Vibrational spectroscopic studies of molecular associations by local anesthetics

Infrared spectroscopic studies have been performed on H-bonding for a number of local anesthetics: benzocaine, procaine, tetracaine, lidocaine, dibucaine, and three barbiturates: phenobarbital, pentobarbital, and thiopental. All these compounds have a marked tendency for self-association. When they are put into contact with systems containing H-bonds of the [Formula: see text], [Formula: see text], or [Formula: see text] types, however, the degree of self-association decreases and new H-bonds are formed at the expense of the former. The possible consequences of this for the chemical mechanism of anesthesia are briefly discussed.