Alkyl Substituent Effects on Reductive Elimination Reactions in Zirconocene Alkyl Hydride Complexes. Manipulation of the Alkyl Steric Environment Allows the Synthesis of a Zirconocene Dinitrogen Complex

2003 ◽  
Vol 22 (13) ◽  
pp. 2797-2805 ◽  
Author(s):  
Jaime A. Pool ◽  
Emil Lobkovsky ◽  
Paul J. Chirik
Keyword(s):  
Substituent Effects ◽  
Alkyl Substituent ◽  
Reductive Elimination ◽  
Hydride Complexes ◽  
Elimination Reactions ◽  
Dinitrogen Complex ◽  
Alkyl Hydride

Substituent Effects on Reductive Elimination from Disubstituted Aryl Hydride Complexes: Mechanistic and Thermodynamic Considerations

1995 ◽  
Vol 14 (12) ◽  
pp. 5677-5685 ◽  
Author(s):  
Anthony D. Selmeczy ◽  
William D. Jones ◽  
Robert Osman ◽  
Robin Perutz
Keyword(s):  
Substituent Effects ◽  
Reductive Elimination ◽  
Hydride Complexes

The importance of cyclopentadienyl substituent effects in group 4 metallocene dinitrogen chemistry

2005 ◽  
Vol 83 (4) ◽  
pp. 286-295 ◽  
Author(s):  
Jaime A Pool ◽  
Paul J Chirik
Keyword(s):  
Alkali Metal ◽  
Substituent Effects ◽  
Reductive Elimination ◽  
Sandwich Complex ◽  
Group 4 ◽  
Dinitrogen Complexes ◽  
The Future ◽  
Elimination Reactions

This article highlights some of our recent efforts and presents new data on the importance of cyclopentadienyl substituent effects on group 4 metallocene dinitrogen chemistry. Reactions such as the coordination of N2 to an isolated titanium sandwich complex, alkali-metal reductions of zirconocene dihalide complexes, alkane reductive elimination reactions, and the hydrogenation of zirconium dinitrogen complexes are all extremely sensitive to the groups present on the cyclopentadienyl rings. These results are promising for the future of N2 fixation, as the reactivity of a specific metallocene can be dramatically altered by subtle manipulations in ligand substituents.Key words: cyclopentadienyl, zirconium, dinitrogen, ammonia, sandwich.

Kinetic Study of Hydrolysis of Benzoates. Part XXVI. Variation of the Substituent Effect with Solvent in Alkaline Hydrolysis of Substituted Alkyl Benzoates

2006 ◽  
Vol 71 (11-12) ◽  
pp. 1557-1570 ◽  
Author(s):  
Vilve Nummert ◽  
Mare Piirsalu ◽  
Ilmar A. Koppel
Keyword(s):  
Kinetic Study ◽  
Alkaline Hydrolysis ◽  
Rate Constants ◽  
Substituent Effect ◽  
Substituent Effects ◽  
Alkyl Substituent ◽  
Solvent Parameters ◽  
Substituent Constants ◽  
Hydrolysis Of ◽  
Main Factor

The second-order rate constants k2 (dm3 mol-1 s-1) for the alkaline hydrolysis of substituted alkyl benzoates C6H5CO2R have been measured spectrophotometrically in aqueous 0.5 M Bu4NBr at 50 and 25 °C (R = CH3, CH2Cl, CH2CN, CH2C≡CH, CH2C6H5, CH2CH2Cl, CH2CH2OCH3, CH2CH3) and in aqueous 5.3 M NaClO4 at 25 °C (R = CH3, CH2Cl, CH2CN, CH2C≡CH). The dependence of the alkyl substituent effects on different solvent parameters was studied using the following equations:      ∆ log k = c0 + c1σI + c2EsB + c3∆E + c4∆Y + c5∆P + c6∆EσI + c7∆YσI + c8∆PσI     ∆ log k = c0 + c1σ* + c2EsB + c3∆E + c4∆Y + c5∆P + c6∆Eσ* + c7∆Yσ* + c8∆Pσ* .  ∆ log k = log kR - log kCH3. σI and σ* are the Taft inductive and polar substituent constants. E, Y and P are the solvent electrophilicity, polarity and polarizability parameters, respectively. In the data treatment ∆E = ES - EH2O , ∆Y = YS - YH2O , ∆P = PS - PH2O were used. The solvent electrophilicity, E, was found to be the main factor responsible for changes in alkyl substituent effects with medium. When σI constants were used, variation of the polar term of alkyl substituents with the solvent electrophilicity E was found to be similar to that observed earlier for meta and para substituents, but twice less when σ* constants were used. The steric term for alkyl substituents was approximately independent of the solvent parameters.

scholarly journals Force-modulated reductive elimination from platinum(ii) diaryl complexes

2021 ◽  
Author(s):  
Yichen Yu ◽  
Chenxu Wang ◽  
Liqi Wang ◽  
Cai-Li Sun ◽  
Roman Boulatov ◽  
...  
Keyword(s):  
Transition State ◽  
Reductive Elimination ◽  
Mechanical Force ◽  
Elimination Reactions

The influence of mechanical force on the rates of model reductive elimination reactions depends on the structure of the force-transducing ligand and provides a measure of geometry changes upon reaching the transition state.

Diverse mechanisms of carbon-hydrogen bond formation through binuclear reductive elimination reactions

1982 ◽  
Vol 104 (2) ◽  
pp. 619-621 ◽  
Author(s):  
Mario J. Nappa ◽  
Roberto Santi ◽  
Steven P. Diefenbach ◽  
Jack Halpern
Keyword(s):  
Hydrogen Bond ◽  
Bond Formation ◽  
Reductive Elimination ◽  
Hydrogen Bond Formation ◽  
Elimination Reactions

Studies on molybdenocene derivatives: Reactions of [Cp2Mo(η2-NCMe)] and preparation of alkyl hydride complexes. Crystal structure of [Cp2Mo(PMe3)]

1993 ◽  
Vol 445 (1-2) ◽  
pp. 125-131 ◽  
Author(s):  
Cristina G. de Azevedo ◽  
M.Arménia A.F. de C.T. Carrondo ◽  
Alberto R. Dias ◽  
Ana M. Martins ◽  
M.Fátima M. Piedade ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydride Complexes ◽  
Alkyl Hydride
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