Department of Chemistry, University of Cyprus, P.O. Box 20537, 1678 Nicosia, Cyprus.
Chemistry. 2012 Jun 4;18(23):7109-16. doi: 10.1002/chem.201200248. Epub 2012 Apr 27.
X-ray studies show that 1,3-diphenyl-7-(thien-2-yl)-1,4-dihydro-1,2,4-benzotriazin-4-yl (6) adopts a distorted, slipped π-stacked structure of centrosymmetric dimers with alternate short and long interplanar distances (3.48 and 3.52 Å). Cyclic voltammograms of 7-(thien-2-yl)benzotriazin-4-yl 6 show two fully reversible waves that correspond to the -1/0 and 0/+1 processes. EPR and DFT studies on radical 6 indicate that the spin density is mainly delocalized over the triazinyl fragment. Magnetic susceptibility measurements show that radical 6 obeys Curie-Weiss behavior in the 5-300 K region with C=0.378 emu K mol(-1) and θ=+4.72 K, which is consistent with ferromagnetic interactions between S=1/2 radicals. Fitting the magnetic susceptibility revealed the behavior is consistent with an alternating ferromagnetic chain (g=2.0071, J(1) =+7.12 cm(-1), J(2) =+1.28 cm(-1)).
X 射线研究表明，1,3-二苯基-7-(噻吩-2-基)-1,4-二氢-1,2,4-苯并三嗪-4-基（6）采用具有交替短和长的面间距离（3.48 和 3.52 Å）的中心对称二聚体的扭曲的、滑移的π堆积结构。7-(噻吩-2-基)苯并三嗪-4-基 6 的循环伏安图显示出两个完全可逆的波，对应于-1/0 和 0/+1 过程。自由基 6 的 EPR 和 DFT 研究表明，自旋密度主要分布在三嗪片段上。磁化率测量表明，自由基 6 在 5-300 K 区域内遵循居里-外斯行为，C=0.378 emu K mol(-1)和θ=+4.72 K，这与 S=1/2 自由基之间的铁磁相互作用一致。拟合磁化率表明，该行为与交替铁磁链一致（g=2.0071，J(1) =+7.12 cm(-1)，J(2) =+1.28 cm(-1)）。
