Akira IZUOKA,* Tomohide MURASE,* Mitsuyoshi TSUKADA,* Yuko ITO,* Tadashi SUGAWARA,* Akira UCHIDA,** Naoki SATO*** and Hiroo INOKUCHI (*Univ. of Tokyo, **Toho Univ., ***Kyoto Univ.)
[Tetrahedron Lett. 38, 245 (1997)]
Crystal structure of an endoperoxide of tetrabenzo[de,hi,op,st]pentacene (TBPA-O2) was accurately determined by X-ray crystallography (see Figure 1). The unusually long O-O and C-O bonds was rationalized by the characteristics molecular structure of TBPA-O2. The thermodynamical behavior of addition of oxygen to TBPA and elimination of oxygen from TBPA-O2 was discussed based on the enthalpy difference between TBPA-O2 and TBPA + O2 and the thermodynamic parameters of the extrusion reaction of oxygen from TBPA-O2.
Figure 1. a) TBPA-O2 and b) its molecular structure.