Marcus has published his theory in 1956. For long years there was an intensive search for the inverted region which would be a proof of the theory. But all experiments with series of reactions of more and more negative G0 revealed only an increase of the reaction rate up to the diffusion limit, i.e. to a value indicating that every encounter lead to electron transfer, and that limit held also for very negative G0 values (Rehm-Weller behaviour). It took about 30 years until the inverted region was unequivocally substantiated by Miller, Calcaterra and Closs for an intermolecular electron transfer in a molecule where donor and acceptor are kept at a constant distance by means of a stiff spacer (Fig.4).
A posteriori one may presume that in the systems where the reaction partners may diffuse freely the optimum distance for the electron jump may be sought, i.e. the distance for which G‡ = 0 and G0 = - o. For o is dependent on R, o increases for larger R and the opening of the parabola smaller. It is formally always possible to close the parabola in Fig. 2 to such an extent, that the f-parabola intersects the i-parabola in the apex. Then always G‡ = 0 and the rate k reaches the maximum diffusional value for all very negative G0. There are, however, other concepts for the phenomenon, e.g. the participation of excited states or that the decrease of the rate constants would be so far in the inverted region that it escapes measurement.
R.A. Marcus and his coworkers have further developed the theory outlined here in several aspects. They have included inter alia statistical aspects and quantum effects, they have applied the theory to chemiluminescence and electrode reactions. R.A Marcus received the Nobel Prize in Chemistry in 1992, his Nobel Lecture gives an extensive view of his work.
Read more about this topic: Marcus Theory
Other articles related to "experimental results, results, experimental, result":
... presented his treatise in the form of mathematical demonstrations without reference to experimental results ... of mathematics in obtaining scientific results was far from obvious ... Galileo was realistic about the acceptability of presenting experimental results as evidence or because he himself had doubts about the epistemological status of experimental ...
... The recurring and surprising result is that while experimental subjects have clear difficulties with the subtle strategic calculations that the theory takes into account, the ... The result is that voting outcomes and thus payoffs mimic closely the predictions of the theory ... Granting one of the players some limited agenda power does not change the results ...
Famous quotes containing the words results and/or experimental:
“Intellectual despair results in neither weakness nor dreams, but in violence.... It is only a matter of knowing how to give vent to ones rage; whether one only wants to wander like madmen around prisons, or whether one wants to overturn them.”
—Georges Bataille (18971962)
“If we take in our hand any volume; of divinity or school metaphysics, for instance; let us ask, Does it contain any abstract reasoning concerning quantity or number? No. Does it contain any experimental reasoning, concerning matter of fact and existence? No. Commit it then to flames: for it can contain nothing but sophistry and illusion.”
—David Hume (17111776)