Alkoxides of the type (RO)nE-X-A in which a functional organic group A is connected to the alkoxide moiety via an inert and hydrolytically stable spacer X, are used to bind metal complex moieties. Sol-gel processing of the resulting metal complexes [(RO)nE-X-A]yMIm under standard conditions results in the formation of metal complex containing gels. If the metal complex moiety MLm is catalytically active, this method results in the heterogenization of homogeneous catalysts. Another application of the metal complex substituted gels is the preparation of composites containing uniform, nanometer-sized metal particles homogeneously dispersed in a ceramic matrix.