Preparation, Crystallographic Characterization, Synthon Investigation and Hirshfeld Surface Analysis of 4-bromobenzamide and its Cocrystals with Phenylacetic Acid and 2,3-Dibromosuccinic Acid

The crystalline solids 4-bromobenzamide (bbm) and its two new cocrystals with phenylacetic acid and 2,3-dibromosuccinic acid are featured through using the XRD analysis, IR, mp, and elemental analysis. Although the structure of the bbm is reported, we redetermine its crystal structure in order to make some comparison in the geometric parameters between bbm and its cocrystals discussed in the following text. The bbm (1) applies the monoclinic, space group P2(1)/c, with a = 4.9735(4) Å, b = 5.4545(5) Å, c = 28.178(3) Å, β = 93.6180(10)°, V = 762.90(12) Å3, Z = 4. Cocrystal (2) crystallizes into the triclinic, space group P1̄ , with a = 5.6582(4) Å, b = 10.1682(8) Å, c = 12.9486(9) Å, α = 102.781(2)°, β = 94.8340(10)°, γ = 92.3000(10)°, V = 722.61(9) Å3, Z = 2. Cocrystal (3) belongs to the monoclinic, space group P2(1)/c, with a = 8.8220(7) Å, b = 9.2241(8) Å, c = 13.7529(11) Å, β = 92.6640(10)°, V = 1117.93(16) Å3, Z = 4. All of the three compounds 1-3 set up the multiple N–H⋯O H-bonds together with the other non-covalent linkages. Apart from the conventional H-bonds, the secondary linkages of the CH–O, CH–Br, Br–O, and Br–Br also show the essential roles in the spatial expansion. The role of these non-covalent linkages in the crystal packing is assured. Study by the Hirshfeld surface analysis (HSA) supplies the extra views into the nature of the various short contacts in the crystal structures. The synthons within these assemblies are analyzed. On account of the synergism of the conventional H-bonds and the various non-covalent contacts, they exhibited the 1D and 3D motifs. In conclusion, we have demonstrated that the high dimensional supramolecules can be manufactured by the collective non-covalent connections.