Synthesis and structure of the new gallophosphate Mu-6 containing a gallium organic complex as part of the framework

Abstract

A new gallophosphate was synthesized in aqueous medium using the macrocycle 1,4,8,11-tetraazacyclotetradecane as organic species. The structure was determined by single crystal X-ray diffraction. The symmetry is monoclinic, space group C2/c, a=0.8842(3)nm, b=1.7781(2)nm, c=1.5805(3)nm, β= 92.05(3)°. The structure consists of gallophosphate chains of gallium-corner-sharing Ga₂P₂O₄ four-rings. Each chain is connected to the others via a gallium-organic complex leading to a three dimensional framework. This new gallophosphate shows low thermal stability, a complete amorphization being observed after calcination at 350°C. The results of ¹³C and ³¹P solid state nmr spectroscopy are in agreement with the structure analysis.