The synthesis of gallium phosphate frameworks with and without fluoride ions present: attempts to direct the synthesis of double four-ring containing materials

During attempts to synthesise gallium phosphate materials containing the double four-ring building unit, three pyridine-templated gallium fluorophosphates and one pyridine-templated gallium phosphate were prepared and their structures solved using single crystal X-ray diffraction experiments. None of the three fluorophosphates contained the double four-ring unit, while the material prepared in the absence of fluoride did. This overturns some of the conventional wisdom that fluoride is necessary to specifically form the double four-ring unit. The synthetic conditions needed to prepare the materials and possible relationships between the building units found in the solids are discussed.