Aromatic Hydrogens and Electron Withdrawing Groups是NMR系列8:Nuclear Magnetic Resonance 12节课的第3集视频,该合集共计12集,视频收藏或关注UP主,及时了解更多相关视频内容。
Perylene dicarboximide dimer with electron withdrawing groups were synthesized and fully characterized by ~1H-NMR and ~(13)C-NMR spectra. The effects of the substituted groups on the optical and electrochemical properties of the two compounds were investigated. The π–π~* absorption peak of the...
ChemInform Abstract: The Effect of Electron-Donating and Electron-Withdrawing Substituents on 1H and 13C NMR Chemical Shifts of Novel 7′-Aryl-Substituted ... ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. ...
Congested Ferrocenyl Polyphosphanes Bearing Electron-Donating or Electron-Withdrawing Phosphanyl Groups: Assessment of Metallocene Conformation from NMR Sp... The synthesis of novel substituted cyclopentadienyl salts that incorporate both a congested branched alkyl group (tert-butyl, (triphenyl)methyl, or ...
Indoles having substituents at both the 2- and 3-positions may yield products derived from the initial formation of 2,3,3-trisubstituted 3H-indoles, but when the system is substituted at the 1-, 2- or 3-position by electron-withdrawing groups, thereby rendering the five-membered ring less ...
Correlations between carbon-13 nuclear magnetic resonance and X-ray crystallography for pyrroles containing electron-withdrawing groupsThe C NMR chemical shifts of benzyl 4-ethyl-3,5-dimethylpyrrole-2-carboxylate (I), Me E-3-(3-ethyl-4,5-dimethylpyrrol-2-yl)-2-cyanopropenoate (II), and Me...
We therefore decided to prepare more reactive versions of the reagents 1 by the attachment of an electron-withdrawing group such as a trifluoromethyl substituent (R = CF3) in the para-position to the iodine (Figure 1). This should enhance the electrophilicity of the hypervalent iodine reagents ...
NMR spectra were recorded on a Bruker AVANCE 500 MHz spectrometer. J-V characteristics were measured using a Keithley source/meter under AM 1.5 G simulated sunlight of 100 mW?cm22 light intensity from a Newport 300 W solar simulator. Incident photon-to-current conversion efficiencies (IPCE) ...
This confirms the experimental observation that negative charges are mainly localized on the coordinated phenyl ring, while the uncoordinated phenyl ring acts only as an electron withdrawing group. Impor- tantly, the putative complex 5-Y2 À , in which each yttrium ion is coordinated to a ...
The results indicate that the inductive effects of electron-withdrawing functionality diminish transfection activity in modest (2–4-fold) increments. The present study suggests that the mechanism whereby poly(alcohol)- or poly(ether)-substituted headgroups improve DNA transfection is not based on ...