Rigid rod polymers with stacked electron donor‐acceptor side‐chains

Abstract

Please be advised that this information was generated on 2018-05-10 and may be subject to change. Pays-Bas, 105/9, september 1986 255 ether extracts of the aqueous phase. Most of the diol mixture (1.09 g, 84 %) was found in the precipitate. After drying (M g S 0 4) and removal of solvent, the crude diol mixture (1.22 g, 93%) was obtained. Recueil des Travaux Chimiques des Separation of diolsThis was effected (700 mg product per column) using silica (150 g; Woelm, 100-200, aktiv) in a 42 cm x 39 mm column. A slurry of silica in hexane was poured into the column. Eluents were hexane/EtOAc: 9/1 (200 ml), 4/1 800 ml), 7/3 (3000 ml), 3/7 (1000 ml). More polar eluents cause exothermic reaction with silica, moderated by external cooling to 5 -1 0°C using a wet ice-cold cloth.The order of elution was diol 2 (235 mg, 34%) followed by diol 3 (310 mg, 44%, both after purification). Total yield from the column was 86%; of pure diols 78%. Each diol showed only one TLC spot. Department of Organic Chemistry, University of Utrecht, Padualaan 8, 3584 CH Utrecht, The Netherlands (Received February 10th, 1986) Abstract.The synthesis of polymers of isocyanides having stacks of donor and acceptor functions in their side-chains is described. These side-chains are based on the betaine compounds used by Dimroth et al. for the construction of their ET scale of solvent polarity. The UV-VIS spectra of the polymers together with those of the low-molecular-weight model compounds are discussed. Svn,svn-D'\o\

Synthesis and structures of crystalline solvates formed of pyridinium N-phenoxide (Reichardt's-type) betaine dyes and alcohols

“…The synthesis of the new Reichardt's type betaine dyes 2-5 (Scheme 2) was accomplished following on principle the established procedures for the preparation of para-pyridinium N-phenoxides. 4,28,29 Here, the respective 2,6-diaryl-substituted 4-aminophenols 10a-d, obtained by hydrogenation of the corresponding nitrophenols 9a-d, were condensed with 2,4,6triphenylpyrylium hydrogen sulfate (11) in the presence of sodium acetate to give, on addition of sodium hydroxide, the respective betaines. The nitrophenols 9a-d were obtained by condensation reaction between 2-nitromalonaldehyde-Na (8) and the corresponding 1,3-diaryl-substituted propan-2-ones 7a-d. 30 The ketones 7a-d were synthesized from 6a-d using two alternative literature procedures specified as A 31 and B 32 in Scheme 2.…”

“…29 Synthesis of the betaine dyes 2-5. To the above solutions of the corresponding aminophenol 10a-d (2.5 mmol) in EtOH were added under Ar 2,4,6-triphenylpyrylium hydrogensulfate (11) (1.0 g, 2.5 mmol) and anhydrous sodium acetate (1.0 g, 12 mmol). The mixture was heated to reflux for 3 h. Then, 5% aqueous NaOH solution (7.5 mL) was added to the hot solution.…”

“…3 The standard pyridinium N-phenoxide betaine dye 1 (Scheme 1) exhibiting extraordinarily large negative solvatochromism has been used to set up an empirical scale of solvent polarity [E T (30) values] 4,5 to probe micellar environments 6 and to determine the composition of binary solvent mixtures 7 including the amount of water in organic solvents. 8 Moreover, chemical sensor development 9 and other materials' design 10,11 have taken advantage of the particular behavior of the betaine dyes.…”