pKaH of the Two Conjugate Acids (CH2N5+) and (HN6+) of Two Hypothetical Molecules the Pentazine (CHN5) and the Hexazine (N6) of Azabenzene Series: A Chemical Education Perspective

Extrapolation of a simple straight-line graph is used to calculate the p K aH of two cations (CH 2 N 5+ ) and (HN 6 + ) (eqn. 1 and 2) of two hypothetical molecules pentazine (CHN 5 ) and hexazine (N 6 ). This is achieved by simply an extrapolation of the locus of the plot of p K aH of protonated pyridine, pyridazines, s-triazine and 1,2,4,5-tetrazine versus the number of nitrogen atoms of the cyclic azines. Even well matched p K aH values for these two species were found from the extrapolation of the locus of the plot of p K aH versus average ionization potential (I v /eV) of the neutral azines. This article is useful in graduate research classroom to explain the acid-base properties and to determine the p K aH values.