A switchable-hydrophilicity solvent (SHS) is a solvent that in one state forms a biphasic mixture with water but can be reversibly switched to another state that is miscible with water. All of the amine SHSs that we have reported previously lie within a particular basicity and hydrophilicity range (9.5 < pKaH < 11 and 1.0 < log Kow < 2.5, respectively). We report an extension of this range by altering the pressure of CO2 as well as the water : SHS volume ratio used in the process. Increasing the pressure of CO2 and/or the water : amine volume ratio allows some amines with pKaH < 9.5 or log Kow > 2.5 to function as SHSs.
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Carbohydr Polym
January 2025
Polymer Institute of the Slovak Academy of Sciences, Dúbravská cesta 9, 845 41 Bratislava, Slovakia. Electronic address:
DMTMM-mediated amidation of sodium alginate is one of the methods used for the chemical modification of alginate with amines. However, there is a limited understanding of how the reaction conditions, particularly the pH value, influence the conjugation efficiency (CE) and the resulting degree of substitution (DS). In this study, we investigated the effect of the pH during the reaction, focusing on both neutral and weakly basic conditions, using water and buffer as solvents.
View Article and Find Full Text PDFChemistry
January 2025
Institute of Chemistry, University of Tartu, Ravila 14a Str, Tartu, 50411, Estonia.
Despite the numerous published syntheses and applications of sulfoximines, very few studies describe their physico-chemical properties and in particular their acidic, basic and lipophilic or hydrophilic characters. We report for the first time the acidity values (pK) of fluorinated sulfoximines in water and in acetonitrile, as well as the basicity (pK) measurements of fluorinated and non-fluorinated sulfoximines in acetonitrile. The same sulfoximine library was also studied in terms of lipophilicity with measurement of the Hansch parameters of the sulfoximine moieties.
View Article and Find Full Text PDFDalton Trans
August 2024
Institute of Chemistry, University of Tartu, Ravila 14a, Tartu 50411, Estonia.
Phosphanes play an important role in various applications, serving as a class of organic bases with basicities spanning more than 30 orders of magnitude. Accessing comprehensive basicity data for phosphanes has been challenging due to scattered information across multiple sources and notable gaps in the existing data. In this report, we present basicities (p values) of a diverse set of phosphanes, both newly measured or calculated and collected from the literature.
View Article and Find Full Text PDFPhys Chem Chem Phys
April 2024
Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario, Canada K7L 2S8.
Most CO-responsive systems operate by using a base in water that is expected to be mostly deprotonated when under an atmosphere of air and mostly protonated under an atmosphere of CO. This concept has led to the development of many different CO-responsive materials such as solvents, polymers, surfactants, and solutes. As CO-responsive materials research continues, more complex systems may be developed, including systems containing two different bases with different basicities.
View Article and Find Full Text PDFWe developed a novel and efficient sequential one-pot synthesis of selenosulfides via a base-catalyzed methodology utilizing readily available starting compounds, under mild reaction conditions. This method eliminated the need for excess oxidants or additives and simplified the synthesis procedure. Furthermore, organic amine bases served as exceptional catalysts for synthesizing the target products.
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