Ring strain analysis

Compared to 1,4-butanediol, which forms tetrahydrofuran byproduct in PBT polymerization, PDO is difficult to cyclize into oxetane because of the high ring strain. Oxetane was not found in the byproduct analysis [23],... 

Further support for the rehybridization model was provided by analysis of the spin densities of annelated 1,4-naphthoquinones, n hthalenes, and cyclobutaben-zene radical anions by ESR. The hyperfine coupling constants at the methylene position decrease as ring strain increases. Calculation of spin densities using the rehybridization model leads to an excellent fit of experimental spin densities, while calculation of spin densities using either the Coulson-Crawford hyperconjugation model or INDO do not accurately correlate experimental values. Such results suggest that rehybridization can account for the observed changes in spin densities. 

A. Analysis of Ring Strain in Terms of Atomic Energies. 74... 

The high-frequency shifts in the CO and CH stretching vibrations of cyclopropanones are related to ring strain and occur to a lesser extent in cyclobutanone. Although normal coordinate analysis has been employed in predicting these shifts, the theoretical models do not appear to be completely reliable.6 ) An important factor causing the above shifts... 

Analysis of the infrared spectrum of l16 21 showed an antisymmetric S02 frequency somewhat higher than in linear sulfonamides, probably due to ring strain.16 IR spectra of metal salts of 1 in solution have also been studied.22... 

Conformation and Conformational Analysis Conformation of Ethane Conformation of Propane Conformation of Butane Eclipsed and Staggered Eorms Ring Strains in Cycloalkanes Principles of Conformation 165... 

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