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 Whitcombe N. J., Hii K. K., Gibson S. E. Tetrahedron 2001, 57,7449. Homogeneous Homogeneous Hetrogeneous Hetrogeneous Pd/SiO2, Pd/C, Pd/Al 2 O 3, Pd/resin, Pd-modified zeolites Pd Nanoparticles (Pd NPs) Pd Nanoparticles (Pd NPs)

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

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

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

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

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

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

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

15 Preparation of bmimPF 6 Ionic Liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim] + PF 6 - ) McEwen, A. B. Thermochim. Acta 2000, 357,

16 General Catalyses of Heck Reaction

17 Results & Discussions

18 Yield vs. Reaction Time

19 TOF vs. Reaction Time 19

20 R1R2 Yield （％） TONTOF H CO 2 Et CO 2 -n-Bu CO 2 -t-Bu CO 2 Me Ph OMe CO 2 Et CO 2 -n-Bu CO 2 -t-Bu CO 2 Me Ph

21 R1R2 time （ hr ） yield （％） H CO 2 Et681 CO 2 -n-Bu694 CO 2 -t-Bu1687 CO 2 Me2493 Ph4852 OMe CO 2 Me3698 Ph3641

22 Pd loading (mole %) yield （ % ） TONTOF

23 Yield vs. Reaction Time 23

24 TOF vs. Reaction Time 24

25 Liquids Viscosity (cP) o-Xylene Water1.0 bmimPF Decomposition of ILDecomposition of IL Viscosity of ILViscosity of IL Dispersion of Pd NPs in ILDispersion of Pd NPs in IL Causes of the Low Activity for IL System

26 Entry Eq.of base vs. ionic liquid Pd conc. (mM) Time （ hr ） Yield （ % ） TONTOFcomment Absolute concentrations are diluted Absolute concentrations are the same Effects of Base

27 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 bmimPF 6 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.

28 Pd(0)-Ligand-Pd(II)Cl 2 * # -HNCH 2 - py NHNH -CH 3 The Syntheses and Applications of the Palladium(II) Catalyst Supported on Palladium Nanoparticles Part 2 :

29 Characteristics of catalysts HomogenousHeterogeneousHybrid Cat. structureKnownUnknownKnown Catalyst modificationEasyDifficultEasy ActivityHighLowHigh SelectivityHighLowHigh Poisoning of cat.High riskLow risk Mechanical strengthLowHigh Cat. stabilitiesLowHigh Conditions of catalysisMildHarshMild Separation ＆ recycle of cat. DifficultEasy IndustrializationDifficultAccessible Types of Catalysts

30 The Componemts of Hybrid Catalyst

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

32 Silica-Supported Catalysts : Kinzel, E. J. Chem. Soc. Chem. Commun

33 Nanosurface : Pfaltz, A. J. Am. Chem. Soc. 2005, 127,

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

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

36 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. Motivation

37 Results & Discussions

38 Synthesis of Spacer-Linker

39 Synthesis of Molecule Catalyst

40 Synthesis of Octanethiol Protected Pd NPs 8

41 Synthesis of Pd(II)-Immobilized Pd NPs 10

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

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

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

45 TEM Images of Pd(0) – Ligand-Pd(II)Cl 2 (10) Particle size distribution = 4.60 ± 1.26 nm

46 (a)HS(CH 2 )(CH 2 )(CH 2 ) 6 CH 3 (n-octanethiol, HSR) (b) Pd-S(CH 2 ) 7 CH 3 (Pd-SR)(8) (c) HS(CH 2 ) 11 N(H)(O)P(2-py) 2 (Ligand(4)) (d) RS-Pd-S(CH 2 ) 11 N(H)(O)P(2-py) 2 (Pd-Ligand)(9) α H CDCl 3 * -CH 3 py * -HNCH 2 - # -CH 3 py -HNCH 2 - * β H α H β H -CH 3 NMR Spectra of Pd NPs 8 & 9 αβ 45

47 NMR Spectra of Pd NPs 9 & 10 (b) HO(CH 2 ) 11 N(H)(O)P(2-py) 2 PdCl 2 (6) # -CH 2 OH - HNCH 2 - * NHNH py (c) RS-Pd-S(CH 2 ) 11 N(H)(O)P(2-py) 2 (Pd-Ligand)(9) py NHNH -HNCH 2 - # * d 6 -DMSO * # -HNCH 2 - (d) RS-Pd-S(CH 2 ) 11 N(H)(O)P(2-py) 2 PdCl 2 (Pd(0)-Ligand-Pd(II)Cl 2 )(10) py NHNH -CH 3 (a) HS(CH 2 ) 11 N(H)(O)P(2-py) 2 (Ligand(4)) NHNH -HNCH 2 - # * py 46

48 IR Spectra of n-Octanethiol & Pd NPs 8 47

49 IR Spectra of Ligand 4, Pd Nanoparticles 9 & (py) 1585 (py) 48

50 IR Spectra of Ligand 4, Pd Nanoparticles 9 & 10

51 IR Spectra of Molecules 5 & (py) 1587 (py)

52 UV-vis Spectra of Molecules 4, 5, 6 & Pd Nanoparticles 8, 9, 10

53 NanoparticleSize (nm) Pd(0) total / Pd(0) sur / n-octanethiol / Ligand 4 ( mole ratio ) Pd(0)-SR (8) 4.52 ± / 0.30 / 0.78 / 0 Pd(0)-ligand (9) 4.43 ± / 0.31 / 0.15 / 0.12 Pd(0)-ligand- Pd(II)Cl 2 (10) 4.60 ± / 0.29 / 0.05 / 0.04 Analytical data of Pd Nanoparticles 8, 9 & 10

54 Cat.R Yield （％） TOF a TOF b Pd(0)-ligand-Pd(II)Cl 2 (10) CO 2 Me CO 2 Et CO 2 -n-Bu CO 2 -t-Bu Ph Pd(0)-Ligand (9) CO 2 Me CO 2 Et CO 2 -n-Bu CO 2 -t-Bu Ph Pd(0)-SR (8) CO 2 Me CO 2 Et CO 2 -n-Bu CO 2 -t-Bu Ph Pd(II)=1 × mole ; Pd(0) = 2.34 × mole ; reactant 1 = reactant 2 = 0.01 mole ; temp. = 115 ℃ ; solvent = DMSO (1 mL) ; base = NEt 3 ( 1.5 mL) ; a cat. = Total Pd(0) + Pd(II) ; b cat. = Surface Pd(0) + Pd(II)

55 RCat. Yield （％） TOF a TOF b CO 2 -n-Bu Pd(0)-ligand-Pd(II)Cl 2 (10) Pd(0)-SR (8) Pd(0)-SR + (6) HO(CH2) 11 N(H)(O)P(2-py) 2 PdCl 2 (6) n.d. 0 0 PdCl 2 (CH 3 CN) 2 n.d. 0 0 PdCl 2 (CH 3 CN) 2 c Pd(II)=1 × mole ; Pd(0) = 2.34 × mole ; reactant 1 = reactant 2 = 0.01 mole ; temp. = 115 ℃ ; solvent = DMSO (1 mL) ; base = NEt 3 ( 1.5 mL) ; a cat. = Total Pd(0) + Pd(II) ; b cat. = Surface Pd(0) + Pd(II) ; c Pd(II)=1 × mole

56 RCat. Times of total substrates and cat. Yield （％） TOF CO 2 -n- Bu PdCl 2 (CH 3 CN) 2 1 ×n.d.0 2 ×2 × × HO(CH2) 11 N(H)(O)P(2-py) 2 PdCl 2 (6) 1 ×n.d.0 2 ×2 × ×3 ×85063 Pd(0)-SR + (6)3 ×3 × a Pd(0)-ligand-Pd(II)Cl 2 (10)3 ×3 × a Pd(0)-ligand-Pd(II)Cl 2 (10) (cat. in xylene for heterogeneous catalyses ) 1 ×1 ×5391 a Pd(0)-ligand-Pd(II)Cl 2 (10) (reflux condition ) 1 ×1 × a a cat. = Surface Pd(0) + Pd(II) 3 × : Pd(II)=3 × mole; Pd(0) = 7.02 × mole; reactant 1 = reactant 2 = 0.03 mole ; temp = 115 ℃ ; solvent = DMSO (3 mL); base = NEt3 ( 4.5 mL)

57 Pd(0)-Pd(II)Cl 2 (10) before heating in 115 o C for 1.5 hr Pd(0)-Pd(II)Cl 2 (10) after heating in 115 o C for 1.5 hr

58 Pd(0)-Pd(II)Cl 2 (10) before heating Pd(0)-Pd(II)Cl 2 (10) after heating

59 Pd(0)-Pd(II)Cl 2 (10) before heatingPd(0)-Pd(II)Cl 2 (10) after heating Particle size distribution = 4.57 ± 1.19 nm Particle size distribution = 4.91 ± 1.28 nm

60Conclusion We use biphasic-synthesis method to prepair the surfaces-modifiable TOAB protected Pd NPs. We have developed a method to successfully immobilize molecular Pd(II) complexes catalysts onto the surfaces of Pd NPs. Since the Pd NPs-Pd(II) hybrid catalysts are highly soluble in organic solvents, their structures and reactions could be easily studied by simple solution NMR technique. The Pd NPs-Pd(II) complexes were proven to be highly effective catalysts for a series of Heck reactions.

61 (6) in CDCl3 before catalyze 3-hexyne heating for 1 day in 70 o C (6) in CDCl3 after catalyze 3-hexyne heating for 1 day in 70 o C

62 (6) in CDCl3 before catalyze 3-hexyne heating for 1 day in 70 o C (zoom in) (6) in CDCl3 after catalyze 3-hexyne heating for 1 day in 70 o C (zoom in)

63 文獻實例 : Langmuir 2002, 18, 還原劑還原法

64 The Mechanisms of Heck Reaction by Pd(0) & Pd(II) Cat. Pd(0) Pd(II) Martin, Chem. Eur. J. 2001, 7, 8,

65 The Proposed Mechanism of Heckfor The Proposed Mechanism of Heck for Pd(II) Immobiled on Pd Nanoparticles

66 Tethered Complex on a Supported Metal Catalyst (TCSM Cat.) Angelici, R. J.; Organometallics 1999, 18,

67 IR Spectra of n-Octanethiol & Pd NPs (8) 2853 (ν s CH 2 ) 2922(ν s CH 3 、 ν as CH 2 ) 2956 (ν as CH 3 ) 1462(δs CH 2 、 δas CH 3 ) 1375(δ s CH 3 ) 722(ρ CH 2 )

68 IR Spectra of Ligand(4), Pd Nanoparticles (9) & (10) 2848 (ν s CH 2 ) 2921(ν as CH 2 ) 1575 (py) 1585 (py)

69 entry 鹼相對於離子液 體之當量數 Pd 添加量 (mL) 反應時間 （ hr ） 產率（％）TONTOF 體積、 濃度相 等但絕 對濃度 被稀釋 絕對濃 度相同

70

71 Heck Reaction X=Cl, Br, IZ=COOR, Ph Mizoroki, T. Chem. Soc. Jap., 1971, 44, 581

72 The Development of Heck Reaction Heck, R. F. J. Am. Chem. Soc. 1968, 90, 5518 Heck*, R. F.; Nolley, J. P. J. Org. Chem., 1972, 37, 14 Mizoroki, T. Chem. Soc. Jap., 1971, 44, 581