π-Stacked structure of thiadiazolo-fused benzotriazinyl radical: Crystal structure and magnetic properties

• Published in: Chemical physics letters Vol. 626; pp. 11 - 14
• Main Authors: Miura, Youhei, Yoshioka, Naoki
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 17.04.2015
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/j.cplett.2015.03.009

•We newly prepared a thiadiazolo-fused benzotriazinyl radical (NSNBT).•NSNBT show characteristic bond alternation.•NSNBT exhibit very strong antiferromagnetic interaction derived from dimer structure. A novel benzotriazinyl radical with a 2,1,3-thiadiazolo fused ring (1,3-diphenyl-1,2-dihydro-[1,2,5]thiadiazolo[3′,4′:3,4]benzo[1,2-e]-1,2,4-triazine-2-yl; NSNBT) was prepared and characterized by ESR measurement, cyclic voltammetry, and X-ray crystallographic analysis. By a detailed study of bond lengths and angles, it was found that the molecular structure of NSNBT borrows characteristics both from 2,1,3-benzothiadiazole and from the unsubstituted benzotriazinyl radical, and the central phenyl ring presents a phenanthrene-type bond alternation. Molecules were shown to be arranged in a π-stacked columnar structure, with columns connected to each other through sulfur–sulfur interactions in the crystal. It exhibited strong antiferromagnetic interactions (J/kB=−434K) derived from its dimer structure.