Preparation, Structure Determination, and Electrochemical Properties of 4,5-Dialkylbenzo1,2-d:4,5-d'bis1,2,3triselenoles and Their Singlet and Triplet-State Dications

摘要

4,8-Dialkylbenzo1,2-d:4,5-d'bis1,2,3triselenoles alkyl=Et, Bu, and Oc (C8H17) were first prepared and treated with concentrated sulfuric acid-d(2) to generate benzobistriselenole dications, which were determined by NMR spectroscopy. The oxidation of dioctylbenzobistriselenole with three equivalents of single-electron oxidizing reagent (NOSbF6) produced the corresponding dication(.)2SbF(6)(-), and the salt was isolated into a stable form. The ESR spectra of the dications measured in concentrated sulfuric acid in the range of room temperature and -196 degrees C were observed as split peaks similar to that of solid state dication(.)2SbF(6)(-). Magnetic susceptibility of the dication(.)2SbF(6)(-) was determined by a superconducting quantum interference device (SQUID) magnetometer, which showed the salt is diamagnetic. The optimized structures and the total energy of the singlet- and triplet-state benzobistriselenole dications were calculated using the density functional theory (DFT) method at the B3LYP6-311G**(d,p) level. The results revealed that the structures of the singlet- and triplet-state dications calculated have a completely planar forms and the triplet-state dication is slightly more stable than the singlet-state one in acetonitrile using a polarizable continuum model (PCM).