75469 (10)	0.0254 (3)
H4A	0.337406	1.149317	0.760396	0.030*
H4B	0.217795	1.041505	0.739748	0.030*
C5	0.33416 (16)	0.95505 (19)	0.85002 (10)	0.0270 (3)
H5A	0.296287	1.015186	0.900932	0.032*
H5B	0.295502	0.849816	0.847313	0.032*
C6	0.47429 (16)	0.9383 (2)	0.87300 (10)	0.0284 (3)
H6A	0.488076	0.877269	0.932053	0.034*
H6B	0.511244	1.043474	0.883362	0.034*
C7	0.53896 (14)	0.85522 (19)	0.79198 (9)	0.0258 (3)
H7A	0.629365	0.849658	0.807106	0.031*
H7B	0.506976	0.746930	0.784522	0.031*
C8	0.51363 (13)	0.94746 (16)	0.69916 (9)	0.0187 (3)
H8	0.546260	1.056300	0.708844	0.022*
C9	0.71994 (13)	0.8814 (2)	0.63136 (9)	0.0257 (3)
H9A	0.747588	0.810782	0.683724	0.031*
H9B	0.744648	0.989510	0.649456	0.031*
C10	0.78531 (13)	0.83475 (19)	0.54199 (9)	0.0239 (3)
H10A	0.750585	0.733364	0.519265	0.029*
H10B	0.874193	0.817560	0.559494	0.029*
Cl1	0.54918 (4)	0.43816 (5)	0.65415 (3)	0.03296 (16)
O1	0.45977 (15)	0.55690 (19)	0.61926 (13)	0.0495 (4)
O2	0.67029 (15)	0.5118 (2)	0.65563 (14)	0.0618 (5)
O3	0.5462 (2)	0.3046 (2)	0.59233 (17)	0.0762 (6)
O4	0.51936 (16)	0.3923 (2)	0.74864 (12)	0.0598 (5)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
N1	0.0238 (5)	0.0176 (5)	0.0127 (5)	−0.0015 (4)	0.0047 (4)	0.0024 (4)
N2	0.0246 (5)	0.0218 (6)	0.0109 (4)	0.0014 (4)	0.0056 (4)	0.0023 (4)
C1	0.0388 (8)	0.0307 (8)	0.0374 (9)	−0.0110 (7)	−0.0011 (6)	−0.0010 (7)
C2	0.0229 (6)	0.0235 (7)	0.0165 (6)	0.0007 (5)	0.0065 (4)	0.0003 (5)
C3	0.0262 (6)	0.0175 (6)	0.0128 (5)	0.0000 (5)	0.0073 (4)	0.0028 (4)
C4	0.0347 (7)	0.0271 (7)	0.0155 (6)	0.0061 (6)	0.0121 (5)	0.0040 (5)
C5	0.0407 (8)	0.0275 (7)	0.0139 (6)	0.0017 (6)	0.0128 (5)	0.0031 (5)
C6	0.0427 (8)	0.0326 (8)	0.0105 (6)	−0.0001 (6)	0.0061 (5)	0.0000 (5)
C7	0.0349 (7)	0.0315 (7)	0.0113 (5)	0.0049 (6)	0.0060 (5)	0.0046 (5)
C8	0.0265 (6)	0.0194 (6)	0.0106 (5)	−0.0004 (5)	0.0063 (4)	0.0006 (4)
C9	0.0242 (6)	0.0387 (8)	0.0146 (6)	0.0006 (6)	0.0047 (4)	0.0006 (5)
C10	0.0264 (6)	0.0291 (7)	0.0168 (6)	0.0062 (5)	0.0063 (5)	0.0030 (5)
Cl1	0.0328 (2)	0.0270 (3)	0.0393 (3)	−0.00471 (14)	0.00435 (17)	0.00776 (14)
O1	0.0454 (8)	0.0462 (9)	0.0564 (9)	0.0068 (6)	−0.0015 (7)	0.0120 (7)
O2	0.0423 (8)	0.0658 (11)	0.0770 (12)	−0.0215 (8)	0.0003 (8)	0.0287 (10)
O3	0.1111 (16)	0.0318 (8)	0.0893 (14)	−0.0193 (10)	0.0399 (12)	−0.0118 (9)
O4	0.0577 (9)	0.0755 (12)	0.0463 (9)	−0.0126 (9)	0.0036 (7)	0.0284 (9)

Geometric parameters (Å, º)

N1—C3	1.4795 (16)	C5—C6	1.523 (2)
N1—C2	1.4817 (18)	C5—H5A	0.9800
N1—H1N1	0.86 (2)	C5—H5B	0.9800
N2—C9	1.4952 (18)	C6—C7	1.530 (2)
N2—C8	1.5044 (16)	C6—H6A	0.9800
N2—H2A	0.9000	C6—H6B	0.9800
N2—H2B	0.9000	C7—C8	1.5290 (18)
C1—C2	1.521 (2)	C7—H7A	0.9800
C1—H1A	0.9700	C7—H7B	0.9800
C1—H1B	0.9700	C8—H8	0.9900
C1—H1C	0.9700	C9—C10	1.5173 (18)
C2—C10i	1.5314 (19)	C9—H9A	0.9800
C2—H2	0.9900	C9—H9B	0.9800
C3—C8	1.5278 (19)	C10—H10A	0.9800
C3—C4	1.5368 (18)	C10—H10B	0.9800
C3—H3	0.9900	Cl1—O3	1.4218 (19)
C4—C5	1.528 (2)	Cl1—O4	1.4315 (16)
C4—H4A	0.9800	Cl1—O2	1.4354 (15)
C4—H4B	0.9800	Cl1—O1	1.4529 (16)
C3—N1—C2	114.61 (11)	H5A—C5—H5B	108.0
C3—N1—H1N1	103.8 (13)	C5—C6—C7	111.23 (13)
C2—N1—H1N1	114.3 (13)	C5—C6—H6A	109.4
C9—N2—C8	113.46 (11)	C7—C6—H6A	109.4
C9—N2—H2A	108.9	C5—C6—H6B	109.4
C8—N2—H2A	108.9	C7—C6—H6B	109.4
C9—N2—H2B	108.9	H6A—C6—H6B	108.0
C8—N2—H2B	108.9	C8—C7—C6	109.34 (13)
H2A—N2—H2B	107.7	C8—C7—H7A	109.8
C2—C1—H1A	109.5	C6—C7—H7A	109.8
C2—C1—H1B	109.5	C8—C7—H7B	109.8
H1A—C1—H1B	109.5	C6—C7—H7B	109.8
C2—C1—H1C	109.5	H7A—C7—H7B	108.3
H1A—C1—H1C	109.5	N2—C8—C3	109.71 (11)
H1B—C1—H1C	109.5	N2—C8—C7	111.10 (11)
N1—C2—C1	110.99 (12)	C3—C8—C7	111.66 (11)
N1—C2—C10i	108.89 (11)	N2—C8—H8	108.1
C1—C2—C10i	112.81 (13)	C3—C8—H8	108.1
N1—C2—H2	108.0	C7—C8—H8	108.1
C1—C2—H2	108.0	N2—C9—C10	112.70 (11)
C10i—C2—H2	108.0	N2—C9—H9A	109.1
N1—C3—C8	109.08 (10)	C10—C9—H9A	109.1
N1—C3—C4	113.50 (11)	N2—C9—H9B	109.1
C8—C3—C4	108.65 (12)	C10—C9—H9B	109.1
N1—C3—H3	108.5	H9A—C9—H9B	107.8
C8—C3—H3	108.5	C9—C10—C2i	116.25 (13)
C4—C3—H3	108.5	C9—C10—H10A	108.2
C5—C4—C3	112.33 (12)	C2i—C10—H10A	108.2
C5—C4—H4A	109.1	C9—C10—H10B	108.2
C3—C4—H4A	109.1	C2i—C10—H10B	108.2
C5—C4—H4B	109.1	H10A—C10—H10B	107.4
C3—C4—H4B	109.1	O3—Cl1—O4	110.51 (12)
H4A—C4—H4B	107.9	O3—Cl1—O2	110.20 (14)
C6—C5—C4	111.15 (12)	O4—Cl1—O2	110.28 (11)
C6—C5—H5A	109.4	O3—Cl1—O1	110.37 (13)
C4—C5—H5A	109.4	O4—Cl1—O1	108.95 (11)
C6—C5—H5B	109.4	O2—Cl1—O1	106.45 (10)
C4—C5—H5B	109.4
C3—N1—C2—C1	−67.02 (15)	C9—N2—C8—C7	−65.28 (15)
C3—N1—C2—C10i	168.21 (11)	N1—C3—C8—N2	−53.86 (14)
C2—N1—C3—C8	173.99 (10)	C4—C3—C8—N2	−178.05 (10)
C2—N1—C3—C4	−64.72 (15)	N1—C3—C8—C7	−177.48 (11)
N1—C3—C4—C5	−177.06 (12)	C4—C3—C8—C7	58.32 (15)
C8—C3—C4—C5	−55.52 (16)	C6—C7—C8—N2	177.49 (12)
C3—C4—C5—C6	54.72 (17)	C6—C7—C8—C3	−59.68 (16)
C4—C5—C6—C7	−55.07 (17)	C8—N2—C9—C10	−169.40 (12)
C5—C6—C7—C8	57.14 (16)	N2—C9—C10—C2i	71.50 (17)
C9—N2—C8—C3	170.77 (11)

Symmetry code: (i) −x+1, −y+2, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N1···O3ii	0.86 (2)	2.22 (2)	3.007 (2)	152.4 (18)
N2—H2A···O1	0.90	2.09	2.970 (2)	164
N2—H2A···O2	0.90	2.56	3.239 (2)	132
N2—H2B···N1i	0.90	2.29	2.9846 (16)	134
N2—H2B···N1	0.90	2.39	2.8230 (17)	109
C7—H7A···O2iii	0.98	2.57	3.423 (3)	145

Symmetry codes: (i) −x+1, −y+2, −z+1; (ii) x, y+1, z; (iii) −x+3/2, y+1/2, −z+3/2.