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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.
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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
Phosphorescence ATKINS’ Physical Chemistry 8th EDITION p 494
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
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
Oxidative Addition Reactions von Zelewsky, A. Inorg. Chem. 1987, 26, 2814-2818
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
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%
Synthesis of Bis-Cyclometalated Pt(II) Complexes 4 Steric congestion
Synthesis of Bis-Cyclometalated Pt(II) Complexes 5 1a：thienylpyridine
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)
Normalized UV/vis Spectra of Complexes 3e, 3f, 4a, and 5 in THF 3f & 4a：broadened MLCT absorbance band.
Room-Temperature Emission Spectra of Phosphorescent Bis-Cyclometalated Pt(II) Complexes in THF Quantum yields of emission between 0.05 and 0.30
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°
UV/vis Spectra of 3b During Its Reaction with 1.0 M MeI in Benzene
MLCT disappearance UV/vis Spectra of 3b React with 0.00013 M BrCN in Benzene
Bimolecular Rate Constants of Platinum Complexes with MeI in Benzene
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
Normalized Emission Spectra of 3a In degassed THF Solution and Doped into PMMA Films
PMMA/Pt(II) Spun-Cast Films of 4a (Top) and 3a (Bottom) under UV Light + BrCN + BrCN
PMMA Film Emission Spectra of 3a (a) and 4a (b) before (Dotted) and after (Solid) Exposure to BrCN Vapor for 15 s 3a 4a
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.
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。
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。
