Unprecedented four-way-output molecular response system based on biphenyl-2,2′-diyldiacridiniums: induction of axial chirality through intramolecular hydrogen bonds between chiral amide groups
Upon the attachment of N-(R)-2-phenylethylamide moieties to the acridinium units of the title dication, intramolecular hydrogen bonds induce a diastereomeric preference in terms of axial chirality (70% de at -40 degrees C in CH2Cl2). Thus, external stimuli induce not only UV-vis and fluorescence spectra changes but also changes in the CD and fluorescence-detected CD (FDCD) spectra, realizing unprecedented four-way-output molecular response systems. (C) 2007 Elsevier Ltd. All rights reserved.
A novel redox switch for fluorescence: drastic UV–vis and fluorescence spectral changes upon electrolysis of a hexaphenylethane derivative of 10,10′-dimethylbiacridan
The newly prepared title donor 1 has a very long CC bond [1.635(2) Å], which was readily cleaved upon oxidation to give dication 22+ containing two 10-methylacridinium chromophores. Colorless donor 1 (Eox +0.18 V) is non-fluorescent whereas orange dication 22+ (Ered −0.27 V) emits strong green fluorescence, so that, this pair can be considered as a novel redox switch for fluorescence with high electrochemical
新制备的标题供体1具有非常长的CC键[1.635(2)Å],该键很容易在氧化时裂解,得到含有2个10-甲基rid基发色团的金属2 2+。无色供体1(E ox +0.18 V)不发荧光,而橙色指示剂2 2+(E red -0.27 V)发出强绿色荧光,因此,该对可被视为具有高电化学性能的新型荧光氧化还原开关双稳性。