Synthesis of platinum(ii) complex end functionalized star polymers: luminescence enhancements and unimolecular micelles in solvents of weakened quality

Abstract

Platinum(ii) complex end functionalized star polymers have been synthesized by reacting K2PtCl4 with star ligands ended with 2,6-bis(benzimidazol-2′-yl)pyridine. They show luminescence enhancements and form unimolecular micelles in solvents of weakened quality.

Sub-10 nm Scale Lamellar Structures with a High Degree of Long-Range Order Fabricated by Orthogonal Self-Assembly of Crown Ether/Secondary Dialkylammonium Recognition and Metal···Metal/π–π Interactions

“…Low-energy absorption shoulder bands were observed at 576 and 581 nm for Pt-1-PCL and Pt-2-PCL , respectively, which were invisible in the case of Pt-3-PCL (Figure a). With reference to the previous spectroscopic studies of [Pt­(bzimpy)­Cl] + -based complexes, − ,− such low-energy absorption shoulders were clearly assigned to metal–metal-to-ligand charge transfer (MMLCT) [ d σ*­(Pt) → π*­(bzimpy)] transitions that typically originated from Pt···Pt and π–π stacking interactions between the platinum­(II) planes.…”

“…On the other hand, square-planar platinum­(II) complexes are commonly inclined to form Pt···Pt and π–π stacking interactions in both solution and solids, which correlate directly with spectroscopic properties and luminescent behaviors . We recently reported the preparation of platinum­(II) complex- block -polystyrene block copolymers and their self-assembly into micellelike aggregates in solution. − In these cases, the planar platinum­(II) complexes were employed as an isolated block to form thin coronas, where Pt···Pt and π–π stacking interactions occur and induce turn-on luminescence. Herein, for the first time, we report an orthogonal self-assembly strategy , for fabricating highly ordered lamellar structures with feature sizes less than 10 nm by combining host–guest recognition and metal···metal/π–π interactions (Figure ).…”

Synthesis of Platinum(II)-Containing Block Copolymers: Luminescence Enhancement and Controllable Self-Assembly

“…1,2,28−41 They resemble, in size, π-conjugated macrocycles, 42,43 and oligomers 44−46 that are commonly utilized to create rod−coil diblock copolymers and their functional nanoassemblies. Accordingly, the nanosized metal−ligand complexes such as zinc(II), 1,2,28−30 lanthanide(III), 1,2,28−30 and platinum(II) complexes 31−41 can be recognized as an individual, rigid building unit to microphase separate polymeric segments, leading to the creation of micelle-like aggregates in solution [31][32][33][34][35]37,38 and ordered nanostructures in thin film. 39−41 The resulting nanoassemblies can be directly imaged by using transmission electron microscopy (TEM) without any other staining as a result of the higher electron density of metal−ligand complexes than polymeric segments.…”

“…39−41 The resulting nanoassemblies can be directly imaged by using transmission electron microscopy (TEM) without any other staining as a result of the higher electron density of metal−ligand complexes than polymeric segments. [28][29][30][31][32][33][34][35]37,38,47 As part of our program to study metal-containing polymers, we recently designed and synthesized a series of [Pt(bzimpy)-Cl] + -containing polymers. [31][32][33][34][35][36]40,41 The used polymeric segments include polystyrene (PS), 31−36 PEO, 40 and poly(εcaprolactone).…”

Phosphorescent Pt(ii) complexes spatially arrayed in micellar polymeric nanoparticles providing dual readout for multimodal imaging

“…Pt(II)-complexes with luminescent properties were introduced into polymers as part of the main chain or as side and end groups utilizing post polymerizartion methods. 16–18 We designed a Pt(II) complex as the first example of a Pt(II)-based phosphorescent dye capable of being directly incorporated into a growing polymer as a side chain (Fig. 1).…”