Magnetostructural Investigation of Orthogonal 1‐Aryl‐3‐Phenyl‐1,4‐Dihydrobenzo[ e ][1,2,4]triazin‐4‐yl Derivatives

3‐Phenyl‐1,4‐dihydrobenzo[ e ][1,2,4]triazinyl radicals with the N(1) position substituted with naphth‐2‐yl ( 1 b ), naphth‐1‐yl ( 1 c ), pyren‐1‐yl ( 1 d ), anthracen‐9‐yl ( 1 e ), 2‐trifluoromethylphenyl ( 1 f ), 3‐trifluoromethylphenyl ( 1 g ), and 2‐iodophenyl ( 1 h ) were characterized by using single‐crystal X‐ray diffraction, variable‐temperature magnetic susceptibility, and DFT computational methods. The substituent at N(1) is essentially orthogonal to the heterocycle plane in 1 f and 1 h , and with a high torsion angle in 1 c and 1 d . Radicals 1 c and 1 h form unusual infinite chains with crisscrossing hetero‐co‐facial π–π interactions, whereas radical 1 d forms analogous homo‐co‐facial arrangements. Infinite chains of homo‐co‐facial π–π dimers are found in 1 b , 1 f and 1 g ; in the latter the position of the CF 3 group controls the slippage of the dimers in the chain. No π–π parallel arrangements were found in 1 e . Magnetic susceptibility measurements demonstrated strong antiferromagnetic interactions in 1 b ( J =−264±4 cm −1 ) and 1 f ( J =−134±1 cm −1 ), while weak intradimer ferromagnetic interactions were found in 1 g ( J 2 =+21±1 and J 1 =−15±1 cm −1 ). Other derivatives exhibit typical weak antiferromagnetic exchange interactions in a range of −5 to −10 cm −1 .