Variation of the stereoparameters for description geometry of calix[4]arenes - more suitable solution for "flat systems"

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F18%3A10376996" target="_blank" >RIV/00216208:11310/18:10376996 - isvavai.cz</a>

Výsledek na webu

<a href="http://chemistry-vestnik.ksu.kz/apart/2018-90-2/3.pdf" target="_blank" >http://chemistry-vestnik.ksu.kz/apart/2018-90-2/3.pdf</a>

DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Variation of the stereoparameters for description geometry of calix[4]arenes - more suitable solution for "flat systems"

Popis výsledku v původním jazyce

This article deals with a variation of previously introduced parameters alpha, beta, and delta which were used to describing the all possible conformations of these compounds, cone, partial cone, 1,2- and 1,3-alternate conformers of methylene- and heteroatom-bridged calix[4] arenes. Usefulness of these parameters alpha, beta, delta have been already demonstrated, but, it seems, to be more suitable to do any variations them for flat systems. The background for the parameters a, , d lies in the representation of the scale of the angles of the calix[4] arene rings towards the reference plane. The original scale 0 degrees - 360 degrees for these angles depicts very well the differences between the calix[4 ] arene conformations but has two significant disadvantages. The first one is the discontinuity of the scale. The angles alpha(i) range approximately from 0 degrees to 110 degrees and from 250 degrees to 360 degrees because of the sterical hindrance that would occur should the calixarene phenyl ring enter the cavity. The second disadvantage is the discontinuity at the point alpha(i) = 0 degrees, it means the case of flat systems. These flat systems are usually the &apos;transitions states&apos; between the calixarene conformations and cannot be observed using parameters alpha, beta, delta. To eliminate the difficulties in describing the &apos;transition states&apos; between the calix[4] arene conformations caused by the discontinuities of the original scale, the new scale should be introduced. New parameters alpha &apos;, beta &apos;,delta &apos; were introduced by subtracting 360 degrees for each &apos;negative&apos; ring present in the structure (one for partial cone conformers, two for 1,2- and 1,3-alternate conformers); after the parameters alpha, beta, delta are calculated.

Název v anglickém jazyce

Variation of the stereoparameters for description geometry of calix[4]arenes - more suitable solution for "flat systems"

Popis výsledku anglicky

This article deals with a variation of previously introduced parameters alpha, beta, and delta which were used to describing the all possible conformations of these compounds, cone, partial cone, 1,2- and 1,3-alternate conformers of methylene- and heteroatom-bridged calix[4] arenes. Usefulness of these parameters alpha, beta, delta have been already demonstrated, but, it seems, to be more suitable to do any variations them for flat systems. The background for the parameters a, , d lies in the representation of the scale of the angles of the calix[4] arene rings towards the reference plane. The original scale 0 degrees - 360 degrees for these angles depicts very well the differences between the calix[4 ] arene conformations but has two significant disadvantages. The first one is the discontinuity of the scale. The angles alpha(i) range approximately from 0 degrees to 110 degrees and from 250 degrees to 360 degrees because of the sterical hindrance that would occur should the calixarene phenyl ring enter the cavity. The second disadvantage is the discontinuity at the point alpha(i) = 0 degrees, it means the case of flat systems. These flat systems are usually the &apos;transitions states&apos; between the calixarene conformations and cannot be observed using parameters alpha, beta, delta. To eliminate the difficulties in describing the &apos;transition states&apos; between the calix[4] arene conformations caused by the discontinuities of the original scale, the new scale should be introduced. New parameters alpha &apos;, beta &apos;,delta &apos; were introduced by subtracting 360 degrees for each &apos;negative&apos; ring present in the structure (one for partial cone conformers, two for 1,2- and 1,3-alternate conformers); after the parameters alpha, beta, delta are calculated.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

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OECD FORD obor

10402 - Inorganic and nuclear chemistry

Projekt

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Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2018

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Bulletin of Karaganda State University, Series chemistry

ISSN

2518-718X

e-ISSN

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Svazek periodika

neuveden

Číslo periodika v rámci svazku

90

Stát vydavatele periodika

KZ - Republika Kazachstán

Počet stran výsledku

8

Strana od-do

23-30

Kód UT WoS článku

000438647100003

EID výsledku v databázi Scopus

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