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'Inductive effect' in keywords
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1996 (1)
1978 (2)
1Author    Milan StrašákRequires cookie*
 Title    Substituent Effects in the Oxythallation of Alkenes  
 Abstract    The rate constants for oxythallation of alkenes have been correlated with their experi-mental and calculated ionization potentials respectively. A good correlation between the rate constants and the ionization potentials of alkenes was found. It was found that inductive effects were the most important in the oxythallation of RCH —CH2 and RiR2C = CH2 alkenes. From earlier studies [1, 2] it is obvious that the rate determining step of the oxidation of alkenes by thallic salts is the formation of the intermediate oxythallation adduct according to Eq (1): R2C=CR2 + T13+ + H20 -> [CR2(0H)CR2T1]2+ + H+ (1) 
  Reference    Z. Naturforsch. 33b, 224—227 (1978); received October 20 1977 
  Published    1978 
  Keywords    Alkenes, Oxythallation, Kinetics, Inductive Effect, Ionization Potentials 
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 TEI-XML for    default:Reihe_B/33/ZNB-1978-33b-0224.pdf 
 Identifier    ZNB-1978-33b-0224 
 Volume    33 
2Author    George Sosnovsky, Maria KoniecznyRequires cookie*
 Title    Investigation of Inductive Effects on the Transphosphorylation Reaction of Spin-Labeled Phosphoryl Imidazolides, Part II  
 Abstract    The effect of electron-releasing and electron-withdrawing groups in the benzene ring of imidazolide 4 (R 1 = CH3, Cl, NO2) was studied. The 
  Reference    Z. Naturforsch. 33b, 797—804 (1978); received March 17 1978 
  Published    1978 
  Keywords    Spin-labeled Phosphates, Spin-labeled Phosphoroamidates, Nitroxyl Radical, Imidazole, Inductive Effects 
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 TEI-XML for    default:Reihe_B/33/ZNB-1978-33b-0797.pdf 
 Identifier    ZNB-1978-33b-0797 
 Volume    33 
3Author    Serge David, Michel Gourdji, Lucien Guibé, Alain PéneauRequires cookie*
 Title    Chlorine Substituted Acetic Acids and Salts. Effect of Salification on Chlorine-35 NQR  
 Abstract    The NQR of a quadrupolar probe nucleus is often used to investigate the effect of substituent in molecules. The inductive effect, based on a partial charge migration along the molecular skeleton is the only one present in saturated aliphatics, the conjugative effect appearing in conjugated molecules, especially aromatics. As the stepwise charge migration mechanism, formerly used to explain the inductive effect, is now believed obsolete, we have wanted to reexamined the case of chlorine substituted acetic acids and salts. The data in literature was extended by observing reso-nances and determining NQR frequencies in several acids and salts. The present analysis of the salification of mono-, di-and tri-chloroacetic acids, which is equivalent to a deprotonation or the substitution of the acid hydrogen by a negative unit charge, shows that a model based on the polarization of the chlorine atom(s) by the carboxyle group is consistent with experimental results: the polarization energy appears to be proportional to the NQR frequency shifts; experimental data show a correlation between the NQR frequency shifts accompanying salification and the variations of the intrinsic acidity measured in the gas phase; this, in turn shows that there is a proportionality between the polarization energy and the variations in the acid free enthalpy of dissociation. From the comparison between fluorine, chlorine, bromine and iodine, it also appears that an alternative mechanism, the polarization of the carboxyl group by the halogen, would be important only in the case of the fluoroacetic acid. 
  Reference    Z. Naturforsch. 51a, 611—619 (1996); received October 10 1995 
  Published    1996 
  Keywords    35 C1 NQR, Chloroacetic acids, Substituent effect, Inductive effect, Polarization, Intrin-sic acidity 
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 TEI-XML for    default:Reihe_A/51/ZNA-1996-51a-0611.pdf 
 Identifier    ZNA-1996-51a-0611 
 Volume    51