Chemical topology topological isomers

Let us consider another way of connecting molecules without chemical bond formation. If through a macrocy-clic molecule passes a linear one with bulky terminal groups, the system thus obtained represents a topological isomer of the type dumbbell in a ring (Fig. 31 ). Such... 

The two topological isomers A and B of interconnected rings (reproduced with permission from reference , copyright 1961, American Chemical Society). 

In a very recent review of Met-Cars and other metal carbon clusters (246), the authors concluded If experimentalists and theoreticians presently agree to consider that the form with Td symmetry represents the most abundant isomer of Ti8C12 and other Met-Cars, it is mainly because the topological, physical, and chemical properties specific to that cluster shape explain or agree with the experimental information presently available. 

The topologically defined region(s) on an enzyme responsible for the binding of substrate(s), coenzymes, metal ions, and protons that directly participate in the chemical transformation catalyzed by an enzyme, ribo-zyme, or catalytic antibody. Active sites need not be part of the same protein subunit, and covalently bound intermediates may interact with several regions on different subunits of a multisubunit enzyme complex. See Lambda (A) Isomers of Metal Ion-Nucleotide Complexes Lock and Key Model of Enzyme Action Low-Barrier Hydrogen Bonds Role in Catalysis Yaga-Ozav /a Plot Yonetani-Theorell Plot Induced-Fit Model Allosteric Interaction... 

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