1 Tetrachelate Porphyrin Chromophores for Metal Oxide Semiconductor Sensitization: Effect of the Spacer Length and Anchoring Group Position Speaker ：李光凡 Jonathan Rochford, Dorothy Chu, Anders Hagfeldt, and Elena Galoppini J. Am. Chem. Soc. 2007, 129,

2 Photoinduced Electron Transfer from Molecules to Semiconductor Nanoparticles Lian, T. Coord. Chem. Rev. 2004, 248, 1231.

3 Different Ways of Anchoring Molecules on Surfaces Grätzel, M. Coord. Chem. Rev. 1998, 177, 347

4 Structures of Dyes Durrant, J. R. J. Am. Chem. Soc. 2004, 126, 5225.

5 Work Principle of DSSCs Grätzel, M. Inorg. Chem. 2005, 44, 6841.

6 “Rigid-rod” and “Tripodal” J. Phys. Chem. B, 2004, 108, J. Phys. Chem. B, , J. AM. CHEM. SOC. 2002, 124,

7 Structures of The Porphyrins Sanders, J. J. Chem.Soc. Chem. Commun. 1991, [E] -[A] -[S]

8 Synthesis of the Porphyrin Sensitizers rt 12h 22-30% 86-92% 68-82% 68-76% rt 12h rt 3 days rt 3h

9 Synthesis of 4a Sonogashira coupling reaction

10 FT-IR-ATR Spectra of p-ZnTCPP and m-ZnTCPP v(C=O) v(C-O) asymmetric v(CO 2 - ) symmetric v(CO 2 - ) v(C=O) symmetric v(CO 2 - ) N + - H bending 10

11 FT-IR-ATR Spectra of m-ZnTCP 2 P and m-ZnTC(PEP)P v(C=O) v(C-O) asymmetric v(CO 2 - ) v(C=O) symmetric v(CO 2 - ) v(C≡C) N + -H bending 11

12 Main Binding Modes of The Carboxylate Group to TiO 2 η1-η1- κ2-κ2-μ2-μ2-

13 Solution UV-Vis Absorption and Fluorescence Emission Data UV-vis absorptionfluorescence porphyrin Soret λ max, nm (ε × 10 5, M -1 L -1 ) Q(1,0) λ max, nm (ε × 10 4, M -1 L -1 ) Q(0,0) λ max, nm (ε × 10 4, M -1 L -1 ) λ max, nm (Φ ) (1e) p-ZnTCPP-[S]424 (2.78)557 (1.39)597 (0.53)606, 658 (0.023) (2e) m-ZnTCPP-[S]423 (4.44)558 (2.09)597 (0.66)604, 657 (0.016) (3e) m-ZnTCP2P-[S]424 (5.51)558 (2.77)597 (0.96)605, 659 (0.017) (4e) m-ZnTC(PEP)P-[S]425 (5.93)558 (2.63)598 (0.83)604, 659 (0.018)

14 UV-vis Spectra and Fluorescence Emission Spectra of 1e 、 2e 、 3e 、 4e λ exc = 565 nm

15 UV-vis Spectra of 1e 、 2e 、 3e 、 4e on TiO 2 /G Thick ~ 10μm

16 UV-vis Absorption Spectra of 1d 、 2d 、 3d 、 4d and 1e 、 2e 、 3e 、 4e on ZnO/G Thick ~ 2μm

17 Fluorescence Emission Spectra of 1e 、 2e 、 3e 、 4e on ZrO 2 /G λ exc = 565 nm E bg ~ 5 eV for ZrO 2 E bg ~ 3 eV for TiO 2 and ZnO

18 Surface Coverage Coverage p-ZnTCPP-[S] 27 μ mol g -1 m-ZnTCPP-[S] 20 μ mol g -1 m-ZnTCP2P-[S] 19 μ mol g -1 m-ZnTTC(PEP)P-[S] 12 μ mol g -1

19 Calculated Molecular Dimensions of p-TCPP 19

20 Calculated Molecular Dimensions of m-ZnTCPP, m-ZnTCP 2 P, and m-ZnTC(PEP)

21 Solution Redox Potentials of 1c 、 2c 、 3c 、 4c in CH 2 Cl 2 oxidation (V)reduction (V) porphyrin1st2nd1st2nd3rdE 0-0 (eV)E 1/2 (P + /P*) (eV) (1c) p-ZnTCPP-[E] (2c) m-ZnTCPP-[E] (3c) m-ZnTCP2P-[E] (4c) m-ZnTC(PEP)P-[E]

22 CV and DPV of 4c and 4e

23 Redox Potentials of 1e 、 2e 、 3e 、 4e Bound to TiO 2 /ITO and ZnO/ITO Films versus NHE TiO 2 /ITO (V)ZnO/ITO (V) porphyrin1st2nd E 0-0 (eV) E 1/2 (P + /P*) (eV) 1st2nd E 0-0 (eV) E 1/2 (P + /P*) (eV) (1e) p-ZnTCPP-[S] (2e) m-ZnTCPP-[S] (3e) m-ZnTCP2P-[S] (4e) m-ZnTC (PEP)P-[S]

24 Photocurrent Action Spectra of 1e 、 2e 、 3e 、 4e FTO = fluorine-doped tin-oxide 59% 19%

25 Photoelectrochemical Properties of 1e 、 2e 、 3e 、 4e IPCE (%) porphyrinI sc (mA cm -2 )V oc (V)ff430 nm570 nm600 nm (1e) p-ZnTCPP-[S] (0.08)0.86 (0.05) (2e) m-ZnTCPP-[S] (0.50)16.30 (0.28) (3e) m-ZnTCP2P-[S] (0.61)21.10 (0.37) (4e) m-ZnTC(PEP)P-[S] (0.36)4.81 (0.19) IPCE = (LHE) ψ inj η c LHE:light harvesting efficiency ψ inj :the quantum yield of charge injection ηc :the charge collection efficiency

26 Conclusions Four para- and meta-Zn(II) tetra(carboxyphenyl)porphyrins were studied in solution and bound to metal oxide (TiO 2, ZnO, and ZrO 2 ) nanoparticle films to determine the effect of the spacer length and anchoring group position on their photoelectrochemical and photophysical properties. All studies indicated that only p-ZnTCPP aggregated, suggesting close packing of the dye molecules on the semiconductor surface, and aggregation effects were not observed for the meta porphyrins. The greater efficiency of the rigid planar meta-substituted systems was explained in terms of a greater charge injection into the TiO 2 semiconductor from rings that lie flat, and closer, to the surface.