Low temperature synthesis of ionic phosphates in dimethyl sulfoxide

Abstract

A new synthesis route for phosphates in an organic solvent at low temperatures is presented. The synthesis was done by dispersing a nitrate salt and phosphorus pentoxide in dimethyl sulfoxide. The synthesis can be performed under water-free conditions and yielded several organic and inorganic phosphates. Crystal structure solution of bistetramethylammonium hydrogencyclotriphosphate, [N(CH3)4]2HP3O9, was achieved by combining information gained from powder X-ray diffraction, liquid NMR and solid state (2D) NMR. The molecular structure of rubidium cyclotetraphosphate, Rb4P4O12, was determined using liquid state NMR and solid state (2D) NMR spectroscopy.

Investigation of Bistetramethylammonium Hydrogencyclotriphosphate—A Molecular Rotor?

“…Thus, cations bigger than Cs + like the tetramethylammonium cation are desirable. From literature only the tetramethylammonium orthophosphates [N(CH 3 ) 4 ]H 2 PO 4 ⋅ 0.5 H 2 O, [N(CH 3 ) 4 ]H 2 PO 4 ⋅ H 2 O, and the metaphosphates α‐ and β‐[N(CH 3 ) 4 ] 2 HP 3 O 9 , which contain the more bulky anion P 3 O 9 3− , are known …”

“…From literatureo nly the tetramethylammonium orthophosphates [N(CH 3 ) 4 ]H 2 PO 4 ·0.5 H 2 O, [11] [N(CH 3 ) 4 ]H 2 PO 4 ·H 2 O, [12] and the metaphosphates a-a nd b-[N(CH 3 ) 4 ] 2 HP 3 O 9 ,w hich contain the more bulky anion P 3 O 9 3À ,are known. [13,14] For the conduction mechanism of high-temperature ionic conductors, two different mechanisms are discussed in literature. Some authors try to explain the high temperature conductivity with ap ercolation-type mechanism.…”

Festkörperchemie 2014

“…Ebenfalls unkompliziert erscheint eine wasserfreie Syntheseroute für die organischen und anorganischen Phosphate, die Schmedt auf der Günne vorgestellt hat 4. Dabei werden Salznitrate und P4O10 in Dimethylsulfoxid umgesetzt.…”

Synthesis and characterization of methylammonium phosphates as crystalline approximants for anhydrous, low melting phosphate glasses

“…The rst had been synthesized via the Boullé process 22 which requires silver salts as starting material. A larger version of the ammonium ion is the tetrasubstituted tetramethylammonium ion [N(CH 3 ) 4 ] + , for which several phosphate phases [23][24][25] and phase transitions 26,27 between them have been observed. Methylammonium hydrogenphosphate (254.2 C) and methylammonium formate (162.1 C) have low decomposition temperatures.…”

“…Methylammonium hydrogenphosphate (254.2 C) and methylammonium formate (162.1 C) have low decomposition temperatures. 28 Thus for their synthesis in general low synthesis temperature are required, for example making use of solvents like dimethyl sulfoxide 23,29 or water.…”