Journal of Molecular Structure最新文献

{"title":"Design, synthesis, structural characterization, and DFT approach of a new bis-Schiff base-derived sulfonyldianiline: Thermal and nonlinear optical performances in a fluid system","authors":"Amir Hussein Ali ,&nbsp;Ahmed Majeed Jassem ,&nbsp;Qusay M.A. Hassan ,&nbsp;C.A. Emshary ,&nbsp;H.A. Sultan ,&nbsp;Wisam A. Radhi","doi":"10.1016/j.molstruc.2026.145604","DOIUrl":"10.1016/j.molstruc.2026.145604","url":null,"abstract":"<div><div>The synthesis, structural elucidation, thermal calculations, and nonlinear optical (NLO) activity of a new bis-Schiff base<strong>-</strong>derived sulfonyldianiline, (<em>Z</em>)-3-((4-((4-((<em>E</em>)-(4-(benzyloxy) benzylidene) amino) phenyl) sulfonyl)phenyl)imino)-2-indolinone (<strong>5</strong>) (C₃₄H₂₅N₃O₄S) using spectroscopic, thermal, and NLO techniques, are reported. The structure of the entitled compound (<strong>5</strong>) was deduced based on NMR, FT-IR, mass, and UV–visible spectra. The DFT-calculations in terms of the NLO descriptors such as mean polarizability, α_o (esu), and hyperpolarizability, β (esu) are investigated. The thermal properties viz., thermal conductivity (K), viscosity (η_i), and specific heat capacity (c_p) with values of 0.21-0.27 W/mK, 1.3 × 10⁻³ Pa.sec at 27.7 °C, and 1631 J/Kg. K respectively, are obtained. Heat conduction in the sample studied using two-dimensional transient heat conduction model that is solved using Finite Difference Method (FDM). The NLO properties of bis-Schiff base chromophore (<strong>5</strong>) are studied <em>via</em> the passage of the laser beam (473 nm) based on the diffraction patterns (DPs) viz., beam power input, its wave front, and temporal evolution. The resulted diffraction patterns (DPs) are assessed numerically using Fresnel-Kirchhoff integral based on Fraunhofer approximation solved using MATLAB system. The numerically obtained results agree well with experimental findings. In addition, the all-optical switching (AOS) is evaluated using three laser beams. Overall, the results indicate that the target chromophore (<strong>5</strong>) is recommended for upcoming optical applications such as AOS viz., static and dynamic.</div></div>","PeriodicalId":16414,"journal":{"name":"Journal of Molecular Structure","volume":"1360 ","pages":"Article 145604"},"PeriodicalIF":4.7,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146192670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis, spectral characterization, structures, and computation of 1-methyl-/1,3-dimethyl-5-(p-Nitro-phenylazo)-6-aminouracils and Silver(I) complexes","authors":"Nishan Das ,&nbsp;Abid Hossain ,&nbsp;Brojogopal Chand ,&nbsp;Susanta Ghanta ,&nbsp;Lesław Sieroń ,&nbsp;Waldemar Maniukiewicz ,&nbsp;Tarun K. Misra","doi":"10.1016/j.molstruc.2026.145595","DOIUrl":"10.1016/j.molstruc.2026.145595","url":null,"abstract":"<div><div>Two distinct crystal structures of a newly synthesized 1-methyl-5-(<em>p</em>-nitro-phenylazo)-6-aminouracil (<strong>LH₃</strong>) and the previously known 1,3-dimethyl-5-(<em>p</em>-nitro-phenylazo)-6-aminouracil (<strong>LH₂</strong>) were investigated. While LH₃ has tetragonal symmetry with space group I4₁/a, LH₂ has monoclinic symmetry with space group P2₁/c. Interestingly, unlike LH₃, the projection of the azo-function relative to the 6-amino group of uracil in LH₂ is entirely reversed. Both are <em>E</em>-conformer and planar and the plane of angle between the phenyl and the uracil rings reveals that LH₂ (5.78(5)°) is more planar than LH₃ (= 17.93(5)°). They are supposed to be formed distorted tetrahedral Ag(I) nitrate complexes, [Ag^I(LH₃)(NO₃)(H₂O)] (<strong>1</strong>) with LH₃ and [Ag^I(LH₂)(NO₃)(H₂O)].4H₂O (<strong>2</strong>) with LH₂; the exact masses are 476.27 and 563.38, respectively, obtained from an ESI-mass spectrometry study. The complexes exhibit a strong stretching frequency of ν(NO₃) at 1384 cm^-1. The DFT structural optimizations of all the compounds were studied using the B3LYP method in DMSO solvent. The theoretically extracted bond parameters of the ligands are found in good agreement with their crystal structure values; for instance, the RMSD values for the azo-bond lengths are 0.0004 for the LH₃ and 0.003 for the LH₂. According to the DFT analysis, the ligands are preferably coordinated to Ag(I) through azo-N and uracil-O. The other two coordinating ligands are a water molecule and a nitrate ion. The Ag(I)-O(nitrate) bond lengths of 2.38385 Å for <strong>1</strong> and 2.56253 Å for <strong>2</strong>, are comparable to values found in the literature. The coordination sites are supported by the molecular electrostatic potentials (MEP) and natural bond orbital (NBO) analysis. The NBO charges on the uracil-O and azo-N atoms increase from -0.574 and -0.199 to -0.653 and -0.256 in <strong>1</strong> and -0.593 and -0.144 to -0.636 and -0.202 in <strong>2</strong>. In addition, due to the coordination environment the developed NBO charges on Ag-atom is 0.687 e for <strong>1</strong> and 0.737 e for <strong>2</strong>.</div></div>","PeriodicalId":16414,"journal":{"name":"Journal of Molecular Structure","volume":"1360 ","pages":"Article 145595"},"PeriodicalIF":4.7,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146192674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The impact of supramolecular ordering on the thermotropic behavior of asymmetrical azomethine liquid crystals","authors":"Manuela Maria Iftime,&nbsp;Ramona Lungu,&nbsp;Dana Bejan,&nbsp;Sergiu Shova","doi":"10.1016/j.molstruc.2026.145605","DOIUrl":"10.1016/j.molstruc.2026.145605","url":null,"abstract":"<div><div>The paper reports the impact of positional isomerism on the thermotropic behavior of two asymmetrical azomethines bearing a chlorine substituent and a flexible butyl chain. The isomers were synthesized <em>via</em> acid-catalyzed condensation and structurally characterized by FTIR, NMR, UV-vis spectroscopy, and single-crystal X-ray diffraction (SC-XRD). Thermal investigations using TGA, DSC, and POM revealed that the compounds exhibit enantiotropic or monotropic liquid crystalline behavior, forming Smectic A and Smectic B mesophases during cooling. It was demonstrated that the orientation of the imine linkage significantly influences the conjugation degree of the rigid core and the strength of intermolecular forces. Specifically, the isomer with more extended conjugation stabilizes the higher-ordered S_B phase, while conformational disorder in the flexible chains, favors the lower-ordered S_A phase.</div></div>","PeriodicalId":16414,"journal":{"name":"Journal of Molecular Structure","volume":"1360 ","pages":"Article 145605"},"PeriodicalIF":4.7,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146192445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A uranyl carboxyphosphonate framework exhibiting luminescence intensity, luminescence lifetime and SHG triple-response","authors":"Ge-Hua Wen,&nbsp;Hui Chen","doi":"10.1016/j.molstruc.2026.145597","DOIUrl":"10.1016/j.molstruc.2026.145597","url":null,"abstract":"<div><div>To date, no reports have been documented on triple-response temperature sensing based on luminescence intensity, luminescence lifetime, and nonlinear optics (NLO) in coordination polymers (CPs) or metal-organic frameworks (MOFs). In this study, we successfully synthesized a three-dimensional (3D) uranyl carboxyphosphonate framework, (ImH)₂[(UO₂)₅(2-pmb)₄] (<strong>1</strong>), by introducing imidazole (Im) molecules into the reaction system of 2-(phosphonomethyl)benzoic acid (2-pmbH₃) with uranyl ions. Compound <strong>1</strong> crystallizes in the polar space group <em>Cmc</em>2₁, featuring a 3D framework constructed by uranyl phosphonate chains along the <em>b</em>-axis interconnected with trinuclear uranyl carboxylate units within the <em>ac</em>-plane. Protonated imidazole molecules serve as counterions, orderly arranged between uranyl chains along the <em>b</em>-direction. The shortest U···U distance within the structure is 4.91 Å. Photoluminescence studies reveal that compound <strong>1</strong> exhibits characteristic green luminescence at room temperature, demonstrating a favorable quantum yield (8.46%) and an exceptionally long luminescence lifetime (4164.3 μs). Furthermore, its second harmonic generation (SHG) response of 0.67 × KDP at room temperature confirms the non-centrosymmetric structure. Temperature-dependent studies demonstrate that compound <strong>1</strong> enables triple-response optical thermometry through luminescence intensity (80–300 K), luminescence lifetime (80–300 K), and second harmonic generation (SHG) signal (80–160 K).</div></div>","PeriodicalId":16414,"journal":{"name":"Journal of Molecular Structure","volume":"1360 ","pages":"Article 145597"},"PeriodicalIF":4.7,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146192448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Solvation shell collapse and molecular asymmetry dictate polymorph selection in citric acid","authors":"Estevão Genito João Macaringue ,&nbsp;Tiantian Tao ,&nbsp;Yujiang Xie ,&nbsp;Weiwei Tang ,&nbsp;Junbo Gong","doi":"10.1016/j.molstruc.2026.145592","DOIUrl":"10.1016/j.molstruc.2026.145592","url":null,"abstract":"<div><div>Control over polymorph selection is critical in materials science, yet the molecular mechanisms governing the nucleation of specific crystal forms from solution remain elusive. Citric acid (CA) presents a compelling case of non-classical nucleation where the metastable anhydrous phase dominates outcomes even under conditions thermodynamically favoring the stable monohydrate, violating Ostwald’s rule of stages. Herein, we combine variable-temperature multi-nuclear NMR (¹H, ¹³C), FTIR spectroscopy, and molecular dynamics (MD) simulations to elucidate how site–specific molecular asymmetry dictates this selection. We demonstrate that in dilute solutions, ionization of the terminal carboxyl groups prevents the formation of the cooperative water networks required for the monohydrate lattice, kinetically favoring anhydrous nucleation. As concentration approaches saturation, the system undergoes a solvation shell collapse, shifting toward a neutral, central-mediated self-association regime that generates dense, super-shielded cluster cores. Crucially, we reveal that this specific neutrality enables the terminal carboxyl arms to act as dominant hydration interfaces, capturing the solvent necessary for monohydrate nucleation within incipient clusters. However, this hydration mechanism is thermally fragile: experimental pH profiling and site-specific chemical shift sensitivity analysis (Δδ) demonstrate that elevated temperatures cause reionization by introducing charged defects that destabilize the monohydrate pathway and kinetically limit the system back to anhydrous motif. These findings provide a unified molecular mechanism linking solution speciation with macroscopic phase selection, proposing a framework for site-specific responsiveness that may serve as a model for controlling polymorphism in other complex organic acids through the exploitation of intrinsic molecular asymmetry.</div></div>","PeriodicalId":16414,"journal":{"name":"Journal of Molecular Structure","volume":"1360 ","pages":"Article 145592"},"PeriodicalIF":4.7,"publicationDate":"2026-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146192490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Water and thermal stability Eu-MOF for highly selectively sensing Fe3+ ions and phosphor-converted LED","authors":"Jing Li ,&nbsp;Xiao-Liang Yang ,&nbsp;Jia-Chen Liu ,&nbsp;Xin-Ci Wu ,&nbsp;Xiao-Tian Wei ,&nbsp;Ya-Pan Wu ,&nbsp;Xiao-Gang Yang","doi":"10.1016/j.molstruc.2026.145596","DOIUrl":"10.1016/j.molstruc.2026.145596","url":null,"abstract":"<div><div>Lanthanide metal–organic frameworks (Ln-MOFs) are widely recognized as excellent photo-functional materials, primarily owing to their bright emission, long luminescence lifetime, narrow and line-like emission. However, the urgent issues of water stability and thermal quenching still pose formidable challenges. Herein, one novel Ln-MOF [Eu2(CPIA)3(2,2′-bipy)(H2O)3]∙2H2O (<strong>Eu-MOF</strong>) can be facilely synthesized by the mixture of Eu2O3, (3-(3-carboxyphenyl) isonicotinic acid (H2CPIA) and 2,2′-bipyridine (2,2′-bipy) under hydrothermal conditions. It has a 3D porous framework with two kinds of channels being occupied by the 2,2′-bipy and uncoordinated pyridine rings of CPIA ligands. The water and thermal stability measurements exhibit that the <strong>Eu-MOF</strong> can maintain 95.50% and 80.05% of its initial luminescent intensity after remaining socked in water for 20 days and being heated to 150 °C, respectively. These physicochemical stability ensure it ideal candidate applied in the detection/recognition of Fe3+ ions, and solid-state lighting.</div></div>","PeriodicalId":16414,"journal":{"name":"Journal of Molecular Structure","volume":"1360 ","pages":"Article 145596"},"PeriodicalIF":4.7,"publicationDate":"2026-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146192475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural, and computational insights of 2,3-dihydropyrazine derivatives as antitubercular agents","authors":"R. Reshwen Shalo ,&nbsp;A.R. Karthiga ,&nbsp;S. Divyabharathi ,&nbsp;K. Rajeswari ,&nbsp;T. Vidhyasagar","doi":"10.1016/j.molstruc.2026.145594","DOIUrl":"10.1016/j.molstruc.2026.145594","url":null,"abstract":"<div><div>Tuberculosis (TB) remains a major global health challenge, even with the presence of effective treatment options. The increasing demand for more efficient anti-tubercular drugs highlights the need for improved strategies in combating this disease. The present study focuses on developing effective anti-tubercular agents through the synthesis and characterization of two dihydropyrazine derivatives: 2-(4-fluorophenyl)-3-methyl-5,6-diphenyl-2,3-dihydropyrazine (<strong>4a</strong>) and 2-phenyl-3-isopropyl-5,6-diphenyl-2,3-dihydropyrazine (<strong>4b</strong>). These compounds were analysed using spectral techniques and single-crystal X-ray diffraction (SC-XRD), and their potential anti-tubercular activity was evaluated through molecular docking studies. Single-crystal X-ray diffraction analysis reveals that the pyrazine rings in molecules <strong>4a</strong> and <strong>4b</strong> adopt a screw-boat conformation. Crystallographic investigations revealed that crystal packing in <strong>4a</strong> is primarily stabilized by C<img>H···π interactions, while <strong>4b</strong> exhibits C<img>H···H<img>C, and C<img>H···π interactions. Density Functional Theory (DFT) calculations at the B3LYP/6–311++ <em>G</em>(d, p) level was employed to evaluate molecular geometry, Frontier Molecular Orbitals (FMOs), Molecular Electrostatic Potential (MEP), and Global Chemical Reactivity parameters. The MEP maps provided insight into the reactive sites. The optimized geometrical parameters showed good agreement with the SC-XRD results. Hirshfeld surface analysis and 2D fingerprint plots, revealed that non-covalent interactions play a crucial role in stabilizing the crystal packing, with significant contributions from H<strong>···</strong>H contacts in <strong>4a (</strong>56.7%) and in <strong>4b (</strong>68.1%). The energy framework analysis provided additional evidence highlighting the crucial role of these interactions in retaining crystal stability. Molecular docking studies targeting the Cytochrome P450 protein (PDB ID: <span><span>1EA1</span><svg><path></path></svg></span>) revealed strong antitubercular potential, exhibiting favourable binding affinities. <em>In silico</em> ADME predictions indicated that both compounds possess excellent pharmacokinetic properties<em>.</em> These findings provide valuable insights into the potential of these compounds to be developed as effective bioactive agents.</div></div>","PeriodicalId":16414,"journal":{"name":"Journal of Molecular Structure","volume":"1360 ","pages":"Article 145594"},"PeriodicalIF":4.7,"publicationDate":"2026-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146192406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A review of 9, 9-Dimethyl-9, 10-dihydroacridine (DMAC) derivatives as thermally activated delayed fluorescence emitters in OLED applications","authors":"Masoud Dehghanipour ,&nbsp;Zahra Nasresfahani","doi":"10.1016/j.molstruc.2026.145590","DOIUrl":"10.1016/j.molstruc.2026.145590","url":null,"abstract":"<div><div>Thermally Activated Delayed Fluorescence (TADF) has emerged as a game changer in the field of organic light-emitting diodes (OLEDs). By cleverly harnessing both singlet and triplet excitons, TADF offers a compelling pathway to achieve high internal quantum efficiencies (IQEs) without relying on expensive and often problematic rare-earth metals used in phosphorescent materials. This review focuses on TADF emitters utilizing at least one 9,9-Dimethyl-9,10-dihydroacridine (DMAC) unit as a donor and is structured according to different acceptor building blocks, including, triazines, pyrimidines, sulfones, carbonyls, anthraquinones, pyridines, borons, and others, along with material design strategies, device performance, and future prospects. The incorporation of acridine derivatives into OLED materials can enhance the efficiency and stability of light emission, making them promising candidates for next-generation display technologies. The distinctive planar structure of acridine allows for effective π-π stacking, facilitating charge transport and exciton formation in the organic layers. Furthermore, acridine's ability to emit light in a wide range of colors (red, green, blue, and white) is particularly valuable. Herein, the recent developments of DMAC derivatives is methodically summarized, that structure–property relationships focused on two fundamental factors of interest for TADF emitters, including, frontier molecular orbitals separation and minimal singlet–triplet energy gap (ΔE_ST) and OLED applications. It is anticipated that this review will provide a comprehensive overview of the role of this acridine analog in advancing OLED materials and present exciting possibilities for both scientific research and commercial applications.</div></div>","PeriodicalId":16414,"journal":{"name":"Journal of Molecular Structure","volume":"1360 ","pages":"Article 145590"},"PeriodicalIF":4.7,"publicationDate":"2026-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146192578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Syntheses, characterization, computational studies, DNA/protein binding, and assessment of antimicrobial potency of new Zinc(II) dithiocarbamates","authors":"Shafeeq Ur Rehman ,&nbsp;Ziaur Rehman ,&nbsp;Faisal Hayat ,&nbsp;Atif khalil ,&nbsp;Muhammad Arslan Zaheen ,&nbsp;Usman Ali ,&nbsp;Naifa Alenazi ,&nbsp;Hanan Alghibiwi","doi":"10.1016/j.molstruc.2026.145591","DOIUrl":"10.1016/j.molstruc.2026.145591","url":null,"abstract":"<div><div>The promising biocompatibility of Zn(II) dithiocarbamates prompted us to synthesize three new compounds of this class: bis[4-(2-methoxyphenyl)piperazine-1-carbodithioato-<em>k</em>² S,S']zinc(II) (<strong>1)</strong>, bis[4-(2-hydroxyoxyphenyl)piperazine-1-carbodithioato-<em>k</em>² S,S']zinc(II) <strong>(2)</strong>, and bis(benzylmethyl-1-carbodithioato-<em>k</em>² S,S']zinc(II) <strong>(3)</strong>. To elucidate the structures of these compounds, a variety of characterization techniques were employed, namely elemental analysis, UV-visible spectroscopy, FTIR, and both ¹H NMR and ¹³C NMR spectroscopy. Furthermore, the assessment of geometry and stability was carried out using DFT-based calculations. Molecular docking with CT-DNA, Vascular Endothelial Growth Factor Receptor (VEGFR2) and Epidermal Growth Factor Receptor (EGFR) have indicated their strong and specific interactions, underpinning their potential as anticancer agents. Multiple complementary assays, including UV-visible spectroscopy, cyclic voltammetry, and viscometry, have confirmed their high DNA-binding capability operating through distinct binding modes. The determination of key thermodynamic and kinetic parameters further validated their biological potential and also indicated the spontaneous nature of drug-DNA interaction. Additionally, complexes <strong>1-3</strong> exhibited excellent potential as antioxidant and antimicrobial (antibacterial and antifungal) agents. In nutshell, the biocompatible and the bioactive nature of Zn(II) dithiocarbamates (<strong>1-3</strong>) necessitates for further exploration in the domain of anticancer and antimicrobial research to gain in-depth understanding of their mechanism of action and challenges associated with their use.</div></div>","PeriodicalId":16414,"journal":{"name":"Journal of Molecular Structure","volume":"1360 ","pages":"Article 145591"},"PeriodicalIF":4.7,"publicationDate":"2026-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146192540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Methyl group dynamics and conformational flexibility in methacetin revealed by neutron spectroscopy","authors":"Jose E.M. Pereira ,&nbsp;Elena Boldyreva ,&nbsp;Boris A. Zakharov ,&nbsp;Hery Mitsutake ,&nbsp;Svemir Rudić ,&nbsp;Michael M. Koza ,&nbsp;Tilo Seydel ,&nbsp;Juergen Eckert ,&nbsp;Heloisa N. Bordallo","doi":"10.1016/j.molstruc.2026.145589","DOIUrl":"10.1016/j.molstruc.2026.145589","url":null,"abstract":"<div><div>The dynamics of functional groups within drug molecules influences their medicinal or toxicological effects, with methyl groups’ conformational changes affecting binding to active sites. Here, we combine inelastic neutron spectroscopy with density functional theory to investigate molecular dynamics and conformational flexibility of methacetin (C₉H₁₁NO₂), a member of the acetamide family that includes paracetamol (C₈H₉NO₂) and phenacetin (C₁₀H₁₃NO₂). Our results reveal that subtle variations in its crystal packing and hydrogen bonding lead to multiple conformations, with methyl group reorientations contributing significantly to the molecules dynamics. This study stresses the importance of integrating experimental and computational methods to understand the structural dynamics of pharmaceutical compounds and their implications for drug design.</div></div>","PeriodicalId":16414,"journal":{"name":"Journal of Molecular Structure","volume":"1360 ","pages":"Article 145589"},"PeriodicalIF":4.7,"publicationDate":"2026-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146192404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}