The incorporation of Cp * [Cp * = η 5 -(CH 3 ) 5 C 5 ] complexes of rhodium in Y-type zeolites has been studied. The preparation and characterization of intrazeolite complexes derived from (Cp * RhCl) 2 (μ-Cl) 2 (1) and Cp * Rh(S) + 3 (3) (where S=H 2 O and CH 2 Cl 2 ) are described. The reactivity of the rhodium complexes with carbon monoxide was followed by infrared spectroscopy. The nature of the CO adducts was found to be dependent on the type of charge-balancing cation. Intrazeolite complexes were characterized in H + , Li + , Na + and Cs + partially exchanged forms of zeolite Y. Additionally, the reaction of free Cp * ligand with intrazeolite rhodium (I) dicarbonyl species is described.