IR and 13C NMR investigations of the hydrolytic stabilities of the saturated and unsaturated ß-keto ligands acetylacetone (ACAC), ethylacetoacetate (EAA), allylacetoacetate (AAA), methacryloxyethyl-acetoacetate (MEAA) of the Al-, Ti- and Zr-butoxide complexes show a strong dependence on the type of the metal alkoxide and the structure of the organic ligands. The hydrolytic stabilities of the ligands decrease in the order Al->Zr->Ti-alkoxide and ACAC>AAA>EAA≥MEAA. Sol-gel reactions of complexes having a weak ligand stability leads to a larger water consumption and to larger particle sizes in sols than those with stable ACAC ligands. Heterometal bonds, i.e. Si-O-Al, Si-O-Ti and Si-O-Zr, in the system diphenylsiloxanediol/ metal alkoxide (complex) proved by 29Si and 17O NMR are hydrolysed to a different extent depending on the water amount, the type of the Si-O-M bond and the structure of the heterometal species. The degradation of the heterometal bonds leads to a separation of MO-M and Si-O-Si bonds which can entail a decreased homogeneity of the materials at a molecular level.