Synthesis and Control of Single Layer and Polar 2-D Layered Architectures in a Series of Organic Layered Solids

The syntheses and single crystal X-ray structures of five new lamellar solids based on the reaction of 3,5-pyrazole dicarboxylic acid (H2PzDCA) with five amines are described here. This reaction was studied to ascertain how the dimensions of an organic substituent influence the architecture of the layered solid. As expected, all of the structures display identical hydrogen bonded sheets akin to those found in previous work. However, increasing the width of the organic substituent influences the type of architecture observed, and here we report the first examples of single layers found in a series of heretofore exclusively bilayered ammonium HPzDCA salts. Most importantly, a very unusual polar layered solid was obtained in an intermediate size regime. This work identifies the influence of the size of substituents in engineering bilayer vs. polar vs. single layer architectures of ammonium HPzDCA salts.