Simultaneous Determination of Structural and Kinetic Parameters Characterizing the Interconversion of Highly Dispersed Species: the Interaction of NO with RhI(CO)2/γ-Al2O3

Energy-dispersive EXAFS (EDE), combined with mass spectrometry and a flow microreactor system, has been used to investigate the reaction of an Al 2 O 3 -supported Rh I (CO) 2 species with NO. This combined in situ approach uniquely permits a priori analysis of the structures of the species involved (on a time scale of ca. 2 s) and simultaneous determination of reaction mechanism and kinetic parameters. In the current case, it is found that the Al(O)Rh I (CO) 2 Cl species reacts to form an intermediate Al(O)Rh(NO) 2 Cl Cl species (ν ≈ 0.357 ± 0.125 s -1, E act ≈ 11 ± 1.25 kJ mol -1 ), which subsequently forms an (AlO) 2 Rh(NO) - Cl species and N 2 O (g) (ν ≈ 2 ± 0.5 × 10 4 s -1, E act ≈ 40 ± 3.5 kJ mol -1 ) showing a bent (134°) RhNO bond. This combination of rapid and complementary techniques should be applicable to a wide range of disciplines where quantitative structural and kinetic determinations are of importance.