In homogeneous catalysis, the catalyst is in the same phase as the reactant. The number of collisions between reactants and catalyst is at a maximum.In a patent, 1123-40-6, name is 4,4-Dimethylpiperidine-2,6-dione, introducing its new discovery. Safety of 4,4-Dimethylpiperidine-2,6-dione
The nitration of p-xylene, mesitylene, naphthalene, <2H8>naphthalene, durene and some related compounds has been followed by 15N NMR spectroscopy in a mixture of trifluoroacetic acid and nitromethane containing sufficient sodium azide to inhibit nitrous acid catalysed nitration.Significant 15N nuclear polarisation occurs with durene and the naphthalenes and has been analysed by comparison with theoretical curves leading to the calculation of enhancement coefficients.The results indicate that a small part of the reaction of naphthalene with nitronium ions under these conditions involves direct electron transfer between the reactants before the formation of the Wheland intermediate.The extent of this electron transfer is much greater than expected from Marcus theory calculations based on an outer-sphere electron transfer (ET) reaction: the discrepancy is discussed in terms of the initial interaction between the reactants and the solvent effects on the equilibrium constant for the electron transfer.
The proportionality constant is the rate constant for the particular unimolecular reaction. the reaction rate is directly proportional to the concentration of the reactant. I hope my blog about 1123-40-6 is helpful to your research. Safety of 4,4-Dimethylpiperidine-2,6-dione
Reference：
Piperidine – Wikipedia,
Piperidine | C5H6529N – PubChem