Changes in microstructure of two ammonium-based protic ionic liquids proved by in situ variable-temperature 1 H NMR spectroscopy: influence of anion

2017 ◽  
Vol 56 (2) ◽  
pp. 73-79 ◽  
Author(s):  
Xiaochen Tang ◽  
Yingjie Xu ◽  
Xiao Zhu ◽  
Yueqing Lu
2017 ◽  
Vol 19 (36) ◽  
pp. 25033-25043 ◽  
Author(s):  
M. Lozynski ◽  
J. Pernak ◽  
Z. Gdaniec ◽  
B. Gorska ◽  
F. Béguin

The self-assembly of triethylammonium bis(trifluoromethylsulfonyl)imide, i.e. [(C2H5)3NH][TFSI], in chloroform and aqueous solutions has been investigated using 1H NMR spectroscopy and computational (DFT/PCM prediction) methods.


2018 ◽  
Vol 8 (24) ◽  
pp. 6316-6329
Author(s):  
Jorge Pèrez-Miqueo ◽  
Virginia San Nacianceno ◽  
F. Borja Urquiola ◽  
Zoraida Freixa
Keyword(s):  

In situ1H NMR spectroscopy reveals a cascade mechanism for the hydrosilylation of enolizable imines catalyzed by iridium(iii) metallacycles.


2014 ◽  
Vol 192 ◽  
pp. 55-58 ◽  
Author(s):  
Ralf Giernoth ◽  
Andreas Bröhl ◽  
Martin Brehm ◽  
Yves Lingscheid

2021 ◽  
Author(s):  
Benjamin Spitzbarth ◽  
Rienk Eelkema

We demonstrate that the species present in the equilibrium of DCv ureas can be employed in reaction cascades and as triggered organocatalysts. Easily controllable stimuli like heat or addition of water shift the equilibrium towards isocyanate and free base which can function as an in situ released reagent, both catalytically and in an equimolar fashion in different reactions. While applying heat to the system leads to a reversible liberation of amine base, addition of water makes this release irreversible. We demonstrate this application of DCv ureas with two examples via <sup>1</sup>H-NMR spectroscopy. Firstly, we use the liberated base to activate a protected organocatalyst for acylhydrazone formation. Secondly, this base can be employed to trigger the release of nitrile-N-oxides from chlorooximes, which can react with 4-arm PEG-thiols to form a thiohydroximate polymer gel. These findings show the utility of DCv hindered ureas beyond their application in self-healing.


2019 ◽  
Vol 10 (39) ◽  
pp. 8955-8963 ◽  
Author(s):  
Kijung Jung ◽  
Tonia S. Ahmed ◽  
Jaeho Lee ◽  
Jong-Chan Sung ◽  
Hyeyun Keum ◽  
...  

Herein, we demonstrate the first example of living β-selective CP by rational engineering of the steric factor on monomer or catalyst structures, along with a mechanistic investigation by in situ kinetic studies using 1H NMR spectroscopy.


1979 ◽  
Vol 44 (2) ◽  
pp. 558-588 ◽  
Author(s):  
Zdeněk Samek ◽  
Miloš Buděšínský

The application possibilities of the in situ reactions of trichloroacetyl isocyanate (TAI method) to structural assignment of alcohols by means of 1H NMR spectroscopy are critically evaluated. The possibilities of TAI acylations in various solvents are demonstrated and the reactivity of various functional groups, potentially complicating or extending the applications of TAI, is discussed. In addition to their use in structural analysis such reactions also can serve as model experiments for preparative purposes.


1980 ◽  
Vol 45 (10) ◽  
pp. 2784-2803 ◽  
Author(s):  
Miloš Buděšínský ◽  
Zdeněk Samek ◽  
Miloš Tichý

The in situ reaction of amines with trichloroacetyl isocyanate (TAI) in the NMR sample tube was investigated as a tool in structural analysis by means of 1H NMR spectroscopy. Preferred conformations of the adducts were suggested which explain different behaviour of NH protons and the induced CH protons shifts. On the example of amino alcohols it was shown how to use the TAI method in combination with other in situ reactions (protonation, acetylation, trifluoroacetylation) for simultaneous differentiation between functional groups in polyfunctional molecules.


Sign in / Sign up

Export Citation Format

Share Document