Keishiro Tahara*, Akihito Kobayashi, Mamoru Fujitsuka, Yasuko Osakada, Ken Tokunaga, Takashi Ikeda and Masaaki Abe*,
{"title":"吡啶配体与苯并噻吩 (BTBT) 单元的环甲基化铂(II)配合物:合成、光物理性质以及中心配体在激发态的异常偏移","authors":"Keishiro Tahara*, Akihito Kobayashi, Mamoru Fujitsuka, Yasuko Osakada, Ken Tokunaga, Takashi Ikeda and Masaaki Abe*, ","doi":"10.1021/acs.organomet.4c00019","DOIUrl":null,"url":null,"abstract":"<p >A cyclometalated Pt(II) complex was synthesized by appending a pyridyl ligand containing a benzothienobenzothiophene (BTBT) unit, which is a well-known small organic molecule semiconductor. The target complex [Pt(ppy)(BTBT-py)Cl] (<b>2</b>) was characterized by <sup>1</sup>H NMR, steady-state UV–vis absorption, and photoluminescence spectroscopies in comparison with [Pt(ppy)(ppyH)Cl] (<b>1</b>) and BTBT-py (where ppy = 2-phenylpyridine and BTBT-py = 2-(3-pyridyl)-[1]benzothieno[3,2-<i>b</i>][1]benzothiophene). Complex <b>2</b> exhibited absorption bands derived from the ppy-centered π–π* transition and intramolecular charge transfer (ICT) from BTBT to pyridine moieties, indicating that <b>2</b> inherited the combined properties of the parent complex <b>1</b> and the parent ligand BTBT-py. Moreover, DFT calculations showed that <b>2</b> inherited HOMO and LUMO characteristics from BTBT-py as well as HOMO–1 and LUMO+1 characteristics from <b>1</b>. While BTBT-py showed fluorescence from the <sup>1</sup>ICT state, the corresponding fluorescence was quenched in <b>2</b> because the Pt center, a heavy atom, enhanced the intersystem crossing. The ancillary ligand-centered <sup>3</sup>ICT, rather than the ppy-centered <sup>3</sup>π–π*, state was successfully monitored in <b>2</b> using femtosecond transient absorption spectroscopy. Replacing the phenyl group with the BTBT unit in the cyclometalated Pt(II) complex restructured the electronic structure of the lowest triplet excited state, shifting the centered ligand from ppy to BTBT-py.</p>","PeriodicalId":56,"journal":{"name":"Organometallics","volume":null,"pages":null},"PeriodicalIF":2.5000,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Cyclometalated Pt(II) Complex Appending a Pyridyl Ligand with a Benzothienobenzothiophene (BTBT) Unit: Synthesis, Photophysical Properties, and an Unusual Shift of Centered Ligands in Excited States\",\"authors\":\"Keishiro Tahara*, Akihito Kobayashi, Mamoru Fujitsuka, Yasuko Osakada, Ken Tokunaga, Takashi Ikeda and Masaaki Abe*, \",\"doi\":\"10.1021/acs.organomet.4c00019\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p >A cyclometalated Pt(II) complex was synthesized by appending a pyridyl ligand containing a benzothienobenzothiophene (BTBT) unit, which is a well-known small organic molecule semiconductor. The target complex [Pt(ppy)(BTBT-py)Cl] (<b>2</b>) was characterized by <sup>1</sup>H NMR, steady-state UV–vis absorption, and photoluminescence spectroscopies in comparison with [Pt(ppy)(ppyH)Cl] (<b>1</b>) and BTBT-py (where ppy = 2-phenylpyridine and BTBT-py = 2-(3-pyridyl)-[1]benzothieno[3,2-<i>b</i>][1]benzothiophene). Complex <b>2</b> exhibited absorption bands derived from the ppy-centered π–π* transition and intramolecular charge transfer (ICT) from BTBT to pyridine moieties, indicating that <b>2</b> inherited the combined properties of the parent complex <b>1</b> and the parent ligand BTBT-py. Moreover, DFT calculations showed that <b>2</b> inherited HOMO and LUMO characteristics from BTBT-py as well as HOMO–1 and LUMO+1 characteristics from <b>1</b>. While BTBT-py showed fluorescence from the <sup>1</sup>ICT state, the corresponding fluorescence was quenched in <b>2</b> because the Pt center, a heavy atom, enhanced the intersystem crossing. The ancillary ligand-centered <sup>3</sup>ICT, rather than the ppy-centered <sup>3</sup>π–π*, state was successfully monitored in <b>2</b> using femtosecond transient absorption spectroscopy. Replacing the phenyl group with the BTBT unit in the cyclometalated Pt(II) complex restructured the electronic structure of the lowest triplet excited state, shifting the centered ligand from ppy to BTBT-py.</p>\",\"PeriodicalId\":56,\"journal\":{\"name\":\"Organometallics\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.5000,\"publicationDate\":\"2024-04-03\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Organometallics\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://pubs.acs.org/doi/10.1021/acs.organomet.4c00019\",\"RegionNum\":3,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"CHEMISTRY, INORGANIC & NUCLEAR\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Organometallics","FirstCategoryId":"92","ListUrlMain":"https://pubs.acs.org/doi/10.1021/acs.organomet.4c00019","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, INORGANIC & NUCLEAR","Score":null,"Total":0}
Cyclometalated Pt(II) Complex Appending a Pyridyl Ligand with a Benzothienobenzothiophene (BTBT) Unit: Synthesis, Photophysical Properties, and an Unusual Shift of Centered Ligands in Excited States
A cyclometalated Pt(II) complex was synthesized by appending a pyridyl ligand containing a benzothienobenzothiophene (BTBT) unit, which is a well-known small organic molecule semiconductor. The target complex [Pt(ppy)(BTBT-py)Cl] (2) was characterized by 1H NMR, steady-state UV–vis absorption, and photoluminescence spectroscopies in comparison with [Pt(ppy)(ppyH)Cl] (1) and BTBT-py (where ppy = 2-phenylpyridine and BTBT-py = 2-(3-pyridyl)-[1]benzothieno[3,2-b][1]benzothiophene). Complex 2 exhibited absorption bands derived from the ppy-centered π–π* transition and intramolecular charge transfer (ICT) from BTBT to pyridine moieties, indicating that 2 inherited the combined properties of the parent complex 1 and the parent ligand BTBT-py. Moreover, DFT calculations showed that 2 inherited HOMO and LUMO characteristics from BTBT-py as well as HOMO–1 and LUMO+1 characteristics from 1. While BTBT-py showed fluorescence from the 1ICT state, the corresponding fluorescence was quenched in 2 because the Pt center, a heavy atom, enhanced the intersystem crossing. The ancillary ligand-centered 3ICT, rather than the ppy-centered 3π–π*, state was successfully monitored in 2 using femtosecond transient absorption spectroscopy. Replacing the phenyl group with the BTBT unit in the cyclometalated Pt(II) complex restructured the electronic structure of the lowest triplet excited state, shifting the centered ligand from ppy to BTBT-py.
期刊介绍:
Organometallics is the flagship journal of organometallic chemistry and records progress in one of the most active fields of science, bridging organic and inorganic chemistry. The journal publishes Articles, Communications, Reviews, and Tutorials (instructional overviews) that depict research on the synthesis, structure, bonding, chemical reactivity, and reaction mechanisms for a variety of applications, including catalyst design and catalytic processes; main-group, transition-metal, and lanthanide and actinide metal chemistry; synthetic aspects of polymer science and materials science; and bioorganometallic chemistry.