Synlett 2007(6): 0851-0869  
DOI: 10.1055/s-2007-973887
ACCOUNT
© Georg Thieme Verlag Stuttgart · New York

Dynamic Redox Systems as Electrochromic Materials: Bistability and Advanced Response

Takanori Suzuki*a, Eisuke Ohtaa, Hidetoshi Kawaia, Kenshu Fujiwaraa, Takanori Fukushimab
a Division of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
b ERATO-SORST, Aida Nanospace Project, 2-41, Aomi, Koto-ku, Tokyo 135-0064, Japan
Fax: +81(11)7062714; e-Mail: tak@sci.hokudai.ac.jp;
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Publikationsverlauf

Received 9 August 2006
Publikationsdatum:
26. März 2007 (online)

Abstract

‘Dynamic redox systems’ is the name given to a certain class of compounds that can be reversibly converted into the corresponding charged species accompanied by C-C bond formation/cleavage upon electron transfer. This account details the two major motifs (hexaphenylethane derivatives and butane-1,4-diyl dications) that have been developed in the principal author’s group.

1 Introduction

2 Dynamic Redox Properties

2.1 Dications Twisted by 90°

2.2 Intramolecular Redox Switching of Single Bonds

3 Electrochromism Based on the Dynamic Redox Properties of Hexaphenylethane Derivatives

3.1 Tetraaryldihydrophenanthrenes: Prototype endo Systems

3.2 Electrochiroptical Response System Based on the HPE Skeleton

3.3 Redox Switching for Fluorescence Based on the HPE ­Skeleton

3.4 Further Advanced Molecular Response System Based on the HPE Skeleton

3.5 HPE-Type Redox System with Another Arylene Spacer

4 Electrochromism Based on the Dynamic Redox Properties of Butane-1,4-diyl Dications

4.1 1,1,2,3,4,4-Hexaarylbutane-1,4-diyl Dications: The Prototype exo System

4.2 Electrochiroptical Response Systems Based on the Butane-1,4-diyl Dication

4.3 Reversible Oligomerization to Oligo(butane-1,4-diyl ­Dicationic) Species

5 Future Outlook

24

X-ray analysis on the dication salt of tetrakis(4-methoxy-phenyl)ethylene showed the twisting angle of 62° for the mixed counter-anion salt containing SbCl6 - and Cl- (ref. 25). PM3 calculation of tetrakis(4-dimethylaminophenyl)eth-ylene predicted twisting of 80.6° for the dication (ref. 26).

47

By incorporation of two different diarylmethylium chromophores the reduction of dication 9 proceeds stepwise, thus allowing generation and detection of the bond-dissociated cation radical by steady-state spectroscopy (ref. 46).

53

The binaphthylic dication with 4-Me2NC6H5 groups was also prepared which gave [5]helicene-type donor upon reduction. Further studies were carried out for xanthene and thioxanthene derivatives 10a,b/10a,b 2+ because difficulties were encountered when conducting their optical resolution.

66

Suzuki, T.; Ohta, K.; Nehira, T.; Kawai, H.; Fujiwara, K. Abstracts of Papers, 18th Symposium on Fundamental Organic Chemistry, Oct. 7-9, 2006, Fukuoka.

72

Kawai, H.; Takeda, T.; Fujiwara, K.; Suzuki, T. Abstracts of Papers, 18th Symposium on Fundamental Organic Chemistry, Oct. 7-9, 2006, Fukuoka.

83

Ohta, E.; Kawai, H.; Fujiwara, K.; Suzuki, T. Abstracts of Papers, 18th Symposium on Fundamental Organic Chemistry, Oct. 7-9, 2006, Fukuoka.

85

Higuchi, H.; Kawai, H.; Fujiwara, K.; Suzuki, T. Abstracts of Papers, Pacifichem, Dec 15-20, 2005, Honolulu, 906.