Oxidation reactions catalyzed by O2-dependent enzymes are gaining increasing interest in the chemical industry due to their potential to provide a more selective, benign and sustainable alternative to the conventional chemical oxidation methods. O2-dependent enzymes, like oxidases and oxygenases, catalyze a versatile range of oxidative reactions using only molecular oxygen as oxidant. However, their practical application on larger scale has been limited up to this point, primarily due to factors like their low catalytic rates combined by a narrow substrate spectrum and low stability. Nonetheless, in recent years, enzyme engineering studies have made significant progress in addressing these challenges and moving O2-dependent enzymes closer towards industrial utilization. In this review, we aim to provide a concise overview of the most recent engineering approaches on O2-dependent enzymes. We will highlight recent studies that have targeted various aspects of O2-dependent enzymes including, activity, selectivity, stability, and substrate spectrum with a focus on engineering studies where the engineered enzymes catalyze synthetically valuable reactions.
An Indacenodithieno[3,2‐b]thiophene‐based Organic Dye for P‐type Dye‐Sensitized Solar Cells and Photoelectrochemical H2O2 Production
![An Indacenodithieno[3,2-b]thiophene-based Organic Dye for P-type Dye-Sensitized Solar Cells and Photoelectrochemical H2O2 Production](https://chemistry-europe.onlinelibrary.wiley.com/cms/asset/8e65c66a-fcd7-4e6e-8019-9c666a131d7b/cptc202300297-toc-0001-m.png)
A novel organic dye featuring an indacenodithieno[3,2-b]thiophene unit as the π-bridge, labeled as YB6, has been designed for p-type dye-sensitized solar cells (p-DSCs) and photoelectrochemical H2O2 production. Remarkably, it exhibits superior performance compared to the reference PB6 dye.
Abstract
Efficient photosensitizers are crucial for advancing solar energy conversion and storage technologies. In this study, we designed and synthesized a novel organic dye, denoted as YB6, for p-type dye-sensitized solar cells (p-DSCs) and photoelectrochemical H2O2 production. YB6 features an extended conjugated π-bridge derived from indacenodithieno[3,2-b]thiophene and exhibits notable advantages: a two-fold higher molar extinction coefficient at its main absorption peak and a broader absorption as compared to the PB6 dye. In p-type dye-sensitized NiO photoelectrochemical cells, the YB6-based device demonstrated superior performance as compared to the PB6-based device. It delivered nearly a 50 % higher H2O2 production over 5 hours. Furthermore, when fabricated into p-DSCs, the YB6-based device exhibited a 33 % higher power conversion efficiency. This enhancement is caused by suppressed charge recombination from the dye structure, which in turn may be traced to a larger thermodynamic up-hill process for recombination losses in the YB6-based system.
Lanthanide Amide Complexes Supported by the Bis‐tris(pyrazolyl)borate Ligand Environment
The specific synthetic conditions to successfully access primary lanthanide amides in the bis-hydrotris(1-pyrazolyl)borate ligand environment [Ln(Tp)2(NHArCF3)] 3-Ln (Ln=Y, Dy; ArCF3=C6H3(CF3)2-3,5) are reported by either metathesis of [Ln(Tp)2(OTf)] 1-Ln (OTf=CF3SO3) with K(NHArCF3) or protonolysis of [Ln(Tp)2(N′′)] 2-Ln (N′′=N(SiMe3)2) with H2NArCF3 in toluene.
Abstract
Synthesis of primary lanthanide amides in the bis-hydrotris(1-pyrazolyl)borate ligand environment has been achieved. Salt metathesis of [Dy(Tp)2(OTf)] 1-Dy (OTf=CF3SO3) with K(N′′) (N′′=N(SiMe3)2) in toluene yielded the [bis(silyl)]amide [Dy(Tp)2(N′′)] 2-Dy. Complexes 1-Ln and 2-Ln were both used to access primary lanthanide amides, where either metathesis of 1-Ln with K(NHArCF3) (ArCF3=C6H3(CF3)2-3,5) or protonolysis of 2-Ln with H2NArCF3 in toluene yielded [Ln(Tp)2(NHArCF3)] 3-Ln (Ln=Y, Dy). The synthesis of parent amides was also attempted, but the metathesis of 1-Y with NaNH2 yielded complicated reaction mixtures, but from which the dimeric parent amide [{Y(Tp)2(μ-NH2)}2] 4-Y and an ‘ate’-salt [{Y(Tp)2(μ 2-OTf)(μ 3-OTf)Na(THF)2}2] 5-Y were isolated. Full characterisation data are presented for all complexes, including the structure determination.
Schiff‐base Polymer Immobilized Ruthenium for Efficient Catalytic Cross‐coupling of Secondary Alcohols with 2‐amino‐ and γ‐aminobenzyl Alcohols to Give Quinolines and Pyridines
SNW-1, a Schiff–base porous polymer, has been impregnated with ruthenium trichloride for acceptor–free dehydrogenation coupling (ADC) of secondary alcohols with γ-amino- and 2-aminobenzyl alcohols to give pyridines and quinolines. This heterogenous catalyst exhibited high catalytic efficiency over repeated cycles with wide functional group tolerance.
Abstract
A Schiff–base porous polymer has been impregnated with ruthenium trichloride for acceptor–free dehydrogenation coupling (ADC) of secondary alcohols with γ-amino- and 2-aminobenzyl alcohols to give pyridines and quinolines. This heterogenous catalyst exhibited high catalytic efficiency over repeated cycles with wide functional group tolerance.
H2O2 Self‐supplying CaO2/CuO2/Fe3O4 Nanoplatform for Enhanced Chemodynamic Therapy of Cancer Cells
We have synthesized a hyaluronic acid (HA) modified CaO2/CuO2/Fe3O4 nanocomposite by a simple and flexible strategy. The H2O2 self-supplying and ⋅OH self-catalyzed nanocomposite exhibited favorable pH-controlled ⋅OH generation and excellent tumor growth inhibition ability, providing a potential nanotheranostics platform with active targeting and favorable therapeutic efficacy in tumor therapy.
Abstract
Due to the properties of hypoxia, lower pH, and higher hydrogen peroxide (H2O2) in the tumor microenvironment (TME), a wide variety of metal peroxide nanomaterials have got great attention for efficient TME-responsive and -regulated tumor therapy. However, a single species of metal peroxide is inadequate to realize high effective anticancer therapy. Herein, we have synthesized a hyaluronic acid (HA) modified CaO2/CuO2/Fe3O4 nanocomposite by a simple and flexible strategy. CaO2 can generate H2O2 by reacting with water in slightly acidic TME, and the self-supplying H2O2 can be catalyzed to generate ⋅OH by both Cu2+ and Fe2+ via Fenton-type reaction. Strongly oxidizing ⋅OH can induce tumor cells death for enhanced chemodynamic therapy (CDT). The H2O2 self-supplying and ⋅OH self-catalyzed nanocomposite exhibited favorable pH-controlled ⋅OH generation and excellent cancer cells growth inhibition ability, providing a potential nanotheranostics platform with active targeting and favorable therapeutic efficacy in tumor therapy.
An Isolable THF‐coordinated Dialkylgermanone
A stable dialkylgermanone was generated by mixing a solid of the corresponding dialkylgermylene and gaseous N2O. While the dialkylgermanone is marginally persistent in solution and gradually converts to its head-to-tail dimer at room temperature, the addition of THF to the dialkylgermanone provided an isolable THF-coordinated dialkylgermanone. The THF-coordinated dialkylgermanone reacts with H2O, THF, and B(C6F5)3 similar to the corresponding base-free two-coordinate dialkylsilanone. The dialkylgermanone undergoes deoxygenation in the presence of triphenylphosphine to provide the corresponding germylene and olefination upon treatment with phosphaylide Ph3PCHPh to afford the corresponding Ge=C bond compound (germa-Wittig reaction).
Nanoemulsion strategies in controlling fungal contamination and toxin production on grain corn using essential oils
Advancements in Olive‐derived Carbon: Preparation Methods and Sustainable Applications
In the realm of material science, carbon materials, especially olive-derived carbon (ODC), have become vital due to their sustainability and diverse properties. This review examines the sustainable extraction and use of ODC, a carbohydrate-rich by-product of olive biomass. We focus on innovative preparation techniques like pyrolysis, crucial for enhancing ODC's microstructure and surface properties. Variables such as activating agents, impregnation ratios, and pyrolysis conditions significantly influence these properties. ODC's high specific surface area renders it invaluable for applications in energy storage (in batteries and supercapacitors) and environmental sectors (water purification, hydrogen storage). Its versatility and accessibility underscore its potential for broad industrial use, marking it as a key element in sustainable development. This review provides a detailed analysis of ODC preparation methodologies, its various applications, and its role in advancing sustainable energy solutions. We highlight the novelty of ODC research and its impact on future studies, establishing this review as a crucial resource for researchers and practitioners in sustainable carbon materials. As global focus shifts towards eco-friendly solutions, ODC emerges as a critical component in shaping a sustainable, innovation-driven future.
Light Triggered Reversible Aggregation/Dispersion of Hydroxy Azo‐benzenes During Photo Switching: Solvent, Ions Assisted Dispersion, and Induced Quenching Emission
Photoswitching of hydroxy azobenzene derivatives was studied in different solvents. It was observed that in polar solvents, showed unexpectedly very slow trans⇆cis isomerization. Studies showed that aggregation⇆dispersion was the cause of unusual stabilities. The presence of ionic species was found to promote photoisomerization. Regular photoswitching was observed under non-polar conditions.
Abstract
Hydroxy azo-benzenes are very well known for their rapid trans⇆cis photoisomerization under polar solvents. In contrast, we synthesized two hydroxymethylated- hydroxyazobenzene derivatives and investigated their light-triggered photoisomerization and stability under polar solvents. The result showed just opposite behavior and very slow trans⇆cis isomerization was observed (minutes-days). Thus, the UV-vis spectrum revealed a very low decrease in the absorbance of π–π* transition. Surprisingly, the isomerization process became faster with the addition of ionic species. Here, we attempted to understand the underlying cause of the unusual photo-switching behavior. The presence of hydroxymethyl and fluorine substituents was found to have a significant effect on the stability of the trans and photo-isomerized cis products. Here, it was confirmed with NMR and DLS studies that the unusual photostability of trans compounds was caused by polar solvent-assisted aggregation (hydrodynamic radius, RH 5660–1720 nm) which underwent dispersion (RH, 220–68 nm) and formed a significant stable solvated photoproduct under photoirradiation. Furthermore, this aggregation-dispersion was found to be very slowly reversible. Further, the fluorescence emission demonstrated a characteristic dispersion-induced quenching. Regular photoswitching was observed under non-polar conditions in benzene where an expected blue shift of π–π* transition and an increase in the intensity of n–π* transitions.
Ultraviolet Light‐Assisted Decontamination of Chemical Warfare Agent Simulant 2‐Chloroethyl Phenyl Sulfide on Metal‐Loaded TiO2/Ti Surfaces
UV light emerges as a potent decontaminant for chemical warfare agents (CWAs). Utilizing TiO2/Ti as a catalyst, this study investigates UV photocatalytic decontamination efficiency against 2-chloroethyl phenyl sulfide. Introduction of Au, Pt, and Cu onto TiO2/Ti surface is explored. UVC light reveals eight secondary byproducts, while Au overlay notably boosts activity under UVB, uncovering valuable insights for CWA decontamination.
Abstract
The application of ultraviolet (UV) light for the decontamination of chemical warfare agents (CWAs) has gained recognition as an effective method, especially for treating hard-to-reach areas where wet chemical methods are impractical. In this study, TiO2/Ti was employed as a model catalyst, which was contaminated with 2-chloroethyl phenyl sulfide (CEPS), and subjected to photocatalytic decontamination using both UVB and UVC light. Additionally, photocatalytic decontamination efficiency by introducing Au, Pt, and Cu onto the TiO2/Ti surface was explored. During the photodecomposition process under UVC light, at least eight distinct secondary byproducts were identified. It was observed that the introduction of overlayer metals did not significantly enhance the photodecomposition under UVC light instead overlaid Au exhibited substantially improved activity under UVB light. Whereas, photodecomposition process under UVB light, only five secondary products were detected, including novel compounds with sulfoxide and sulfone functional groups. This novel study offers valuable insights into the generation of secondary products and sheds light on the roles of overlayer metals and photon wavelength in the photodecontamination process of CWA.