Electronic and spectroscopic properties of avobenzone derivatives attached to ditungsten quadruple bonds.
Electronic and spectroscopic properties of avobenzone derivatives attached to ditungsten quadruple bonds.
复制标题
连接到二钨四键的阿伏苯宗衍生物的电子和光谱特性。
DOI：
10.1021/acs.inorgchem.5b01221
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发表时间：
2015
影响因子：
4.6
通讯作者：
Young,PhilipJ
中科院分区：
文献类型：
--
作者：
Chisholm,MalcolmH;Gustafson,TerryL;Kender,WilliamT;Spilker,ThomasF;Young,PhilipJ
From the reactions between W2(TiPB)4, where TiPB is 2,4,6-triisopropylbenzoate, and 2 equiv of acid, 4-formylbenzoic acid, HBzald, 4-(3-oxo-3-phenylpropanoyl)benzoic acid, HAvo, or 4-(2,2-difluoro-6-phenyl-2H-1λ3,3,2λ4-dioxaborinin-4-yl)benzoic acid, HAvoBF2, three new compounds W2(TiPB)2(Bzald)2,I, W2(TiPB)2(Avo)2,II, and W2(TiPB)2(AvoBF2)2,III, have been prepared. As solid compoundsIandIIare blue while compoundIIIis green. Characterization of these compounds has been carried out by means of1H NMR, MALDI-TOF MS, steady-state absorption and emission spectroscopies, and femtosecond and nanosecond transient absorption and time-resolved infrared spectroscopies. CompoundsIandIIhave strong metal to ligand charge transfer, MLCT, transitions in the visible region of their spectra while compoundIIIexhibits MLCT absorption in the near-infrared (λmax= 1017 nm). All three have S1states that have corresponding lifetimes of ∼3–30 ps and are1MLCT in character. The triplet states are3MLCT with lifetimes in the range 3–10 ns. Density functional theory and time-dependent density functional theory were employed to perform electronic structure calculations in order to aid in the interpretation of these data. The spectroscopic properties ofIandIIare similar while the planarity of the ligand inIIIgreatly lowers the energy of the MLCT state. The W2unit enables direct observation of intersystem crossing from the1MLCT state to3MLCT state via the use of ultrafast spectroscopy.
