LAUSR

Reaction of poorly soluble manganese(II) bis(1-hydroxyethylidene)diphosphonate tetrahydrate Mn(H3L)2 · 4H2O with 2-aminoethanol H2NCH2CH2OH in an aqueous solution on heating to 70–80°C causes the initial formation of soluble tris(2-hydroxyethanaminium) manganese(II) bis(1-hydroxyethylidene) diphosphonate Mn(H3L)2 · 3H2NCH2CH2OH · 4H2O, which next disproportionates into poorly soluble 2-hydroxyethanaminium manganese(II) (1-hydroxyethylidene)diphosphonate MnH2L · H2NCH2CH2OH and metal-cation-free coordination polymer of (1-hydroxyethylidene)diphosphonic acid with 2-aminoethanol. Poorly soluble MnH2L · H2NCH2CH2OH can be readily converted into the soluble form by treatment with 2-aminoethanol or 2-amino-2-(hydroxymethyl)propane-1,3-diol H2NC(CH2OH)3.