Fluorescent Indolo[2,3-b]quinoxalin-2-yl)(Phenyl)methanone Dyes: Photophysical, Aie Activity, Electrochemical, and Theoretical Studies

Herein, we have synthesized four indolo[2,3-b]quinoxalin-2-yl)(phenyl)methanone derivatives 1−4 by cyclocondensation. The photophysical studies of dyes in various solvents and neat solid film exhibit typical electronic spectra with inbuilt intramolecular charge transfer (ICT) (λmax: 397‒490 nm) confirming donor-acceptor architecture. Herein, dyes fluoresce in the blue-orange region (λEmax: 435–614) on excitation at their ICT maxima in toluene, ethyl acetate, chloroform, DMSO, and neat solid film. 1 and 2 which exhibit good emission intensity in all mediums, were studied for aggregation-induced emission (AIE) effect. Electrochemical studies indicate 1−4 possess relatively low lying LUMO (‒3.65 to ‒3.98 eV) comparable to reported n-type/electron-transporting materials. The HOMO and LUMO energy levels in 1−4 were evaluated by DFT and TD-DFT calculations. TGA analysis shows 1−4 exhibit good thermal stability. The characteristic optoelectronic properties and thermal stability signify these dyes are potential candidate for their application in optoelectronics.

In-Silico Molecular Docking and Pharmaco-Kinetic Activity Analysis of Potential Inhibitors against SARS-CoV-2 Spike Glycoproteins

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-COV-2) is a causative agent of the potentially fatal coronavirus disease (COVID-19). Coronavirus targets the human respiratory system primarily. It can also infect the gastrointestinal, hepatic, and central nervous systems of humans, avians, bats, livestock, mice, and many other wild animals, as these are primary targets of the pathogen. This study aims to screen out the most potent inhibitor for SARS-CoV-2 (COVID-19) spike glycoproteins among the selected drugs, and computational tools have been utilized for this purpose. The selected drugs have been designed to explore their structural properties in this study by molecular orbital calculation. To inhibit the spike glycoproteins, the performance of these drugs was also examined by molecular docking calculation. In improving the performance of drugs, non-bond interactions play a significant role. To determine the chemical reactivity of all the medicines, HOMO and LUMO energy values were also calculated. The combined calculations exhibited that Ledipasvir among the selected drugs can be the most potent drug to treat SARS-CoV-2 compared to other medications.

Theoretical study of the adsorption of BMSF-BENZ drug for osteoporosis disease treatment on Al-doped carbon nanotubes (Al-CNT) as a drug delivery vehicle

The adsorption energy of the BMSF-BENZ adsorbed complexes was investigated to understand the non-local dispersion interactions, with many other chemical parameters related to this subject like HOMO and LUMO, energy gap, and the time needed for the BMSF-BENZ to be desorbed from the nanotube (recovery time). Our study reveals that Al-CNT is a promising adsorbent for this drug as Eads of BMSF-BENZ/Al-CNT complexes are -22.09, -38.68, -12.89, -31.01, -27.31, -21.90, and -21.42 kcal/mol in the gas phase on the active atoms of the BMSF BENZ (Br, N8, N9, N58, O35, O41, and S), respectively. In addition, the spontaneous and favorable interaction between the BMSF BENZ and all nanoparticles was confirmed by investigating Gibbs free energy and quantum theory of atoms in molecule analysis (QTAIM) so that it can be used as an electrochemical sensor or biosensor. Furthermore, to more visualize the nature of intermolecular bonding and the strength of interaction between the BMSF-BENZ drug molecule and the nanotube, QTAIM has been widely studied in the case of drug delivery purposes. Al-CNT (4,0) can be extended as a drug delivery system and the work function type sensor.

4-(Trifluoromethoxy)phenyl-Containing Polymers as Promising Anodic Materials for Electrochromic Devices

Three 4-(trifluoromethoxy)phenyl-based polydithienylpyrroles (PTTPP, P(TTPP-co-DTC), and P(TTPP-co-DTP)) were synthesized electrochemically and their electrochromic behaviors were characterized. The introduction of electron withdrawing trifluoromethoxy unit in the side chain of polydithienylpyrroles (PSNS) decreases the HOMO and LUMO energy levels of PSNS. PTTPP film displays three various colors (grayish-yellow at 0 V, grayish-blue at 1.0 V, and bluish-violet at 1.4 V) from reduced to oxidized states. The optical contrast of PTTPP, P(TTPP-co-DTC), and P(TTPP-co-DTP) electrodes are 24.5% at 1050 nm, 49.0% at 916 nm, and 53.8% at 1302 nm, respectively. The highest η of the PTTPP electrode is 379.64 cm2 C−1 at 1050 nm. Three ECDs based on PTTPP, P(TTPP-co-DTC), or P(TTPP-co-DTP) as anodic film and PProDOT-Et2 as cathodic film were fabricated. PTTPP/PProDOT-Et2 ECD showed high transmittance change (35.7% at 588 nm) and high η (890.96 cm2·C−1 at 588 nm). P(TTPP-co-DTC)/PProDOT-Et2 and P(TTPP-co-DTP)/PProDOT-Et2 ECDs showed high transmittance change, rapid response time, adequate open circuit memory, and good electrochemical redox stability. Based on these findings, this work provides novel insights for appropriate design of high transmittance change and high efficient multi-colored electrochromic polymers.

Design, Synthesis, and Quantum Chemical Calculations of 2,6-Diphenylspiro[cyclohexane-1,3’-pyrido[1,2-a]pyrimidine]-2’,4,4’-trione through DFT approach

: Structural elucidation of synthesized 2,6-diphenylspiro[cyclohexane-1,3’-pyrido[1,2- a]pyrimidine]-2’,4,4’-trione has been done by UV, FT-IR, 1H, 13C NMR and mass spectroscopy. The molecule was further subjected to density functional theory (DFT) studies with B3LYP function using 6-31G(d,p) basis atomic set. The title molecule was investigated on the basis of thermodynamic properties, polarizability, hyperpolarizability, intermolecular interactions, HOMO and LUMO energy values, MESP, ESP and NBO computations to correlate experimental results with in-silico studies.

The Effect of Acceptor Structure on Emission Color Tuning in Organic Semiconductors with D–π–A–π–D Structures

A series of novel donor–acceptor D–π–A–π–D compounds were synthesized and characterized in order to determine the influence of different acceptor units on their properties. The introduction of acceptor moieties had a direct impact on the HOMO and LUMO energy levels. Fluorescence spectra of compounds can be changed by the choice of an appropriate acceptor and were shifted from the green to the near-infrared part of spectra. Due to observed concentration induced emission quenching, the green exciplex type host was used to evaluate the potential of synthesized molecules as emitters in organic light emitting diodes (OLEDs).

A Thiazolothiazole-Based Semiconducting Polymer with Well-Balanced Hole and Electron Mobilities

We report the synthesis and properties of a new thiazolothiazole (TzTz)-based semiconducting polymer incorporating the dithienothienothiophenebisimide (TBI) unit, named PTzTBI. PTzTBI showed relatively deep HOMO and LUMO energy levels of −5.48 and −3.20 eV, respectively. Although PTzTBI mainly formed face-on backbone orientation unfavorable for transistors, PTzTBI functioned as an ambipolar semiconductor for the first time with TzTz-based polymers, with reasonably high and well-balanced hole (0.02 cm2 V−1 s−1) and electron (0.01 cm2 V−1 s−1) mobilities.

Electronic Characters and Synthesis Method of Novel Conjugated System Based on Benzodithiophene Groups

Benzodithiophene based conjugated small molecules (SMBDTs) are usually used in organic photovoltaic (OPV), Organic Filed Effection Transistor (OFET), Organic Phototransistor (OPT) and Non-Linear Optical (NLO) chromophores. Band-gap engineering is one of the key design principles for π-conjugated materials and this can be done by altering the structures of SMBDTs with sidechain and backbone reactions. In this way, scientists develop several kinds of SMBDTs with different electron donors and acceptors. The alkoxyl and aromatic substituted BDT units are mostly used as the donors, while the alkyl cyanoacetate, dicyano, rhodamine, indenedione, thieno[3,4-c]pyrrole-4,6(5H)-dione, benzothiadiazole and diketopyrrolopyrrole groups are used as the acceptors. The electronic characters of SMBDTs including the HOMO and LUMO energy level are listed and discussed. The synthesis methods of SMBDTs are mostly in common, especially with the backbone reaction. There are about four coupling methods for the backbone reaction, mostly used is the Stille coupling methods. In this review paper, the common synthesis methods and the electronic characters by several samples are summarized to provide researchers an overview of SMBDTs’ synthesis, structures and applications.

Two novel blue phosphorescent host materials containing phenothiazine-5,5-dioxide structure derivatives

Two novel D–A bipolar blue phosphorescent host materials based on phenothiazine-5,5-dioxide: 3-(9H-carbazol-9-yl)-10-ethyl-10H-phenothiazine-5,5-dioxide (CEPDO) and 10-butyl-3-(9H-carbazol-9-yl)-10H-phenothiazine-5,5-dioxide (CBPDO) were synthesized and characterized. The photophysical, electrochemical and thermal properties were systematically investigated. CEPDO and CBPDO not only have a high triplet energy but also show a bipolar behavior. Moreover, their fluorescence emission peaks are in the blue fluorescence region at 408 nm and the fluorescence quantum efficiency (Φ) of CEPDO and CBPDO were 62.5% and 59.7%, respectively. Both CEPDO and CBPDO showed very high thermal stability with decomposition temperatures (T d) of 409 and 396 °C as well as suitable HOMO and LUMO energy levels. This preferable performance suggests that CEPDO and CBPDO are alternative bipolar host materials for the PhOLEDs.

Preparation, structure, and electrochemistry of porphyrinato titanium (IV) benzenedithiolates with a trithiole ring, a dithiin ring, and two 2-cyanoethylthio groups

The reaction of tetra([Formula: see text]-tolyl)porphyrinato titanium (IV) oxide (2) with 4,7-diethyl-5,6-dimercaptobenzo[1,2,3] trithiole (3a) produced the corresponding titanium (IV) complex, tetra([Formula: see text]-tolyl)porphyrinato titanium (IV) trithiolobenzenedithiolate (4a), fused with a trithiole ring. Related compounds 4b and 4c were prepared by a similar reaction of 2 with 5,8-diethyl-6,7-dimercaptobenzo[1,4]dithiin (3b) and 3,6-diethyl-4,5-dimercapto-1,2-bis(2-cyanoethylthio)benzene (3c). The structure of 4b was determined by X-ray crystallography. Compound 4c was further treated with cesium hydroxide to produce the corresponding dithiolate anion 4c2S, which was deposited on the gold electrode. The electrochemical property of the gold electrode was determined by cyclic voltammetry. The structure of simplified model compound 4b[Formula: see text] was optimized using the DFT method with the Gaussian 09 program. The optimized structure was utilized to calculate the NMR chemical shifts, the HOMO and LUMO energy levels, and the electronic transition in the absorption spectrum.