## 2 Materials and Methods
### Vaporization Thermodynamics of Alkyl-Quinolines and Alkyl-Pyridines

Table 2: Compilation of enthalpies of vaporization, \(\Delta_{1}^{\mathbf{S}}H_{\mathbf{m}}^{\mathbf{O}}\), for the quinoline derivatives. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Compound** & **M a** & **T-Range** & \(\Delta_{1}^{\mathbf{g}}\)**H\({}_{\mathbf{m}}^{\mathbf{o}}\) (\(T_{\mathbf{AV}}\))** & \(\Delta_{1}^{\mathbf{g}}\)**H\({}_{\mathbf{m}}^{\mathbf{o}}\) (298.15 K) b** & **Ref.** \\ \hline
**CAS** & & **K** & **kJ\(\cdot\)mol\({}^{-1}\)** & **kJ\(\cdot\)mol\({}^{-1}\)** & \\ \hline pyridine [110-86-1] & & & & \(40.2\pm 0.2\) & [21] \\
2-methyl-pyridine [109-06-8] & & & & \(42.5\pm 0.2\) & [21] \\
3-methyl-pyridine [108-99-6] & & & & \(44.6\pm 0.2\) & [21] \\
4-methyl-pyridine [108-89-4] & & & & \(44.8\pm 0.2\) & [21] \\ \hline
2-ethyl-pyridine & E & 323–373 & \(42.9\pm 0.2\) & \(45.9\pm 0.4\) & [22] \\
100-71-0 & CC & 363 & \(54.1\pm 1.0\) & \(44.7\pm 1.0\) & [23] \\  & SF & 312–422 & \(40.7\pm 1.7\) & \(44.6\pm 1.8\) & Table S4 \\  & \(J_{x}\) & & & \(46.2\pm 1.0\) & Table 5 \\  & \(T_{b}\) & & & \(46.0\pm 1.5\) & Table 8 \\  & & & & \(45.9\pm 0.4\) c & average \\ \hline
3-ethyl-pyridine & E & 334–373 & \(44.3\pm 0.4\) & \(47.6\pm 0.6\) & [22] \\
536-78-7 & SF & 349–438 & \(43.2\pm 1.4\) & \(49.0\pm 1.5\) & Table S4 \\  & \(J_{x}\) & & & \(48.5\pm 1.0\) & Table 5 \\  & \(T_{b}\) & & & \(48.6\pm 1.5\) & Table 8 \\  & & & & \(48.0\pm 0.5\) c & average \\ \hline
4-ethyl-pyridine & E & 334–372 & \(45.1\pm 0.4\) & \(48.4\pm 0.6\) & [22] \\
536-75-4 & n/a & 333–442 & \(42.9\pm 1.5\) & \(48.3\pm 1.6\) & [12] \\  & T & 284.5–352.8 & \(47.4\pm 0.6\) & \(48.5\pm 0.7\) & [24] \\  & C & 363 & \(55.7\pm 2.2\) & \(46.3\pm 2.9\) & [23] \\  & \(J_{x}\) & & & \(49.6\pm 1.0\) & Table 5 \\  & \(T_{b}\) & & & \(49.3\pm 1.5\) & Table 8 \\  & & & & \(48.6\pm 0.4\) c & average \\ \hline
2-methyl-5-ethyl-pyridine & E & 325.1–449.8 & \(46.5\pm 1.0\) & \(52.5\pm 1.1\) & [25] \\
104-90-5 & T & 252.8–275.9 & \(51.4\pm 1.4\) & \(49.0\pm 1.5\) & [16] \\  & n/a & 348–451 & \(44.7\pm 1.0\) & \(51.5\pm 1.1\) & [12] \\  & n/a & & & (46.3 \pm 0.4) & [26] \\  & SF & 332–451 & \(45.6\pm 1.0\) & \(51.8\pm 1.1\) & Table S4 \\  & \(J_{x}\) & & & \(52.0\pm 1.0\) & Table 5 \\  & \(T_{b}\) & & & \(51.5\pm 0.6\) c & average \\ \hline
2-n-propyl-pyridine & E & 339.1–372.8 & \(46.3\pm 0.4\) & \(50.2\pm 0.6\) & [22] \\
622-39-9 & n/a & 338–445 & \(43.1\pm 1.0\) & \(49.5\pm 1.1\) & [12] \\  & SF & 324–446 & \(44.4\pm 1.2\) & \(50.0\pm 1.3\) & Table S4 \\  & \(J_{x}\) & & & \(51.2\pm 1.0\) & Table 5 \\  & \(T_{b}\) & & & \(49.7\pm 1.5\) & Table 8 \\  & & & & \(50.2\pm 0.4\) c & average \\ \hline
3-n-propyl-pyridine & E & 350.2–371.7 & \(49.6\pm 0.4\) & \(53.9\pm 0.7\) & [22] \\
4673-31-8 & n/a & 350–450 & \(43.1\pm 1.0\) & (\(58.5\pm 1.1\)) & [12] \\  & SF & 348–459 & \(46.8\pm 1.0\) & \(53.8\pm 1.1\) & Table S4 \\  & \(J_{x}\) & & & \(52.4\pm 1.0\) & Table 5 \\  & \(T_{b}\) & & & \(51.8\pm 1.5\) & Table 8 \\  & & & & \(53.3\pm 0.5\) c & average \\ \hline
4-n-propyl-pyridine & E & 354.6–374.4 & \(48.4\pm 1.2\) & \(53.0\pm 1.4\) & [22] \\
4673-31-8 & n/a & 354–465 & \(44.2\pm 1.0\) & \(51.8\pm 1.2\) & [12] \\  & T & 294.1–374.1 & \(50.5\pm 0.2\) & \(52.7\pm 0.3\) & [24] \\  & SF & 352–464 & \(45.8\pm 1.0\) & \(52.9\pm 1.2\) & Table S4 \\  & \(J_{x}\) & & & \(53.4\pm 1.0\) & Table 5 \\  & \(T_{b}\) & & & \(52.6\pm 1.5\) & Table 8 \\  & & & & \(52.7\pm 0.3\) c & average \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Compilation of enthalpies of vaporization, \(\Delta_{1}^{\mathbf{g}}\)H\({}_{\mathbf{m}}^{\mathbf{o}}\), for the pyridine derivatives. A quick look at columns 5 in Tables 2 and 3 shows a remarkable consistency of the \(\Delta_{1}^{\rm g}H_{\rm m}^{\rm o}(298.15\) K)-values for most of the alkyl-substituted quinolines and pyridines listed in the tables. It should be noted, however, that such a systematic treatment of the available vapor pressures of quinolines and pyridines towards vaporization enthalpies was carried out for the first time.