Synlett 2008(13): 1931-1945  
DOI: 10.1055/s-2008-1078574
ACCOUNT
© Georg Thieme Verlag Stuttgart ˙ New York

Photochemistry of Nitrogen-Bridged Cyclophanes: 2,11-Diaza[32]anthracenoparacyclophane and 2,11-Diaza[32]paracyclophane Systems

Hideki Okamoto*a, Minoru Yamajib, Kyosuke Satakea
a Division of Chemistry and Biochemistry, The Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
Fax: +81(86)2517853; e-Mail: hokamoto@cc.okayama-u.ac.jp;
b Department of Chemistry and Chemical Biology, Graduate School of Engineering, Gunma University, Kiryu, Gunma 376-8515, Japan
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Publikationsverlauf

Received 3 April 2008
Publikationsdatum:
15. Juli 2008 (online)

Abstract

This account provides an overview of the photochemical properties of cyclophanes possessing nitrogen atoms in the bridge chains, namely 2,11-diaza[32]anthracenoparacyclophane and 2,11-diaza[32]paracyclophane systems. Although the photoreactions of aromatic molecules that are bound by a linker or fixed in a cyclophane structure have been widely investigated, much less attention has been paid to the photochemistry of aromatic rings incorporated in a nitrogen-bridged cyclophane. During the course of our work on the photoreactions of cyclophanes possessing nitrogen atoms in their bridge chains, the nitrogen-bridged cyclophanes were found to display photoproperties significantly different from those of the nonbridged aromatic chromophores or the corresponding carbon-bridged cyclophane analogues. The 2,11-diaza[32]anthracenoparacyclophane system displayed an efficient photochemical cycloaddition-adiabatic cycloreversion cycle in the excited singlet state, while in the triplet state, the photoisomer underwent a novel rearrangement and adiabatic cycloreversion. Upon photolysis of the 2,11-diaza[32]paracyclophane system, an octahedrane cage was formed. This is the first reported octahedrane formation to occur by the photochemical dimerization of benzene. Thus, the title cyclophane systems display a variety of photoprocesses involving cycloaddition, adiabatic cycloreversion accompanied by photoinduced chemiluminescence, novel rearrangements, and previously unknown benzene dimerization.

1 Introduction

2 Photochemistry of the 2,11-Diaza[32]anthracenoparacyclophane System

2.1 General Comments on the Photochemical Cycloaddition and Cycloreversion of Aromatic Molecules in the Singlet State

2.2 Intramolecular Photochemical Cycloaddition and Cyclo­reversion of the 2,11-Diaza[32]anthracenoparacyclophane System

2.3 General Introduction to the Photochemistry of Aromatic Molecules in the Triplet State

2.4 Photoproperties of the 2,11-Diaza[32]anthracenoparacyclophane System in the Triplet State

3 Photochemistry of the 2,11-Diaza[32]paracyclophane System

3.1 General Remarks on the Photoreactions of Cyclophanes Containing Two Benzene Rings

3.2 Construction of the 2,11-Diaza[32]paracyclophane Skeleton

3.3 Photoreactions of the 2,11-Diaza[32]paracyclophane System

4 Summary

35

Okamoto, H.; Yamaji, M.; Satake, K. unpublished results.