Problems in Chemistry

利用数学方法解决化学问题是化学及相关专业学生必备的技能之一。作者Daley,H.O.针对这一需要,为大学学习普通化学的学生编写了这本习题集。通过解题学生可以检验自己对化学原理掌握的深浅程度。     

“Reviews in Macromolecular Chemistry”

Abstract

In the homopolymerization and copolymerization of vinyl acetate with dibutyl maleate in the presence of the sodium salt of sulfosuccinic acid semiester with nonylphenol ethoxylated with 25 mol ethylene oxide, the initiator, potassium persulfate (KPS), has a higher decomposition rate than in water even after consumption of monomer. The value of the initiator productivity, P, defined as the ratio of the formed polymer over the decomposed KPS, decreases as the batch stage of the semicontinuous process proceeds. The initiator reacts either with free surfactant molecules or with those grafted on poly(vinyl acetate) chains. During the stage of continuous addition of monomers and KPS, a smaller initiator concentration no longer provides proportionality between the added and decomposed amounts of initiator. The increased monomer concentration at the beginning of continuous addition causes the rate of KPS splitting to decrease as most of the surfactant is bound to the surface monomer/polymer particles.     

Rearrangements in Spiro-λ4-sulfane Chemistry

The reactions of possible spiro-λ⁴-sulfane precursor diaryl sulfoxides with dehydrating agents have been studied resulting in the formation of cyclic anhydride, spiro-λ⁴-sulfane, cyclic sulfonium-ylide, lactam-sulfoxide, cyclic sulfonimide and cyclic sulfilimine type of intermediates or products. The structures of the intermediates or products depend on the functional groups attached to the aryl rings at ortho positions and on the reaction conditions applied.     

Science in China Series B： Chemistry

Science in China Sero B： Chemistry, a peer-reviewed academic journal, covers the novel and important research results in the basic and applied fields of chemistry, providing a forum for high-level academic communication.     

“Trends in Polymer Chemistry 1995”简介

“ＴｒｅｎｄｓｉｎＰｏｌｙｍｅｒＣｈｅｍｉｓｔｒｙ１９９５”简介［编者按］ＡｃｔａＰｏｌｙｍｅｒｉｃａ自１９９４年起，每年发表一篇有关上一年度高分子化学论文的综述，该综述对无暇涉猎浩繁文献的读者，简捷地了解新动向颇有帮助。此文发表在１９９６年第４期。...     

Progress in Chemistry Cumulative Index(2002)

Inorganic ChemistrySynthesis of Silica Molecular Sieves and Their U se in Fine Chemicals 14 ( 1) ,0 0 1The Research Progress of Ni-containing Enzymes and Model Compounds 14 ( 1) ,0 47Metalβ-Diketonates Used as Precursors for Ferroelectric Oxide Thin Films 14 ( 1) ,0 6 1Progress in the Recognition and Repair of DNA Dam age 14 ( 4 ) ,2 39Studies on Transmembrane Transportation of Rare Earths by Fluorescence and Patch-Clamp Methods 14 ( 4 ) ,2 46Application of Patch-Clamp Techniq…     

Progress in Chemistry Cumulative Index(2001)

Inorganic ChemistryNanostructure and Analysis of Porous Carbons 13 (1) ,10Development of Titanium Silicon Catalytic Materials I.Preparation of Titania-Silica Mixed Oxides and Its Catalytic Properties 13 (1) ,19Catalysis of Multi-Nitrogen Chelated L ate-Transition-Metal Complexes for Olefin Polymerization 13 (2 ) ,10 2Current Developm ent in the Heterogenization of Homogeneous Catalysis—— Fluorous Biphase System 13 (3 ) ,192Research Progress of Supercritical Carbon Dioxide Flu…     

Hot Topics in Polysaccharide Chemistry – Selected Examples

Summary: The paper highlights recent developments in polysaccharide chemistry. Cellulose tert-butyl- and thexyldimethylsilyl ethers with degree of substitution up to 2 were accessible and comprehensively characterized by means of NMR spectroscopy. These derivatives enable the preparation of 3-O-functionalized cellulose ethers. Especially the allyl ether as protecting group at position 3 can be used for the synthesis of 2,6-di-O-methyl cellulose. Nucleophilic displacement reactions of cellulose p-toluenesulfonic acid esters with amines afforded deoxyamino celluloses that form stable monolayers on different substrates. Based on 6-deoxy-6-azido cellulose, dendrons with a focal alkyne moiety were bound via the copper(I) catalyzed Huisgen reaction. Moreover, dextran derivatives were synthesized that form stable nanoparticles useful, e.g., for the determination of the pH value in biological systems.     

Conference “Russian Scientific Schools in Chemistry”

Information Congresses, Conferences, Symposia, Meetings, and Seminars in the Field of Chemical Sciences Held with the Participation of the Russian Academy of Sciences

Conference Russian Scientific Schools in Chemistry     

The First-Year Chemistry Laboratory in the United States

本文是张树永教授为《大学化学》杂志向Kelter教授特约的专稿,主要介绍美国大学一年级实行分层次化学教学的一些作法,以及大学一年级化学课程教学体系和实验教学体系、教学内容和教学方法。虽然美国大学化学实验课程的内容不像我国那样多,但涉及面广,更强调学生的自主学习和自我训练,同时将仪器分析作为实验的必要内容嵌入日常实验当中,使实验内容的综合性、设计性更强,也更贴近日常生活和科学实验。这些作法对我国的大学化学实验教学改革具有借鉴作用。     

Hexa-Coordinate phosphorus Chemistry and Life Chemistry

The amino acids' side chains were acting as the relay device to regulate the chemical reactivi-ties of the N-phosphoryl amino acids. These modulation effects were performed through the partici-pation of the phosphoryl group.     

Nitrene Chemistry in Organic Synthesis: Still in Its Infancy?

The element nitrogen is essential to life. Considerable attention is thus paid to the development of synthetic methods for its introduction into molecules. Nitrenes, long regarded as highly reactive but poorly selective species, have recently emerged as useful tools for the formation of C-N bonds. Practical metal-catalyzed protocols are now available for the preparation of amines through either the aziridination of alkenes or the C-H amination of alkanes. Recent results highlighted in this Minireview suggest that synthetic nitrene chemistry is maturing with a wider scope not limited to these two reactions.     

Report On ‘Chemistry in a Biological Context’

The American Chemical Society has started its first large-scale project related to opening up new options for undergraduate majors. Tentatively titled Chemistry in a Biological Context, the work has only just begun. Participants are invited to provide early feedback into the nature and shape of the project.