| Abstract | Supramolecular reactions were performed between 2,2‘-bipyrimidine (BPM) and 2,5-substituted cyano- and haloanilic acids [cyananilic acid (CNA), chloranilic acid (ClA), and bromanilic acid, (BrA)] under identical reaction conditions in methanol and a mixture of acetonitrile and methanol. The cyano and hydroxyl functional units of CNA in supramolecular compound 1 are hydrogen-bonded through water molecules and form a two-dimensional network with a grid motif. The grid cavities are occupied by BPM molecules, which are strongly linked by water molecules that connect to the CNA network. The supramolecular architecture of 1 thus consists of a three-dimensional hydrogen-bonded network. The 1:1:2 (H2O) compound 2 has intermolecular O−H···O and O−H···N hydrogen bonds: (i) ClA···H2O···BPM linked along the diagonal line of the bc-plane and (ii) BPM···H2O···BPM connected along the b-axis. This structure includes strong Cl···Cl interactions at 3.34 Å, which generate a three-dimensional packing arrangement as strengthened by acid···acid interaction. A new class of hydrogen-bonded 1:1:4 (H2O) supramolecular compound 3 is formed from BPM, BrA, and water molecules, where structure formation is directed by O−H···O and O−H···N hydrogen bonds, as well as weaker C−H···O and C−H···Br interactions between BPM and BrA. Remarkable Br···Br interactions at 3.68 Å are observed that are similar to the Cl···Cl interactions in 2. The three supramolecular compounds have been prepared with the specific aim of assessing a new donor−acceptor-type of hydrogen-bonded interactions to control the architecture of organic solids for the further invention of supramolecular solid-state materials. |
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