Simona Fantacci

1. Spectroscopy of d6Ru and Ir polypyridyl complexes for solar cells, OLED and NLO applications: Insights from theory Simona Fantacci Istituto CNR di Scienze e Tecnologie Molecolari (ISTM-CNR) & UdR INSTM Perugia Dipartimento di Chimica Via Elce di Sotto, 8, Perugia, 06123 - ITALY

2. Methodology Overview G03(B3LYP/DVZP), ADF(TZP,BP86) Car-Parrinello (PBE//PWs) • Computational approach • Geometry Optimizations (CP-ultrasoft pseudopotentials) • Calculation of excited states energies and oscillator strengths by Time Dependent-DFT (G03, ADF) • Inclusion of solvation effects by a Polarizable Continuum Model (PCM) (G03, CP, ADF) Spectroscopic properties of Ru- and Ir- complexes: a)S. Fantacci, F. De Angelis, A. SelloniJ. Am. Chem. Soc. 2003, 125, 4381. b)F. De Angelis, S. Fantacci, A. SelloniChem. Phys. Lett. 2004, 389, 204. c)S. Fantacci, F. De Angelis,..., A. SelloniJ. Am. Chem. Soc. 2004, 126, 9715. d)F. De Angelis, A. Tilocca, A. SelloniJ. Am. Chem. Soc. 2004, 126, 15024. e)S. Fantacci, F. De Angelis, A. Sgamellotti,...J . Am. Chem. Soc. 2005. 127, 14144. f)M. K. Nazeeruddin, F. De Angelis, S. Fantacci,... J. Am. Chem. Soc. 2005. 127, 16835. g)F. De Angelis, S. Fantacci, A. Selloni, M. K. NazeeruddinChem. Phys. Lett. 2005,415, 115. h)F. Tessore, D. Roberto,..., R. Ugo, F. De Angelis Inorg. Chem. 2005, 44, 8967. i)F. De Angelis, S. Fantacci, A. Sgamellotti,.., R. Ugo Dalton Trans. 2005, 2006, 852. l)C. Barolo, M.K. Nazeeruddin, S. Fantacci,… M. Grätzel Inorg. Chem. 2006, 45, 4642. m) M.K. Nazeeruddin,… F. De Angelis, S. Fantacci, M. GrätzelInorg. Chem. 2006, 45, 9245. n) F. De Angelis, S. Fantacci,... M. Grätzel, M.K. NazeeruddinInorg. Chem. 2007, 46, in press. o) C. Dragonetti,… R. Ugo, F. De Angelis, S. Fantacci, A. Sgamellotti …Inorg. Chem.2007, 46, in press.

3. Ru(II)-polypyridyl sensitizers for TiO2 in dye sensitized solar cells (DSSCs) • The dye, adsorbed on the semiconductor oxide surface, absorbs light in the visible region. • An electron is then transferred from the dye excited state to the TiO2 conduction band. • The oxidized dye is regenerated by a support electrolyte. [Ru(4,4’COOH2,2’bpy)2(NCS)2], defined as N3 An efficient solar cell sensitizer should have broad range of visible light absorption, form long-living excited states with energies almost matching those of the TiO2conduction band and show a high thermal stability. M. Graetzel, Nature, 2001, 414, 338.; M. GraetzelInorg. Chem. 2005, 44, 6841

4. N3 N621 N34- N945 N866 Cl Tuning the properties of Ru(II) TiO2 sensitizers Effect of deprotonation and ligand substitution Bypyridine functionalization Ligand engineering

5. Experimental and calculated absorption spectra of N3 in water solution * Intensity (arb. units) MLCT (II) Exp. Theor. MLCT (I) Energy (eV) LUMO HOMO-3 HOMO (III) ethanol water S. Fantacci, F. De Angelis, A. SelloniJ. Am. Chem. Soc. 2003, 125, 4381. F. De Angelis, S. Fantacci, A. SelloniChem. Phys. Lett. 2004, 389, 204. Md. K. Nazeeruddin, F. De Angelis,.. , M. Grätzel J. Am. Chem. Soc. 2005, 127, 16835.

6. Modeling of TiO2 surface Stoichiometric anatase Ti38O76 cluster of nanometric dimensions exposing (101) surfaces B3LYP/3-21g* (NEQ-PCM) TD-DFT gap in solution: 3.20 eV KS gap in solution: 3.78 eV TD-DFT gap in vacuo: 2.82 eV KS gap in vacuo: 3.48 eV Experimental gap in acqueous solutions: 3.20 – 3.30 eV F. De Angelis, A. Tilocca, A. SelloniJ. Am. Chem. Soc. 2004, 126, 15024.

7. Car-Parrinello molecular dynamics simulation of N3 adsorption on TiO2 surface Starting from the final configuration we performed local geometry optimizations placing the protons on different sites.

8. 0.0 kcal/mol +11.0 kcal/mol 1 2 3 4 1H+ on dye / 1H+ on TiO2 1H+ on dye / 1H+ on TiO2 +9.9 kcal/mol 0H+ on dye / 2H+ on TiO2 1H+ on dye / 3H+ on TiO2

9. Simulation of the Absorption spectrum Md. K. Nazeeruddin, R. Humphry-Baker, P. Liska, M. Grätzel, J. Phys. Chem. B,2003, 107, 8981. Md. K. Nazeeruddin, F. De Angelis, S. Fantacci..,M. GrätzelJ. Am. Chem. Soc., 2005, 127, 16845.

10. Ir(III)-polypyridyl complexes as phosphorescent dyes for OLED and NLO X=NMe2 [Ir(ppy)2(5-X-1,10-phen)]+ High transparency in the visible region and high NLO response (βEFISH>2000 10-30esu) Strong and tunable emission in the visible region (600-450 nm) Φmax=85% X=NO2

11. Phosphorescent Ir(III) complexes for OLED phenylpyridine-phenanthroline (ppy-phen) phenylquinoline-phen X = Me, NMe2, NO2(ppq-phen) M.K. Nazeeruddin, R.T. Wegh, C. Klein, Q. Wang, F. De Angelis, S. Fantacci, M. Grätzel, Inorg. Chem. 2006, 45, 9245. F. De Angelis, S. Fantacci, N. Evans, C. Klein,..., M. Grätzel, M.K. Nazeeruddin Inorg. Chem. 2007, 46, in press. C. Dragonetti, L. Falciola, P. Mussini, S. Righetto, D. Roberto, R. Ugo, F. De Angelis, S. Fantacci, A. Sgamellotti et al.Inorg. Chem.2007, 46, in press.

12. Ir(III) cyclometallated complexes as multifunctional NLO Materials X=NMe2 X=NO2 L+2 L+1 L H H-1 L+2 L+1 L H H-1 X=NO2, NMe2

13. Absorption spectrum, SOS- X=NO2-NMe2 =transition dipole moment =excitation energy ground and excited state dipole moments Positive and negative contributions to  Only negative contributions to  Ir->phen (MLCT) phen-(ILCT) C. Dragonetti, S. Righetto, D. Roberto, R. Ugo, A. Valore, F. De Angelis, S. Fantacci, A. SgamellottiChem. Comm. submitted

14. Conclusions • Theoretical and computational advances allow the study of systems of large and increasing complexity with unprecedented accuracy • Quantitative agreement between theory and experimental optical properties of complex systems • Interpretative and predictive power of modeling Acknowledgments: Prof. Renato Ugo: Ir(III) complexes for OLED and NLO materials Prof. Michael Grätzel: TiO2 Ru(II) photosensitizers and Ir(III) complexes for OLED Dr. Filippo De Angelis: TiO2 calculations and CP simulations