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Room Temperature C-H Activation with Pt(0)

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

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Room Temperature C-H Activation with Pt(0)

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  1. Room Temperature C-H Activation with Pt(0) Emmanuel Nicolas Lab “Hétéroéléments et Coordination” Ecole Polytechnique Palaiseau, France

  2. 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

  3. 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

  4. Problem position • Drastic conditions • High Temperature • High pressure • Long reaction times • Increase electron density at metal to ease bond activation  Reduced metals Emmanuel Nicolas

  5. 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

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

  7. Bite Angle Influence Halpern Emmanuel Nicolas

  8. Bite Angle Influence Whitesides Halpern Emmanuel Nicolas

  9. Bite Angle Influence Whitesides Halpern Emmanuel Nicolas

  10. Our Strategy Whitesides Halpern Emmanuel Nicolas

  11. Our Strategy Whitesides Halpern Chemistry with Pt(0) Chemistry with Pt(II) Emmanuel Nicolas

  12. 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

  13. 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

  14. 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

  15. 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

  16. [(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

  17. 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

  18. Kinetic StudyDisappearance of Pt-H in C6D6 1H Emmanuel Nicolas

  19. 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

  20. 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

  21. “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

  22. Stability of [(DCPP)Pt(H)(C7H7)] Leaving complex in toluene for days Dimer cristallizes Emmanuel Nicolas

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

  24. 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

  25. 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

  26. DFT Rationalization ω-B97X-D // Def2-TZVP (Pt) // 6-31G* (P/C/H) // 6-311+G** (mobile H) Emmanuel Nicolas

  27. DFT Rationalization ω-B97X-D // Def2-TZVP (Pt) // 6-31G* (P/C/H) // 6-311+G** (mobile H) Emmanuel Nicolas

  28. DFT Rationalization ω-B97X-D // Def2-TZVP (Pt) // 6-31G* (P/C/H) // 6-311+G** (mobile H) Emmanuel Nicolas

  29. 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

  30. 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

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