Table 1. Experimental details.

	1	2	3	4
Crystal data
Chemical formula	C14H9BrS2	C14H9IS2	C14H9BrSe2	C14H9ISe2
M r	321.24	368.23	415.04	462.03
Crystal system, space group	Monoclinic, P21/c	Monoclinic, P21/c	Monoclinic, P21/c	Monoclinic, P21/c
Temperature (K)	296	294	297	292
a, b, c (Å)	8.2471 (8), 9.9562 (8), 15.7601 (14)	8.4872 (3), 9.9629 (4), 15.6485 (7)	12.3864 (11), 13.6816 (11), 8.0982 (6)	12.9606 (6), 13.5999 (7), 8.0448 (4)
β (°)	98.967 (3)	97.052 (1)	96.398 (3)	95.585 (2)
V (Å3)	1278.2 (2)	1313.18 (9)	1363.82 (19)	1411.27 (12)
Z	4	4	4	4
Radiation type	Mo Kα	Mo Kα	Mo Kα	Mo Kα
μ (mm−1)	3.51	2.73	8.33	7.40
Crystal size (mm)	0.28 × 0.21 × 0.14	0.16 × 0.13 × 0.05	0.17 × 0.17 × 0.12	0.51 × 0.47 × 0.24
Data collection
Diffractometer	Bruker D8 Venture/Photon 100 CMOS	Bruker D8 Venture/Photon 100 CMOS	Bruker D8 Venture/Photon 100 CMOS	Bruker D8 Venture/Photon 100 CMOS
Absorption correction	Multi-scan (SADABS; Krause et al., 2015 ▸)	Multi-scan (SADABS; Krause et al., 2015 ▸)	Multi-scan (SADABS; Krause et al., 2015 ▸)	Multi-scan (SADABS; Krause et al., 2015 ▸)
T min, T max	0.628, 0.746	0.690, 0.746	0.543, 0.746	0.390, 0.746
No. of measured, independent and observed [I > 2σ(I)] reflections	55020, 3078, 2559	56046, 3001, 2585	43875, 2976, 2208	54241, 3391, 2702
R int	0.041	0.045	0.060	0.054
(sin θ/λ)max (Å−1)	0.660	0.650	0.639	0.660
Refinement
R[F 2 > 2σ(F 2)], wR(F 2), S	0.029, 0.073, 1.04	0.022, 0.051, 1.08	0.035, 0.069, 1.03	0.037, 0.083, 1.04
No. of reflections	3078	3001	2976	3391
No. of parameters	190	190	154	190
H-atom treatment	All H-atom parameters refined	All H-atom parameters refined	H-atom parameters constrained	All H-atom parameters refined
Δρmax, Δρmin (e Å−3)	0.41, −0.76	0.45, −0.86	0.93, −0.90	1.14, −1.82

Computer programs: APEX3 (Bruker, 2015 ▸), SAINT (Bruker, 2002 ▸), SHELXL97 (Sheldrick, 2008 ▸), SHELXT (Sheldrick, 2015a ▸), SHELXL2018/3 (Sheldrick, 2015b ▸), DIAMOND (Brandenburg & Putz, 2006 ▸) and WinGX (Farrugia, 2012 ▸).