We report the synthesis and monolayer properties of conventional and gemini surfactants composed of nicotinic acid-based head groups with an emphasis on assessing how chemical structures affect the behavior of monolayers. A combination of Brewster angle microscopy and atomic force microscopy showed that pure hexadecyl nicotinate formed rippled strands in monolayers, and the gemini correspondents with either flexible or rigid organic linkers resulted in lobed-compact domains, which provides a simple method for patterning air-water and solid-air interfaces. The structural differences between conventional and gemini nicotinic acid-based surfactants could be explained by the interplay between line tension (that favors the formation of circular domains), balanced by dipole−dipole repulsion interaction between headgroups, which promotes extended domains. Miscibility and morphology studies of the modified nicotinic acid surfactants with palmitic acid demonstrated that the properties of mixed films can be controlled by the structure of the former. Excess Gibbs free energies of mixing indicated that the mixed films were less stable than the pure monolayers, and the positive deviations from ideality were the largest in the case of gemini surfactants.
Caffeinium halides were used to catalyse the cycloaddition of CO2 to form cyclic carbonates. The reaction intermediates were isolated and characterized experimentally. The reaction mechanism has been confirmed by DFT calculations.
Herein, a first-time, one pot synthesis of 1,3-bis(3-(1,3-dioxoisoindolin-2-yl)propyl)-1H-imidazol-3-ium bromide (7) which can be considered a vital precursor for the synthesis of highly pure, facile synthesis of task specific ionic liquids...
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