Roth, H. J. et al. published their research in Archiv der Pharmazie und Berichte der Deutschen Pharmazeutischen Gesellschaft in 1966 | CAS: 1620-76-4

4-Methylpicolinonitrile (cas: 1620-76-4) 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.Electric Literature of C7H6N2

A colored pyridoinium borate complex was written by Roth, H. J.;Al Sarraj, S.. And the article was included in Archiv der Pharmazie und Berichte der Deutschen Pharmazeutischen Gesellschaft in 1966.Electric Literature of C7H6N2 This article mentions the following:

Boric acid reacts with 1,2-bis(N-methyl-4-pyridinium)glycol diiodide in basic solution to give a pyridoinium chelate which is oxidized by air to give I. I is red in the solid state and yellow in solution In the experiment, the researchers used many compounds, for example, 4-Methylpicolinonitrile (cas: 1620-76-4Electric Literature of C7H6N2).

4-Methylpicolinonitrile (cas: 1620-76-4) 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.Electric Literature of C7H6N2

Referemce:
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem