Stile, Martyn Allen (1987) An investigation into the synthesis of conjugated bipyridinium-containing polymers. PhD thesis, University of Warwick.

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Abstract

1,1'-dimethy1-4,4 1 -bipyridinium dication (methyl viologen) can be
reversibly reduced to a blue radical cation, either electrically or
photochemically. Other alkyl viologens behave similarly, but aryl
viologens are more easily reduced, and this trend increases with the
electron-withdrawing capability of the substituents.
Polymers containing viologens have been made and shown to give a
permanent blue colouration when irradiated, but the viologen units were
always isolated electronically.
The present work describes attempts made to produce polymers containing
viologens linked by wholly conjugated chains, either from the 1- (N-)
or 2- positions of the bipyridyl. The only polymer produced was made by
the condensation of 2,2'-dimethy1-4,4'-bipyridyl with 1,4-
diformylbenzene, and contained viologen units linked by "styryl" groups
at the 2- positions. By condensation with other aldehydes, several new
viologens were made.
In addition, new compounds were made from diamines in which the
delocalized system of the viologen was extended over up to six aromatic
rings, from the nitrogen atoms.
Model experiments were often performed using pyridinium salts rather
than bipyridinium salts, and, because of the chemical differences
between the two systems, interesting compounds were made with the
former but not with the latter. Amongst these was the novel Wittig
reaction of a 1-pyridinium ylid with aromatic aldehydes to give
exclusively the unexpected Z-(cis)-olefin products, which are new
compounds.
The feasibility of synthesis of the various envisaged polymer types is
discussed in general terms.

Item Type:	Thesis (PhD)
Subjects:	Q Science > QD Chemistry
Library of Congress Subject Headings (LCSH):	Bipyridinium compounds -- Synthesis
Official Date:	August 1987
Dates:	Date Event August 1987 Submitted
Institution:	University of Warwick
Theses Department:	Department of Chemistry
Thesis Type:	PhD
Publication Status:	Unpublished
Supervisor(s)/Advisor:	Crout, D. H. G.
Sponsors:	Science and Engineering Research Council (Great Britain) (SERC)
Extent:	[12], 178 leaves
Language:	eng

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