The standard enthalpies of formation of some dibenzoannelated cycloalkanols

The heats of combustion of trans-9,10-bis-hydroxymethyl-9,10-dihydrophenanthrene, trans-5-hydroxymethyl-5,6-dihydro-7H-dibenzoa,c]cyclohepten-6-ol, 5-hydroxymethyl-5,6-dihydro-7H-di-benzoa,c]cycloheptene, 6-hydroxymethyl-5,6-dihydro-7H-dibenzoa,c]cycloheptene, 5H-dibenzo-a,d]cyclohepten-5-ol and 5H-10,11-dihydrodibenzoa,d]cyclohepten-5-ol were measured by means of a Gallenkamp adiabatic bomb calorimeter. Uncertainties in the determination of the heats of combustion ranged between 0.2 and 0.3%. The enthalpies of formation and atomization for the six compounds were derived. The experimental values of the heats of atomization were compared with those calculated using the Allen–Skinner bond energy scheme. Conclusions about energetic contributions which stabilize the structure of the investigated compounds were drawn.