Properties of a genetic algorithm extended by a random self-learning operator and asymmetric mutations: A convergence study for a task of powder-pattern indexing

Genetic algorithms represent a powerful global-optimisation tool applicable in solving tasks of high complexity in science, technology, medicine, communication, etc. The usual genetic-algorithm calculation scheme is extended here by introduction of a quadratic self-learning operator, which performs a partial local search for randomly selected representatives of the population. This operator is aimed as a minor deterministic contribution to the (stochastic) genetic search. The population representing the trial solutions is split into two equal subpopulations allowed to exhibit different mutation rates (so called asymmetric mutation). The convergence is studied in detail exploiting a crystallographic-test example of indexing of powder diffraction data of orthorhombic lithium copper oxide, varying such parameters as mutation rates and the learning rate. It is shown through the averaged (over the subpopulation) fitness behaviour, how the genetic diversity in the population depends on the mutation rate of the given subpopulation. Conditions and algorithm parameter values favourable for convergence in the framework of proposed approach are discussed using the results for the mentioned example. Further data are studied with a somewhat modified algorithm using periodically varying mutation rates and a problem-specific operator. The chance of finding the global optimum and the convergence speed are observed to be strongly influenced by the effective mutation level and on the self-learning level. The optimal values of these two parameters are about 6 and 5%, respectively. The periodic changes of mutation rate are found to improve the explorative abilities of the algorithm. The results of the study confirm that the applied methodology leads to improvement of the classical genetic algorithm and, therefore, it is expected to be helpful in constructing of algorithms permitting to solve similar tasks of higher complexity.     

Solvothermal Synthesis and Structure Characterization of a 3D Hydrogen-bonded Copper Compound [Cu(H_2dhpmc)_2]·2H_2O

1 INTRODUCTION The controlled assembly of inorganic and coordination polymers from simple building blocks is an important challenge in the design of high- dimensionality systems. In the crystal engineering 'toolbox'[1], hydrogen bonding moieties are perhaps the implements used the most in the design of such supramolecular systems[2], and have been particularly strongly applied towards the synthesis of molecular magnetic materials[3~6]. Copper complexes play an important role in catalyzin…     

Synthesis, structure, and spectroscopy of phenylacetylenylene rods incorporating meso-substituted dipyrrin ligands

The synthesis, structure, and spectroscopic characterization of a series of phenylacetylenylene rodlike molecules containing dipyrromethene (dipyrrin) ligands are described. The combination of the phenylacetylenylene groups with the porphyrinogenic dipyrrin moieties results in a rich absorption spectroscopy for these compounds, although the fluorescence of the phenylacetylenylene moiety is quenched by presence of the dipyrrin chelator. The Cu(2+) and Fe(3+) complexes of these ligands have been prepared and three of these compounds have been structurally characterized by using single-crystal X-ray diffraction. Unlike other octahedral metal-dipyrrin complexes described to date, one of the iron complexes demonstrates ideal threefold symmetry in the solid-state. The elongated structure and high symmetry of these complexes suggests the use of these meso-substituted phenylacetylenylene ligands as an interesting class of extended, branched molecules for the construction of supramolecular architectures.     

水相中金属铜表面生成亚铜—邻菲罗啉配合物的反应

本文研究了零价铜在邻菲罗啉水溶液中的反应。当溶液敞露于空气并存在有机阴离子Ｘ－时，例如苯甲酸盐（Ｂｚ）、对甲基苯磺酸盐（Ｔｓ）等，铜的表面生成了致密的反应产物的薄层，经ＩＲ、ＵＶ／ＶＩＳ、ＭＳ和元素分析证明了该薄层为相当纯的亚铜的邻菲罗啉配位化合物，结构为［Ｃｕ（ｐｈｅｎ）２］＋Ｘ－。在乙醇／甲苯混合溶剂中得到了表面反应产物的晶体［Ｃｕ（ｐｈｅｎ）２］（ＣＨ３Ｃ４Ｈ６ＳＯ３）Ｃ２Ｈ５ＯＨ，并用Ｘ－ｒａｙ测得了结构。本工作表明溶液中的ＣｕⅡ离子抑制Ｃｕ０氧化成ＣｕⅠ而影响反应层的形成，同时又促进ＣｕⅠ氧化成ＣｕⅡ的过程     

Spectrophotometric determination of copper after adsorption of its 1-phenyl-4,4,6-trimethyl(1H, 4H)-pyrimidine-2-thiol complex onto microcrystalline naphthalene

A selective Spectrophotometric method has been developed for the trace determination of copper after adsorption of its 1-phenyl-4,4,6-trimethyl(1H, 4H)-pyrimidine-2-thiol (PTPT) complex onto microcrystalline naphthalene. The complex is quantitatively adsorbed on naphthalene in the pH range 7.5–11.5, separated by filtration, dissolved in dimethylformamide (DMF) and determined spectrophotometrically at 400 nm. Beer's law is obeyed in the concentration range 2.5–37.5 g of copper in 10 ml of DMF. The molar absorptivity and Sandell's sensitivity are 1.30 × 10⁴1 · mol^–1 · cm^–1 and 0.0048g cm^–2, respectively. Ten replicate analyses of a solution containing 20.0 g of copper gave a mean absorbance of 0.410 with a relative standard deviation of 0.91 %. The interferences of various ions have been studied and the method has been validated by the determination of copper in various standard reference materials, beers, wines, human hair, goat liver and environmental samples.On leave from St. Stephen's College, Delhi 110 007, India     

比值光谱导数法同时测定铝合金中铁,铜,锌

用比值光谱－导数分光光度法，在ｐＨ５．５缓冲溶液中，利用金属－２－（５－溴－２－吡啶偶氮）－５－二乙氨基酚（５－Ｂｒ－ＰＡＤＡＰ）－ＯＰ三元络合物显色体系，对混合物中铁，铜，锌三组分进行了同时测定。合成试样５次测定回收率在９７．３％－１０４．４％之间。应用于铝合金中铁，铜，锌的测定，各６次测定的ＲＳＤ分别为３．６６％，１．３８％，２．０３％。     

Mass spectrometric study of thermal stability of copper(II) bis(dipivaloylmethanate) vapour

The processes of thermal destruction of copper(II) bis(dipivaloylmethanate) (Cu(dpm)₂) in the temperature range 150°–550°C were studied by using a two-temperature variant of a double chamber Knudsen cell, with mass spectrometric recording of the gas-phase composition. The temperature range of stability of the vapour of the complex in vacuum was determined, as were those of its mixtures with oxygen in different proportions. The temperature dependence of the rate constant of the thermolysis of (Cu(dpm)₂) vapour was obtained. The thermal stability of Hdpm vapour and the influence of oxygen on the thermolysis of the ligand were studied.

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Zusammenfassung Unter Verwendung einer Zweitemperaturenvariante der Knudsenschen Doppelkammerzelle wurde mittels MS-Untersuchung der Gasphasenzusammensetzung im Temperaturbereich 150°–550°C der thermische Abbau von Kupfer(II)-bis(dipivaloylmethanat) (Cu(dpm)₂) untersucht. Es wurde der Temperaturbereich für die Stabilität der gasförmigen Komplexe in Vakuum sowie in Gemischen mit Sauerstoff in verschiedenen Verhältnissen bestimmt. Dabei wurde die Temperaturabhängigkeit der Geschwindigkeitskonstante für die Thermolyse von Cu(dpm)₂ ermittelt. Weiterhin wurde die thermische Stabilität von Hdpm-Dampf sowie der Einfluß von Sauerstoff auf die Thermolyse der Liganden bestimmt.

     

Preparation and crystal structure of hydrated crystalline complex of ciprofloxacin and copper tetrachloride

Synthesis of a complex formed by ciprofloxacin (cfH) and copper(II) chloride is described; its crystal structure is reported and analyzed in comparison to related compounds. The obtained compound (cfH₃)CuCl₄·H₂O (cfH ₃ ²⁺ — double protonated cfH molecule) crystallizes as platelets of P2₁/c symmetry having the unit cell parameters a = 13.491(1) Å, b = 11.0459(7) Å, c = 16.299(1) Å; β = 111.392(7)°. Carbonyl oxygen O(1) is protonated, and hydrogen atom combined with it forms an intramolecular hydrogen bond with carboxylic O(2) oxygen (O(1)?O(2) = 2.642(5) Å). Terminal nitrogen atom N(3) of the piperazinyl group is also protonated, and two its hydrogen atoms participate in hydrogen bonds of N-H?Cl type. The structure also has hydrogen bonds O-H?O, O-H?Cl with the participation of water molecules which occupy hydrophilic channels. Molecular ions cfH ₃ ²⁺ make couples with intrapair π?π interactions.     

Silica-supported Copper（Ⅱ） Catalyzed Coupling of Arylboronic Acids with Imidazoles

Immobilized copper（Ⅱ） in organic-inorganic hybrid materials catalyzed Ar-N coupling of arylboronic acids with imidazoles has been developed. Arylboronic acids reacted with imidazoles smoothly in the presence of a 3-（2-aminoethylamino）propyl functionalized silica gel immobilized copper（Ⅱ） catalyst （10 mol%） in methanol without any additives and bases. The reactions generated the corresponding cross-coupling products in good yields. Furthermore, silica-supported copper can be recovered and recycled by a simple filtration procedure and used for five consecutive trials without decreases in activity.     

[Cu(H2O)(phen)2](CIO4)2的晶体结构

标题化合物晶体属三斜晶系;空间群为P₁;晶胞参数:a=8.182(2)Å,b=10.389(2)Å,c=16.261(5)Å,α=99.38(2)°,β=89.97(2)°,γ=113.18(2)°;Z=2,两个phen上的四个N原子和一个配位水中的O原子围绕中心体Cu原子形成一个畸变的三角双锥构型,配位水与阴离子ClO₄^-中的O原子形成氢键。