Table 2. Experimental details.

	RCN-I	RCN-II	RCN-III	RNC-II
Crystal data
Chemical formula	C7H2Br3N	C7H2Br3N	C7H2Br3N	C7H2Br3N
M r	339.83	339.83	339.83	339.83
Crystal system, space group	Monoclinic, P21/m	Orthorhombic, P n m a	Orthorhombic, P n m a	Orthorhombic, P n m a
Temperature (K)	173	173	173	173
a, b, c (Å)	4.8742 (15), 10.247 (3), 8.683 (3)	13.6183 (13), 10.2147 (10), 12.4754 (12)	20.399 (4), 10.2167 (18), 12.493 (2)	13.5916 (18), 10.1464 (13), 12.6158 (16)
α, β, γ (°)	90, 94.97 (1), 90	90, 90, 90	90, 90, 90	90, 90, 90
V (Å3)	432.0 (2)	1735.4 (3)	2603.7 (8)	1739.8 (4)
Z	2	8	12	8
Radiation type	Mo Kα	Mo Kα	Mo Kα	Mo Kα
μ (mm−1)	13.93	13.88	13.87	13.84
Crystal size (mm)	0.50 × 0.15 × 0.10	0.25 × 0.20 × 0.07	0.50 × 0.15 × 0.10	0.40 × 0.35 × 0.20
Data collection
Diffractometer	Bruker 1K area detector	Bruker 1K area detector	Bruker 1K area detector	Bruker APEXII CCD
Absorption correction	Multi-scan (SADABS; Bruker, 2002 ▸)	Multi-scan (SADABS; Bruker, 2002 ▸)	Multi-scan (SADABS; Bruker, 2002 ▸)	Multi-scan (SADABS; Bruker, 2002 ▸)
T min, T max	0.080, 0.248	0.06, 0.37	0.054, 0.337	0.170, 0.333
No. of measured, independent and observed [I > 2σ(I)] reflections	4093, 1024, 856	16607, 2093, 1692	22804, 2691, 2165	19459, 2105, 1638
R int	0.127	0.052	0.055	0.078
(sin θ/λ)max (Å−1)	0.649	0.650	0.616	0.650
Refinement
R[F 2 > 2σ(F 2)], wR(F 2), S	0.046, 0.116, 1.01	0.028, 0.063, 1.02	0.023, 0.046, 1.07	0.025, 0.055, 1.06
No. of reflections	1024	2093	2691	2105
No. of parameters	58	115	173	116
H-atom treatment	H-atom parameters constrained	H-atom parameters constrained	H-atom parameters constrained	H-atom parameters constrained
Δρmax, Δρmin (e Å−3)	1.36, −1.28	0.44, −0.69	0.56, −0.49	0.44, −0.48

Computer programs: SMART, APEX2 and SAINT (Bruker, 2002 ▸), SHELXT (Sheldrick, 2015a ▸), SHELXL2014 (Sheldrick, 2015b ▸), Mercury (Macrae et al., 2008 ▸), SHELXTL (Sheldrick, 2008 ▸), enCIFer (Allen et al., 2004 ▸), and publCIF (Westrip, 2010 ▸).