Thermochemistry of Amines: Experimental Standard Molar Enthalpies of Formation of N-Alkylated Piperidines

摘要: The standard molar enthalpies of formation Δ f H m ° (l) at the temperature T = 298.15 K were determined using combustion calorimetry for N-methylpiperidine (A), N-ethylpiperidine (B), N-propylpiperidine (C), N-butylpiperidine (D), N-cyclopentylpiperidine (E), N-cyclohexylpiperidine (F), and N-phenylpiperidine (G). vaporization l g these compounds obtained from variation vapor pressure measured in a flow system. From data following gaseous phase (g) derived for: A −(61.39 ± 0.88); B −(88.1 1.3); C −(105.81 0.66); D −(126.2 E ( −88.21 0.75); F −(135.21 0.94); G (70.3 1.4) kJ · mol−1. They are used to determine strain cyclic amines A–G. N-alkylated piperidine rings have been found be about strainless.