Journal of Molecular Structure最新文献

{"title":"Spectroscopic, structural, optical, thermal, and dielectric properties of piperazinium 3-carboxy-4-hydroxybenzenesulfonate monohydrate","authors":"R. Rajkumar ,&nbsp;S. Suresh ,&nbsp;Ramki Chakaravarthy ,&nbsp;D. Pradhabhan ,&nbsp;P. Selvaraju ,&nbsp;P. Kavitha","doi":"10.1016/j.molstruc.2026.145356","DOIUrl":"10.1016/j.molstruc.2026.145356","url":null,"abstract":"<div><div>The present work focuses on growth and characterization of Piperazinium 3-carboxy-4-hydroxybenzenesulfonate monohydrate (PSA) crystals, synthesized successfully using the slow evaporation solution growth method. XRD analysis confirmed the crystalline nature and revealed the unit cell parameters, indicating good structural order suitable for optical applications. The UV–Vis-NIR absorption spectrum is recorded in the range of 300–600 nm, exhibited a sharp cutoff at 335 nm and high transparency in the visible region and suitability of PSA crystal for optoelectronic and photonic applications. Thermogravimetric analysis is confirmed that the crystal remains thermally stable up to its decomposition temperature, ensuring durability under operational conditions. Microhardness measurement indicated that PSA crystal mechanically is a soft material and favoring easy to make device fabrication. Third-order nonlinear optical properties were investigated using the Z-scan technique yielded a nonlinear absorption coefficient (β) of 0.03 × 10⁻³ cm/W and a nonlinear refractive index (n₂) of 6.55 × 10⁻⁸ cm²/W confirming the materials strong third order nonlinearity. Dielectric studies revealed a stable frequency dependent dielectric response and physical- electronic parameters such as plasma energy (ℏωp), Penn gap (EP), Fermi energy (EF) and polarizability (α) were estimated to understand the electronic polarizability behavior. The combined structural integrity, optical transparency, thermal stability and third -order non-linear response suggest that PSA crystal is a promising candidate for optical limiting behavior, photonic switching and dielectric device applications.</div></div>","PeriodicalId":16414,"journal":{"name":"Journal of Molecular Structure","volume":"1358 ","pages":"Article 145356"},"PeriodicalIF":4.7,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981235","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, crystal structure and thermal properties of azole-based energetic materials","authors":"Zhen-Li Yang ,&nbsp;Ya-Dong Yao ,&nbsp;Wu-Quan Meng ,&nbsp;Zu-Jia Lu ,&nbsp;Jian-Guo Zhang","doi":"10.1016/j.molstruc.2026.145346","DOIUrl":"10.1016/j.molstruc.2026.145346","url":null,"abstract":"<div><div>The structures of 3-amino-5-hydrazino-1H-1,2,4-triazolium dihydrochloride (<strong>1</strong>) and 3-amino-5-hydrazino-1H-1,2,4-triazolium 5-nitraminotetrazolate (<strong>2</strong>) were further corroborated by single-crystal X-ray diffraction. Elemental analysis, mass spectra, FT-IR and differential scanning calorimetry studies were performed to characterize the synthesized energetic salts. New energetic derivatives, consisting of 1,2,4-triazole and tetrazole rings, explosophoric azo or nitroamino groups, and nitrogen-rich anion (cation), were successfully synthesized using straightforward and efficient chemical methodologies. The as-prepared energetic salts <strong>2</strong> and 3-amino-5-hydrazino-1H-1,2,4-triazolium 5,5′-azotetrazolate (<strong>3</strong>) possess advantageous measured densities and exceptionally elevated heats of formation, endowing them with outstanding detonation characteristics: detonation velocities of 8981 and 8082 m·s^-1, and detonation pressures of 32.9 and 27.1 GPa, respectively. The combination of these results, including insensitive mechanical sensitivity and notable high nitrogen contents ranging from 68.8% to 80.0%, suggests that these energetic salts hold potential as environmentally friendly substitutes for traditional explosives. Additionally, DSC and TG were used to probe the thermal-decomposition pathways of the salts, and an isoconversional protocol coupled with nonlinear regression furnished the corresponding differential kinetic mechanism functions.</div></div>","PeriodicalId":16414,"journal":{"name":"Journal of Molecular Structure","volume":"1358 ","pages":"Article 145346"},"PeriodicalIF":4.7,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981120","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":"Dinuclear Zn(II) Schiff base complexes derived from m-phenylenediamine: Structure, photophysical properties and potential for selective detection of picric acid","authors":"Ninh Thi Minh Giang ,&nbsp;Tran Ngoc Dung ,&nbsp;Luc Van Meervelt ,&nbsp;Tan Le Hoang Doan ,&nbsp;Pham Do Chung ,&nbsp;Le Thi Hong Hai","doi":"10.1016/j.molstruc.2026.145335","DOIUrl":"10.1016/j.molstruc.2026.145335","url":null,"abstract":"<div><div>Five dinuclear Zn(II) complexes containing Schiff base ligands derived from <em>m</em>-phenylenediamine were synthesized and structurally characterized by elemental analysis, ESI-MS, IR, ¹H NMR, ¹³C NMR spectra and SC X-ray diffraction. In these complexes, Zn(II) ions coordinate to the ligands through N_imine and O_phenolic atoms in a 1:1 ratio. Photophysical studies revealed that all complexes exhibit a single emission band in the range of 453-527 nm, with ZnL5 displaying the strongest emission, ZnL2 the weakest and the remaining complexes showing intermediate emission efficiencies in the investigated solvents. In the solid state, the emission quantum yields decrease in the order <strong>ZnL5</strong> (52.6 %) <strong>&gt; ZnL4</strong> (33.3 %) <strong>&gt; ZnL1</strong> (28.2 %) <strong>&gt; ZnL2</strong> (17 %) <strong>&gt; ZnL3</strong> (2 %). The excited-state lifetimes of the complexes in both the solid state (0.87-4.45 ns) and in solution (0.62-3.50 ns) fall within the nanosecond timescale, confirming the fluorescent nature of the emission process. Furthermore, <strong>ZnL5</strong> exhibits a selective detection ability toward picric acid with a detection limit of 0.53 µM (approximately 121 ppb). Quantum-chemical calculations were carried out to examine the structural and optical properties of a series of Zn(II) complexes (<strong>ZnL1–ZnL5</strong>). The optimized ground- and excited-state geometries revealed that most complexes remain structurally rigid after excitation, while <strong>ZnL2</strong> undergoes noticeable distortions that are consistent with a larger reorganization energy and weaker luminescence. Time-dependent DFT further confirms that fluorescence in all cases originates primarily from a HOMO → LUMO transition. Taken together, the results highlight <strong>ZnL5</strong> as the most efficient red-emitting complex in the series, whereas <strong>ZnL2</strong> is limited by nonradiative decay associated with structural relaxation.</div></div>","PeriodicalId":16414,"journal":{"name":"Journal of Molecular Structure","volume":"1358 ","pages":"Article 145335"},"PeriodicalIF":4.7,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981129","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":"Switch-on selective detection of Zn2+ and Cd2+ ions by a thiosemicarbazide-based probe with promising breast cancer cell cytotoxicity","authors":"Mohd Arbaz Tyagi ,&nbsp;Mohd Mustaqeem ,&nbsp;Kanishka Kashyap ,&nbsp;Md. Najbul Hoque ,&nbsp;Bhaskar Nath ,&nbsp;Jehova Jire L. Hmar ,&nbsp;Jugal Bori","doi":"10.1016/j.molstruc.2026.145353","DOIUrl":"10.1016/j.molstruc.2026.145353","url":null,"abstract":"<div><div>A novel fluorescent Schiff base of thiosemicarbazide moiety, namely (E)-2-(4-chloro-2-hydroxybenzylidene)-N-(naphthalen-2-yl) hydrazine-1-carbothioamide (<strong>L</strong>), was designed and synthesized via the simple condensation reaction of 4-(1-naphthyl)-3-thiosemicarbazide with 4-chloro-2-hydroxybenzaldehyde. The fluorescent probe <strong>L</strong> exhibited a highly sensitive and selective fluorescence “turn-on” response toward Zn²⁺ and Cd²⁺metal ions, with a distinct color change from colorless to bright cyan under UV light. The detection limits were calculated and found to be 0.062 µM and 0.121 µM for both Zn²⁺ and Cd²⁺ ions, respectively. To determine the recyclability of the probe <strong>L,</strong> the induced reversible “turn-off” fluorescence responses were performed with the help of TBAP, also highlighting the molecular logic gate behaviour of the probe <strong>L</strong>. While the metal–ligand coordination modes were confirmed by FTIR, ¹HNMR titration, FLS, single-crystal XRD and mass spectrometric analytical techniques, the molecular docking studies demonstrated a strong binding affinity of <strong>L</strong> toward human hemoglobin. Additionally, test paper strips coated with <strong>L</strong> allowed rapid and visual detection of Zn²⁺ and Cd²⁺ ions under UV illumination. However, in vitro cytotoxicity studies against MCF-7 breast cancer cells revealed an IC₅₀ value of 7.013 ± 0.05 µM, demonstrating that the probe <strong>L</strong> possesses significant anticancer potential in addition to its excellent sensing properties. Thus, this work establishes sensor <strong>L</strong> as a highly efficient, reversible, and biocompatible fluorescent probe for Zn²⁺ and Cd²⁺ ion detection with potential anticancer applications.</div></div>","PeriodicalId":16414,"journal":{"name":"Journal of Molecular Structure","volume":"1358 ","pages":"Article 145353"},"PeriodicalIF":4.7,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146036333","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":"Growth, structural and nonlinear optical properties of lithium potassium ammonium sulphate single crystal for ultraviolet-active optoelectronic applications","authors":"Krishnamoorthy Sivaramasundaram ,&nbsp;Senthuran Karthick Kumar ,&nbsp;Santhanakrishnan Suresh ,&nbsp;Nalandhiran Pugazhenthiran ,&nbsp;Jemini Arumugam ,&nbsp;Devakumar Balaji ,&nbsp;Sekar Thambidurai","doi":"10.1016/j.molstruc.2026.145352","DOIUrl":"10.1016/j.molstruc.2026.145352","url":null,"abstract":"<div><div>Single crystal of LiK_0.93(NH₄)_0.07SO₄ was grown through a slow evaporation solution growth technique and its structural, vibrational and optical properties were investigated for the first time. XRD analysis disclosed that the grown crystal pertains to hexagonal system having P6₃ non-centrosymmetric space group. The FTIR and Raman spectra were recorded and analyzed for the confirmation of lithium (LiO₂ and LiO₄), ammonium (NH₄⁺) and sulphate (SO₄²⁻) functional groups and their corresponding symmetric/asymmetric stretching and bending vibrational modes in the grown LiK_0.93(NH₄)_0.07SO₄ single crystal. The present investigation revealed key structural insights that the partial substitution of K⁺ ions by NH₄⁺ ions in the lattice of the LiK_0.93(NH₄)_0.07SO₄ single crystal combined with the presence of Li⁺ ions led to subtle modifications in lattice parameters and vibrational spectra that could correlate with the observed high optical transparency, wide direct band gap energy (5.1 eV), enhanced SHG efficiency (1.47 × KDP), and favourable LDT values. Thus, this study, through compositional tailoring, offers new perspectives on enhancing functional applications of lithium sulphate family single crystals. Appreciable absorption properties in the UV region, minimal defect-induced attenuation, wide optical band gap energy, high second harmonic generation efficacy and better laser damage threshold potential make the grown LiK_0.93(NH₄)_0.07SO₄ single crystal a highly promising material for UV light dependent optoelectronic applications.</div></div>","PeriodicalId":16414,"journal":{"name":"Journal of Molecular Structure","volume":"1358 ","pages":"Article 145352"},"PeriodicalIF":4.7,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981239","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":"Microwave-assisted synthesis of indanone-based mannich base derivatives: In Silico study, evaluations of dual enzyme inhibition, drug-likeness, cytotoxicity, and selectivity properties","authors":"Mehtap Tugrak Sakarya ,&nbsp;Halise Inci Gul ,&nbsp;Hiroshi Sakagami ,&nbsp;Yusuf Sert ,&nbsp;Selma Sarac ,&nbsp;Ilhami Gulcin","doi":"10.1016/j.molstruc.2026.145363","DOIUrl":"10.1016/j.molstruc.2026.145363","url":null,"abstract":"<div><div>In the present study, two series of mono Mannich bases (<strong>C1-C5</strong> and <strong>CPM1-CPM5</strong>) were synthesized by reacting 2-(3-hydroxybenzylidene)-2,3-dihydro-1<em>H</em>-inden-1-one (C) with paraformaldehyde and secondary amines. Amine parts were replaced with <em>N</em>-methylpiperazine, morpholine, piperidine, pyrrolidine, dimethylamine, and substituted piperazines (<strong>C1-C5, CPM1-CPM5</strong>). <em>In vitro</em> cytotoxicity of the compounds was tested against oral cancer cell lines (Ca9–22, HSC-2) and normal oral cells (HGF, HPLF) using the MTT assay. According to potency selectivity expression (<em>PSE</em>) values, <strong>C5</strong> (21.6) and <strong>CPM1</strong> (19.2) showed the best selective cytotoxicity. All compounds exhibited significantly lower <em>K_i</em> values than the reference inhibitor acetazolamide (AZA), which showed <em>K_i</em> values of 183.39 ± 19.71 nM against hCA I and 104.60 ± 27.60 nM against hCA II, indicating superior inhibitory potency of the tested compounds. Among the <strong>C1-C5</strong> series, <strong>C1</strong> was identified as the most potent inhibitor against hCA I (<em>K_i</em> = 65.057 ± 7.750 nM). Within the CPM series, <strong>CPM4</strong> showed the strongest inhibition against hCA I (<em>K_i</em> = 48.368 ± 20.23 nM), while <strong>CPM3</strong> exhibited the highest potency against hCA II (<em>K_i</em> = 37.966 ± 5.301 nM), outperforming AZA in both isoforms. Against AChE, all compounds exhibited markedly stronger inhibitory activity than the reference inhibitor tacrine (<em>K_i</em> = 58.85 ± 12.1 nM). Among the tested compounds, <strong>C2</strong> and <strong>CPM4</strong> were identified as the most potent inhibitors in their respective series, with <em>K_i</em> values of 2.3811 ± 1.015 nM and 2.6962 ± 0.495 nM, respectively. Molecular docking supported these results: <strong>C1</strong> showed strong binding to hCA II (ΔG = –10.5 kcal/mol, <em>K_i</em> = 20.1 nM), <strong>CPM3</strong> was also selective for CA II, and <strong>CPM4</strong> stabilized AChE binding through H-bonds and π–π interactions (ΔG = –10.3 kcal/mol, <em>K_i</em> = 28.1 nM). Overall, Mannich bases displayed distinct binding modes consistent with their potent inhibition.</div></div>","PeriodicalId":16414,"journal":{"name":"Journal of Molecular Structure","volume":"1358 ","pages":"Article 145363"},"PeriodicalIF":4.7,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146036100","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":"Dinuclear zinc(II) Schiff base complex: Synthesis, spectroscopic characterization, crystallographic analysis, and computational insights","authors":"A. Ayyappan ,&nbsp;M. Savitha Lakshmi ,&nbsp;S. Mahalakshmi ,&nbsp;Shobhana Krishnaswamy ,&nbsp;S. Arockiasamy","doi":"10.1016/j.molstruc.2026.145354","DOIUrl":"10.1016/j.molstruc.2026.145354","url":null,"abstract":"<div><div>A dinuclear zinc(II) Schiff base complex, [Zn(L-1)₂]₂, was synthesised using a one-pot method with 5-chlorosalicylaldehyde, n-butylamine, and zinc(II) acetate. The crystal structure obtained from single crystal X-ray diffraction (SCXRD) analysis confirmed that the zinc(II) complex crystallised in the monoclinic space group <em>P</em>2₁/<em>c</em> with a distorted trigonal bipyramidal geometry. It was characterised by various techniques, including elemental analysis, UV–Vis, FTIR, ¹H, and ¹³C NMR spectroscopy. The thermogravimetric analysis (TGA) revealed that the complex was thermally stable, yielding a 5.7% residue at 374 °C in a single-step decomposition. It showed a sharp melting between 140 and 143 °C as evidenced by the DTA. Hirshfeld surface analysis (HSA) indicated that the major contributions to the surface included H<strong>^…</strong>H, H<strong>^…</strong>Cl, C<strong>^…</strong>H, and C<strong>^…</strong>Cl contacts, accounting for 96.4%. DFT analysis showed the HOMO-LUMO energy gap (ΔE) to be 3.59 eV, and the non-covalent interaction (NCI) analysis identified van der Waals interactions and steric repulsion within the molecule. The complex demonstrated potential antimicrobial activity against <em>Escherichia coli, Staphylococcus aureus</em>, and <em>Candida albicans</em>. Additionally, it displayed a moderate anticancer activity against human breast (MCF-7) and lung (A549) carcinoma cell lines. The docking study revealed a binding affinity of −6.05 kcal/mol for EGFR (PDB ID: <span><span>4HJO</span><svg><path></path></svg></span>).</div></div>","PeriodicalId":16414,"journal":{"name":"Journal of Molecular Structure","volume":"1358 ","pages":"Article 145354"},"PeriodicalIF":4.7,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146036337","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 series of butterfly-shaped Yb4 compounds constructed by 8-hydroxyquinoline Schiff base ligands: Structures, NIR luminescence and biological activity","authors":"Ying Shi ,&nbsp;Jie Wang ,&nbsp;Xiao-Yan Xin ,&nbsp;Wen-Min Wang","doi":"10.1016/j.molstruc.2026.145357","DOIUrl":"10.1016/j.molstruc.2026.145357","url":null,"abstract":"<div><div>Four new tetranuclear Yb(III)-based compounds with the formula [Yb₄(L₁)₆(acac)₄(<em>μ</em>₃‐OH)₂] (<strong>1</strong>) (Hacac = acetylacetone, HL₁ = (Z)-5-((4-fluorobenzylidene)amino)quinolin-8-ol), [Yb₄(L₂)₆(acac)₄(<em>μ</em>₃‐OH)₂] (<strong>2</strong>) (HL₂ = (Z)-5-((4-chlorobenzylidene)amino)quinolin-8-ol), [Yb₄(L₃)₆(acac)₄(<em>μ</em>₃‐OH)₂] (<strong>3</strong>) (HL₃ = (Z)-5-((4-bromobenzylidene)amino)quinolin-8-ol), and [Yb₄(L₃)₆(acac)₄(<em>μ</em>₃‐OH)₂] (<strong>4</strong>) (HL₄ = (Z)-5-((4-iodobenzylidene)amino)quinolin-8-ol) have been synthesized via solvothermal method by using four different 8-hydroxyquinoline Schiff base ligands. All the four tetranuclear Yb(III)-based compounds show a butterfly-shaped molecular structure, and the only difference is the coordinated 8-hydroxyquinoline Schiff base ligands. The NIR luminescence properties show that the compounds <strong>1-4</strong> display the characteristic Yb³⁺ luminescence at room temperature. Furthermore, biological activities research reveals that compounds <strong>1</strong>-<strong>4</strong> have greater antibacterial activity than the Schiff base ligands (HL₁, HL₂, HL₃, HL₄) and Yb(acac)₃·2H₂O, and compounds <strong>1</strong>–<strong>4</strong> with DNA interaction are mainly intercalation. What's more, our work suggest that the strong electrondrawing group of Schiff base ligands can enhance the NIR luminescence properties and the antibacterial activity.</div></div>","PeriodicalId":16414,"journal":{"name":"Journal of Molecular Structure","volume":"1358 ","pages":"Article 145357"},"PeriodicalIF":4.7,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146036124","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":"Unprecedented indolylfulgimide linker conjugate with a Negishi-coupled terminal ethylene anchoring group: Synthesis, photochromic performance, and an unexpected acid-promoted formal 1,3-hydrogen shift","authors":"Ziad Moussa ,&nbsp;Abdulrahman A. Alsimaree ,&nbsp;Mustafa S. Alluhaibi ,&nbsp;Aly Abdou ,&nbsp;Munirah M. Al-Rooqi ,&nbsp;Saeed S. Samman ,&nbsp;Abdulaziz M. Almohyawi ,&nbsp;Rabab S. Jassas ,&nbsp;A. Timoumi ,&nbsp;Karola Rück-Braun ,&nbsp;Saleh A. Ahmed","doi":"10.1016/j.molstruc.2026.145336","DOIUrl":"10.1016/j.molstruc.2026.145336","url":null,"abstract":"<div><div>A thermally irreversible indolylfulgimide-based photochromic linker conjugate bearing a terminal ethylene anchoring group was synthesized and fully characterized. A Pd(dba)₂/Q-phos–catalyzed Negishi cross-coupling enabled efficient functionalization of a 6-brominated indolylfulgimide scaffold, followed by controlled acidic deprotection to afford the corresponding carboxylic acid. Under strongly acidic conditions, an unusual rearranged fulgimide was formed via an acid-promoted formal 1,3-hydrogen shift, providing rare experimental insight into rearrangement pathways in indolylfulgimide systems. Density functional theory calculations support the competitive formation of both products and rationalize the rearrangement in terms of closely matched kinetic and thermodynamic pathways. Subsequent coupling with <em>N</em>-dodecenylamine furnished the target linker conjugate in high yield. Photochemical studies in acetonitrile revealed efficient and selective <em>E</em>→<em>C</em> electrocyclization under UV irradiation, clean and quantitative <em>C</em>→<em>E</em> reopening under visible light, and high photochemical robustness under repeated switching conditions. Overall, this work demonstrates a robust synthetic strategy toward a functionalizable indolylfulgimide linker and establishes this system as a promising molecular platform for future surface-anchored and optoelectronic applications.</div></div>","PeriodicalId":16414,"journal":{"name":"Journal of Molecular Structure","volume":"1358 ","pages":"Article 145336"},"PeriodicalIF":4.7,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981128","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":"Recent advances in construction of spiropyrazolones from the ɑ,β-unsaturated pyrazolones","authors":"Jinhua Wan ,&nbsp;Wentian Zeng ,&nbsp;Shen Shan ,&nbsp;Xinlei Fu ,&nbsp;Hanqing Wu ,&nbsp;Kai Yang","doi":"10.1016/j.molstruc.2026.145334","DOIUrl":"10.1016/j.molstruc.2026.145334","url":null,"abstract":"<div><div>Spiropyrazolones are characterized by a spirocyclic structure linked of connected at the 4-position of the pyrazolone core, representing a class of heterocyclic compounds with diverse remarkable biological activities. <em>α,β</em>-Unsaturated pyrazolones have emerged as versatile and powerful synthons for constructing these complex spiro-fused frameworks. This review provides a comprehensive summary of recent advances since 2020 in the synthesis of spiro-fused pyrazolones using <em>α,β</em>-unsaturated pyrazolones. The content is systematically organized based on the ring size and heteroatom composition of the spiro-fused rings, covering the organo- and metal-catalyzed asymmetric synthesis of spiropyrazolones fused with five-, six- and three-membered ring, along with discussions of some reaction mechanisms.</div></div>","PeriodicalId":16414,"journal":{"name":"Journal of Molecular Structure","volume":"1358 ","pages":"Article 145334"},"PeriodicalIF":4.7,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981238","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}