The Journal of Physical Chemistry A最新文献

{"title":"Investigation of Medium-Sized Methane Clusters with Quantum Chemical First-Principles and Ab Initio Calculations","authors":"Xiaoyan Cao,&nbsp;Michael Dolg","doi":"10.1021/acs.jpca.6c05287","DOIUrl":"https://doi.org/10.1021/acs.jpca.6c05287","url":null,"abstract":"<p>The structures and relative stabilities of medium-sizedmethaneclusters (CH₄)_<em>n</em> (<em>n</em> = 10–40) have been studied using first-principles densityfunctional theory calculations applying the Becke and Lee, Yang, Parrhybrid functional with <em>a posteriori</em> pairwise correctionsfor dispersion interactions due to Grimme, B3LYP+D3+BJ, and basissets of doubly polarized valence triple-ζ quality. For all structures,vibrational frequencies were evaluated. Coupled-cluster single-pointcalculations including single, double, and perturbative triple substitutionswith an explicit dependence on the interelectronic distance, CCSD(T)-F12,were performed using the incremental scheme accounting for up to third-orderinteractions between the monomers, applying correlation-consistentbasis sets of polarized double- and triple-ζ quality especiallyoptimized for F12 calculations. The structures obtained with the B3LYP+D3+BJapproach were found to have a higher stability than those of threesets published previously in the literature, which are based on pairwiseadditive potentials or density-functional calculations corrected fordispersion interactions by atom-centered potentials. By means of extrapolation,the heat of vaporization was estimated as 6.87 ± 0.16 kJ/moland 6.97 ± 0.19 kJ/mol at the B3LYP+D3+BJ and CCSD(T)-F12 levels,respectively (exp. 8.19 kJ/mol). The rotation of CH₄ monomerswas studied at the B3LYP+D3+BJ and CCSD(T)-F12 level and was foundto have barriers of only about 1.2–1.5 and 3.2–3.7 kJ/molfor monomers at the surface and in the center of a (CH₄)₃₀ cluster, respectively. The incremental CCSD(T)-F12calculations exhibit a scaling better than <em>O</em>(<em>n</em>²) for clusters up to (CH₄)₄₀ comprising 5000 contracted basis functions, whereas simulationsfor larger clusters exhibit a linear size dependence.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"130 40","pages":"7966–7977"},"PeriodicalIF":3.0,"publicationDate":"2026-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149124758","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":"Coverage- and Isotope-Dependent Langmuir–Rideal/Eley–Rideal and Hot-Atom Reaction Dynamics of H(D) with D(H)-Covered Pt(100): Quasiclassical Molecular Dynamics Simulations","authors":"Can Doğan Vurdu","doi":"10.1021/acs.jpca.6c04522","DOIUrl":"https://doi.org/10.1021/acs.jpca.6c04522","url":null,"abstract":"<p>Hydrogen-isotope abstraction on platinum surfaces isa key elementaryprocess in heterogeneous catalysis and hydrogen-related surface chemistry.In this work, coverage- and isotope-dependent reaction dynamics ofH or D atoms impinging on D- or H-covered Pt(100) surfaces were investigatedusing quasiclassical molecular dynamics simulations with a flexiblePt slab at a fixed low incidence energy of 0.07 eV. The adsorbatecoverage was varied from 0.18 to 0.80 monolayers (ML). Hydrogen isotope–Ptinteractions were described using an adjusted London–Eyring–Polanyi–Satopotential, whereas the Pt substrate was represented by a many-bodyembedded-atom potential, enabling explicit lattice motion and energytransfer. Five outcome channels were quantified: HD formation, H₂/D₂ formation, surface sticking, below-top-layerpenetration, and inelastic scattering. HD formation was the dominantreactive pathway and increased monotonically with coverage, whereasthe total nonreactive probability decreased as the adsorbate layerbecame denser. Early HD products were associated with Langmuir–Rideal/Eley–Ridealand short-time hot-atom pathways, whereas delayed HD formation andH₂/D₂ production proceeded through longer-timehot-atom motion. Below-top-layer penetration was consistently moreprobable than surface sticking. D-on-H collisions produced higherHD probabilities than H-on-D collisions; this ordering is interpretedas an integrated isotope-dependent trajectory effect involving projectilemomentum and speed, dynamical steering, adsorbate zero-point energies,and energy exchange with the adsorbate layer and Pt lattice. All conclusionsare restricted to the explicitly simulated 0.18–0.80 ML intervsal.These results provide a surface-specific picture of how coverage,isotope mass, lattice flexibility, and near-surface accessibilityjointly control low-energy hydrogen-isotope abstraction dynamics onPt(100).</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"130 40","pages":"7928–7941"},"PeriodicalIF":3.0,"publicationDate":"2026-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149130624","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":"Perturbatively Corrected Linear Response Selected Configuration Interaction","authors":"Peter Reinholdt,&nbsp;Erik Rosendahl Kjellgren,&nbsp;Jacob Kongsted","doi":"10.1021/acs.jpca.6c04532","DOIUrl":"https://doi.org/10.1021/acs.jpca.6c04532","url":null,"abstract":"<p>Selectedconfiguration interaction (SCI) methods have emerged aspowerful, lower-cost alternatives to full configuration interaction(FCI) for ground- and excited-state energies. Still, calculating molecularresponse properties with the SCI remains a significant challenge.In this work, we introduce perturbative corrections to the linearresponse selected configuration interaction (LR-SCI) framework, usingan order-by-order Epstein–Nesbet perturbation expansion throughsecond order. We demonstrate that in this theoretical framework, thefinite-order perturbative treatment preserves the pole structure ofthe parent variational LR-SCI theory, which means that although themethod can be useful for static properties, it is not suitable forfrequency-dependent molecular response properties. Numerical benchmarkstargeting the static polarizabilities of water, ethene, boron hydride,and hydrogen chloride demonstrate systematic convergence toward theFCI limit for both the ground and excited electronic states. Whilefirst-order corrections yield marginal improvements, the inclusionof second-order corrections substantially enhances accuracy over underlyingvariational treatments and diminishes the oscillatory convergencebehavior present in the parent variational LR-SCI method. Combinedwith extrapolation techniques, LR-SCI-PT achieves excellent agreementwith high-level coupled-cluster references, establishing a powerfulroute toward near-FCI-quality molecular properties for systems otherwiseinaccessible to exact FCI treatments.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"130 40","pages":"8044–8054"},"PeriodicalIF":3.0,"publicationDate":"2026-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149124887","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 Photoionization Spectrum of the Acetyl Radical and the Kinetics of Its Unimolecular and Bimolecular Reactions at Elevated Pressures","authors":"Jaeyoung Cho,&nbsp;Raghu Sivaramakrishnan,&nbsp;Leonid Sheps","doi":"10.1021/acs.jpca.6c05086","DOIUrl":"https://doi.org/10.1021/acs.jpca.6c05086","url":null,"abstract":"<p>The acetyl radical (CH₃CO) is a primary intermediateduring the oxidation and combustion of CH₃CHO and representsa prototypical example of a weakly bound acyl radical. However, itis challenging to detect and has rarely been probed at elevated pressures,where CH₃CO decays by competing bimolecular and unimolecularreactions. The present study provides a combined modeling and experimentalanalysis of the comprehensive network of CH₃CO unimolecularand bimolecular kinetics at 500 kPa and 300–366 K. CH₃CO was generated by acetaldehyde (CH₃CHO) + Cl reactions,where the Cl is produced by pulsed laser photolysis of oxalyl chloride((COCl)₂) at 248 nm. The progress of reactions was monitoredvia multiplexed photoionization mass spectrometry, providing concentration–timeprofiles of CH₃CHO, CH₃CO, methyl (CH₃), ketene (CH₂CO), acetone (CH₃COCH₃), and biacetyl ((CH₃CO)₂). The concentrationof CH₃CO was quantified from time-resolved atom balanceanalysis. The absolute photoionization spectrum of CH₃COwas determined for the first time up to energies of 11 eV, enablingfuture quantitative measurements in more complex environments. Theexperimental data were simulated using a kinetic model consistingof unimolecular and bimolecular reactions driving CH₃COformation and decay as well as relevant secondary reactions describingthe evolution of the observed intermediates. The measured time profilesshowed strong sensitivity to the following reactions involving CH₃CO: (R1) CH₃CO = CH₃ + CO, (R2a) CH₃CO + CH₃CO = (CH₃CO)₂, (R3a)CH₃CO + CH₃ = CH₃COCH₃, and (R5) CH₃CO + Cl = CH₂CO + HCl. The best-fitbimolecular reaction rate coefficients (<em>k</em>_2a, <em>k</em>_3a, and <em>k</em>₅) differ from the literature values by up to a factor of 2, mostlikely because the prior works studied each reaction separately, ratherthan in one unified experimental campaign, and were influenced byother competing reactions. Simulations using the assembled kineticmodel enable a direct determination of the rate coefficient of (R1),which is fit to the Arrhenius expression, <em>k</em>₁ = 7.63 × 10¹⁰ exp(−6868/<em>T</em>) s^–1 (336–366 K, 500 kPa, He buffer, anduncertainty of ±40%). The present study extends the previouslyavailable data on CH₃CO dissociation to much higher pressuresand provides improved constraints for collisional energy transferparameters and activation energies from theoretical kinetics studies.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"130 39","pages":"7862–7873"},"PeriodicalIF":3.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149093674","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":"Interface Specific SN2 Reactions of Gemini Diammonium Ions","authors":"Theis I. Solling,&nbsp;Martin P. Andersson,&nbsp;J. L. Beauchamp","doi":"10.1021/acs.jpca.6c03272","DOIUrl":"https://doi.org/10.1021/acs.jpca.6c03272","url":null,"abstract":"<p>This study demonstrates a unique interface-specific S_N2 reaction of the gemini surfactant decamethonium bromideat theair–water boundary. Using electrospray and field-induced dropletionization mass spectrometry combined with DFT and COSMO-RS modeling,we show that interfacial charge alignment induces combination of twodiammonium ions via water to yield an ether dimer. The reaction isabsent in bulk solution and is strongly enhanced at the interfacedue to stabilization of a bent, Br^–-pinned conformer.Computational results confirm reduced activation barriers and amphiphilicorientation driving interfacial reactivity, offering insight intocharge-directed chemistry at liquid interfaces and new routes forcontrolled synthesis.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"130 39","pages":"7773–7782"},"PeriodicalIF":3.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149093638","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":"Structure of Furan from 44 Isotopologues─Resolving Differences in the Theoretical (re) and Semi-Experimental Equilibrium (reSE) Structures","authors":"Kolton T. Mehalko,&nbsp;Brian J. Esselman,&nbsp;Peter R. Franke,&nbsp;Martin S. Holdren,&nbsp;Gabi Wenzel,&nbsp;D. Archie Stewart,&nbsp;Zachary P. Burke,&nbsp;Brett A. McGuire,&nbsp;R. Claude Woods,&nbsp;Robert J. McMahon","doi":"10.1021/acs.jpca.6c04036","DOIUrl":"https://doi.org/10.1021/acs.jpca.6c04036","url":null,"abstract":"<p>The rotational spectra of furan and numerous isotopologueswererecorded and analyzed between 6 and 750 GHz. High-temperature, high-pressure,base-catalyzed H/D exchange was employed to create a mixture of allpossible furan-<em>d</em>_<em>x</em> isotopologues,allowing for the measurement and analysis of the rotational spectraof 44 furan isotopologues. The experimental rotational constants ofthese isotopologues, combined with CCSD(T)/cc-pCVTZ corrections forthe effects of vibration–rotation interaction and the electron-massdistribution, were used to determine a semi-experimental equilibrium(<em>r</em>_<em>e</em>^SE) structureof furan. The large number of isotopologues used, including 35 isotopologuesobserved for the first time, allowed for the determination of the <em>r</em>_<em>e</em>^SE structure toa high level of accuracy and precision (≤0.0003 Å uncertaintiesin bond distances and ≤0.02° in bond angles). The currentstudy additionally corrects for differences in principal axis rotationbetween the structure at which the vibration–rotation interactionconstants were evaluated (CCSD(T)/cc-pCVTZ) and the <em>r</em>_<em>e</em>^SE structure. The differencein rotation between these two structures had been previously reported,but not addressed. The “best theoretical estimate” (BTE)for the structure of furan was determined using a CCSD(T)/cc-pCV5Zgeometry, with additional corrections addressing finite basis set,higher-level electron correlation, and relativistic effects, as wellas the diagonal Born–Oppenheimer correction. The BTE structureof furan is compared to the <em>r</em>_<em>e</em>^SE structure of furan, which is also compared tothe previously determined <em>r</em>_<em>e</em>^SE structure of its sulfur-containing analogue,thiophene.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"130 39","pages":"7783–7800"},"PeriodicalIF":3.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149093645","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":"Direct C2 Bottom-Up Assembly: Unraveling the Formation Mechanism of [10,0] Metallofullertubes, Ce2@C40+40+20n Series","authors":"Kexin Ma,&nbsp;Dongyu Liu,&nbsp;Kai Tan,&nbsp;Anan Wu,&nbsp;Taishan Wang,&nbsp;Xin Lu","doi":"10.1021/acs.jpca.6c04305","DOIUrl":"https://doi.org/10.1021/acs.jpca.6c04305","url":null,"abstract":"<p>The preparation of metallofullertubes remains challenging,andelucidating the atomistic details of their formation is critical forachieving controlled synthesis. Inspired by recent experimental advances(Angew. Chem. Int. Ed. 2022, 61, e202116854), we present a densityfunctional theory (DFT) investigation into the origin of Ce₂@<em>D₅</em>(450)-C₁₀₀ derived fromthe experimentally characterized Ce₂@<em>I</em>_<em>h</em>(7)-C₈₀ and Ce₂@<em>D</em>_<em>5h</em>(6)-C₈₀ structures. We uncover a distinct growth pathway in which additionalC₂₀ rings form through ten consecutive C₂ insertions,notably without invoking Stone–Wales rearrangements. Moreover,our theoretical studies summarize the [10,0] metallofullertube Ce₂@C_40+40+20n series and predict several unreportedstable isomers of [10,0] metallofullertubes, such as Ce₂@<em>D</em>_<em>5d</em>(10765)-C₁₂₀ and Ce₂@<em>D</em>_<em>5h</em>(10766)-C₁₂₀. These findings provide fundamental mechanisticinsights into metallofullertube assembly and establish guiding principlesfor the rational design of next-generation nanomaterials.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"130 39","pages":"7801–7811"},"PeriodicalIF":3.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149124880","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 Effect of Single-Atom (Zn, Cd, or Hg) Replacement on the Strength and Directionality of the Spodium Bond","authors":"Atash V. Gurbanov,&nbsp;Rosa M Gomila,&nbsp;Fatali E. Huseynov,&nbsp;Antonio Frontera,&nbsp;Kamran T. Mahmudov","doi":"10.1021/acs.jpca.6c05244","DOIUrl":"https://doi.org/10.1021/acs.jpca.6c05244","url":null,"abstract":"<p>The spodium bond (SpB) is an attractive noncovalent interactionbetween the Group 12 element (Zn, Cd, or Hg) and a nucleophile (Nu).In comparison to the monovariant H-bond at R–H<strong>···</strong>Nu synthon, the SpB parameters (strength and directionality) canalso be regulated by replacement of a single spodium atom (Sp = Zn,Cd, or Hg) at R–Sp<strong>···</strong>Nu. In thiswork we examined the effect of a single spodium atom replacement strategyon the strength and directionality of inter- or intramolecular SpBin a series of coordination and supramolecular compounds obtainedfrom the Cambridge Structural Database. Due to their d-orbitals, Group12 elements commonly act as π-hole donors, and there is no cleartrend between the strength of Sp<strong>···</strong>Nuinteractions and either the atomic polarizability or the van der Waalsradius of the Sp atom. Complementary density functional theory calculationsemploying QTAIM and natural bond orbital analysis reveal that thebonding character of spodium interactions transitions from coordination-likeinteractions in Cd complexes to genuine noncovalent bonds in Hg systems,with the σ-hole mechanism serving as the primary stabilizationdriver.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"130 39","pages":"7822–7831"},"PeriodicalIF":3.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149093547","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":"Computational Prediction of Pressure-Responsive Luminescence of a D-π-A Compound with Boron–Nitrogen Motifs","authors":"Lin Zhang,&nbsp;Xiaochuan Liu,&nbsp;Zhixin Ren,&nbsp;Xiao-Wu Lei,&nbsp;Zexing Cao","doi":"10.1021/acs.jpca.6c05292","DOIUrl":"https://doi.org/10.1021/acs.jpca.6c05292","url":null,"abstract":"<p>Under pressure, organic luminescent materials typicallydisplaypeculiar and fascinating photoluminescence behaviors. Elucidatingthe luminescence mechanism under pressure is the key to the rationaldesign of piezochromic materials. Here, we carried out an in-depththeoretical investigation of the pressure-responsive behaviors ofa highly twisted donor-π-acceptor (D-π-A)-type organoboroncompound (FMesB-Cz) by combining dispersion-corrected density functionaltheory (DFT-D) crystalline-structure simulations, hybrid quantum mechanics/molecularmechanics (QM/MM) calculations, and thermal vibration correlationfunction formalism. The results reveal that external pressure efficientlysuppresses nonradiative decay channels, further elevating its fluorescencequantum yield and producing a moderate pressure-induced emission enhancement(PIEE) effect. Upon compressive loading, FMesB-Cz crystals displaydistinctive spectral behavior: the absorption band undergoes a redshift,whereas the emission band is blue-shifted, along with intensifiedvibrational features and disrupted spectral symmetry. Aggregation-inducedblue-shifted emission (AIBSE) represents an intriguing photoluminescencephenomenon. An in-depth understanding of its intrinsic mechanism isessential for the development of novel high-performance stimuli-responsiveluminescent materials. Through systematic investigation and interpretationof the pressure-dependent luminescent properties of the FMesB-Cz compound,this work uncovers the underlying structure–property relationshipin stimuli-responsive systems and offers theoretical guidance forthe rational design of pressure-sensitive opto<strong>e</strong>lectronicfunctional materials.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"130 39","pages":"7832–7843"},"PeriodicalIF":3.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149093558","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":"Topology-Controlled Photophysics of Ionized C14H10 Isomers","authors":"Anna Maria Reider,&nbsp;Miriam Kappe,&nbsp;Paul Martini,&nbsp;Martin Schmidt,&nbsp;Serge A. Krasnokutski,&nbsp;Paul Scheier","doi":"10.1021/acs.jpca.6c04463","DOIUrl":"https://doi.org/10.1021/acs.jpca.6c04463","url":null,"abstract":"<p>The optical signaturesof polycyclic aromatic hydrocarbons (PAHs)are highly sensitive to their molecular geometry, charge state, andintermolecular interactions. A comparison between the linear anthraceneand angular phenanthrene ions highlights how topological effects governthe degree of electronic delocalization in the excited state, resultingin spectroscopic signatures of vibronic coupling, varying oscillatorstrengths, and nonradiative relaxation pathways. This work presentsthe UV–vis spectra of the cationic, protonated, and anionicC₁₄H₁₀ isomers utilizing He-tagging action spectroscopyvia helium nanodroplet isolation. The linear anthracene cations retaina well-resolved vibronic structure, characteristic of delocalizedπ-systems, whereas the angular phenanthrene cation producesbroader bands typical of enhanced vibronic coupling and a more localizedcharge distribution. Hydrogenation disrupts conjugation and quenchesthe vibronic progression most strongly in anthracene. Notably, thebroad, weakly structured spectrum of protonated phenanthrene is consistentwith the pronounced excited-state twisting predicted by previous calculations.Anionic C₁₄H₁₀, on the other hand, displaysweak continua, aligning with low oscillator strengths and rapid autodetachment.Dimerization generally broadens and weakens the absorption features,particularly for phenanthrene, consistent with the coexistence ofseveral low-lying π-stacked isomers and enhanced vibronic coupling.Comparison with matrix isolation and gas-phase spectra supports thehigh fidelity of the helium nanodroplet approach.</p>","PeriodicalId":59,"journal":{"name":"The Journal of Physical Chemistry A","volume":"130 39","pages":"7812–7821"},"PeriodicalIF":3.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149093545","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}