Infrared and Raman studies of hydrogen bonded complexes involving acetone, acetophenone and benzophenone—I. Thermodynamic constants and frequency shifts of the νOH and νCO stretching vibrations

✍ Scribed by R. Thijs; Th. Zeegers-Huyskens

• Publisher: Elsevier Science
• Year: 1984
• Tongue: English
• Weight: 544 KB
• Volume: 40
• Category: Article
• ISSN: 1386-1425
• DOI: 10.1016/0584-8539(84)80054-9

✦ Synopsis

The hydrogen bonded complexes between phenol derivatives and acetone (I), acetophenone (II) and benzophenone (III) have been studied in carbon tetrachloride solution by i.r. spectroscopy. The formation constants, the enthalpies of complex formation, the AvoH and A+-values have been determined. For a given phenol derivative, the thermodynamic constants and AvOH are ordered according to 1 > II > III and the influence of a substituent implanted on the phenolic ring can be expressed by the Hammett relationship. The p coefficients of the Hammett equation are related to the complexation enthalpies. The Badger-Batter relation is valid for the three bases. The comparison with complexes involving other carbonyl bases allows to precise the influence of the substituent implanted on the carbonyl group. The AvoH values obey the dual substituent parameter equation using u, and ai; the p,/pR ratio is higher than one. The AvcXO values are shown to depend on the complexation enthalpy and on the delocalixation effect of the substituents.