Toward an Organometallic Molecular Brake with a Metal Foot Pedal:Synthesis,Dynamic Behavior,and X-ray Crystal Structure of [(9-Indenyl)triptycene]chromium Tricarbonyl

摘要

The potential use of haptotropic shifts to control rotational barriers has been initiated by the synthesis of (9-indenyl)triptycene (12) and its chromium tricarbonyl derivative (13).Both complexes have been characterized by X-ray crystallography and variable-temperature NMR spectroscopy,revealing barriers to rotation of 12 and 13 kcal mol~(-1),respectively.In the metal complex,the chromium carbonyl moiety coordinates to one of the blades of the triptycene unit rather than to the more crowded indenyl group.