{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,22]],"date-time":"2026-10-22T12:47:56Z","timestamp":1792673276577,"version":"4.5.0"},"reference-count":45,"publisher":"American Chemical Society (ACS)","issue":"42","license":[{"start":{"date-parts":[[2026,10,7]],"date-time":"2026-10-07T00:00:00Z","timestamp":1791331200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100006769","name":"Russian Science Foundation","doi-asserted-by":"publisher","award":["25-43-02210"],"award-info":[{"award-number":["25-43-02210"]}],"id":[{"id":"10.13039\/501100006769","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["12325406"],"award-info":[{"award-number":["12325406"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["92261201"],"award-info":[{"award-number":["92261201"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["W2512072"],"award-info":[{"award-number":["W2512072"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100007128","name":"Natural Science Foundation of Shaanxi Province","doi-asserted-by":"publisher","award":["2023JC-XJ-03"],"award-info":[{"award-number":["2023JC-XJ-03"]}],"id":[{"id":"10.13039\/501100007128","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,10,22]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Hydration critically reshapes ultrafast electronic relaxation in biorelevant molecules, yet its mechanistic role remains poorly understood. Here, we investigate intermolecular Coulombic decay (ICD) following medium-energy (E0 = 103 eV) electron impact ionization of hydrated pyridine, a prototypical nucleobase analogue. Combining multiparticle momentum coincidence spectroscopy with high-level electronic structure calculations, we identify water-initiated ICD and find evidence consistent with an additional pyridine-initiated ICD pathway, in which inner-valence ionization leads to ionization of the neighboring molecule. Water vacancies decay exclusively via the ICD, establishing a highly efficient direct channel. In contrast, pyridine vacancies compete with Auger decay, reducing the efficiency of the pyridine-to-water ICD pathway. As in pyridine dimers, heterocycle-initiated ICD is dominated by N 2s vacancy states. Our results reveal a dual role of water: it opens a highly efficient direct ICD pathway via O 2s vacancy states and acts as an energy-accepting partner following biomolecular inner-valence ionization. These results reveal how microsolvation governs ultrafast relaxation and shapes radiation-induced damage pathways in DNA-related systems.<\/jats:p>","DOI":"10.1021\/acs.jpca.6c05980","type":"journal-article","created":{"date-parts":[[2026,10,7]],"date-time":"2026-10-07T09:01:33Z","timestamp":1791363693000},"page":"8385-8393","source":"Crossref","is-referenced-by-count":0,"title":["Microsolvation Controls Ultrafast Relaxation Pathways\nin Hydrated Pyridine"],"prefix":"10.1021","volume":"130","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2949-2286","authenticated-orcid":true,"given":"Deepthy","family":"Maria Mootheril","sequence":"first","affiliation":[{"name":"Max-Planck-Institut Fu\u0308r Kernphysik , Saupfercheckweg 1 , ,","place":["Heidelberg, Germany, 69117"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9328-1598","authenticated-orcid":true,"given":"Anna D.","family":"Skitnevskaya","sequence":"additional","affiliation":[{"name":"A.E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences , , ,","place":["Irkutsk, Russia, 664033"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6132-092X","authenticated-orcid":true,"given":"Xueguang","family":"Ren","sequence":"additional","affiliation":[{"name":"Xi\u2019an Jiaotong University , , ,","place":["Xi\u2019an, China, 710049"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2583-4370","authenticated-orcid":true,"given":"Alexander I.","family":"Kuleff","sequence":"additional","affiliation":[{"name":"Universita\u0308t Heidelberg , , ,","place":["Heidelberg, Germany, 69120"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alexander B.","family":"Trofimov","sequence":"additional","affiliation":[{"name":"A.E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences , , ,","place":["Irkutsk, Russia, 664033"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4598-0650","authenticated-orcid":true,"given":"Lorenz S.","family":"Cederbaum","sequence":"additional","affiliation":[{"name":"Universita\u0308t Heidelberg , , ,","place":["Heidelberg, Germany, 69120"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5312-3747","authenticated-orcid":true,"given":"Thomas","family":"Pfeifer","sequence":"additional","affiliation":[{"name":"Max-Planck-Institut Fu\u0308r Kernphysik , Saupfercheckweg 1 , ,","place":["Heidelberg, Germany, 69117"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alexander","family":"Dorn","sequence":"additional","affiliation":[{"name":"Max-Planck-Institut Fu\u0308r Kernphysik , Saupfercheckweg 1 , ,","place":["Heidelberg, Germany, 69117"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"316","published-online":{"date-parts":[[2026,10,7]]},"reference":[{"key":"2026102208070004100_cit1","doi-asserted-by":"publisher","first-page":"1658","DOI":"10.1126\/science.287.5458.1658","article-title":"Resonant Formation\nof DNA Strand Breaks by Low-Energy (3 to 20 eV) Electrons","volume":"287","author":"Boudai\u0308ffa","year":"2000","journal-title":"Science"},{"key":"2026102208070004100_cit2","doi-asserted-by":"publisher","first-page":"9329","DOI":"10.1039\/D4CP03907F","article-title":"Interplay of protection\nand damage through intermolecular processes in the decay of electronic\ncore holes in microsolvated organic molecules","volume":"27","author":"Blo\u00df","year":"2025","journal-title":"Phys. Chem. Chem. Phys."},{"key":"2026102208070004100_cit3","doi-asserted-by":"publisher","first-page":"10694","DOI":"10.1021\/acs.chemrev.6b00765","article-title":"Water Dynamics in the Hydration Shells\nof Biomolecules","volume":"117","author":"Laage","year":"2017","journal-title":"Chem. Rev."},{"key":"2026102208070004100_cit4","doi-asserted-by":"publisher","first-page":"4778","DOI":"10.1103\/PhysRevLett.79.4778","article-title":"Giant intermolecular\ndecay and fragmentation\nof clusters","volume":"79","author":"Cederbaum","year":"1997","journal-title":"Phys. Rev. Lett."},{"key":"2026102208070004100_cit5","doi-asserted-by":"publisher","first-page":"11295","DOI":"10.1021\/acs.chemrev.0c00106","article-title":"Interatomic and Intermolecular\nCoulombic Decay","volume":"120","author":"Jahnke","year":"2020","journal-title":"Chem. Rev."},{"key":"2026102208070004100_cit6","doi-asserted-by":"publisher","first-page":"1418","DOI":"10.1021\/acs.jpclett.2c03654","article-title":"Two-Sided\nImpact of Water on the\nRelaxation of Inner-Valence Vacancies of Biologically Relevant Molecules","volume":"14","author":"Skitnevskaya","year":"2023","journal-title":"J. Phys. Chem. Lett."},{"key":"2026102208070004100_cit7","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevLett.128.133001","article-title":"Intermolecular Coulombic Decay in Liquid Water","volume":"128","author":"Zhang","year":"2022","journal-title":"Phys. Rev. Lett."},{"key":"2026102208070004100_cit8","doi-asserted-by":"publisher","DOI":"10.1038\/s41467-018-07501-6","article-title":"Competition\nbetween proton transfer and intermolecular Coulombic decay in water","volume":"9","author":"Richter","year":"2018","journal-title":"Nat. Commun."},{"key":"2026102208070004100_cit9","doi-asserted-by":"publisher","first-page":"1062","DOI":"10.1038\/s41567-018-0214-9","article-title":"Experimental evidence\nfor ultrafast intermolecular relaxation processes\nin hydrated biomolecules","volume":"14","author":"Ren","year":"2018","journal-title":"Nat. Phys."},{"key":"2026102208070004100_cit10","doi-asserted-by":"publisher","first-page":"7146","DOI":"10.1021\/acs.jpclett.1c01879","article-title":"Suppression of X-ray-Induced Radiation\nDamage to Biomolecules in\nAqueous Environments by Immediate Intermolecular Decay of Inner-Shell\nVacancies","volume":"12","author":"Hans","year":"2021","journal-title":"J. Phys. Chem. Lett."},{"key":"2026102208070004100_cit11","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevX.15.011053","article-title":"Damaging Intermolecular\nRelaxation Processes Initiated by Heavy-Ion Irradiation of Hydrated\nBiomolecules","volume":"15","author":"Gao","year":"2025","journal-title":"Phys. Rev. X"},{"key":"2026102208070004100_cit12","doi-asserted-by":"publisher","first-page":"1529","DOI":"10.1021\/acs.jpclett.3c02979","article-title":"Revealing\nthe Role of N Heteroatoms in Noncovalent Aromatic Interactions by\nUltrafast Intermolecular Coulombic Decay","volume":"15","author":"Zhou","year":"2024","journal-title":"J.\nPhys. Chem. Lett."},{"key":"2026102208070004100_cit13","doi-asserted-by":"publisher","first-page":"1463","DOI":"10.1088\/0034-4885\/66\/9\/203","article-title":"Recoil-ion and electron\nmomentum spectroscopy: reaction-microscopes","volume":"66","author":"Ullrich","year":"2003","journal-title":"Rep. Prog. Phys."},{"key":"2026102208070004100_cit14","doi-asserted-by":"publisher","DOI":"10.1038\/ncomms11093","article-title":"Direct evidence of\ntwo interatomic relaxation mechanisms in argon dimers ionized by electron\nimpact","volume":"7","author":"Ren","year":"2016","journal-title":"Nat. Commun."},{"key":"2026102208070004100_cit15","doi-asserted-by":"publisher","first-page":"510","DOI":"10.1021\/je60047a015","article-title":"Vapor pressure of deuterated water from 106 to 300.deg","volume":"15","author":"Liu","year":"1970","journal-title":"J. Chem. Eng. Data"},{"key":"2026102208070004100_cit16","doi-asserted-by":"publisher","first-page":"4289","DOI":"10.1021\/ja01573a014","article-title":"Pyridine: Experimental and Calculated\nChemical Thermodynamic Properties between 0 and 1500 K.; a Revised\nVibrational Assignment","volume":"79","author":"McCullough","year":"1957","journal-title":"J. Am. Chem. Soc."},{"key":"2026102208070004100_cit17","unstructured":"Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheese man, J. R.; Scalmani, G.; Barone, V.; Petersson, G. A.; Nakatsuji, H.; Li, X.; Caricato, M.; Marenich, A. V.; Bloino, J.; Janesko, B. G.; Gomperts, R.; Mennucci, B.; Hratchian, H. P.; Ortiz, J. V.; Izmaylov, A. F.; Sonnenberg, J. L.; Williams-Young, D.; Ding, F.; Lipparini, F.; Egidi, F.; Goings, J.; Peng, B.; Petrone, A.; Henderson, T.; Ranasinghe, D.; Zakrzewski, V. G.; Gao, J.; Rega, N.; Zheng, G.; Liang, W.; Hada, M.; Ehara, M.; Toyota, K.; Fukuda, R.; Hasegawa, J.; Ishida, M.; Nakajima, T.; Honda, Y.; Kitao, O.; Nakai, H.; Vreven, T.; Throssell, K.; Montgomery, J. A.; Peralta, J. E.; Ogliaro, F.; Bearpark, M. J.\n          Gaussian\nInc 16 Revision C.01; Gaussian Inc: Wallingford CT, 2016."},{"key":"2026102208070004100_cit18","doi-asserted-by":"publisher","first-page":"14073","DOI":"10.1039\/C8CP07015F","article-title":"Photoinduced electron-driven\nproton transfer from water to an N-heterocyclic chromophore: nonadiabatic\ndynamics studies for pyridine-water clusters","volume":"21","author":"Pang","year":"2019","journal-title":"Phys. Chem. Chem. Phys."},{"key":"2026102208070004100_cit19","doi-asserted-by":"publisher","first-page":"855","DOI":"10.1021\/acs.jpca.6b11255","article-title":"Multidimensional\nLarge Amplitude Dynamics in the Pyridine-Water Complex","volume":"121","author":"Mackenzie","year":"2017","journal-title":"J. Phys. Chem. A"},{"key":"2026102208070004100_cit20","doi-asserted-by":"publisher","first-page":"57","DOI":"10.1016\/0167-7977(84)90002-9","article-title":"Computational\nmethods for the one-particle green\u2019s function","volume":"1","author":"von Niessen","year":"1984","journal-title":"Comput. Phys. Rep."},{"key":"2026102208070004100_cit21","doi-asserted-by":"publisher","first-page":"267","DOI":"10.1007\/BF01438358","article-title":"Higher-order approximations for the\nparticle-particle propagator","volume":"317","author":"Schirmer","year":"1984","journal-title":"Z. Phys. A Atoms\nNuclei"},{"key":"2026102208070004100_cit22","doi-asserted-by":"publisher","first-page":"11","DOI":"10.1016\/j.chemphys.2006.07.001","article-title":"The calculation\nof molecular double ionization spectra by Green\u2019s functions","volume":"329","author":"Tarantelli","year":"2006","journal-title":"Chem. Phys."},{"key":"2026102208070004100_cit23","doi-asserted-by":"publisher","first-page":"6195","DOI":"10.1063\/1.457438","article-title":"A band-Lanczos method\nfor computing matrix elements of a resolvent","volume":"91","author":"Meyer","year":"1989","journal-title":"J. Chem. Phys."},{"key":"2026102208070004100_cit24","doi-asserted-by":"publisher","first-page":"7122","DOI":"10.1063\/1.471429","article-title":"Block Lanczos\nand many-body theory: Application to the one-particle Green\u2019s\nfunction","volume":"104","author":"Weikert","year":"1996","journal-title":"J. Chem. Phys."},{"key":"2026102208070004100_cit25","doi-asserted-by":"publisher","first-page":"115","DOI":"10.1002\/9780470142899.ch3","article-title":"Correlation effects\nin the ionization of molecules: breakdown of the molecular orbital\npicture","volume":"65","author":"Cederbaum","year":"1986","journal-title":"Adv. Chem. Phys."},{"key":"2026102208070004100_cit26","doi-asserted-by":"publisher","first-page":"523","DOI":"10.1063\/1.460369","article-title":"Many dicationic states and two-hole\npopulation analysis as a bridge to Auger spectra: Strong localization\nphenomena in BF3","volume":"94","author":"Tarantelli","year":"1991","journal-title":"J. Chem. Phys."},{"key":"2026102208070004100_cit27","doi-asserted-by":"publisher","first-page":"49","DOI":"10.1016\/j.chemphys.2007.03.016","article-title":"Double photoionisation\nspectra of small molecules and a new empirical rule for double ionisation\nenergies","volume":"335","author":"Molloy","year":"2007","journal-title":"Chem. Phys."},{"key":"2026102208070004100_cit28","doi-asserted-by":"publisher","first-page":"467","DOI":"10.1016\/0301-0104(93)85173-6","article-title":"Triplet-state energies\nof H2O2+: a combined experimental and theoretical\nstudy","volume":"175","author":"Severs","year":"1993","journal-title":"Chem. Phys."},{"key":"2026102208070004100_cit29","doi-asserted-by":"publisher","DOI":"10.1063\/1.4986405","article-title":"Ionization\nof pyridine: Interplay of orbital relaxation and electron correlation","volume":"146","author":"Trofimov","year":"2017","journal-title":"J. Chem. Phys."},{"key":"2026102208070004100_cit30","doi-asserted-by":"publisher","first-page":"183","DOI":"10.1016\/j.chemphys.2008.12.009","article-title":"Threshold photoelectron\nspectroscopy of H2O and D2O over the photon\nenergy range 12\u201340 eV","volume":"355","author":"Truong","year":"2009","journal-title":"Chem. Phys."},{"key":"2026102208070004100_cit31","doi-asserted-by":"publisher","DOI":"10.1063\/1.5137794","article-title":"Intermediate\nstate representation approach to physical properties of molecular\nelectron-detached states. II. Benchmarking","volume":"152","author":"Dempwolff","year":"2020","journal-title":"J. Chem. Phys."},{"key":"2026102208070004100_cit32","doi-asserted-by":"publisher","first-page":"1101","DOI":"10.1007\/s10593-008-0159-5","article-title":"Theoretical\ninvestigation of photoelectron spectra of furan, pyrrole, thiophene,\nand selenole","volume":"44","author":"Trofimov","year":"2008","journal-title":"Chem. Heterocycl. Compd."},{"key":"2026102208070004100_cit33","doi-asserted-by":"publisher","DOI":"10.1063\/1.2357921","article-title":"Ionization\nand double ionization of small water clusters","volume":"125","author":"Mu\u0308ller","year":"2006","journal-title":"J. Chem. Phys."},{"key":"2026102208070004100_cit34","doi-asserted-by":"publisher","first-page":"6817","DOI":"10.1021\/ja200963y","article-title":"Intermolecular\nCoulombic Decay in\nSmall Biochemically Relevant Hydrogen-Bonded Systems","volume":"133","author":"Stoychev","year":"2011","journal-title":"J. Am. Chem. Soc."},{"key":"2026102208070004100_cit35","doi-asserted-by":"publisher","first-page":"45","DOI":"10.1021\/acs.jpca.6b09501","article-title":"Probing Conformers of Benzene Dimer\nwith Intermolecular Coulombic Decay Spectroscopy","volume":"121","author":"Sisourat","year":"2017","journal-title":"J. Phys. Chem. A"},{"key":"2026102208070004100_cit36","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevA.108.052814","article-title":"Ultrafast molecular dissociation induced by intermolecular\nCoulombic decay in water clusters","volume":"108","author":"Ren","year":"2023","journal-title":"Phys. Rev.\nA"},{"key":"2026102208070004100_cit37","doi-asserted-by":"publisher","DOI":"10.1038\/s42004-025-01547-6","article-title":"Enhanced intermolecular\nCoulombic decay due to sulfur heteroatoms in thiophene dimer","volume":"8","author":"Mootheril","year":"2025","journal-title":"Commun. Chem."},{"key":"2026102208070004100_cit38","doi-asserted-by":"publisher","first-page":"1006","DOI":"10.1002\/cphc.201000034","article-title":"Generation\nof Highly Damaging H2O+\nRadicals by Inner Valence Shell Ionization of Water","volume":"11","author":"Vendrell","year":"2010","journal-title":"ChemPhysChem"},{"key":"2026102208070004100_cit39","doi-asserted-by":"publisher","DOI":"10.1063\/1.5055593","article-title":"Dissociations\nof water ions after valence and inner-valence ionization","volume":"149","author":"Roos","year":"2018","journal-title":"J. Chem. Phys."},{"key":"2026102208070004100_cit40","doi-asserted-by":"publisher","first-page":"17361","DOI":"10.1039\/D6CP01331G","article-title":"Dissociative single and double ionization of pyridine","volume":"28","author":"Mondal","year":"2026","journal-title":"Phys. Chem. Chem. Phys."},{"key":"2026102208070004100_cit41","doi-asserted-by":"publisher","first-page":"3","DOI":"10.1007\/BF01384654","article-title":"Differential\ncross sections of direct single electron impact ionization","volume":"1","author":"Ehrhardt","year":"1986","journal-title":"Z. Phys. D:At., Mol. Clusters"},{"key":"2026102208070004100_cit42","doi-asserted-by":"publisher","first-page":"5076","DOI":"10.1063\/1.1395555","article-title":"Electronic decay in weakly bound\nheteroclusters: Energy transfer versus electron transfer","volume":"115","author":"Zobeley","year":"2001","journal-title":"J. Chem. Phys."},{"key":"2026102208070004100_cit43","doi-asserted-by":"publisher","DOI":"10.1038\/s41467-025-61305-z","article-title":"State- and\ntime-resolved observation of ultrafast intermolecular proton transfer\nin hydrated biomolecules","volume":"16","author":"Zhou","year":"2025","journal-title":"Nat. Commun."},{"key":"2026102208070004100_cit44","doi-asserted-by":"publisher","DOI":"10.1038\/s41467-017-01133-y","article-title":"Few-femtosecond passage\nof conical intersections in the benzene cation","volume":"8","author":"Galbraith","year":"2017","journal-title":"Nat. Commun."},{"key":"2026102208070004100_cit45","doi-asserted-by":"publisher","DOI":"10.1063\/5.0024446","article-title":"Vibronic coupling\nin the ground and excited states of the pyridine radical cation","volume":"153","author":"Trofimov","year":"2020","journal-title":"J. Chem. Phys."}],"container-title":["The Journal of Physical Chemistry A"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pubs.acs.org\/doi\/pdf\/10.1021\/acs.jpca.6c05980","content-type":"application\/pdf","content-version":"vor","intended-application":"unspecified"},{"URL":"https:\/\/pubs.acs.org\/jpcafh\/article-pdf\/130\/42\/8385\/68766207\/acs.jpca.6c05980.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/pubs.acs.org\/jpcafh\/article-pdf\/130\/42\/8385\/68766207\/acs.jpca.6c05980.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,10,22]],"date-time":"2026-10-22T12:23:22Z","timestamp":1792671802000},"score":1,"resource":{"primary":{"URL":"https:\/\/pubs.acs.org\/jpcafh\/article\/130\/42\/8385\/5445786\/Microsolvation-Controls-Ultrafast-Relaxation"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,10,7]]},"references-count":45,"journal-issue":{"issue":"42","published-online":{"date-parts":[[2026,10,7]]},"published-print":{"date-parts":[[2026,10,22]]}},"URL":"https:\/\/doi.org\/10.1021\/acs.jpca.6c05980","relation":{},"ISSN":["1089-5639","1520-5215"],"issn-type":[{"value":"1089-5639","type":"print"},{"value":"1520-5215","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,10,7]]}}}