Achieving NIR Emission for Donor-Acceptor Type Platinum(II) Complexes by Adjusting Coordination Position with Isomeric Ligands

Youming Zhang, Zhao Chen, Xin Wang, Junjie He, Jiatao Wu, Haiyang Liu, Jun Song, Junle Qu, Wesley Ting Kwok Chan, Wai Yeung Wong

Research output: Journal article publicationJournal articleAcademic researchpeer-review

12 Citations (Scopus)

Abstract

Four platinum(II) complexes Pt-1, Pt-2, Pt-3, and Pt-4 with the isomeric donor-acceptor (D-A) conjugated ligand framework are designed and prepared, and their thermal, photophysical, and electrochemical characteristics investigated. Crystal structures for Pt-1 and Pt-4 are determined with single-crystal X-ray diffraction analysis, showing distorted and nonplanar geometry. Complex Pt-4 exhibits much greater distortion, attributed to the steric interactions between benzothiadiazole and naphthalene. Remarkably different photophysical, electrochemical, and electroluminescent properties are found for these platinum(II) complexes. Photoluminescence wavelengths of these complexes range from 590 to 800 nm with bandgaps of 1.7-2.0 eV. Coordination with [1,2,5]thiadiazolo[3,4-c]pyridine and triphenylamine can enhance D-A interactions, reducing the bandgap and producing near-infrared emission for Pt-3. Organic light-emitting devices (OLEDs) display electroluminescence with emission peaks at 626, 645, 826, and 571 nm, with maximum external quantum efficiencies of 0.13%, 0.04%, 0.49%, and 0.22% for Pt-1, Pt-2, Pt-3, and Pt-4 doped OLEDs, respectively. Thus, adjusting the coordination position with the isomeric conjugation framework ligand is an appropriate strategy to tune the light-emitting properties of platinum complexes in OLEDs.

Original languageEnglish
Pages (from-to)14208-14217
Number of pages10
JournalInorganic Chemistry
Volume57
Issue number22
DOIs
Publication statusPublished - 19 Nov 2018

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry

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