The development, characterization, and exploitation of novel materials based on the assembly of molecular components is an exceptionally active and rapidly expanding field. For this reason, the topic of molecule-based materials (MBMs) was chosen as the subject of a workshop sponsored by the Chemical Sciences Division of the United States Department of Energy. The purpose of the workshop was to review and discuss the diverse research trajectories in the field from a chemical perspective, and to focus on the critical elements that are likely to be essential for rapid progress. The MBMs discussed encompass a diverse set of compositions and structures, including clusters, supramolecular assemblies, and assemblies incorporating biomolecule-based components. A full range of potentially interesting materials properties, including electronic, magnetic, optical, structural, mechanical, and chemical characteristics were considered. Key themes of the workshop included synthesis of novel components, structural control, characterization of structure and properties, and the development of underlying principles and models. MBMs, defined as ªuseful substances prepared from molecules or molecular ions that maintain aspects of the parent molecular frameworkº are of special significance because of the capacity for diversity in composition, structure, and properties, both chemical and physical. Key attributes are the ability in MBMs to access the additional dimension of multiple length scales and available structural complexity via organic chemistry synthetic methodologies and the innovative assembly of such diverse components. The interaction among the assembled components can thus lead to unique behavior. A consequence of the complexity is the need for a multiplicity of both existing and new tools for materials synthesis, assembly, characterization, and theoretical analysis. For some technologically useful properties, e.g., ferro-or ferrimagnetism and superconductivity, the property is not a property of a molecule or ion; it is a cooperative solid-state (bulk) propertyÐa property of the entire solid. Hence, the desired properties are a consequence of the interactions between the molecules or ions, and understanding the solidstate structure as well as methods to predict, control, and modulate the structure are essential to understanding and manipulating such behaviors. As challenging as this is, molecules enable a substantially greater ability of control than atoms as building blocks for new materials and thus are well positioned to contribute significantly to new materials. The diversity of components and processes leads to the recognition of the critical role of cross-disciplinary research, including not only that between traditionally different areas within chemistry, but also between chemistry and biochemistry, physics, and a number of engineering disciplines. Enhancing communication and active collaboration between these groups was seen as a critical goal for the research area.

Treatment-related NEPC is an often under-recognized late manifestation of PCa with poor prognosis. Our study found that Gleason score was the only independent factor contributing to TTNEPC. Once NEPC is diagnosed, type of treatment and the number of organs with metastatic disease were the most important factors related to survival.

The construction of mixed monolayers containing hydrophobic and hydrophilic components for which the contact angles for three different liquids vary as a highly nonlinear function of the monolayer composition is reported. It is suggested that a prewetting, crystalline-like layer of water, possibly formed from bulk vapor, is present near the hydrophilic surface, because of an enhanced surface chemical potential ("surface field"). As the concentration of the hydrophilic component is lowered, increasing "quenched randomness" in the distribution of surface fields destroys the surface condensed water phase, thus triggering the observed nonlinearity in the contact angles. The microscopic structure of the water molecules adsorbed on an OH surface is revealed by continuum Monte Carlo simulations, with realistic force fields, and the scenario is supported by mean-field calculations on a simplified lattice-gas model. The observed wetting behavior at 30% relative humidity was altered for a relative humidity 52%, as well as when the surface of the monolayer was molecularly roughened by the addition of two CH2 groups to the hydrophobic (CH,-terminated) component of the mixed monolayers. It is suggested that this transitional phenomenon is due to a possible (true or rounded) surface phase transition, due to the formation of a prewetting water layer. This formation is triggered by variations in the quenched distribution of random surface fields. IntroductionWetting behavior of ordered and random surfaces has generated considerable interest recently,] in particular, the understanding of its relationship to the surface structure at the molecular level. Therefore, polymeric2 and monolayer surfaces, especially those of thiols on gold,) have been intensively investigated as model systems. Modern theories of wetting are based on phase diagrams representing competing ordering between bulk and surface

Organic 1D nanomaterials based on low-molecular-weight semiconducting organic compounds are of interest because they possess unique properties for use in electronic, optoelectronic, and photonic nanodevices.[1] Different organic materials and methods have been employed to synthesize 1D single-crystal nanostructures. [2] While there are reports on fabricating organic 1D single crystals on specific device platforms, [3] relatively few of these reports deal with aligned organic 1D nanostructures [4] because they are complex to pattern; [5] often requiring templates, an external electric field, or surface-invasive steps. Consequently, simple patterning and aligning methods of 1D crystals are highly desirable in the pursuit of low-cost, large-scale fabrication of parallel device arrays. Here, we report a one-step method that can enable the growth, alignment, and periodic patterning of organic 1D single-crystal nanowires on a solid substrate. This method combines the processes of solvent-evaporation-induced selfassembly, contact line pinning, and dewetting, thus promising to be a simple and versatile approach to prepare sophisticated nanostructures. [6,7] To demonstrate the efficiency of the method we choose a squaraine dye, 2,4-bis[4-(N,N-dimethylamino)phenyl]squaraine (SQ), as model organic semiconductor, because squaraines are a novel class of organic dyes for photonic applications such as imaging, nonlinear optics, photovoltaics, biological labeling, and photodynamic therapy.[8] Both ground and excited states of SQ are intramolecular donor-acceptor-donor charge-transfer (D-A-D CT) states and have been studied theoretically.[9] SQ molecules easily form aggregates in a ''slipped stack'' arrangement because of strong intermolecular interactions between the acceptor (A) and the donor (D) groups (Fig. S1 in the Supporting Information). [10] As it has been shown that strong donor-acceptor dipole-dipole intermolecular interactions can direct the growth of 1D nanostructures, [11] we expect SQ also to have a strong tendency to form 1D nanostructures under appropriate conditions. We report here the preparation of SQ nanostructures by solvent evaporation on a horizontal substrate. In a typical experiment, a drop of SQ/CH 2 Cl 2 solution (0.02 mM, about 10 mL) was placed on a silicon substrate at 20 8C. After complete evaporation of solvent, the substrate was examined by scanning electron microscopy (SEM). As shown in Figure 1a, many nanowires were deposited on the substrate. The majority of the nanowires had a length of about 40 mm and a diameter of 100-300 nm. The dimensions of the nanowires were found to be sensitive to the surface morphology of the substrate, temperature, and evaporation rate. However, under a saturated vapor environment, no nanowires formed on the substrate after solvent evaporation.The morphology of the nanowires was further characterized by transmission electron microscopy (TEM; Fig. 1b), which shows that the SQ nanostructures are solid wires of nanometer diameter. The nanowires are single-crystall...

Si nanowires (SiNWs) were covalently modified by fluorescence ligand, N-(quinoline-8-yl)-2-(3-triethoxysilyl-propylamino)-acetamide (QlOEt) and finally formed an optical sensor to realize a highly sensitive and selective detection for Cu(II). The QlOEt-modified SiNWs sensor has sensitivity for Cu(II) down to 10(-8) M, which is more sensitive than QlOEt alone. Metal ions interferences have no observable effect on the sensitivity and selectivity of QlOEt-modified SiNWs sensor. The SiNWs-based fluorescence sensor is reversible by addition of acid to replace Cu(II). The sensing mechanisms of QlOEt-modified SiNWs to Cu(II) and the rationale for the increase in sensitivity and selectivity of QlOEt-modified SiNWs over QlOEt on Cu(II) are discussed. The current sensor structure may be extendable to other chemo- and biosensors, and even to nanosensors for direct detection of specific materials in intracellular environment.

Large-scale arrays of highly oriented single-crystal ZnO nanotubes (ZNTs) are successfully fabricated on transparent conductive substrates by a simple method from an aqueous solution at a low temperature (typically 85°C). The tubular morphology of the ZnO nanostructures is formed by a defect-selective chemical etching of the electrodeposited ZnO nanorods. The size of the ZNT arrays is determined by that of ZnO nanorod arrays which can be readily controlled by tuning several electrodeposition parameters. The present method can be employed to prepare ZNT arrays on flexible, conductive substrates, as well as on patterned conductive substrates.

Many facets: A controlled synthesis results in high‐symmetry small‐molecular organic microcrystals with shapes that range from cubes through truncated cubes to rhombic dodecahedra (see picture). Morphological control was achieved by changes in solubility, which substantially alters the growth rate in the 〈100〉 direction relative to that in the 〈110〉 direction. Changes in morphology also lead to different optical properties of the crystals.

Concentric rings of organic nanowires (see schematic and micrographs) were prepared simply by controlling the evaporation of a droplet of dye solution in a confined space. By adjusting the initial concentration, the density and spacing of the concentric arrays of organic nanowires can be tuned. This facile approach can also be used to produce large‐scale organic semiconductor devices with nanowire configuration.