We report the time-resolved supramolecular assembly of a series of nanoscale polyoxometalate clusters (from the same one-pot reaction) of the form: [H(10+m)Ag18Cl(Te3W38O134)2]n, where n=1 and m=0 for compound 1 (after 4 days), n=2 and m=3 for compound 2 (after 10 days), and n=∞ and m=5 for compound 3 (after 14 days). The reaction is based upon the self-organization of two {Te3W38} units around a single chloride template and the formation of a {Ag12} cluster, giving a {Ag12}-in-{W76} cluster-in-cluster in compound 1, which further aggregates to cluster compounds 2 and 3 by supramolecular Ag-POM interactions. The proposed mechanism for the formation of the clusters has been studied by ESI-MS. Further, control experiments demonstrate the crucial role that TeO3(2-), Cl(-), and Ag(+) play in the self-assembly of compounds 1-3.
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http://dx.doi.org/10.1002/anie.201402932 | DOI Listing |
Macromolecules
December 2024
Dainton Building, Department of Chemistry, University of Sheffield, Brook Hill, Sheffield, South Yorkshire S3 7HF, U.K.
We report the reversible addition-fragmentation chain transfer (RAFT) dispersion polymerization of 2-hydroxyethyl methacrylate (HEMA) in -dodecane using a poly(lauryl methacrylate) (PLMA) precursor at 90 °C. This formulation is an example of polymerization-induced self-assembly (PISA), which leads to the formation of a colloidal dispersion of spherical PLMA-PHEMA nanoparticles at 10-20% w/w solids. PISA syntheses involving polar monomers in non-polar media have been previously reported but this particular system offers some unexpected and interesting challenges in terms of both synthesis and characterization.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Key Laboratory of Polyoxometalate and Reticular Material Chemistry of Ministry of Education, National & Local United Engineering Laboratory for Power Battery Institution, Northeast Normal University, Changchun, Jilin, 130024, China.
Construction of metal-organic cages (MOCs) with internal modifications is a promising avenue to build enzyme-like cavities and unlocking the mystery of highly catalytic activity and selectivity of enzymes. However, current interests are mainly focused on single-metal-node cages, little achievement has been expended to metallocluster-based architectures, and the in situ endogenous generation of metal clusters. Herein, based on the hard-soft-acids-bases (HSAB), the metallocluster-based heterometallic MOC (CuVMOP) constructed of [CuOPz] and [VO(OCH)(SO)(CO)] clusters was obtained by one-pot method.
View Article and Find Full Text PDFbioRxiv
December 2024
Department of Biochemistry and Molecular Biophysics, Columbia University Irving Medical Center, New York, NY 10032.
Time-resolved cryo-EM (TRCEM) makes it possible to provide structural and kinetic information on a reaction of biomolecules before the equilibrium is reached. Several TRCEM methods have been developed in the past to obtain key insights into the mechanism of action of molecules and molecular machines on the time scale of tens to hundreds of milliseconds, which is unattainable by the normal blotting method. Here we present our TRCEM setup utilizing a polydimethylsiloxane (PDMS)-based microfluidics chip assembly, comprising three components: a PDMS-based, internally SiO-coated micromixer, a glass-capillary microreactor, and a PDMS-based microsprayer for depositing the reaction product onto the EM grid.
View Article and Find Full Text PDFFront Chem
December 2024
School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, China.
Studies on cerium oxo clusters (CeOCs) are not only significant for understanding the redox and hydrolysis behaviors of Ce(III/IV) ions but also crucial for the rational synthesis of novel clusters and nanoceria with specific Ce(III)/Ce(IV) ratios. Here, two sets of reactions were conducted using cerium nitrate and HO-oxidized cerium nitrate, resulting in the formation of two distinct mixed-valent CeOCs [Ce Ce O(OH)(PhCO)(DMF)] (Ce) and [Ce Ce O(OH)(PhCO)(DMF)] (Ce). These two clusters exhibit different structures and Ce(III)/Ce(IV) ratios, demonstrating the critical role of cerium oxidation states and the occurrence of redox reactions in cluster formation.
View Article and Find Full Text PDFUnlabelled: Aggregating immune cells within perivascular niches (PVN) can regulate tissue immunity in infection, autoimmunity and cancer. How cells are assembled at PVNs and the activation signals imparted within remain unclear. Here, we integrate dynamic time-resolved imaging with a novel spatially-resolved platform for microanatomical interrogation of transcriptome, immune phenotype and inflammatory mediators in skin PVNs.
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