Strain, physical organic models

One of the fundamental goals of physical organic chemistry has been to establish the limits of our models for structure and energetics. How long can a C-C bond be How much angle strain can a molecule tolerate How crowded can a structure be Such questions have defined many brilliant research efforts and have produced a fantastic array of bizarre and wonderful structures. Here we present a collection of representative highly-strained molecules, with an emphasis on the structural concepts that are being tested. 

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