A Novel Supramolecular Resin Based On an Organic Acid−Base Compound

A novel supramolecular resin, namely, α-(AEDPH2)·(enH2)·3H2O (1) (AEDPH2 = 1-aminoethylidenediphosphonic acid and en = ethylenediamine), is synthesized and characterized by infrared (IR) spectroscopy, thermogravimetric analysis (TGA), elemental analysis (EA), single crystal X-ray diffraction (SCD), and powder X-ray diffraction (PXRD). The supramolecular resin is an organic acid−base compound and shows a three-dimensional (3D) tessellate-type supramolecular structure constructed via various hydrogen bonds, which contains a kind of D3 water cluster. It has good mechanical properties as well as excellent flame retardant performance. In addition, the supramolecular resin can form a single crystal, namely, β-(AEDPH2)·(enH2)·3H2O (2), by an interesting gel-to-crystal transformation. Compound 2 is the isomer of 1 which illustrates a sandwich-type supramolecular architecture contained an R4 water cluster.