Thermodynamic measurements for the Diels-Alder adduct of anthracene and maleic anhydride

Abstract

In the present experimental work, the energy of combustion of the crystalline Diels-Alder adduct of anthracene and maleic anhydride: C 18 H 12 O 3 , was measured with a model 1241 Parr automatic calorimeter and a Parr model 1710 calorimeter controller. The standard molar enthalpy of combustion of the (anthracene + maleic anhydride) adduct at p o = 0.1 MPa was determined to be Δ c H m o (C 18 H 12 O 3 , cr, 298.15 K) = −(8380.0±5.9) kJ·mol −1 . The molar enthalpy of fusion of this adduct at its melting temperature (534.07 K), as measured by a 910 DuPont d.s.c. and a 9900 DuPont thermal (analyzer + digital computer), was found to be (36.3±4.2) kJ·mol −1 . The other thermodynamic properties of the (anthracene + maleic anhydride) adduct derived from those measured properties are: Δ f H m o (C 18 H 12 O 3 , cr, 298.15 K) = −(418.2±6.4) kJ·mol −1 and Δ f H m o (C 18 H 12 O 3 , 1, 298.15 K) = −(389.7 ± 7.7) kJ·mol −1 .