Molecular recognition studies of supramolecular edifices
of thiobenzamide, 1, and its hetero analogues, o- and p-isomers of pyridinethioamides, 2 and 3, respectively, have been reported highlighting
the recognition
patterns of the thioamides with different aza-donor compounds having
variable conformational flexibility and dimensions, for example, 4,4′-bipyridine
(bpy, a), 1,2-bis(4-pyridyl)ethene (bpyee, b), 1,10-phenanthroline (110phen, c), and phenazine (phenz, d). The analysis reveals that thioamides 1–3 produce
co-crystals, 1(a–d)−3(a–d), respectively,
with the corresponding aza-donors. These structures, determined by
single-crystal X-ray diffraction, reveal that in all co-crystals,
the aggregation of the coformers occurs through N–H···N
hydrogen bonds due to the establishment of recognition between the
thioamide moiety and the N-hetero atom and is further
augmented by C–H···S hydrogen bonds. Analysis
of hydrogen-bonding patterns reveals several structural similarities
and differences among co-crystals, with the formation of different
types of three-dimensional structures in the form of herringbone,
layer, and sandwich. A systematic evaluation of solid-state structures
was performed in terms of the interplay of competing intermolecular
interactions within the crystal lattices and packing features of the
resulted exotic architectures, BFDH morphology predictions, and isostructural
analysis through cell-similarity index, powder X-ray diffraction similarity,
etc. Furthermore, the importance of each type of intermolecular interaction,
in particular, N–H···N, N–H···S,
C–H···S, etc., has been quantified by Hirshfeld
surface analysis. In addition, the energy contribution of all interactions
is computed by developing energy frameworks using Crystal Explorer.
