Synthesis of a Ruthenium- Cobalt Synthesis of a Ruthenium- Cobalt Dyad for Photo-Induced Hydrogen Dyad for Photo-Induced Hydrogen

ProductionProductionPresented by: Ibrahim SHALAYELSupervisors: Dr. Damien JOUVENOT Rajaa FARRAN

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Master -1- Internship DCM-CIRe

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• Introduction Demonstration of Concept State of the Art Aim of work

• Results and Discussion Retrosythetic Pathway Functionalization of the Photosensitizer Introduction of the Anchoring groups Functionalization of the Catalyst

• Conclusion

• Perspectives

• Acknowledgement

Content

Earth is Calling Us!

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• Global warming : CO2 emission

• Shortage of fossil fuels

• Clean and renewable energy alternative

• Inspired from photosynthesis « Conversion of solar energy into chemical energy »

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Wake Up to the Power of Sun!

IntroductionDemonstration of Concept

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D Ae-

+

t2g

π* eg

*

Frontier molecular orbitals of a d6 octahedral complex

What is a Charge Separated State ?

H+

H2

H+

e-

Energy Vector

Demonstration of ConceptIntroduction

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State of the Art

Different Cobalt Catalysts

* Carbon Dioxide as a Source of Carbon, Vol. 206), Springer Netherlands, 1987, pp. 113-138.* Chemical Science 2013, 4, 3934-3945.

Angewandte Chemie International Edition 2008, 47, 564-567. The journal of physical

chemistry. B 2010, 114, 14572-14581.

Photocatalysts Based on Cobalt

Introduction

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Objective of the Work

Photosensitizer

Catalyst

Conductive Surface

Covalent Linkage

2H+ H2

e-

e-• Use [Ru(bpy)2(phen)]2+ as a photosensitizer and [Co(bpy2PyMe)L]2+/+ as a catalyst

• Covalently link both subunits

• Introduce Phosphonates to graft on conducting surface

Introduction

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Retrosynthetic Scheme

Coupling ReactionCoupling ReactionNucleophilic Substitution

Results and Discussion

Condensation reaction

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Results and Discussion

Functionalization of the Photosensitizer

Ruthenium complexes are stable and several chemical reaction have

been developed on them

Suzuki

Limitation

Solubility of Ruthenium

Solution

Boronic Ester Triflate

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Results and Discussion

Functionalization of the Photosensitizer

(i) HNO3:H2SO4 (1:2), KBr, 3 h, 100 °C

(ii) 4-bromobenzaldehyde, NH4OAc, acetic acid, 4 h, 100 °C

(iii) [Ru(bpy)2Cl2].2H2O, ethylene glycol, 3 h, 120 °C

(iv) bis(pinacolato)diboron, KOAc, [Pd(dppf).Cl2].2CH2Cl2, DMSO, 14 h, 85 °C

Tetrahedron Letters 1997, 38, 8159-8160Dalton Transactions 2003, 2260-2268.

• 4 steps overall yield for 3 steps 32 %

• Mixture of products which require separation or change of strategy

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Results and Discussion

Introduction of Anchoring Groups

Indium Tin Oxide Surfaces

Transparent

Allow covalent attachements

Conducts electrons

Choice of Surface

Stable towards hydrolysis in

acidic condition

Tridentate binding mode

Form covalent bonds with Tin Oxide

Surfaces

Advantages of Phosphonic Acids

Tetrahedron 2010, 66, 7272-7278.

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Results and Discussion

Introduction of Anchoring Groups

(i) H2SO4, EtOH, 80 h, 78 °C(ii) NaBH4, EtOH, 3 h, 78 °C(iii) HBr:H2SO4 (3:1), 12 h, 100 °C(iv) P(OCH2CH3)3, CHCl3, 12 h, 160 °C(v) [RuCl3].3H2O, DMF, 6 h, 150 °C

• 5 steps overall yield 21 %

• Allylic bromination with NBS yield a mixture of products

• The final product is paramagnetic

Inorganic Chemistry 2001, 40, 6073-6079.

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Functionalization of the CatalystResults and Discussion

•Prevents dissociation during the catalytic cycle and leaves one coordination site available for the exogenous ligands

•Allows the modification of the pyridine at the para position, which could be used for the introduction of spacer.

Interest

Bis(pinacolato)diboron, KOAc, [Pd(dppf).Cl2].2CH2Cl2, DMSO, 14 h, 85 °C

CH3CH2MgBr, PhCO2Cl, THF, 20 min, -78 °C; Toluene, o-chloranil, 24 h, 25 °C

The Journal of Organic Chemistry 1985, 50, 4410-4411

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Results and Discussion

Mechanism

(i) [Pd(PPh3)4], K2CO3, toluene: H2O, 12 h, 110 °C

(i) [Pd(PPh3)4], toluene, 12 h, 110 °C

Functionalization of the Catalyst

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Conclusion

Demonstrated a functionalization pathway for the photosensitizer

Prepared the phosphonate precursor

Synthesized the building block for

the catalyst

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Perspectives

ISOLATE THE DYAD

Full characterization (cyclic voltammetry, UV, MS, electron

transfer kinetics)

Study the Photocatalytic

activity

Photocurrent studies

My deepest appreciation to;

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Dr. Damien JOUVENOTAssistant Prof. at UJF

Rajaa FARRANDoctorant

Dr. Jerôme CHAUVINAssistant Prof. at UJF

Molecular Chemistry Department Laboratory of Redox Inorganic Chemistry

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Achnowledgement

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Thank you for your attention.