Tetrazines and tetraphosphorins, tetrazoles and tetraphospholes: a density functional theory study

Density functional calculations are reported on pyridine and the three isomeric diazines; 1,2,4,5-tetrazine; some tetrazoles (1H- and 2H-parent and related carbene derivatives); and their corresponding valence isoelectronic phosphorus counterparts, phosphorin, the diphosphorins, 1,2,4,5-tetraphosphorin and tetraphospholes. Using these quantum chemically derived numbers, thermochemical comparisons between related nitrogen and phosphorus containing species are made. Comparison is also made to the admittedly sparse experimental literature.