Oriented crystallization of calcite single crystals grown underneath monolayers of tetracarboxyresorc[4]arenes

Abstract

The crystal structures of rccc-5,11,17,23-tetracarboxy-4,6,10,12,16,18,22,24-octa-O-methyl-2,8,14,20-tetra(n-undecyl)resorc[4]arene, 1, and its Ca salt, 2, are described. Structural data were analyzed in terms of supramolecular packing motifs of the constituent amphiphilic macrocycles. Monolayer experiments indicate that a similar packing arrangement can be predicted for monolayers of 1 spread at the air–water interface. CaCO₃ (calcite) single crystals were grown underneath monolayers of 1 with highly uniform (012) orientation. This particular orientation was observed for a variety of structurally dissimilar monolayers indicating that macroscopic film properties such as average charge density or mean dipole moment have a decisive influence on templated calcite growth.