关于空间群判断失误的札记Ⅱ.P空间群的修正

列举１６ 例按Ｐ１ 解出的晶体结构,其空间群应描述为单斜晶系的Ｃ２／ｃ,并讨论从Ｐ１ 修正为三方的Ｒ３ 和四方的Ｉ４１／ａ 的晶体结构各１ 例。分析揭示判断失误的线索。最后强调在结构报告中完整发表原子坐标数据的重要意义。     

关于空间群判断失误的札记Ⅱ. P(S)空间群的修正

列举16例按P(S)解出的晶体结构,其空间群应描述为单斜晶系的C2/c,并讨论从P(S)修正为三方的R(S)和四方的I41/a的晶体结构各1例.分析揭示判断失误的线索.最后强调在结构报告中完整发表原子坐标数据的重要意义.     

关于空间群判断失误的札记Ⅲ.P1空间群的修正

8个原报道属于 P 1的晶体结构应修正为对称性较高的空间群。其中 5例改变晶系和劳埃群 :4例改为 2 / m而另 1例改为 4 / m。余 3例从 P1更正为 P1,对于其中的1个结构利用原始强度数据进行了最小二乘结构再精修。     

关于空间群判断失误的札记：Ⅱ.P^—1空间群的修正

列举１６例按Ｐ＾－１解出的晶体结构,其空间群应描述为单斜晶系的Ｃ２／ｃ,并讨论从Ｐ＾－１修正为三方的Ｐ＾－３和四方的Ｉ４１／ａ的晶体结构各１例。分析揭示判断失误的线索。最后强调在结构报告中完整发表原子坐标数据的重要意义。     

关于空间判断失误的扎记Ⅳ.单斜晶系:从非心到有心空间群

报道了 12个从单斜无心修正为单斜有心的晶体结构。其中 1例从C2修正到C2 /m ,2例从P2 1 到P2 1 /c。 9例从Cc到C2 /c ,除Cc修正到C2 /c的 6例已见诸文献外 ,列出其余 6例在较高对称空间群下的原子坐标     

六方硫化钒晶体的空间群推演

晶体空间群推演是晶体结构描述和表达的关键环节,也是理论印证实验晶体结构的手段。因涉及数学方法、物理技术和图形软件,所以不仅是晶体结构教学的重点也是难点。本文基于六方硫化钒晶体结构测定的基本结构数据,用自编晶体学程序cryst 2015在图形软件上再现硫化钒的晶体结构。在点空间和三维实向量空间中,由线性映射表达平移和非平移对称操作,得到硫化钒的空间群和对应的矩阵表示群。由生成元的幂次连乘导出空间群群元素的生成顺序,以及由空间群导致的晶体学分类。这种借助实例的连贯推演方法,有助于建立晶体学知识结构框架,尤其能帮助初学者理解晶体学的科学思想体系。     

二氯-二[2-甲氧基-6-(2'-羟乙基亚胺基甲基)苯酚]合镉(Ⅱ)的结构再研究

标题化合物的晶体结构曾用单斜晶系的空间群Cc描述.我们再研究确定其空间群应为正交晶系的Fdd2.修正涉及晶体的晶系、晶类和布拉维格子类型的改变,但仍属可呈现非线性光学活性的非心对称空间群.给出了在空间群Fdd2时的非氢原子坐标和主要键长和键角值.     

关于空间群判断失误的札记I.最小素单胞的选取

导出反映晶体结构周期的最小素单胞是正确判断空间群的第一步,其中以还原单胞的选择最为理想。它不仅具有选择的唯一性,且便于确定布拉维格子的类型。本文还讨论单胞选取过小和过大的实例,并给出正确的单胞和空间群以及原子坐标。     

关于空间群判断失误的札记：Ⅰ.最小素单胞的选取

导出反映晶体结构周期的最小素单胞是正确判断空间群的第一步，其中以还原单胞的选择最为理想。它不仅上有选择的唯一性，且便于确定布拉维格子的类型。本文还讨论了单胞选取过小和过大的实例，并给出正确的单胞和空间群以及原子坐标。     

结构相角二阶代数式的应用：Ⅱ.正交空间群二阶式及其应用

以作者在前文中提出的单相角二阶代数式的推导方法为依据,在完成三斜、单斜空间群推导结果的基础上,进而又完成了正交晶系59个空间群二阶式的推导,从而提供了低级晶系(三斜、单斜和正交)全部74个空间群的简明、完备的二阶代数式运算用表。对三个晶体结构进行了相角估算,结果较好。文中提出了代数法应用的新特点,即“一种类型相角可用多种二阶式求得,多种类型相角也可用一种二阶式求算”。     

Synthese von substituierten 1, 2-Malonyl-1,2-dihydrocinnolinen (1,3-Dioxo-2, 3-dihydro-1H-pyrazolo [1, 2-a] cinnolinen) mit antiinflammatorischen Eigenschaften

A new class of antiphlogistic substances is described. They are 4-phenyl-1, 2-dihydrocinnolins diacylated in 1, 2-position by alkylmalonic acids. The compound which pharmacologically has been investigated most thoroughly is cinnopentazone (II). Its synthesis and behaviour towards hydrolytic and oxidative agents are described. Some relations between the chemical structure of these series of substances and their antiinflammatory activity as well as their classification as antiphlogistics according to some model reactions are discussed.     

Pyridylethylation of some heterocyclic thioamides and potential mercaptans

2-Pyridylethylation of benzazothiones-2 which are potential mercapto compounds (benzothiazolethione-2, benzoxazolethione-2, 1-methylbenzoimidazolethione-2, benzoimidazolethione-2, 5, 6-dimethylbenzoimidazolethione-2), is described, as well as preparation of 5, 6-dimethylbenzoimidazolethione-2 by direct oxidation of 5, 6-dimethylbenzoimidazole.     

Macromolecular effect: synthesis of a ferrocenylmethylphosphine-containing polymer as highly efficient ligands for room-temperature palladium(0)-catalyzed Suzuki cross-coupling reactions of aryl chlorides

The design and synthesis of a ferrocenylmethylphosphine-containing polymer and its application as efficient ligands for the room-temperature Pd(0)-catalyzed cross-coupling reaction of aryl chlorides with arylboronic acids, for which corresponding monomeric monophosphines are totally inactive, are described. Our work demonstrated that rather small monophosphine moieties such as RPPh2 can be used as highly efficient ligands when appropriately incorporated into a rigid and sterically regular polymer network and using monophosphine-containing polymers as ligands is a feasible approach to access highly active (monophosphine)-palladium(0) complexes. The macromolecular approach described here may open a new avenue to other coordinatively unsaturated (monoligand)-transition metal complexes which are potentially useful in organic synthesis.     

A new method for the synthesis of plurisubstituted pyrroles

A versatile method for the synthesis of pyrroles is described using an intramolecular [3+2] cycloaddition reaction. This method allows the expedient preparation of ‘plurisubstituted’ compounds in which functionality is incorporated by choice, using appropriate readily available starting materials. Polycyclic pyrrole derivatives as well as 2-aryl monocyclic analogues are described. Several families of compounds are synthesized by sequential transformations. The method is designed to allow the creation of libraries with increased diversity of functionality by combinatorial or parallel synthesis.     

Intramolecular [3+2] cycloadditions of functionalized azomethine ylides

The use of dithiane chemistry to synthesize functionalized azomethine ylides which are then employed in [3+2] cycloaddition chemistry is described. The advantages of this methodology as well as an approach to the lycorenine alkaloid system are presented.     

The motion of small numbers of ions in a Penning trap

An analysis is given of the motion of small numbers of ions (up to three) in the Penning trap. It is shown that the motion is best described in the frame rotating at half the cyclotron frequency, in which the effect of the magnetic field can be described in terms of an effective electrostatic potential. The oscillation frequencies in this frame are calculated for 1, 2 and 3 ions and related to the frequencies observed in the laboratory frame. The orientations of 2- and 3-ion crystals are calculated as a function of the trap parameters.     

Applications of quantum-classical and quantum-stochastic molecular dynamics simulations for proton transfer processes

Quantum-classical and quantum-stochastic molecular dynamics models (QCMD/QSMD) are formulated and applied to describe proton transfer processes in three model systems - the proton bound ammonia-ammonia dimer in an external electrostatic field; malonaldehyde, which undergoes a quantum tautomeric rearrangement; and phospholipase A₂, an enzyme which induces a water dissociation process in its active site followed by proton hopping to a histidine imidazole ring. The proton dynamics are described by the time-dependent Schrödinger equation. The dynamics of the classical atoms are described using classical molecular dynamics. Coupling between the quantum proton (s) and the classical atoms is accomplished via conventional or extended Hellmann-Feynman forces, as well as the time-dependence of the potential energy function in the Schrödinger equation. The interaction of the system with its environment is described by stochastic forces. Possible extensions of the models as well as future applications in molecular structure and dynamics analysis will be briefly discussed.     

Extraction of complexes of iron(III) and other metals with bis(2-ethylhexyl)phosphoric acid into molten biphenyl/naphthalene

The extraction behaviour of twelve metals as function of the concentration of nitric or hydrochloric acid is described; bis(2-ethylhexyl)phosphoric acid (BEHPA) and 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester are used as the extractants with 3:1 (w/w) biphenyl/ naphthalene (m.p. 52°C) as the molten solvent which is easily separated by cooling to room temperature. Scandium (III) and zirconium (IV) can be separated from uranium (VI), rare earth metals and some transition metals with BEHPA. The extraction behaviour of iron with both extractants is described in detail.     

Imine-enamine annelation: stereoselective syntheses of (±)-deplancheine

Two new approaches to synthesis of (±)-deplancheine (1) are described which utilize the alkylation of the imine-enamine (2) as the key ring-forming step.     

Solvent-free synthesis of heterocyclic compounds using microwaves

Microwave-enhanced solvent-free synthetic approach is described that features simplicity, manipulative ease of the operation and conservation of solvents as the main advantages. This eco-friendly approach, which has found application in facile organic functional group transformations, is applied to rapid assembly of heterocyclic compounds. A variety of solid state reactions are described that occur rapidly at ambient pressure under solventless conditions and provide ready access to intermediates such as enamines and α-tosyloxyketones which can be transformed in situ to biologically significant heterocyclic compounds such as isoflav-3-enes, flavones, quinolones, 2-aroylbenzo[b]furans and thiazoles in one-pot operation. Multicomponent reactions under these solvent-free conditions can be adapted for high speed parallel synthesis and are exemplified by assembly of dihydropyrimidine-2(1H)-ones (Biginelli reaction) and imidazo[1,2-a]annulated pyridines, pyrazines and pyrimidines (Ugi reaction) which may have potential in building a library of such compounds.