| Popis: |
In order to understand the antiaromaticity of maleimides, the enthalpies of formation and sublimation of N-methylmaleimide, N-methylsuccinimide, N-methylphthalimide, and N-benzoyl-N-methylbenzamide were measured. The numerical values of enthalpies of formation for these compounds in the solid state are −329.3 ± 1.4, −469.8 ± 1.6, −325.0 ± 2.1, and −239.6 ± 3.8 kJ mol-1, respectively, while the corresponding values in the gaseous state are −256.0 ± 1.5, −389.7 ± 1.6, −233.9 ± 2.2, and −119.5 ± 3.8 kJ mol-1, respectively. The values of enthalpies of sublimation for the same compounds are 73.3 ± 0.5, 80.1 ± 0.3, 91.1 ± 0.5, and 120.1 ± 0.4 kJ mol-1, respectively. We find that the antiaromaticity of maleimides is only modest. |
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