Dipyridinoarsole: a new class of stable and modifiable heteroatom-bridged bipyridines

2020 ◽  
Vol 56 (45) ◽  
pp. 6035-6038 ◽  
Author(s):  
Toshiki Fujii ◽  
Susumu Tanaka ◽  
Shotaro Hayashi ◽  
Hiroaki Imoto ◽  
Kensuke Naka
Keyword(s):  
Chemical Structure ◽  
Absorption And Emission ◽  
New Class ◽  
Electrochemical Reversibility

Dipyridinoarsole, having high air-stability and electrochemical reversibility, has been experimentally and computationally studied. The chemical structure was selectively modified to tune the absorption and emission wavelengths and to realize electrochromism.

scholarly journals A theorized new class of polyhedral hydrocarbons of molecular formula CnHn and their bottom-up scaffold expansions into hyperstructures

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Camila M. B. Machado ◽  
Nathalia B. D. Lima ◽  
Sóstenes L. S. Lins ◽  
Alfredo M. Simas
Keyword(s):  
General Formula ◽  
Chemical Structure ◽  
Molecular Formula ◽  
Fusion Reactions ◽  
3D Scaffold ◽  
3D Scaffolds ◽  
Bottom Up ◽  
New Class ◽  
Euler’S Theorem ◽  
2D And 3D

AbstractWe address the use of Euler's theorem and topological algorithms to design 18 polyhedral hydrocarbons of general formula CnHn that exist up to 28 vertexes containing four- and six-membered rings only; compounds we call “nuggets”. Subsequently, we evaluated their energies to verify the likelihood of their chemical existence. Among these compounds, 13 are novel systems, of which 3 exhibit chirality. Further, the ability of all nuggets to perform fusion reactions either through their square faces, or through their hexagonal faces was evaluated. Indeed, they are potentially able to form bottom-up derived molecular hyperstructures with great potential for several applications. By considering these fusion abilities, the growth of the nuggets into 1D, 2D, and 3D-scaffolds was studied. The results indicate that nugget24a (C24H24) is predicted to be capable of carrying out fusion reactions. From nugget24a, we then designed 1D, 2D, and 3D-scaffolds that are predicted to be formed by favorable fusion reactions. Finally, a 3D-scaffold generated from nugget24a exhibited potential to be employed as a voxel with a chemical structure remarkably similar to that of MOF ZIF-8. And, such a voxel, could in principle be employed to generate any 3D sculpture with nugget24a as its level of finest granularity.

A new class of dimeric product isolated from the fungus Chaetomium globosum: evaluation of chemical structure and biological activity

2020 ◽  
Vol 73 (5) ◽  
pp. 320-323
Author(s):  
Christopher Sarmales-Murga ◽  
Fumito Akaoka ◽  
Michio Sato ◽  
Jun Takanishi ◽  
Takashi Mino ◽  
...  
Keyword(s):  
Biological Activity ◽  
Chemical Structure ◽  
Chaetomium Globosum ◽  
New Class ◽  
Dimeric Product

N-Alkyl Pyrrolidones for Plasticizing Polyurethane Elastomers

2015 ◽  
Vol 812 ◽  
pp. 9-13
Author(s):  
András Bánhegyi ◽  
José Trujillo Vilaboy ◽  
Kálmán Marossy
Keyword(s):  
Strong Interaction ◽  
Chemical Structure ◽  
Alkyl Chain ◽  
Polyurethane Elastomers ◽  
Dynamic Mechanical ◽  
New Class ◽  
Trade Names ◽  
Long Alkyl Chain

Polyurethane (PU) products produced from the reaction of isocyanates and polyols have one of the most extensive consumption of plastics. After the invention in 1937 PU had to wait until the 50’s to spread worldwide and since then their development have been continuous. In PU systems are used varied additives, including plasticizers, which are use by several large companies.In our work a new class of plasticizers, namely N-alkyl-pyrrolidones were used in polyurethane systems. Their trade names are Flexidone® 100, Flexidone® 300 and Flexidone® 500 containing 8, 12 and 18 C-atom long alkyl chain, respectively. These plasticizers showed excellent results in our previous works and the literature has also confirmed their great properties. We supposed that this chemical structure can form a strong interaction with the urethane group.The effect was monitored by hardness and dynamic mechanical (DMA) measurements. Migration and thermally stimulated discharge (TSD) measurments are in progress.

A New Class of Antitumortrans-Amine-Amidine-Pt(II) Cationic Complexes: Influence of Chemical Structure and Solvent on in Vitro and in Vivo Tumor Cell Proliferation

2010 ◽  
Vol 53 (16) ◽  
pp. 6210-6227 ◽  
Author(s):  
Cristina Marzano ◽  
Silvia Mazzega Sbovata ◽  
Valentina Gandin ◽  
Davide Colavito ◽  
Elda Del Giudice ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Tumor Cell ◽  
Chemical Structure ◽  
Tumor Cell Proliferation ◽  
New Class

Thioketals as Prevulcanization Inhibitors

1981 ◽  
Vol 54 (5) ◽  
pp. 1132-1148 ◽  
Author(s):  
E. Morita ◽  
A. B. Sullivan
Keyword(s):  
Chemical Shift ◽  
Chemical Structure ◽  
Chemical Nature ◽  
Quaternary Carbon ◽  
New Class ◽  
Rate Of Reaction ◽  
Active Methylene Compounds ◽  
13C Chemical Shift ◽  
Active Methylene

Abstract Thioketals prepared from active methylene compounds are introduced as a new class of nonthioimide prevulcanization inhibitors and compared to other inhibitors in various accelerator systems. The chemical nature of the inhibition by these thioketals has been examined from the interrelations of chemical structure of the thioketals, 13C chemical shift of the quaternary carbon, rate of reaction with 2-mercaptobenzothiazole, and scorch delay.

Some Results of the Spectroscopic Study of Four Close Binary Systems of Early Spectral Types

1965 ◽  
Vol 5 ◽  
pp. 120-130
Author(s):  
T. S. Galkina
Keyword(s):  
Spectroscopic Study ◽  
Spectral Type ◽  
Spectroscopic Investigation ◽  
Binary Systems ◽  
Quantitative Information ◽  
Close Binary ◽  
Physical Parameters ◽  
Absorption And Emission ◽  
Close Binary Systems ◽  
Quantitative Estimates

It is necessary to have quantitative estimates of the intensity of lines (both absorption and emission) to obtain the physical parameters of the atmosphere of components.Some years ago at the Crimean observatory we began the spectroscopic investigation of close binary systems of the early spectral type with components WR, Of, O, B to try and obtain more quantitative information from the study of the spectra of the components.

Polarimetric Observations of Red Variables: A Study of Gas and Particle Interactions

1979 ◽  
Vol 46 ◽  
pp. 386-408 ◽  
Author(s):  
G. V. Coyne ◽  
I. S. McLean
Keyword(s):  
Wavelength Dependence ◽  
Stellar Atmosphere ◽  
Molecular Absorption ◽  
Absorption Bands ◽  
Absorption And Emission ◽  
Mira Variables ◽  
Stellar Photosphere ◽  
Regular Variable ◽  
Red Supergiants ◽  
Balmer Lines

AbstractIn recent years the wavelength, dependence of the polarization in a number of Mira variables, semi-regular variables and red supergiants has been measured with resolutions between 0.3 and 300 A over the range 3300 to 11000 A. Variations are seen across molecular absorption bands, especially TiO bands, and across atomic absorption and emission lines, especially the Balmer lines. In most cases one can ignore or it is possible to eliminate the effects due to interstellar polarization, so that one can study the polarization mechanisms operating in the stellar atmosphere and environment. The stars Omicron Ceti. (Mira), V CVn (semi-regular variable) and Mu Cephei (M2 la), in addition to other stars similar to them, will be discussed in some detail.Models to explain the observed polarization consider that the continuum flux is polarized either by electron, molecular and/or grain scattering or by temperature variations and/or geometrical asymmetries over the stellar photosphere. This polarized radiation is affected by atomic and molecular absorption and emission processes at various geometric depths in the stellar atmosphere and envelope. High resolution spectropolarimetry promises, therefore, to be a power-rul tool for studying stratification effects in these stars.

Inelastic Electron-Matter Interactions

1978 ◽  
Vol 36 (3) ◽  
pp. 259-267
Author(s):  
J. Silcox
Keyword(s):  
Electron Microscope ◽  
Energy Loss ◽  
Chemical Structure ◽  
Inelastic Electron ◽  
Primary Concern ◽  
Unique Probe ◽  
Introductory Paper ◽  
Elastic Processes ◽  
Experimental Level ◽  
Inelastic Processes

In this introductory paper, my primary concern will be in identifying and outlining the various types of inelastic processes resulting from the interaction of electrons with matter. Elastic processes are understood reasonably well at the present experimental level and can be regarded as giving information on spatial arrangements. We need not consider them here. Inelastic processes do contain information of considerable value which reflect the electronic and chemical structure of the sample. In combination with the spatial resolution of the electron microscope, a unique probe of materials is finally emerging (Hillier 1943, Watanabe 1955, Castaing and Henri 1962, Crewe 1966, Wittry, Ferrier and Cosslett 1969, Isaacson and Johnson 1975, Egerton, Rossouw and Whelan 1976, Kokubo and Iwatsuki 1976, Colliex, Cosslett, Leapman and Trebbia 1977). We first review some scattering terminology by way of background and to identify some of the more interesting and significant features of energy loss electrons and then go on to discuss examples of studies of the type of phenomena encountered. Finally we will comment on some of the experimental factors encountered.

In Situ microscopy of the anodic etching of silicon

1995 ◽  
Vol 53 ◽  
pp. 232-233
Author(s):  
Frances M. Ross ◽  
Peter C. Searson
Keyword(s):  
Composite Structures ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Selective Etching ◽  
Silicon On Insulator ◽  
Second Phase ◽  
Porous Layers ◽  
New Class ◽  
Porous Semiconductors

Porous semiconductors represent a relatively new class of materials formed by the selective etching of a single or polycrystalline substrate. Although porous silicon has received considerable attention due to its novel optical properties1, porous layers can be formed in other semiconductors such as GaAs and GaP. These materials are characterised by very high surface area and by electrical, optical and chemical properties that may differ considerably from bulk. The properties depend on the pore morphology, which can be controlled by adjusting the processing conditions and the dopant concentration. A number of novel structures can be fabricated using selective etching. For example, self-supporting membranes can be made by growing pores through a wafer, films with modulated pore structure can be fabricated by varying the applied potential during growth, composite structures can be prepared by depositing a second phase into the pores and silicon-on-insulator structures can be formed by oxidising a buried porous layer. In all these applications the ability to grow nanostructures controllably is critical.

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