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Some applications related to Chapter 11 material:

Some applications related to Chapter 11 material: We will see how the kind of basic science we discussed in Chapter 11 will probably lead to good advances in applied areas such as: 1- Design of efficient solar cell dyes based on charge transfer absorption.

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Some applications related to Chapter 11 material:

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  1. Some applications related to Chapter 11 material: We will see how the kind of basic science we discussed in Chapter 11 will probably lead to good advances in applied areas such as: 1- Design of efficient solar cell dyes based on charge transfer absorption. 2- Strongly luminescent materials based on the Jahn-Teller effect.

  2. 1- Design of efficient solar cell dyes based on charge transfer absorption

  3. diimine dithiolate These complexes should have charge transfer from metal or ligand orbitals to the p* orbitals.

  4. CT-band for Pt(dbbpy)tdt Data from: Cummings, S. D.; Eisenberg, R. J. Am. Chem. Soc.1996, 118 1949-1960

  5. X- Chloride X-thiolate dx2-y2 *bpy hv CT to diimine {  (thiolate) + d  (Pt) dxy dxz-yz dxz+-yz dz2 Connick W. B.; Fleeman, W. L. Comments on Inorganic Chemistry, 2002, 23, 205-230  bpy

  6. 70,000 500 450 60,000 400 50,000 (NIR) 350 (UV/VIS) -1 300 cm 40,000 -1 250 -1 , M cm 30,000 e 200 -1 , M 150 e 20,000 100 10,000 50 0 0 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 Wavelength, nm Electronic absorption spectra for dichloromethane solutions of (dbbpy)Pt(dmid), 1, (thin line) and [(dbbpy)Pt(dmid)]2[TCNQ], 3, (thick line) in the UV/VIS region (left) and NIR region (right). Smucker, B; Hudson, J. M.; Omary, M. A.; Dunbar, K.; Inorg. Chem.2003, 42, 4717-4723

  7. By Brian Prascher, Chem 4610 student, 2003 LUMO Clearly a dx2-y2 orbital, not a diimine p* hv HOMO

  8. So the lowest-energy NIR bands are d-d transitions and the LUMO is indeed dx2-y2, not diimine p* MO diagram for the M(diimine)(dithiolates) class!!! dx2-y2 *bpy *bpy dx2-y2 { {  (thiolate) + d  (Pt)  (thiolate) + d  (Pt) dxy dxz-yz dxz+-yz dz2  bpy

  9. WHO CARES!! The above was science, let’s now see a potential application

  10. Solar Energy Conversion • Silicon cells • 10-20 % efficiency • Corrosion • Expensive (superior crystallinity required) • Wide band gap semiconductors (e.g. TiO2; SnO2; CdS; ZnO; GaP): • Band gap >> 1 eV (peak of solar radiation) • Solution: tether a dye (absorbs strongly across the vis into the IR) on the semiconductor • Cheaper!!… used as colloidal particles

  11. Literature studies to date focused almost solely on dyes of Ru(bpy)32+ derivatives ==> Strong absorption across the vis region (Grätzel; Kamat; T. Meyer; G. Meyer; others)

  12. [M(N3)(X)]+Y-where M = Pt(II), Pd(II) or Ni(II); N3=triimine; X = anionic ligand (SCN-, halide, RS-, etc.). ArS- group Y= Cl-, BF4-, TCNQ-

  13. Absorption Spectra of [Pt(tbtrpy)X]+ Y- Complexes • Using ArS- ligands as X shifts the CT absorption to the VIS region. • Using TCNQ- as Y adds NIR absorptions.

  14. 2- Strongly luminescent materials based on the Jahn-Teller effect

  15. 0 0 10 [Au] + (5d10) [Au(PR3)3]+ PR3 Ground-state MO diagram of [Au(PR3)3]+ species, according to the literature: Forward, J.; Assefa, Z.; Fackler, J. P. J. Am. Chem. Soc. 1995, 117, 9103. McCleskey, T. M.; Gray, H. B. Inorg. Chem. 1992, 31, 1734.

  16. By Khaldoon Barakat, Chem 5560 student, 2002 Molecular orbital diagrams (top) and optimized structures (bottom) for the 1A1’ ground state (left) of the [Au(PH3)3]+ and its corresponding exciton (right). Barakat, K. A.; Cundari, T. R.; Omary, M. A.J. Am. Chem. Soc. 2003, 125, 14228-14229

  17. lem= 496 nm lem= 478 nm lem= 772 nm lem= 640 nm [Au(TPA)3]+ QM/MM optimized structures of triplet [Au(PR3)3]+ models. Barakat, K. A.; Cundari, T. R.; Omary, M. A.J. Am. Chem. Soc. 2003, 125, 14228-14229

  18. WHO CARES!! The above was science, let’s now see a potential application

  19. RGB bright emissions in the solid state and at RT are required for a multi-color device….

  20. AuL3 as LED materials? • Glow strongly in the solid state at RT. • But [Au(PR3)3]+ X- don’t sublime into thin films (ionic). • How about neutral Au(PR3)2X?: • Do they also luminesce in the solid state at RT? • Do they also exhibit distortion to a T-shape?

  21. T-shape and BEYOND! Au(PPh3)2Cl. Bond angles shown are: B3LYP; HF (exptl.). “Photocrystallography” and time-resolved EXAFS should tell us if these distortions toward and beyond a T-shape will really take place experimentally…stay tuned!

  22. * The lifetime (7.9ms) suggests that the emission is phosphorescence from a formally triplet excited state.

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