Substrate-adsorbate distance

We further assume that the phenyl rings of the TMA molecules are located in threefold hollow sites of Au(lll). The corresponding model is depicted in Fig. lOD (Table 1). We notice that the substrate-adsorbate interaction ( 7r-ring in threefold hollow sites) reduces the distance between the TMA centers of one centrosymmetric dimer by approximately 10%. The model predicts further the misalignment of the dimer axis by - 5° with respect to the [110] substrate direction, which results from the directional nature of hydrogen bonds in the alternating arrangement of centrosymmetric and macrocyclic dimers. 

Free Enzymes in Flow Reactors. Substitute t = zju into the DDEs of Example 12.5. They then apply to a steady-state PFR that is fed with freely suspended, pristine enzyme. There is an initial distance down the reactor before the quasisteady equilibrium is achieved between S in solution and S that is adsorbed on the enzyme. Under normal operating conditions, this distance will be short. Except for the loss of catalyst at the end of the reactor, the PFR will behave identically to the confined-enzyme case of Example 12.4. Unusual behavior will occur if kfis small or if the substrate is very dilute so Sj Ej . Then, the full equations in Example 12.5 should be (numerically) integrated. 

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