过硫化氢分子及过硫化氢离子低电子态的理论研究

为了丰富过硫化氢分子和过硫化氢一价阳离子的电子基态和激发态的信息,采用量子化学中密度泛函理论的B3LYP方法,使用6-311++g(3df,3pd)基组,对其进行了研究。计算得到了过硫化氢分子HSSH基态和过硫化氢离子HSSH+基态及激发态的平衡构型、光谱常数、总能量和零点振动能。计算表明:过硫化氢中性分子是长对称陀螺分子,二面角为90.66°,具有C_2对称性,而过硫化氢离子HSSH+有顺式(二面角为0°)和反式(二面角为180°)两种稳定的异构体,反式结构基态能量比顺式结构基态能量低0.129 e V;此外计算还得到了过硫化氢离子HSSH+两种异构体的基态和激发态的电子结构。

电子与H_2O和H_2S分子散射总截面的计算

利用光学势方法计算了能量在10eV～1000eV范围内电子被氮原子、氧原子和硫原子散射的总截面.并利用可加性规则得到了电子被水分子和硫化氢分子散射的总截面。计算结果与已有的实验数据进行了比较.在200eV～1000eV的能量范围内计算结果和实验数据符合得比较好。

Molecular Simulation Study on Intrinsic Order of Interaction between Single Slab of Active Phase and Al-Si Support in HDS Catalysts

Molecular mechanics and quantum mechanics simulations, as molecular simulation methods, were performed to investigate the effects of different surfaces, the promoter Co/Ni, the active phase of MoS2 or WS2, the content of Si and other factors on the order of interaction between the MoS2 （WS2） single slab and the support surface. The influence of Si content was studied by molecular mechanics, and an advantageous Si content was found. Various surfaces, promoters and active phases also played an important role in the interaction between the support surfaces and active phases, and some significant trends were found out. Quantum mechanics simulation was performed to study the possible effect of electrostatic interaction between the support and the active phase, upon which the calculations suggested that the existence of a favorable Si content was possible. The electronic effects of Co/Ni promoter and the intensity of Co/Mo/Ni/W/Li/AI/Si species bonded to the alumina support were also investigated by quantum mechanics, and it was found that the different electronic effects of Co and Ni might bring forth some obvious influences on the interaction between the support and the active phase. And the results of comparing the intensity of Co/Mo/Ni/W/Li/AI/Si species bonded to the support can also explain the different interaction intensity in various catalyst systems.

H_2S分子的振转光谱和势能面的理论研究

报道了用已观测到的36个振动谱带的带心实验值优化的H2S分子的有效势能面. 利用该势能面, 采用振动自洽场组态相互作用VSCF-CI方法计算出H2S的高激发振转态的能量, 其值与观测之标准偏差为0.091 cm-1. 在此基础上, 使用两步变分法研究了局域模效应, 并计算出一些目前尚未观测到的弱吸收谱带的带心. 其中局域模振动态的能级分裂值与观测结果一致, 如(300)态分裂的观测值为0.163 cm-1, 计算值是0.159 cm-1; 而由KJ势能面得到的能级分裂值是-0.03 cm-1.

Organic nanoparticles formed by aggregation-induced fluorescent molecules for detection of hydrogen sulfide in living cells

Hydrogen sulfide(H_2S)has been found to be the third most important endogenous gaseous signaling molecule after nitric oxide(NO)and carbonic oxide(CO)and plays crucial roles in living organisms and biological systems.Here we use aggregation-induced emission(AIE)of a small organic molecule(TPE-indo)to detect H_2S in both solution and living cells.TPE-indo can target mitochondria and aggregate to fluoresce,which can serve as a sensor for monitoring H_2S in the mitochondria.We regulate the fluorescence of AIE molecules by tuning the viscosity of the solution to form TPE-indo nanoparticles,constructing a probe for H_2S with good selectivity and high sensitivity.The nucleophilic addition of HS-to the TPE-indo is crucial for the rapid H_2S detection.The imaging and analysis of H_2S in mitochondria of living cells with the probe demonstrate potential biological applications.

Triggering a [2]rotaxane molecular shuttle through hydrogen sulfide

A novel chemically-controlled [2]rotaxane molecular shuttle was successfully designed and synthesized. A H_2 S-responsive bulk barrier was introduced between the two identical recognition stations of the [2]rotaxane to prevent dynamic shuttling of the macrocycle. Upon addition of H_2 S, the complete intramolecular cascade reaction occurs in a controllable manner, resulting in removal of the bulk barrier and the shuttling motion of the macrocycle between the two stations recovers.