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Bipyridyl Pt(II) Bisstilbenylacetylide: Synthesis, Photophysics, and Nonlinear TransmissionZhongjing LiAdvisor: Professor Wenfang Sun

Department of Chemistry and BiochemistryNorth Dakota State University1

Intense interest in Pt(II) complexesUnique photophysical propertiesOLED, DNA intercalator, solar cells, photocatalysis, nonlinear optical materialsPt(II) diimine bis(arylacetylide) complexesMetal-to-ligand charge-transfer emissive stateHOMO and LUMO tuned by structure modificationLarge EX/0 in the visible region and large TPA in the near-IR regionResearch BackgroundEisenberg, 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, 6384.2

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 complexes3

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Electronic Absorption

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Ground-state MO Energy Diagram

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Photoluminescence

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Transient Absorption

Sample123456T (ns) 401225486473198 T (M-1*cm-1)9.881041.851052.36105T0.130.060.068

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Nonlinear Absorption

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Two-Photon Absorptions

Unpublished results12

SummaryThe lowest-energy absorption bands and emission:Dominated by the MLCT/LLCT with an admixture of the ,* character in 35Dominated by the ligand-centered ,* with the admixture of MLCT/LLCT characters in 1, 2, and 6Strong ns and fs TA in the visible spectral region from stilbene-localized ,* state with the double bond in the trans geometryBroad and extend to the near-IR region for 1 and 2: contribution from the acetylide ligand cationStrong RSA for the ns laser pulse at 532 nm, with complex 6 showing the strongest RSA13

Future ResearchPlatinum complexed based on cyclometallated tri-dentate ligandsIridium complexes14