The role of chiral counterions on the attraction and self-assembly of chiral PdL metal organic cages (MOCs) with NO being the original counterion is studied by laser light scattering and isothermal titration calorimetry. Nitrates can trigger the self-assembly of macrocationic PdL into hollow spherical blackberry-type supramolecular structures counterion-mediated attraction. Although chiral counteranions, such as -(-butoxycarbonyl)-alanine (Boc-Ala), have weaker interaction with the MOCs compared to NO, they can induce different assembly behaviors between two enantiomeric MOCs by inhibiting the MOC-nitrate binding and weakening the interaction between them. The d-counterions are capable of selectively suppressing and slowing down the assembly of l-MOCs and also considerably decreasing their assembly size due to the much weaker MOC-nitrate interaction. The same scenario is observed for l-counterions when interacting with the d-MOCs. This study unveils the role of weakly associated chiral counterions on the central chiral macroions, especially their supramolecular structure formation, and provides additional evidence on the mechanism of the homochirality phenomenon.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.jpcb.0c07424 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
In-Cage Recombination Facilitates the Enantioselective Organocatalytic [1,2]-Rearrangement of Allylic Ammonium Ylides.
J Am Chem Soc
December 2024
EaStCHEM, School of Chemistry, University of St Andrews, North Haugh, St. Andrews, KY16 9ST, U.K.
The [1,2]-rearrangement of allylic ammonium ylides is traditionally observed as a competitive minor pathway alongside the thermally allowed [2,3]-sigmatropic rearrangement. Concerted [1,2]-rearrangements are formally forbidden, with these processes believed to proceed through homolytic C-N bond fission of the ylide, followed by radical-radical recombination. The challenges associated with developing a catalytic enantioselective [1,2]-rearrangement of allylic ammonium ylides therefore lie in biasing the reaction pathway to favor the [1,2]-reaction product, alongside controlling a stereoselective radical-radical recombination event.
View Article and Find Full Text PDFDetermination of the Effective Charge Numbers and Ionic Mobilities of Single Isomer and Randomly Highly Sulfated Cyclodextrins by Capillary Isotachophoresis and Zone Electrophoresis.
Electrophoresis
November 2024
Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, Czech Republic.
Article Synopsis
- Sulfated cyclodextrins are negatively charged molecules used in capillary electrophoresis for separating chiral compounds, but their effective charge can be lower than expected due to counterion binding.
- This study used capillary isotachophoresis and capillary zone electrophoresis to measure the effective charge numbers and ionic mobilities of two types of sulfated cyclodextrins: single isomer and randomly highly sulfated.
- Results showed that while the effective charge numbers of single isomer sulfated cyclodextrins closely matched their sulfate groups, the randomly highly sulfated versions had their effective charges reduced by 22.2%-27.8%, leading to lower ionic mobilities for the single isomer
When Chirality Makes the Difference: The Case of Novel Enantiopure -Heterocyclic Carbene-Gold and -Silver Complexes.
Molecules
November 2024
Department of Chemistry and Biology, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, Italy.
-heterocyclic carbene (NHC)-gold and -silver complexes have attracted the interest of the scientific community because of their multiple applications and their versatility in being chemically modified in order to improve their biological properties. However, most of these complexes contain one or more chiral centers, and have been obtained and studied as racemic mixture. In particular, concerning the interesting biological and medicinal properties, many questions about how the chirality may influence these properties still remain unanswered.
View Article and Find Full Text PDFUnderstanding ketone hydrogenation catalysis with anionic iridium(iii) complexes: the crucial role of counterion and solvation.
Chem Sci
December 2024
CNRS, LCC (Laboratoire de Chimie de Coordination), Université de Toulouse, UPS, INPT 205 Route de Narbonne, BP 44099, F-31077 Toulouse Cedex 4 France +33-561553003 +33-561333174.
Catalytic asymmetric hydrogenation of ketones is an important approach to prepare valuable chiral alcohols. Understanding how transition metals promote these reactions is key to the rational design of more active, selective and sustainable catalysts. A highly unusual mechanism for asymmetric hydrogenation of acetophenone catalysed by an anionic Ir hydride system, including a strong counterion dependence on catalyst activity, is explored and rationalised here.
View Article and Find Full Text PDFChiral Supramolecular Proton Conductors: Harnessing Highly Charged Zirconium-Amino Acid Oxo-Clusters.
Inorg Chem
December 2024
Departamento de Química Inorgánica, Facultad de Ciencia y Tecnología, Universidad del País Vasco, UPV/EHU, Apartado 644, E-48080 Bilbao, Spain.
Incorporation of amino acid capping molecules (alanine (Ala), methionine (Met), phenylalanine (Phe), tryptophan (Trp), tyrosine (Tyr), and valine (Val)) in their zwitterionic form into archetypal [Zr(μ-O)(μ-OH)] clusters creates supramolecular frameworks in which the assembly of these highly charged discrete units with chloride counterions provides a unique combination of porosity, chirality, and proton conductivity. The supramolecular frameworks assembled from these cluster entities (i.e.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!