View : 33 Download: 0

Facile reduction of zeolite-encapsulated viologens with solvated electrons and selective dispersion of inter- and intramolecular dimers of propylene-bridged bisviologen radical cation

Title
Facile reduction of zeolite-encapsulated viologens with solvated electrons and selective dispersion of inter- and intramolecular dimers of propylene-bridged bisviologen radical cation
Authors
Park, YSLee, KLee, CYoon, EB
Ewha Authors
이종목
SCOPUS Author ID
이종목scopus
Issue Date
2000
Journal Title
LANGMUIR
ISSN
0743-7463JCR Link
Citation
vol. 16, no. 10, pp. 4470 - 4477
Publisher
AMER CHEMICAL SOC
Indexed
SCI; SCIE; SCOPUS WOS
Abstract
Zeolite-Y (Y), zeolite-L (L), mordenite (M), and ZSM-5 exchanged with methyl viologen C(1)VC(1)(2+) and N',N "-trimethylenebis( 1-methyl-4,4'-bipyridinium) thenceforth bisviologen) C(1)V(2+)-C(3)-VC(1)(2+) were prepared. Treatment of the dried, viologen-doped zeolites with solvated electrons in diethyl ether readily yields the corresponding viologen radical cation, i.e., C(1)VC(1)(.+) and C(1)V(.+)-C(3)-VC(1)(.+) within the zeolite pores. Although C(1)V(.+)-C(3)-VC1(.+) readily folds to its intramolecular dimer C(3)[C(1)V(.+)](2) in solution, it remains in the open form in the four zeolites. C(1)VC(1)(.+) readily dimerizes to [C(1)VC(1)(.+)](2) at high concentrations in L but not; in other zeolites. However, C(1)V(.+)-C(3)-VC(1)(.+) does not dimerize by itself in any of the four zeolites even at high concentrations. C(1)VC(1)(.+) readily dimerizes in Y, L, and M when the pores are filled with water. The hydration-induced dimerization also works well for C(1)V(.+)-C(3)-VC(1)(.+) in L and M. This leads to selective formation of the unprecedented intermolecular dimer of bisviologen radical cation, i.e., [C(1)V(.+)-C(3)-VC(1)(.+)](2) in L and M. The intramolecular analogue C(3)[C(1)V(.+)](2) can also be dispersed into Y, L, and M by direct occlusion of its bisperchlorate salt from the acetonitrile solution. The broad similar to 530 nm band of the viologen radical dimer splits into two when the viologen radical moieties are forced to juxtapose in the collinear conformation within the narrow and straight channels oft and M. The near infrared band of the viologen radical dimer Progressively blue shifts with decreasing the interannular distance. This paper thus demonstrates a novel use of zeolites to selectively disperse inter- and intramolecular dimers of diradical dication and to lock the viologen radical dimers into the collinear conformation which allows us to delineate the spectral variation of viologen radical dimers with changing the interannular conformation and distance.
DOI
10.1021/la991430+
Appears in Collections:
자연과학대학 > 화학·나노과학전공 > Journal papers
Files in This Item:
There are no files associated with this item.
Export
RIS (EndNote)
XLS (Excel)
XML


qrcode

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

BROWSE