Molecular structure and modeling studies of azobenzene derivatives containing maleimide groups

Xue

2019

Sci Rep

Incorporating photochromic chromophores into polymer composites provides the possibility of a reversible photoswitch of the intrinsic properties of these materials. In this paper we report a route to attach azobenzene (AZO) moiety covalently to graphene oxide (GO) to create chromophore/graphene oxide (AZO-GO) hybrid, in which GO is both part of the chromophore and the template. Due to the high grafting density of AZO moiety and the low mass of the novel structure, the hybrid is a potential solar thermal storage material with high energy density of about 240 Wh·kg−1. It is found that C-H···π interaction between the cis-AZO chromophores and the aromatic rings of the substrate induces collective electronic modifications of GO at critical percentage of cis-isomers and reduce the thermal barrier of π-π* transition of the chromophores directly, which results in two sections of first-order reactions during the photoisomerization of trans- to cis-hybrid and also thermally stabilizes the cis-hybrid. Our findings demonstrate that high-performance AZO–GO hybrid can be manipulated by optimizing intermolecular nonbonding interactions.

Section: Discussionmentioning

confidence: 99%

A High Energy Density Azobenzene/Graphene Oxide Hybrid with Weak Nonbonding Interactions for Solar Thermal Storage

Xue

2019

Sci Rep

“…In addition, the electrostatic potential map helps us to understand the attraction and/or repulsion interactions between molecules. Consequently, charge density can explain the more preferable site for a nucleophilic attack …”

Section: Resultsmentioning

confidence: 99%

In Silico Studies of Mammalian δ‐ALAD Interactions with Selenides and Selenoxides

Nogara

Rocha

2017

Molecular Informatics

Previous studies have shown that the mammalian δ-aminolevulinic acid dehydratase (δ-ALAD) is inhibited by selenides and selenoxides, which can involve thiol oxidation. However, the precise molecular interaction of selenides and selenoxides with the active center of the enzyme is unknown. Here, we try to explain the interaction of selenides and the respective selenoxides with human δ-ALAD by in silico molecular docking. The in silico data indicated that Se atoms of selenoxides have higher electrophilic character than their respective selenides. Further, the presence of oxygen increased the interaction of selenoxides with the δ-ALAD active site by O…Zn coordination. The interaction of S atom from Cys124 with the Se atom indicated the importance of the nucleophilic attack of the enzyme thiolate to the organoselenium molecules. These observations help us to understand the interaction of target proteins with organoselenium compounds.

“…The bond length of C2−C3, C3−C4, C−N and N=N bonds in azobenzene are 1.402 Å, 1.417 Å, 1.433 Å and 1.290 Å respectively, which are in close agreement with the values reported in the literature. [34,35] The inclusion of linking agents (sulfur and nitrogen atoms) and Au atoms slightly alter the bond lengths. Note that the parallel bonds to the molecular axis (C2−C3, C5−C6 and C4−N7) are shortened and the other bonds are elongated.…”

Section: Structural Analysismentioning

confidence: 99%

A DFT Study on the Efficacy of Linking Agents (Sulfur and Nitrogen) to Connect Trans-azobenzene Sandwiched Between Two Gold Electrodes

Karthika¹,

Praveena²,

Ramachandran³

et al. 2020

Croat. Chem. Acta

Electronic structure calculations were performed to analyze the effectiveness of linking agents (sulfur and nitrogen) in connecting the trans-azobenzene sandwiched between two gold surfaces (Au-atoms). It was analyzed the dynamics of the load carrier and the electronic structure of the molecular backbone by applying an external electric field (EF), also a detailed structural, frontier orbital and natural bond orbital analysis (NBO) were performed. From the NBO analysis, it was possible to predict the path of charge flow in the molecular system. Electrostatic potential mapping allowed us to visualize the charge redistribution in the molecular system caused by the EF application. Our results indicate that when the nitrogen atom is used as a linking agent, the azo group of molecules may enhance their conductivity.