Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210-1185, USA.
Dalton Trans. 2013 Oct 28;42(40):14491-7. doi: 10.1039/c3dt51684a.
From the reactions between the quadruply bonded complexes M2(T(i)PB)4, where M = Mo or W and T(i)PB = 2,4,6-triisopropylbenzoate, and the carboxylic acids HOOC-C6H4-4-B(mesityl)2, LH (2 equivalents) the complexes trans-M2(T(i)PB)2L2 have been prepared. The new compounds have been characterized by (1)H NMR, MALDI-TOF MS, UV-Vis-NIR and steady-state emission spectroscopy, time-resolved transient absorption spectroscopy and cyclic voltammetry. These results are compared with the related properties of the benzoates, M2(T(i)PB)2(O2CPh)2 (prepared similarly) and with DFT calculations on model compounds where formate substitutes for T(i)PB. The new compounds M2(T(i)PB)2L2 are intensely colored in toluene or THF solutions: red (M = Mo) and green (M = W) and the introduction of the p-B(mesityl)2 group notably shifts these metal to ligand charge transfer transitions to lower energy in comparison to the benzoate complexes M2(T(i)PB)2(O2C-C6H5)2. Upon the addition of fluoride ions these intense absorptions are shifted to much higher energy in a reversible manner for M = Mo.
从四重键复合物 M2(T(i)PB)4 与羧酸 HOOC-C6H4-4-B(mesityl)2 的反应中，LH（2 当量）制备了复合物 trans-M2(T(i)PB)2L2。新化合物通过（1）H NMR、MALDI-TOF MS、UV-Vis-NIR 和稳态发射光谱、时间分辨瞬态吸收光谱和循环伏安法进行了表征。这些结果与相关苯甲酸酯的性质进行了比较，即 M2(T(i)PB)2(O2CPh)2（以类似的方式制备），并对模型化合物进行了 DFT 计算，其中甲酸盐取代了 T(i)PB。新化合物 M2(T(i)PB)2L2 在甲苯或 THF 溶液中呈现强烈的颜色：红色（M = Mo）和绿色（M = W），并且与苯甲酸酯复合物 M2(T(i)PB)2(O2C-C6H5)2 相比，p-B(mesityl)2 基团的引入显著将这些金属到配体电荷转移跃迁移到更低的能量。对于 M = Mo，当加入氟离子时，这些强烈的吸收以可逆的方式被转移到更高的能量。
