TY  - JOUR
AB  - Structure formation of the highly polar molecule cytosine on the (111) cleavage plane of calcium fluoride is investigated in ultrahigh vacuum using noncontact atomic force microscopy at room temperature. Molecules form well-defined trimer structures, covering the surface as homogeneously distributed stable structures. Density-functional theory calculations yield a diffusion barrier of about 0.5 eV for individual molecules suggesting that they are mobile at room temperature. Furthermore, it is predicted that the molecules can form trimers in a configuration allowing all molecules to attain their optimum adsorption position on the substrate. As the trimer geometry facilitates hydrogen bonding between the molecules within the trimer, we conclude that the stabilization of individual diffusing molecules into stable trimers is due to a cooperative mechanism involving polar interactions between molecules and substrate as well as hydrogen bonding between molecules.
DA  - 2009
DO  - 10.1103/PhysRevB.80.205421
LA  - eng
IS  - 20
M2  - 205421
PY  - 2009
SN  - 1098-0121
SP  - 205421-
T2  - Physical Review B
TI  - Cooperative mechanism for anchoring highly polar molecules at an ionic surface
UR  - https://nbn-resolving.org/urn:nbn:de:0070-pub-29138370
Y2  - 2024-11-24T16:05:56
ER  -