A solid-phase synthesis protocol has been developed for the stepwise assembly of mixed-metal dinuclear complexes built from chromium, molybdenum and tungsten and a directional bridging ligand. Complexes with all nine possible metal combinations have been prepared on polystyrene/divinylbenzene copolymer employing a metal-complex-compatible silyl ether linker. Release of the metal complexes from the polymeric support is accomplished by fluoridolysis under mild conditions. The metal sequence in these complexes is pre-

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Monodisperse oligomers play a central role in understanding the chemistry and the physics of polymeric organic and inorganic materials.[1] The synthesis of monodisperse oligomers can be achieved by self-organization processes, random synthesis followed by separation processes, or by a step-bystep synthesis. All these strategies present their own advantages and disadvantages. Full control over chain length, end groups, and building-block sequence can be achieved using a stepwise approach. While this strategy is conceptually straightforward, it becomes increasingly tedious for higher oligomers owing to the purification steps needed. A particular elegant method for a repeated stepwise synthesis is the solidphase synthesis methodology which allows the purification of all intermediates by simple filtration. This strategy has been successfully applied to the synthesis of organic oligomeric compounds [2] while organometallic oligonuclear complexes have not been prepared in a stepwise manner by solid-phase synthesis. Mononuclear metal complexes have been prepared by solid-phase synthesis [3][4][5][6][7][8][9][10][11][12] for example, for biolabeling purposes or oligonucleotide-DNA/RNA binding studies and a dinuclear complex [13] has been synthesized by simultaneous double metalation of a peptide bound to a solid phase.We have already designed a system (polystyrene (PS)/ divinyl benzene-silyl ether linker-bidentate Schiff base ligand; 1 b in Scheme 1) which allows standard reactions of coordination and organometallic chemistry to be performed under solid-phase reaction conditions and the release of the final products from the insoluble matrix by fluoridolysis of the silyl ether linker. [14,15] The first application of this solid-phase reaction system to the synthesis of di-and trimetallic complexes is reported herein.The molybdenum carbonyl complexes reported herein possess several properties which make them suitable for solidphase synthesis approach, these are: 1) substitutionally inert metal-ligand bonds (molybdenum-carbonyl and molybdenum-isonitrile bonds), 2) carbonyl and isonitrile ligands which serve as sensitive analytical probes for IR spectroscopic analysis of the solid-phase system, [16,17] 3) highly colored complexes which permits UV/Vis spectroscopic analysis of

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