Rhodium dicarbonyls on dealuminated

Fig. 1. Model of rhodium dicarbonyl complex on dealuminated Y zeolite, as determined by IR and EXAFS spectroscopies and density functional theory. The Rh atom, near the upper center of the figure, has two CO ligands bonded to it, pointing upward, and two oxygen atoms of the zeolite lattice below. An Al atom is located between these two oxygen atoms. The dangling atoms of the cluster model of the zeolite are capped by hydrogen atoms for the calculation (Goellner, Gates, etal., 2000).

Some of the most thoroughly characterized supported metal complexes are zeolite-supported metal carbonyls. These have been prepared, for example, by the adsorption of Rh(CO)2(acac) on zeolites (e.g., the faujasite zeolite NaY [26] or dealuminated zeolite Y [27]) followed by CO treatment of the resultant material (Fig. 19.3). The IR spectra (not shown, but found in [26, 27]) of the rhodium dicarbonyl represented in Fig. 19.3 are consistent with a square-planar complex (formally Rh(I)) with the Rh atom bonded to two zeolite oxygen atoms. 

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