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Physics, 81(19), 195412-1-195412-11. [195412]. https://doi.org/10.1103/PhysRevB. 81.195412 Copyright Other than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons).Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons the number of authors shown on this cover page is limited to 10 maximum. Using a systematic method based on considering all possible hydrogen bond connections between molecules and subsequent density-functional theory ͑DFT͒ calculations, we investigated planar superstructures that the perylene-3,4,9,10-tetracarboxylic-3,4,9,10-dianhydride ͑PTCDA͒ molecules can form in one and two dimensions. Structures studied are mostly based on two molecule unit cells and all assemble in flat periodic arrays. We show that 42 different monolayer structures are possible, which can be split into eight families of distinct structures. A single representative of every family was selected and relaxed using DFT. We find square, herringbone and brick wall phases ͑among others͒ which were already observed on various substrates. Using scanning tunneling microscopy in ultrahigh vacuum, we also observed herringbone and square phases after sublimation of PTCDA molecules on the Au͑111͒ surface at room temperature, the square phase being observed for the first time on this substrate. The square phase appears as a thin stripe separating two herringbone domains and provides a perfect structural matching for them. A similar structural formation serving as a domain wall between two other phases has been recently reported on the same surface formed by melamine molecules ͓F. Silly et al., J. Phys. Chem. C 112, 11476 ͑2008͔͒. Our theoretical analysis helps to account for these and other observed complex structures.

a b s t r a c t a r t i c l e i n f o Available online xxxxIn 2013, 346 out of 616 fatal crashes in Louisiana were single vehicle crashes with Run-Off-Road (ROR) crashes being the most common type of single vehicle crash. In order to create effective countermeasures for reducing the number of fatal single vehicle ROR crashes, it is important to identify any associated key factors that can quantitatively assess the performance of roads, vehicles and humans. This research uses Multiple Correspondence Analysis (MCA), a multidimensional descriptive data analysis method that associates a combination of factors based on their relative distance in a two dimensional plane, to analyze eight years (2004-2011) of fatal ROR crashes in Louisiana. This method measures important contributing factors and their degree of association. The results revealed that drivers of lightweight trucks, drivers on undivided state highways, male drivers in passenger-vehicles at dawn, older female (65-74) drivers in non-passenger vehicles, older drivers facing hardship to yield in partial access control zones, and drivers with poor reaction time due to impaired driving were closely associated with fatal ROR crashes. Results of the MCA method can help researchers select the most effective crash countermeasures. Further work on the degree of association between the identified crash contributing factors can help safety management systems develop the most efficient crash reduction strategies.

A new heteroleptic polypyridyle Ru(II) complex was synthesized and deposited on surface by the diazonium electroreduction process. It yields to the covalent grafting of a monolayer. The functionalized surface was characterized by XPS, electrochemistry, AFM, and STM. A precise organization of the molecules within the monolayer is observed with parallel linear stripes separated by a distance of 3.8 nm corresponding to the lateral size of the molecule. Such organization suggests a strong cooperative process in the deposition process. This strategy is an original way to obtain well-controlled and stable functionalized surfaces for potential applications related to the photophysical properties of the grafted chromophore. As an exciting result, it is the first example of a self-organized monolayer (SOM) obtained using diazonium electroreduction.