Albery-More O’Ferrall-Jencks diagram

Reaction hypercube A generalization of the Albery-More O Ferrall-Jencks diagram to n dimensions. The two-dimensional case is a square, the three-dimensional case is a cube, and so on. For any reaction h3fpercube energy could be included as an additional dimension orthogonal to the others but this is difficult to draw except in the two-reaction-dimension case... 

Energy surfaces of this type appear to have been described first by Hughes et al. in 1936. Their current popularity and utility are a consequence of developments by Albery, More O Ferrall, and Jencks, and they are sometimes called More O Ferrall plots or More O Ferrall-Jencks plots. We will refer to them as RIP diagrams, this designation arising from the symbolism in Fig. 5-19. 

In Figure 7.21 we show projections of the surfaces in Figure 7.20 of the sort we just described both axes represent an individual reaction coordinate. In other words, these are what one would see if the surfaces of Figure 7.20 were viewed directly from the top with no topographical features included. The diagonal lines represent the Sn2 reaction paths, and the positions of the transition states are marked with a heavy dot. These two-dimensional projections are known as More O Ferrall-Jencks plots (also known as More O Ferrall plots, or More O Ferrall-Albery-Jencks plots). As substitution on the alkyl group increases, the Sn2 reaction paths develop more curvature, and the transition state moves toward the carbo-cation quadrant of the plot. Each solid line (linear and curved) in these diagrams would be... 

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