摘要 : The enthalpies of hydrogenation of 2-cyclohexenone, 2-cyclohexenone, 2-methyl-3-isobutoxycyclohex-2-enone, and 5-methylhex-5-en-2-one have been measured and found to be -(97.1 +/- 2.7) kJ.mol(-1), -(109.2 +/- 2.9) kJ.mol(-1), -(10... 展开 The enthalpies of hydrogenation of 2-cyclohexenone, 2-cyclohexenone, 2-methyl-3-isobutoxycyclohex-2-enone, and 5-methylhex-5-en-2-one have been measured and found to be -(97.1 +/- 2.7) kJ.mol(-1), -(109.2 +/- 2.9) kJ.mol(-1), -(106.1 +/- 3.0) kJ.mol(-1), and -(113.2 +/- 2.7) kJ.mol(-1), respectively. In combination with the enthalpies of formation of the corresponding alkanones, we obtained the enthalpies of formation Delta(f)H(m)degrees (cyclopentenone) = -(100.3 +/- 3.0) kJ.mol(-1) and Delta(f)H(m)degrees(cyclohexenone) = -(121.9 +/- 3.0) kJ.mol(-1). By using isodesmic reactions, the resonance energy of cyclic enones is estimated to be (13 +/- 4) kJ.mol(-1). (C) 1998 Academic Press. [References: 30] 收起