Exploring the ultrafast and isomer-dependent photodissociation of iodothiophenes via site-selective ionization
C–I bond extension and fission following ultraviolet (UV, 262 nm) photoexcitation of 2- and 3-iodothiophene is studied using ultrafast time-resolved extreme ultraviolet (XUV) ionization in conjunction with velocity map ion imaging. The photoexcited molecules and eventual I atom products are probed b...
| Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
|---|---|
| Format: | Journal article |
| Language: | English |
| Published: |
Royal Society of Chemistry
2024
|
| _version_ | 1811139292992372736 |
|---|---|
| author | Razmus, WO Allum, F Harries, J Kumagai, Y Nagaya, K Bhattacharyya, S Britton, M Brouard, M Bucksbaum, PH Cheung, K Crane, SW Fushitani, M Gabalski, I Tatsuo, G Ghrist, A Heathcote, D Hikosaka, Y Hishikawa, A Hockett, P Jones, E Kukk, E Iwayama, H Lam, HVS McManus, JW Milesevic, D Mikosch, J Minemoto, S Niozu, A Orr-Ewing, AJ Owada, S Rolles, D Rudenko, A Townsend, D Ueda, K Unwin, J Vallance, C Venkatachalam, AS Wada, S-I Walmsley, T Warne, EM Woodhouse, JL Burt, M Ashfold, MNR Minns, RS Forbes, R |
| author_facet | Razmus, WO Allum, F Harries, J Kumagai, Y Nagaya, K Bhattacharyya, S Britton, M Brouard, M Bucksbaum, PH Cheung, K Crane, SW Fushitani, M Gabalski, I Tatsuo, G Ghrist, A Heathcote, D Hikosaka, Y Hishikawa, A Hockett, P Jones, E Kukk, E Iwayama, H Lam, HVS McManus, JW Milesevic, D Mikosch, J Minemoto, S Niozu, A Orr-Ewing, AJ Owada, S Rolles, D Rudenko, A Townsend, D Ueda, K Unwin, J Vallance, C Venkatachalam, AS Wada, S-I Walmsley, T Warne, EM Woodhouse, JL Burt, M Ashfold, MNR Minns, RS Forbes, R |
| author_sort | Razmus, WO |
| collection | OXFORD |
| description | C–I bond extension and fission following ultraviolet (UV, 262 nm) photoexcitation of 2- and 3-iodothiophene is studied using ultrafast time-resolved extreme ultraviolet (XUV) ionization in conjunction with velocity map ion imaging. The photoexcited molecules and eventual I atom products are probed by site-selective ionization at the I 4d edge using intense XUV pulses, which induce multiple charges initially localized to the iodine atom. At C–I separations below the critical distance for charge transfer (CT), charge can redistribute around the molecule leading to Coulomb explosion and charged fragments with high kinetic energy. At greater C–I separations, beyond the critical distance, CT is no longer possible and the measured kinetic energies of the charged iodine atoms report on the neutral dissociation process. The time and momentum resolved measurements allow determination of the timescales and the respective product momentum and kinetic energy distributions for both isomers, which are interpreted in terms of rival ‘direct’ and ‘indirect’ dissociation pathways. The measurements are compared with a classical over the barrier model, which reveals that the onset of the indirect dissociation process is delayed by ∼1 ps relative to the direct process. The kinetics of the two processes show no discernible difference between the two parent isomers, but the branching between the direct and indirect dissociation channels and the respective product momentum distributions show isomer dependencies. The greater relative yield of indirect dissociation products from 262 nm photolysis of 3-iodothiophene (cf. 2-iodothiophene) is attributed to the different partial cross-sections for (ring-centred) π∗ ← π and (C–I bond localized) σ∗ ← (n/π) excitation in the respective parent isomers. |
| first_indexed | 2024-09-25T04:03:47Z |
| format | Journal article |
| id | oxford-uuid:92b89b3c-fe3b-40f6-b8a4-14a132ca7865 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-09-25T04:03:47Z |
| publishDate | 2024 |
| publisher | Royal Society of Chemistry |
| record_format | dspace |
| spelling | oxford-uuid:92b89b3c-fe3b-40f6-b8a4-14a132ca78652024-05-09T16:08:53ZExploring the ultrafast and isomer-dependent photodissociation of iodothiophenes via site-selective ionizationJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:92b89b3c-fe3b-40f6-b8a4-14a132ca7865EnglishSymplectic ElementsRoyal Society of Chemistry2024Razmus, WOAllum, FHarries, JKumagai, YNagaya, KBhattacharyya, SBritton, MBrouard, MBucksbaum, PHCheung, KCrane, SWFushitani, MGabalski, ITatsuo, GGhrist, AHeathcote, DHikosaka, YHishikawa, AHockett, PJones, EKukk, EIwayama, HLam, HVSMcManus, JWMilesevic, DMikosch, JMinemoto, SNiozu, AOrr-Ewing, AJOwada, SRolles, DRudenko, ATownsend, DUeda, KUnwin, JVallance, CVenkatachalam, ASWada, S-IWalmsley, TWarne, EMWoodhouse, JLBurt, MAshfold, MNRMinns, RSForbes, RC–I bond extension and fission following ultraviolet (UV, 262 nm) photoexcitation of 2- and 3-iodothiophene is studied using ultrafast time-resolved extreme ultraviolet (XUV) ionization in conjunction with velocity map ion imaging. The photoexcited molecules and eventual I atom products are probed by site-selective ionization at the I 4d edge using intense XUV pulses, which induce multiple charges initially localized to the iodine atom. At C–I separations below the critical distance for charge transfer (CT), charge can redistribute around the molecule leading to Coulomb explosion and charged fragments with high kinetic energy. At greater C–I separations, beyond the critical distance, CT is no longer possible and the measured kinetic energies of the charged iodine atoms report on the neutral dissociation process. The time and momentum resolved measurements allow determination of the timescales and the respective product momentum and kinetic energy distributions for both isomers, which are interpreted in terms of rival ‘direct’ and ‘indirect’ dissociation pathways. The measurements are compared with a classical over the barrier model, which reveals that the onset of the indirect dissociation process is delayed by ∼1 ps relative to the direct process. The kinetics of the two processes show no discernible difference between the two parent isomers, but the branching between the direct and indirect dissociation channels and the respective product momentum distributions show isomer dependencies. The greater relative yield of indirect dissociation products from 262 nm photolysis of 3-iodothiophene (cf. 2-iodothiophene) is attributed to the different partial cross-sections for (ring-centred) π∗ ← π and (C–I bond localized) σ∗ ← (n/π) excitation in the respective parent isomers. |
| spellingShingle | Razmus, WO Allum, F Harries, J Kumagai, Y Nagaya, K Bhattacharyya, S Britton, M Brouard, M Bucksbaum, PH Cheung, K Crane, SW Fushitani, M Gabalski, I Tatsuo, G Ghrist, A Heathcote, D Hikosaka, Y Hishikawa, A Hockett, P Jones, E Kukk, E Iwayama, H Lam, HVS McManus, JW Milesevic, D Mikosch, J Minemoto, S Niozu, A Orr-Ewing, AJ Owada, S Rolles, D Rudenko, A Townsend, D Ueda, K Unwin, J Vallance, C Venkatachalam, AS Wada, S-I Walmsley, T Warne, EM Woodhouse, JL Burt, M Ashfold, MNR Minns, RS Forbes, R Exploring the ultrafast and isomer-dependent photodissociation of iodothiophenes via site-selective ionization |
| title | Exploring the ultrafast and isomer-dependent photodissociation of iodothiophenes via site-selective ionization |
| title_full | Exploring the ultrafast and isomer-dependent photodissociation of iodothiophenes via site-selective ionization |
| title_fullStr | Exploring the ultrafast and isomer-dependent photodissociation of iodothiophenes via site-selective ionization |
| title_full_unstemmed | Exploring the ultrafast and isomer-dependent photodissociation of iodothiophenes via site-selective ionization |
| title_short | Exploring the ultrafast and isomer-dependent photodissociation of iodothiophenes via site-selective ionization |
| title_sort | exploring the ultrafast and isomer dependent photodissociation of iodothiophenes via site selective ionization |
| work_keys_str_mv | AT razmuswo exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT allumf exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT harriesj exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT kumagaiy exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT nagayak exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT bhattacharyyas exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT brittonm exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT brouardm exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT bucksbaumph exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT cheungk exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT cranesw exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT fushitanim exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT gabalskii exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT tatsuog exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT ghrista exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT heathcoted exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT hikosakay exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT hishikawaa exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT hockettp exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT jonese exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT kukke exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT iwayamah exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT lamhvs exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT mcmanusjw exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT milesevicd exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT mikoschj exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT minemotos exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT niozua exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT orrewingaj exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT owadas exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT rollesd exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT rudenkoa exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT townsendd exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT uedak exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT unwinj exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT vallancec exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT venkatachalamas exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT wadasi exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT walmsleyt exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT warneem exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT woodhousejl exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT burtm exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT ashfoldmnr exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT minnsrs exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization AT forbesr exploringtheultrafastandisomerdependentphotodissociationofiodothiophenesviasiteselectiveionization |