Structurally-modified subphthalocyanines: molecular design towards realization of expected properties from the electronic structure and structural features of subphthalocyanine

2014 ◽  
Vol 50 (53) ◽  
pp. 6949-6966 ◽  
Author(s):  
Soji Shimizu ◽  
Nagao Kobayashi
Keyword(s):  
Electronic Structure ◽  
Molecular Design ◽  
Structural Features ◽  
Feature Article ◽  
System 2

This feature article summarizes recent contributions of the authors in the synthesis of structurally-modified subphthalocyanines, which covers (1) modification of the conjugated system, (2) core-modification, and (3) exterior-modification.

scholarly journals Structural Features That Stabilize ZnO Clusters: An Electronic Structure Approach

Computation ◽  
2013 ◽  
Vol 1 (1) ◽  
pp. 16-26 ◽  
Author(s):  
Csaba Szakacs ◽  
Erika Merschrod S. ◽  
Kristin Poduska
Keyword(s):  
Electronic Structure ◽  
Structural Features ◽  
Structure Approach ◽  
Zno Clusters

scholarly journals Deep Learning-Based Self-Driving Car: JetBot with NVIDIA AI Board to Deliver Items at Agricultural Workplace with Object-Finding and Avoidance Functions

2020 ◽  
Vol 2 (3) ◽  
Author(s):  
Shinji Kawakura ◽  
Ryosuke Shibasaki
Keyword(s):  
Deep Learning ◽  
Structural Features ◽  
Error Rates ◽  
Stress Disorders ◽  
The Novel ◽  
Pet Bottles ◽  
System 2 ◽  
Heat Stress Disorders ◽  
Experimental Trials ◽  
Working Situation

In this study, we attempt to develop a deep learning-based self-driving car system to deliver items (e.g., harvested onions, agri-tools, PET bottles) to agricultural (agri-) workers at an agri-workplace. The system is based around a car-shaped robot, JetBot, with an NVIDIA artificial intelligence (AI) oriented board. JetBot can find diverse objects and avoid them. We implemented experimental trials at a real warehouse where various items (glove, boot, sickle (falx), scissors, and hoe), called obstacles, were scattered. The assumed agri-worker was a man suspending dried onions on a beam. Specifically, we developed a system focusing on the function of precisely detecting obstacles with deep learning-based techniques (techs), self-avoidance, and automatic delivery of small items for manual agri-workers and managers. Both the car-shaped figure and the deep learning-based obstacles-avoidance function differ from existing mobile agri-machine techs and products with respect to their main aims and structural features. Their advantages are their low costs in comparison with past similar mechanical systems found in the literature and similar commercial goods. The robot is extremely agile and easily identifies and learns obstacles. Additionally, the JetBot kit is a minimal product and includes a feature allowing users to arbitrarily expand and change functions and mechanical settings. This study consists of six phases: (1) designing and confirming the validity of the entire system, (2) constructing and tuning various minor system settings (e.g., programs and JetBot specifications), (3) accumulating obstacle picture data, (4) executing deep learning, (5) conducting experiments in an indoor warehouse to simulate a real agri-working situation, and (6) assessing and discussing the trial data quantitatively (presenting the success and error rates of the trials) and qualitatively. We consider that from the limited trials, the system can be judged as valid to some extent in certain situations. However, we were unable to perform more broad or generalizable experiments (e.g., execution at mud farmlands and running JetBot on non-flat floor). We present experimental ranges for the success ratio of these trials, particularly noting crashed obstacle types and other error types. We were also able to observe features of the system’s practical operations. The novel achievements of this study lie in the fusion of recent deep learning-based agricultural informatics. In the future, agri-workers and their managers could use the proposed system in real agri-places as a common automatic delivering system. Furthermore, we believe, by combining this application with other existing systems, future agri-fields and other workplaces could become more comfortable and secure (e.g., delivering water bottles could avoid heat (stress) disorders).

General Screening of Surface Alloys for Catalysis

2020 ◽  
Author(s):  
Matthew Montemore ◽  
Chukwudi F. Nwaokorie ◽  
Gbolade O. Kayode
Keyword(s):  
Electronic Structure ◽  
Catalytic Performance ◽  
Structural Features ◽  
Design Parameters ◽  
Surface Alloys ◽  
Catalytic Surfaces ◽  
Challenges And Opportunities ◽  
Adsorption Energies ◽  
Using Data ◽  
Structure Properties

Intensive research in catalysis has resulted in design parameters for many important catalytic reactions; however, designing new catalysts remains difficult, partly due to the time and expense needed to screen a large number of potential catalytic surfaces. Here, we create a general, efficient model that can be used to screen surface alloys for many reactions without any quantum-based calculations. This model allows the prediction of the adsorption energies of a variety of species (explicitly shown for C, N, O, OH, H, S, K, F) on metal alloy surfaces that include combinations of nearly all of the d-block metals. We find that a few simple structural features, chosen using data-driven techniques and physical understanding, can be used to predict electronic structure properties. These electronic structure properties are then used to predict adsorption energies, which are in turn used to predict catalytic performance. This framework is interpretable and gives insight into how underlying structural features affect adsorption and catalytic performance. We apply the model to screen more than 10<sup>7</sup> unique surface sites on approximately 10<sup>6</sup> unique surfaces for 7 important reactions. We identify novel surfaces with high predicted catalytic performance, and demonstrate challenges and opportunities in catalyst development using surface alloys. This work shows the utility of a general, reusable model that can be applied in new contexts without requiring new data to be generated.<br>

Protonation of 4 H-Pyran-4-one and its Sulfur Analogues. MNDO Study

1984 ◽  
Vol 39 (3) ◽  
pp. 267-275 ◽  
Author(s):  
Mirjana Eckert-Maksić
Keyword(s):  
Electronic Structure ◽  
Experimental Evidence ◽  
Electron Density ◽  
Structural Features ◽  
Electron Drift ◽  
Strong Polarization ◽  
Appreciable Increase ◽  
Cyclic Conjugation ◽  
Molecular And Electronic Structure ◽  
Good Agreement

AbstractThe molecular and electronic structure of 4H-pyran-4-one and its mono- and disubstituted sulfur analogues (1-4) are studied by the MNDO method. The salient structural features are qualitatively reproduced and the trend of changes of geometric parameters is in good agreement with experiment. The charge distributions exhibit strong polarization due to the large π-electron drift toward the exo-heteroatom. The protonated conjugated acids are considered too. It is found that exo-heteroatom protonation is favoured by 60-80 kcal/mol over the attachment of the proton to the intraring heteroatom. This is in accordance with experimental evidence. It is rationalized by the higher electron density centered on the exo-heteroatom and the appreciable increase in aromatic cyclic conjugation taking place upon the exo-protonation.

scholarly journals Novel Protease Inhibitors (PIs) Containing Macrocyclic Components and 3(R),3a(S),6a(R)-bis-Tetrahydrofuranylurethane That Are Potent against Multi-PI-Resistant HIV-1 Variants In Vitro

2010 ◽  
Vol 54 (8) ◽  
pp. 3460-3470 ◽  
Author(s):  
Yasushi Tojo ◽  
Yasuhiro Koh ◽  
Masayuki Amano ◽  
Manabu Aoki ◽  
Debananda Das ◽  
...  
Keyword(s):  
Protease Inhibitors ◽  
Molecular Design ◽  
Antiviral Agent ◽  
Structural Features ◽  
Biological Properties ◽  
Van Der Waals Interactions ◽  
Protein Ligand Interactions ◽  
Ligand Interactions ◽  
Hiv 1

ABSTRACT Natural products with macrocyclic structural features often display intriguing biological properties. Molecular design incorporating macrocycles may lead to molecules with unique protein-ligand interactions. We generated novel human immunodeficiency virus type 1 (HIV-1) protease inhibitors (PIs) containing a macrocycle and bis-tetrahydrofuranylurethane. Four such compounds exerted potent activity against HIV-1LAI and had 50% effective concentrations (EC50s) of as low as 0.002 μM with minimal cytotoxicity. GRL-216 and GRL-286 blocked the replication of HIV-1NL4-3 variants selected by up to 5 μM saquinavir, ritonavir, nelfinavir, lopinavir, or atazanavir; they had EC50s of 0.020 to 0.046 μM and potent activities against six multi-PI-resistant clinical HIV-1 (HIVmPIr ) variants with EC50s of 0.027 to 0.089 μM. GRL-216 and -286 also blocked HIV-1 protease dimerization as efficiently as darunavir. When HIV-1NL4-3 was selected by GRL-216, it replicated progressively more poorly and failed to replicate in the presence of >0.26 μM GRL-216, suggesting that the emergence of GRL-216-resistant HIV-1 variants is substantially delayed. At passage 50 with GRL-216 (the HIV isolate selected with GRL-216 at up to 0.16 μM [HIV216-0.16 μM]), HIV-1NL4-3 containing the L10I, L24I, M46L, V82I, and I84V mutations remained relatively sensitive to PIs, including darunavir, with the EC50s being 3- to 8-fold-greater than the EC50 of each drug for HIV-1NL4-3. Interestingly, HIV216-0.16 μM had 10-fold increased sensitivity to tipranavir. Analysis of the protein-ligand X-ray structures of GRL-216 revealed that the macrocycle occupied a greater volume of the binding cavity of protease and formed greater van der Waals interactions with V82 and I84 than darunavir. The present data warrant the further development of GRL-216 as a potential antiviral agent for treating individuals harboring wild-type and/or HIVmPIr .

Electronic structure and molecular design of simplified polyimide systems

1992 ◽  
Vol 1 (4) ◽  
Author(s):  
Keizo Nakajima ◽  
Kazuyoshi Tanaka ◽  
Tokio Yamabe
Keyword(s):  
Electronic Structure ◽  
Molecular Design

scholarly journals A radical mixed-ligand gold bis(dithiolene) complex

2021 ◽  
Vol 57 (13) ◽  
pp. 1615-1618
Author(s):  
Romain Perochon ◽  
Frédéric Barrière ◽  
Olivier Jeannin ◽  
Lidia Piekara-Sady ◽  
Marc Fourmigué
Keyword(s):  
Electronic Structure ◽  
Structural Features ◽  
Mixed Ligand

Asymmetry in the electronic structure of a mixed-ligand gold bis(dithiolene) complex explains its peculiar optical, electrochemical and structural features.

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