B-11-NMR shielding effects in the closo borane series: sensitivity of shifts and their additivity

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388980%3A_____%2F17%3A00482740" target="_blank" >RIV/61388980:_____/17:00482740 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1039/c7nj02689g" target="_blank" >http://dx.doi.org/10.1039/c7nj02689g</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/c7nj02689g" target="_blank" >10.1039/c7nj02689g</a>

Jazyk výsledku

angličtina

Název v původním jazyce

B-11-NMR shielding effects in the closo borane series: sensitivity of shifts and their additivity

Popis výsledku v původním jazyce

An Alpha Shift Correlation (ASC) method is used to assess quantitatively NMR shielding effects in a series of halogen derivatives of closo-borane dianions, [X-m-BnHn-m](2-). There is a simple linear correlation between the universal alpha(ref) shifts and those induced by the substituent X in all positions of the closo borane cluster: Delta delta(B-11) = k.alpha(ref) (where Delta delta = delta(s) delta(p) and subscripts s and p denote the substituted and parent derivatives, respectively, k = correlation slope). The sensitivity of the chemical shift in a given cage position to X-changes is defined by the g factor (g = gradient = k x 10(2)). The ASC approach revealed that the alpha-deshielding effect in the monosubstituted anionic [X-BnHn-1](2-) series decreases in the order of n: 6 > 12 > 10 > 9, and is dependent on the cage type and electron density at the substituted vertex. The sensitivity (g) in individual cluster positions to substituent changes decreases in the order alpha >> A > b > gamma and is of approximately additive character. The most important feature of the unsubstituted sphere is the antipodal (A) effect showing a g-trend inversed to that observed at the substituted alpha-sites. Of interest are also the remarkable pseudo-A and trans-gamma shielding effects in the 9- and 10-vertex anionic series.

Název v anglickém jazyce

B-11-NMR shielding effects in the closo borane series: sensitivity of shifts and their additivity

Popis výsledku anglicky

An Alpha Shift Correlation (ASC) method is used to assess quantitatively NMR shielding effects in a series of halogen derivatives of closo-borane dianions, [X-m-BnHn-m](2-). There is a simple linear correlation between the universal alpha(ref) shifts and those induced by the substituent X in all positions of the closo borane cluster: Delta delta(B-11) = k.alpha(ref) (where Delta delta = delta(s) delta(p) and subscripts s and p denote the substituted and parent derivatives, respectively, k = correlation slope). The sensitivity of the chemical shift in a given cage position to X-changes is defined by the g factor (g = gradient = k x 10(2)). The ASC approach revealed that the alpha-deshielding effect in the monosubstituted anionic [X-BnHn-1](2-) series decreases in the order of n: 6 > 12 > 10 > 9, and is dependent on the cage type and electron density at the substituted vertex. The sensitivity (g) in individual cluster positions to substituent changes decreases in the order alpha >> A > b > gamma and is of approximately additive character. The most important feature of the unsubstituted sphere is the antipodal (A) effect showing a g-trend inversed to that observed at the substituted alpha-sites. Of interest are also the remarkable pseudo-A and trans-gamma shielding effects in the 9- and 10-vertex anionic series.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10402 - Inorganic and nuclear chemistry

Projekt

<a href="/cs/project/GA16-01618S" target="_blank" >GA16-01618S: Desetivrcholové dikarbaboranové molekulární útvary vytvořené alkylací</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2017

Kód důvěrnosti údajů

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

Název periodika

New Journal of Chemistry

ISSN

1144-0546

e-ISSN

—

Svazek periodika

41

Číslo periodika v rámci svazku

23

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

5

Strana od-do

14452-14456

Kód UT WoS článku

000415839300054

EID výsledku v databázi Scopus

2-s2.0-85034851776