Indium-mediated Facile Synthesis of （6-Chloropyridine-3-yl）methyl Heterocyclic Thioether Derivatives in Aqueous Media

A series of substituted (6-chloropyridine-3-yl)methyl heterocyclic thioether derivatives were prepared by indium mediating in water. The preliminary biological tests showed that compound 3d exhibited good antiviral activity.     

Fused multifunctionalized bridge aromatic hydrocarbons from in situ-generated arynes and anthracene derivatives

This study presents a facile strategy for the formation of highly substituted butterfly 1,4-adducts/9,10-adducts via the Diels–Alder reaction of benzyne intermediates. The method achieves very good to excellent yields of the respective anthracene derivatives under mild conditions. This practical protocol is compatible with a variety of sensitive functional groups and provides access to difunctionalized bridge 1,4-adducts/9,10-adducts.     

Magnetic properties of dendritic polycarbenes substituted by bulky peripheral groups

As photo-reactive precursors of high-spin organic compounds sterically separated from surroundings by bulky peripheral groups, diphenyldiazomethane derivatives substituted by tetrakis{3,5-bis(benzyloxy)benzyloxy} groups 1, by tetrakis[3,5-bis{3′,5′-bis(benzyloxy)benzyloxy}bezyloxy] groups 2, and nonakisdiazo compound associated with ferromagnetic spin couplers substituted by dodecakis{3,5-bis(benzyloxy)benzyloxy} groups 3, were prepared and their magnetic properties after irradiation in their own condensed films were investigated. Field dependences of magnetization and temperature dependences of χT value after irradiation of 1 and 2 clearly exhibited that spin centers i.e., diphenylcarbene parts of 1 and 2 were magnetically isolated from surrounding molecules each other by steric hindrance of the peripheral bulk substituents even in the neat films. In the case of 3, some part of molecules interacted antiferromagnetically with neighboring molecules but a fatal strong antiferromagnetic interaction was also avoided.     

1，4二环己基取代六元瓜环与Na(Ⅰ)自组装实体的合成与晶体结构

A novel complex of a new 1,4-dicyclohexyl cucurbituril(DCYQ[6]) with sodium(Ⅰ) ion was synthesized, and the crystal structure was determined by X-ray diffraction technique. In this self-assembled entity both the cavity interaction of DCYQ[6] included a nitrate anion and the portal interaction of the dipole carbonyls of DCYQ[6] with sodium cations lead to form self assembled molecular capsules. The crystal structure of the entity shows a packing of the self assembled molecular capsules connected by hydrogen bonds of water molecules. CCDC: 271400.     

新型螺环六氢山酮素-氧化吲哚-苯并呋喃酮类拼接物的合成及其抗白血病细胞增殖活性

以色酮-氧化吲哚合成子与3-烯基苯并呋喃酮为原料,在催化剂1,8-二氮杂二环十一碳-7-烯作用下,在二氯甲烷中发生Michael/Michael加成关环反应,合成了6个未见文献报道的螺环六氢山酮素-氧化吲哚-苯并呋喃酮类拼接物(3a^3f),产率75%~87%,dr值3/1~5/1,其结构经1H NMR,13C NMR和HR-MS(ESI-TOF)表征。采用MTT法研究了3a^3f对人白血病细胞(K562)的体外抗增殖活性。结果表明:化合物3c,3e和3f对K562增殖有一定的抑制活性。     

Is [Cu3(L2)Cl2]2+ a molecule with geometrically spin frustration? DFT study on magnetic competing interaction in hetero-bridged tricopper(II) complex

The theoretical calculations on magnetic exchange interaction of the hetero-bridged tricopper(II) complex [Cu₃(L²)Cl₂]²⁺ and a related binuclear copper(II) model are carried out by using the density functional theory combined with the broken-symmetry approach. Meanwhile, one strategy computationally, so called isolated magnetic pair approach, is suggested to explore the spin frustration from geometry topology in poly-nuclear magnetic systems. It is found that the ferromagnetic coupling (J₂>0) of Cu1–Cu3 pair bridged by double μ–Cl ligands, in nature, is intrinsic, not resulted from geometrically spin frustration in the hetero-bridged tricopper(II) studied. However, in the whole molecule exist two competing contributions of antiferromagnetic and ferromagnetic coupling, and the antiferromagnetic coupling (J₁) from Cu1–(μ–OR)–Cu2 and Cu2–(μ–OR)–Cu3 pairs dominates the magnetic behavior of the whole molecular system. On the other hand, the variation of J₁/J₂ ratio affects significantly on magnetic properties of the system. The calculated effective magnetic moment μ_eff of 2.26μ_B at the OPerdew functional level is compared to experimentally observation of 2.70μ_B in the solution. The briefly analysis of molecular magnetic orbitals demonstrated that the two local magnetic orbitals on Cu1 and Cu3 ions are orthogonal each other, and primarily responsible for the intrinsic ferromagnetic coupling between Cu1–(μ–Cl)₂–Cu3. By comparison of spin population distributions for the Cu-triad and Cu-dimer the validity of the isolated magnetic pair approach is confirmed.     

Recent advances on deoximation: From stoichiometric reaction to catalytic reaction

Recent advances on the deoximation reactions are reviewed in this review. It was shown that catalytic deoximation with molecular oxygen as the mild oxidant should be the developing trend of the reaction.     

The λφ4 coupling at high temperature

Some erroneous claims about λφ⁴ scalar field theory are corrected. In particular, the coupling λ(T) is shown to grow logarithmically with temperature for large T.     

一类具有变号位势Kirchhoff型方程解的存在性

该文研究了一类带有变号位势非线性项的Kirchhoff型方程的Neumann边值问题.利用变分方法,首先对空间进行分解,证明了该问题的能量泛函满足山路结构;然后证明了能量泛函的(PS)序列有强收敛的子列;最后通过Ekeland变分原理和山路引理,获得了该问题两个非平凡解的存在性.     

Growth instability in diffusion controlled polymerization

We report the observation of a sharp transition in the structure of polypyrrole prepared via diffusion controlled polymerization in a quasi-two dimensional electrochemical cell. As the oxidation potential is increased, the fractal dimension drops sharply from values near 2 (compact structures) to 1 as the growth becomes dendritic. At higher potentials, where the polymerization becomes diffusion limited, a continuum of structures is observed as the dendrites become irregular and the fractal dimension increases to 1.74+-0.01. The mean branch angle was also measured and found to decrease from 90° at the point of dendritic growth, to 45° at high potential.