010ChemInform Abstract Three novel compounds are formed by the system Cs2O-Ga2O3-P2O5-H2O at 150-500 rc C, which can be isolated by crystallization: the diphosphate Cs2GaH3(P2O7)2 (I), the triphosphate CsGaHP3O10 (II) and the cyclododecaphosphate Cs3Ga3P12O36 (III). Their crystal structures are determined. (III) belongs to the space group Pa3; Z=4 and (I) to the space group P21/n; Z=2. The triphosphate (II) forms three modifications (I, II, and III). An X-ray analysis reveals that CsGaHP3O10-II has the same structure as the known KGaHP3O10. The thermolysis of CsGaHP3O10-I, -II, and -III or of (I) gives rise to the formation of the novel CsGaP2O7.

Mixtures of Cs2CO3, Ga2O3 and 85% H3PO4, i.e. the system Cs2O‐Ga2O3‐P2O5‐H2O, are heated to 150‐460 °C for 5‐30 d. A 15:1‐ratio is chosen for P2O5:Ga2O3 and 2.5:1‐, 5:1‐, 7.5:1‐ and 10:1‐ratios are chosen for Cs2O:Ga2O3.

034ChemInform Abstract Mixtures of Ga2O3, NH4H2PO4 or (NH4)2HPO4 and 85% H3PO4 are heated to 150-350 rc C to yield the novel title compounds NH4GaP2O7, NH4GaHP3O10-I and -II and (NH4)2Ga2P8O24. The most stable among these, NH4GaHP3O10-II, on heating to 450 rc C yields the known cyclohexaphosphate Ga2P6O18 (form B).