In situ spectroscopic characterization of a solution-phase X-type ligand exchange at colloidal lead sulphide quantum dot surfaces

D M Kroupa; N C Anderson; C V Castaneda; A J Nozik; M C Beard

doi:10.1039/c6cc08114b

In situ spectroscopic characterization of a solution-phase X-type ligand exchange at colloidal lead sulphide quantum dot surfaces

Chem Commun (Camb). 2016 Nov 24;52(96):13893-13896. doi: 10.1039/c6cc08114b.

Authors

D M Kroupa¹, N C Anderson², C V Castaneda², A J Nozik¹, M C Beard²

Affiliations

¹ Chemistry & Nanoscience Center, National Renewable Energy Laboratory, Golden, Colorado 80401, USA. matt.beard@nrel.gov and Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, USA.
² Chemistry & Nanoscience Center, National Renewable Energy Laboratory, Golden, Colorado 80401, USA. matt.beard@nrel.gov.

PMID: 27841383
DOI: 10.1039/c6cc08114b

Abstract

We employed quantitative NMR spectroscopy and spectrophotometric absorbance titration to study a quantum dot X-type ligand exchange reaction. We find that the exchange is highly cooperative, where at low extents of exchange the change in free energy of the reaction, ΔG_XC, is ∼11 kJ mol^-1 while at higher extents of exchange ΔG_XC saturates to ∼-4 kJ mol^-1. A modified Fowler binding isotherm is developed to describe the reaction.