ChemistryOpen最新文献

The cover feature shows a ruthenium(II) polypyridine complex dissolved in 1-ethyl-3-methylimidazolium acetate under X-ray irradiation. The long hydrophobic alkyl chains of the complex act as buoys, pulling it towards the liquid/vacuum interface, as proven by ARXPS measurements. More details can be found in the Research Article by Hans-Peter Steinrück, Federico J. Williams, and co-workers (DOI: 10.1002/open.202400092).

In the cover picture, the plasma jet located on the liquid surface transfers plasma-generating chemical species to the liquid as the plume facing the liquid. Depending on the condition of the liquid (conductivity, bubble content, etc.), the intensity of the plasma can be strengthened or weakened. In addition, the survival time of plasma-generated chemical species can also be determined. More details can be found in the Research Article by Joo Young Park, Jin Hee Bae, and Seunghun Lee (DOI: 10.1002/open.202300213).

[cn]daisy chain molecular muscle architectures are self-assemblies of hermaphrodite monomers, which usually contain a macrocycle unit linked to a molecular thread that contains sites of interactions - i. e. molecular stations - for the macrocycle. In these multiply threaded structures, altering with control the affinity between macrocycles and stations allows for contraction and extension of the molecule, which is reminiscent of the operation of a muscle. Besides, the field that consists of combining helix and template-containing rods to design foldaxane supramolecular assemblies is still underexplored. By using foldamer units as surrogates for macrocycles, Gan et al. reported the first supramolecular muscle-like foldamer-containing switch that can adopt, after chemical stimulus, either a contracted co-conformational state or a degenerate-like state for which a slow exchange occurred between the contracted and the stretched state.

Metal corrosion is a challenge for the world with heavy impacts on the economy. Study on the development of effectiveness anticorrosion additives is a promising strategery for the protection industry. This research focuses on the modification of hydrotalcite Mg-Al (HT) loading tannic acid (TA) with 3-(trimethoxy silyl) propyl methacrylate organo-silane (TMSPM) for applicating as an anti-corrosion additive for epoxy coating on the steel substrate. The suitable ratio of HT and modifiers was investigated and the suitable content of modified HT in epoxy matrix was found based on mechanical properties of the epoxy-based coating. The characteristics of modified HT were assessed through infrared (IR) spectroscopy, X-ray diffraction pattern (XRD), scanning electron microscopy (SEM), thermal gravimetry analysis (TGA), water contact angle (WCA), dynamic light scattering (DLS). Detailly, HT-TA3-S3 shows good stability in distilled water when HT/TA was modified with TMSPM which makes Zeta potential decreases significantly. Besides, SEM analysis presented HT-TA-S has a cylindrical shape about of 500 nm. Moreover, the crystallite size of HT/TA after being modified by TMSPM decreases sharply. All of these prove successfully synthesize HT loading TA with modified TMSPM. Water contact angle (WCA) decreases in case of loading TA and increases in case of modifying with TMSPM (WCA changed from HT (116.3°) to HT-TA (102.4°) and HT-TA-S (120.1°) which indicates the increased hydrophobicity of the sample. The obtained results showed HT/TA was modified successfully with TMSPM. The modification affected the size distribution and surface properties of HT nanoparticles while it did not impact on the crystal structure of HT. After incorporating modified HT/TA into the epoxy coating, the adhesion of coating to steel substrate was improved significantly. Consequently, the adhesion of epoxy/3 wt. % modified HT/TA coating was increased 3 times as compared to epoxy neat (from 0.76 MPa to 2.77 MPa). In addition, the relative hardness and gloss retention of epoxy/3 wt. % modified HT/TA coating reached the maximum values as compared to the others. Owing to salt spraying results, the epoxy/3 wt. % modified HT/TA exhibited an excellent anticorrosion ability for the steel substrate. All the above results show the potential of HT nanoparticles loading TA modified with TMSPM as anticorrosive additives for protective coatings on steel substrates.

Three cationic Gold(I)-NHC complexes with potential anticancer properties were studied using DFT with B3LYP functional in combination with two basis sets, LanL2DZ and SDD. Obtained equilibrium geometries and computed IR spectra were found in excellent agreement with previously reported x-ray structures and experimental IR spectral data. NBO population analysis showed gold(I) has a charge deficiency of 0.26-0.30 e. All three complex cations are polar, with dipole moment values ranging from 6.8 to 7.4 Debye. Regardless of some structural differences in their co-ligands, all three complex cations have remarkably similar HOMO-LUMO energy gaps, with values ranging from 5.2 to 5.4 eV, confirming they are chemically stable and that they share an almost identical stability. Long-range intramolecular interactions Au ⋅⋅⋅H-X (X=N or C) in all three cationic complexes were identified. Both basis sets employed in this study were found equally effective in producing reliable results.

Isoguanosine (isoG) is a natural structural isomer of guanosine (G) with significant potential for applications in ionophores, genetics, gel formation, and cancer therapy. However, the cost of commercially available isoG on a gram scale is relatively high. To date, a detailed method for the large-scale preparation of high-purity isoG has not been reported. This study presented a simple and convenient approach for the large-scale synthesis of isoG through the diazotization of 2,6-diaminopurine riboside with sodium nitrite and acetic acid at room temperature. Further, this method could synthesize isoG derivatives (2'-fluoro-isoguanosine (1) and 2'-deoxy-isoguanosine (2)) from 2,6-diaminopurine nucleoside derivatives using diazotization. The structural information of natural and modified nucleosides is crucial for the modification and substitution of DNA/RNA. This study obtained the single-crystal structure of isoG for the first time and analyzed it in detail using microcrystal electron diffraction. The three-dimensional supramolecular structure of isoG adopted similarly base-pair motifs from π-π stacking interaction of diverse layers, intramolecular hydrogen bonding, and distinct hydrogen bonding interactions from sugar residues. This study has contributed to further isoG modification and its applications in medicinal chemistry and materials.

Rationale: Quinolone antibiotics are extensively used clinically for human treatment and in agriculture. However, improper and excessive use can lead to the persistence of quinolone residues in animal tissues, potentially accumulating in the human body and posing health risks. Investigating the correlation between mass spectrometry cleavage patterns and molecular structural features enhances the analytical framework for detecting trace or unknown impurities in quinolones.

Methods: To collect data, we employed triple quadrupole linear ion trap mass spectrometry in electrospray positive ion mode. Primary mass spectrometry scanning was utilized to confirm parent ions, while secondary mass spectrometry scanning enabled the observation of fragment ions. The cleavage characteristics and pathways of the compounds were inferred from accurate mass-to-charge ratios obtained from both primary and secondary mass spectrometry.

Results: Under soft ionization conditions, the compounds generally exhibited characteristic fragment ions of [M+H-H₂O]⁺, [M+H-CO]⁺, and [M+H-H₂O-CO]⁺. Additionally, subtle variations were observed in each compound due to differences in modifying groups. For instance, upon deacidification, the piperazine ring structure underwent breakage and rearrangement, yielding fragment ion peaks devoid of neutral molecules such as C₂H₅N, C₃H₇N, or C₄H₈N. Notably, compounds featuring a cyclopropyl substituent group at the N-1 position typically exhibited characteristic fragments resulting from the loss of the cyclopropyl radical (⋅C₃H₅). Moreover, substituents at the N-1 and C-8 positions, when linked to form a six-membered carbocyclic ring, were prone to cleavage, releasing the neutral C₃H₆ molecule.

Conclusion: Quinolone antibiotics share structural similarities in their parent nuclei, leading to partially similar cleavage pathways. Nevertheless, distinct cleavage patterns emerge due to variations in functional groups. According to the difference of mass spectrometry cleavage patterns, it can provide an identification basis for the measured detection of antibiotics.

Cigarette smoke contains a large number of chemicals, including both flavor components and harmful substances. The mainstream smoke (MSS) generated by smoking is directly inhaled by individuals, making it crucial to establish an effective method for smoke detection and analysis. One promising technique for analyzing smoke is MPT-MS (Microwave plasma torch mass spectrometry). This approach offers several advantages in accurately detecting the composition of cigarette smoke. By combining MPT-MS with a smoke pumping device, we can achieve real-time online detection of smoke components. We successfully detected 22 flavor compounds present in the smoke. These compounds contribute to the distinct taste of cigarettes. Moreover, we identified 2 polycyclic aromatic hydrocarbons (PAHs) in the smoke. PAHs are known carcinogens and are of great concern in terms of their potential health risks. The successful detection and identification of flavor compounds and PAHs using our method confirm the online detection capability of MPT-MS. This approach provides an efficient and reliable means for analyzing the complex composition of cigarette smoke. By utilizing MPT-MS, we can gain valuable insights into the chemical composition of cigarette smoke and can inform the development of strategies and policies aimed at reducing the harmful effects of smoking and protecting public health.

This study explores the synthesis of ZnS nanoparticles through the thermal decomposition of zinc ethyl carbamate complex. Results indicate that ZnS nanoparticles are formed at 300 °C as evident in the XRD and SEM analysis. These ZnS nanoparticles have potential applications in opto-electronic devices. More information can be found in the Research Article by Selina Ama Saah and co-workers.