Loss of Solvent from a Molecular Crystal Solvate. Phenylazotribenzoylmethane Hemietherate

Abstract In a study(1) of the rearrangement in the solid state of phenylazotribenzoylmethane (I) it was discovered that this compound crystallizes from diethyl ether as an etherate (II) with the approximate composition (C6H5CO)3CN[dbnd]NC6H5 · ½[(C2H5)2O]; the ether was lost when the crystals stood for long periods at room temperature. Although many molecules of intermediate size crystallize with the incorporation of solvent molecules,(2) little is known about the loss of solvent from such solvates or the structure remaining after the solvent loss. Since the “de-etherated etherate” remaining after the loss of ether from II might show unusual chemical behavior an investigation of the structure of the etherate and the mechanism of loss of ether from single crystals has been undertaken.