Laser spectroscopic studies of several Rydberg states of MgO

We report extensive spectroscopic measurements of rovibronic transitions from the MgO X 1Sigma+ ground state to the high-energy E 1Sigma+, F 1Pi1, and G 1Pi1 Rydberg states. Perturbations in the E 1Sigma+ and G 1Pi1 states were observed. The Rydberg molecular orbital character of the three states is examined, given ab initio calculations by Thummel et al. [Chem. Phys. 129, 417 (1989)]. It is concluded that the E 1Sigma+ and G 1Pi1 states consist primarily of the MgO+ X 2Pi ionic core, surrounded by 3ppi and 3psigma Rydberg electron clouds, respectively, and that the F 1Pi1 state consists primarily of the MgO+ A 2Sigma+ ionic core surrounded by a 3ppi Rydberg electron cloud. Spectroscopic characterizations of some unassigned vibrational levels of analogous MgO 3Pi2 states in this energy region are also reported.     

单质碘促进的有机反应研究进展

单质碘作为有机化学中结构最为简单的反应试剂之一,其促进的有机转化在最近几年越来越受到人们的关注.总结了单质碘的氧化性,酸性和亲电性3类基本化学性质,并针对3类性质所涉及的相关反应性报道进行了介绍.除此之外,还总结了近5年来单质碘作为催化剂在杂环合成,偶联反应,及C—H官能团转化等方面的应用.     

Au/γ-MnO2催化剂催化无溶剂条件下甲苯氧化反应

采用氧化还原法制备了α, δ, γ-MnO₂载体, 采用原位还原法制备了Au负载量为0.5%-3.0%的Au/γ-MnO₂催化剂, 并采用X射线衍射、扫描电镜、透射电镜和N₂物理吸附等手段对其进行了表征. 透射电镜照片表明Au/γ-MnO₂催化剂中Au颗粒的大小约为10 nm. 采用无溶剂存在下的甲苯氧化反应测试所制备样品的催化活性. 结果表明, 甲苯转化率随着Au负载量的增加而增大. 这是由于Au颗粒数量增多, 尺寸减小的缘故. 同时, 负载Au颗粒对苯甲醛具有较高的选择性. Au/γ-MnO₂催化剂具有良好的重复使用性.     

Hydrogen Bond and π–π Interactions in a 3D Supramolecular Structure Containing 1D Helical Chains

The reaction of 2, 2′‐bipyridine‐6, 6′‐dicarboxylic acid (H₂bpdc) with zinc nitrate and different rare earth chlorides generates two novel three‐dimensional supramolecules Zn(6‐bpc)₂ · 2H₂O ( 1 ) and Ce(bpdc)₂ · H₂O ( 2 ) (6‐Hbpc = 2, 2′‐bipyridine‐6‐carboxylic acid). The left‐and right‐handed helical chains give rise to a 3D supramolecular framework through hydrogen‐bond and weak π–π interactions in complex 1 . Interestingly, the decarboxylation occurred and the bpdc ligand was transformed into 6‐bpc species under the hydrothermal reaction in the presence of Nd^III ions, while the decarboxylation did not occur when Ce^III ions were used. In the structure of 2 , one central Ce(IV) atom coordinates to two bpdc ligands, resulting in a discrete molecule. These discrete units are further extended into a 3D supramolecular structure through intermolecular hydrogen bonds and π–π interactions.     

酸性离子液体[Hnmp]HSO4催化下一锅三组分反应合成N-(2-羟基-1-萘基)(苯基)甲基-吡咯烷-2-酮衍生物

在无溶剂条件下,利用廉价无毒的酸性离子液体[Hnmp]HSO4为催化剂,醛、2-萘酚和吡咯烷酮一锅三组分合成了一系列新颖的N-(2-羟基-1-萘基)(苯基)甲基-吡咯烷-2-酮衍生物.与现有的方法相比该方法避免使用有机溶剂,且反应时间短,产率高,离子液体廉价易制备,且可回收重复再利用.     

Highly efficient synthesis of a class of novel chiral-bridged atropisomeric monophosphine ligands via simple desymmetrization and their applications in asymmetric Suzuki-Miyaura coupling reaction

A series of novel chiral-bridged atropisomeric monophosphine ligands were synthesized via convenient and simple pathways. The prepared ligands, especially for ligand 7d, were found to be highly effective in the Pd-catalyzed Suzuki-Miyaura coupling reaction. The steric hindrance and electronic effect of substrates on the reactivity and enantioselectivity were explored preliminarily.