Molecules最新文献_第3页

Surface-Dependent Isotopic Adsorption of CO on α-Al₂O₃: Role of Weak Interactions and Zero-Point Energy. α-Al2O3对CO的表面依赖同位素吸附：弱相互作用和零点能的作用。

IF 4.2 2区化学

Molecules Pub Date : 2025-05-06 DOI: 10.3390/molecules30092067

Qun Yang, Xiyue Cheng, Qian Xu, Shuiquan Deng

{"title":"Surface-Dependent Isotopic Adsorption of CO on α-Al2O3: Role of Weak Interactions and Zero-Point Energy.","authors":"Qun Yang, Xiyue Cheng, Qian Xu, Shuiquan Deng","doi":"10.3390/molecules30092067","DOIUrl":"10.3390/molecules30092067","url":null,"abstract":"Carbon isotopes, particularly 13C, are critical for applications in food authentication, biomedical diagnostics, and metabolic research; however, their efficient separation remains challenging due to their low natural abundance. This study investigates the adsorption behavior of 12CO and 13CO on various low-index α-Al2O3 surfaces as a strategy for isotope separation. Density functional theory (DFT) calculations with D3 (BJ) dispersion corrections were employed to optimize surface models for five representative α-Al2O3 facets. Nine adsorption configurations were systematically evaluated by optimizing geometric structures, computing adsorption enthalpies with zero-point energy corrections, and performing Bader charge and charge density difference analyses to elucidate interfacial interactions. The results reveal that CO preferentially adsorbs in a vertical configuration via its carbon end at Al sites, with the (0001) surface exhibiting the lowest surface energy and most favorable adsorption characteristics. Furthermore, we found that facets with lower surface energy not only facilitate stronger CO adsorption but also demonstrate pronounced adsorption enthalpy differences between 12CO and 13CO, driven by vibrational zero-point energy disparities. These findings highlight the potential of low adsorption enthalpy surfaces, particularly (0001), (011¯2), and (112¯0), for enhancing isotope separation efficiency, providing valuable insights for the design of advanced separation materials.","PeriodicalId":19041,"journal":{"name":"Molecules","volume":"30 9","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12073176/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143973003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Quantitative ¹H and ¹³C NMR and Chemometric Assessment of ¹³C NMR Data: Application to Anabolic Steroid Formulations. 定量1H和13C核磁共振和13C核磁共振数据的化学计量学评估：在合成代谢类固醇制剂中的应用。

IF 4.2 2区化学

Molecules Pub Date : 2025-05-06 DOI: 10.3390/molecules30092060

Stéphane Balayssac, Gaëtan Assemat, Saïda Danoun, Myriam Malet-Martino, Véronique Gilard

{"title":"Quantitative 1H and 13C NMR and Chemometric Assessment of 13C NMR Data: Application to Anabolic Steroid Formulations.","authors":"Stéphane Balayssac, Gaëtan Assemat, Saïda Danoun, Myriam Malet-Martino, Véronique Gilard","doi":"10.3390/molecules30092060","DOIUrl":"10.3390/molecules30092060","url":null,"abstract":"This study investigates the potential of 1H and 13C NMR for the characterization and classification of anabolic androgenic steroids (AASs) in various formulations. First, twenty AAS formulations, including tablets, capsules, and injectable solutions, were analyzed using 1H NMR for the qualitative identification and quantification of active compounds. The results revealed discrepancies between the labeled and detected substances in several samples, highlighting issues related to product mislabeling and potential health risks. Then, twelve oil-based injectable formulations were examined using 13C NMR, demonstrating its effectiveness in differentiating and quantifying closely related steroid structures that cannot be discriminated with 1H NMR. A chemometric approach from 13C NMR data, based on a principal component analysis (PCA) and hierarchical cluster analysis (HCA), enabled the classification of samples and the identification of key active ingredients.","PeriodicalId":19041,"journal":{"name":"Molecules","volume":"30 9","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12074264/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143972983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Diffusion Coefficients and Activation Energies of Diffusion of Organic Molecules in Poly(lactic acid) Films. 有机分子在聚乳酸薄膜中的扩散系数和扩散活化能。

IF 4.2 2区化学

Molecules Pub Date : 2025-05-06 DOI: 10.3390/molecules30092064

Johann Ewender, Rafael Auras, Uruchaya Sonchaeng, Frank Welle

{"title":"Diffusion Coefficients and Activation Energies of Diffusion of Organic Molecules in Poly(lactic acid) Films.","authors":"Johann Ewender, Rafael Auras, Uruchaya Sonchaeng, Frank Welle","doi":"10.3390/molecules30092064","DOIUrl":"10.3390/molecules30092064","url":null,"abstract":"Poly(lactic acid) (PLA) is one of the most important bio-based and industrial compostable materials in food packaging. Its barrier properties towards oxygen and moisture are well documented. However, data on barrier properties of PLA towards organic molecules are scarce in the literature. This study investigated the diffusion of various organic molecules, including n-alkanes, 1-alcohols, 2-ketones, ethers, esters, amines, and aromatics, in two commercial PLA films with thicknesses of 20 µm and 30 µm. The diffusion coefficient (DP) values were determined from lag time in permeation tests conducted at temperatures ranging from 20 °C to 90 °C. The films were also characterized in terms of crystallinity, rigid and mobile amorphous fractions, and molecular weight. Activation energies (EA) were calculated based on the temperature dependence of the DP using the Arrhenius approach. In total, 290 DP values for 55 individual substances were determined, and 38 EA values were derived from these data. The EA correlated well with the molecular volume of the investigated substances. Moreover, the pre-exponential factor D0 showed a correlation with EA. These correlations enabled the establishment of diffusion modeling parameters for PLA, allowing the prediction of DP for untested substances. The diffusion behavior of PLA was further compared with the literature data for polyethylene terephthalate and polyethylene naphthalate, providing insights into the relative performance of these materials.","PeriodicalId":19041,"journal":{"name":"Molecules","volume":"30 9","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12074079/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144033133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Vanadyl Phthalocyanine as a Low-Temperature/Low-Pressure Catalyst for the Conversion of Fructose to Methyl Levulinate. 钒酞菁作为果糖转化为乙酰丙酸甲酯的低温/低压催化剂。

IF 4.2 2区化学

Molecules Pub Date : 2025-05-06 DOI: 10.3390/molecules30092065

Juan Luna, Mataz Alcoutlabi, Elizabeth Fletes, Helia Morales, Jason G Parsons

{"title":"Vanadyl Phthalocyanine as a Low-Temperature/Low-Pressure Catalyst for the Conversion of Fructose to Methyl Levulinate.","authors":"Juan Luna, Mataz Alcoutlabi, Elizabeth Fletes, Helia Morales, Jason G Parsons","doi":"10.3390/molecules30092065","DOIUrl":"10.3390/molecules30092065","url":null,"abstract":"In this study, a vanadyl phthalocyanine was synthesized and characterized using XRD, FTIR, and XPS, confirming the successful metalation of the phthalocyanine ring. XRD analysis showed the vanadyl phthalocyanine crystallized in the P-1 crystal lattice, with unit cell parameters a = 12.058 Å, b = 12.598 Å, and c = 8.719 Å, and the lattice angels were 96.203°, 94.941°, and 68.204°. FTIR spectroscopy supported the metalation by the disappearance of the N-H stretch of the non-metalated phthalocyanine. The vanadyl phthalocyanine was tested as a heterogenous catalyst for the conversion of fructose into methyl levulinate in H2SO4-methanol and HCl-methanol systems. The H2SO4-methanol reaction system catalyzed with the vanadyl phthalocyanine, and a zeroth-order rate constant of 1.10 × 10-6 M/s was observed, which was 1.74 times faster than sulfuric acid alone. The HCl-methanol system showed a zeroth-order of reaction with a rate constant of 2.33 × 10-6 M/s, which was 1.3 times faster than the HCl-methanol alone. While the HCl-methanol system showed a faster reaction rate, product distribution favored methyl levulinate formation in the H2SO4-methanol system. The main products identified were methyl levulinate and hepta-2,4-dienoic acid methyl ester, with a minor amount of hydroxymethylfurfural formed. These results suggest that vanadyl phthalocyanine can be effectively used as a catalyst to increase the rate of fructose conversion to methyl levulinate in either H2SO4 or HCl-methanol.","PeriodicalId":19041,"journal":{"name":"Molecules","volume":"30 9","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12073318/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144019593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Experimental Study of the Reactions of Br Atoms with Thiirane and Nitrosyl Chloride. 溴原子与硫烷和氯化亚硝基反应的实验研究。

IF 4.2 2区化学

Molecules Pub Date : 2025-05-06 DOI: 10.3390/molecules30092058

Yuri Bedjanian

{"title":"Experimental Study of the Reactions of Br Atoms with Thiirane and Nitrosyl Chloride.","authors":"Yuri Bedjanian","doi":"10.3390/molecules30092058","DOIUrl":"10.3390/molecules30092058","url":null,"abstract":"The kinetics of Br-atom reactions with C2H4S and ClNO were studied as a function of temperature at a total pressure of 2 Torr of helium using a discharge-flow system combined with mass spectrometry: Br + C2H4S → SBr + C2H4 (1) and Br + ClNO →BrCl + NO (2). The rate constant of reaction (1) was determined at T = 340-920 K by absolute measurements under pseudo-first-order conditions, either by monitoring the kinetics of Br-atom or C2H4S consumption in excess of C2H4S or of Br atoms, respectively, and by using a relative rate method: k1 = (6.6 ± 0.7) × 10-11 exp(-(2946 ± 60)/T) cm3molecule-1s-1 (where the uncertainties represent the precision at the 2σ level, the estimated total uncertainty on k1 being 15% at all temperatures). The rate coefficient of reaction (2), determined either from the kinetics of the formation of the reaction product, BrCl, or from the decays of Br-atoms in an excess of ClNO, showed non-Arrhenius behavior, being practically independent of temperature below 400 K and increasing significantly at temperatures above 500 K. The measured rate constant is well reproduced by a sum of two exponential functions: k2 = 1.2 × 10-11 exp(-19/T) + 8.0 × 10-11 exp(-1734/T) cm3 molecule-1 s-1 (with an estimated overall temperature-independent uncertainty of 15%) at T = 225-960 K.","PeriodicalId":19041,"journal":{"name":"Molecules","volume":"30 9","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12073443/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144063603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Electronic Interactions Between the Receptor-Binding Domain of Omicron Variants and Angiotensin-Converting Enzyme 2: A Novel Amino Acid-Amino Acid Bond Pair Concept. 组粒变异受体结合域与血管紧张素转换酶2之间的电子相互作用：一种新的氨基酸-氨基酸键对概念。

IF 4.2 2区化学

Molecules Pub Date : 2025-05-06 DOI: 10.3390/molecules30092061

Puja Adhikari, Bahaa Jawad, Wai-Yim Ching

{"title":"Electronic Interactions Between the Receptor-Binding Domain of Omicron Variants and Angiotensin-Converting Enzyme 2: A Novel Amino Acid-Amino Acid Bond Pair Concept.","authors":"Puja Adhikari, Bahaa Jawad, Wai-Yim Ching","doi":"10.3390/molecules30092061","DOIUrl":"10.3390/molecules30092061","url":null,"abstract":"SARS-CoV-2 remains a severe threat to worldwide public health, particularly as the virus continues to evolve and diversify into variants of concern (VOCs). Among these VOCs, Omicron variants exhibit unique phenotypic traits, such as immune evasion, transmissibility, and severity, due to numerous spike protein mutations and the rapid subvariant evolution. These Omicron subvariants have more than 15 mutations in the receptor-binding domain (RBD), a region of the SARS-CoV-2 spike protein that is important for recognition and binding with the angiotensin-converting enzyme 2 (ACE2) human receptor. To address the impact of these high numbers of Omicron mutations on the binding process, we have developed a novel method to precisely quantify amino acid interactions via the amino acid-amino acid bond pair (AABP). We applied this concept to investigate the interface interactions of the RBD-ACE2 complex in four Omicron Variants (BA.1, BA.2, BA.5, and XBB.1.16) with its Wild Type counterpart. Based on the AABP analysis, we have identified all the sites that are affected by mutation and have provided evidence that unmutated sites are also impacted by mutation. We have calculated that the binding between RBD and ACE2 is strongest in OV BA.1, followed by OV BA.2, WT, OV BA.5, and OV XBB.1.16. We also present the partial charge values for all 311 residues across these five models. Our analysis provides a detailed understanding of changes caused by mutation in each Omicron interface complex.","PeriodicalId":19041,"journal":{"name":"Molecules","volume":"30 9","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12073306/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144037329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Geometrical Evolution Pattern and Spectroscopic Properties of Terbium-Doped Germanium Anionic TbGe_n (n = 6-17) Nanoclusters: From Tb-Lined to Tb-Encapsulated Structures. 铽掺杂锗阴离子TbGen （n = 6-17）纳米团簇的几何演化模式和光谱性质：从tb衬里到tb封装结构。

IF 4.2 2区化学

Molecules Pub Date : 2025-05-06 DOI: 10.3390/molecules30092066

Chenliang Hao, Jucai Yang

{"title":"Geometrical Evolution Pattern and Spectroscopic Properties of Terbium-Doped Germanium Anionic TbGen (n = 6-17) Nanoclusters: From Tb-Lined to Tb-Encapsulated Structures.","authors":"Chenliang Hao, Jucai Yang","doi":"10.3390/molecules30092066","DOIUrl":"10.3390/molecules30092066","url":null,"abstract":"Developing advanced materials with enhanced performance through the doping of nanoclusters is a promising strategy. However, there remains an insufficient understanding of the specific effects induced by such doped nanoclusters, particularly regarding the structural evolution pattern after doping with rare-earth elements and their impact on performance. To solve this problem, we used first-principles calculation to study the structural evolution pattern and spectroscopic properties of anionic TbGen (n = 6-17) nanoclusters through the ABCluster global search technique coupled with the mPW2PLYP double-hybrid density functional theory. The results revealed that the geometrical evolution pattern is from the typical Tb-linked structures (for n = 10-13, in which Tb acts as a linker connecting two germanium sub-clusters) to Tb-centered cage configurations (for n = 14-17). The simulated photoelectron spectroscopy of anionic TbGe16 agrees well with its experimental counterpart. Furthermore, we calculated properties such as infrared spectroscopy, Raman spectroscopy, ultraviolet-visible (UV-vis) spectra, magnetism, charge transfer, the HOMO-LUMO gap, and relative stability. The results suggest that TbGe12- and TbGe16- clusters, with their remarkable stability and tunable photothermal properties, can serve as ideal building blocks for developing novel functional nanomaterials. These clusters demonstrate promising applications in solar photothermal conversion, photoelectric conversion, and infrared imaging technologies through their distinct one- and three-dimensional architectures, respectively.","PeriodicalId":19041,"journal":{"name":"Molecules","volume":"30 9","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12073666/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144006542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Visible Light-Driven Phenol Degradation via Advanced Oxidation Processes with Ferrous Oxalate Obtained from Black Sands: A Kinetics Study. 黑砂草酸亚铁高级氧化法降解苯酚动力学研究。

IF 4.2 2区化学

Molecules Pub Date : 2025-05-06 DOI: 10.3390/molecules30092059

Salomé Galeas, Víctor H Guerrero, Patricia I Pontón, Vincent Goetz

{"title":"Visible Light-Driven Phenol Degradation via Advanced Oxidation Processes with Ferrous Oxalate Obtained from Black Sands: A Kinetics Study.","authors":"Salomé Galeas, Víctor H Guerrero, Patricia I Pontón, Vincent Goetz","doi":"10.3390/molecules30092059","DOIUrl":"10.3390/molecules30092059","url":null,"abstract":"Ferrous oxalate dihydrate (α-FOD) was synthesized from Ecuadorian black sands for phenol removal from aqueous solutions. Visible light-driven photodegradation kinetics were studied by varying the initial pollutant concentration, solution pH, and α-FOD dosage and by adding peroxydisulfate (PDS), including quenching tests. A representative model of phenol photodegradation was obtained by the Langmuir-Hinshelwood mechanism over a large range of concentrations (apparent kinetic constant, k = 0.524 h-1). Almost complete removal was reached within 1 h under dark + 9 h under visible irradiation. The degradation rate was slightly affected by pH in the range of 3 to 9, with a significant improvement at pH 11 (k = 1.41-fold higher). The optimal α-FOD dosage was ~0.5 g/L. Two regimes were observed when using PDS: first, a heterogeneous Fenton-like process during the first few minutes after PDS addition; second, pure photocatalysis to completely remove the phenol. When comparing the two systems, without and with PDS, the half-life time for pure photocatalysis was 2.5 h (after the lamp was switched on). When adding PDS (1.0 mM), the half-life time was reduced to a few minutes (5 min after PDS addition, phenol removal was 66%). The photocatalyst presented remarkable degradation efficiency up to five repeated cycles.","PeriodicalId":19041,"journal":{"name":"Molecules","volume":"30 9","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12073611/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144012575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Design, Synthesis, and Biological Evaluation of New Analogs of Aurein 1.2 Containing Non-Proteinogenic Amino Acids. 含非蛋白质原性氨基酸的金莲蛋白1.2新类似物的设计、合成及生物学评价

IF 4.2 2区化学

Molecules Pub Date : 2025-05-05 DOI: 10.3390/molecules30092050

Nora Angelova, Ivan Iliev, Veronica Nemska, Tatyana Dzimbova, Nelly Georgieva, Dancho Danalev, Emilia Naydenova

{"title":"Design, Synthesis, and Biological Evaluation of New Analogs of Aurein 1.2 Containing Non-Proteinogenic Amino Acids.","authors":"Nora Angelova, Ivan Iliev, Veronica Nemska, Tatyana Dzimbova, Nelly Georgieva, Dancho Danalev, Emilia Naydenova","doi":"10.3390/molecules30092050","DOIUrl":"10.3390/molecules30092050","url":null,"abstract":"Extensive use of classical antibiotics has led to the growing emergence of many resistant strains of pathogenic bacteria. To combat this challenge, researchers have turned to the antimicrobial peptides (AMPs). Aurein 1.2 (GLFDIIKKIAESF-NH2) was demonstrated to have broad spectrum bi-functionality against bacterial and cancer cells. The Solid Phase Peptide Synthesis (Fmoc-strategy) was used for the synthesis of new analogs of aurein 1.2. The purity of all compounds was monitored by HPLC, and their structures were proven using mass spectrometry. Cytotoxicity and antiproliferative effects were studied using 3T3 NRU and MTT tests, respectively. The antibacterial activity was estimated against Gram-positive and Gram-negative bacteria using broth microdilution method in concentrations from 0 to 320 µg/mL to determine the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). The antiproliferative activity test shows that the peptide analog EH [Orn]8 has the highest activity (IC50 = 44 ± 38 μM) for the three cell lines studied (MCF-12F, MCF-7, and MDA-MB-231). The same compound exhibited good antimicrobial activity. The obtained results reveal that replacement of Lys with non-proteinogenic amino acids can increase both the potency and activity spectra of natural template peptides, making them suitable candidates for new drug development.","PeriodicalId":19041,"journal":{"name":"Molecules","volume":"30 9","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12074479/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144063584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Intramolecular Versus Intermolecular Diels-Alder Reactions: Insights from Molecular Electron Density Theory. 分子内与分子间Diels-Alder反应：来自分子电子密度理论的见解。

IF 4.2 2区化学

Molecules Pub Date : 2025-05-05 DOI: 10.3390/molecules30092052

Luis R Domingo, Patricia Pérez

{"title":"Intramolecular Versus Intermolecular Diels-Alder Reactions: Insights from Molecular Electron Density Theory.","authors":"Luis R Domingo, Patricia Pérez","doi":"10.3390/molecules30092052","DOIUrl":"10.3390/molecules30092052","url":null,"abstract":"The intramolecular Diels-Alder (IMDA) reactions of four substituted deca-1,3,9-trienes and one N-methyleneocta-5,7-dien-1-aminium with different electrophilic/nucleophilic activations have been studied within the Molecular Electron Density Theory (MEDT) and compared to their intermolecular processes. The topological analysis of the electron density and DFT-based reactivity indices reveal that substitution does not modify neither the electronic structure nor the reactivity of the reagents relative to those involved in the intermolecular processes. The analysis of the relative energies establishes that the accelerations found in the polar IMDA reactions follow the same trend as those found in the intermolecular processes. The geometries and the electronic structures of the five transition state structures involved in the IMDA reactions are highly similar to those found in the intermolecular processes. A relative interacting atomic energy (RIAE) analysis of Diels-Alder and IMDA reactions allows for the establishment of the substituent effects on the activation energies. Although the nucleophilic frameworks are destabilized, the electrophilic frameworks are further stabilized, resulting in a reduction in the activation energies. The present MEDT study demonstrates the remarkable electronic and energetic similarity between the intermolecular and intramolecular Diels-Alder reactions. Only the lower, unfavorable activation entropy associated with the latter renders it 104 times faster than the former.","PeriodicalId":19041,"journal":{"name":"Molecules","volume":"30 9","pages":""},"PeriodicalIF":4.2,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12073351/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143991242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0