The distinguishing of cis–trans isomers enabled via dielectric/ferroelectric signal feedback in a supramolecular Cu(1,10-phenanthroline)2SeO4·(diol) system

2019 ◽  
Vol 7 (35) ◽  
pp. 11022-11028 ◽  
Author(s):  
Ji-Xing Gao ◽  
Zhong-Xia Wang ◽  
Yuan-Yuan Tang ◽  
Yu-Ling Liu ◽  
Lin Zhou ◽  
...  
Keyword(s):  
Supramolecular System ◽  
Trans Isomers ◽  
System P ◽  
First Time

A supramolecular system is used for the first time to distinguish cis–trans isomers, in which cis- or trans-1,2-cyclohexanediol can be simply recognized via dielectric/ferroelectric responses.

Darstellung, Schwingungsspektren und Normalkoordinatenanalyse von Chloro-Bromo-Rhodaten(III) / Preparation, Vibration Spectra and Normal Coordinate Analysis of Chloro-Bromo-Rhodates(III)

1989 ◽  
Vol 44 (10) ◽  
pp. 1221-1227 ◽  
Author(s):  
W. Preetz ◽  
W. Kuhr
Keyword(s):  
Exchange Chromatography ◽  
Trans Isomers ◽  
Normal Coordinate ◽  
Valence Force ◽  
Trans Influence ◽  
Diethylaminoethyl Cellulose ◽  
Point Groups ◽  
First Time ◽  
Ir And Raman ◽  
Good Agreement

The mixed chloro-bromo-rhodates(III) [RhClnBr6-n]3-, n = 1-5, have been separated for the first time by ion exchange chromatography on diethylaminoethyl-cellulose. Due to the stronger trans-effect of Br, as compared with Cl, on treatment of [RhBr6]3- with conc. HCl nearly pure cis/fac-isomers for n = 2, 3, 4 are formed. The reaction of [RhCl6]3- with conc. HBr yields mixtures of the cis/trans-isomers for n = 2, 4, which cannot be separated, but mer-[RhCl3Br3]3 is formed stereospecifically. The IR and Raman spectra of all isolated mixed ligand complexes are completely assigned according to point groups Oh, D3d, C4v, C3v and C2v, supported by normal coordinate analyses based on a general valence force field. The good agreement of calculated and observed frequencies confirms the assignments. Due to the stronger trans-influence of Br as compared to Cl, in all asymmetric Cl—Rh—Br axes the Rh—Br bonds are strengthened and the Rh—Cl bonds are weakened, indicated by valence force constants for Rh—Br approximately 14% higher, for Rh—Cl 10% lower, as compared with the values calculated for symmetric Br—Rh—Br and Cl—Rh—Cl axes, respectively.

A novel enantioselective synthesis of 6H-dibenzopyran derivatives by combined palladium/norbornene and cinchona alkaloid catalysis

2015 ◽  
Vol 13 (8) ◽  
pp. 2260-2263 ◽  
Author(s):  
Di Xu ◽  
Li Dai ◽  
Marta Catellani ◽  
Elena Motti ◽  
Nicola Della Ca’ ◽  
...  
Keyword(s):  
Catalytic System ◽  
Enantioselective Synthesis ◽  
Cinchona Alkaloid ◽  
System P ◽  
First Time

Chiral dibenzopyran derivatives were obtained by cinchona alkaloid, as organocatalyst, in combination, for the first time, with palladium/norbornene catalytic system.

Systems theory

2017 ◽  
Author(s):  
Anastasia Marinopoulou
Keyword(s):  
Systems Theory ◽  
Multiple Realities ◽  
Traditional Epistemology ◽  
System P ◽  
History Of ◽  
Scientific Truth ◽  
Scientific System ◽  
First Time ◽  
Methodology Of Science ◽  
Scientific Purpose

In his systems’ theory, Luhmann attempts to redefine communication, and associates it with information. For Luhmann, communication is distinct from action (Handeln), and the rationality of the scientific system resides in the notion of Zweck, or in the ends of the sciences towards action. For the first time in the epistemological history of modernity, rationality is understood as a certain scientific purpose of action and not as the critique of scientific truth and validity of reason. The schism that Luhmann brought about between ‘traditional’ epistemology (reconsidered now as novel) and the ‘critical’ theory of science (seen by Luhmann as ‘traditional’) was irredeemable. In the following pages, I maintain that all evidence to the contrary such a divergence was inherent to modernity.Drawing on the Schützean model of multiple realities, Luhmann manages to blur the distinction between instrumentality and rationality by relativizing both within systemic complexity. According to Luhmann, complexity characterizes a multifaceted social system, such as science itself. However, I argue that where complexity, in Luhmann, interprets the systemic, it also employs presentism and partial situationalism to explain the essence and methodology of science as a system.

From Dalton to the Discovery of the Periodic System

2013 ◽  
Author(s):  
Eric Scerri
Keyword(s):  
Periodic System ◽  
Quantitative Data ◽  
Quantitative Characteristic ◽  
Good Deal ◽  
Ancient Greek ◽  
System P ◽  
Quantitative Property ◽  
To Come ◽  
First Time

Our story begins, somewhat arbitrarily, in the English city of Manchester around the turn of the nineteenth century. There, a child prodigy by the name of John Dalton, at the tender age of fifteen is teaching in a school with his older brother. Within a few years, John Dalton’s interests have developed to encompass meteorology, physics, and chemistry. Among the questions that puzzle him is why the various component gases in the air such as oxygen, nitrogen, and carbon dioxide do not separate from each other. Why does the mixture of gases in the air remain as a homogeneous mixture? As a result of pursuing this question, Dalton develops what is to become modern atomic theory. The ultimate constituents of all substances, he supposes, are hard microscopic spheres or atoms that were first discussed by the ancient Greek philosophers and taken up again by modern scientists like Newton, Gassendi, and Boscovich. But Dalton goes a good deal further than all of these thinkers in establishing one all-important quantitative characteristic for each kind of atom, namely its weight. This he does by considering quantitative data on chemical experiments. For example, he finds that the ratio for the weight in which hydrogen and oxygen combine together is one to eight. Dalton assumes that water consists of one atom of each of these two elements. He takes a hydrogen atom to have a weight of 1 unit and therefore reasons that oxygen must have a weight of 8 units. Similarly, he deduces the weights for a number of other atoms and even molecules as we now call them. For the first time the elements acquire a quantitative property, by means of which they may be compared. This feature will eventually lead to an accurate classification of all the elements in the form of the periodic system, but this is yet to come. Before that can happen the notion of atoms provokes tremendous debates and disagreements among the experts of Dalton’s day.

scholarly journals Co-solvent polarity tuned thermochromic nanotubes of cyclic dipeptide–polydiacetylene supramolecular system

RSC Advances ◽  
2020 ◽  
Vol 10 (58) ◽  
pp. 35389-35396
Author(s):  
Mohammed Iqbal Khazi ◽  
Chenikkayala Balachandra ◽  
Geon Shin ◽  
Gang-Hee Jang ◽  
Thimmaiah Govindaraju ◽  
...  
Keyword(s):  
Solvent Polarity ◽  
Supramolecular System ◽  
Cyclic Dipeptide ◽  
System P

Co-solvent controlled fabrication of thermo-responsive chromogenic nanotubes of a cyclic dipeptide–polydiacetylene supramolecular system.

Autocatalytic amplified detection of DNA based on a CdSe quantum dot/folic acid electrochemiluminescence energy transfer system

The Analyst ◽  
2015 ◽  
Vol 140 (1) ◽  
pp. 79-82 ◽  
Author(s):  
Guifen Jie ◽  
Yingqiang Qin ◽  
Qingmin Meng ◽  
Jialin Wang
Keyword(s):  
Energy Transfer ◽  
Folic Acid ◽  
Quantum Dot ◽  
Transfer System ◽  
Cdse Qds ◽  
System P ◽  
Cdse Quantum Dot ◽  
Autocatalytic System ◽  
First Time

Electrochemiluminescence energy transfer from CdSe QDs to folic acid was applied for the first time for amplified detection of DNA by a DNAzyme autocatalytic system.

Successful melting and density measurements of Cu and Ag single crystals with an electrostatic levitation (ESL) system

CrystEngComm ◽  
2014 ◽  
Vol 16 (32) ◽  
pp. 7575-7579 ◽  
Author(s):  
Yong Chan Cho ◽  
Bum-Su Kim ◽  
Hanbyeol Yoo ◽  
Ji Young Kim ◽  
Seunghun Lee ◽  
...  
Keyword(s):  
High Temperature ◽  
Single Crystal ◽  
Single Crystals ◽  
Electrostatic Levitation ◽  
Density Measurements ◽  
System P ◽  
First Time

By using grain-free single crystal specimens, the melting of Cu and Ag using electrostatic levitation (ESL) and obtaining their high-temperature densities were accomplished for the first time.

Rhodium-catalyzed intermolecular C(sp3)–H amination in a purely aqueous system

2018 ◽  
Vol 20 (1) ◽  
pp. 113-117 ◽  
Author(s):  
Xunbo Lu ◽  
Yufeng Shi ◽  
Fangrui Zhong
Keyword(s):  
Aqueous System ◽  
System P ◽  
First Time

An efficient Rh-catalyzed intermolecular C(sp3)–H amination in a purely aqueous system is developed for the first time.

A simple ternary non-ionic templating system for preparation of complex hierarchically meso–mesoporous silicas with 3D-interconnected large mesopores

2014 ◽  
Vol 2 (15) ◽  
pp. 5363-5370 ◽  
Author(s):  
Wei Wang ◽  
Huan Qi ◽  
Haibo Long ◽  
Xiaoyang Wang ◽  
Hongqiang Ru
Keyword(s):  
Silica Particles ◽  
Mesoporous Silicas ◽  
System P ◽  
Large Mesopores ◽  
First Time ◽  
Mesoporous Structures

It is for the first time demonstrated that clew-like silica particles with complex hierarchically meso–mesoporous structures can be prepared via a simple TEOS/HCl(aq.)/P123 ternary non-ionic templating system.

Efficient mineralization of ciprofloxacin using a 3D CexZr1−xO2/RGO composite cathode

2017 ◽  
Vol 4 (2) ◽  
pp. 425-436 ◽  
Author(s):  
Yi Li ◽  
Yanan Li ◽  
Baorong Xie ◽  
Jingjing Han ◽  
Sihui Zhan ◽  
...  
Keyword(s):  
Self Assembly ◽  
Composite Cathode ◽  
Composite Electrodes ◽  
Assembly Method ◽  
System P ◽  
First Time ◽  
Fenton System

3D columnar CexZr1−xO2/RGO composite electrodes were prepared based on a hydrothermal self-assembly method and were used as cathodes to degrade ciprofloxacin (CIP) for the first time in an electro-Fenton system.

Sign in / Sign up

Export Citation Format

Share Document