The Important Role of Coordination Geometry on Photophysical Properties of Blue-Green Emitting Ruthenium(II) Diisocyano Complexes Bearing 2-Benzoxazol-2-ylphenolate

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

1 Scopus Citations
View graph of relations

Author(s)

  • Pui-Yu Ho
  • Shun-Cheung Cheng
  • Shek-Man Yiu
  • Vonika Ka-Man Au
  • Jing Xiang
  • Chi-Fai Leung

Related Research Unit(s)

Detail(s)

Original languageEnglish
Pages (from-to)11372−11381
Journal / PublicationInorganic Chemistry
Volume58
Issue number17
Online published14 Aug 2019
Publication statusPublished - 3 Sep 2019

Abstract

A series of blue-green emitting RuII diisocyano complexes containing 2-benzoxazol-2-ylphenolate (PBO) have been prepared. The complexes were isolated under varied reaction conditions in two isomeric forms, i.e., trans,trans,trans- (1) and cis,trans,cis- (2), with varied ligand coordination geometry above the RuII center. The photoluminescence of the isomeric complexes has been compared and tuned by the systematic variation of the electronic properties of the isocyanides. The cis,trans,cis- isomers exhibit structureless emission in the blue-green region (471-517 nm) upon excitation at λex > 400 nm in dichloromethane solution at room temperature. Both isomeric forms show similarly structured greenish emission at 499-523 nm on excitation at λex > 355 nm in a methanol/ethanol (4:1) glassy medium at 77 K. On careful comparison with the corresponding absorption and electrochemical data, it is suggested that the solution emission of the cis,trans,cis- isomers (2) at room temperature is originated from the metal-to-ligand charge transfer (MLCT), while a ligand-centered (LC) parentage is assigned for the emission in a glassy state for both isomeric forms. In line with the above experimental results, DFT calculation demonstrates the change in the nature and relative energy of the HOMOs and LUMOs with respect to the varied ligand coordination geometry and π-accepting ability of the isocyanides.

Citation Format(s)

The Important Role of Coordination Geometry on Photophysical Properties of Blue-Green Emitting Ruthenium(II) Diisocyano Complexes Bearing 2-Benzoxazol-2-ylphenolate. / Ho, Pui-Yu; Cheng, Shun-Cheung; Yiu, Shek-Man; Au, Vonika Ka-Man; Xiang, Jing; Leung, Chi-Fai; Ko, Chi-Chiu.

In: Inorganic Chemistry, Vol. 58, No. 17, 03.09.2019, p. 11372−11381.

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