Molecular structures and hydrogen-bond networks in crystals of synthetic 1-D-galactosamide bolaamphiphiles

The crystal structures of synthetic 1-galactosamide bolaamphiphiles, N,N'-bis(beta-D-galactopyranosyl)decane-1, dicarboxamide (1) and N,N'-bis(B-D-galactopyranosyl)dodecane-1,12-dicarboxamide (2), were determined by single-crystal X-ray analysis. The space groups are P2(1), Z=2 With cell dimensions: a=13.624(2), b=4.832(3), c=21.178(3) Angstrom, beta=98.57(1)degrees for 1; a=13.521(2), b=4.838(1), c=23.706(2) Angstrom, beta=104.945(10)degrees for 2. The galactopyranosyl rings of 1 and 2 are in a C-4(l) chair conformation. The bolaamphiphile molecules are arranged in a layered structure for 1 and 2, with the alkylene chains packed parallel all over the layers. The hydroxyl groups of the galactopyranosyl rings in 1 and 2 form identical three-dimensional hydrogen-bond networks. The connecting decamethylene spacer of 1 has a kink conformation, while the dodecamethylene chain of 2 an all-trans zigzag conformation. (C) 2000 Elsevier Science Ltd. All rights reserved.