Browse
Submit Data
Databases
API
Help

Dataset Information

10 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Enhanced photoreduction of water catalyzed by a cucurbit[8]uril-secured platinum dimer.

ABSTRACT: A cucurbit[8]uril (CB[8])-secured platinum terpyridyl chloride dimer was used as a photosensitizer and hydrogen-evolving catalyst for the photoreduction of water. Volumes of produced hydrogen were up to 25 and 6 times larger than those obtained with the corresponding free and cucurbit[7]uril-bound platinum monomer, respectively, at equal Pt concentration. The thermodynamics of the proton-coupled electron transfer from the Pt(ii)-Pt(ii) dimer to the corresponding Pt(ii)-Pt(iii)-H hydride key intermediate, as quantified by density functional theory, suggest that CB[8] secures the Pt(ii)-Pt(ii) dimer in a particularly reactive conformation that promotes hydrogen formation.

SUBMITTER: Rabbani R

PROVIDER: S-EPMC8635170 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Cucurbit[10]uril.

Project description:Melamine diamine 1 is able to displace CB[5] from the CB[10].CB[5] complex resulting in CB[10].12 and precipitated CB[5].1. We were able to isolate free CB[10] by treatment of CB[10].1 with acetic anhydride followed by washing with MeOH, DMSO, and water. The spacious cavity of CB[10] is able to complex large guests, including a cationic calix[4]arene derivative in its 1,3-alternate form (CB[10].1,3-alt-3). The addition of adamantane carboxylic acid (4) to CB[10].3 triggers a conformational change during the formation of termolecular complex CB[10].cone-3.4.

| S-EPMC2538447 | biostudies-literature

Acyclic Cucurbit[n]uril Dendrimers.

Project description:The synthesis of acyclic cucurbit[n]uril dendrimers G1-G3 that bear four dendrons on their aromatic sidewalls via thiolate S(N)2 chemistry is reported. G1-G3 are polycationic and can bind to pEGFP plasmid DNA as shown by dynamic light scattering (DLS), gel electrophoresis, and scanning electron microscopy (SEM). The gene delivery ability of G1-G3 is presented.

| S-EPMC4670575 | biostudies-literature

Enhanced Energy Conversion of Z907-Based Solar Cells by Cucurbit[7]uril Macrocycles.

Project description:A dye-sensitized solar cell was constructed on the basis of encapsulating the ruthenium polypyridyl photosensitizer Z907 in the macrocycle cucurbit[7]uril (CB7). The work focuses on the photophysical properties of the new host-guest complexes in acetonitrile and water (volume ratio 1:9) and on the top of nanocrystalline titanium dioxide (TiO2) electrode prior to the addition of poly(3-hexylthiophene) polymer and gold electrode. Complexation to CB7 in aqueous solutions has decreased the emission intensity and excited-state lifetime for metal-to-ligand charge transfer (MLCT) state at 650 nm by twofold because of collisional quenching, which opens a non-radiative deactivation channel. Similarly, a twofold decrease in the emission intensity and excited-state lifetime of MLCT at 750 nm on the top of TiO2 electrodes was observed with the addition of CB7. Encapsulation of Z907 dye to CB7 host has, also, led to fourfold enhancement in the short circuit current and power conversion efficiency of the final solar cell. The results support the premise that host-guest complexation of CB7 facilitates faster electron injection from Z907 dye into the conduction band of TiO2 electrodes.

| S-EPMC6694293 | biostudies-literature

4-Sulfocalix[4]arene/Cucurbit[7]uril-Based Supramolecular Assemblies through the Outer Surface Interactions of Cucurbit[<i>n</i>]uril.

Project description:Upon mixing of aqueous solutions of the freely soluble building blocks cucurbit[7]uril (Q[7]) and 4-sulfocalix[4]arene (SC[4]A), white microcrystals instantly separate in near-quantitative yield. The driving force for this assembly is suggested to be the outer-surface interaction of the Q[n]. Dynamic light scattering, scanning electron microscopy, and NMR (diffusion-ordered NMR spectroscopy) analyses have confirmed the supramolecular aggregation of Q[7] and SC[4]A. Titration 1H NMR spectroscopy and isothermal titration calorimetry have shown that the interaction ratio of Q[7] and SC[4]A is close to 3:1. Moreover, the Q[7]/SC[4]A-based supramolecular assembly can accommodate molecules of some volatile compounds or luminescent dyes. Thus, this work offers a simple and highly efficient means of preparing adsorbent or solid fluorescent materials.

| S-EPMC6644559 | biostudies-literature

Cucurbit[7]uril-based high-performance catalytic microreactors.

Project description:Catalytic microreactors manufactured using microfluidic devices have received significant research interest in recent years. However, little attention has been paid to immobilising metallic nanoparticles (NPs) onto microchannel walls for high efficiency catalytic reactions. We demonstrate a facile preparation of cucurbit[7]uril-based catalytic microreactors, where metallic NPs are immobilised onto microchannels via supramolecular complexation with methyl viologen@cucurbit[7]uril (CB[7]). These microreactors exhibit a remarkable catalytic activity owing to the substantially high surface area to volume ratio of the microchannels and metallic NPs. Superior to most conventional heterogeneous catalytic reactions, separation post reaction and complicated recycling steps of the catalysts are not required. Moreover, CB[7] can complex a variety of metallic NPs to its portal, providing a multifunctional high-performance in situ catalytic platform.

| S-EPMC6088369 | biostudies-other

pH-Mediated Single Molecule Conductance of Cucurbit[7]uril.

Project description:Recognition tunneling technique owns the capability for investigating and characterizing molecules at single molecule level. Here, we investigated the conductance value of cucurbit[7]uril (CB[7]) and melphalan@CB[7] (Mel@CB[7]) complex molecular junctions by using recognition tunneling technique. The conductances of CB[7] and Mel@CB[7] with different pH values were studied in aqueous media as well as organic solvent. Both pH value and guest molecule have an impact on the conductance of CB[7] molecular junction. The conductances of CB[7] and Mel@CB[7] both showed slightly difference on the conductance under different measurement systems. This work extends the molecular conductance measurement to aqueous media and provides new insights of pH-responsive host-guest system for single molecule detection through electrical measurements.

| S-EPMC7477741 | biostudies-literature

Design and recognition of cucurbituril-secured platinum-bound oligopeptides.

Project description:Platinum terpyridyl complexes, stacked on top of one another and secured as dimers with cucurbit[8]uril (CB[8]) in aqueous medium, were functionalized quantitatively and in situ with a pair of pentapeptides Phe-(Gly)3-Cys by grafting their cysteine residues to the Pt centers. The resulting CB[8]·(Pt·peptide)2 assemblies were used to target secondary hosts CB[7] and CB[8] via their pair of phenylalanine residues, again in situ. A series of well-defined architectures, including a supramolecular "pendant necklace" with hybrid head-to-head and head-to-tail arrangements inside CB[8], were obtained during the self-sorting process after combining only 3 or 4 simple building units.

| S-EPMC8317623 | biostudies-literature

A Cobalt@Cucurbit[5]uril Complex as a Highly Efficient Supramolecular Catalyst for Electrochemical and Photoelectrochemical Water Splitting.

Project description:A host-guest complex self-assembled through Co2+ and cucurbit[5]uril (Co@CB[5]) is used as a supramolecular catalyst on the surface of metal oxides including porous indium tin oxide (ITO) and porous BiVO4 for efficient electrochemical and photoelectrochemical water oxidation. When immobilized on ITO, Co@CB[5] exhibited a turnover frequency (TOF) of 9.9 s-1 at overpotential η=550 mV in a pH 9.2 borate buffer. Meanwhile, when Co@CB[5] complex was immobilized onto the surface of BiVO4 semiconductor, the assembled Co@CB[5]/BiVO4 photoanode exhibited a low onset potential of 0.15 V (vs. RHE) and a high photocurrent of 4.8 mA cm-2 at 1.23 V (vs. RHE) under 100 mW cm-2 (AM 1.5) light illumination. Kinetic studies confirmed that Co@CB[5] acts as a supramolecular water oxidation catalyst, and can effectively accelerate interfacial charge transfer between BiVO4 and electrolyte. Surface charge recombination of BiVO4 can be also significantly suppressed by Co@CB[5].

| S-EPMC7894348 | biostudies-literature

A Supramolecular Approach for Enhanced Antibacterial Activity and Extended Shelf-life of Fluoroquinolone Drugs with Cucurbit[7]uril.

Project description:The host-guest interactions of a third-generation fluoroquinone, danofloxacin (DOFL), with the macrocyclic host cucurbit[7]uril (CB7) have been investigated at different pH values (~3.5, 7.5, and 10). The photophysical properties have been positively affected, that is, the fluorescence yield and lifetime increased, as well as the photostability of DOFL improved in the presence of CB7. The antibacterial activity of DOFL is enhanced in the presence of CB7, as tested against four pathogenic bacteria; highest activity has been found towards B. cereus and E. coli, and lower activity towards S. aureus and S. typhi. The antibacterial activity of two additional second-generation fluoroquinones, i.e., norfloxacin and ofloxacin, has also been investigated in the absence as well as the presence of CB7 and compared with that of DOFL. In case of all drugs, the minimum inhibitory concentration (MIC) was reduced 3-5 fold in the presence of CB7. The extended shelf-life (antibacterial activity over time) of the fluoroquinone drugs in the presence of CB7, irrespective of four types of bacteria, can be attributed to the enhanced photostability of their CB7 complexes, which can act as better antibiotics with a longer expiry date than uncomplexed DOFL.

| S-EPMC6141578 | biostudies-literature

Synthesis and self-assembly processes of monofunctionalized cucurbit[7]uril.

Project description:We present a building-block approach toward functionalized CB[7] derivatives by the condensation of methylene-bridged glycoluril hexamer 1 and glycoluril bis(cyclic ethers) 2 and 12. The CB[7] derivatives Me2CB[7] and CyCB[7] are highly soluble in water (264 mM and 181 mM, respectively). As a result of the high intrinsic solubility of Me2CB[7], it is able to solubilize the insoluble benzimidazole drug albendazole. The reaction of hexamer 1 with glycoluril derivative 12, which bears a primary alkyl chloride group, gives CB[7] derivative 18 in 16% isolated yield. Compound 18 reacts with NaN3 to yield azide-substituted CB[7] 19 in 81% yield, which subsequently undergoes click reaction with propargylammonium chloride (21) to yield CB[7] derivative 20 in 95% yield, which bears a covalently attached triazolyl ammonium group along its equator. The results of NMR spectroscopy ((1)H, variable-temperature, and DOSY) and electrospray mass spectrometry establish that 20 undergoes self-assembly to form a cyclic tetrameric assembly (204) in aqueous solution. CB[7] derivatives bearing reactive functional groups (e.g., N3, Cl) are now available for incorporation into more complex functional systems.

| S-EPMC3510339 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data