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Azulene appended cellulose: Synthesis, optical and chiroptical properties, film formation by electrochemical oxidation
Author(s) -
Redl Franz X.,
Köthe Oliver,
Röckl Karl,
Bauer Walter,
Daub Jörg
Publication year - 2000
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/1521-3935(20001001)201:15<2091::aid-macp2091>3.0.co;2-4
Subject(s) - azulene , chemistry , cellulose , stereochemistry , organic chemistry
Regioselective synthesis using protecting‐group strategy yields azulene‐cellulose conjugates 6‐(azulene‐2‐carboxylate)‐2,3‐di‐ O ‐methyl cellulose AzC‐1 , 6‐(4‐azulene‐1‐yl‐benzoate)‐2,3‐di‐ O ‐methyl cellulose AzC‐2 , and 6‐(azulene‐1‐carboxylate)‐2,3‐di‐ O ‐methyl cellulose AzC‐3 . The spectral and electrochemical properties were investigated and compared with the azulene alkylesters 1 b , 2 b , and 3 b . The relative fluorescence quantum yield of methyl 2‐azulenecarboxylate 1b exceeds that of azulene cellulose AzC‐1 by an order of magnitude. Cellulose derivative AzC‐3 exhibits weak dual emission around 400 nm and 520 nm at room temperature. The circular dichroism (CD) of AzC‐1 , AzC‐2 , and AzC‐3 are reported. Intensity and feature of the CD signals depend on the degree of substitution ( DS ) as shown by AzC‐1 . The CD‐split signals at 280 nm (3A 1 transition of azulene) are likely to result from interacting azulene groups. A regular (helical) structure of the cellulose backbone is postulated, leading to the ( M )‐configuration of the spatial azulene units. Unlike esters 2 b and 3 b azulene appended celluloses AzC‐1 and AzC‐2 electropolymerize under potentiodynamic conditions. Chemically modified electrodes are formed. Dotation sates were characterized by UV‐Vis‐NIR‐spectroelectrochemistry. Azulene appended celluloses are suitable for making conducting electrodes with chiral coating materials.