Heavy‐Atom and Substituent Effects on S—T Transitions of Halogenated Carbonyl Compounds

1967 ◽  
Vol 46 (6) ◽  
pp. 2333-2341 ◽  
Author(s):  
Raymond F. Borkman ◽  
David R. Kearns
Keyword(s):  
Carbonyl Compounds ◽  
Heavy Atom ◽  
Substituent Effects

Spectral signs of the internal heavy-atom effect in aliphatic carbonyl compounds

1974 ◽  
Vol 17 (9) ◽  
pp. 1266-1268
Author(s):  
L. V. Orlovskaya ◽  
I. V. Sokolova
Keyword(s):  
Carbonyl Compounds ◽  
Heavy Atom ◽  
Heavy Atom Effect ◽  
Atom Effect

scholarly journals Carbonyl Addition Reactions: Factors Affecting the Hydrate–Hemiacetal and Hemiacetal–Acetal Equilibrium Constants

1975 ◽  
Vol 53 (6) ◽  
pp. 898-906 ◽  
Author(s):  
J. Peter Guthrie
Keyword(s):  
Aqueous Solution ◽  
Carbonyl Compounds ◽  
Equilibrium Constants ◽  
Substituent Effects ◽  
Steric Effects ◽  
Addition Reactions ◽  
Free Energies ◽  
Electronic Effects ◽  
Factors Affecting ◽  
Analogous Formula

Equilibrium constants for hydrate–hemiacetal interconversion in aqueous solution at 25° have been measured for four fluorinated carbonyl compounds: compound, alcohol, K4 (M−1): CF3CHO, C2H5OH, 2.3; CF3COCH3, CH3OH, 1.0; CF3COPh, CH3OH, 3.5; CF3COCF3, CH3OH, 0.14. These values, combined with values from the literature, permit an examination of substituent effects upon the equilibrium constant for[Formula: see text]The free energy change for this process, corrected for symmetry and steric effects, follows the equation[Formula: see text]Thus electronic effects upon this equilibrium are generally small and in fact are often smaller than steric effects.This analysis permits and justifies the calculation of free energies of formation of [Formula: see text] compounds from the (more generally measurable) free energies of formation of the analogous [Formula: see text] compounds.

Isotope effects in nucleophilic substitution reactions. III. The effect of changing the leaving group on transition state structure in SN2 reactions

1979 ◽  
Vol 57 (11) ◽  
pp. 1354-1367 ◽  
Author(s):  
Kenneth Charles Westaway ◽  
Syed Fasahat Ali
Keyword(s):  
Transition State ◽  
Nucleophilic Substitution ◽  
Isotope Effects ◽  
Heavy Atom ◽  
Substituent Effects ◽  
Kinetic Isotope Effects ◽  
Substitution Reactions ◽  
Nucleophilic Substitution Reactions ◽  
Kinetic Isotope ◽  
Leaving Group

The nucleophilic substitution reactions of a series of 4-substituted phenylbenzyldimethyl-ammonium ions with thiophenoxide ions at 0 °C in N,N-dimethylformamide have been used to demonstrate how a change in the leaving group alters the structure of the SN2 transition state. Heavy atom (nitrogen) kinetic isotope effects, secondary α-deuterium kinetic isotope effects and Hammett ρ values provide qualitative descriptions of both the nucleophile–α-carbon and α-carbon–leaving group bonds in the transition states of these reactions. The results indicate that changing to a better leaving group causes the bond between the α-carbon and the nucleophile to be much more fully formed while the bond to the leaving group is essentially unchanged. The results are discussed in the light of current theories of substituent effects on SN2 reactions and a possible explanation for the surprising results (i) that the greatest effect is in the bond more remote from the point of structural change and (ii) that more nucleophilic assistance is required to displace a better leaving group is given.

Gas phase basicities of fluorocarbonyl compounds. An ion cyclotron resonance investigation of the effects of fluorine and trifluoromethyl substituents on hydroxy carbonium ion stabilities

1981 ◽  
Vol 59 (18) ◽  
pp. 2689-2694 ◽  
Author(s):  
C. E. Doiron ◽  
T. B. McMahon
Keyword(s):  
Gas Phase ◽  
Carbonyl Compounds ◽  
Cyclotron Resonance ◽  
Substituent Effects ◽  
Ion Cyclotron Resonance ◽  
Proton Affinities ◽  
Resonance Investigation ◽  
Carbonium Ion ◽  
Hydrogen Bonding Interactions ◽  
Gas Phase Basicities

Gas phase proton affinities for a number of fluoro- and trifluoromethyl-substituted carbonyl compounds have been obtained using a combination of proton transfer equilibria and bracketing experiments. Absolute and relative substituent effects for F and CF3 on carbonyl basicities are determined and discussed in terms of inductive, resonance, polarization, and hydrogen bonding interactions. The data are used to interpolate basicities for HCOF and CF3CHO and are compared to theoretical ab initio calculations.

scholarly journals Synthesis, characterization and biological evaluation of new manganese metal carbonyl compounds that contain sulfur and selenium ligands as a promising new class of CORMs

2019 ◽  
Vol 48 (17) ◽  
pp. 5574-5584 ◽  
Author(s):  
André L. Amorim ◽  
Marcos M. Peterle ◽  
Ana Guerreiro ◽  
Daniel F. Coimbra ◽  
Renata S. Heying ◽  
...  
Keyword(s):  
Carbonyl Compounds ◽  
Heavy Atom ◽  
Metal Carbonyl ◽  
Biological Evaluation ◽  
New Class ◽  
Manganese Carbonyl ◽  
Potential Use

Three new manganese carbonyl compounds with heavy atom donors were synthesized and their potential use as photoCORMS was evaluated.

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