Growth of Calcite Single Crystals Underneath Monolayers of 5, 11, 17, 23‐Tetra‐t‐butyl‐25, 26, 27, 28‐tetrakis(carboxymethoxy)calix[4]arene

The amphiphilic 5, 11, 17, 23‐tetra‐t‐butyl‐25, 26, 27, 28‐tetrakis(carboxymethoxy)calix[4]arene (1) forms stable monolayers at the air‐water interface which serve as template to induce growth of CaCO3(calcite) single crystals. The nucleation density and the preferred orientation(s) of calcite single crystals depend on the surface pressure applied to the monolayer. Models of the pressure‐dependant aggregation of amphiphiles at the air‐water interface are derived from the crystal structures of the novel Ca coordination compounds [(Ca(C52H60O12))2Ca(H2O)2(CH3OH)3Ca(H2O)2(CH3OH)2]·12CH3OH·4H2O (2) and [Ca(C52H60O12)Ca(H2O)2.5(MeOH)0.5]·7H2O·CH3OH (3). Structural data are analyzed in terms of supramolecular packing arrangements and Ca coordination motifs of the constituting amphiphilic macrocycles.