substituent effects
Substituent Effects on Spin Density Distribution and Exchange Coupling in Semiquinone Complexes
... of substituent effects in the fashion conducted in Chapter 4 would be ...rigidity, substituent effects, and physical properties such as semiquinone a H values, quinone reduction potentials, ...
186
Substituent effects on Ni 61 NMR chemical shifts
... Typical effects for protons located in the shielding cones of aromatic compounds amount to but a few ppm, 7b and the largest upfield shift due to ring currents, δ( 3 He) of endohedral He complexes of ...
22
Synthesis, assessment of substituent effects from UV, IR, NMR spectra and antimicrobial activities of 2,4-dichloro-5-fluorophenyl chalcones
... In the present investigation the Hammett spectral linearity of the synthesized chalcones has been studied by evaluating the substituent effects on the group frequencies. The assigned spectroscopic data of ...
11
Proton transfer reactions of N aryl triazolium salts : unusual ortho substituent effects
... ortho-substituent effects, we have studied the deuterium exchange reactions of a number of additional triazolium salts 11-14 with heteroatoms or heteroatom substituents in the 2- and/or 6-positions of the ...
20
Substituent Effects on Exchange Coupling: Controlling the Interactions between Unpaired Electrons
... a substituent ortho to both spin-containing groups, and Case II has two substituents ortho/para to both spin-containing ...significant substituent effects, their mesomeric positioning and close ...
154
Substituent effects of the stability of metal chelates
... The stability constants of the chelate compounds of a series of substituted diaroylmethanes with several divalent metals in 75 per cent by volume dioxan-water were measured.. The data we[r] ...
34
Substituent effects of 3,5-disubstituted p-coumaryl alcohols on their oxidation using horseradish peroxidase–H2O2 as the oxidant
... bulky substituent, caused an extreme reduction in the reaction rate, even though its electron-donating effect was almost the same as that of other alkoxyl ...
8
Substituent effects in the mass spectra of substituted benzils
... curves for each ion integrated over the excess energy transfer function, any substituent effect which alters the relationship between PE,V and the breakdown curves will modify the corres[r] ...
287
DFT study and NBO analysis of solvation/substituent effects of 3-phenylbenzo[d]thiazole-2(3H)-imine derivatives
... solvent effects, the mechanistic elucidation of these effects, and careful consideration of the challenges related to the solvent use may assist researchers in the selection and design improved solvent ...
29
Theoretical study of substituent effects on electronic and structural properties and IRspectrum of 1,3,6,8-tetrahalogens pyrene compounds via density functional theory.
... It is clear that from table 2, the total energy for all tetrahalogens pyrene molecules is increase and depending on the atomic number of halogens atoms, and it is observed that substitution of tetrahalogens groups ...
8
Impact of substituent effects on the Raman spectra of structurally related N-substituted diketopyrrolopyrroles
... 4 optimised geometries of N-BOC and N-benzyl systems respectively. An in-depth analysis of these structural analogues and associated differences on progression from non-substituted DPP to phenyl and N-substituted systems ...
19
Axially chiral enamides : rotation barriers, substituent effects, and cyclisation reactions
... 13 to envisage atropisomeric possibilities. However, if both ortho-substituents were replaced with medium-sized alkyl or heteroatom groups, the N-Ar torsion angle and the barrier to rotation around the N-Ar bond were ...
215
Substituent effects in the radical reactions of amino acid derivatives and their analogues
... By examining the RSEs of the A-protected aminomethyl radicals 63 and 141-145, it can be seen that these generally follow a similar pattern of stabilities to those of the corresponding glycyl radicals 73 and 135-139, ...
299
Axially chiral enamides : substituent effects, rotation barriers, and implications for their cyclization reactions
... ABSTRACT: The barrier to rotation around the N-alkenyl bond of 38 N-alkenyl-N-alkylacetamide derivatives was measured ( Δ G ⧧ rotation varied between <8.0 and 31.0 kcal mol −1 ). The most important factor in ...
20
I Electrophilic substitution reactions of some substituted ferrocenes II The effects of heteroannular substituents on the rates of solvolyses of methylferrocenylcarbinly acetates; a comparison with substituent effects in other reactions of ferrocene
... Acetylation of mono- and di substitut ed ferrocenes Competitive acetylation of ferrocene and acetamidoferrocene Ide ntification of isomers D iscussion Molecular orbital calculations Subs[r] ...
193
Structure and reactivity relationships in organic molecules
... substituent effects are essentially inductive, as for all substituents, sigma values seem to be true constants leading to good linear correlations :for many different reaction series and[r] ...
184
4,6 Dichloro 2 methylthio 5 phenylpyrimidine
... of substituent effects, the presence of the phenyl ring in (I) should increase the activity of the Cl atoms, but as found for 4,6-dichloro-2-amino- 5-phenylpyrimidine, nucleophilic displacement of the ®rst ...
9
Substituent, Temperature and Solvent Effects on the Keto Enol EQUILIBRIUM in β Ketoamides: A Nuclear Magnetic Resonance Study
... Substituent effects: The substituents may push or pull electrons inductively or by ...The effects of an electron releasing methoxy group and an electron with- drawing chlorine atom attached at the ...
12
Porphyrin substituent regiochemistry, conformation and packing The case of 5,10 diphenylporphyrin
... Porphyrins are conformationally flexible and their macrocycle conformation can be modulated significantly via metal and substituent effects [1, 2]. At the same time, core and peripheral substituents ...
16
N (2 Chloro 4 nitrophenyl)maleamic acid monohydrate
... The amide moiety is a constituent of many biologically significant compounds. As part of our studies on the substituent effects on the structures and other aspects of N-(aryl)-amides (Gowda et al., 2000; ...
8