A series of 3-substituted 1-phenyl-1,4-dihydrobenzo[e][1,2,4]triazin-4-yls 1 was prepared by addition of PhLi to 3-substituted benzo[e][1,2,4]triazines 2 followed by aerial oxidation. The scope of the C(3) substituents in the reaction was investigated, and 10 structurally diverse radicals 1 were isolated, their stability was assessed and properties were investigated with spectroscopic and electrochemical methods. Two radicals were analyzed with single-crystal XRD methods. Experimental data are compared to DFT results and correlated with Hammett substituent parameters.