Abstract: Transition metal complexes of the formula (Ia) or (Ib), in which the substituents and indices have the following meanings: M is titanium, zirconium, hafnium, vanadium, niobium or tantalum or an element of the third subgroup of the Periodic Table or of the lanthanoids, X is fluorine, chlorine, bromine, iodine, hydrogen, C1-C10-alkyl, C6-C15-aryl, alkylaryl having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, —OR5 or —NR5R6, n is 1, 2 or 3, where n is the valency of M minus the number 2, Z is a three-way bridge and A and A1 are two-way bridges.

Abstract: The present invention relates to water-soluble, organosilylated cellulose ethers in which the organosilyl groups are attached hydrolysis-stably to the cellulose ethers and the remaining substituents on the silicon atoms of the organosilyl groups are likewise stable to hydrolysis. The cellulose ethers of the invention exhibit a strongly thickening action in aqueous solution, even at very low degrees of silylation, and are suitable as thickeners, for example, in paints, adhesives, and cosmetics. They are further suitable as protective colloids in the preparation of polymer dispersions.