https://zenodo.org/record/1258869/files/article.pdf

NWChem: a comprehensive and scalable open-source solution for large scale molecular simulations

The semiconductor industry has seen a remarkable miniaturization trend, driven by many scientific and technological innovations. But if this trend is to continue, and provide ever faster and cheaper computers, the size of microelectronic circuit components will soon need to reach the scale of atoms or molecules—a goal that will require conceptually new device structures. The idea that a few molecules, or even a single molecule, could be embedded between electrodes and perform the basic functions of digital electronics—rectification, amplification and storage—was first put forward in the mid-1970s. The concept is now realized for individual components, but the economic fabrication of complete circuits at the molecular level remains challenging because of the difficulty of connecting molecules to one another. A possible solution to this problem is ‘mono-molecular’ electronics, in which a single molecule will integrate the elementary functions and interconnections required for computation.

Electronics using hybrid-molecular and mono-molecular devices

A summary of the technical advances that are incorporated in the fourth major release of the Q-Chem quantum chemistry program is provided, covering approximately the last seven years. These include developments in density functional theory methods and algorithms, nuclear magnetic resonance (NMR) property evaluation, coupled cluster and perturbation theories, methods for electronically excited and open-shell species, tools for treating extended environments, algorithms for walking on potential surfaces, analysis tools, energy and electron transfer modelling, parallel computing capabilities, and graphical user interfaces. In addition, a selection of example case studies that illustrate these capabilities is given. These include extensive benchmarks of the comparative accuracy of modern density functionals for bonded and non-bonded interactions, tests of attenuated second order Moller–Plesset (MP2) methods for intermolecular interactions, a variety of parallel performance benchmarks, and tests of the accuracy of implicit solvation models. Some specific chemical examples include calculations on the strongly correlated Cr_2 dimer, exploring zeolite-catalysed ethane dehydrogenation, energy decomposition analysis of a charged ter-molecular complex arising from glycerol photoionisation, and natural transition orbitals for a Frenkel exciton state in a nine-unit model of a self-assembling nanotube.

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Advances in molecular quantum chemistry contained in the Q-Chem 4 program package

Nanomaterials, such as metal or semiconductor nanoparticles and nanorods, exhibit similar dimensions to those of biomolecules, such as proteins (enzymes, antigens, antibodies) or DNA. The integration of nanoparticles, which exhibit unique electronic, photonic, and catalytic properties, with biomaterials, which display unique recognition, catalytic, and inhibition properties, yields novel hybrid nanobiomaterials of synergetic properties and functions. This review describes recent advances in the synthesis of biomolecule-nanoparticle/nanorod hybrid systems and the application of such assemblies in the generation of 2D and 3D ordered structures in solutions and on surfaces. Particular emphasis is directed to the use of biomolecule-nanoparticle (metallic or semiconductive) assemblies for bioanalytical applications and for the fabrication of bioelectronic devices.

Integrated Nanoparticle–Biomolecule Hybrid Systems: Synthesis, Properties, and Applications

The present invention is a method and apparatus relating to manufacturing nanostructure patterns and components using molecular science. The method includes overlaying a multilayer organic molecule resist on at least a portion of a parent structure selectively deposited on a substrate, depositing a layer over the parent structure and in contact with at least a portion of the multilayer organic resist, and removing the multilayer organic molecule resist to leave a residual structure.

/pdf/molecular-ruler-for-scaling-down-nanostructures-ctz7lc7kgp.pdf

Molecular ruler for scaling down nanostructures

Self-segregating hyperbranched polymer (HBP) additives have been utilized to concentrate silver nanoparticles (AgNPs) at the air interface of polyurethane films. The limited spontaneous surface migration of the AgNPs was enhanced through the addition of appropriately functionalized HBPs. Both amine and thiol terminated additives were employed to allow interaction of the HBP with the nanoparticles. Both types of additives increased surface concentration of silver modestly, though the thiol-terminated HBPs demonstrated nearly a seven-fold enhancement of surface migration. It was also found that wholly-aliphatic HBPs demonstrated only slightly reduced ability to bias AgNP concentration as compared to HBPs functionalized with perfluorinated chains. In addition, films containing 1% total silver concentration were tested for antimicrobial activity using the ASTM-E 2180 protocol. Significant reduction of the microorganisms was observed for all samples, 6-log reduction was achieved for the gram-negative bacteria P. aeruginosa, the gram-positive bacteria S. aureus, and the fungi C. albicans. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Self-segregating hyperbranched polymer/silver nanoparticle hybrids in thermoplastic polyurethane films†

We report the direct high-voltage poling of the chromophores 4-methoxy-4’-nitrostilbene (MNS) and 2-methyl-4-nitroaniline (MNA) in a 1.2 mm thick polymethylmethacrylate (PMMA) host. The DC fields used to pole the guest-host system varied in strength from 58 to 67 Vμm−1, and the presence of chromophore orientation in the poled samples was subsequently analyzed via Maker fringe analysis. We observed values of the SHG coefficient d33 of 0.7 to 1.75pm/V at 532nm.

Poling of visible chromophores in millimeter-thick PMMA host

Molecular-scale devices have recently become possible with self-assembly techniques Examples of a number of simple molecular devices and circuits include a negative-resistance device that exhibits peak-to-valley ratios exceeding 1000:1 and a molecular memory cell with refresh times exceeding 10 minutes

The design and measurement of molecular electronic switches and memories

2,5-di(phenylethynyl)-4′-4″-dithiolate-1-nitrobenzene has been shown to exhibit negative differential resistance (NDR) and spontaneous switching when inserted into inert molecular monolayers between metal contacts. We have used conducting atomic force microscopy to measure the electronic properties of individual dithiolated molecules 2,5-di(phenylethynyl)-4′-4″-dithiolate-1-nitrobenzene and 2,5-di(phenylethynyl)-4′4″-thioacetyl-benzene inserted into an alkanethiol monolayer and chemically bonded to gold nano-contacts to form a covalentlyconnected molecular circuit (bonded contacts). The data show qualitative agreement with previously published results for similar molecules deposited in a nanopore containing several hundred molecules, allowing us to make the important conclusion that the measured negative differential resistance (NDR) is native to the molecule and not an intermolecular phenomenon.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S1946427400130210

Organic molecules in an electrical circuit: An AFM study of a negative-differential-resistance molecule

We describe for the first time the fabrication and poling of a 700 μm thick bulk piece ofpolymethylmethacrylate (PMMA) doped with various concentrations of Disperse Red 1 (DR1). Maker fringe analysis demonstrates that poling fields of 57 V/μm to 71 V/μm induce substantial ordering of the DR1 chromophores, resulting in birefringence and significant d 33 and r 33 values. The poling of thick sections of guest-host polymers will have applications for a range of electro-optic applications, including modulators and terahertz generation and detection.

Adam M. Rawlett

Papers

Self-segregating hyperbranched polymer/silver nanoparticle hybrids in thermoplastic polyurethane films†

Poling of visible chromophores in millimeter-thick PMMA host

The design and measurement of molecular electronic switches and memories

Organic molecules in an electrical circuit: An AFM study of a negative-differential-resistance molecule

High-Voltage Poling of Bulk Guest-Host Polymers