Crystal structure and solution-state study of K[Al(mal)2(H2O)2]·2H2O (H2mal = malonic acid)
Abstract
The new complex K[Al(mal)2(H2O)2]·2H2O [H2mal = CH2(CO2H)2] has been synthesized and its crystal structure determined by X-ray crystallography. An investigation of metal speciation in aqueous solution (analytical concentration around 50 mmol dm–3) by using 27Al, 1H and 13C NMR spectroscopies revealed that, in solutions at physiological pH (7.5), the bis(malonate) complex evolves to the tris(malonate), [Al(mal)3]3–, without precipitation of aluminium hydroxide.