scholarly journals 2,1,3-Benzothiadiazole Small Donor Molecules: A DFT Study, Synthesis, and Optoelectronic Properties

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1216 ◽  
Author(s):  
Dorota Zając ◽  
Damian Honisz ◽  
Mieczysław Łapkowski ◽  
Jadwiga Sołoducho
Keyword(s):  
Energy Gap ◽  
Suzuki Reaction ◽  
Theoretical Modeling ◽  
Dft Study ◽  
Yellow Light ◽  
Design And Synthesis ◽  
Near Ir ◽  
Wide Range ◽  
Ir Light ◽  
Semiconductor Properties

We herein report the design and synthesis of small-donor molecules, 2,1,3-benzothiadiazole derivatives (2a–d), by Stille or Suzuki reaction. The synthesized compounds were characterized by spectroscopic and electrochemical methods. The compounds 2a–d absorb the light in a wide range (the UV-green/yellow light (2c)) and emit from green to red/near IR light (2c). Furthermore, these compounds show a narrow energy gap (1.75–2.38 eV), and high Ea values increasing for polymers, which prove their electron-donating nature and semiconductor properties. The measurements were enhanced by theoretical modeling.

scholarly journals Design and synthesis of a new chromophore, 2-(4-nitrophenyl)benzofuran, for two-photon uncaging using near-IR light

2016 ◽  
Vol 52 (2) ◽  
pp. 331-334 ◽  
Author(s):  
Naomitsu Komori ◽  
Satish Jakkampudi ◽  
Ryusei Motoishi ◽  
Manabu Abe ◽  
Kenji Kamada ◽  
...  
Keyword(s):  
Design And Synthesis ◽  
Two Photon ◽  
Near Ir ◽  
Ir Light

A new chromophore, 2-(4-nitrophenyl)benzofuran (NPBF), was designed for two-photon (TP) uncaging using near-IR light.

scholarly journals Photo-redox activated drug delivery systems operating under two photon excitation in the near-IR

Nanoscale ◽  
2014 ◽  
Vol 6 (9) ◽  
pp. 4652-4658 ◽  
Author(s):  
Tania M. Guardado-Alvarez ◽  
Lekshmi Sudha Devi ◽  
Jean-Marie Vabre ◽  
Travis A. Pecorelli ◽  
Benjamin J. Schwartz ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Mesoporous Silica ◽  
Silica Nanoparticles ◽  
Drug Delivery Systems ◽  
Mesoporous Silica Nanoparticles ◽  
Design And Synthesis ◽  
Two Photon ◽  
Near Ir ◽  
Photon Excitation ◽  
Ir Light

We report the design and synthesis of a nano-container consisting of mesoporous silica nanoparticles with the pore openings covered by “snap-top” caps that are opened by near-IR light.

scholarly journals Insights into the Antioxidant Mechanism of Newly Synthesized Benzoxazinic Nitrones: In Vitro and In Silico Studies with DPPH Model Radical

Antioxidants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1224
Author(s):  
Stefania Marano ◽  
Cristina Minnelli ◽  
Lorenzo Ripani ◽  
Massimo Marcaccio ◽  
Emiliano Laudadio ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Epr Spectroscopy ◽  
Point Of View ◽  
Uv Spectrophotometry ◽  
Design And Synthesis ◽  
Antioxidant Mechanism ◽  
Primary Mechanism ◽  
In Silico Studies ◽  
Wide Range

Synthetic nitrone spin-traps are being explored as therapeutic agents for the treatment of a wide range of oxidative stress-related pathologies, including but not limited to stroke, cancer, cardiovascular, and neurodegenerative diseases. In this context, increasing efforts are currently being made to the design and synthesis of new nitrone-based compounds with enhanced efficacy. The most researched nitrones are surely the ones related to α-phenyl-tert-butylnitrone (PBN) and 5,5-dimethyl-1-pyrroline N-oxide (DMPO) derivatives, which have shown to possess potent biological activity in many experimental animal models. However, more recently, nitrones with a benzoxazinic structure (3-aryl-2H-benzo[1,4]oxazin-N-oxides) have been demonstrated to have superior antioxidant activity compared to PBN. In this study, two new benzoxazinic nitrones bearing an electron-withdrawing methoxycarbonyl group on the benzo moiety (in para and meta positions respect to the nitronyl function) were synthesized. Their in vitro antioxidant activity was evaluated by two cellular-based assays (inhibition of AAPH-induced human erythrocyte hemolysis and cell death in human retinal pigmented epithelium (ARPE-19) cells) and a chemical approach by means of the α,α-diphenyl-β-picrylhydrazyl (DPPH) scavenging assay, using both electron paramagnetic resonance (EPR) spectroscopy and UV spectrophotometry. A computational approach was also used to investigate their potential primary mechanism of antioxidant action, as well as to rationalize the effect of functionalization on the nitrones reactivity toward DPPH, chosen as model radical in this study. Further insights were also gathered by exploring the nitrone electrochemical properties via cyclic voltammetry and by studying their kinetic behavior by means of EPR spectroscopy. Results showed that the introduction of an electron-withdrawing group in the phenyl moiety in the para position significantly increased the antioxidant capacity of benzoxazinic nitrones both in cell and cell-free systems. From the mechanistic point of view, the calculated results closely matched the experimental findings, strongly suggesting that the H-atom transfer (HAT) is likely to be the primary mechanism in the DPPH quenching.

Lysosome Specific Platinum(II) Catecholates with Photoactive BODIPY for Imaging and Photodynamic Therapy in Near‐IR Light

2021 ◽  
Vol 2021 (9) ◽  
pp. 831-839
Author(s):  
Vanitha Ramu ◽  
Paramita Kundu ◽  
Aarti Upadhyay ◽  
Paturu Kondaiah ◽  
Akhil R. Chakravarty
Keyword(s):  
Photodynamic Therapy ◽  
Near Ir ◽  
Ir Light

scholarly journals The Highly Uniform Photoresponsivity from Visible to Near IR Light in Sb2Te3 Flakes

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1535
Author(s):  
Shiu-Ming Huang ◽  
Jai-Lung Hung ◽  
Mitch Chou ◽  
Chi-Yang Chen ◽  
Fang-Chen Liu ◽  
...  
Keyword(s):  
Band Structure ◽  
Energy Difference ◽  
Experimental Result ◽  
Light Illumination ◽  
Near Ir ◽  
State Band ◽  
Valence Bands ◽  
Low Dimensional ◽  
Low Dimensional Materials ◽  
Ir Light

Broadband photosensors have been widely studied in various kinds of materials. Experimental results have revealed strong wavelength-dependent photoresponses in all previous reports. This limits the potential application of broadband photosensors. Therefore, finding a wavelength-insensitive photosensor is imperative in this application. Photocurrent measurements were performed in Sb2Te3 flakes at various wavelengths ranging from visible to near IR light. The measured photocurrent change was insensitive to wavelengths from 300 to 1000 nm. The observed wavelength response deviation was lower than that in all previous reports. Our results show that the corresponding energies of these photocurrent peaks are consistent with the energy difference of the density of state peaks between conduction and valence bands. This suggests that the observed photocurrent originates from these band structure peak transitions under light illumination. Contrary to the most common explanation that observed broadband photocurrent carrier is mainly from the surface state in low-dimensional materials, our experimental result suggests that bulk state band structure is the main source of the observed photocurrent and dominates the broadband photocurrent.

scholarly journals A Perspective on the Application of Covalent Organic Frameworks for Detection and Water Treatment

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1651
Author(s):  
Cristina Arqueros ◽  
Félix Zamora ◽  
Carmen Montoro
Keyword(s):  
Water Treatment ◽  
Resource Scarcity ◽  
Covalent Organic Frameworks ◽  
Design Strategies ◽  
Free Standing ◽  
Water And Wastewater Treatment ◽  
Design And Synthesis ◽  
Water Detection ◽  
Wide Range ◽  
Quality Water

Global population growth and water resource scarcity are significant social problems currently being studied by many researchers focusing on finding new materials for water treatment. The aim is to obtain quality water suitable for drinking and industrial consumption. In this sense, an emergent class of crystalline porous materials known as Covalent-Organic Frameworks (COFs) offers a wide range of possibilities since their structures can be designed on demand for specific applications. Indeed, in the last decade, many efforts have been made for their use in water treatment. This perspective article aims to overview the state-of-the-art COFs collecting the most recent results in the field for water detection of pollutants and water treatment. After the introduction, where we overview the classical design strategies on COF design and synthesis for obtaining chemically stable COFs, we summarize the different experimental methodologies used for COFs processing in the form of supported and free-standing membranes and colloids. Finally, we describe the use of COFs in processes involving the detection of pollutants in water and wastewater treatment, such as the capture of organic compounds, heavy metals, and dyes, the degradation of organic pollutants, as well as in desalination processes. Finally, we provide a perspective on the field and the potential technological use of these novel materials.

scholarly journals The Band-Gap Studies of Short-Period CdO/MgO Superlattices

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Ewa Przeździecka ◽  
P. Strąk ◽  
A. Wierzbicka ◽  
A. Adhikari ◽  
A. Lysak ◽  
...  
Keyword(s):  
Band Gap ◽  
Layer Thickness ◽  
Energy Gap ◽  
Band Gaps ◽  
Short Period ◽  
Wide Range ◽  
Salt Structure ◽  
Short Period Superlattices ◽  
Direct Band ◽  
Sublayer Thickness

AbstractTrends in the behavior of band gaps in short-period superlattices (SLs) composed of CdO and MgO layers were analyzed experimentally and theoretically for several thicknesses of CdO sublayers. The optical properties of the SLs were investigated by means of transmittance measurements at room temperature in the wavelength range 200–700 nm. The direct band gap of {CdO/MgO} SLs were tuned from 2.6 to 6 eV by varying the thickness of CdO from 1 to 12 monolayers while maintaining the same MgO layer thickness of 4 monolayers. Obtained values of direct and indirect band gaps are higher than those theoretically calculated by an ab initio method, but follow the same trend. X-ray measurements confirmed the presence of a rock salt structure in the SLs. Two oriented structures (111 and 100) grown on c- and r-oriented sapphire substrates were obtained. The measured lattice parameters increase with CdO layer thickness, and the experimental data are in agreement with the calculated results. This new kind of SL structure may be suitable for use in visible, UV and deep UV optoelectronics, especially because the energy gap can be precisely controlled over a wide range by modulating the sublayer thickness in the superlattices.

scholarly journals Hybrid Waveguides: Guided Mid‐IR and Near‐IR Light within a Hybrid Hyperbolic‐Material/Silicon Waveguide Heterostructure (Adv. Mater. 11/2021)

2021 ◽  
Vol 33 (11) ◽  
pp. 2170079
Author(s):  
Mingze He ◽  
Sami I. Halimi ◽  
Thomas G. Folland ◽  
Sai S. Sunku ◽  
Song Liu ◽  
...  
Keyword(s):  
Silicon Waveguide ◽  
Near Ir ◽  
Ir Light

40 Years Trajectory of Amorphous Semiconductor Research

2000 ◽  
Vol 609 ◽  
Author(s):  
Yoshihiro Hamakawa
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Energy Gap ◽  
Early Period ◽  
Basic Research ◽  
Amorphous Semiconductor ◽  
Film Deposition ◽  
Terrestrial Environment ◽  
Heterojunction Solar Cells ◽  
Wide Range

ABSTRACTA review is given on a research trajectory of amorphous and microcrystalline semiconductors and their device applications proceeded since 1970. A brief explanation on the motivation to start amorphous semiconductor research is given to produce a new kind of synthetic semiconductor having continuous energy gap controllability with valency electron controllability through our experience of modulation spectroscopy in semiconductors.The first material we have challenged is Si-As-Te chalcogenide semiconductor which has a very wide vitreous region in Gibb's Triangle. A series of systematic experiments has been carried out in the terrestrial environment since 1971, and also within the TT-500A rocket experiment in 1980, and the Spacelab. J experiments FMPT (First Material Processing Test) project in 1992. The second material is hydrogenated amorphous silicon (a-Si:H) and its alloys started in 1976 just after the Garmisch Partenkirchen ICALS-6. With some basic research on the a-Si:H film deposition technology and film quality improvement, our continuous effort to improve the efficiency bore the tandem type solar cells in 1979, and also new products of a-SiC:H and a-SiGe:H in the early period of 1980s are described. These innovative device structures and materials have bloomed in the middle of 1980s in R & D phase such as a-SiC/a-Si heterojunction solar cells, a-Si/a-SiGe and also a-Si/poly-Si tandem type solar cells, and industrialized in recent few years. New kind of trials on full-color thin film light emitting devices has also been recently initiated with wide range of band gap controllability of a-SiC:H.The third material is microcrystalline silicon (µc-Si) and their alloys which gathers a tremendous R & D effort as a promised candidate for the bottom cell of the a-Si/µc-Si tandem solar cells aimed for the all-round plasma CVD process for the next age thin film photovoltaic devices. In the final part of presentation, a brief discussion will be given on a technological evolution from “bulk crystalline age” to “multilayered thin film age” in the semiconductor optoelectronics toward 21 century.

scholarly journals Defining the conditional basis of silicon phthalocyanine near-IR ligand exchange

2018 ◽  
Vol 20 (28) ◽  
pp. 19030-19036 ◽  
Author(s):  
Erin D. Anderson ◽  
Stacey Sova ◽  
Joseph Ivanic ◽  
Lisa Kelly ◽  
Martin J. Schnermann
Keyword(s):  
Ligand Exchange ◽  
Radical Anion ◽  
Near Ir ◽  
Silicon Phthalocyanines ◽  
Conditional Basis ◽  
Ir Light ◽  
Silicon Phthalocyanine

The near-IR light induced ligand exchange of silicon phthalocyanines involves a critical radical anion intermediate and is dependent on hypoxia and a reductant.

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