Intercalation of polymerized 3-methyl- and 3,4-dimethyl-pyrrole in the VOPO4 interlayer space

Abstract

3-Methylpyrrole (3-Mepyrr) and 3,4-dimethylpyrrole (3,4-Me₂pyrr) react with powdered VOPO₄·2H₂O suspended in ethanol to yield intercalation compounds consisting of the reduced VOPO₄ lattice and poly-3-Mepyrr or poly-3,4-Me₂pyrr chains, VOPO₄·(H₂O)_1.4(EtOH)_0.2·(MeC₄HNH)_0.65 and VOPO₄(H₂O)_1.8·(EtOH)_0.2·(Me₂C₄NH)_0.6. Poly-3-Mepyrr and poly-3,4-Me₂pyrr moieties in the VOPO₄ interlayer space afford single interlayer spacings of 8.2 and 9.7 Å, respectively Pyrrole (Pyrr) also reacts with VOPO₄·2H₂O solids suspended in ethanol to yield an oxidatively polymerized compound formed on the surface of the VOPO₂ grains. Factors causing the polymerization of 3-Mepyrr and 3,4-Me₂pyrr in the VOPO₂ interlayer space and electronic interactions of the reduced VOPO₄ host lattice with the intercalated poly-3-Mepyrr and poly-3,4-Me₂ pyrr moieties are described based on powder X-ray diffraction patterns, infrared and X-ray photoelectron spectra together with theoretical calculations of molecular geometries and electron spin densities