title: Operation of long-range substituent effects in rigid opiates: protonated and unprotonated oxymorphone.
abstract: The structure of protonated oxymorphone (amine salt) was determined by an X-ray crystallographic study. Significant differences were found with the previously determined structure of unprotonated oxymorphone (free base). Upon protonation on nitrogen, an elongation of the N-C bound occurred, accompanied by subtle changes in bond lengths and angles distant from the site of protonation. These changes in geometry are interpreted as a reflection of long-range substituent effects.
mesh_terms: D002626:Chemistry, Pharmaceutical; D004091:Hydromorphone / Q000031:analogs & derivatives; D008968:Molecular Conformation; D009294:Narcotics; D010111:Oxymorphone; D011522:Protons; D014961:X-Ray Diffraction
chemical_list: D009294:Narcotics; D011522:Protons; D010111:Oxymorphone; D004091:Hydromorphone