Crystal Structures and Hirshfeld Surface Analyses of 6-Substituted Chromones

Here, we compare structures determined by X-ray diffraction and subsequent Hirshfeld surface analysis to identify and understand the non-covalent interactions within the lattices of chromone, 6-methylchromone, 6-methoxychromone, 6-fluorochromone, and 6-chlorochromone with reported 6-bromochromone. In chromone, H-bonds and CH-pi interactions predominate. H-bonds and aryl-stacking interactions are distinct in 6-methylchromone and 6-methoxychromone. The 6-fluorochromone, showed two types of H-bonds with O center dot center dot center dot H bonds having a greater contribution than F center dot center dot center dot H. In contrast, 6-chlorochromone and 6-bromochromone, the halogen contributes the larger percentage of stabilizing H-bonding with Cl center dot center dot center dot H and Br center dot center dot center dot H predominating over the O center dot center dot center dot H bonds. Compound 1 crystallizes in the monoclinic space group P2(1) /n with a = 8.1546(8) angstrom, b = 7.8364(7) angstrom, c = 11.1424(11) angstrom, beta = 108.506(2)degrees and Z = 4. Compound 2 crystallizes in the triclinic space group P-1 with a = 7.0461(3) angstrom, b = 10.2108(5) angstrom, c = 10.7083(5) angstrom, alpha = 89.884(2)degrees, beta = 77.679(2)degrees, gamma = 87.367(2)degrees and Z = 4. Compound 3 crystallizes in the monoclinic space group P2(1)/n with a = 8.1923(4) angstrom, b = 7.0431(3) angstrom, c = 15.3943(8) angstrom, beta = 92.819(2)degrees and Z = 4. Compound 4 crystallizes in the triclinic space group P1 with a = 3.7059(2) angstrom, b = 6.1265(4) angstrom, c = 7.6161(5) angstrom, alpha = 84.085(3)degrees, beta = 87.070(3)degrees, gamma = 83.390(3)degrees and Z = 1. Compound 5 crystallizes in the monoclinic space group P2 (1) with a = 3.8220(2) angstrom, b = 5.6985(2) angstrom, c = 16.9107(7) angstrom, beta = 95.8256(18)degrees and Z = 2. The effect of substituents at the 6-position on chromone on their crystal structures using Hirshfeld surface and fingerprint analysis. [GRAPHICS]