THERMOCHEMISTRY OF PHENOLS - EXPERIMENTAL STANDARD MOLAR ENTHALPIES OF FORMATION OF 2-PHENYLPHENOL, 4-PHENYLPHENOL, 2,6-DIPHENYLPHENOL, AND2,2'-DIHYDROXYBIPHENYL AND 4,4'-DIHYDROXYBIPHENYL

The standard (p degrees = 0.1 MPa) molar enthalpies of formation Delta (f)H(m) degrees(cr) at the temperature T = 298.15 K were measured by u sing combustion calorimetry of 2-phenylphenol, 4-phenylphenol, 2,6-dip henylphenol, 2,2'-dihydroxybiphenyl, and 4,4'-dihydroxybiphenyl. The s tandard molar enthalpies of sublimation Delta(cr)(g)H(m) degrees of th e compounds were obtained from the temperature variation of the vapour pressure measured in a flow system. Molar enthalpies of fusion Delta( cr)(1)H(m) degrees of the compounds were measured by d.s.c. Values of the weak interactions (about 2kJ.mol(-1) to 4kJ.mol(-1)) of phenyl sub stituents with the hydroxyl group were derived from the enthalpies of formation in the gas phase. [GRAPHICS] (C) 1998 Academic Press Limited .