A near infrared and NMR spectroscopic study of the solvation of basic aprotic solvents and anions in tert-butanol

The near infrared (NIR) spectrum for pure tert-butanol shows an intense, ve ry narrow feature at 7062 cm(-1) which is close to the band for dilute solu tions in carbon tetrachloride and for the monomer in the gas phase. When ba sic aprotic solvents such as dimethylsulfoxide or cyanomethane are added, t he intensity of this (OH)(free) band falls to low values. Similar behaviour is observed for added tetraalkylammonium salts. These results are discusse d in terms of the scavenging of (OH)(free) groups by these additives. They are compared with results of similar studies using methanol and water and h ence estimates of the active solvation numbers are derived. NIR is also use d to help interpret H-1 NMR studies of the O-H protons in the systems.