Bis(4-methyl­benzyl­ammonium) tetra­bromido­zincate

Aarthi, R.; Thiruvalluvar, A.A.; Ramachandra Raja, C.

doi:10.1107/S241431461800648X

metal-organic compounds

IUCrDATA

ISSN: 2414-3146

Volume 3| Part 5| May 2018| x180648

https://doi.org/10.1107/S241431461800648X

Open

access

Bis(4-methylbenzylammonium) tetrabromidozincate

Ramkumar Aarthi,^a Aravazhi Amalan Thiruvalluvar ^b ^* and Chidambaram Ramachandra Raja ^a

^aDepartment of Physics, Government Arts College (Autonomous), Kumbakonam 612 002, Tamilnadu, India, and ^bPrincipal, Kunthavai Naacchiyaar Government Arts College for Women (Autonomous), Thanjavur 613 007, Tamilnadu, India
^*Correspondence e-mail: thiruvalluvar.a@gmail.com

Edited by M. Weil, Vienna University of Technology, Austria (Received 19 April 2018; accepted 26 April 2018; online 1 May 2018)

The structure of the non-centrosymmetric organic–inorganic hybrid material, (C₈H₁₂N)₂[ZnBr₄], consists of two 4-methylbenzylammonium cations and one [ZnBr₄]²⁻ anion connected by N—H⋯Br and C—H⋯Br hydrogen bonds. The Zn^II cation has a slightly distorted tetrahedral coordination environment. No π–π stacking interactions between the phenylene rings but C—H⋯π interactions towards them are observed. The structure was refined as a two-component inversion twin.

Keywords: crystal structure; non-centrosymmetric organic-inorganic hybrid material; C—H⋯Br and N—H⋯Br hydrogen bondings; C—H⋯π interactions.

CCDC reference: 1839864

Structure description

Non-linear optical (NLO) materials play a vital role in the field of photonics as they generate coherent radiation at new frequencies that are not available with conventional laser sources. Organic crystals with non-linear optical properties frequently have poor mechanical and thermal properties due to the presence of weak van der Waals interactions and hydrogen bonds (Dolbecq et al., 2010 ), whereas inorganic crystals possess good mechanical and thermal properties but have low NLO properties due to the presence of strong covalent or ionic interactions (Jiang & Fang, 1999 ). Hence, attempts have been made by several groups to synthesize new organic–inorganic materials with NLO properties, combining the features of both organic and inorganic crystals. In this context we report here the synthesis and crystal structure of a new organic–inorganic hybrid compound, bis(4-methylbenzylammonium) tetrabromidozincate. This salt crystallizes in the non-centrosymmetric space group type Pna2₁, and hence could be a potential candidate for second order non-linear optical properties.

The asymmetric unit of the title compound consists of an isolated tetrabromidozincate anion, [ZnBr₄]²⁻, and two 4-methylbenzylammonium cations, (C₈H₁₂N)⁺, as shown in Fig. 1. The Zn²⁺ cation is tetrahedrally coordinated by four bromide ligands with Zn—Br bond lengths ranging from 2.399 (3) to 2.426 (3) Å, and Br—Zn—Br bond angles varying between 104.90 (12) and 113.82 (13)°.

Figure 1
A view of the asymmetric unit, showing the atom numbering and displacement ellipsoids drawn at the 30% probability level. Dashed lines indicate hydrogen-bonding interactions.

The crystal structure consists of layers of 4-methylbenzylammonium cations sandwiched between tetrabromidozincate layers extending parallel to the ac plane, as shown in Fig. 2. The cationic units are linked into a two-dimensional network by two weak C—H⋯π interactions (Fig. 3, Table 1). The crystal packing is assured by a complex hydrogen-bonding system, involving the positively charged ammonium groups and to a lesser extent the methylene groups of the cations as donors and the bromide ligands of the isolated tetrahedral [ZnBr₄]²⁻ units as acceptors (Table 1), which reinforce the Coulombic interactions, as depicted in Fig. 2.

Table 1
Hydrogen-bond geometry (Å, °)

Cg1 and Cg2 are the centroids of the C1–C6 and C9–C14 benzene rings, respectively.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C2—H2⋯Cg2ⁱ	0.93	2.94	3.73 (3)	143
C14—H14⋯Cg1ⁱⁱ	0.93	2.94	3.72 (2)	143
C8—H8B⋯Br3ⁱⁱⁱ	0.97	2.88	3.81 (2)	161
C8—H8A⋯Br1^iv	0.97	2.91	3.82 (3)	157
C16—H16B⋯Br4^v	0.97	3.03	3.90 (3)	150
N1—H1A⋯Br1^vi	0.89	2.58	3.427 (17)	159
N1—H1B⋯Br2^iv	0.89	2.92	3.626 (17)	137
N1—H1B⋯Br4^vi	0.89	2.94	3.613 (16)	133
N1—H1C⋯Br2^vii	0.89	2.96	3.414 (17)	113
N1—H1C⋯Br4^vii	0.89	2.82	3.563 (17)	142
N2—H2A⋯Br2	0.89	2.61	3.46 (2)	159
N2—H2B⋯Br3^viii	0.89	2.47	3.34 (2)	166
N2—H2C⋯Br3	0.89	2.79	3.45 (3)	132
Symmetry codes: (i) x, y, z-1; (ii) $[x-{\script{1\over 2}}, -y+{\script{1\over 2}}, z+1]$ ; (iii) $[x+{\script{1\over 2}}, -y+{\script{1\over 2}}, z]$ ; (iv) $[-x+{\script{3\over 2}}, y-{\script{1\over 2}}, z-{\script{1\over 2}}]$ ; (v) x, y, z+1; (vi) $[-x+{\script{3\over 2}}, y-{\script{1\over 2}}, z+{\script{1\over 2}}]$ ; (vii) $[x-{\script{1\over 2}}, -y+{\script{1\over 2}}, z]$ ; (viii) $[-x+1, -y+1, z+{\script{1\over 2}}]$ .

Figure 2
Packing diagram of the title compound viewed along the c axis, showing the alternate stacking, along the b axis, of organic and inorganic layers. Dashed lines indicate the hydrogen-bonding network.

Figure 3
Partial packing diagram showing the C2—H2⋯π interaction involving the C9–C14 benzene ring and C14—H14⋯π interaction involving the C1–C6 benzene ring.

Synthesis and crystallization

Bis(4-methylbenzylammonium) tetrabromidozincate single crystals were obtained by the solution growth solvent evaporation method. A mixture of 4-methylbenzylamine (2 mmol, 2.73 ml), zinc bromide (1 mmol, 1.125 g) and HBr (2 mmol, 2.73 ml) in water (20 ml) was well stirred using a magnetic stirrer for 3 h and left to stand at room temperature. After 15 d, colourless single crystals of the title compound were harvested.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2. The refinement was finalized under consideration of inversion twinning.

Table 2
Experimental details

Crystal data
Chemical formula	(C₈H₁₂N)₂[ZnBr₄]
M_r	629.38
Crystal system, space group	Orthorhombic, Pna2₁
Temperature (K)	296
a, b, c (Å)	11.0702 (5), 26.0585 (13), 7.7302 (3)
V (Å³)	2229.95 (17)
Z	4
Radiation type	Mo Kα
μ (mm⁻¹)	8.27
Crystal size (mm)	0.15 × 0.15 × 0.10

Data collection
Diffractometer	Bruker Kappa APEX3 CMOS
Absorption correction	Multi-scan (SADABS; Bruker, 2016 )
T_min, T_max	0.309, 0.746
No. of measured, independent and observed [I > 2σ(I)] reflections	27881, 3809, 3481
R_int	0.056
(sin θ/λ)_max (Å⁻¹)	0.595

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.074, 0.156, 1.36
No. of reflections	3809
No. of parameters	213
No. of restraints	1
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	1.40, −1.01
Absolute structure	Refined as an inversion twin
Absolute structure parameter	0.18 (6)
Computer programs: APEX3 and SAINT (Bruker, 2016), SHELXT2018 (Sheldrick, 2015a ), SHELXL2018 (Sheldrick, 2015b ), ORTEP-3 for Windows (Farrugia, 2012 ), PLATON (Spek, 2009 ), Mercury (Macrae et al., 2008 ) and publCIF (Westrip, 2010 ).

Structural data

CCDC reference: 1839864

Crystal structure: contains datablock I. DOI: https://doi.org/10.1107/S241431461800648X/wm4078sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S241431461800648X/wm4078Isup2.hkl

Supporting information file. DOI: https://doi.org/10.1107/S241431461800648X/wm4078Isup3.cdx

checkCIF report

Computing details top

Data collection: APEX3 (Bruker, 2016); cell refinement: SAINT (Bruker, 2016); data reduction: SAINT (Bruker, 2016); program(s) used to solve structure: SHELXT2018 (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2018 (Sheldrick, 2015b); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012), PLATON (Spek, 2009) and Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXL2018 (Sheldrick, 2015b), PLATON (Spek, 2009) and publCIF (Westrip, 2010).

Bis(4-methylbenzylammonium) tetrabromidozincate top

Crystal data top

(C₈H₁₂N)₂[ZnBr₄]	D_x = 1.875 Mg m⁻³
M_r = 629.38	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pna2₁	Cell parameters from 9620 reflections
a = 11.0702 (5) Å	θ = 3.0–27.9°
b = 26.0585 (13) Å	µ = 8.27 mm⁻¹
c = 7.7302 (3) Å	T = 296 K
V = 2229.95 (17) Å³	Block, colourless
Z = 4	0.15 × 0.15 × 0.10 mm
F(000) = 1216

Data collection top

Bruker Kappa APEX3 CMOS diffractometer	3809 independent reflections
Radiation source: fine-focus sealed tube	3481 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.056
ω and φ scan	θ_max = 25.0°, θ_min = 3.0°
Absorption correction: multi-scan (SADABS; Bruker, 2016)	h = −13→13
T_min = 0.309, T_max = 0.746	k = −30→30
27881 measured reflections	l = −9→9

Refinement top

Refinement on F²	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F² > 2σ(F²)] = 0.074	w = 1/[σ²(F_o²) + 30.013P] where P = (F_o² + 2F_c²)/3
wR(F²) = 0.156	(Δ/σ)_max < 0.001
S = 1.36	Δρ_max = 1.40 e Å⁻³
3809 reflections	Δρ_min = −1.01 e Å⁻³
213 parameters	Absolute structure: Refined as an inversion twin
1 restraint	Absolute structure parameter: 0.18 (6)

Special details top

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.

Refinement. Refined as a two-component inversion twin All H atoms were placed geometrically and refined using a riding-model approximation, with C—H distances of 0.93 (aromatic), 0.97 (methylene) or 0.96 Å (methyl), and N—H distances of 0.89 Å. The torsion angles of the methyl and ammonium H atoms were allowed to refine to best fit the experimental electron density map, and the U_iso(H) values of the these groups were constrained to 1.5 times that of their carrier atom. For the other hydrogen atoms U_iso was set to 1.2 times U_eq of the carrier atom.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
C1	0.732 (2)	0.2421 (9)	0.275 (3)	0.057 (6)
C2	0.636 (2)	0.2194 (11)	0.189 (3)	0.062 (7)
H2	0.578512	0.239423	0.133959	0.074*
C3	0.628 (2)	0.1666 (11)	0.187 (3)	0.056 (6)
H3	0.565268	0.151337	0.125072	0.067*
C4	0.7094 (17)	0.1354 (8)	0.274 (3)	0.042 (5)
C5	0.8041 (18)	0.1597 (9)	0.363 (3)	0.046 (5)
H5	0.859752	0.140149	0.424816	0.055*
C6	0.815 (2)	0.2123 (9)	0.359 (3)	0.049 (6)
H6	0.879008	0.227882	0.416005	0.059*
C7	0.742 (3)	0.2997 (9)	0.270 (5)	0.103 (12)
H7A	0.776947	0.310150	0.161771	0.154*
H7B	0.793394	0.310999	0.363177	0.154*
H7C	0.663715	0.314629	0.282620	0.154*
C8	0.705 (2)	0.0772 (9)	0.264 (4)	0.064 (7)
H8A	0.693924	0.066588	0.144981	0.077*
H8B	0.781694	0.063220	0.304081	0.077*
C9	0.5269 (16)	0.3365 (8)	0.850 (3)	0.043 (5)
C10	0.617 (2)	0.3142 (10)	0.755 (4)	0.070 (8)
H10	0.685325	0.332821	0.725302	0.084*
C11	0.604 (3)	0.2637 (12)	0.702 (4)	0.074 (8)
H11	0.664217	0.249089	0.633743	0.088*
C12	0.506 (2)	0.2346 (8)	0.747 (3)	0.053 (6)
C13	0.4183 (19)	0.2578 (9)	0.842 (4)	0.060 (6)
H13	0.350192	0.239050	0.872581	0.072*
C14	0.4268 (17)	0.3085 (9)	0.894 (3)	0.046 (6)
H14	0.365046	0.323451	0.958389	0.056*
C15	0.496 (3)	0.1779 (11)	0.695 (5)	0.102 (12)
H15A	0.448471	0.159821	0.778411	0.153*
H15B	0.575688	0.163174	0.690046	0.153*
H15C	0.458851	0.175336	0.583038	0.153*
C16	0.540 (3)	0.3897 (10)	0.913 (3)	0.070 (8)
H16A	0.468909	0.398740	0.978443	0.084*
H16B	0.608749	0.390979	0.991197	0.084*
N1	0.6051 (15)	0.0563 (6)	0.373 (2)	0.044 (4)
H1A	0.619536	0.063181	0.483461	0.066*
H1B	0.600284	0.022474	0.357929	0.066*
H1C	0.535699	0.070774	0.341058	0.066*
N2	0.558 (2)	0.4277 (8)	0.780 (4)	0.091 (9)
H2A	0.636714	0.431734	0.760790	0.136*
H2B	0.526185	0.457349	0.814056	0.136*
H2C	0.522054	0.417394	0.683012	0.136*
Zn1	0.74939 (18)	0.47543 (8)	0.3213 (3)	0.0353 (5)
Br1	0.7646 (2)	0.56660 (8)	0.2732 (3)	0.0568 (7)
Br2	0.8370 (2)	0.44791 (8)	0.5903 (3)	0.0473 (5)
Br3	0.53762 (18)	0.45225 (9)	0.3424 (4)	0.0561 (6)
Br4	0.8535 (2)	0.43435 (8)	0.0869 (3)	0.0480 (6)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.069 (16)	0.056 (14)	0.046 (13)	0.003 (12)	0.001 (12)	0.008 (12)
C2	0.059 (16)	0.079 (19)	0.047 (14)	0.010 (14)	−0.011 (12)	0.017 (13)
C3	0.051 (14)	0.081 (19)	0.036 (12)	−0.014 (13)	−0.004 (11)	−0.011 (13)
C4	0.031 (10)	0.049 (12)	0.048 (12)	−0.003 (9)	0.010 (9)	−0.008 (11)
C5	0.036 (10)	0.072 (16)	0.029 (12)	0.008 (10)	−0.009 (9)	−0.004 (11)
C6	0.049 (12)	0.058 (15)	0.041 (13)	−0.014 (10)	0.010 (11)	−0.008 (11)
C7	0.16 (3)	0.032 (14)	0.12 (3)	−0.010 (18)	−0.01 (3)	0.023 (18)
C8	0.046 (13)	0.063 (16)	0.082 (18)	−0.003 (11)	0.019 (13)	0.008 (15)
C9	0.032 (10)	0.051 (12)	0.046 (12)	−0.004 (9)	−0.012 (11)	0.004 (11)
C10	0.049 (14)	0.071 (18)	0.09 (2)	−0.004 (13)	0.016 (14)	−0.025 (16)
C11	0.052 (16)	0.10 (2)	0.067 (18)	0.026 (16)	0.008 (14)	−0.021 (16)
C12	0.072 (16)	0.044 (13)	0.042 (13)	0.011 (12)	−0.019 (12)	−0.008 (10)
C13	0.048 (12)	0.068 (16)	0.063 (14)	−0.013 (11)	−0.011 (15)	−0.005 (15)
C14	0.021 (10)	0.082 (17)	0.036 (12)	0.000 (10)	0.006 (8)	0.007 (11)
C15	0.13 (3)	0.056 (18)	0.12 (3)	0.014 (19)	−0.04 (2)	−0.020 (19)
C16	0.082 (19)	0.073 (18)	0.055 (15)	−0.012 (16)	−0.020 (15)	0.013 (15)
N1	0.055 (11)	0.044 (11)	0.033 (11)	0.006 (8)	−0.001 (8)	0.008 (8)
N2	0.11 (2)	0.046 (13)	0.11 (2)	0.011 (12)	0.059 (17)	−0.013 (14)
Zn1	0.0342 (10)	0.0417 (12)	0.0299 (10)	−0.0021 (9)	0.0006 (11)	0.0021 (10)
Br1	0.0774 (17)	0.0412 (12)	0.0519 (13)	−0.0059 (11)	0.0131 (12)	0.0037 (10)
Br2	0.0508 (12)	0.0592 (13)	0.0319 (10)	0.0072 (10)	−0.0009 (11)	0.0076 (13)
Br3	0.0352 (10)	0.0574 (14)	0.0757 (15)	−0.0107 (9)	0.0000 (13)	−0.0002 (14)
Br4	0.0532 (13)	0.0552 (13)	0.0355 (11)	0.0062 (10)	0.0054 (11)	−0.0036 (14)

Geometric parameters (Å, º) top

C1—C6	1.37 (3)	C11—C12	1.37 (4)
C1—C2	1.38 (3)	C11—H11	0.9300
C1—C7	1.51 (3)	C12—C13	1.36 (3)
C2—C3	1.38 (4)	C12—C15	1.54 (3)
C2—H2	0.9300	C13—C14	1.39 (3)
C3—C4	1.39 (3)	C13—H13	0.9300
C3—H3	0.9300	C14—H14	0.9300
C4—C5	1.41 (3)	C15—H15A	0.9600
C4—C8	1.52 (3)	C15—H15B	0.9600
C5—C6	1.38 (3)	C15—H15C	0.9600
C5—H5	0.9300	C16—N2	1.44 (3)
C6—H6	0.9300	C16—H16A	0.9700
C7—H7A	0.9600	C16—H16B	0.9700
C7—H7B	0.9600	N1—H1A	0.8900
C7—H7C	0.9600	N1—H1B	0.8900
C8—N1	1.49 (3)	N1—H1C	0.8900
C8—H8A	0.9700	N2—H2A	0.8900
C8—H8B	0.9700	N2—H2B	0.8900
C9—C14	1.37 (3)	N2—H2C	0.8900
C9—C10	1.37 (3)	Zn1—Br4	2.399 (3)
C9—C16	1.47 (3)	Zn1—Br2	2.404 (3)
C10—C11	1.38 (4)	Zn1—Br1	2.411 (3)
C10—H10	0.9300	Zn1—Br3	2.426 (3)

C6—C1—C2	120 (2)	C13—C12—C11	117 (2)
C6—C1—C7	122 (3)	C13—C12—C15	122 (3)
C2—C1—C7	118 (3)	C11—C12—C15	121 (3)
C3—C2—C1	119 (2)	C12—C13—C14	122 (2)
C3—C2—H2	120.5	C12—C13—H13	118.8
C1—C2—H2	120.5	C14—C13—H13	118.8
C2—C3—C4	122 (2)	C9—C14—C13	119 (2)
C2—C3—H3	118.9	C9—C14—H14	120.3
C4—C3—H3	118.9	C13—C14—H14	120.3
C3—C4—C5	117 (2)	C12—C15—H15A	109.5
C3—C4—C8	123 (2)	C12—C15—H15B	109.5
C5—C4—C8	120 (2)	H15A—C15—H15B	109.5
C6—C5—C4	120 (2)	C12—C15—H15C	109.5
C6—C5—H5	120.0	H15A—C15—H15C	109.5
C4—C5—H5	120.0	H15B—C15—H15C	109.5
C1—C6—C5	121 (2)	N2—C16—C9	115 (2)
C1—C6—H6	119.3	N2—C16—H16A	108.4
C5—C6—H6	119.3	C9—C16—H16A	108.4
C1—C7—H7A	109.5	N2—C16—H16B	108.4
C1—C7—H7B	109.5	C9—C16—H16B	108.4
H7A—C7—H7B	109.5	H16A—C16—H16B	107.5
C1—C7—H7C	109.5	C8—N1—H1A	109.5
H7A—C7—H7C	109.5	C8—N1—H1B	109.5
H7B—C7—H7C	109.5	H1A—N1—H1B	109.5
N1—C8—C4	111.0 (19)	C8—N1—H1C	109.5
N1—C8—H8A	109.4	H1A—N1—H1C	109.5
C4—C8—H8A	109.4	H1B—N1—H1C	109.5
N1—C8—H8B	109.4	C16—N2—H2A	109.5
C4—C8—H8B	109.4	C16—N2—H2B	109.5
H8A—C8—H8B	108.0	H2A—N2—H2B	109.5
C14—C9—C10	120 (2)	C16—N2—H2C	109.5
C14—C9—C16	120 (2)	H2A—N2—H2C	109.5
C10—C9—C16	120 (2)	H2B—N2—H2C	109.5
C9—C10—C11	119 (2)	Br4—Zn1—Br2	109.05 (11)
C9—C10—H10	120.3	Br4—Zn1—Br1	106.84 (11)
C11—C10—H10	120.3	Br2—Zn1—Br1	113.53 (12)
C12—C11—C10	122 (2)	Br4—Zn1—Br3	113.82 (13)
C12—C11—H11	119.0	Br2—Zn1—Br3	104.90 (12)
C10—C11—H11	119.0	Br1—Zn1—Br3	108.86 (11)

C6—C1—C2—C3	−2 (4)	C14—C9—C10—C11	1 (4)
C7—C1—C2—C3	178 (3)	C16—C9—C10—C11	178 (2)
C1—C2—C3—C4	3 (4)	C9—C10—C11—C12	−2 (5)
C2—C3—C4—C5	−1 (3)	C10—C11—C12—C13	2 (4)
C2—C3—C4—C8	−177 (2)	C10—C11—C12—C15	−177 (3)
C3—C4—C5—C6	−1 (3)	C11—C12—C13—C14	−1 (4)
C8—C4—C5—C6	174 (2)	C15—C12—C13—C14	178 (3)
C2—C1—C6—C5	0 (4)	C10—C9—C14—C13	1 (4)
C7—C1—C6—C5	180 (2)	C16—C9—C14—C13	−177 (2)
C4—C5—C6—C1	2 (3)	C12—C13—C14—C9	0 (4)
C3—C4—C8—N1	−76 (3)	C14—C9—C16—N2	−124 (3)
C5—C4—C8—N1	109 (2)	C10—C9—C16—N2	59 (4)

Hydrogen-bond geometry (Å, º) top

Cg1 and Cg2 are the centroids of the C1–C6 and C9–C14 benzene rings, respectively.

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2···Cg2ⁱ	0.93	2.94	3.73 (3)	143
C14—H14···Cg1ⁱⁱ	0.93	2.94	3.72 (2)	143
C8—H8B···Br3ⁱⁱⁱ	0.97	2.88	3.81 (2)	161
C8—H8A···Br1^iv	0.97	2.91	3.82 (3)	157
C16—H16B···Br4^v	0.97	3.03	3.90 (3)	150
N1—H1A···Br1^vi	0.89	2.58	3.427 (17)	159
N1—H1B···Br2^iv	0.89	2.92	3.626 (17)	137
N1—H1B···Br4^vi	0.89	2.94	3.613 (16)	133
N1—H1C···Br2^vii	0.89	2.96	3.414 (17)	113
N1—H1C···Br4^vii	0.89	2.82	3.563 (17)	142
N2—H2A···Br2	0.89	2.61	3.46 (2)	159
N2—H2B···Br3^viii	0.89	2.47	3.34 (2)	166
N2—H2C···Br3	0.89	2.79	3.45 (3)	132

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

Acknowledgements

The authors are thankful to the Sophisticated Analytical Instrument Facility (SAIF), IITM, Chennai 600 036, Tamilnadu, India for the single-crystal X-ray diffraction data.

Funding information

Funding for this research was provided by the Council of Scientific and Industrial Research (CSIR), New Delhi, India [grant No. 03(1301)13/EMR II to CR].

References

Bruker (2016). APEX3, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Dolbecq, A., Dumas, E., Mayer, C. R. & Mialane, P. (2010). Chem. Rev. 110, 6009–6048. Web of Science CrossRef CAS PubMed Google Scholar
Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854. Web of Science CrossRef CAS IUCr Journals Google Scholar
Jiang, M. & Fang, Q. (1999). Adv. Mater. 11, 1147–1151. CrossRef CAS Google Scholar
Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466–470. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Sheldrick, G. M. (2015a). Acta Cryst. A71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (2015b). Acta Cryst. C71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Spek, A. L. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925. Web of Science CrossRef CAS IUCr Journals Google Scholar