2-Hydroxyazobenzenes to Tailor pH Pulses and Oscillations with Light
作者:Matthieu Emond、Thomas Le Saux、Sylvie Maurin、Jean-Bernard Baudin、Raphael Plasson、Ludovic Jullien
DOI:10.1002/chem.201000541
日期:2010.8.2
evaluates the 2‐hydroxyazobenzene platform for tailoring proton concentration pulses and oscillations with monochromatic light. The easily prepared 2‐hydroxyazobenzenes exhibit large absorptions in the near‐UV range. Photoisomerization was investigated by UV/Vis absorption, 1H NMR spectroscopy, and steady‐state fluorescence emission. In the whole investigated series, the trans stereoisomer of the 2‐hydroxyazobenzene
本文评估了2-羟基偶氮苯平台,该平台用于调整质子浓度脉冲和单色光的振荡。易于制备的2-羟基偶氮苯在近紫外线范围内表现出较大的吸收率。通过UV / Vis吸收,1 H NMR光谱和稳态荧光发射研究了光致异构化。在整个研究的系列中,2-羟基偶氮苯基序的反式立体异构体提供相应的顺式衍生物,其作用截面在10 3 M -1 cm -1范围内。同时,光异构化伴随着显着的p K苯酚基团的下降。根据苯基取代基图案,顺式-到-反式热回异构化可以在10毫秒-100秒范围内调谐。通过适当地调整2-羟基偶氮苯溶液的单波长照射,在10 s的时间尺度上可获得多达2个单位的可逆pH下降或pH振荡。
Substituent effect on the [2?+?3] cycloaddition of (E)-?-Nitrostyrene with (Z)-C,N-Diarylnitrones
作者:Andrzej Baranski
DOI:10.1002/poc.451
日期:2002.2
(ktotal) of the reaction of (E)-β-nitrostyrene (1) with (Z)-C-phenyl-N-arylnitrones (2a–g) was found to increase with increasing Hammett σ-constant, whereas in the case of (Z)-C-aryl-N-phenylnitrones (2g–p) and the same nitrostyrene the rate decreased. The substituent effect in these reactions is inconsistent with FMO treatments of cycloaddition rates. For both reaction series good linear relationships
es with N-substitutedmaleimides. The compounds were screened for their antibacterial activities and most of them exhibited activity against Enterococcus faecalis (ATCC 29212) and Staphylococcus aureus (ATCC 25923). cis-3a and cis-3d were found fairly effective against E. faecalis (ATCC 29212) and S. aureus (ATCC 25923) with MIC values of 25 and 50microg/ml. With the changes of cis isomers of the compounds