Distortion-Controlled Redshift of Organic Dye Molecules

Advancements in enzymatic reaction-mediated microbial transformation

Enzymatic reaction-mediated microbial transformation has emerged as a promising technology with significant potential in various industries. These technologies offer the ability to produce enzymes on a large scale, optimize their functionality, and enable sustainable production processes. By utilizing microbial hosts and manipulating their genetic makeup, enzymes can be synthesized efficiently and tailored to meet specific industrial requirements. This leads to enhanced enzyme performance and selectivity, facilitating the development of novel processes and the production of valuable compounds. Moreover, microbial transformation and biosynthesis offer sustainable alternatives to traditional chemical methods, reducing environmental impact and promoting greener production practices. Microbial transformations enrich drug candidate diversity and enhance active ingredient potency, benefiting the pharmaceutical industry. Continued advancements in genetic engineering and bioprocess optimization drive further innovation and application development in Enzymatic reaction-mediated microbial transformation. The integration of AI for predicting enzymatic reactions and optimizing pathways marks a promising direction for future research. In summary, these technologies have the potential to revolutionize several industries by providing cost-effective, sustainable solutions.

Brownmillerite Calcium Ferrite, a Promising Perovskite-Related Material in the Degradation of a Tight Dye under Ambient Conditions

Evaluation of effective and low-cost materials as catalysts to combat the threat of pollution is a significant and growing trend. With this aim, we have synthesized calcium ferrite brownmillerite by wet preparation approach as a catalyst for pollution. The structural analysis is established by the X-ray diffraction of Ca2 Fe2 O5 , whereas the tetrahedral and octahedral sites band stretching for ferrite specimen has been deduced using FTIR. The bandgap energy has been estimated by the Tauc relation (2.17 eV). Ca2 Fe2 O5 brownmillerite exhibits a BET surface area of 10 m2 /g and a BJH pore volume of 0.121 cm3 /g with the average particle size of 70 nm. Importantly, the alizarin Red S dye degradation has been studied using the prepared ferrite catalyst, under dark ambient conditions and without the presence of any acidic or basic additives. Degradation is also supported by both FTIR and TOC analysis. Surface properties of brownmillerite Ca2 Fe2 O5 have been characterized using electronic spectroscopy and CO2 temperature programmed desorption (TPD) analysis and revealed that the basic surface of brownmillerite Ca2 Fe2 O5 offers active sites that are suitable for degradation processes. All results show that the preparation of brownmillerite Ca2 Fe2 O5 via the Pechini method is suitable to produce fine surfaces and pores with nanosized particles.

Carbonyl-Based Redox-Active Compounds as Organic Electrodes for Batteries: Escape from Middle-High Redox Potentials and Further Improvement?

Extracting─from the vast space of organic compounds─the best electrode candidates for achieving energy material breakthrough requires the identification of the microscopic causes and origins of various macroscopic features, including notably electrochemical and conduction properties. As a first guess of their capabilities, molecular DFT calculations and quantum theory of atoms in molecules (QTAIM)-derived indicators were applied to explore the family of pyrano[3,2-b]pyran-2,6-dione (PPD, i.e., A0) compounds, expanded to A0 fused with various kinds of rings (benzene, fluorinated benzene, thiophene, and merged thiophene/benzene). A glimpse of up-to-now elusive key incidences of introducing oxygen in vicinity to the carbonyl redox center within 6MRs─as embedded in the A0 core central unit common to all A-type compounds─has been gained. Furthermore, the main driving force toward achieving modulated low redox potential/band gaps thanks to fusing the aromatic rings for the A compound series was discovered.

Tunable Nanoparticles with Aggregation-Induced Emission Heater for Precise Synergistic Photothermal and Thermodynamic Oral Cancer Therapy of Patient-Derived Tumor Xenograft

The fluorophores in the second near-infrared (NIR-II) biological window (1000 - 1700 nm) show great application prospects in the fields of biology and optical communications. However, both excellent radiative transition and nonradiative transition cannot be achieved simultaneously for the majority of traditional fluorophores. Herein, tunable nanoparticles formulated with aggregation-induced emission (AIE) heater are developed rationally. The system can be implemented via the development of an ideal synergistic system that can not only produce photothermal from nonspecific triggers but also trigger carbon radical release. Once accumulating in tumors and subsequently being irradiated with 808 nm laser, the nanoparticles (NMB@NPs) encapsulated with NMDPA-MT-BBTD (NMB) are splitted due to the photothermal effect of NMB, leading to the decomposition of azo bonds in the nanoparticle matrix to generate carbon radical. Accompanied by second near-infrared (NIR-II) window emission from the NMB, fluorescence image-guided thermodynamic therapy (TDT) and photothermal therapy (PTT) which significantly inhibited the growth of oral cancer and negligible systemic toxicity is achieved synergistically. Taken together, this AIE luminogens-based synergistic photothermal-thermodynamic strategy brings a new insight into the design of superior versatile fluorescent NPs for precise biomedical applications and holds great promise to enhance the therapeutic efficacy of cancer therapy.

Highly efficient charge transport across carbon nanobelts

Carbon nanobelts (CNBs) are a new form of nanocarbon that has promising applications in optoelectronics due to their unique belt-shaped π-conjugated systems. Recent synthetic breakthrough has led to the access to various CNBs, but their optoelectronic properties have not been explored yet. In this work, we study the electronic transport performance of a series of CNBs by incorporating them into molecular devices using the scanning tunneling microscope break junction technique. We show that, by tuning the bridging groups between the adjacent benzenes in the CNBs, we can achieve remarkably high conductance close to 0.1 G₀, nearly one order of magnitude higher than their nanoring counterpart cycloparaphenylene. Density functional theory-based calculations further elucidate the crucial role of the structural distortion played in facilitating the unique radial π-electron delocalization and charge transport across the belt-shaped carbon skeletons. These results develop a basic understanding of electronic transport properties of CNBs and lay the foundation for further exploration of CNB-based optoelectronic applications.

Tuning the UV/Vis Absorption Spectra of Electrochromic Small Molecular Radicals Through Bridge Modulation

Studies on the optical properties of donor-bridge-acceptor (DBA) materials in their radical anion state are rare but important. Such investigations can help to extend the application of DBA materials to opto-electrochemical devices and no longer limit them to optical physics research. In this work, a series of new DBA materials, TACzs, for overcoming this limitation are reported. All TACzs show strong intramolecular charge transfer (ICT) in their photoexcited states, leading to noticeable solvatochromism. Besides, the electronic structures of their radical anions show great variability, displaying different absorption spectra and diverse colors. Moreover, the potential application of TACzs as electrochromic and electro-fluorochromic materials are discussed. This work demonstrates that manipulating the π bridge between the donor and acceptor in the DBA system is an effective pathway not only to tailor the ICT properties of materials in their neutral state, but also to tune the absorption characteristics of their radical anion state, which makes them very promising for applications in electroluminescent and electrochemical devices.

Distortion-Controlled Redshift of Organic Dye Molecules

It is shown, quantum chemically, how structural distortion of an aromatic dye molecule can be leveraged to rationally tune its optoelectronic properties. By using a quantitative Kohn-Sham molecular orbital (KS-MO) approach, in combination with time-dependent DFT (TD-DFT), the influence of various structural and electronic tuning parameters on the HOMO-LUMO gap of a benzenoid model dye have been investigated. These parameters include 1) out-of-plane bending of the aromatic core, 2) bending of the bridge with respect to the core, 3) the nature of the bridge itself, and 4) π-π stacking. The study reveals the coupling of multiple structural distortions as a function of bridge length and number of bridges in benzene to be chiefly responsible for a decreased HOMO-LUMO gap, and consequently, red-shifting of the absorption wavelength associated with the lowest singlet excitation (λ≈560 nm) in the model cyclophane systems. These physical insights together with a rational approach for tuning the oscillator strength were leveraged for the proof-of-concept design of an intense near-infrared (NIR) absorbing cyclophane dye at λ=785 nm. This design may contribute to a new class of distortion-controlled NIR absorbing organic dye molecules.