Pentacoordinated germanium in AST zeolite synthesised in fluoride media. A 19F NMR validated computational study

A computational study shows that Ge is pentacoordinated in the double four rings (D4R) of Si/Ge AST zeolites; the calculated chemical shifts of F-D4R containing 8Si, 7Si1Ge and 8Ge reproduce the trends of 19F NMR experiments.