Stepwise formation of iridium(III) complexes with monocyclometalating and dicyclometalating phosphorus chelates

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • Cheng-Huei Lin
  • Chih-Yuan Lin
  • Jui-Yi Hung
  • Yao-Yuan Chang
  • Min-Wen Chung
  • Yuh-Chia Chang
  • Chun Liu
  • Hsiao-An Pan
  • Gene-Hsiang Lee
  • Pi-Tai Chou

Detail(s)

Original languageEnglish
Pages (from-to)1785-1795
Journal / PublicationInorganic Chemistry
Volume51
Issue number3
Online published24 Jan 2012
Publication statusPublished - 6 Feb 2012
Externally publishedYes

Abstract

With the motivation of assembling cyclometalated complexes without nitrogen-containing heterocycle, we report here the design and systematic synthesis of a class of Ir(III) metal complexes functionalized with facially coordinated phosphite (or phosphonite) dicyclometalate tripod, together with a variety of phosphine, chelating diphosphine, or even monocyclometalate phosphite ancillaries. Thus, treatment of [IrCl 3(tht) 3] with stoichiometric amount of triphenylphosphite (or diphenyl phenylphosphonite), two equiv of PPh 3, and in presence of NaOAc as cyclometalation promoter, gives formation of respective tripodal dicyclometalating complexes [Ir(tpit)(PPh 3) 2Cl] (2a), [Ir(dppit)(PPh 3) 2Cl] (2b), and [Ir(dppit)(PMe 2Ph) 2Cl] (2c) in high yields, where tpitH 2 = triphenylphosphite and dppitH 2 = diphenyl phenylphosphonite. The reaction sequence that afforded these complexes is established. Of particular interest is isolation of an intermediate [Ir(tpitH)(PPh 3) 2Cl 2] (1a) with monocyclometalated phosphite, together with the formation of [Ir(tpit)(tpitH)(PPh 3)] (3a) with all tripodal, bidentate, and monodentate phosphorus donors coexisting on the coordination sphere, upon treatment of 2a with a second equiv of triphenylphosphite. Spectroscopic studies were performed to explore the photophysical properties. For all titled Ir(III) complexes, virtually no emission can be observed in either solution at room temperature or 77 K CH 2Cl 2 matrix. Time-dependent DFT calculation indicates that the lowest energy triplet manifold involves substantial amount of metal centered 3MC dd contribution. Due to its repulsive potential energy surface (PES) that touches the PES of ground state, the 3MC dd state executes predominant nonradiative deactivation process. 

Citation Format(s)

Stepwise formation of iridium(III) complexes with monocyclometalating and dicyclometalating phosphorus chelates. / Lin, Cheng-Huei; Lin, Chih-Yuan; Hung, Jui-Yi; Chang, Yao-Yuan; Chi, Yun; Chung, Min-Wen; Chang, Yuh-Chia; Liu, Chun; Pan, Hsiao-An; Lee, Gene-Hsiang; Chou, Pi-Tai.

In: Inorganic Chemistry, Vol. 51, No. 3, 06.02.2012, p. 1785-1795.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review