Indirect Detection in Solution

Perhaps the most information packed experiment was performed by Bergman with the multiply labeled compound Cp Rh(PMe3)(13CH2CH3)D. This compound was observed to equilibrate with the isomer in which the deuteride 

Interactions of non-reactive unsaturated metal complexes with alkanes is documented in the studies by Rayner with the fragment [W(CO)5]. TRIR was used to look at the equilibrium between the bound and ligand-free complex. These data allowed determination of the actual enthalpy for coordination of the alkane to the unsaturated metal center. As seen in Table 5, there is a substantial interaction between most alkanes and the [W(CO)5] fragment, with methane being the most weakly bound (no complexation was observed) [45]. 

George and Poliakoff have reported that photolysis of CpRe(CO)3 in heptane solution produces a new dicarbonyl species that back reacts with added CO in a bimolecular reaction. The adduct was observed in the TRIR and was character- 

The equilibrium loss of dihydrogen from Ir(Pi-Pr3)2(r]2-H2)(H)2X complexes has been found to be strongly solvent dependent, as evidenced by the observation of vigorous effervescence when solid samples of Ir(Pz-Pr3)2(r 2-H2)(H)2X (X=C1, Br, or I) are dissolved in hydrocarbon solvents. Examination of the temperature dependence of the equilibria provided evidence that toluene reacts with all 3 five-coordinate species Ir(Pz-Pr3)2(H)2X,but that only the iodide complex interacted with alkane solvents. This conclusion was made based upon the smaller AH and AS values for the iodide complex equilibrium in alkane solvents, compared with the bromide and chloride complexes (Eq. 9) [47]. 

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