Heat of reaction and reaction volume for the formation of ethers from diazo compounds in methanol

The heat of reaction and reaction volume for formation of ethers from several diazo compounds with two phenyl groups in methanol were determined by the transient grating and photoacoustic methods. It was found that the reaction volume significantly contributes to the photothermal signal and that the reaction volume is sensitive to the molecular structure of the diphenyl groups. The reaction volume is as large as 51 ml/mol for the creation of diphenylmethyl methyl ether. This large volume change is interpreted in terms of the rearrangement of phenyl groups by the reaction. The partial molar volume of N2 and diffusion constants of N2 and diazo compounds are determined simultaneously.