Experimental and Theoretical Study for Dimer-of-Dimers-type Tetrarhodium(II) Complexes Bridged by 1,4-Benzenedicarboxylate Linkers
Experimental and Theoretical Study for Dimer-of-Dimers-type Tetrarhodium(II) Complexes Bridged by 1,4-Benzenedicarboxylate Linkers
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1,4-苯二甲酸酯连接体桥接的二聚体型四铑(II)配合物的实验和理论研究
DOI：
10.1039/c8dt03293a
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发表时间：
2018
影响因子：
4
通讯作者：
Makoto Handa
中科院分区：
文献类型：
--
作者：
Yusuke Kataoka;Kazuki Arakawa;Hikaru Ueda;Natsumi Yano;Tatsuya Kawamoto;Makoto Handa
合成了两种二聚体-二聚体型四钠配合物[Rh4(piv)6(BDC)] （[1]; piv = pivalate）和[Rh4(piv)6(F4BDC)]([2])，其中两个轮状二钠单元分别由1,4-苯二甲酸酯（BDC）和1,4-四氟苯二甲酸酯（F4BDC）连接，并通过单晶x射线衍射分析、ESI-MS、1H NMR、红外光谱、拉曼光谱和元素分析对其进行了表征。对分别由[1]和[2]的THF溶液结晶而成的[1(THF)4]和[2(THF)4]的晶体结构分析表明，[1(THF)4]中两个-CO2单元和BDC连接剂苯环之间的二面角（φ）几乎是共面的（φ = 2.8°），而[2(THF)4]中F4BDC连接剂的二面角（φ = 78.3°）很大程度上是倾斜的。密度函数理论计算表明：(1)[1(THF)4]和[2(THF)4]的优化几何形状的二面角与实验几何形状基本一致；(2)势能表面分析估计[1(THF)4]和[2(THF)4]中苯基基团的旋转能垒分别为12.0和8.4 kcal mol−1，表明[1(THF)4]中BDC连接剂苯基环的两个-CO2单元和四个氢原子之间形成了氢键。而[2(THF)4]中F4BDC连接剂苯基环上的两个-CO2单元和四个氟基团是静电和空间排斥的。[1(THF)4]和[2(THF)4]的电化学性能和电子结构受二羧酸酯连接物的电子态的强烈影响，而吸收光谱受二羧酸酯连接物的两个-CO2单元和苯环之间的二面角的强烈影响。
Two dimer-of-dimers-type tetrarhodium complexes, [Rh4(piv)6(BDC)] ([1]; piv = pivalate) and [Rh4(piv)6(F4BDC)] ([2]), in which two paddlewheel-type dirhodium units are linked by 1,4-benzenedicarboxylate (BDC) and 1,4-tetrafluorobenzenedicarboxylate (F4BDC), respectively, have been synthesized and characterized via single-crystal X-ray diffraction analyses, ESI-MS, 1H NMR, infrared spectroscopy, Raman spectroscopy, and elemental analyses. Crystal structure analyses of [1(THF)4] and [2(THF)4], which are crystallized from THF solutions of [1] and [2], respectively, revealed that dihedral angles (ϕ) between two –CO2 units and phenyl rings of the BDC linker in [1(THF)4] are almost co-planar (ϕ = 2.8°), whereas those of the F4BDC linker in [2(THF)4] are largely inclined (ϕ = 78.3°). Density functional theory calculations clarified that (i) their dihedral angles of optimized geometries of [1(THF)4] and [2(THF)4] are almost the same as their experimental geometries, and (ii) the rotation energy barriers of phenyl moieties in [1(THF)4] and [2(THF)4] estimated by potential energy surface analyses are 12.0 and 8.4 kcal mol−1, respectively, indicating that hydrogen bondings are formed between two –CO2 units and four hydrogen atoms of phenyl rings of the BDC linker in [1(THF)4], whereas two –CO2 units and four fluorine groups on the phenyl ring of the F4BDC linker in [2(THF)4] are electrostatically and sterically repulsed. Electrochemical properties and electronic structures of [1(THF)4] and [2(THF)4] are strongly influenced by the electronic states of dicarboxylate linkers, whereas absorption spectra are strongly influenced by the dihedral angles between two –CO2 units and phenyl rings of dicarboxylate linkers.