{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,23]],"date-time":"2026-03-23T03:26:52Z","timestamp":1774236412561,"version":"3.50.1"},"reference-count":34,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2023,12,20]],"date-time":"2023-12-20T00:00:00Z","timestamp":1703030400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001700","name":"MEXT KAKENHI","doi-asserted-by":"publisher","award":["16H00824"],"award-info":[{"award-number":["16H00824"]}],"id":[{"id":"10.13039\/501100001700","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>The phosphole ring is known as a useful building block for constructing \u03c0-conjugated organic materials. Here, we report ladder-type benzophospholo[3,2-b]indole (BPI) derivatives where the phosphole and the pyrrole rings are directly fused. Compounds 8a\u20138d with different aryl groups on the phosphorous center were successfully synthesized, and the solid-state structure of 8a was confirmed using X-ray crystallographic analysis. The BPIs exhibit relatively high fluorescence quantum yield (\u03a6 0.50\u22120.72) and demonstrate a larger Stokes shift compared with a series of benzophospholo[3,2-b]benzoheteroles. The benzophospholo[3,2-b]carbazole derivative 9, which possesses a benzene ring between the phosphole and the pyrrole rings of the BPI, was also synthesized, and its solid-state structure was confirmed using X-ray crystallographic analysis. Compound 9 was found to show a smaller Stokes shift compared with the BPI.<\/jats:p>","DOI":"10.3390\/molecules29010038","type":"journal-article","created":{"date-parts":[[2023,12,20]],"date-time":"2023-12-20T07:20:31Z","timestamp":1703056831000},"page":"38","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["The Synthesis and Properties of Ladder-Type \u03c0-Conjugated Compounds with Pyrrole and Phosphole Rings"],"prefix":"10.3390","volume":"29","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2649-0282","authenticated-orcid":false,"given":"Minh Anh","family":"Truong","sequence":"first","affiliation":[{"name":"Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Suzuho","family":"Morishita","sequence":"additional","affiliation":[{"name":"Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Keiichi","family":"Noguchi","sequence":"additional","affiliation":[{"name":"Instrumentation Analysis Center, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4166-7074","authenticated-orcid":false,"given":"Koji","family":"Nakano","sequence":"additional","affiliation":[{"name":"Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,12,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Crassous, J., and Reau, R. 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