Regioselective Aromatic Substitution Reactions of Cyclometalated Ir(III) Complexes: Synthesis and Photochemical Properties of Substituted Ir(III) Complexes That Exhibit Blue, Green, and Red Color Lumi

详细信息    查看全文

• 作者：Shin Aoki ; Yasuki Matsuo ; Shiori Ogura ; Hiroki Ohwada ; Yosuke Hisamatsu ; Shinsuke Moromizato ; Motoo Shiro ; Masanori Kitamura
• 刊名：Inorganic Chemistry
• 出版年：2011
• 出版时间：February 7, 2011
• 年：2011
• 卷：50
• 期：3
• 页码：806-818
• 全文大小：1198K
• 年卷期：v.50,no.3(February 7, 2011)
• ISSN：1520-510X

文摘

In this manuscript, the regioselective halogenation, nitration, formylation, and acylation of Ir(tpy)₃ and Ir(ppy)₃ (tpy = 2-(4鈥?tolyl)pyridine and ppy = 2-phenylpyridine) and the subsequent conversions are described. During attempted bromination of the three methyl groups in fac-Ir(tpy)₃ using N-bromosuccinimide (NBS) and benzoyl peroxide (BPO), three protons at the 5鈥?position (p-position with respect to the C鈭扞r bond) of phenyl rings in tpy units were substituted by Br, as confirmed by ¹H NMR spectra, mass spectra, and X-ray crystal structure analysis. It is suggested that such substitution reactions of Ir complexes proceed via an ionic mechanism rather than a radical mechanism. UV鈭抳is and luminescence spectra of the substituted Ir(III) complexes are reported. The introduction of electron-withdrawing groups such as CN and CHO groups at the 5鈥?position of tpy induces a blue shift of luminescence emission to about 480 nm, and the introduction of electron-donating groups such as an amino group results in a red shift to about 600 nm. A reversible change of emission for the 5鈥?amino derivative of Ir(tpy)₃, Ir(atpy)₃, between red and green occurs upon protonation and deprotonation.