Temperature Dependence of Metal–Organic Heteroepitaxy

Ultrathin ionic liquid films on metal surfaces: adsorption, growth, stability and exchange phenomena

“…The general observation of the formation of a WL for all ILs on metal substrates studied so far (see Table 2) is attributed to a strongly stabilizing interaction of the metal surface (as deduced from higher desorption temperatures of the WL compared to multilayers, see Chapter 3.2), by formation of image dipoles within the metal and possible (partial) charge transfer [92,118]. This interpretation is in line with conventional molecular scale interpretations of growth behavior in metal-organic heteroepitaxy [137,138].…”

“…Simultaneously, the C alkyl signal of the [C 8 C 1 Im] + cation increases by more than 100%, while the porphyrin-related C 1s contribution decreases to 40%. This behavior indicates the exchange of the IL by the 2H-TPP molecules at the Ag (111) [83,182], which itself is likely stabilized laterally by strong phenyl-phenyl bonds [83,99,138,[183][184][185][186][187][188][189][190][191][192][193]. In fact, Thussing et al also reported in studies of organic bilayers a high thermal stability of the 2Dnetwork of the top layer molecules due to strong intermolecular bonding, limiting the mobility of the molecules at the metal surface below [161,164].…”

Surface chemistry of porphyrins and phthalocyanines

“…1.9. ) Temperature-and coverage-dependent STM studies of 2HTPP on Ag(1 1 1) showed that nucleation and growth at the 2HTPP/Ag interface followed the same principles as were established for metal heteroepitaxy [378]. Due to the hierarchy of energy barriers for diffusion of 2HTPP on the Ag(1 1 1) terraces and for diffusion along edges and around corners of 2HTPP islands, the shape of the organic aggregates was found to be strongly coverage dependent, with fractal shapes at low temperatures and compact shapes at higher temperature.…”

“…Due to the hierarchy of energy barriers for diffusion of 2HTPP on the Ag(1 1 1) terraces and for diffusion along edges and around corners of 2HTPP islands, the shape of the organic aggregates was found to be strongly coverage dependent, with fractal shapes at low temperatures and compact shapes at higher temperature. The energy barrier for terrace diffusion (2.9-5.8 kJ/mol) and the binding energy of a 2HTPP molecule to a 2HTPP island (12.5-15.4 kJ/mol) were estimated [378]. Within an island, the 2HTPP molecules on Ag(1 1 1) were found to form a lattice with a tetragonal unit cell.…”

Colloquium: Cluster growth on surfaces: Densities, size distributions, and morphologies

“…This "nucleation route" (Barth et al, 2000;Brune, 1998;Brune et al, 1994;Müller et al, 1996) to measuring surface diffusion coefficients and binding energies has been found particular useful. Examples are diffusion of Pd diffusion on SrTiO 3 (100) (Richter and Wagner, 2005), of Co diffusion on Cu(111) (Prieto et al, 2000), or of C 60 molecules on CaF 2 (111) (Loske et al, 2010), and of hydrogenated tetraphenyl porphyrin (2H-PPT) on Ag(111) (Rojas et al, 2011). A thorough overview on similar analyses of surface diffusion on metals can be found in Antczak and Ehrlich (2010).…”