Homogeneous catalytic systems frequently contain intermediates of one and the same nuclearity. For example, many well known hydrogenation systems are believed to consist of mono-nuclear intermediates alone, and these species exist on one or more catalytic cycles. More complex catalytic cycles have been discussed in the literature. In particular, the catalytic binuclear elimination reaction(CBER), a system containing both mononuclear and dinuclear intermediates has been the subject of considerable study. In the present talk, in-situ spectroscopic evidence is given for the existence of both homo-metallic and hetero-bimetallic CBER. FTIR spectroscopy is used as the anlytical tool and band-target entropy minimization (BTEM) is used as the primary numerical method.