Oriented crystallization of calcium carbonate under self-organized monolayers of amide-containing phospholipids

In the presence of calcium ions amide-containing phospholipid 1 self-assembles to form well-defined two-dimensional domains at the air-water interface. These domains act as templates for the crystallization of calcium carbonate that efficiently nucleate the growth of [10.0] oriented calcite irrespective of the surface concentration of the lipid. Responsible for this preference for nucleation at the (10.0) face is the formation of an intramolecular hydrogen bond between the phosphate group and the phenoxy moiety which forces the phosphate group to adopt a bidentate orientation toward the aqueous phase. It was shown that when this hydrogen bond was absent, that is, when the phosphate group is monomethylated, lateral pressure was required in order to enforce a similar conformation and accomplish the nucleation of [10.0] oriented calcite.