Dark-Field Oxidative Addition-Based Chemosensing: New Bis-cyclometalated Pt(II) Complexes and Phosphorescent Detection o

1. Dark-Field Oxidative Addition-Based Chemosensing: New Bis-cyclometalated Pt(II) Complexes and Phosphorescent Detection of Cyanogen Halides Samuel W. Thomas III, Koushik Venkatesan, Peter Muller, and Timothy M. Swager J. Am. Chem. Soc. 2006,128, 16641 -16648 演講者：李光凡

2. Blue-Shifting Transduction Event

3. Phosphorescence ATKINS’ Physical Chemistry 8th EDITION p 494

4. Pt(ppy) Pt(o,p-tpy) Ir(ppy)3 Ir(thpy)3 Highly Phosphorescent Bis-Cyclometalated Complexes Metal：Pt & Ir Ligand：bidentate ligand. ex : 2 - phenylpyridine Thompson, M. E. Inorg. Chem. 2002, 41, 3055-3066 Ueno, K. J. Am. Chem. Soc.2003, 125, 12971-12979

5. Homoleptic Complexes and Heteroleptic Complexes Homoleptic Complexes Heteroleptic Complexes von Zelewsky, A. Inorg. Chem. 1987, 26, 2814-2818 Stoeckli-Evans, H. Inorg. Chem. 1996, 35, 4883-4888

6. Oxidative Addition Reactions von Zelewsky, A. Inorg. Chem. 1987, 26, 2814-2818

7. Some Phosphorescent Complexes Designed for The Sensing of other Vapors Past： Now：Cyanogen halides Pilato, R. S. J. Am. Chem. Soc. 1998, 120, 12359-12360 Swager, T. M. J. Am. Chem. Soc. 2003, 125, 3420-3421

8. Stille coupling 1d：4-methyl – 68% 1e：5-methyl – 29% 1f：6-methyl – 96% Synthesis of thpy Ligands 1b：R=CH3 – 97% 1c：R=OCH3 – 93% Suzuki coupling 2a：R=H – 62% 2b：R=CH3 – 51%

9. Synthesis of Bis-Cyclometalated Pt(II) Complexes 3

10. Synthesis of Bis-Cyclometalated Pt(II) Complexes 4 Steric congestion

11. Synthesis of Bis-Cyclometalated Pt(II) Complexes 5 1a：thienylpyridine

12. Photophysical Parameters of Pt(II) Complexes 3-5

13. Ligand-centered absorption MLCT Normalized UV/vis Spectra of Complexes 3a-d in THF 3a in THF ： 423 nm 3a in acetone ：419 nm (blue-shift) 3a in toluene ：430 nm (red-shift) 3b and 3c electron density↑ (red-shift)

14. Normalized UV/vis Spectra of Complexes 3e, 3f, 4a, and 5 in THF 3f & 4a：broadened MLCT absorbance band.

15. Room-Temperature Emission Spectra of Phosphorescent Bis-Cyclometalated Pt(II) Complexes in THF Quantum yields of emission between 0.05 and 0.30

16. X-ray Crystal Structures of 3b (left) and 3f (right) Severely distort 46.4° Pt1 – N1 = 2.169 Å Pt1 – N2 = 2.165 Å Pt1 – C7 = 1.985 Å Pt1 – C17 = 1.982 Å Pt1 – N1 = 2.139 Å Pt1 – N2 = 2.179 Å Pt1 – C3 = 1.98 Å Pt1 – C13 = 1.974 Å Slightly distort 16.4°

17. UV/vis Spectra of 3b During Its Reaction with 1.0 M MeI in Benzene

18. Pseudo-First-Order Rate Plot for 3b in 1.0M MeI/Benzene

19. UV/vis, for 3a, with Either MeI or BrCN (in Benzene)

20. MLCT disappearance UV/vis Spectra of 3b React with 0.00013 M BrCN in Benzene

21. First-Order Kinetic Plot for The Reaction of 3b with BrCN

22. Percentage Conversion of 3a In Either Toluene or Benzene

23. Conversion Percentages of Several Pt(II) Complexes

24. Bimolecular Rate Constants of Platinum Complexes with MeI in Benzene

25. What Is PMMA? 1.聚甲基丙烯酸甲酯，又稱做壓克力或有機玻璃。 2.可見光：PMMA是目前最優良的高分子透明材料，透光率達到92％，比玻璃的透光度高。 3.紫外光：石英能完全透過紫外線，但價格高昂，普通玻璃只能透過0.6％的紫外線，但PMMA卻能透過73％。 http://zh.wikipedia.org/w/index.php?title=%E9%A6%96%E9%A1%B5&variant=zh-tw

26. Normalized Emission Spectra of 3a In degassed THF Solution and Doped into PMMA Films

27. PMMA/Pt(II) Spun-Cast Films of 4a (Top) and 3a (Bottom) under UV Light + BrCN + BrCN

28. PMMA Film Emission Spectra of 3a (a) and 4a (b) before (Dotted) and after (Solid) Exposure to BrCN Vapor for 15 s 3a 4a

29. Conclusions • A new dark-field turn-on optical chemosensing scheme has been developed using bis-cyclometalated platinum complexes. A series of these complexes was synthesized, most of which have not been previously reported in the literature. • Thin polymer films containing these complexes, which were phosphorescent at room temperature, also reacted with cyanogen halide vapors to give the blue-shifted Pt(IV) products.

30. HOMEWORK 1.BrCN接到此錯合物的構型是cis或是trans ? Ans:由此文章中得知，當結構扭曲越嚴重時BrCN接上的速度越快，代表不可能是trans的構型因此是屬於cis的結構，因此由構造可以再次證明BrCN是屬於SN2的反應。且由本文中的圖1可推出構造可能是cis。

31. HOMEWORK 2.Homoleptic和Heteroleptic有哪些不同之處? Ans:由table 1知道Homoleptic complex 3a的量子產率比Heteroleptic complex 5的量子產率明顯高很多，代表Homoleptic complex的放光強度比Heteroleptic complex高出許多。而Heteroleptic complex 5和BrCN反應的速率比Homoleptic complex 3a和BrCN反應的速率快，作者在此篇文章說原因不明，個人猜測是因為3a上的S會拉電子導致BrCN接上的速度比較慢。