Pivot atom

Cpd. No. No. Atoms Molecular Pivot Atom(s) Strand A Strand B MP or Yld. Refs. 

CH3CN, 33-11, 33 H20, 34, 35-jCH3CN, and 37jCH3CN represent nearly ideal or (more or less) distorted square pyramids, with the carbon atom Cl in the apical position. In most cases, the geometries of the Si-coordination polyhedra in the crystal are located on the Berry-pseudorotation coordinate (pivot atom Cl). 

Recently, Bogatsky et al.34) have reported the synthesis of cryptands incorporating urea moieties in which one of the urea nitrogens serve as a pivot atom. Cyclization of dianion 34 with diamine 18 afforded the macrocycle 35 in 21 % yield, which was converted into the corresponding oxo-cryptand 36 (Scheme 6). 

Carbodiimide, N-benzyl-AT-lithio-, 56, 210 Carbodiimides, o-styryl-, generation, electrocyclization, 57, 36 Carbodiimides, N-io-styryD-A -t/S-styryl)-, o-carbolines from, 57, 50 Carbodiimides, vinyl-, generation, uses in synthesis, 57, 36, 49 Carbolines, see entries under the appropriate Pyrido-indole names Carbon, as pivotal atom in... 

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