Harnstoffe als Lösungsmittel in der chemischen Forschung

Abstract

N-Alkylierte Harnstoffe, auch cyclische Derivate, sind gut in reiner Form zu erhalten. Diese stabilen Verbindungen werden aufgrund ihres hohen Losungsvermogens, ihres grofien Flussigkeitsbereichs sowie der giinstigen Dielektrizitatskonstanten und Dipolmomente bereits als Losungsmittel fur technische Zwecke genutzt. Eine breitere Anwendung als Reaktionsmedien fur elektrochemische und analytische Untersuchungen zeichnet sich ab.

Cyclic ureas as solvents for esterification of poly(vinyl alcohol) and vinyl acetate‐vinyl alcohol copolymers with acid chlorides

“…DMPU and NMP are dipolar aprotic solvents with high dipole moments,27, 28 attributed to the partial double bond character of its carbonyl carbon–nitrogen bond (Scheme ). Comparison of the dipole moments and dielectric constants of both shows DMPU has the highest dipole moment and dielectric constant (Table VII).…”

Coordination chemistry effects of the space-demanding solvent molecule N,N′-dimethylpropyleneurea

“…Efficient safety glasses and gloves should always be used when handling metal perchlorates and perchloric acid. 4), [Sr(dmpu) 6 ] (CF 3 SO 3 ) 2 (5), [Ba(dmpu) 6 ](CF 3 SO 3 ) 2 (6), [Sc(dmpu) 6 ]I 3 (7), [Pr(dmpu) 6 ]I(I 3 ) 2 (8) and [CoBr 2 (dmpu) 2 ] (9) of X-ray quality were obtained after dissolving the anhydrous salt in freshly distilled dmpu, gently heating to ca. 310 K and allowing to slowly cool to room temperature.…”

“…It is used as a versatile solvent for the synthesis of pharmaceuticals and agrochemicals, dyestuffs and polymers, epoxides, polyimides, and other engineering resins, and for BTX extraction, spinning, dyeing of fibers, etc. [3][4][5][6][7] The high relative permittivity is the reason for its excellent dissolving properties, not only for organic compounds but also for inorganic compounds due to its ability to form stable metal dmpu complexes and compounds. 8 Furthermore, the closeness of the two methyl groups to the oxygen donor atom leads to the dmpu molecule demanding a lot of space at coordination to metal ions, often forcing them to adopt lower coordination numbers than in most other oxygen donor solvents without such steric restrictions, Table S1 (ESI).…”

“…Crystallographic measurement data for [Mg(dmpu) 5 ]I 2(1), [Ca(dmpu) 6 ]I 2(2), [Ca(dmpu) 6 ](ClO 4 ) 2(3), [Ca(dmpu) 6 ](CF 3 SO 3 ) 2(4) [Sr(dmpu) 6 ] (CF 3 SO 3 ) 2(5), [Ba(dmpu) 6 ](CF 3 SO 3 ) 2(6), [Sc(dmpu) 6 ]I 3(7), [Pr(dmpu) 6 ]I(I 3 ) 2(8) and [CoBr 2 (dmpu) 2 ] (9) 60 I 2 N 10 O 2 Mg C 36 H 72 I 2 N 12 O 6 Ca C 36 H 72 Cl 2 N 12 O 14 Ca C 38 H 72 F 6 N 12 O 12 Ca C 38 H 72 F 6 N 12 O 12 Sr…”

Family Tree for Aqueous Organic Redox Couples for Redox Flow Battery Electrolytes: A Conceptual Review

“…The high thermal capacity of water is also beneficial for simplified heat management (heat removal from the battery cell) when compared to Li-ion cells of hydrogen fuel cells. [8][9][10][11][12] of typical organic solvents in electrochemistry arranged according to their permeability (ε).…”