Search

Your search keyword '"Feng-Zhao Yang"' showing total 3 results
Start Over Author "Feng-Zhao Yang" Journal inorganic chemistry
3 results on '"Feng-Zhao Yang"'

1. Kinetic and mechanistic studies of geometrical isomerism in neutral square-planar methylpalladium complexes bearing unsymmetrical bidentate ligands of [alpha]-aminoaldimines

Author

Feng-Zhao Yang, Yu-Heng Wang, Mu-Chieh Chang, Kuo-Hsuan Yu, Shou-Ling Huang, Yi-Hung Liu, Yu Wang, Shiuh-Tzung Liu, and Jwu-Ting Chen

Subjects
Isomerism -- Analysis, Methyl groups -- Chemical properties, Methyl groups -- Structure, Nuclear magnetic resonance -- Usage, Palladium catalysts -- Chemical properties, Palladium catalysts -- Structure, Chemistry
Published
2009

2. Kinetic and Mechanistic Studies of Geometrical Isomerism in Neutral Square-Planar Methylpalladium Complexes Bearing Unsymmetrical Bidentate Ligands of α-Aminoaldimines

Author

Yu Wang, Mu-Chieh Chang, Feng-Zhao Yang, Yi-Hung Liu, Shiuh-Tzung Liu, Yu-Heng Wang, Shou-Ling Huang, Jwu-Ting Chen, and Kuo-Hsuan Yu

Subjects
Inorganic Chemistry, Steric effects, Substitution reaction, chemistry.chemical_compound, Denticity, chemistry, Stereochemistry, Ligand, Imine, Physical and Theoretical Chemistry, Isomerization, Cis–trans isomerism, Methyl group
Abstract

A series of hemilabile ligands of alpha-aminoaldimines and their methylpalladium complexes have been prepared and characterized. Neutral square-planar methylpalladium complexes in the form of [R(1)R(2)NCMe(2)CH horizontal lineNR]Pd(Me)Cl (R = Me, R(1) = R(2) = Me (3a); R = Me, R(1) = R(2) = Et (3b); R = Et, R(1) = R(2) = Me (4a); R = (n)Pr, R(1) = R(2) = Me (5a); R = (i)Pr, R(1) = R(2) = Me (6a); R = (i)Pr, R(1) = R(2) = Et (6b); R = (i)Pr, (R(1), R(2)) = c-C(4)H(8) (6c); R = (i)Pr, R(1) = (i)Pr, R(2) = H (6d); R = (i)Pr, R(1) = (t)Bu, R(2) = H (6e); R = (t)Bu, R(1) = R(2) = Me (7a); R = (t)Bu, R(1) = R(2) = Et (7b); R = (t)Bu, (R(1), R(2)) = c-C(4)H(8) (7c); R = (t)Bu, R(1) = (i)Pr, R(2) = H (7d); R = (t)Bu, R(1) = (t)Bu, R(2) = H (7e); R = Ph, R(1) = R(2) = Me (8a); R = Ph, R(1) = R(2) = Et (8b)) show geometrical isomerism. The relative ratios of trans/cis isomers appear to be predominated by the steric hindrance between the Pd-bound methyl group and imino or amino substituents (R and R(1) and R(2)). The NMR studies for the substitution reaction of (COD)Pd(Me)Cl with Et(2)NCMe(2)CH horizontal lineN(i)Pr at -20 degrees C indicate that cis-6b is the major kinetic product, which isomerizes to the thermodynamic product in trans form quantitatively above -5 degrees C. Kinetic results show that the ligand substitution reaction likely undergoes an associative pathway, and the isomerization reaction proceeds via an intramolecular process that comprises imine dissociation and recoordination.

Published
2009

3. Kinetic and Mechanistic Studies of Geometrical Isomerism in Neutral Square-Planar Methypalladium Complexes Bearing Unsymmetrical Bidentate Ligands of α-Aminoaldimines.

Author

Feng-Zhao Yang, Yu-Heng Wang, Mu-Chieh Chang, Kuo-Hsuan Yu, Shou-Ling Huang, Yi-Hung Liu, Yu Wang, Shiuh-Tzung Liu, and Jwu-Ting Chen

Subjects
*ISOMERISM, *PALLADIUM compounds, *LIGANDS (Chemistry), *IMINES, *NUCLEAR magnetic resonance, *SUBSTITUTION reactions
Abstract

A series of hemitabile ligands of α-aminoaldimines and their methypalldium complexes have been prepared and characterized. neutral square-planar methypalladium complexes in the form of [R1R2NCMe2CHNR]Pd(Me)Cl(R=Me, R1=R2=Me(3a); R=Me, R1=R2=Et (3b); R=Et, R1=R2=Me (4a); R=nPr, R1=R2=Me (5a); R=Pr, R1=R2=Me (6a); R=iPr, R1=R2=Et (6b); R=iPr, (R1, R2)=c-C4H8 (6c); R=iPr, R1=iPr, R2=H (6d); R=iPr, R1=tBu, R2=H(6e); R=tBu, R1=R2=Me (7a); R=tBu, R1=R2=Et (7b); R=tBu, (R1, R2)=c-C4H8 (7c); R=tBu, R1=iPr, R2=H (7d); R=tBu, R1=tBu, R2=H (7e); R=Ph, R1=R2=Me (8a); R=Ph, R1=R2=Et (8b)) show geometrical isomerism. the relative ratios of trans/cis isomers appear to be predominated by the steric hindrance between the Pd-bound methyl group and imino or amino substituents (R and R1 and R2). The NMR studies for the substitution reaction of (COD)Pd(Me)Cl with Et2NCMe2CH=NiPr at -20 °C indicate that cis-6b is the major kinetic product, which isomerizes to the thermodynamic product in trans form quantitatively above -5 °C. Kinetic results show that the ligand substitution reaction likely undergoes an associative pathway; and the isomerization reaction proceeds via an intramolecular process that comprises imine dissociation and recoordination. [ABSTRACT FROM AUTHOR]

Published
2009
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results