TY - JOUR A1 - Kim, Jiyong A1 - Kim, Yohan A1 - Park, Kyoungwon A1 - Boeffel, Christine A1 - Choi, Hyung-Seok A1 - Taubert, Andreas A1 - Wedel, Armin T1 - Ligand Effect in 1-Octanethiol Passivation of InP/ZnSe/ZnS Quantum Dots-Evidence of Incomplete Surface Passivation during Synthesis JF - Small : nano micro N2 - The lack of anionic carboxylate ligands on the surface of InP/ZnSe/ZnS quantum dots (QDs), where zinc carboxylate ligands can be converted to carboxylic acid or carboxylate ligands via proton transfer by 1-octanethiol, is demonstrated. The as-synthesized QDs initially have an under-coordinated vacancy surface, which is passivated by solvent ligands such as ethanol and acetone. Upon exposure of 1-octanethiol to the QD surface, 1-octanethiol effectively induces the surface binding of anionic carboxylate ligands (derived from zinc carboxylate ligands) by proton transfer, which consequently exchanges ethanol and acetone ligands that bind on the incomplete QD surface. These systematic chemical analyses, such as thermogravimetric analysis-mass spectrometry and proton nuclear magnetic resonance spectroscopy, directly show the interplay of surface ligands, and it associates with QD light-emitting diodes (QD-LEDs). It is believed that this better understanding can lead to industrially feasible QD-LEDs. KW - colloidal quantum dots KW - incomplete surface passivation KW - indium KW - phosphide KW - surface chemistry KW - thiol passivation Y1 - 2022 U6 - https://doi.org/10.1002/smll.202203093 SN - 1613-6810 SN - 1613-6829 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Enzenberg, Anne A1 - Laschewsky, Andre A1 - Boeffel, Christine A1 - Wischerhoff, Erik T1 - Influence of the Near Molecular Vicinity on the Temperature Regulated Fluorescence Response of Poly(N-vinylcaprolactam) JF - Polymers N2 - A series of new fluorescent dye bearing monomers, including glycomonomers, based on maleamide and maleic esteramide was synthesized. The dye monomers were incorporated by radical copolymerization into thermo-responsive poly(N‑vinyl-caprolactam) that displays a lower critical solution temperature (LCST) in aqueous solution. The effects of the local molecular environment on the polymers’ luminescence, in particular on the fluorescence intensity and the extent of solvatochromism, were investigated below as well as above the phase transition. By attaching substituents of varying size and polarity in the close vicinity of the fluorophore, and by varying the spacer groups connecting the dyes to the polymer backbone, we explored the underlying structure–property relationships, in order to establish rules for successful sensor designs, e.g., for molecular thermometers. Most importantly, spacer groups of sufficient length separating the fluorophore from the polymer backbone proved to be crucial for obtaining pronounced temperature regulated fluorescence responses. View Full-Text KW - thermo-responsive polymers KW - poly(N-vinylcaprolactam) KW - lower critical solution temperature KW - fluorescent dyemonomers KW - naphthalimide KW - solvatochromism KW - polymeric sensors KW - molecular thermometers Y1 - 2016 U6 - https://doi.org/10.3390/polym8040109 SN - 2073-4360 VL - 8 PB - MDPI CY - Basel ER - TY - GEN A1 - Enzenberg, Anne A1 - Laschewsky, André A1 - Boeffel, Christine A1 - Wischerhoff, Erik T1 - Influence of the near molecular vicinity on the temperature regulated fluorescence response of poly(N-vinylcaprolactam) N2 - A series of new fluorescent dye bearing monomers, including glycomonomers, based on maleamide and maleic esteramide was synthesized. The dye monomers were incorporated by radical copolymerization into thermo-responsive poly(N-vinyl-caprolactam) that displays a lower critical solution temperature (LCST) in aqueous solution. The effects of the local molecular environment on the polymers' luminescence, in particular on the fluorescence intensity and the extent of solvatochromism, were investigated below as well as above the phase transition. By attaching substituents of varying size and polarity in the close vicinity of the fluorophore, and by varying the spacer groups connecting the dyes to the polymer backbone, we explored the underlying structure-property relationships, in order to establish rules for successful sensor designs, e.g., for molecular thermometers. Most importantly, spacer groups of sufficient length separating the fluorophore from the polymer backbone proved to be crucial for obtaining pronounced temperature regulated fluorescence responses. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 363 KW - thermo-responsive polymers KW - poly(N-vinylcaprolactam) KW - lower critical solution temperature KW - fluorescent dyemonomers KW - naphthalimide KW - solvatochromism KW - polymeric sensors KW - molecular thermometers Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-400634 ER -