We report an unprecedented result of self-aggregation of [Pt(L1)Cl] (HL1 = 1,3-di(5-carboxy-2-pyridyl)benzene) triggered by CO2 in basic aqueous solution. The color of basic aqueous solution containing [Pt(L1)Cl] changes from yellow to blue-green during the aggregation resulted from a reaction with CO2 in air. Upon CO2 gas bubbling, strong and broad absorption bands of aggregate assigned to the metal-metal-to-ligand charge transfer transition appeared at 701 and 1152 nm. Recrystallization of [Pt(L1)Cl] from Na2CO3 aqueous solution afforded polymorphic crystals of red and blue-green forms. A single X-ray crystallography revealed that the red form of crystal consists of a Pt–Pt stacked dimer bridged by CO32– ion and one of the carboxy groups of L1 is deprotonated. An elemental analysis provided evidence that the blue-green crystal is constructed by linear array consisting of the [Pt(L2)(CO3)]3– (HL2 = 1,3-di(5-carboxylate-2-pyridyl)benzene) units. The formation process of blue-green aggregate in aqueous solution was monitored through a transient absorption spectrum, and the absorption of aggregates involved in the spectral change were examined by a global analysis. A singular value decomposition and kinetic analysis provide that there are four species resulted from the self-assembling reaction in the solution and the maximal degree of aggregation is at least 32-mer.
[ASAP] Single-Particle ICP-TOFMS with Online Microdroplet Calibration: A Versatile Approach for Accurate Quantification of Nanoparticles, Submicron Particles, and Microplastics in Seawater
Analytical Chemistry
DOI: 10.1021/acs.analchem.3c02785
Reaction induced conformational change in polyindole: Polyindole/PVA film as biomimetic sensors of temperature and electrical energetic condition.
The influence of surrounding temperature and electrical energetic condition on the conformational movements (cooperative actuation) of polyindole is verified using a polyindole-coated polyvinyl alcohol (PIN/PVA) film. Chronopotentiometric studies reveals that the consumed electrical energy during the reaction varies linearly with the change in working temperature. The influence of temperature on the reversible conformational movements of the polymer chain is related to the charge consumed during the reaction. The logarithmic dependence of reversible redox charge obtained from coulovoltammogram with inverse of temperature further proved the temperature sensing characteristics and the influence of temperature on the cooperative actuation of the PIN/PVA film. The conformational relaxation increases as the temperature increases through hosting higher number of counter anions with the solvent molecule. The extension of the redox reaction or charge consumption was found to decrease as the scan rate increases. The double logarithmic relation between the consumed redox charge and the scan rate has proved that the electrical energetic condition can influence the conformational movement or the extension of the redox reaction in a reversible manner. The results suggest that the PIN/PVA film can act as a biomimetic macro molecular sensor of working temperature and electrical energetic condition as biological muscles do.
Biomedical potential of hydrothermally synthesized zinc oxide nanoparticles for antifungal evaluation and cytotoxicity analysis
The graphical abstract present that study was conducted to identify the efficacy of hydrothermally synthesized ZnO NPs against the pathogenic fungi Fusariumincarnatum (MT682502) and Aspergillus niger (MT675916) isolated from the capsicum and tomato, respectively, and identified through morphological and molecular analysis. The toxicity evaluation of ZnO NPs was also examined against the human embryonic kidney (HEK293) cell line for their safe use.
As nanotechnology gains popularity in medicine, there is a growing concern that small nanoparticles (NPs) could accumulate and penetrate deep into the human body, posing potential risks to various organs. To ensure safe usage and assess potential hazards, it is crucial to conduct a toxicological evaluation of ZnO NPs on human organs such as the kidney. The present study involved the synthesis of ZnO NPs by using the hydrothermal method. Pure and crystalline phase was confirmed by X-ray diffraction (XRD). The SEM images displayed less agglomerated surface morphology, implying that the NPs were distributed relatively evenly and exhibited a plate-like shape. Two pathogenic fungi Fusarium incarnatum and Aspergillus niger were isolated from the capsicum and tomato, respectively, and identified through morphological and molecular analysis. The antimycotic property of synthesized ZnO NPs were examined against Fusariumincarnatum (MT682502) and Aspergillus niger (MT675916) and showed decreased microbial growth after 9 days of incubation. The toxicological evaluation of ZnO NPs on a human embryonic kidney (HEK293) cell line showed 88% cell viability with 10 μg/ml, leading to the safe use of ZnO NPs.
Critical Assessment of pH‐Dependent Lipophilicity Profiles of Small Molecules: Which One Should We Use and In Which Cases?
Lipophilicity is a physicochemical property with wide relevance in drug design, computational biology, and food, environmental and medicinal chemistry. Lipophilicity is commonly expressed as the partition coefficient for neutral molecules, whereas for molecules with ionizable groups, the distribution coefficient (D) at a given pH is used. The logDpH is usually predicted using a pH correction, while often ignoring the apparent ionic partition [[EQUATION]]. In this work, we studied the impact of [[EQUATION]] on the prediction of both the experimental lipophilicity of small molecules and experimental lipophilicity-based applications and metrics such as lipophilic efficiency (LipE), distribution of spiked drugs in milk products, and pH-dependent partition of water contaminants in synthetic passive samples such as silicones. Our findings show that better predictions are obtained by considering the apparent ionic partition. In this context, we developed machine learning algorithms to determine the cases that [[EQUATION]] should be considered. The results indicate that small, rigid, and unsaturated molecules with logPN close to zero, which present a significant proportion of ionic species in the aqueous phase, were better modeled using the apparent ionic partition [[EQUATION]]). Finally, our findings can serve as guidance to the scientific community working in early-stage drug design, food, and environmental chemistry
Enantioselective Synthesis of Indol‐3‐yl‐piperidines using Amine‐Catalyzed [4+2] Annulation Between Glutaraldehyde and C3‐Indolyl‐imines
A simple and straightforward method is developed for the enantioselective synthesis of indol-3-yl-piperidine. The reaction proceeds through a proline-catalyzed direct Mannich reaction between glutaraldehyde and C3-indolyl-imines, followed by intramolecular reductive cyclization as an overall [4+2] annulation in one-pot fashion. A series of indol-3-yl-piperidine have been accessed with good yields (up to 71%) and high enantioselectivity (up to >99% ee).
[ASAP] Stacking Faults in an O2-type Cobalt-Free Lithium-Rich Layered Oxide: Mechanisms of the Ion Exchange Reaction and Lithium Electrochemical (De)Intercalation
Chemistry of Materials
DOI: 10.1021/acs.chemmater.3c01426
[ASAP] Integrated Microwell Array-Based Microfluidic Chip with a Hand-Held Smartphone-Controlled Device for Nucleic Acid Detection
Analytical Chemistry
DOI: 10.1021/acs.analchem.3c03525
Adsorption Mechanism of Benzene Derivatives by Pagoda[n]arenes
Despite the widespread use in industrial production, benzene derivatives are harmful to both human beings and the environment. The control of these substances has become an important subject of scientific researches. This study introduces a new approach for adsorption and separation of benzene derivatives utilizing supramolecular materials based on pagoda[n]arene. Density functional theory (DFT) calculations were employed to investigate the molecular recognition mechanism of benzene derivatives by pagoda[4]arenes and pagoda[5]arenes (Pa[4]As and Pa[5]As). It was discovered that Pa[4]As and Pa[5]As can effectively accommodate benzene derivatives through non-covalent interactions, leading to the formation of stable host-guest complexes. Additionally, molecular dynamics (MD) simulations revealed that both crystalline and non-crystalline supramolecular aggregates of Pa[4]As and Pa[5]As possess the ability to adsorb benzene derivatives and maintain the stability of the adsorption. Moreover, increasing the temperature causes benzene derivatives to desorption from the adsorbing aggregates, and thus to achieve reutilization of the adsorbent materials.
[ASAP] Porosity as a Morphology Marker to Probe the Degradation of IrO2 Anode Catalyst Layers in Proton Exchange Membrane Water Electrolyzers
Chemistry of Materials
DOI: 10.1021/acs.chemmater.3c01524