An ion beam source using electrospray ionization is presented for nondestructive vacuum deposition of mass‐selected large organic molecules and inorganic clusters. Electrospray ionization is used to create an ion beam from a solution containing the nanoparticles or molecules to be deposited. To form and guide the ion beam, radio frequency and electrostatic ion optics are utilized. The kinetic energy distribution of the particles is measured to control the beam formation and the landing process. The particle mass‐to‐charge ratio is analyzed by in situ time‐of‐flight mass spectrometry. To demonstrate the performance of the setup, deposition experiments with gold nanoclusters and bovine serum albumin proteins on graphite surfaces were performed and analyzed by ex situ atomic force microscopy. The small gold clusters are found to form three‐dimensional agglomerations at the surface, preferentially decorating the step edges. In contrast, bovine serum albumin creates two‐dimensional fractal nanostructures on the substrate terraces due to strong intermolecular interactions.

Metal-organic coordination networks (MOCNs) formed by coordination bonding between metallic centers and organic ligands can be efficiently engineered to exhibit specific magnetic, electronic, or catalytic properties [1]. Instead of depositing prefabricated MOCNs onto surfaces, it has been recently shown that two-dimensional (2D) MOCNs can be directly grown at metal surfaces under ultrahigh vacuum (UHV), thus creating highly regular 2D networks of metal atoms [2]. We show here [3] that this approach allows to predefine the geometry of the MOCN by using the substrate as a template to direct the formation of novel 1D metal-organic coordination chains (MOCCs).The templating role of substrates is well known in the field of surface epitaxial growth. Among the highly anisotropic substrates, the Cu(110) surface is one of the most commonly used. To demonstrate its strong 1D templating effect on organic molecules, a ligand with a triangular symmetry was selected, namely 1,3,5-benzenetri-carboxylic acid (trimesic acid, TMA). The three-fold rotation symmetry of TMA supports the formation of hexagonal 2D and 3D architectures, therefore strongly disfavoring the linear geometry.The deposition of TMA on Cu(110) under UHV at 300 K results in the formation of 1D chains along the <1bar10> direction, as observed by scanning tunneling microscopy (STM). This deposition temperature is high enough to provide mobile Cu adatoms through evaporation from kinks and steps onto the terraces. Analysis of similar systems by X-ray photoelectron spectroscopy showed that these adatoms catalyze the deprotonation of molecular carboxylate groups and are necessary for the formation of copper carboxylate complexes. The chains formed at 300 K typically show irregular kinks and poor long-range order. These inhomogeneities are removed by postannealing to 380-410 K to yield straight and highly periodic chains, referred to as MOCC-I hereafter.

Metal-organic coordination networks (MOCNs) formed by coordination bonding between metallic centers and organic ligands can be efficiently engineered to exhibit specific magnetic, electronic, or catalytic properties. [1][2][3][4][5][6] Instead of depositing prefabricated MOCNs onto surfaces, it has been recently shown that two dimensional (2D) MOCNs can be directly grown at metal surfaces in ultra high vacuum (UHV), thus creating highly regular 2D networks of metal atoms. [7][8][9][10][11][12] These grids have been pointed out to be potentially relevant for devices involving sensing, switching, and information storage. [13,14] We show here that this approach offers the additional advantage to predefine the MOCN geometry by using the substrate as template to direct the formation of novel 1D metal-organic coordination chains (MOCCs).The templating role of substrates is well known in the field of surface epitaxial growth. [15][16][17][18][19] Among the highly anisotropic substrates, the Cu(110) surface is one of the most common (Figure 1a and b). In order to evidence its strong 1D templating effect on organic molecules, a ligand with a triangular symmetry was selected: 1,3,5-benzenetricarboxylic acid (trimesic acid, TMA, Figure 1c). In fact, the 3-fold rotation symmetry supports the formation of hexagonal 2D and 3D architectures, [20][21][22] therefore strongly disfavoring the linear geometry. On the isotropic Cu(100) surface, TMA forms 0D carboxylate complexes and 2D networks. [9,10] The UHV deposition of TMA on Cu(110) at 300 K results in the formation of 1D chains along the 110 direction, as observed by STM. This deposition temperature is high enough to * * The authors wish to acknowledge Nian Lin, Magalí Lingenfelder, Alexander Schneider and Giacinto Scoles for fruitful discussions, HPC-EUROPA (project #506079) and INFM Progetto Calcolo Parallelo for computer resources.