Solvatochromic probes ring-substituted

Under this heading are collected solvatochromic probes which have an amino group attached to a phenyl ring that in turn is bonded by more than one bond to other moieties (Schemes 2 and 3). All these groups are generally further substituted in order to produce chromophores that have a wide solvatochromic amplitude. 

Circular dichroism (CD) is a very sensitive spectroscopic tool for probing chain conformations in optically active polymers. For example, with peptides, CD spectroscopy has been widely employed to estimate the proportion of the chain present as the alternative a-helix, P-sheet and random coil conformations. Following our recent discovery of both electrochemical - and chemicaP i routes to chiral PAn.HCSA and related ring-substituted emeraldine salts, we have employed CD spectroscopy extensively to (a) distinguish between "extended coil" and "compact coil" PAn conformations, (b) probe redox and pH switching in PAn, (c) characterize conformational changes in solvatochromism and thermochromism for PAn, and (d) distinguish unequivocally between the conformations/structures of electrochemically and chemically prepared PAn. Similar valuable information on poly-... 

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