phosphoric acid in water
concd. aq. KNCO added slowly to chilled (0°C) concd. phosphoric acid under vac.; trapped at liq. N2-temp., distilled at -30°C;
参考文献
Ellingboe, L. C.; Bopegedera, A. M. R. P.; Brazier, C. R.; Bernath, P. F.
Chemical Physics Letters, 1986 , vol. 126, p. 285 - 289