Beta-quinol : an Example of the Firm Union of Molecules Without the Formation of Chemical Bonds Between Them

Abstract

THE substance formerly called 'β-‘quinol and obtained by crystallization of quinol from methanol has been shown¹ to be a compound of three molecules of quinol with one molecule of methanol. It is one of a series of solid compounds of very similar crystalline structure², which consists of two interpenetrating giant molecules of hydrogen-bonded quinol units together enclosing small molecules, such as that of methanol, in cavities that are left when these two giant molecules are fitted together as closely as possible. Compounds of this general type in which one component imprisons the other without necessarily having any strong attractive interaction with it have been named clathrate compounds³. When crystallized, for example, from ethanol in conditions such that molecules of suitable size are not available for enclosure in this way, quinol forms a more densely packed structure, α-quinol, by a different arrangement of quinol units which has not yet been completely determined.