title: In situ spectroscopic characterization of a solution-phase X-type ligand exchange at colloidal lead sulphide quantum dot surfaces.
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, ΔGXC, is ∼11 kJ mol-1while at higher extents of exchange ΔGXCsaturates to ∼-4 kJ mol-1. A modified Fowler binding isotherm is developed to describe the reaction.
authors.affiliation: 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.
authors.forename: D M
authors.initials: DM
authors.lastname: Kroupa
authors.affiliation: Chemistry & Nanoscience Center, National Renewable Energy Laboratory, Golden, Colorado 80401, USA. matt.beard@nrel.gov.
authors.forename: N C
authors.initials: NC
authors.lastname: Anderson
authors.affiliation: Chemistry & Nanoscience Center, National Renewable Energy Laboratory, Golden, Colorado 80401, USA. matt.beard@nrel.gov.
authors.forename: C V
authors.initials: CV
authors.lastname: Castaneda
authors.affiliation: 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.
authors.forename: A J
authors.initials: AJ
authors.lastname: Nozik
authors.affiliation: Chemistry & Nanoscience Center, National Renewable Energy Laboratory, Golden, Colorado 80401, USA. matt.beard@nrel.gov.
authors.forename: M C
authors.identifier: http://orcid.org/0000-0002-2711-1355
authors.initials: MC
authors.lastname: Beard