Photooxygenation of the Condensation Products of Naphthanthrone

Abstract

The structure of the polycyclic aromatic hydrocarbon with the absorption maximum at 567 nm, synthesized by the condensation of naphth- anthrone (NT), was deduced to be benzo[rs]dinaphtho[2, 1, 8, 7-klmn:2, 3, 4, 5, 6-vwxyz]hexaphene (BDH) by semi-empirical molecular orbital calculation methods. The photooxygenation of BDH and benzo[op]naphtho[2, 1, 8, 7-hijk]anthra[2, 1, 9, 8-stuva]-pentacene (BNAP) due to irradiate to light with each absorption maximum was investigated by measurering the absorption spectra and applying semi-empirical molecular orbital calculation methods. BNAP is synthesized by the same reaction process together with dibenzo[de:op]dinaphtho[2, 1, 8, 7-hijk : 2′, 1′, 8′, 7′-syuv]pentacene (DDP). BNAP and BDH do not undergo photooxygenation. On the other hand, DDP undergoes photooxygenation. The empirical results were illustrated in terms of difference in heat of reaction, which were 25.5 and 30.2 kJ/mol for BDH and BNAP, respectively. Their values are considerably larger than -3.1 kJ/mol of DDP. The difference in heat of formation seems to be the reason why BDH and BNAP does not undergo photooxygenation.

Key Words:

• photooxygenation
• endo-peroxide
• molecular orbital calculation
• benzo[op]naphtho[2, 1, 8, 7-hijk]anthra[2, 1, 9, 8-stuva]-pentacene
• benzo[rs]dinaphtho[2, 1, 8, 7-klmn:2, 3, 4, 5, 6-vwxyz]-hexaphene
• dibenzo[de:op]dinaphtho[2, 1, 8, 7-hijk : 2′, 1′, 8′, 7′-syuv]pentacene