Surfactant quaternary ammonium hydrotris(1-pyrazolyl)borates
Quaternary ammonium surfactants with the hydrotris(1-pyrazolyl)borate anion as an unusual counterion were prepared and characterized. Dodecyl- (1a), tetradecyl- (1b), and hexadecyltrimethylammonium hydrotris(1-pyrazolyl)borate (1c), as well as didodecyldimethylammonium hydrotris(1-pyrazolyl)borate (...
| Veröffentlicht in: | Langmuir : the ACS journal of surfaces and colloids. - 1992. - 21(2005), 21 vom: 11. Okt., Seite 9440-5 |
|---|---|
| 1. Verfasser: | |
| Weitere Verfasser: | , , , , |
| Format: | Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2005
|
| Zugriff auf das übergeordnete Werk: | Langmuir : the ACS journal of surfaces and colloids |
| Schlagworte: | Journal Article |
| Zusammenfassung: | Quaternary ammonium surfactants with the hydrotris(1-pyrazolyl)borate anion as an unusual counterion were prepared and characterized. Dodecyl- (1a), tetradecyl- (1b), and hexadecyltrimethylammonium hydrotris(1-pyrazolyl)borate (1c), as well as didodecyldimethylammonium hydrotris(1-pyrazolyl)borate (2), were prepared by metathesis reactions with the corresponding quaternary ammonium bromides and potassium hydrotris(1-pyrazolyl)borate (4). Although the surfactants have limited stabilities in water at 23 degrees C, they were characterized by measurement of their Krafft temperatures and critical aggregation concentrations. (1)H NMR spectroscopy suggested that the single-chain surfactants 1 form small aggregates in water and revealed an association of the quaternary ammonium and hydrotris(1-pyrazolyl)borate ions above their critical aggregation concentrations. Cryo-etch high-resolution scanning electron microscopy indicated that 1a and 1b most likely form segregation patterns upon plunge-freezing and cryo-etching of their aqueous solutions, and a single-crystal X-ray diffraction study of 1a was performed |
|---|---|
| Beschreibung: | Date Completed 10.04.2007 Date Revised 06.10.2005 published: Print Citation Status PubMed-not-MEDLINE |
| ISSN: | 1520-5827 |