Influence of point defects on Cu(100) surface on thermal stability of Fe–terephtalate metal–organic networks.

In this work, using the lattice model of terephthalic acid (TPA) and iron metal–organic networks on the Cu(100) surface, the effect of point defects of the metal surface on thermal stability of two representative structures have been estimated. The influence of both the fraction of defects and their type (positive or negative in terms of change of the binding energy) have been investigated. For the surfaces with high energetic heterogeneity, when the difference between the adsorption energies on a defect and adsorption site is comparable with the energy of coordination interactions in the system, ordered structures can be observed up to 2–10% of defects depending on their type. In this case the surface heterogeneity significantly affects the critical temperature of the phases. For the surface with low energetic heterogeneity, when the above-mentioned energy difference is comparable with the TPA–TPA lateral interactions, ordered structures exist up to 40–50% of defects. In this case, the surface heterogeneity does not significantly affect the critical temperature of the phases. When the fraction of defects is up to 10–20% and 10–40%, the self-assembly of the "cloverleaf" and "single-row" phases and its critical temperatures is not significantly affected. Since point defects are often presented on real surfaces, the results can be useful in creating adsorption layers consisting of TPA molecules and metal atoms on heterogeneous metal surfaces. [ABSTRACT FROM AUTHOR]