Heterocycles in organic materials chemistry. Synthesis of di-, tri-, and tetraimide polycarboxylic acids for use in organic network assembly

Seven linear divalent monomers, three bent divalent amide-containing monomers, 11 bent divalent ester-containing monomers, one planar trivalent monomer, and two tetrahedral tetravalent monomers were prepared by imide-forming condensation of the appropriate polyamine hub with a specially designed anhydride connector unit. These polyvalent polycarboxylic acid monomers were subjected to crystallization/photochemical crosslinking studies in an attempt to prepare periodic, covalent organic solids. Difficulties in achieving suitable crystals have so far frustrated efforts to reach this goal.