Room temperature c h activation with pt 0
Download
1 / 30

Room Temperature C-H Activation with Pt(0) - PowerPoint PPT Presentation


  • 111 Views
  • Uploaded on
  • Presentation posted in: General

Room Temperature C-H Activation with Pt(0). Emmanuel Nicolas Lab “Hétéroéléments et Coordination” Ecole Polytechnique Palaiseau , France. C-H Activation With Pt(II)/Pt(IV). A. Shilov et al. ; Russ. J. Phys. Chem., USSR 1969 , 43 , 1222

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha

Download Presentation

Room Temperature C-H Activation with Pt(0)

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Room Temperature C-H Activation with Pt(0)

Emmanuel Nicolas

Lab “Hétéroéléments et Coordination”

Ecole Polytechnique

Palaiseau, France


C-H Activation With Pt(II)/Pt(IV)

A. Shilovet al.; Russ. J. Phys. Chem., USSR1969, 43, 1222

R. A. Perianaet al., Science1998, 280, 560–564

  • Shilov: System

    • 120 °C

  • Periana: CatalyticaTM System

    • 34 bars, 180 °C, 2.5 hours

  • Emmanuel Nicolas


    C-H Activation with Rh/Ir

    J. Hartwiget al., J. Am. Chem. Soc.2005, 127, 2538–52

    M. Brookhart, A. Goldman et al., Nature Chem.2011, 3, 167–71

    Hartwig: Rh

    Brookhart and Goldman: Ir

    Emmanuel Nicolas


    Problem position

    • Drastic conditions

      • High Temperature

      • High pressure

      • Long reaction times

    • Increase electron density at metal to ease bond activation

       Reduced metals

    Emmanuel Nicolas


    Halpern: Pt(0)/Pt(II)

    Abis, L.; Sen, A.; Halpern, J. J. Am. Chem. Soc.1978, 100, 2915–6

    • [(PPh3)2PtHMe]

      • Stable up to -50°C

      • Eliminates Methane above -25°C

    Emmanuel Nicolas


    Whitesides

    Hackett, M.; Ibers, J. A.; Jernakoff, P.; Whitesides, G. M. J. Am. Chem. Soc.1986, 108, 8094–5

    Emmanuel Nicolas


    Bite Angle Influence

    Halpern

    Emmanuel Nicolas


    Bite Angle Influence

    Whitesides

    Halpern

    Emmanuel Nicolas


    Bite Angle Influence

    Whitesides

    Halpern

    Emmanuel Nicolas


    Our Strategy

    Whitesides

    Halpern

    Emmanuel Nicolas


    Our Strategy

    Whitesides

    Halpern

    Chemistry

    with Pt(0)

    Chemistry

    with Pt(II)

    Emmanuel Nicolas


    Synthesis of [(DCPP)PtX2]

    Overall Yield: 97%

    Issleib, K.; Müller, D.-W. Chem. Ber.1959, 92, 3175–3182

    McDermott, J. X.; White, J. F.; Whitesides, G. M. J. Am. Chem. Soc.1976, 98, 6521–8.

    Emmanuel Nicolas


    Reduction of [(DCPP)PtX2]

    31P{1H}

    Davies, J. A.; Staples, R. J. Polyhedron1991, 10, 909–917.

    Nicolas, E.; le Goff, X.-F.; Bouchonnet, S.; Mézailles, N. Chem. Comm.2012, 48, 8350–2.

    Emmanuel Nicolas


    Reduction of [(DCPP)PtX2]

    1H

    Davies, J. A.; Staples, R. J. Polyhedron1991, 10, 909–917.

    Nicolas, E.; le Goff, X.-F.; Bouchonnet, S.; Mézailles, N. Chem. Comm.2012, 48, 8350–2.

    Emmanuel Nicolas


    Reduction of [(DCPP)PtX2]

    Davies, J. A.; Staples, R. J. Polyhedron1991, 10, 909–917.

    Nicolas, E.; le Goff, X.-F.; Bouchonnet, S.; Mézailles, N. Chem. Comm.2012, 48, 8350–2.

    Emmanuel Nicolas


    [(DCPP)PtH(C7H7)]

    P-Pt-P: 87.16°

    Nicolas, E.; le Goff, X.-F.; Bouchonnet, S.; Mézailles, N. Chem. Comm.2012, 48, 8350–2

    Hackett, M.; Ibers, J. A.; Jernakoff, P.; Whitesides, G. M. J. Am. Chem. Soc.1986, 108, 8094–5

    Emmanuel Nicolas


    Exchange Reactions

    At room temperature, aryl exchanges statistically with the solvent

    Nicolas, E.; le Goff, X.-F.; Bouchonnet, S.; Mézailles, N. Chem. Comm.2012, 48, 8350–2.

    Emmanuel Nicolas


    Kinetic StudyDisappearance of Pt-H in C6D6

    1H

    Emmanuel Nicolas


    Kinetic StudyDisappearance of Pt-D in C6H6

    31P{1H}

    Integration of part of P-Pt-D coupling motif againstsum of Pt-H and Pt-D

    Emmanuel Nicolas


    Thermochemistry

    k-H= 0.054 L.mol-1.h-1

    k-D= 0.12 L.mol-1.h-1

    Nicolas, E.; le Goff, X.-F.; Bouchonnet, S.; Mézailles, N. Chem. Comm.2012, 48, 8350–2.

    Emmanuel Nicolas


    “Pt(0)” species

    Nicolas, E.; le Goff, X.-F.; Bouchonnet, S.; Mézailles, N. Chem. Comm.2012, 48, 8350–2.

    Room-temperature equilibrium between Pt(II) and Pt(0) species

    Emmanuel Nicolas


    Stability of [(DCPP)Pt(H)(C7H7)]

    Leaving complex in toluene for days

    Dimer cristallizes

    Emmanuel Nicolas


    Dihydride Dimer

    Nicolas, E.; le Goff, X.-F.; Bouchonnet, S.; Mézailles, N. Chem. Comm.2012, 48, 8350–2.

    Emmanuel Nicolas


    Further reactivity – Arene coupling

    GC/MS Study: Stéphane Bouchonnet, DCMR, Ecole Polytechnique, France

    • Heating in Toluene

    • Biphenyl derivatives detected by GC/MS

      • Mixture of isomers

    Emmanuel Nicolas


    DFT Rationalization

    Benzeneis a reagent and the solvent

     ConsiderΔH ratherthanΔG

    ω-B97X-D // Def2-TZVP (Pt) // 6-31G* (P/C/H) // 6-311+G** (mobile H)

    Emmanuel Nicolas


    DFT Rationalization

    ω-B97X-D // Def2-TZVP (Pt) // 6-31G* (P/C/H) // 6-311+G** (mobile H)

    Emmanuel Nicolas


    DFT Rationalization

    ω-B97X-D // Def2-TZVP (Pt) // 6-31G* (P/C/H) // 6-311+G** (mobile H)

    Emmanuel Nicolas


    DFT Rationalization

    ω-B97X-D // Def2-TZVP (Pt) // 6-31G* (P/C/H) // 6-311+G** (mobile H)

    Emmanuel Nicolas


    Conclusion

    A stable Pt(II) complex, source of Pt(0) at room temperature has been synthesized.

    Chemistry at Pt(0) and Pt(II) is possible with this complex

    Furtherstudiesconcerningretrieval of Pt(0) from Pt hydride dimer are underway

    Emmanuel Nicolas


    Acknowledgments

    PhD Advisor:

    Dr. Nicolas Mézailles

    GC/MS Studies:

    Dr. Stéphane Bouchonnet (DCMR)

    X-Ray Structures:

    Dr. Xavier Le Goff

    Dr. Louis Ricard

    Funding:

    PhoSciNet

    CNRS

    Ecole Polytechnique (fellowship)

    N. Mézailles has an open Ph.D. position for a non-French student within the SusPhos program.

    Emmanuel Nicolas


    ad
  • Login