Thus, a judicious choice of anchoring group and solvent used in the SAM formation process can result in a 10-fold improvement in the performance of molecular diodes. The diodes failed because of leakage currents flowing across defective parts in the SAM lowering the rectification ratios, while the yield in working junctions or the electronic structure of the SAMs was remarkably insensitive to defects inside the SAMs. As a result, the rectification ratio was reduced by more than a factor of 10 across a series of molecular diodes, containing a diphenylacetylene backbone and a ferrocenyl terminus. We even fixate on anchors when we know they are irrelevant to the discussion at hand. This paper shows that the performance of a large-area molecular diode depends on the choice of the anchoring group and solvent used for the formation of the self-assembled monolayer (SAM) in which both affect the surface coverage and the occurrence of disordered SAM domains. Anchoring, in Behavioral Finance terminology, refers to peoples tendency to rely too much on the initial piece of information offered (the 'anchor'). A well-known cognitive bias in negotiation and in other contexts, the anchoring bias describes the common tendency to give too much weight to the first number put forth in a discussion and then inadequately adjust from that starting point, or the anchor. Although it is commonly accepted that the performance and electrical characteristics of molecular tunneling junctions depend strongly on the supramolecular structure of the molecules inside the junctions, how sensitive molecular junctions are to small supramolecular changes and the factors that cause disorder are poorly understood for most types of molecular junctions. 19759-19767 ISSN: 1932-7455 Subject: diodes, electrical properties, physical chemistry, solvents Abstract: The failure modes of molecular junctions have been only sporadically investigated, but they are important to understand so they can be prevented and molecular junctions can be optimized. Nijhuis Source: Journal of physical chemistry 2019 v.123 no.32 pp. Regarding the preparation of photonic antenna systems, a stopcock with a cationic tail was found to be the most convenient solution.Unraveling the Failure Modes of Molecular Diodes: The Importance of the Monolayer Formation Protocol and Anchoring Group to Minimize Leakage Currents Author: Lejia Wang, Li Yuan, Li Jiang, Xiaojiang Yu, Liang Cao, Christian A. Stopcocks were designed to enable adsorption by means of van der Waals or electrostatic interactions, as well as by covalent binding. Heads and tails: The synthesis of stopcocks based on zinc phthalocyanine complexes for selective adsorption at the channel entrances of zeolite L is reported (see figure). Regarding the design of photonic antenna systems, a stopcock with a cationic tail was found to be the most convenient, based on the observation that efficient energy transfer from molecules located in the zeolite nanochannels is more readily obtained than in the other cases. Stopcocks that rely on van‐der‐Waals‐driven adsorption require careful selection of the solvent used for the deposition onto the zeolite surface to avoid a nonspecific distribution of the molecules. The introduction of either an inert SiMe 3 moiety, an imidazolium cation or a reactive isothiocyanate (NCS) group allows attachment to the channel entrances of zeolite L through van der Waals interactions, electrostatic interactions, or covalent binding, respectively. The synthesis of stopcocks based on zinc phthalocyanine for selective adsorption at the channel entrances of zeolite L is reported.
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