Coupling of epoxides and carbon dioxide catalyzed by Br?nsted acid ionic liquids
A series of Br?nsted acid ionic liquids (BAILs) containing a long chain Br?nsted acid site in the cationic part and a Lewis basic site in the anionic part were designed, synthesized, and used as catalyst for the coupling of epoxides and carbon dioxide to cyclic carbonates without a co-catalyst or co-solvent. The effects of catalyst structure and other parameters on the catalytic performance were investigated. The long chain 2-(N,N-dimethyldodecylammonium) acetic acid bromide ([(CH2COOH)DMDA]Br) showed high catalytic activity and good reusability. This protocol was expanded to various epoxides, which gave the corresponding cyclic carbonates in good yields. The acidity of the catalyst influenced its catalytic activity.
N-n-Alkyl N,N-dimethylammonioacetic acid bromides: The first complete series of crystal and molecular structure determinations of an amphiphilic compound with alkyl chain lengths n = 1 ,..., 16
The molecular and crystal structures of 16 N-n-alkyl N,N-dimethylammonioacetic acid bromides with chain lengths between n = 1 and n = 16 have been determined. All compounds from n = 5 to n = 16 form bilayers with interdigitated chains. The even-numbered c