Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, Mail Code 0358, La Jolla, San Diego, 92093-0358, USA.
Dalton Trans. 2010 Dec 7;39(45):10937-43. doi: 10.1039/c0dt00780c. Epub 2010 Oct 18.
The new mononuclear and dinuclear tricarbonylrhenium(I) complexes [(HATN)Re(CO)(3)Cl] (1-Cl) and [(μ-Me(6)-HATN)Re(CO)(3)Cl] (2-Cl(2)) of highly symmetric ligands HATN and Me(6)-HATN were synthesized and structurally characterized. X-Ray crystal structures reveal identical strained aromatic systems and out of the plane fac-Re(CO)(3)Cl units for both complexes. The packing geometry in the unit cell of 1 suggests intermolecular π-π association. Infrared spectroelectrochemistry (SEC) experiments confirmed ligand-based reductions. To get more insight into the reduction mechanism the triflate salts, (HATN)Re(CO)(3) (1-OTf) and (μ-Me(6)HATN){Re(CO)(3)}(2)(2) (2-OTf(2)), were synthesized. Their electrochemical and spectroelectrochemical behavior also exhibits reduction of the aromatic systems. The electronic absorption spectral features of the one electron reduced species were studied by UV-vis-NIR spectroscopy, which shows a broad shoulder at 1500 nm, confirming intra-ligand charge transfer (ILCT). Density functional theory (DFT) calculations on the complexes 1-Cl and 2-Cl(2) for structural optimization show good agreement with experimental bond lengths and bond angles. The spin density plot shows a metal based HOMO and HATN ligand centered LUMO.
高对称配体 HATN 和 Me6-HATN 的单核和双核三羰基铼(I)配合物(HATN)Re(CO)3Cl和(μ-Me6-HATN)Re(CO)3Cl被合成并进行了结构表征。X 射线晶体结构揭示了两个配合物具有相同的应变芳香体系和非平面 fac-Re(CO)3Cl 单元。1 中单元的堆积几何形状表明存在分子间π-π 缔合。红外光谱电化学（SEC）实验证实了配体还原。为了更深入地了解还原机制，合成了三氟甲磺酸盐(HATN)Re(CO)3(1-OTf)和(μ-Me6-HATN){Re(CO)3}(2)2(2-OTf(2))。它们的电化学和光谱电化学行为也显示出芳香体系的还原。通过紫外可见近红外光谱研究了单电子还原物种的电子吸收光谱特征，该光谱在 1500nm 处显示出一个宽肩，证实了内配体电荷转移（ILCT）。对配合物 1-Cl 和 2-Cl(2)进行结构优化的密度泛函理论（DFT）计算与实验键长和键角吻合良好。自旋密度图显示了基于金属的 HOMO 和以 HATN 配体为中心的 LUMO。
