Preparation of Sodium Monofluorophosphate by the Reactions of Various Sodium Phosphates with Sodium Fluoride
Year: 1974
Type: article
Abstract: Sodium monofluorophosphate (I) was prepared by the reaction of sodium fluoride with various sodium phosphates, the reaction conditions and difference in the amount of I according to the starting material used were examined, and the results were as follows : (1) Although I is not formed by the reaction of NaF with sodium ortho-, pyro-, or tripoly- phospates, it can be produced from these phosphates when P2O5 was added, even at such a low temperature as 200°.(2) In the case of chain polyphosphates, the amount of I produced increases with the chain length, but its yield becomes almost constant when n^- is longer than 12.(3) In case of ring phosphates, I is readily produced, and sodium tetrametaphosphate can give I in a better yield than sodium trimetaphosphate. (4) The reaction of a mixture of NaF, P2O5, and Na2CO3 gives I in a good yield, and a mixture of NaF and P2O5 also gives I but contaminated with impurities. These results show that the yield of I varies according to the phosphates used as the starting material, heating temperature, and heating time. The optimum condition for preparing I seems to be to heat for a short time (6 min) at a high temperature (700-800°) when long-chain (n^-≥12) or ring phosphates are used, and to add P2O5 and heat for a long time (60 min) at a low temperature (300-500° in case of the orthophosphate, 600° in case of pyro- and tripoly-phosphates) when short-chain polyphosphates are used. Further, I can also be prepared by heating a mixture of P2O5, Na2CO3, and NaF.
Source: YAKUGAKU ZASSHI
Language: English
Subfield: Inorganic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2437096240