The Planar Blatter Radical: Structural Chemistry of 1,4-Dihydrobenzo[e][1,2,4]triazin-4-yls.

Two planarized analogues of the prototypical Blatter radical (1), peri-annulated 1S and 1O , are demonstrated and provide a new platform for molecular and supramolecular engineering, and for tuning electronic and magnetic properties of the radical. Planarization of 1 results in bathochromic shift to the near-IR region, greater spin delocalization, and anodic shift of the reduction potential only for 1S . Magnetization studies revealed nearly ideal paramagnetic behavior at high temperatures for both radicals 1S and 1O with one-dimensional ferromagnetic interaction in the former (2J=14.4 cm(-1) ) and antiferromagnetic interactions in 1O at low temperatures.