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-dimethylammonioace tic acid bromides with chain lengths between n = 1 and n = 16 have been det ermined. All compounds from n = 5 to n = 16 form bilayers with interdigitat ed chains. The even-numbered chains display the chain packing type M-2(II). The chain packing of the odd-numbered chain compounds is less regular. The head groups of all compounds are connected via electrostatic N+ ... Br- in teractions, and by OH ... Br- hydrogen bonds. The compounds with short chai ns are packed in different ways. Their molecular conformation depends on th e crystal packing.