Acetyl protected thiol methacrylic polymers as effective ligands to keep quantum dots in luminescent standby mode

Smart photoluminescent nanohybrids based on CdSe quantum dots capped with multidentate thiolated pH‐responsive and thermoresponsive polymers for nanosensing

“…The procedure involved stirring a mixture of homemade CdSe@TOPO (6.5 × 10 −5 M) with 50 times the molar ratio of each polymer synthetized P(MEO n MA‐ co ‐AcSEMA)‐ x (3.25 × 10 −3 M) in DCM solution for 2 days. As it was described by our group for other multithiolated copolymers CdSe@P(MMA‐ co ‐AcSEMA)s, the acetyl thiol groups are able to effectively displace the original TOPO ligands of the QDs surface. The new hybrids obtained, CdSe@P(MEO n MA‐ co ‐AcSEMA)s, maintained all their physical properties intact but exhibited a low luminescent standby mode.…”

“…On other hand, the proton signals corresponding to both C H 2 S and C H 2 CH 2 S shift from 3.2 and 4.1 ppm, respectively [signals 2 and 3, Fig. (b,c)], to position occupied by other polymer protons being impossible the exact determination of their position as happened with copolymers with MMA . Moreover, an incomplete ligand exchange of the TOPO is confirmed by 1 H NMR, residual in the case of short lateral chain, MEO 2 MA [Fig.…”

“…Monodisperse and highly crystalline CdSe nanocrystals, with trioctylphosphine oxide (TOPO) as a ligand, were synthesized on a gram scale following a high‐temperature procedure described in the literature . First, a 0.2 M of selenium solution (Se) was prepared in a glove box by dissolving Se (0.170 g, 2.15 mmol) in trioctylphosphine (TOP, 10 mL, 21.5 mmol) until the solution was completely transparent.…”

“…Recently, we proposed a new methodology for coating QDs based on the ligand exchange reaction of multidentate acetylthiol‐functionalized polymers and the subsequent hydrolysis into thiol in the presence of QDs . On the basis of these results, in this work, we explore the versatility of this ligand exchange strategy for QDs using a family of thermoresponsive polymers based on ethylene glycol methacrylates with different side‐chain lengths (MEO n MA, n = 2, 3, or 8) copolymerized with a new methacrylic comonomer with a pendant acetylthiol group (AcSEMA).…”

Protected thiol strategies in macromolecular design

“…In a follow-up publication, Garcia and co-workers [192] again applied AcSEMA as a monomer with a protected thiol group in the synthesis of multi-dentate PMMA ligands for quantum dots. After ligand exchange with trioctylphosphine ligands and purification by dialysis, the thioacetate groups were hydrolyzed with the concurrent release of thiols.…”