Photoinduced hydrogen abstraction‐coupling reaction mechanism of Δ5‐steroids with substituted 1, 4‐benzoquinones via electron transfer pathways

The photochemical reaction between three A⁵‐steroids (1–3) and a series of substituted 1,4‐benzoquinones and their mechanistic study were reported. The reaction in nitrogen atmosphere led to the formation of three products including the steroid‐quinone coupling compound (A), 7‐hydroxy derivatives of Δ⁵‐steroids (B) and substituted 1, 4‐hydroquinone (C). Both chemical and spectrometric evidences such as UV‐Visible spectra, ESR, chemically induced dynamic nuclear polarization (CIDNP) and cyclic voltammetry (CV) verified that the title reaction underwent a predominant photoinduced electron transfer pathway via the triplet quinone.     

Synthesis of 2-Substituted Hexahydro-1H-1,4-diazepine Analogues

Opioids have attracted increasing research interest, primarily because of their powerful pain relieving properties and their potential for recreational abuse1,2. In order to get some selectiveκ-opioid receptor agonists, which can elicit analgesia while lacking serious side effects, a series of hexahydro-1H-1,4-diazepine analogues carrying the segment of (1-arylacetamide-2-tertiaryamine) ethane have been synthesized in our laboratory. The κ-opioid receptor antagonistic activity3of these compo…     

二苯基锗二硫代氨基甲酸酯的合成及表征

合成了10种二苯基锗二硫代氨基甲酸酯Ph2Ge(S2CNR2)2,用元素分析、IR、^1H NMR和MS表征了这些化合物的结构,体外实验表明,这些化合物对MCF－7,WiDr和EC癌细胞具有较的抑制活性。     

串级非线性及其应用

文章介绍了串级非线性概念,讨论了串级过程及其物理思想,并指出了它的可能应用。     

Energy Level Statistics of SO（5） Limit of Super-symmetry U（6/4） in Interacting Boson-Fermion Model

We study the energy level statistics of the SO（5） limit of super-symmetry U（6/4） in odd-A nucleus using the interacting boson-fermion model. The nearest neighbor spacing distribution （NSD） and the spectral rigidity （Δ3） are investigated, and the factors that affect the properties of level statistics are also discussed. The results show that the boson number N is a dominant factor. If N is small, both the interaction strengths of subgroups SO^B（5） and SO^BF （5） and the spin play important roles in the energy level statistics, however, along with the increase of N, the statistics distribution would tend to be in Poisson form.     

端羟基聚环氧环己烷的合成

端羟基聚环氧环己烷的合成;端羟基聚环氧环己烷;环氧环己烷;阳离子聚合     

Nevanlinna theory through the Brownian motion

In this paper, we introduce the Nevanlinna theory using stochastic calculus, following the works of Davis(1975), Carne(1986) and Atsuji(1995, 2005, 2008 and 2017), etc. In particular, we give(another) proofs of the classical result of Nevanlinna for meromorphic functions and the result of Cartan-Ahlfors for holomorphic curves by using the probabilistic method.     

Space‐Confined Atomic Clusters Catalyze Superassembly of Silicon Nanodots within Carbon Frameworks for Use in Lithium‐Ion Batteries

Incorporating nanoscale Si into a carbon matrix with high dispersity is desirable for the preparation of lithium‐ion batteries (LIBs) but remains challenging. A space‐confined catalytic strategy is proposed for direct superassembly of Si nanodots within a carbon (Si NDs?C) framework by copyrolysis of triphenyltin hydride (TPT) and diphenylsilane (DPS), where Sn atomic clusters created from TPT pyrolysis serve as the catalyst for DPS pyrolysis and Si catalytic growth. The use of Sn atomic cluster catalysts alters the reaction pathway to avoid SiC generation and enable formation of Si NDs with reduced dimensions. A typical Si NDs?C framework demonstrates a remarkable comprehensive performance comparable to other Si‐based high‐performance half LIBs, and higher energy densities compared to commercial full LIBs, as a consequence of the high dispersity of Si NDs with low lithiation stress. Supported by mechanic simulations, this study paves the way for construction of Si/C composites suitable for applications in future energy technologies.     

Alkyl substituents triggered an unexpected formation of mono-and dinuclear zirconium hydrazonate complexes: synthesis,characterization and their catalytic behavior toward ethylene polymerization

Mononuclear zirconium complex 3a of the molecular identity [Zr[η²-(C₄H₃O)C (Et) = NNPh]Cl₃(THF)₂], dinuclear zirconium complexes 3b [{Zr[η²-(C₄H₃O)C(i-Pr) = NNPh]₂}₂(μ²-Cl)₃(μ³-Cl)₂Li(Et₂O)] and 3c [{Zr[η²-(C₄H₃O)C(t-Bu) = NNPh]₂}₂Cl₂(μ²-Cl)₂] have been synthesized by the treatment of lithium salt of (C₄H₃O)C(R) = NNHPh (R = CH₃CH₂, 1a ; R = (CH₃)₂CH, 1b ; R = (CH₃)₃C, 1c ), with different molar ratios of anhydrous zirconium tetrachloride. Of these, complex 3b was formed with lithium adduct and no such adduct was found in complex 3c . Compound 1a and all the zirconium complexes ( 3a - 3c ) were structurally characterized by single-crystal X-ray diffraction studies. Thus, it revealed that each hydrazonato ligand acts in a strained η²-coordination fashion for the three zirconium complexes. The molecular structures of the three zirconium complexes ( 3a - 3c ) reveal the existence of intramolecular hydrogen bonding interactions. Interestingly, complexes 3a and 3b assemble into a two-dimensional network structure through intermolecular hydrogen-bonding interactions. Upon activation with methylaluminoxane (MAO), all the complexes namely 3a , 3b , and 3c exhibited moderate catalytic activities toward ethylene polymerization and produced high molecular weight polyethylene with narrow molecular weight distributions.     

Synthesis and characterization of highly soluble wholly aromatic polyamides containing both furanyl and phenyl units

This paper presents the synthesis and characterization of two series of polymeric compounds comprising eight furan-based polyamides prepared via melt polycondensation at low temperatures using various combinations of five aromatic raw materials. The chemical and physical structures and thermal stabilities of the obtained polyamides were investigated by various characterization methods. In addition, the polyamides were subjected to solubility testing in five common organic solvents. The results showed that the proposed furan-based polyamides possessed thermal stabilities similar to those of conventional high-performance aromatic polyamides, but with greatly improved solubility. Accordingly, the introduction of furan groups increased the solubility of the polyamides with respect to the solubility of their individual precursors, which is highly advantageous for subsequent polyamide processing and expanding their range of potential applications.