Iridium(III) Complexes Formed by O-H and/Or C-H Activation of 2-(Arylazo)phenols
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- 作者：Rama Acharyya ; Falguni Basuli ; Ren-Zhang Wang ; Thomas C. W. Mak ; and Samaresh Bhattacharya
- 刊名：Inorganic Chemistry
- 出版年：2004
- 出版时间：January 26, 2004
- 年：2004
- 卷：43
- 期：2
- 页码：704 - 711
- 全文大小：196K
- 年卷期：v.43,no.2(January 26, 2004)
- ISSN：1520-510X
文摘
Reaction of 2-(arylazo)phenols with [Ir(PPh3)3Cl] in refluxing ethanol in the presence of a base (NEt3) affords complexes of three different types, viz. [Ir(PPh3)2(NO-R)(H)Cl] (R = OCH3, CH3, H, Cl and NO2), [Ir(PPh3)2(NO-R)(H)2] and [Ir(PPh3)2(CNO-R)(H)]. Structures of the [Ir(PPh3)2(NO-Cl)(H)Cl], [Ir(PPh3)2(NO-Cl)(H)2] and [Ir(PPh3)2(CNO-Cl)(H)] complexes have been determined by X-ray crystallography. In the [Ir(PPh3)2(NO-R)(H)Cl] and[Ir(PPh3)2(NO-R)(H)2] complexes, the 2-(arylazo)phenolate ligands are coordinated to the metal center as monoanionicbidentate N,O-donors, whereas in the [Ir(PPh3)2(CNO-R)(H)] complexes, they are coordinated to iridium as dianionictridentate C,N,O-donors. In all three products formed in ethanol, the two PPh3 ligands are trans. Reaction of2-(arylazo)phenols with [Ir(PPh3)3Cl] in refluxing toluene in the presence of NEt3 affords complexes of two types,viz. [Ir(PPh3)2(CNO-R)(H)] and [Ir(PPh3)2(CNO-R)Cl]. Structure of the [Ir(PPh3)2(CNO-Cl)Cl] complex has beendetermined by X-ray crystallography, and the 2-(arylazo)phenolate ligand is coordinated to the metal center as adianionic tridentate C,N,O-donor and the two PPh3 ligands are cis. All of the iridium(III) complexes show intenseMLCT transitions in the visible region. Cyclic voltammetry shows an Ir(III)-Ir(IV) oxidation on the positive side ofSCE and an Ir(III)-Ir(II) reduction on the negative side for all of the products.