Figure 8. Plot of gas phase basicities (GB) vs Hammett σ for pyridines

From

Comparison of Substituent Effects in Benzenes (XC5H5C), Pyridines (XC5H4N) and Phosphorines (XC5H4P) and their Protonated Species

R. Sanjeev, V. Jagannadham

World Journal of Chemical Education. 2020, 8(4), 155-162 doi:10.12691/wjce-8-4-3