{"title":"通过高分辨率光电子能谱分析氧化镁的基态 X$^+$ $^2\\Pi_{\\Omega}$ 和第一激发态 A$^+$ $^2\\Sigma^+$ 电子态的特征","authors":"C. Kreis, J. R. Schmitz and F. Merkt","doi":"10.1039/D4CP01944J","DOIUrl":null,"url":null,"abstract":"<p >Despite the importance of MgO<small><sup>+</sup></small> for understanding the electronic structure and chemical bonds in alkaline-earth metal oxides and its potential astrophysical relevance, hardly any spectroscopic information is available on this molecular cation. We report on a high-resolution photoelectron spectroscopic study of MgO using a resonant (1 + 1′) two-photon excitation scheme in combination with PFI-ZEKE photoelectron spectroscopy. By carrying out the resonant excitation <em>via</em> selected rotational levels of several intermediate states of different electronic configurations, total electronic spins, and internuclear distances, a broad range of vibrational levels of the X<small><sup>+ 2</sup></small>Π<small><sub><em>Ω</em></sub></small> (<em>Ω</em> = 3/2, 1/2) ground and A<small><sup>+ 2</sup></small>Σ<small><sup>+</sup></small> first excited states of MgO<small><sup>+</sup></small> were observed for the first time. The new data provide a full characterisation of the rovibronic level structure of MgO<small><sup>+</sup></small> up to 2 eV (16 000 cm<small><sup>−1</sup></small>) of internal energy. A full set of vibrational, rotational and spin–orbit-coupling molecular constants were extracted for these two electronic states. The adiabatic ionisation energy and the singlet–triplet interval of <small><sup>24</sup></small>Mg<small><sup>16</sup></small>O were determined to be 64 577.65(20) cm<small><sup>−1</sup></small> and 2492.4(3) cm<small><sup>−1</sup></small>, respectively.</p>","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":null,"pages":null},"PeriodicalIF":2.9000,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/cp/d4cp01944j?page=search","citationCount":"0","resultStr":"{\"title\":\"Characterisation of the ground X+ 2ΠΩ and first excited A+ 2Σ+ electronic states of MgO+ by high-resolution photoelectron spectroscopy\",\"authors\":\"C. Kreis, J. R. Schmitz and F. Merkt\",\"doi\":\"10.1039/D4CP01944J\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p >Despite the importance of MgO<small><sup>+</sup></small> for understanding the electronic structure and chemical bonds in alkaline-earth metal oxides and its potential astrophysical relevance, hardly any spectroscopic information is available on this molecular cation. We report on a high-resolution photoelectron spectroscopic study of MgO using a resonant (1 + 1′) two-photon excitation scheme in combination with PFI-ZEKE photoelectron spectroscopy. By carrying out the resonant excitation <em>via</em> selected rotational levels of several intermediate states of different electronic configurations, total electronic spins, and internuclear distances, a broad range of vibrational levels of the X<small><sup>+ 2</sup></small>Π<small><sub><em>Ω</em></sub></small> (<em>Ω</em> = 3/2, 1/2) ground and A<small><sup>+ 2</sup></small>Σ<small><sup>+</sup></small> first excited states of MgO<small><sup>+</sup></small> were observed for the first time. The new data provide a full characterisation of the rovibronic level structure of MgO<small><sup>+</sup></small> up to 2 eV (16 000 cm<small><sup>−1</sup></small>) of internal energy. A full set of vibrational, rotational and spin–orbit-coupling molecular constants were extracted for these two electronic states. The adiabatic ionisation energy and the singlet–triplet interval of <small><sup>24</sup></small>Mg<small><sup>16</sup></small>O were determined to be 64 577.65(20) cm<small><sup>−1</sup></small> and 2492.4(3) cm<small><sup>−1</sup></small>, respectively.</p>\",\"PeriodicalId\":99,\"journal\":{\"name\":\"Physical Chemistry Chemical Physics\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.9000,\"publicationDate\":\"2024-06-25\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://pubs.rsc.org/en/content/articlepdf/2024/cp/d4cp01944j?page=search\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Physical Chemistry Chemical Physics\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://pubs.rsc.org/en/content/articlelanding/2024/cp/d4cp01944j\",\"RegionNum\":3,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"CHEMISTRY, PHYSICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Physical Chemistry Chemical Physics","FirstCategoryId":"92","ListUrlMain":"https://pubs.rsc.org/en/content/articlelanding/2024/cp/d4cp01944j","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
Characterisation of the ground X+ 2ΠΩ and first excited A+ 2Σ+ electronic states of MgO+ by high-resolution photoelectron spectroscopy
Despite the importance of MgO+ for understanding the electronic structure and chemical bonds in alkaline-earth metal oxides and its potential astrophysical relevance, hardly any spectroscopic information is available on this molecular cation. We report on a high-resolution photoelectron spectroscopic study of MgO using a resonant (1 + 1′) two-photon excitation scheme in combination with PFI-ZEKE photoelectron spectroscopy. By carrying out the resonant excitation via selected rotational levels of several intermediate states of different electronic configurations, total electronic spins, and internuclear distances, a broad range of vibrational levels of the X+ 2ΠΩ (Ω = 3/2, 1/2) ground and A+ 2Σ+ first excited states of MgO+ were observed for the first time. The new data provide a full characterisation of the rovibronic level structure of MgO+ up to 2 eV (16 000 cm−1) of internal energy. A full set of vibrational, rotational and spin–orbit-coupling molecular constants were extracted for these two electronic states. The adiabatic ionisation energy and the singlet–triplet interval of 24Mg16O were determined to be 64 577.65(20) cm−1 and 2492.4(3) cm−1, respectively.
期刊介绍:
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