Polymeric Hydrogen-Bonded Supermolecules by Self-Assembling of Hexakis(4-Pyridylcarbinoxy) Cyclotriphosphazene and Dicarboxylic Acids

Abstract

Hexakis(4-pyridylcarbinoxy)cyclotriphosphazene (PyPN) and terephthalic acid (TPA) self-assembled into polymeric supermolecules through hydrogen bonding between carboxyl and pyridyl groups. Two supermolecular self-assemblies were obtained: crystals 1 composed of 2:1 TPA/PyPN from DMF/ DMSO, and crystals 2 composed of 3:1 TPA/PyPN from DMF. The former is monoclinic, space group C2/c with a = 26.029 Å, b = 7.854 Å, c = 28.073 Å, β = 116.47°, V = 5138 ų, and Z = 4. The structure was defined to R = 0.064 based on 2832 data, I>1.5 σ(I). The X-ray analysis revealed that PyPN is joined with two TPA molecules through hydrogen bonding to form a polymeric assembly. The self-assembly obtained from DMF seems to take a cylindricalshaped structure, i.e., all of pyridyl group in PyPN participate in the formation of the assembly, as evidenced by elemental analysis, FT-IR spectroscopy and X-ray diffraction data. These results and the role of the solvent are described.