Solubility Rules Derived from Binaryphase Diagrams

In the absence of temperature- or solvent-dependent polymorphism, the solubility rules that govern the behaviour of enantiomer mixtures on crystallization can be simply derived from the binary phase diagrams depicted in Figure 1. The component which can be obtained upon crystallization will be either the ra-cemic compound, or the enantiomer in excess, depending on the composition of the starting mixture with respect to the closest eutectic of the phase diagram. Thus, recrystallization of mixture M, having x = 0.8 (ee = 60%) can give the major enantiomer in pure form in cases (A) and (B). The maximum possible yield is given by NE/EA - 60% in case (A), and only 33% in case (B). In case (C), recrystallization of M can only afford the racemate in a maximum yield NE/RE. In this case the enantiomeric enrichment takes place in the liquid, but under equilibrium conditions the highest attainable purity is that of the eutec-tic. In other terms, in a partially resolved conglomerate, it is always possible to recover the major enan-tiomer in a yield equal to the ee of the starting material, whereas in a racemic compound the outcome of the crystallization will depend on the enantiomeric composition of the starting material and on that of eutectic; even in relatively favourable cases such as that depicted in Figure 1(B), the maximum possible yield will be lower than the ee of the starting material.

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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