1. Bipyridyl Pt(II) Bisstilbenylacetylide: Synthesis, Photophysics, and Nonlinear Transmission
Zhongjing Li
Advisor: Professor Wenfang Sun
Department of Chemistry and Biochemistry
North Dakota State University

2. Research Background Intense interest in Pt(II) complexes
Unique photophysical properties
OLED, DNA intercalator, solar cells, photocatalysis, nonlinear optical materials
Pt(II) diimine bis(arylacetylide) complexes
Metal-to-ligand charge-transfer emissive state
HOMO and LUMO tuned by structure modification
Large σEX/σ0 in the visible region and large σTPA in the near-IR region
Eisenberg, R. Inorg. Chem. 2000, 39, 447.
Schanze, K. S. Inorg. Chem. 2001, 40, 4053.
Castellano, F. N. Inorg. Chem. 2003, 42, 1394.
Sun, W. Chem. Mater. 2010, 122, 6384.

3. Bipyridyl Pt(II) Bisstilbenylacetylide
Combine the two photon absorption of stilbene with the excited-state absorption of platinum acetylide complex to obtain materials with broadband nonlinear absorption
Understand the effect of the substituent at the stilbene on the photophysics and nonlinear absorption of the complexes

5. Electronic Absorption

6. Ground-state MO Energy Diagram

7. Photoluminescence

8. Transient Absorption Sample 1 2 3 4 5 6 T (ns) 401 225 48 64 73 198
εT (M-1*cm-1)
9.88104
1.85105
2.36105 ΦT
0.13
0.06

10. Nonlinear Absorption

12. Two-Photon Absorptions
Unpublished results
Two-Photon Absorptions

13. Summary The lowest-energy absorption bands and emission:
Dominated by the MLCT/LLCT with an admixture of the π,π* character in 3−5
Dominated by the ligand-centered π,π* with the admixture of MLCT/LLCT characters in 1, 2, and 6
Strong ns and fs TA in the visible spectral region from stilbene-localized π,π* state with the double bond in the trans geometry
Broad and extend to the near-IR region for 1 and 2: contribution from the acetylide ligand cation
Strong RSA for the ns laser pulse at 532 nm, with complex 6 showing the strongest RSA

14. Future Research
Platinum complexed based on cyclometallated tri-dentate ligands
Iridium complexes