Self-diffusion of phosphonium Bis(Salicylato)Borate ionic liquid in pores of Vycor porous glass

© 2016 Elsevier Inc. All rights reserved.1H NMR pulsed field gradient was used to study self-diffusion of a phosphonium bis(salicylato)borate ionic liquid ([P6,6,6,14][BScB]) in the pores of Vycor porous glass at 296 K. Confinement in pores increases diffusion coefficients of the ions by a factor of 35. However, some [P6,6,6,14][BScB] ions demonstrated apparent diffusion coefficients much lower than their mean values, which may be due to partially restricted diffusion of the ions. We suggest that this fraction corresponds to areas where ions are confined by pore 'necks' (micropores) and empty voids. Heating of the ionic liquid/Vycor system at 330 K led to a change in the diffusivity of the ions, because of their redistribution in the pores. The size of the bounded regions is on the order of 1 μm, as estimated from the dependence of the ion diffusivity on the diffusion time

Reaction of 2-acetyl-5-methyl-2H-1,2,3-diazaphosphole with butane-2,3-diol

The reaction of 2-acetyl-5-methyl-2H-1,2,3-diazaphosphole with (rac)-butane-2,3-diol at temperatures below 0 °C leads to the formation of a hydrospirophosphorane containing both a diazaphospholene and a dioxaphospholane ring system and a β-hydroxy-alkoxy-1,2,3-diazaphospholene. On heating, these products form a hydrospirotetraoxaphosphorane, its tautomeric monocyclic β-hydroxyalkylphosphite and N-acetyl-N'-isopropylidene-hydrazine

Self-diffusion and interactions in mixtures of imidazolium bis(mandelato)borate ionic liquids with polyethylene glycol: ¹H NMR study

Copyright © 2015 John Wiley & Sons, Ltd. We used 1H nuclear magnetic resonance pulsed-field gradient to study the self-diffusion of polyethylene glycol (PEG) and ions in a mixture of PEG and imidazolium bis(mandelato)borate ionic liquids (ILs) at IL concentrations from 0 to 10 and temperatures from 295 to 370. PEG behaves as a solvent for these ILs, allowing observation of separate lines in 1H NMR spectra assigned to the cation and anion as well as to PEG. The diffusion coefficients of PEG, as well as the imidazolium cation and bis(mandelato)borate (BMB) anion, differ under all experimental conditions tested. This demonstrates that the IL in the mixture is present in at least a partially dissociated state, while the lifetimes of the associated states of the ions and ions with PEG are less than 30ms. Generally, increasing the concentration of the IL leads to a decrease in the diffusion coefficients of PEG and both ions. The diffusion coefficient of the anion is less than that of the cation; the molecular mass dependence of diffusion of ions can be described by the Stokes-Einstein model. NMR chemical shift alteration analysis showed that the presence of PEG changes mainly the chemical shifts of protons belonging to imidazole ring of the cation, while chemical shifts of protons of anions and PEG remain unchanged. This demonstrated that the imidazolium cation interacts mainly with PEG, which most probably occurs through the oxygen of PEG and the imidazole ring. The BMB anion does not strongly interact with PEG, but it may be indirectly affected by PEG through interaction with the cation, which directly interacts with PEG

Self-diffusion and interactions in mixtures of imidazolium bis(mandelato)borate ionic liquids with polyethylene glycol: 1H NMR study

© 2015 John Wiley & Sons, Ltd. We used 1H nuclear magnetic resonance pulsed-field gradient to study the self-diffusion of polyethylene glycol (PEG) and ions in a mixture of PEG and imidazolium bis(mandelato)borate ionic liquids (ILs) at IL concentrations from 0 to 10wt% and temperatures from 295 to 370K. PEG behaves as a solvent for these ILs, allowing observation of separate lines in 1H NMR spectra assigned to the cation and anion as well as to PEG. The diffusion coefficients of PEG, as well as the imidazolium cation and bis(mandelato)borate (BMB) anion, differ under all experimental conditions tested. This demonstrates that the IL in the mixture is present in at least a partially dissociated state, while the lifetimes of the associated states of the ions and ions with PEG are less than ~30ms. Generally, increasing the concentration of the IL leads to a decrease in the diffusion coefficients of PEG and both ions. The diffusion coefficient of the anion is less than that of the cation; the molecular mass dependence of diffusion of ions can be described by the Stokes-Einstein model. NMR chemical shift alteration analysis showed that the presence of PEG changes mainly the chemical shifts of protons belonging to imidazole ring of the cation, while chemical shifts of protons of anions and PEG remain unchanged. This demonstrated that the imidazolium cation interacts mainly with PEG, which most probably occurs through the oxygen of PEG and the imidazole ring. The BMB anion does not strongly interact with PEG, but it may be indirectly affected by PEG through interaction with the cation, which directly interacts with PEG

An experimental and theoretical study of intramolecular cyclization of phosphorylated thioureas

New 1,3,2-thiazaphospholines were prepared, and their steric and electronic structures were examined. The steric and electronic structure of N-[(O-methyl)chloromethylthiophosphoryl]thiourea and the pathways of their intramolecular cyclization and rearrangement were studied by ab initio and semiempirical methods. The influence exerted by the conformational factors in thiourea and in the anion formed from it under the conditions of base catalysis on the direction of the reactions involving these species was revealed, and the structure of intermediate complexes and the final products was determined. ©2005 Pleiades Publishing, Inc

Self-diffusion of phosphonium Bis(Salicylato)Borate ionic liquid in pores of Vycor porous glass

© 2016 Elsevier Inc. All rights reserved.1H NMR pulsed field gradient was used to study self-diffusion of a phosphonium bis(salicylato)borate ionic liquid ([P6,6,6,14][BScB]) in the pores of Vycor porous glass at 296 K. Confinement in pores increases diffusion coefficients of the ions by a factor of 35. However, some [P6,6,6,14][BScB] ions demonstrated apparent diffusion coefficients much lower than their mean values, which may be due to partially restricted diffusion of the ions. We suggest that this fraction corresponds to areas where ions are confined by pore 'necks' (micropores) and empty voids. Heating of the ionic liquid/Vycor system at 330 K led to a change in the diffusivity of the ions, because of their redistribution in the pores. The size of the bounded regions is on the order of 1 μm, as estimated from the dependence of the ion diffusivity on the diffusion time

Self-diffusion of phosphonium Bis(Salicylato)Borate ionic liquid in pores of Vycor porous glass

© 2016 Elsevier Inc. All rights reserved.1H NMR pulsed field gradient was used to study self-diffusion of a phosphonium bis(salicylato)borate ionic liquid ([P6,6,6,14][BScB]) in the pores of Vycor porous glass at 296 K. Confinement in pores increases diffusion coefficients of the ions by a factor of 35. However, some [P6,6,6,14][BScB] ions demonstrated apparent diffusion coefficients much lower than their mean values, which may be due to partially restricted diffusion of the ions. We suggest that this fraction corresponds to areas where ions are confined by pore 'necks' (micropores) and empty voids. Heating of the ionic liquid/Vycor system at 330 K led to a change in the diffusivity of the ions, because of their redistribution in the pores. The size of the bounded regions is on the order of 1 μm, as estimated from the dependence of the ion diffusivity on the diffusion time

Reaction of 2-acetyl-5-methyl-2H-1,2,3-diazaphosphole with butane-2,3-diol

The reaction of 2-acetyl-5-methyl-2H-1,2,3-diazaphosphole with (rac)-butane-2,3-diol at temperatures below 0 °C leads to the formation of a hydrospirophosphorane containing both a diazaphospholene and a dioxaphospholane ring system and a β-hydroxy-alkoxy-1,2,3-diazaphospholene. On heating, these products form a hydrospirotetraoxaphosphorane, its tautomeric monocyclic β-hydroxyalkylphosphite and N-acetyl-N'-isopropylidene-hydrazine