Recognition-improved monolayer formation on air-water interface

Molecular recognition mechanism was introduced into the monolayer formation of two barbituric derivatives, B1 and B2, on a series of melamine derivatives containing water sub-phase. The recognition pattern was found that each barbituric(or melamine) group forms 3-fold H-bonds on its two edges, respectively, with two of its neighboring melamine(barbituric) cores in the ratio of 1:1 on air-water interface. The area per molecule in this pattern is about 60-65 A2 for both Bl and B2. Such recognition improves the monolayer formation of Bl by increasing the collapse pressure around 20 mN/M and modulates the intermolecular distance of B2 in monolayer. These effects should be quite meaningful for both theoretical research and practical application of Langmuir-Blodgett films, especially.