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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

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
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
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
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
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
Whitesides

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

Emmanuel Nicolas

bite angle influence
Bite Angle Influence

Halpern

Emmanuel Nicolas

bite angle influence1
Bite Angle Influence

Whitesides

Halpern

Emmanuel Nicolas

bite angle influence2
Bite Angle Influence

Whitesides

Halpern

Emmanuel Nicolas

our strategy
Our Strategy

Whitesides

Halpern

Emmanuel Nicolas

our strategy1
Our Strategy

Whitesides

Halpern

Chemistry

with Pt(0)

Chemistry

with Pt(II)

Emmanuel Nicolas

synthesis of dcpp ptx 2
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 ptx 2
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 ptx 21
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 ptx 22
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 c 7 h 7
[(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
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 study disappearance of pt d in c 6 h 6
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
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
“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 c 7 h 7
Stability of [(DCPP)Pt(H)(C7H7)]

Leaving complex in toluene for days

Dimer cristallizes

Emmanuel Nicolas

dihydride dimer
Dihydride Dimer

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

Emmanuel Nicolas

further reactivity arene coupling
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
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 rationalization1
DFT Rationalization

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

Emmanuel Nicolas

dft rationalization2
DFT Rationalization

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

Emmanuel Nicolas

dft rationalization3
DFT Rationalization

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

Emmanuel Nicolas

conclusion
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
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