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演講者 : 李俊欽 指導老師 : 于淑君 教授

Syntheses, Characterization and Applications of Palladium Catalysts in Homogeneous, Heterogeneous and Hybrid Forms. 演講者 : 李俊欽 指導老師 : 于淑君 教授. Part 1 :. The Catalytic Activities of the Palladium Nanoparticles in o-Xylene and Ionic Liquids. Pd NPs. Heck Reactions.

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演講者 : 李俊欽 指導老師 : 于淑君 教授

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  1. Syntheses, Characterization and Applications of Palladium Catalysts in Homogeneous, Heterogeneous and Hybrid Forms 演講者 : 李俊欽 指導老師 : 于淑君 教授

  2. Part 1 : The Catalytic Activities of the Palladium Nanoparticles in o-Xylene and Ionic Liquids Pd NPs Heck Reactions

  3. Palladium-Catalyzed Reactions

  4. Types of Pd Catalysts Homogeneous Whitcombe N. J., Hii K. K., Gibson S. E. Tetrahedron2001, 57,7449. Pd/SiO2, Pd/C, Pd/Al2O3, Pd/resin, Pd-modified zeolites Hetrogeneous Pd Nanoparticles (Pd NPs)

  5. The Advantage of Nanoscale Catalysts A nanoparticle of 10 nm diameter would have ~ 10% of atoms on the surface, compared to nearly 100% when the diameter is 1 nm. Rao, C. N. R. Chem. Soc. Rev., 2000,29, 27–35

  6. What Are Ionic Liquids? • Ionic liquids are salts liquids that are composed entirely of ions. • Room Temperature Ionic Liquids :melting points ~100 °C, and sometimes as low as -96 °C

  7. Catalysis in Ionic Liquids General Considerations • no vapor pressure • thermal stability • much greater dissolution capability toward most organic, inorganic and organometallic compounds. • high solubility for gaseous molecules • immiscible with some organic solvents, • a “designer solvents”.

  8. Pd NPs in Ionic Liquid Dupont, J. J. Am. Chem. Soc. 2005, 127, 3298-3299.

  9. The Applications of Pd NPs in Ionic Liquid Dupont, J. J. Am. Chem. Soc. 2005, 127, 3298-3299.

  10. Ionic Liquid & Phase Transfer Wei,G. T.J. Am. Chem. Soc. 2004, 126, 5036-5037

  11. Motivation To study Pd NPs as catalysts for Heck reactions in both molecular solvents and room temperature Ionic Liquids.

  12. Experimental

  13. Syntheses of Pd NPs Pd(hfac)2 : Dihexafluoroacetylacetae Palladium(II)

  14. The TEM Image of Pd NPs Particle size distribution = 16.8 ± 1.4 nm

  15. Preparation of bmimPF6 Ionic Liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim] +PF6-) McEwen, A. B. Thermochim. Acta 2000, 357, 97-102.

  16. General Catalyses of Heck Reaction

  17. Results & Discussions

  18. Yield vs. Reaction Time

  19. TOF vs. Reaction Time 19

  20. Yield vs. Reaction Time 23

  21. TOF vs. Reaction Time 24

  22. Causes of the Low Activity for IL System • Decomposition of IL • Viscosity of IL • Dispersion of Pd NPs in IL

  23. Effects of Base

  24. Conclusion • The catalytic reactivity in term of TOF could be increased by reducing the Pd-to-substrate mole ratio and also by extending the reaction time. • The catalytic activity of Pd NPs in bmimPF6 ionic liquid is restrained due to poor particle dispersion in ionic liquid. • The catalytic activity of Pd NPs in ionic liquid can be enhanced by adding more base to the system.

  25. Part 2 : The Syntheses and Applications of the Palladium(II) Catalyst Supported on Palladium Nanoparticles # * Pd(0)-Ligand-Pd(II)Cl2 py -HNCH2- -CH3 NH

  26. Types of Catalysts

  27. The Componemts of Hybrid Catalyst

  28. Polystyrene-Based Supports : Jang, S. Tetrahedron Lett. 1997, 38, 1793.

  29. Silica-Supported Catalysts : Kinzel, E. J. Chem. Soc. Chem. Commun.1986 1098

  30. Nanosurface : Pfaltz, A. J. Am. Chem. Soc. 2005, 127, 8720-8731.

  31. The Limitation of Phosphine Ligand a. Oxidation b. Metal Leaching Kinzel, E. J. Chem. Soc. Chem. Commun.1986 1098

  32. Bipyridine Ligand Poly(N,N-bipyridyl-endo-norborn-2-ene-5-carbamide)10 Buchmeiser, F. M. R. J. Am. Chem. Soc.1998, 120, 2790.

  33. Motivation • To study the immobilization of molecular Pd(II) complexes on the surfaces of Pd NPs by using the covalent techniques via a specially designed bipyridylphosphinicamidol thiol as spacer ligands. • To investigate the reactivity of hybrid catalyst of this type on a series of heck reaction and look into any possibility of reactivity changes due to the process of immobilization.

  34. Results & Discussions

  35. Synthesis of Spacer-Linker

  36. Synthesis of Molecule Catalyst

  37. Synthesis of Octanethiol Protected Pd NPs 8

  38. Synthesis of Pd(II)-Immobilized Pd NPs 10

  39. TEM Images of TOAB Protected Pd NPs (7) Particle size distribution = 4.1 ± 1.12 nm

  40. TEM Images of Octanethiol Protected Pd NPs (8) Particle size distribution = 4.52± 1.32 nm

  41. TEM Images of Pd(0) –Ligand (9) Particle size distribution = 4.43 ± 1.09 nm

  42. TEM Images of Pd(0) –Ligand-Pd(II)Cl2 (10) Particle size distribution = 4.60 ± 1.26 nm

  43. NMR Spectra of Pd NPs 8 & 9 • HS(CH2)(CH2)(CH2)6CH3 (n-octanethiol, HSR) -CH3 α β α H β H (b) Pd-S(CH2)7CH3 (Pd-SR)(8) -CH3 CDCl3 * β H (c) HS(CH2)11N(H)(O)P(2-py)2 (Ligand(4)) -HNCH2- py α H * β H (d) RS-Pd-S(CH2)11N(H)(O)P(2-py)2 (Pd-Ligand)(9) * -HNCH2- py β H # -CH3 45

  44. NMR Spectra of Pd NPs 9 & 10 (a) HS(CH2)11N(H)(O)P(2-py)2 (Ligand(4)) d6-DMSO # * py -HNCH2- NH (b) HO(CH2)11N(H)(O)P(2-py)2PdCl2 (6) # -CH2OH py - HNCH2- NH * (c) RS-Pd-S(CH2)11N(H)(O)P(2-py)2 (Pd-Ligand)(9) # * py -HNCH2- -CH3 NH (d) RS-Pd-S(CH2)11N(H)(O)P(2-py)2PdCl2 (Pd(0)-Ligand-Pd(II)Cl2)(10) * # -CH3 -HNCH2- py NH 46

  45. IR Spectra of n-Octanethiol & Pd NPs 8 47

  46. IR Spectra of Ligand 4, Pd Nanoparticles 9 & 10 1575(py) 1585 (py) 48

  47. IR Spectra of Ligand 4, Pd Nanoparticles 9 & 10

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