二硫杂[3.3]对环番单金属钌炔基配合物的合成及性质

Synthesis and properties of dithia[3.3] paracyclophane-based monometallic ruthenium acetylide complexes

设计合成了3个含不同取代基的二硫杂[3.3]对环番单金属钌炔基化合物6b^6d及一个对照化合物6a.4个化合物通过1H NMR,13C NMR,31P NMR和元素分析进行了表征.化合物6c的结构通过X射线单晶衍射证实,晶体结构显示环芳中上下苯环间存在明显的?–?作用.同时还利用电化学、红外光谱以及密度泛函理论计算,探究了二硫杂[3.3]对环番配体及其上取代基对金属钌中心电子性质的影响.电化学研究结果显示,二硫杂[3.3]对环番上取代基(F,CN)可以通过分子内的跨环?–?作用影响钌中心的氧化还原活性,其中氰基的影响最大.密度泛函理论计算结果显示取代基(F,CN)对配合物的最低未占分子轨道(LUMO)电子云密度分布影响较大,氰基取代的6c和氟取代的6d,其LUMO轨道上的电子几乎定域在桥配体的环番上,而6a和6b,其LUMO轨道上的电子几乎定域在金属钌及其辅配体上.

A series of dithia[3.3] paracyclophane-based monometallic ruthenium acetylide complexes 6b-6d and a referential complex 6a have been synthesized. All of the complexes have been characterized by NMR spectrometry and elemental analyses. X-ray crystal structure study revealed that there was intramolecular π-π interaction in complex 6c. A combination of electrochemical, spectroscopic （UV-vis, IR） and density functional theory （DFT） calculations has been employed to probe the influence of the nature and substituents of the dithia[3.3] paracyclophane bridge on the properties of metal ruthenium center. Electrochemistry studies indicated that the substituted groups （F, CN） on the dithia[3.3]-paracyclophane ring clearly affected the oxidation activities of the ruthenium center by way of the intramolecular π-π interaction, and the effect of cyano group is the most significant. The results of the DFT calculations demonstrated that the substituents （F, CN） had marked effect on the electron density distribution of the LUMO orbitals in the complexes, in which the electron almost localized on the cyclophane of bridge ligands for the cyano substituted complex 6c and fluorinated 6d, while the ruthenium center and auxiliary ligands almost completely held all the electron for the complexes 6a and 6b.