Preparation, Crystallographic Characterization, Synthon Investigation and Hirshfeld Surface Analysis of Two 3D Organic Adducts Derived from Salicylamide, Trichloroacetic Acid and 2,3-Dibromosuccinic Acid

The preparation, X-ray crystal structure, Fourier transform infrared (FTIR) spectroscopy, and elemental analysis of the two organic adducts derived from the salicylamide and the carboxylic acids are reported. XRD and FTIR analysis illustrated that 1 is an organic salt, while 2 belongs to a cocrystal. Salt 1 adopts the monoclinic, space group Cc, with a = 20.2877(19) Å, b = 12.0739(11) Å, c = 10.2892(9) Å, α = 90°, β = 107.512(3)°, γ = 90°，V = 2403.5(4) Å3, Z = 8. The cocrystal 2 crystallizes into the triclinic, space group $P\bar{1}$ , with a = 6.4730(6) Å, b = 8.0829(8) Å, c = 10.4601(9) Å, α = 107.089(2)°, β = 105.638(2)°, γ = 90.8710(10)°, V = 501.10(8) Å3, Z = 1. Here, the salicylamide at 1, 2 are both involved in the multiple conventional H-bonds. Apart from the conventional H-bonds, the auxiliary extending associates of CH⋯Cl, CH⋯O, O⋯O, O⋯Cl, O⋯Br, and CH-π also show critical roles in the space extension. Analysis by the Hirshfeld surface provides extra insights into the prevalence of the various short contacts in the crystal structures. The $\text{R}_{1}^{2}$ (5), $\text{R}_{2}^{1}$ (7), $\text{R}_{2}^{2}$ (8), $\text{R}_{4}^{2}$ (8), $\text{R}_{7}^{6}$ (26), $\text{R}_{8}^{6}$ (32), and $\text{R}_{8}^{8}$ (30) synthons were enclosed at the adducts. For the interplay of the conventional H-bonds plus the various non-covalent contacts, both adopt the 3D net. In conclusion, we demonstrat that 3D motifs can be constructed by the collective non-covalent interactions.