Ruusuvuori, K. et al. published their research in Atmospheric Chemistry and Physics in 2013 | CAS: 644-98-4

2-Isopropylpyridine (cas: 644-98-4) belongs to pyridine derivatives. Pyridine has a dipole moment and a weaker resonant stabilization than benzene (resonance energy 117 kJ·mol−1 in pyridine vs. 150 kJ·mol−1 in benzene). Several pyridine derivatives play important roles in biological systems. While its biosynthesis is not fully understood, nicotinic acid (vitamin B3) occurs in some bacteria, fungi, and mammals.Product Details of 644-98-4

Proton affinities of candidates for positively charged ambient ions in boreal forests was written by Ruusuvuori, K.;Kurten, T.;Ortega, I. K.;Faust, J.;Vehkamaki, H.. And the article was included in Atmospheric Chemistry and Physics in 2013.Product Details of 644-98-4 This article mentions the following:

The optimized structures and proton affinities of a total of 81 nitrogen-containing bases, chosen based on field measurements of ambient pos. ions, were studied using the CBS-QB3 quantum chem. method. The results were compared to values given in the National Institute of Standards and Technol. (NIST) Chem. WebBook in cases where a value was listed. The computed values show good agreement with the values listed in NIST. Grouping the mols. based on their mol. formula, the largest calculated proton affinities for each group were also compared with exptl. observed ambient cation concentrations in a boreal forest. This comparison allows us to draw qual. conclusions about the relative ambient concentrations of different nitrogen-containing organic base mols. In the experiment, the researchers used many compounds, for example, 2-Isopropylpyridine (cas: 644-98-4Product Details of 644-98-4).

2-Isopropylpyridine (cas: 644-98-4) belongs to pyridine derivatives. Pyridine has a dipole moment and a weaker resonant stabilization than benzene (resonance energy 117 kJ·mol−1 in pyridine vs. 150 kJ·mol−1 in benzene). Several pyridine derivatives play important roles in biological systems. While its biosynthesis is not fully understood, nicotinic acid (vitamin B3) occurs in some bacteria, fungi, and mammals.Product Details of 644-98-4

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem