Core cross-linked micelle-based nanoreactors for efficient photocatalysis

Double-hydrophilic block copolymer-metal ion associations: Structures, properties and applications

Hybrid polyionic complexes (HPICs), constructed from double-hydrophilic block copolymers and metal ions, have been largely developed with increasing interest in the past decade in the fields of catalysis, materials science and biological applications. The chemical natures of both blocks are very versatile, but one block should be able to interact with ions, and the second one should be neutral. Many metals have been used to form HPICs, which have, in their simplest architectural form, a core-shell structure of a few tens of nanometers in radius with an external shell made of the neutral block of the copolymer. In this review, we focus our discussion on the stability, shape, size and inner structure of these hybrid micelles. We then describe the most recent applications of HPICs, as reported in the literature, and point out the current challenges, missing structural information and future perspectives for this class of organized structures.

Synthesis of block copolymers containing 3-chloro-2-hydroxypropyl methacrylate by NMP – a versatile platform for functionalization

This study highlights the potential of 3-chloro-2-hydroxypropyl methacrylate (ClHPMA) as a functional building block in nanostructured block copolymer architectures.

Amphiphilic polymeric nanoreactors containing Rh(i)–NHC complexes for the aqueous biphasic hydrogenation of alkenes

A rhodium(i) complex bearing a monodentate N-heterocyclic carbene ligand has been confined into the core of amphiphilic core-crosslinked micelles (CCMs).

Stepwise synthesis, characterization, DNA binding properties and cytotoxicity of diruthenium oligopyridine compounds conjugated with peptides

Although the interactions of oligopyridine ruthenium complexes with DNA have been widely studied, the biological activity of similar diruthenium oligopyridine complexes conjugated with peptides has not been investigated. Herein, we report the stepwise synthesis and characterization of diruthenium complexes with the general formula [(L^a)Ru(tppz)Ru(L^b)]ⁿ⁺ (tppz = 2,3,5,6-tetra(2-pyridyl)pyrazine, L^a = 2,2':6',2''-terpyridine or 4-phenyl-2,2':6',2''-terpyridine and L^b = 2,2':6',2''-terpyridine-4'-CO(Gly¹-Gly²-Gly³-LysCONH₂) (5), (6), n = 5; 2,2':6',2''-terpyridine-4'-CO(Gly¹-Gly²-Lys¹-Lys²CONH₂) (7), (8), n = 6; 2,2':6',2''-terpyridine-4'-CO(Ahx-Lys¹Lys²CONH₂) (9), (10), n = 5, Ahx = 6-aminohexanoic acid). The compounds [(trpy)Ru(tppz)Ru(trpy-CO₂H)](PF₆)₄, (2)(PF₆)₄, [(ptrpy)Ru(tppz)Ru(trpy-CO₂H)](PF₆)₄, (3)(PF₆)₄ and [(ptrpy)Ru(tppz)Ru(trpy)](PF₆)₄, (4)(PF₆)₄ were also characterized by single crystal X-ray methods. Moreover, the interactions of the chloride salts (5), (6) and (4) with the self-complementary dodecanucleotide duplex d(5'-CGCGAATTCGCG-3')₂ were studied by NMR spectroscopic techniques. The results show that complex (4) binds in the central part of the oligonucleotide, from the minor groove through the ligand ptrpy, while the ligand trpy, which was located on the other side of the diruthenium core, does not contribute to the binding. Complex (5) binds similarly, through the ligand ptrpy. However, the induced upfield shifts of the ptrpy proton signals are significantly lower than the corresponding ones in the case of (4), indicating much lower binding affinity. This is clear evidence that the tethered peptide Gly¹-Gly²-Gly³-Lys¹CONH₂ hinders the complex binding, even though it contains groups that are able to assist it (e.g., the positively charged amino group of lysine, the peptidic backbone, the terminal amide). Complex (6) shows a non-specific binding, interacting through electrostatic forces. The chloride salts of (4), (5) and (6) had insignificant effects on the cell cycle distribution and marginal cytotoxicity (IC₅₀ > 750 μM) against human lung cancer cell lines H1299 and H1437, indicating that their binding to the oligonucleotide is not a sufficient condition for their cytotoxicity.

Tertiary amine mediated aerobic oxidation of sulfides into sulfoxides by visible-light photoredox catalysis on TiO2

The selective oxidation of sulfides into sulfoxides receives much attention due to industrial and biological applications. However, the realization of this reaction with molecular oxygen at room temperature, which is of importance towards green and sustainable chemistry, remains challenging. Herein, we develop a strategy to achieve the aerobic oxidation of sulfides into sulfoxides by exploring the synergy between a tertiary amine and titanium dioxide via visible-light photoredox catalysis. Specifically, titanium dioxide can interact with triethylamine (TEA) to form a visible-light harvesting surface complex, preluding the ensuing selective redox reaction. Moreover, TEA, whose stability was demonstrated by a turnover number of 32, plays a critical role as a redox mediator by shuttling electrons during the oxidation of sulfide. This work suggests that the addition of a redox mediator is highly functional in establishing visible-light-induced reactions via heterogeneous photoredox catalysis.

Synthesis of cross-linked polymers via multi-component Passerini reaction and their application as efficient photocatalysts

Cross-linked polymers containing Ru complexes synthesized via multi-component Passerini reaction were shown to be highly effective and recyclable heterogeneous photocatalysts.