Transfer of inductive effect in thiophene series

1976 ◽  
Vol 41 (5) ◽  
pp. 1541-1550 ◽  
Author(s):  
M. Janda ◽  
J. Šrogl ◽  
M. Němec ◽  
K. Kalfus
Keyword(s):  
Inductive Effect ◽  
Thiophene Series

Studies in the thiophene series. III. Anodic oxidation of 2-thenyl alcohol

1972 ◽  
Vol 37 (8) ◽  
pp. 2584-2588 ◽  
Author(s):  
M. Janda ◽  
J. Šrogl ◽  
M. Synáčková
Keyword(s):  
Anodic Oxidation ◽  
Thiophene Series

Inductive effect in EI-mass spectra of some 5,6-dihalogenides and 5,6-halohydrins of 5α-cholestan-3β-ol and 3β-acetoxy-5α-cholestane

1982 ◽  
Vol 47 (11) ◽  
pp. 2946-2960 ◽  
Author(s):  
Antonín Trka ◽  
Alexander Kasal
Keyword(s):  
Mass Spectra ◽  
Inductive Effect ◽  
Molecular Ions ◽  
Hydroxyl Group ◽  
Halogen Atoms ◽  
Derivatives Of

Partial EI-mass spectra of 3β-hydroxy- and 3β-acetoxy-5α-cholestanes substituted in positions 5α-, 6β- or 5α,6β- with a hydroxyl group or halogen atoms (fluorine, chlorine, bromine) are presented. The molecular ions of 5α,6β-disubstituted derivatives of 3β-hydroxy-5α-cholestane (or of its 3-acetate) are considerably more stable than the corresponding monosubstituted derivatives if at least one of the pair of the vicinal substituents is chlorine or fluorine. This increase in stability, most striking in 5α- and 6β-fluoro compounds, is explained by the inductive effect.

Principal component analysis of substituent constants

1990 ◽  
Vol 55 (1) ◽  
pp. 55-62 ◽  
Author(s):  
Drahomír Hnyk
Keyword(s):  
Principal Component Analysis ◽  
Inductive Effect ◽  
Resonance Effect ◽  
Principal Component ◽  
Component Analysis ◽  
Total Variance ◽  
Data Matrix ◽  
Cumulative Proportion ◽  
Two Factors ◽  
Substituent Constants

The principal component analysis has been applied to a data matrix formed by 7 usual substituent constants for 38 substituents. Three factors are able to explain 99.4% cumulative proportion of total variance. Several rotations have been carried out for the first two factors in order to obtain their physical meaning. The first factor is related to the resonance effect, whereas the second one expresses the inductive effect, and both together describe 97.5% cumulative proportion of total variance. Their mutual orthogonality does not directly follow from the rotations carried out. With the help of these factors the substituents are divided into four main classes, and some of them assume a special position.

Chemometric Analysis of Substituent Effects. VII. Inductive Effect as a Basic Substituent Effect. Isoeffect Substituent Constant

1995 ◽  
Vol 60 (8) ◽  
pp. 1316-1332 ◽  
Author(s):  
Oldřich Pytela ◽  
Aleš Halama
Keyword(s):  
Inductive Effect ◽  
Chemical Shifts ◽  
Quantitative Description ◽  
Substituent Effects ◽  
Intersection Point ◽  
Chemometric Analysis ◽  
Reaction Centre ◽  
Substituent Constant ◽  
Modified Method ◽  
Substituted Benzoic Acids

The paper deals with chemometric analysis of the inductive effect. The notion of inductive effect is discussed, and unambiguous definitions are given for the notions of triad: reaction centre-basic skeleton-substituent, and the therewith connected definitions of inductive effect. For a quantitative description of inductive effect 7 types of chemical models were selected including noncyclic compounds, cyclic, and bicyclic compounds, derivatives of quinuclidine, 3-substituted benzoic acids, sulfonamides and pyridines. Altogether 139 sets of experimental data from literature have been used including altogether 1 294 points (9.3 points per set, 5 points at least) reflecting substituent effects of 34 substituents. It has been found that for a standard model the dissociation of substituted bicycloalkanecarboxylic acids only is satisfactory, all the other models reflecting also the mesomeric effects to variable extent (up to 10%). A distinctly different substitution behaviour was observed with 19F and 13C NMR chemical shifts of 4-substituted 1-fluoro- or 1-methylbicyclo[2.2.2]octanes. The earlier suggested model of substituent effects based on different way of transmission of substituent effects (3 classes) has been used for separating the inductive and mesomeric effects: it is mathematically presented as a set of straight lines with the intersection point at the so-called isoeffect substituent constant. Using the modified method of conjugated deviations a chemometric scale has been created for the inductive effect which agrees very well with the conventional scales given in literature; the only differences were observed for F and CH=O substituents (which are overestimated and underestimated, respectively, in literature). In the context given the inductive effect appears as a fundamental quantity forming a basis for quantitative description of other effects transferred by electrons.

Inductive Effect as a Universal Concept to Design Efficient Catalysts for CO2 Electrochemical Reduction: Electronegativity Difference Makes Difference

2021 ◽  
Author(s):  
Huihuang Chen ◽  
Weng Fu ◽  
Zhigang Geng ◽  
Jie Zeng ◽  
Bo Yang
Keyword(s):  
Electrochemical Reduction ◽  
Energy Supply ◽  
Environmental Remediation ◽  
High Performance ◽  
Inductive Effect ◽  
Great Promise ◽  
Electronegativity Difference

CO2 electrochemical reduction (CO2ER) into valuable chemical feedstocks holds great promise for energy supply and environmental remediation but remains a challenge due to the lack of high-performance electrocatalysts. Inductive effect,...

The Bond N -Cl. A Spectroscopic (35Cl-NQR, IR) Investigation

1994 ◽  
Vol 49 (6) ◽  
pp. 695-702 ◽  
Author(s):  
B. Thimme Gowda ◽  
Alarich Weiss
Keyword(s):  
Phenyl Ring ◽  
Electron Distribution ◽  
Inductive Effect ◽  
Aqueous Media ◽  
Phenyl Group ◽  
Vibration Frequencies ◽  
Resonance Frequencies ◽  
35Cl Nqr ◽  
Cl Atoms ◽  
Cl Atom

Abstract Chlorine bound to nitrogen is an interesting oxidizing agent in aqueous, partial aqueous and non-aqueous media. One can assume that the oxidizing action of the chlorine depends on the polarization of the Cl atom in the bond N -Cl which will depend on the electron distribution in the ligands R and R″ of the configuration R -NCl -CO -R″. 17 compounds were synthesized with R = substituted phenyl radical C6H5-y Xy, X = Cl, NO2, R″ = CH2Cl. The 35Cl NQR frequencies are observed in the range 52 to 54 MHz (T = 77 K) for the Cl(N) 34 to 37 MHz for the phenyl chlorines and the CH2Cl group. Their temperature dependence was followed up to 300 K. Therefrom the assignment of the resonance to certain Cl-atoms in the molecules is possible. Generally, the substitution of a negative substituent X (Cl, NO2) in the phenyl ring raises the resonance frequencies; the influence of the CH2Cl group on the N -Cl bond is weak. Strong is the influence of the carbonyl group on the N -C l bond. The IR group frequencies ν(C = O) are found in the range 1680 ≤ ν (C = O)/ cm−1≤ 1717, shifted up by ≤ 20 cm−1 compared to the corresponding acetamide R ⎯ NH ⎯CO ⎯ R″. Influence of the phenyl ring substitution on ν (C = O) does not follow a simple law of inductive effect. Also a correlation between the vibration frequencies of the N ⎯ Cl group and the phenyl group substitution is not found.

Solubilities of the silver halides in propylene carbonate mixtures with bis(trifluoroethyl)sulfite

1977 ◽  
Vol 55 (13) ◽  
pp. 2499-2503 ◽  
Author(s):  
Mark Salomon
Keyword(s):  
Propylene Carbonate ◽  
Inductive Effect ◽  
Mixed Solvents ◽  
Chemical Properties ◽  
Silver Ions ◽  
Halide Ions ◽  
Silver Halides

The complex solubilities of AgCl, AgBr, and AgI have been measured in several mixed solvents containing propylene carbonate and bis(trifluoroethyl)sulfite. The results indicate that a large inductive effect destabilizes the solvation of silver ions whereas the halide ions appear to be stabilized by coordination with the sulfinyl sulfur. Several physio-chemical properties of pure bis(trifluoroethyl)sulfite are reported.

Sign in / Sign up

Export Citation Format

Share Document