スガヤ　トモアキ   Tomoaki Sugaya   菅谷　知明    所属   千葉工業大学  工学部 教育センター（工学部）    職種   教授
言語種別	英語
発行・発表の年月	2019/10
形態種別	学術雑誌
標題	Synthesis, X-ray structure, photophysical properties, and theoretical studies of six-membered cyclometalated iridium(III) complexes: revisiting Ir(pnbi)2(acac)
執筆形態	共著
掲載誌名	Dalton Transactions
掲載区分	国外
出版社・発行元	The Royal Society of Chemistry
巻・号・頁	48(40),pp.15212-15219
著者・共著者	Kie Yamada, Hirotoshi Mori, Tomoaki Sugaya, Makoto Tadokoro, Junichi Maeba, Koichi Nozaki, Masa-Aki Haga
概要	We have determined the X-ray structure of Ir(pnbi)2(acac) (pnbi = 2-phenanthren-9-yl-1-phenyl-1H-benzimidazole; acac = acetylacetonate), which exhibits a six-membered metallocycle around the Ir center. This result stands in sharp contrast to previously postulated structures of Ir(pnbi)2(acac), which assumed a five-membered metallocycle. In this paper, we focus on the relative stability of five- and six-membered Ir(C^N) ring structures. DFT calculations of the total energies of Ir-(C^N) complexes indicated that six-membered structures are more stable when bulky substituents are present in the benzimidazole unit. When the phenanthrene group of pnbi was replaced with a naphthalene moiety, DFT calculations predicted that five-membered cycles are more stable than six-membered rings, which was confirmed experimentally by a single-crystal X-ray diffraction analysis.
DOI	10.1039/c9dt03392k
ISSN	1477-9234
PMID	31577291