Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Diasteroselective multi-component assemblies from dynamic covalent imine condensation and metal-coordination chemistry: mechanism and narcissistic stereochemistry self-sorting.

ABSTRACT: Self-assembly of a modified tris(2-pyridylmethyl)amine TPMA ligand, zinc(ii) or cobalt(ii) ions, and amino acids have been used effectively as stereo dynamic optical probes for the determination of the enantiomeric excess of free amino acids either using Electronic or Vibrational Circular Dichroism (CD and VCD). Herein, we report the mechanistic and stereochemical study of the self-assembly process which reveals a complex equilibrium in solution where even small variations in the experimental conditions can profoundly affect the final products of the reaction. In particular, variation on the metal stoichiometry switch give rises to an entirely enantio narcissistic self-assembly of the structure.

SUBMITTER: Badetti E

PROVIDER: S-EPMC9080712 | biostudies-literature | 2018 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Diasteroselective multi-component assemblies from dynamic covalent imine condensation and metal-coordination chemistry: mechanism and narcissistic stereochemistry self-sorting.

Badetti Elena E Carmo Dos Santos Nadia Alessandra NA Scaramuzzo Francesca A FA Bravin Carlo C Wurst Klaus K Licini Giulia G Zonta Cristiano C

RSC advances 20180529 35

Self-assembly of a modified tris(2-pyridylmethyl)amine TPMA ligand, zinc(ii) or cobalt(ii) ions, and amino acids have been used effectively as stereo dynamic optical probes for the determination of the enantiomeric excess of free amino acids either using Electronic or Vibrational Circular Dichroism (CD and VCD). Herein, we report the mechanistic and stereochemical study of the self-assembly process which reveals a complex equilibrium in solution where even small variations in the experimental co ...[more]

PMID: 35540993

Similar Datasets

Narcissistic, Integrative, and Kinetic Self-Sorting within a System of Coordination Cages.

Project description:Many useful principles of self-assembly have been elucidated through studies of systems where multiple components combine to create a single structure. More complex systems, where multiple product structures self-assemble in parallel from a shared set of precursors, are also of great interest, as biological systems exhibit this behavior. The greater complexity of such systems leads to an increased likelihood that discrete species will not be formed, however. Here we show how the kinetics of self-assembly govern the formation of multiple metal-organic architectures from a mixture of five building blocks, preventing the formation of a discrete structure of intermediate size. By varying ligand symmetry, denticity, and orientation, we explore how five distinct polyhedra-a tetrahedron, an octahedron, a cube, a cuboctahedron, and a triangular prism-assemble in concert around CoII template ions. The underlying rules dictating the organization of assemblies into specific shapes are deciphered, explaining the formation of only three discrete entities when five could form in principle.

| S-EPMC7304868 | biostudies-literature

Designing narcissistic self-sorting terpyridine moieties with high coordination selectivity for complex metallo-supramolecules.

Project description:Coordination-driven self-assembly is a powerful approach for the construction of metallosupramolecules, but designing coordination moieties that can drive the self-assembly with high selectivity and specificity remains a challenge. Here we report two ortho-modified terpyridine ligands that form head-to-tail coordination complexes with Zn(II). Both complexes show narcissistic self-sorting behaviour. In addition, starting from these ligands, we obtain two sterically congested multitopic ligands and use them to construct more complex metallo-supramolecules hexagons. Because of the non-coaxial structural restrictions in the rotation of terpyridine moieties, these hexagonal macrocycles can hierarchically self-assemble into giant cyclic nanostructures via edge-to-edge stacking, rather than face-to-face stacking. Our design of dissymmetrical coordination moieties from congested coordination pairs show remarkable self-assembly selectivity and specificity.

| S-EPMC9814872 | biostudies-literature

Sterics and Hydrogen Bonding Control Stereochemistry and Self-Sorting in BINOL-Based Assemblies.

Project description:Here we demonstrate how the hydrogen-bonding ability of a BINOL-based dialdehyde subcomponent dictated the stereochemical outcome of its subsequent self-assembly into one diastereomeric helicate form when bearing free hydroxy groups, and another in the case of its methylated congener. The presence of methyl groups also altered the self-sorting behavior when mixed with another, short linear dialdehyde subcomponent, switching the outcome of the system from narcissistic to integrative self-sorting. In all cases, the axial chirality of the BINOL building block also dictated helicate metal center handedness during stereospecific self-assembly. A new family of stereochemically pure heteroleptic helicates were thus prepared using the new knowledge gained. We also found that switching from FeII to ZnII, or the incorporation of a longer linear ligand, favored heteroleptic structure formation.

| S-EPMC8227477 | biostudies-literature

Examination of the Dynamic Covalent Chemistry of [2 + 3]-Imine Cages.

Project description:The synthesis of shape-persistent organic cage compounds by the formation of imine bonds opens the possibility to realize cages of different sizes, geometries, topologies, and functions. It is generally assumed that the imine bond is rather chemically labile allowing a self-correction mechanism until thermodynamic equilibrium is reached, which is often the case if a cage is formed. However, there are some contradictory experimental data to this assumption. To get a deeper insight into the imine bond dynamics of covalent organic cages, we studied the formation and exchange of both dialdehydes and triamines of two different [2 + 3] imine cages with the aid of a deuterated dialdehyde molecular building block.

| S-EPMC7659045 | biostudies-literature

Stereochemistry and Reactivity of the HPA-Imine Mannich Intermediate.

Project description:Homophthalic anhydride (HPA) typically reacts rapidly with benzalimines to afford the formal [4+2] adduct, a 1,2,3,4-tetrahydroisoquinolin-1-one-4-carboxylic acid. The stereochemical outcome of this reaction is consistent with an open transition state comprising an iminium species and enolized HPA, leading to a short-lived amino-anhydride intermediate. In the case of N-tert-butylbenzalimine, this Mannich-type intermediate, which would normally cyclize at low temperature to a single isomer of the delta-lactam, is intercepted by base treatment to afford beta-lactam products. A pathway featuring ketene formation followed by ring closure is implicated.

| S-EPMC5737782 | biostudies-literature

Dynamic covalent self-assembly and self-sorting processes in the formation of imine-based macrocycles and macrobicyclic cages.

Project description:Investigating the self-assembly and self-sorting behaviour of dynamic covalent organic architectures makes possible the parallel generation of multiple discrete products in a single one pot procedure. We here report the self-assembly of covalent organic macrocycles and macrobicyclic cages from dialdehyde and polyamine components via multiple [2 + 2] and [3 + 2] polyimine condensations. Furthermore, component self-sorting processes have been monitored within the dynamic covalent libraries formed by these macrocycles and macrobicyclic cages. The progressive assembly of the final structures involves intermediates which undergo component selection and self-correction to generate the final thermodynamic constituents. The homo-self-sorting observed seems to involve entropic factors, as the homoleptic species present a higher symmetry than the competing heteroleptic ones. This study not only emphasizes the importance of an adequate design of the components of complex self-sorting systems, but also verifies the conjecture that systems of higher complexity may generate simpler outputs through the operation of competitive self-sorting.

| S-EPMC10284075 | biostudies-literature

Organogelating and narcissistic self-sorting behaviour of non-preorganized oligoamides.

Project description:Several series of structurally flexible, non-preorganized oligoamides with carboxylic acid, hydride, N-propargyl amide and N-propyl amide end groups were synthesized and characterized. They were found to be strong organogelators for aromatic solvents. Both the number and density of the amide units, and the nature of the end group were found to influence the gel strength as well as the kinetics of gel formation. Oligomers with a higher number and density of amide units were found to form stronger gels. Rather unexpectedly, a slight change of the end group could significantly affect the enthalpy and entropy of formation of the resulting self-assembly. Oligomers with the N-propargyl amide end group were found to be kinetically trapped in the melted state, which devoid them of forming crystalline zone upon cooling. On the other hand, the corresponding saturated N-propyl amide analog did not show the same effect. Upon mixing of these oligomers, narcissistic self-sorting could be observed in both the wet gel and xerogel states if (i) the difference in the number of amide units is greater than one or (ii) the amide unit densities are different. A semi-quantitative assessment of the extent of self-sorting could be achieved by constructing the corresponding phase diagram of the mixed gel systems. It is concluded that narcissistic self-sorting does not just prevail in mixtures making up of structurally different molecules, but appears to be fairly general even in mixtures of structurally similar molecular homologs.

| S-EPMC6457331 | biostudies-literature

Surface Chemistry of a Halogenated Borazine: From Supramolecular Assemblies to a Random Covalent BN-Substituted Carbon Network.

Project description:The on-surface synthesis strategy has emerged as a promising route for fabricating well-defined two-dimensional (2D) BN-substituted carbon nanomaterials with tunable electronic properties. This approach relies on specially designed precursors and requires a thorough understanding of the on-surface reaction pathways. It promises precise structural control at the atomic scale, thus complementing chemical vapor deposition (CVD). In this study, we investigated a novel heteroatomic precursor, tetrabromoborazine, which incorporates a BN core and an OH group, on Ag(111) using low temperature scanning tunnelling microscopy/spectroscopy (LT-STM/STS) and X-ray photoelectron spectroscopy (XPS). Through sequential temperature-induced reactions involving dehalogenation and dehydrogenation, distinct tetrabromoborazine derivatives were produced as reaction intermediates, leading to the formation of specific self-assemblies. Notably, the resulting intricate supramolecular structures include a chiral kagomé lattice composed of molecular dimers exhibiting a unique electronic signature. The final product obtained was a random covalent carbon network with BN-substitution and embedded oxygen heteroatoms. Our study offers valuable insights into the significance of the structure and functionalization of BN precursors in temperature-induced on-surface reactions, which can help future rational precursor design. Additionally, it introduces complex surface architectures that offer a high areal density of borazine cores.

| S-EPMC11632406 | biostudies-literature

Tracking distinct RNA populations using efficient and reversible covalent chemistry

Project description:We describe a chemical method to label and purify 4-thiouridine (s4U) -containing RNA. We demonstrate that methanethiolsulfonate (MTS) reagents form disulfide bonds with s4U more efficiently than the commonly used HPDP-biotin, leading to higher yields and less biased enrichment. This increase in efficiency allowed us to use s4U-labeling to study global microRNA (miRNA) turnover in proliferating cultured human cells without perturbing global miRNA levels or the miRNA processing machinery. This improved chemistry will enhance methods that depend on tracking different populations of RNA such as 4-thiouridine-tagging to study tissue-specific transcription and dynamic transcriptome analysis (DTA) to study RNA turnover. s4U metabolic labeling of RNA in 293T cells, followed by biochemical enrichment of labeled RNA with two biotinylation reagents, RNAs >200nt and miRNAs in separate experiments

2015-09-03 | E-GEOD-60988 | biostudies-arrayexpress

Probing the Solubility of Imine-Based Covalent Adaptable Networks.

Project description:Covalent adaptable networks (CANs) are polymer materials that are covalently cross-linked via dynamic covalent bonds. The cross-linked polymer network is generally expected to be insoluble, as is seen for traditional thermosets. However, in recent years, it has become apparent that-under certain conditions-both dissociative and associative CANs can be dissolved in a good solvent. For some applications (e.g., those that require long-term (chemical) stability), the solubility of CANs can be problematic. However, many forget that (selective) solubility of CANs can also be applied advantageously, for example, in recycling or modification of the materials. In this work, we provide results and insights related to the tunable solubility of imine-based CANs. We observed that selected CANs could be fully dissolved in a good solvent without observing dissociation of imines. Only in an acidic environment (partial) dissociation of imines was observed, which could be reverted to the associated state by addition of a base. By adjusting the network composition, we were able to either facilitate or hamper solubility as well as control the size of the dissolved particles. DLS showed that the size of dissolved polymer particles decreased at lower concentrations. Similarly, decreasing cross-linking density resulted in smaller particles. Last, we showed that we could use the solubility of the CANs as a means for chemical recycling and postpolymerization modification. The combination of our studies with existing literature provides a better understanding of the solubility of CANs and their applications as recyclable thermosets.

| S-EPMC10788871 | 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