Spontaneous multielectron transfer from the surfaces of PbS quantum dots to tetracyanoquinodimethane

Kathryn E. Knowles, Michał Malicki, Radha Parameswaran, Laura C. Cass, Emily A. Weiss

Research output: Contribution to journalArticle

21 Citations (Scopus)


This paper describes an investigation of the interfacial chemistry that enables formation of a multielectron ground-state charge-transfer (CT) complex of oleate-coated PbS quantum dots (QDs) and tetracyanoquinodimethane (TCNQ) in CHCl3 dispersions. Thermodynamically spontaneous electron transfer occurs from sulfur ions on the surfaces of the QDs (radius = 1.6 nm) to adsorbed TCNQ molecules and creates indefinitely stable ion pairs that are characterized by steady-state visible and mid-infrared absorption spectroscopy of reduced TCNQ and by NMR spectroscopy of the protons of oleate ligands that coat the QDs. The combination of these techniques shows that (i) each QD reduces an average of 4.5 TCNQ molecules, (ii) every electron transfer event between the QD and TCNQ occurs at the QD surface, (iii) sulfur ions on the surfaces of the QDs (and not delocalized states within the QDs) are the electron donors, and (iv) some TCNQ molecules adsorb directly to the surface of the QDs while others adsorb upon displacement of oleate ligands.

Original languageEnglish
Pages (from-to)7264-7271
Number of pages8
JournalJournal of the American Chemical Society
Issue number19
Publication statusPublished - May 15 2013


ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

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