Rigid and planar π-conjugated molecules leading to long-lived intramolecular charge-transfer states exhibiting thermally activated delayed fluorescence.

Intramolecular charge transfer (ICT) occurs when photoexcitation causes electron transfer from an electron donor to an electron acceptor within the same molecule and is usually stabilized by decoupling of the donor and acceptor through an orthogonal twist between them. Thermally activated delayed fluorescence (TADF) exploits such twisted ICT states to harvest triplet excitons in OLEDs. However, the highly twisted conformation of TADF molecules results in limited device lifetimes.

Synthesis and structural study of the partially disordered complex hexagonal phase δ-MnZn.

A detailed structural analysis of the Zn-rich δ-MnZn phase using single-crystal X-ray diffraction is presented. The δ phase has been synthesized by the high-temperature synthetic route. The structure crystallizes in space group P6/mmc (Pearson symbol hP556) with unit-cell parameters: a = b = 12.

Exciplex, Not Heavy-Atom Effect, Controls the Triplet Dynamics of a Series of Sulfur-Containing Thermally Activated Delayed Fluorescence Molecules.

The efficiency of thermally activated delayed fluorescence (TADF) in organic materials relies on rapid intersystem crossing rates and fast conversion of triplet (T) excitons into a singlet (S) state. Heavy atoms such as sulfur or selenium are now frequently incorporated into TADF molecular structures to enhance these properties by increased spin-orbit coupling [spin orbit coupling (SOC)] between the T and S states. Here a series of donor-acceptor (D-A) molecules based on 12-benzo[4,5]thieno[2,3-]carbazole and dicyanopyridine is compared with their nonsulfur control molecules designed to probe such SOC effects.

Understanding of magnetic behavior of the pseudo-binary CoNiZn: in the light of crystal and electronic structures.

A high-temperature synthetic approach is used to prepare a series of pseudo-binary phases-CoNiZn. In the structures of CoNiZn, the statistical distribution between Co and Ni that is suggested by compositional analysis is confirmed by combined refinements of X-ray and neutron powder diffraction (NPD) experimental data. The aforementioned phases adopt a body-centered cubic lattice with a noncentrosymmetric space group 4̄3 (217).

Supramolecular J- and H-Aggregation of Naphthalimide-Conjugated Dipeptide in Mixed-Solvent Systems and its Application in Cell Imaging.

In this work, a core-substituted NMI-conjugated dipeptide (4MNLV) was extensively studied in mixed solvent systems to explore the polarity effect on the self-assembly pattern and their photophysical property. 4MNLV adopted J- or H- type aggregation pattern depending upon the polarity index of the solvent system chosen. The self-assembly process was achieved through the anti-solvent effect.

Surfactant-modified coconut coir powder (SMCCP) as a low-cost adsorbent for the treatment of dye-contaminated wastewater: parameters and adsorption mechanism.

The dye-contaminated wastewater discharged from various industries such as dye manufacturing, paint, textile, paper, and cosmetic is a prime source of surface water pollution having serious detrimental effects on both the environment and human beings. These hazardous dyes when exposed to water obstruct the penetration of sunlight into the water and thus restrain aquatic plants from generating photosynthetic compounds. Moreover, some dyes are potential cancer-causing and also negatively impact the human nervous and respiratory systems.

Double Helix of Icosahedra Structure and Spin Glass Magnetism of the δ-CoZnMn ( = 0.4-3.5) Pseudo-Binary Alloys.

We have synthesized δ-CoZnMn ( = 0.4-3.5) pseudo-binary alloys of 10 different compositions by a high-temperature solid-state synthetic route, determined their crystal structures and the Mn substitution pattern, and estimated the existence range of the δ-phase.

Gd Encapsulation on 2D-g-CN Nanostructure for Spintronics and Ultrasound Assisted Photocatalytic Applications: First-Principles and Experimental Studies.

Atomically thin two-dimensional (2D) semiconductors have high potential in optoelectronics and magneto-optics appliances due to their tunable band structures and physicochemical stability. The work demonstrates that Gd incorporated 2D-g-CN nanosheet (Gd/2D-g-CN NS) is synthesized through chemisorption methodology for defect enrichment. The material characterizations reveal that the ion decoration enhances the surface area and defect concentration of the 2D sheet.

Understanding the effects of oxytocin receptor variants on OXT-OXT receptor binding: A mathematical model.

Approximately half of U.S. women giving birth annually receive Pitocin, the synthetic form of oxytocin (OXT), yet its effective dose can vary significantly.

Exploring the Early Time Behavior of the Excited States of an Archetype Thermally Activated Delayed Fluorescence Molecule.

Optical pump-probe techniques allow for an in-depth study of dark excited states. Here, we utilize them to map and gain insights into the excited states involved in the thermally activated delayed fluorescence (TADF) mechanism of a benchmark TADF emitter . The results identify different electronic excited states involved in the key TADF transitions and their nature by combining pump-probe and photoluminescence measurements.

Phenylalanine-based fibrillar systems.

Phenylketonuria (PKU) is an inborn metabolic disorder characterized by excess accumulation of phenylalanine (Phe) and its fibril formation, resulting in progressive intellectual disability. Several research groups have approached from various directions to understand the formation of toxic amyloid fibrils from the essential amino acid Phe. Different parameters like the nature of the solvent, pH, Phe concentration, temperature, influence the fibril formation kinetics.

Intramolecular locking and coumarin insertion: a stepwise approach for TADF design.

Three novel TADF (thermally activated delayed fluorescence) emitters based on the well-studied Qx-Ph-DMAC fluorophore are designed and synthesized. The photophysical properties of these materials are studied from a theoretical and experimental point of view, demonstrating the cumulative effects of multiple small modifications that combine to afford significantly improved TADF performance. First, an extra phenyl ring is added to the acceptor part of Qx-Ph-DMAC to increase the conjugation length, resulting in BQx-Ph-DMAC, which acts as an intermediate molecular structure.

Azaborine as a Versatile Weak Donor for Thermally Activated Delayed Fluorescence.

Extensive research has been devoted to the development of thermally activated delayed fluorescence emitters, especially those showing pure-blue emission for use in lighting and full-color display applications. Toward that goal, herein we report a novel weak donor, 1,4-azaborine (AZB), with complementary electronic and structural properties compared to the widely used dimethylacridan (DMAC) or carbazole (Cz) donors. Coupled with a triazine acceptor, is the direct structural analogue of the high-performance and well-studied green TADF emitter and has Δ = 0.

Dimensionality effects of g-CN from wettability to solar light assisted self-cleaning and electrocatalytic oxygen evolution reaction.

Unique interfacial properties of 2D materials make them more functional than their bulk counterparts in a catalytic application. In the present study, bulk and 2D graphitic carbon nitride nanosheet (bulk g-CN and 2D-g-CN NS) coated cotton fabrics and nickel foam electrode interfaces have been applied for solar light-driven self-cleaning of methyl orange (MO) dye and electrocatalytic oxygen evolution reaction (OER), respectively. Compared to bulk, 2D-g-CN coated interfaces show higher surface roughness (1.

Probing Molecular Chirality on the Self-Assembly and Gelation of Naphthalimide-Conjugated Dipeptides.

In this work, 1,8-naphthalimide (NMI)-conjugated three hybrid dipeptides constituted of a β-amino acid and an α-amino acid have been designed, synthesized, and purified. Here, in the design, the chirality of the α-amino acid was varied to study the effect of molecular chirality on the supramolecular assembly. Self-assembly and gelation of three NMI conjugates were studied in mixed solvent systems [water and dimethyl sulphoxide (DMSO)].

Balanced Energy Gaps as a Key Design Rule for Solution-Phase Organic Room Temperature Phosphorescence.

Metal-free organic emitters that display solution-phase room temperature phosphorescence (sRTP) remain exceedingly rare. Here, we investigate the structural and photophysical properties that support sRTP by comparing a recently reported sRTP compound (BTaz-Th-PXZ) to two novel analogous materials, replacing the donor group by either acridine or phenothiazine. The emissive triplet excited state remains fixed in all three cases, while the emissive charge-transfer singlet states (and the calculated paired charge-transfer T state) vary with the donor unit.

A facile and green synthesis of Mn and P functionalized graphitic carbon nitride nanosheets for spintronics devices and enhanced photocatalytic performance under visible-light.

Manganese and phosphorus co-doped, graphitic carbon nitride (g-CN) nanosheet (Mn/P-g-CN) is prepared by facile and green calcination process of melamine (CHN), manganese chloride tetrahydrate (MnCl·4HO), and ammonium dihydrogen phosphate ((NH)HPO). The Mn/P co-doping significantly enhances magnetic values compared to pristine-g-CN, phosphorus-doped g-CN (P-g-CN), and manganese-doped g-CN (Mn-g-CN). We find that Mn/P-g-CN is a half-metallic ferromagnetic material having a magnetic moment and Curie temperature of 4.

NiInSb: Synthesis, Crystal Structure, Electronic Structure, and Magnetic Properties.

The ternary phase with the composition NiInSb has been synthesized by high-temperature synthesis and structurally characterized by a combination of X-ray analysis, neutron diffraction analysis, and theoretical calculations. The structure of NiInSb crystallizes in the orthorhombic space group with lattice constants = 7.111(3) Å, = 5.

Room Temperature Phosphorescence in Solution from Thiophene-Bridged Triply Donor-Substituted Tristriazolotriazines.

Most organic room-temperature phosphorescence (RTP) emitters do not show their RTP in solution. Here, we incorporated sulfur-containing thiophene bridges between the donor and acceptor moieties in D A-type tristriazolotriazines (TTTs). The thiophene inclusion increased the spin-orbit coupling associated with the radiative T →S pathway, allowing RTP to be observed in solution for all compounds, likely assisted by protection of the emissive TTT-thiophene core from the environment by the bulky peripheral donors.

Manganese substitution induced magnetic transformation and magnetoelectricity in SrFeO.

In this study, manganese substituted strontium hexaferrite (SrFeMnO; = 0, 3, 5, and 7) prepared by the sol-gel auto-combustion method are studied. We observed that the substituted Mn preferentially goes to the 2a and 12k sites of Fe. Raman modes related to the 12k site suggest the stiffening of the lattice.

Tuning of the Supramolecular Helicity of Peptide-Based Gel Nanofibers.

Helical supramolecular architectures play important structural and functional roles in biological systems. The helicity of synthetic molecules can be tuned mainly by the chiral manipulation of the system. However, tuning of helicity by the achiral unit of the molecules is less studied.

Exploring the druggability of oxidized low-density lipoprotein (ox-LDL) receptor, LOX-1, a proatherogenic drug target involved in atherosclerosis.

Lectin-like oxidized low-density lipoprotein (ox-LDL) receptor 1 (LOX-1) is a vital scavenger receptor involved in ox-LDL binding, internalization, and subsequent proatherogenic signaling leading to cellular dysfunction and atherosclerotic plaque formation. Existing data suggest that modulation of ox-LDL - LOX-1 interaction can prevent or slow down atherosclerosis. Therefore, we utilized computational methods such as multi-solvent simulation and characterized two top-ranked druggable sites.

Zinc ion inhibits SARS-CoV-2 main protease and viral replication .

Zinc deficiency is linked to poor prognosis in COVID-19 patients while clinical trials with zinc demonstrate better clinical outcomes. The molecular targets and mechanistic details of the anti-coronaviral activity of zinc remain obscure. We show that zinc not only inhibits the SARS-CoV-2 main protease (Mpro) with nanomolar affinity, but also viral replication.

Ambient Room Temperature Phosphorescence and Thermally Activated Delayed Fluorescence from a Core-Substituted Pyromellitic Diimide Derivative.

Triplet harvesting under ambient conditions plays a crucial role in improving the luminescence efficiency of purely organic molecular systems. This requires elegant molecular designs that can harvest triplets either via room temperature phosphorescence (RTP) or by thermally activated delayed fluorescence (TADF). In this context, here we report a donor core-substituted pyromellitic diimide (acceptor) derivative as an efficient charge-transfer molecular design from the arylene diimide family as a triplet emitter.

Arylene Diimide Phosphors: Aggregation Modulated Twin Room Temperature Phosphorescence from Pyromellitic Diimides.

Arylene diimide derived ambient organic phosphors are seldom reported despite their potential structural characteristics to facilitate the triplet harvesting. In this context, highly efficient room temperature phosphorescence (RTP) from simple, heavy-atom substituted pyromellitic diimide derivatives in amorphous matrix and crystalline state is reported here. Multiple intermolecular halogen bonding interactions among these phosphors, such as halogen-carbonyl and halogen-π resulted in the modulation of phosphorescence, cyan emission from monomeric state and orange-red emission from its aggregated state, to yield twin RTP emission.