scholarly journals Study of interactions between Brønsted acids and triethylphosphine oxide in solution by 31P NMR: evidence for 2 : 1 species

2020 ◽  
Vol 22 (42) ◽  
pp. 24351-24358
Author(s):  
Elisabet Pires ◽  
José M. Fraile
Keyword(s):  
Chemical Shift ◽  
31P Nmr ◽  
Bronsted Acids ◽  
Acid Interaction ◽  
Molar Ratios ◽  
Triethylphosphine Oxide

31P chemical shift of TEPO–acid 1 : 1 species correlates with pKa. The evolution at higher molar ratios indicate a second TEPO–acid interaction.

scholarly journals Mixed Chlorometallate Ionic Liquids as C4 Alkylation Catalysts: A Quantitative Study of Acceptor Properties

Catalysts ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 498
Author(s):  
Xiaoying Pang ◽  
Ying Liu ◽  
Juanfang Wang
Keyword(s):  
Ionic Liquids ◽  
Lewis Acidity ◽  
Alkylation Reaction ◽  
Triethylamine Hydrochloride ◽  
Metal Chlorides ◽  
Molar Ratios ◽  
Anionic Species ◽  
Triethylphosphine Oxide ◽  
The Relationship ◽  
Acceptor Numbers

The acceptor properties of mixed chlorometallate ionic liquids for isobutane-butene alkylation (C4 alkylation) reaction were studied. These ionic liquids were prepared by mixing metal chlorides with either triethylamine hydrochloride or 1-butyl-3-methylimidazolium chloride in various molar ratios. Using triethylphosphine oxide as a probe, Gutmann Acceptor Numbers (AN) of the catalysts were determined, and the Lewis acidity of mixed chlorometallate ionic liquids was quantitatively measured. Additionally, AN value was developed to determine the relationship between Lewis acidity and catalytic selectivity. The favorite AN value for the C4 alkylation reaction should be around 93.0. The [(C2H5)3NH]Cl–AlCl3−CuCl appears to be more Lewis acidity than that of [(C2H5)3NH]Cl–AlCl3. The correlation of the acceptor numbers to speciation of the mixed chlorometallate ionic liquids has also been investigated. [AlCl4]−, [Al2Cl7]−, and [MAlCl5]− (M = Cu, Ag) are the main anionic species of the mixed chlorometallate ILs. While the presence of [(C2H5)3N·M]+ cation always decreases the acidity of the [(C2H5)3NH]Cl−AlCl3−MCl ionic liquids.

Local-structure effects on 31P NMR chemical shift tensors in solid state

2019 ◽  
Vol 150 (14) ◽  
pp. 144706 ◽  
Author(s):  
Ivan Yu. Chernyshov ◽  
Mikhail V. Vener ◽  
Ilya G. Shenderovich
Keyword(s):  
Solid State ◽  
Chemical Shift ◽  
Local Structure ◽  
31P Nmr ◽  
Nmr Chemical Shift ◽  
Chemical Shift Tensors

scholarly journals Ab initio computation for solid-state 31P NMR of inorganic phosphates: revisiting X-ray structures

2019 ◽  
Vol 21 (19) ◽  
pp. 10070-10074 ◽  
Author(s):  
Kartik Pilar ◽  
Zeyu Deng ◽  
Molleigh B. Preefer ◽  
Joya A. Cooley ◽  
Raphaële Clément ◽  
...  
Keyword(s):  
Solid State ◽  
Chemical Shift ◽  
Ab Initio ◽  
Crystal Structures ◽  
31P Nmr ◽  
Geometry Optimization ◽  
Chemical Shift Tensors ◽  
X Ray ◽  
Ab Initio Computation ◽  
Inorganic Phosphates

The complete 31P NMR chemical shift tensors for 22 inorganic phosphates obtained from ab initio computation are found to correspond closely to experimentally obtained parameters. The cases where correspondence is significantly improved upon geometry optimization point to the crystal structures requiring correction.

scholarly journals H/D Isotope Effects on 1H-NMR Chemical Shifts in Cyclic Heterodimers and Heterotrimers of Phosphinic and Phosphoric Acids

Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1907 ◽  
Author(s):  
Valeriia V. Mulloyarova ◽  
Daria O. Ustimchuk ◽  
Aleksander Filarowski ◽  
Peter M. Tolstoy
Keyword(s):  
Chemical Shift ◽  
Low Temperature ◽  
Hydrogen Bonds ◽  
1H Nmr ◽  
31P Nmr ◽  
Chemical Shifts ◽  
Isotope Effects ◽  
Proton Chemical Shift ◽  
Steric Factors ◽  
Solvent Formation

Hydrogen-bonded heterocomplexes formed by POOH-containing acids (diphenylphosphoric 1, dimethylphosphoric 2, diphenylphosphinic 3, and dimethylphosphinic 4) are studied by the low-temperature (100 K) 1H-NMR and 31P-NMR using liquefied gases CDF3/CDF2Cl as a solvent. Formation of cyclic dimers and cyclic trimers consisting of molecules of two different acids is confirmed by the analysis of vicinal H/D isotope effects (changes in the bridging proton chemical shift, δH, after the deuteration of a neighboring H-bond). Acids 1 and 4 (or 1 and 3) form heterotrimers with very strong (short) H-bonds (δH ca. 17 ppm). While in the case of all heterotrimers the H-bonds are cyclically arranged head-to-tail, ···O=P–O–H···O=P–O–H···, and thus their cooperative coupling is expected, the signs of vicinal H/D isotope effects indicate an effective anticooperativity, presumably due to steric factors: when one of the H-bonds is elongated upon deuteration, the structure of the heterotrimer adjusts by shortening the neighboring hydrogen bonds. We also demonstrate the formation of cyclic tetramers: in the case of acids 1 and 4 the structure has alternating molecules of 1 and 4 in the cycle, while in case of acids 1 and 3 the cycle has two molecules of 1 followed by two molecules of 3.

scholarly journals 31P NMR correlation maps of 18O/16O chemical shift isotopic effects for phosphometabolite labeling studies

2011 ◽  
Vol 50 (3) ◽  
pp. 237-245 ◽  
Author(s):  
Nenad Juranić ◽  
Emirhan Nemutlu ◽  
Song Zhang ◽  
Petras Dzeja ◽  
Andre Terzic ◽  
...  
Keyword(s):  
Chemical Shift ◽  
31P Nmr ◽  
Isotopic Effects
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