A paste of freshly prepared hydrous
tin(I1) oxide was refluxed with aqueous formic acid of various concentrations (150 ml. of 30-
100% w/w) under oxygen-free nitrogen until it dissolved (ca. 2 hr.). The solution was filtered
hot and cooled, and the white crystalline product filtered off, washed, and dried as in method (1).
Pure crystalline tin(t1) formate was obtained by this method but the yields (maximum 50%)
were poor |