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Self-assembled strategy has been proven to be a promising vista in constructing organized low-dimensional nanostructures with molecular precision and versatile functionalities on solid surfaces. Herein, we investigate by a combination of scanning tunneling microscopy (STM) and dispersion-corrected density functional theory (DFT), the adsorption of tetracene molecules on the silver substrate and the mechanism mediating the self-assembly on Ag(110). As expected, ordered domain is formed on Ag(110) after adsorption with adjacent molecules being imaged with alternating bright or dim pattern regularly. While such behavior has been assigned previously to the difference of molecular adsorption height, herein, it is possible to investigate essentially the mechanism leading to the periodic alternation of brightness and dimness for tetracene adsorbed on Ag(110) thanks to the consideration of Van der Waals (vdW) dispersion force. It is demonstrated that the adsorption height in fact is same for both bright and dim molecules, while the adsorption site and the corresponding interfacial charge transfer play an important role in the formation of such pattern. Our report reveals that vdW dispersion interaction is crucial to appropriately describe the adsorption of tetracene on the silver substrate, and the formation of delicate molecular architectures on metal surfaces might also offers a promising approach towards molecular electronics. [ABSTRACT FROM AUTHOR]

Abstract: The adsorption behavior of iron phthalocyanine (FePc) on the Cu(100) surface at the initial stage has been investigated by combining scanning tunneling microscopy (STM) and density functional theory (DFT) calculations. At low coverage, FePc molecules deposited on the sample surface at room temperature tend to adsorb dispersedly with their molecular planes parallel to the crystallographic directions of the substrate. Another interesting STM observation for the sub-monolayer coverage is that the molecular axes of FePc are aligned along [037] (as well as ) azimuth. At the monolayer coverage and elevated temperature, two types of ordered structures are observed. The FePc adsorption sites for the experimentally observed two distinct ordered domains have been revealed through DFT calculations. With further increasing the coverage, molecular clusters are formed particularly near the step edges. [Copyright &y& Elsevier]

Abstract: The ordered adsorption structures of FePc on Cu (100) have been studied by scanning tunneling microscopy (STM) and density functional theory (DFT) calculations. With the deposition rate beyond 0.5 ML per min, the FePc molecules are not deposited dispersedly but are deposited as molecular clusters. After the heat treatment (the temperature higher than 420K), the ordered organic structures of p(5×2) or p(2×5) are obtained. The ordered adsorption structures are in the tilt adsorption model. The FePc molecules in the different domains are aligned along the [011] or [] azimuth, respectively, the molecules are tilted. [Copyright &y& Elsevier]

Abstract: Using a combination of scanning tunneling microscopy (STM) and density functional theory calculations, we have studied the adsorption of tetracene on the Cu(110) (2×1)O substrate. At monolayer coverage the adsorbed molecules are in the flat-laying geometry with their long axis along the close-packed [001] direction of the substrate and a long-range ordered structure on the length scale up to 100nm has been observed. DFT calculation results indicate a stronger interaction between tetracene molecules and Cu(110) substrate than Cu(110) (2×1)O substrate. The preferential adsorption sites have also been pointed out on both substrates. The observed wavelike structure is explained by the interdigitation of C–H bonds of adjacent molecules. [Copyright &y& Elsevier]

Abstract: The monolayer structures of perylene adsorbed on Ag(110) surface were studied by combining scanning tunneling microscopy (STM) experiments and density functional theory (DFT) calculations. Several superstructures (i.e. loose and compact dimer structures, compact trimer structures) were observed. DFT calculation results show that the interaction between molecule and Ag substrate is weak, the intermolecular interaction is comparable with that between molecule and substrate. The organic self-assembly on metal surface results from the balance between intermolecular interaction and molecule–substrate interaction. On Ag(110) surface, the dimer-α structure was found to be more stable than other structures. [Copyright &y& Elsevier]