Solvent-Dependent C-N Bond Lengths in a Protonated Orthoamide

摘要

In the early 1970s a new kind of isomerism. in which two isomers differ only in their bond lengths, was proposed by Chatt et al. based on X-ray structure analyses on transition metal complexes, and by Hoffmann et al. based on theoretical studies. The"bond stretch isomers" established to date by crvstallography have been critically reviewed by Parkin.'31 and errors were found in most (if not all) interpretations of the X-ray data. This failure to conclusively prove bond stretch isomerism in these complexes, east doubts on the existence of this type of isomerism.