Synthesis and Crystal Structure of (L)_2W(CO)_4·CH_3COCH_3 (L=1-Phenacylimidazole)

1 INTRODUCTION Due to their variability in binding modes, five- membered heterocyclic ligands such as pyrazole[1] and 1,2,4-triazole[2] have been drawn much attention. Consequently, there are numerous reports on their derivatives. Imidazoles resemble pyrazoles, and they are isomeric five-membered heterocyclic molecules containing two nitrogen atoms. Furthermore, imida- zole is also a ring component of adenine and purine, one of the most versatile binding sites in biological systems, so th…     

Deposition features of Ni on self-assembled microtubule template from biolipid by electroless method

The self-assembly of lipid molecules is in close relationship with the structure and function of a cell membrane. A cell membrane has a variety of lipid molecules. Lipid molecules have their amphiphile na-tures, and their self-assembly can form a variety of thermodynamically stable microstructures, such as single-bilayer or multi-bilayer spherical and ellipsoidal liposome, microcylindrical and microtubular struc-tures[1]. These microstructures exhibit different bio-logical functions in living …     

Multicomponent Reaction in Ionic Liquid： A Novel and Green Synthesis of 1, 4-Dihydropyridine Derivatives

1, 4-Dihydropyridine (DHP) heterocyclic ring is a common feature of various bioactivecompounds such as vasodilator, bronchodilator and antiatherosclerotic, antitumor, andantidiabetic agents1. Due to their important pharmacological activities, many methods…     

Synthesis and Crystal Structure of Cis 2-（6-Chloro-3-pyridylmethylamino）-4-chlorophenyl- 5,5-dimethyl- 1,3,2-dioxaphosphinane 2-Oxides

1 INTRODUCTION Neonicotinioid insecticides as nicotinic acetyl-choline receptor inhibitors have attracted increasingattention because of its safety, low toxicity, wide andhigh activities[1, . A lot of new insecticides such as 2]imidacloprid, acetamiprd and nitenpyram have beencommercialized. It is found that most biologicallyactive nicotinic compounds contain 3-aminomethyl-pyridine moiety[3]. Due to their wide biological acti-vities, organic phosphorus heterocyclic compoundsplay an import…     

Thermal Behavior and Decomposition Kinetics of the Complexes of CuX_2 (X=NO_3, Br, Cl and ClO_4) with 3,3''''-Dimethyl-1-(1H-1,2,4-triazol-1-yl)-2-butanone

Introduction N-1-Alkyl-substituted 1,2,4-triazole compounds, like some other heterocyclic derivatives containing nitrogen, have recently been the subjects of numerous studies due to their fungicidal action1 and plant growth regulation.2 Among them, the complexes with a sort of triazole as ligand are of considerable interest because of their broad-spectrum bioactivity, coordination and photo-chemical properties, as well as many potential applica-tions in various fields.3,4 In our previous paper…     

Fabrication of Ni-decorated helical ribbon composite microstructure from self-assembled lipid tubule by electroless metallization

Molecular self-assembly is a powerful approach for preparing new supermolecular architectures such as nanofibers and nanotubes[1]. Lipid molecules, due to their amphiphilic nature, can self-assemble to form a variety of microstructures, such as spherical liposome, tubules and helical ribbons[2]. Many lipid molecules can self-organize into the helical ribbon structures[3,4], for example, helical ribbons were self-assembled in a variety of multicomponent enantiomerically pure sys- tems that cont…     

Synthesis, Crystal Structure and Electrochemical Properties of the Complex Cd（α-FRA）2（Phen）（H2O）

1 INTRODUCTION The syntheses and structures of carboxyl complex- es have captured the interest of chemists for years due to their potential applications in many fields, such as materials, medicine, molecular electro-che- mistry and biochemistry[1～3]. So far, to the best of our knowledge, cadmium complexes with aromatic carboxylic acid as ligands have been intensively studied[4～7], but those with heterocyclic carboxylic acid as ligands are much less. α-Furoic acid is widely used in orga…     

Localized molecular orbital studies of certain compounds with [A_3X_3] six-membered rings

The localized molecular orbitals (LMOs) of certain quasi-aromatic organic and inor-ganic molecules with six-membered rings have been calculated by virtue of the ab initio methodusing STO-3G and 4-31G basis sets as well as the CNDO/2 method. It is shown that there existsextensively-delocalized p-pπ bonding in these quasi-aromatic systems. The localized pictures ofthe π-type LMOs for the heterocyclic and homocyclic systems from the σ-π localization schemeare discussed. The Generator Orbital approach is utilized to account for the bonding patterns.     

Synthesis and Crystal Structure of 3-Phenyi- 6-（4-methylphenyi）-1,2,4-triazolo[4,3-b]-1,2,4-triazine

1 INTRODUCTION The fused heterocycles bearing 1,2,4-triazine have attracted considerable attention in recent years owing to their biological and pharmaceutical activi- ties[1～3]. The 1,2,4-triazine core is a versatile synthe- tic platform to access a wide range of condensed heterocyclic ring systems via inter- and intramolecu- lar Diels-Alder reaction with a vast array of dieno- philes[4～6]. IBD (iodobenzene diacetate) is commer- cially available and used as benign non-metallic oxidant…     

Synthesis and application on parallel image storage of bisfurylfulgide

The synthesis of photochromic compounds has received a great deal of attention because of their potential application in various areas such as optical information storage[1—5], photoswitches and molecular recognition[6—8]. One of the most important researches in this field is the synthesis of a variety of photochromic fulgides to establish basic correlation between their molecular structures and photochromic properties. Since 1978, Heller[9] firstly reported the synthesis of the heterocyclic…     

THE MASS SPECTRA OF HKTEROCYCLIC CONJUGATED COMPOUND AND ITS QUANTUM CHEMICAL CALCULATIONS

A mechanism of cleft-rate-determining-step of furfurol,furylacrylic acid,dimethylfuran,thiophene-2-aldehyde,and pyrrole-2-aldehyde is.proposed,and various quantum parameters of molecular ions of these compounds and their fragments are calculated by using CNDO/2 method.The peak-height of mass spectra is quantitatively interpreted.This method could be extended to heterocyclic conjugated compounds.     

稳定剂KI对化学镀Ni-Fe-P-B合金性能的影响

Influences of stabilizer (KI) on the corrosion performance of the Ni-Fe-P-B deposit alloys,were investigated using electrochemical methods,weightless corrosion and heat treatment.The results show that corrosion current density (0.1585mA·cm~(-2)),porosity(0.5 No.cm~(-2)) and weightless corrosion rate of the deposit (Ni-Fe-P-B) in corrosion media are lowest,when the stabilizer (KI) concentration is 8mg.L~(-1).Corrosion resistance of the deposit drops to a different degree in the range of 200℃～600℃,and slowly falls down when CKI=8mg.L~(-1).The lattice changes and diffusion layer forming of the deposit play important roles in the changes of corrosion performance in the different range of heat treatment.However,the hardness and abradability of testing alloy increase to a different degree in 200～400℃.When CKI=8mg.L~(-1),hardness of alloy is as high as 950HV after heat treatment at 400℃×1h,which is twice that of the as-plated coating.     

A New Strategy for Architecture of Robust Monolayer Based on Binuclear Palladium (II) Complex of Calix[4]arene Derivative

Since calixarenes and their derivatives have unique coordination abilities to metal ions and inclusion abilities toward neutral organic molecules, they have been widely studied in the field of molecular recognition, transportation and separation1. In order to explore these functions, membranes such as monolayers and Langmuir-Blodgett (LB) films formed by calixarenes, are often used for these purposes2-6. However, a crucial factor that hinders their application is the weak mechanical strength …     

Syntheses and Crystal Structures of Benzyltin（Ⅳ） Derivatives of 2-Mercaptobenzothiazole

Introduction Metal thiolato complexes have been extensively investigated because of their ability to adopt various nuclearities and their relevance in biological science, since they form the inorganic part of the biologically active centers of some metalloproteins and enzymes.1-3 Recently, attention has been paid to the coordination chemistry of heterocyclic thiol/thione donors, which can give potential access to new compounds with unusual structures and reactivities,4 such as 2-mercaptobenzo-…     

Statistical theory for hydrogen bonding fluid system of A_aD_d type(Ⅲ):Equation of state and fluctuations

The equation of the state of the hydrogen bonding fluid system of AaDd type is studied by the principle of statistical mechanics. The influences of hydrogen bonds on the equation of state of the system are obtained based on the change in volume due to hydrogen bonds. Moreover,the number density fluc-tuations of both molecules and hydrogen bonds as well as their spatial correlation property are inves-tigated. Furthermore,an equation describing relation between the number density correlation function of "molecules-hydrogen bonds" and that of molecules and hydrogen bonds is derived. As application,taking the van der Waals hydrogen bonding fluid as an example,we considered the effect of hydrogen bonds on its relevant statistical properties.     

Theoretical Studies on Intermolecular Interactions of 4-Amino-5-nitro-1,2,3-triazole Dimers

1 INTRODUCTION Triazole, a five-membered heterocyclic compound with three nitrogen atoms, is an important interme- diate product of medicine and chemical industry as well as insecticide [1]. Due to its small volume and high nitrogenous density, triazole holds more and more attraction for the material researchers, espe- cially the researchers of high-energy insensitive explosive. It is reported that its nitro and amino deri- vatives are a sort of important high-energy mate- rials[2]. Previ…     

Synthesis, Crystal Structure and Antibacterial Activity of 1-（（2-Chloroquinolin-3-yl）-methyl）-pyridin-2（1H）-one

On the basis of the interesting structures and biological activities exhibited by several heterocyclic systems possessing the pyridone nucleus such as mappcine and camptothecin, we have planed to design the synthesis, crystal studies and antibacterial activity of the new 1-((2- chloroquinolin-3yl)-methyl)-pyridine-2(1H)-one building block. An X-ray analysis has provided valuable insight into the effect of steric factors on the three-dimensional shape of this compound which serves as a useful advanced intermediate in the synthesis of these biologically active molecules. A multistep synthesis of camptothecin (5) has been designed by retrosynthetic analysis as part of an ongoing program on lead anticancer drug.     

Crystal Structure of Chlorinate （N,N-1,3-Dibenzyl-benzimidazole） Hydrate

1 INTRODUCTION Benzimidazole is an interesting heterocyclic ring because it is present in various naturally occurring drugs, such as omeprazole, astemizole and emedastine difumarate[1]. The efficacy of substituted benzimidazoles in the treatment of parasitic infections is well known[2～4], and the pharmacophores in parasitic chemotherapy are established by benzimidazole-substituted moieties. Bis(2-benzimidazoles) and some substituted bis- (benzimi-dazol-2-yl) alkanes have attracted much…     

STUDIES OF THE ANTENNA EFFECT IN POLYMER MOLECULES ENERGY MIGRATION AND TRAPPING IN NAPHTHALENE-CONTAINING POLYELECTROLYTES*

Polymers of 1- and 2-vinylnaphthalene containing more than about 50mol% sulfonic acid groups dissolve in water to form "hypercoiled" conformations whichhave many of the properties of micelles. Hydrophobic molecules such as anthracene andperylene are selectively absorbed in these pseudo micellar structures, and their fluorescenceemission is sensitized by energy transfer from the surrounding naphthalene chromophores.When irradiated with UV light in the presence of oxygen, the emission of perylene rapidlydecreases. It is proposed that this is due to reaction of singlet oxygen with the perylenetrapped in the hypercoiled polymer.     

Isolation and Characterization of an Antimicrobial Polypeptide from Loach

Hydrobionts formed their special defense systems during evolution. One such system is that of non-specific immunity which comprises a wide variety of peptides with potent antimicrobial activities1. The mechanism of action of most antimicrobial peptides was reported as that a few peptide molecules formed a channel on cell membrane, and the cell was then died of the outflowing of cellular contents. The above mechanism was different from that of antibiotics2, 3. It is a promising area to disc…