Lorenzo Zani Brief CV and Research Interests - CNR · 2013-09-25 · Solar Cells Lorenzo Zani – CNR ISOF – 11/06/2012 D-π-A structure: DONOR GROUP ACCEPTORπ GROUP Ideal Properties

Lorenzo Zani – CNR ISOF – 11/06/2012

2002 «Laurea» in Chemistry – University of Florence (Italy)

2003-2006 Ph. D. in Chemistry – RWTH Aachen University (Germany) Supervisor Prof. C. Bolm Asymmetric Synthesis, Metal-catalyzed Reactions

2007-2008 Post-Doc – Stockholm University (Sweden) Supervisor Prof. H. Adolfsson Asymmetric Synthesis, Metal-catalyzed Reactions

2009-2010 Post-Doc – The Institute of Cancer Research (United Kingdom) Supervisor Prof. K. Jones Heterocyclic Synthesis, Medicinal Chemistry

2010-2011 Post-Doc – CNR-ICCOM (Italy) Supervisor Dr. G. Reginato Development of Photoelectrochemical Solar Cells (DSSC)

2011-present Researcher – CNR-ISOF (Italy) Development of DSSC, Synthetic Methodology

Lorenzo Zani – Brief CV and Research Interests

1/17

Asymmetric Addition of Organozinc Reagents to Aldehydes and Imines

Asymmetric Synthesis of Diarylmethanols


Precursors of active pharmaceutical

ingredients

Diarylmethanols

J. Org. Chem. 2006, 71, 2320

2/17

Asymmetric Addition of Organozinc Reagents to Aldehydes and Imines

One-pot Asymmetric Synthesis of Propargylamines


Extension of a known procedure to the preparation of new compounds

- Ligand optimization - Variation of the reaction conditions - Development of analytical methods

Chem. Eur. J. 2007, 13, 2587

3/17

Metal-catalyzed Reductions of Carbonyl Compounds

Enantioselective Transfer Hydrogenation (ETH) of Acetophenones


ETH of ketones is a well-established methodology to obtain enantiomerically enriched secondary alcohols:

Testing of new metal-ligand combinations:

[Ru] + chiral sulfinamides (stereogenic center on sulfur)

Use of a sulfonamide analogue (not having a stereogenic center

on sulfur) resulted in the formation of a racemic product!

Eur. J. Org. Chem. 2008, 4655

4/17

Metal-catalyzed Reductions of Carbonyl Compounds

Iron-catalyzed hydrosilylation of ketones


Use of silanes as reducing agents allows a mild and chemoselective conversion of ketones to alcohols:

- Use of abundant, cheap and non-toxic metal precursors

- In situ catalyst preparation, simple and mild procedure and work-up

Fe-NHC complexes

Appl. Organomet. Chem. 2011, 25, 748

5/17

Discovery of New Inhibitors of Chaperone Proteins


- Heat shock proteins (Hsp) are ubiquitous and highly conserved proteins, occurring in all cellular organisms.

- Hsp main role is to act as molecular chaperones which bind to unfolded proteins, either nascent polypeptides or denatured ones, facilitating their refolding to the native state.

- Hsp proteins are classified based on their molecular weight. Two of the main chaperone families are Hsp70 and Hsp90.

- Cancer cells are crucially dependent on chaperone protein function as they are a hot-house of protein synthesis and replication. Therefore, chaperones are promising molecular targets for cancer treatment.

Above: Structure of the Hsp90 molecular chaperone Below, right: Structure of the Hsp70 molecular chaperone Below, left: NVP AUY-922, an Hsp90-inhibitor currently in phase II clinical trials

In collaboration with:

6/17

Solar Energy and Photovoltaic Cells

PM.P04.012 – Design, sintesi e test di molecole e materiali per celle solari fotosensibilizzate Responsible: Dr. Filippo de Angelis (ISTM, Perugia)

Modulo: PM.P04.012.003 – Sintesi di nuovi sensibilizzatori con sistemi di ancoraggio ottimizzabili Responsible: Dr.ssa Gianna Reginato (ICCOM, Florence)

- Participation to an active CNR project

Lorenzo Zani – CNR ISOF – 11/06/2012 7/17

May 2010 – Nov 2011:

- FOTOSENSORG Project: «Design and synthesis of novel organic sensitizers for non-conventional photovoltaic cells» (research grant)

CNR-ICCOM

Supervisor: Dr.ssa Gianna Reginato

Università degli Studi di Siena Supervisor: Prof. Maurizio Taddei

Nov 2011 – present:

http://www.cnr.it/commesse/Scheda_Commessa.html?id_comm=7692




http://www.cnr.it/commesse/Scheda_Modulo.html?id_mod=7729





Solar Energy and Photovoltaic Cells


Photovoltaic Cell: a device able to convert light into electrical power

Main Classes of Photovoltaic Cells

1) Silicon Cells

a) Monocrystalline silicon cells

b) Polycrystalline silicon cells

2) Thin Film Solar Cells

a) GaAs

b) CdTe

c) CI(G)S – CuIn(Ga)Se2

d) Amorphous silicon (a-SiH)

3) Organic and Hybrid Photovoltaics

a) Bulk Heterojunction Solar Cells

b) Dye-Sensitized Solar Cells (DSSC)

8/17


Photovoltaic Cells: Hystorical Development

9/17

Cell efficiency: η = Pmax / Pin

Dye-Sensitized Solar Cells


Michael Grätzel G24i (UK)

Sony (Japan)

- Invented by Michael Grätzel at EPF in Lausanne (Switzerland) in 1991 (B. O’Regan, M. Grätzel, Nature 1991, 353, 737).

- High efficiency under optimized conditions: ηmax > 12% (lab scale).

- Readily available raw materials, simple and inexpensive production process.

- Relatively insensitive towards illumination conditions (angle, intensity, temperature).

- They can be built using flexible substrates.

- They can be transparent or opaque, and can be produced in different colours (important for BIPV).

10/17


Platinum

Electrolyte Solution (I-/I3

-)

TiO2 Dye

Transparent Conductive

Oxide

Glass

Glass

Components

1. Glass substrate

2. TCO (Transparent Conductive Oxide) layer

3. Nanocrystalline semiconductor (TiO2)

4. Dye (adsorbed on the semiconductor)

5. Electrolyte solution containing a redox couple

6. Counterelectrode (usually made of Pt)

7. Glass substrate


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Mechanism

1. Light absorption

2. Photoexcitation

3. Injection

4. Charge collection

5. Regeneration

6. Electrolyte oxidation

Transition metal complexes

Organic Compounds

Porphirins

Dye


12/17

Development of New Organic Dyes for Dye-Sensitized Solar Cells


DONOR GROUP ACCEPTOR GROUP D-π-A structure:

Ideal Properties of a DSSC Dye:

a) Broad and efficient light absorption in the visible and near-infrared region.

b) Should have functional groups allowing a good anchoring on TiO2 (-COOH, -PO3H2, -SO3H).

c) Its energy levels should be correctly aligned to ease regeneration and electron injection.

d) It should not aggregate on the surface of the semiconductor.

e) It should be thermally, chemically and photochemically stable.

-SPACER π

13/17

Also responsible of anchoring

to TiO2

Gem-Silanediol Anchoring Group


- Form strong bonds with metal oxides

- Could be used to build long-lasting DSSCs

photovoltaic performances still unsatisfactory, must be

improved (stronger EWG group?)

UV-Vis absorption spectra of 8a-b and 9a-b in ethanol solution.

Cyclic voltammetry (semiderivative plot) of 8b and 9b in CH2Cl2 solution.

14/17

Fused-Thiazole Heterocycles as Conjugate Spacers


- Previously employed in OPV but not in DSSCs

- Oxidative and thermal stability

- High charge carrier mobility

- Good light absorption properties

- Thiazolothiazole unit weak EWG

TD-DFT calculations suggest that these compounds are suitable for employment in DSSCs.

15/17

Fused-Thiazole Heterocycles as Conjugate Spacers


UV-Vis absorption spectra of 13 in methanol (●) and CH2Cl2 (▼), and emission spectrum in methanol (○).

Cyclic (full) and Osteryoung square wave (dashed) voltammograms recorded of a CH2Cl2 solution of 13.

Under illumination (―)

Dark (---) J-V characteristic of a DSSC built using 13 as the sensitizer. Main photovoltaic parameters: Voc = 712 mV; Jsc = 7.0 mA/cm2; ff = 0.67; η = 2.5%.

16/17

Dye-Sensitized Solar Cells: Outlook


- Measurement and optimization of the photovoltaic performances of all new compounds (8, 9, 14, 15).

- Synthesis and application of new DSSC dyes having different anchoring/acceptor units.

- Exploration of alternative anchoring mechanisms (semiconductor functionalization).

- Start investigations on novel (metall)organic redox couples and electrolyte compositions.

17/17

Documents

Lorenzo Zani Brief CV and Research Interests - CNR · 2013-09-25 · Solar Cells Lorenzo Zani – CNR ISOF – 11/06/2012 D-π-A structure: DONOR GROUP ACCEPTORπ GROUP Ideal Properties