Brown-Xu Samantha E, Chisholm Malcolm H, Durr Christopher B, Spilker Thomas F, Young Philip J
The Ohio State University, Department of Chemistry and Biochemistry, 100 W. 18 Avenue, Columbus, Ohio, 43202, USA.
Chem Sci. 2015 Mar 1;6(3):1780-1791. doi: 10.1039/C4SC02542C. Epub 2015 Jan 13.
From the reactions between M(T PB) compounds and and - vinylbenzoic acids (2 equiv) in toluene at room temperature the compounds -M(T PB)L, where L = -vinylbenzoate (M = Mo) and (M = W) and T PB = 2,4,6-triisopropylbenzoate, and where L = -vinylbenzoate (M = Mo) and (M = W) have been isolated. Compounds and have been shown to undergo Heck carbon-carbon coupling reactions with phenyliodide to produce -Mo(T PB)(OCCH--CH=CH-CH) and -Mo(T PB)(OCCH--CH=CH-CH), . The molybdenum compounds and have been structurally characterized by single crystal X-ray crystallography. All the new compounds have been characterized by H NMR, IR, UV-Visible absorption and emission spectroscopy, high resolution MALDITOF MS, fs- and ns- transient absorption spectroscopy and fs- time-resolved IR spectroscopy. Electronic structure calculations employing density functional theory, DFT, and time-dependent DFT have been employed to aid in the interpretation of spectral data. All compounds show intense absorptions in the visible region corresponding to Mδ to Lπ* charge transfer transitions. The lifetimes of the MLCT state fall in the range of 1 - 10 ps and for the molybdenum complexes the T states are δδ* with lifetimes ~50 μs while for the tungsten complexes the T are MLCT with lifetimes in the range of 3 - 10 ns.
在室温下，M(TₚB)化合物与2当量的α-乙烯基苯甲酸在甲苯中反应，分离得到了化合物-M(TₚB)L，其中L = α-乙烯基苯甲酸酯（M = Mo）和（M = W），TₚB = 2,4,6-三异丙基苯甲酸酯，以及L = β-乙烯基苯甲酸酯（M = Mo）和（M = W）。已表明化合物 和 与苯碘发生Heck碳-碳偶联反应，生成-Mo(TₚB)(OCCH₂CH=CH-CH₃)和-Mo(TₚB)(OCCH₂CH=CH-CH₃)， 。钼化合物 和 已通过单晶X射线晶体学进行了结构表征。所有新化合物均通过¹H NMR、IR、UV-可见吸收和发射光谱、高分辨率MALDI-TOF MS、飞秒和纳秒瞬态吸收光谱以及飞秒时间分辨红外光谱进行了表征。采用密度泛函理论（DFT）和含时DFT的电子结构计算有助于对光谱数据进行解释。所有化合物在可见光区域均表现出强烈吸收，对应于Mδ到Lπ电荷转移跃迁。MLCT态的寿命在1 - 10 ps范围内，对于钼配合物，T态为δδ，寿命约为50 μs，而对于钨配合物，T态为MLCT，寿命在3 - 10 ns范围内。
