scholarly journals Carbazole-Based Colorimetric Anion Sensors

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3205
Author(s):  
Krystyna Maslowska-Jarzyna ◽  
Maria L. Korczak ◽  
Jakub A. Wagner ◽  
Michał J. Chmielewski
Keyword(s):  
Hydrogen Bond ◽  
Visible Region ◽  
Building Blocks ◽  
Anion Transport ◽  
Anion Binding ◽  
Anion Receptors ◽  
Binding Studies ◽  
Anion Sensor ◽  
Anion Sensors ◽  
Anion Interaction

Owing to their strong carbazole chromophore and fluorophore, as well as to their powerful and convergent hydrogen bond donors, 1,8-diaminocarbazoles are amongst the most attractive and synthetically versatile building blocks for the construction of anion receptors, sensors, and transporters. Aiming to develop carbazole-based colorimetric anion sensors, herein we describe the synthesis of 1,8-diaminocarbazoles substituted with strongly electron-withdrawing substituents, i.e., 3,6-dicyano and 3,6-dinitro. Both of these precursors were subsequently converted into model diamide receptors. Anion binding studies revealed that the new receptors exhibited significantly enhanced anion affinities, but also significantly increased acidities. We also found that rear substitution of 1,8-diamidocarbazole with two nitro groups shifted its absorption spectrum into the visible region and converted the receptor into a colorimetric anion sensor. The new sensor displayed vivid color and fluorescence changes upon addition of basic anions in wet dimethyl sulfoxide, but it was poorly selective; because of its enhanced acidity, the dominant receptor-anion interaction for most anions was proton transfer and, accordingly, similar changes in color were observed for all basic anions. The highly acidic and strongly binding receptors developed in this study may be applicable in organocatalysis or in pH-switchable anion transport through lipophilic membranes.

scholarly journals Solution and Solid State Studies of Urea Derivatives of DITIPIRAM Acting as Powerful Anion Receptors

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1788
Author(s):  
Patryk Niedbała ◽  
Kajetan Dąbrowa ◽  
Agnieszka Cholewiak-Janusz ◽  
Janusz Jurczak
Keyword(s):  
Anion Binding ◽  
Solvent Mixtures ◽  
Anion Receptors ◽  
Dft Studies ◽  
Binding Studies ◽  
Urea Derivatives ◽  
X Ray ◽  
Molecular Receptors ◽  
Guest System ◽  
Derivatives Of

Herein, we present the synthesis and anion binding studies of a family of homologous molecular receptors 4–7 based on a DITIPIRAM (8-propyldithieno-[3,2-b:2′,3′-e]-pyridine-3,5-di-amine) platform decorated with various urea para-phenyl substituents (NO2, F, CF3, and Me). Solution, X-ray, and DFT studies reveal that the presented host–guest system offers a convergent array of four urea NH hydrogen bond donors to anions allowing the formation of remarkably stable complexes with carboxylates (acetate, benzoate) and chloride anions in solution, even in competitive solvent mixtures such as DMSO-d6/H2O 99.5/0.5 (v/v) and DMSO-d3/MeOH-d3 9:1 (v/v). The most effective derivatives among the series turned out to be receptors 5 and 6 containing electron-withdrawing F- and -CF3para-substituents, respectively.

scholarly journals Investigating the Influence of Steric Hindrance on Selective Anion Transport

Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1278 ◽  
Author(s):  
Laura Jowett ◽  
Angela Ricci ◽  
Xin Wu ◽  
Ethan Howe ◽  
Philip Gale
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Steric Hindrance ◽  
Chloride Transport ◽  
Anion Transport ◽  
Anion Binding ◽  
Chloride Binding ◽  
Anion Receptors ◽  
Flip Flop ◽  
Anion Transporters

A series of symmetrical and unsymmetrical alkyl tren based tris-thiourea anion transporters were synthesised and their anion binding and transport properties studied. Overall, increasing the steric bulk of the substituents resulted in improved chloride binding and transport abilities. Including a macrocycle in the scaffold enhanced the selectivity of chloride transport in the presence of fatty acids, by reducing the undesired H+ flux facilitated by fatty acid flip-flop. This study demonstrates the benefit of including enforced steric hindrance and encapsulation in the design of more selective anion receptors.

scholarly journals Selective anion transport mediated by strap-extended calixpyrroles

2020 ◽  
Vol 24 (01n03) ◽  
pp. 473-479 ◽  
Author(s):  
Harriet J. Clarke ◽  
Xin Wu ◽  
Mark E. Light ◽  
Philip A. Gale
Keyword(s):  
Fatty Acids ◽  
Chloride Transport ◽  
Anion Transport ◽  
Anion Binding ◽  
Anion Receptors ◽  
Future Design ◽  
Anion Transporters ◽  
Head Groups ◽  
Proton Leakage ◽  
Autophagy Inhibition

Synthetic anion receptors that facilitate transmembrane chloride transport are of interest as potential therapeutic agents for cancer and cystic fibrosis. Transporters selective for chloride over protons are desired for therapeutic applications to avoid autophagy inhibition and cytotoxicity. Examples of such compounds are rare because the majority of anion transporters can interact with the carboxylate head groups of fatty acids leading to proton leakage. In this paper, we report the synthesis, anion binding and transmembrane anion transport properties of two novel bis-triazole-functionalized calixpyrroles with extended straps, and compare them to previously reported shorter-strap analogues known to exhibit high Cl [Formula: see text] H[Formula: see text] selectivity. We demonstrate improved chloride transport activities of the strap-extended compounds that likely benefit from increased lipophilicity, and reduced Cl [Formula: see text] H[Formula: see text] selectivity due to the larger anion binding cavities facilitating interaction with fatty acids. The results are instructive for future design of ideal anion transporters with potent activity and high selectivity against proton leakage.

Synthesis and anion binding properties of porphyrins and related compounds

2016 ◽  
Vol 20 (08n11) ◽  
pp. 950-965 ◽  
Author(s):  
Flávio Figueira ◽  
João M.M. Rodrigues ◽  
Andreia A.S. Farinha ◽  
José A.S. Cavaleiro ◽  
João P.C. Tomé
Keyword(s):  
Anion Recognition ◽  
Anion Binding ◽  
Anion Receptors ◽  
Binding Studies ◽  
Binding Properties ◽  
Related Research ◽  
Expanded Porphyrins ◽  
Recent Developments ◽  
Related Compounds

Over the last two decades the preparation of pyrrole-based receptors for anion recognition has attracted considerable attention. In this regard porphyrins, phthalocyanines and expanded porphyrins have been used as strong and selective receptors while the combination of those with different techniques and materials can boost their applicability in different applications as chemosensors and extracting systems. Improvements in the field, including the synthesis of this kind of compounds, can contribute to the development of efficient, cheap, and easy-to-prepare anion receptors. Extensive efforts have been made to improve the affinity and selectivity of these compounds and the continuous expansion of related research makes this chemistry even more promising. In this review, we summarize the most recent developments in anion binding studies while outlining the strategies that may be used to synthesize and functionalize these type of macrocycles.

Sensing anions on surfaces: tethering triazolium based anion receptors to polymer resins

RSC Advances ◽  
2016 ◽  
Vol 6 (40) ◽  
pp. 33880-33887 ◽  
Author(s):  
S. Byrne ◽  
K. M. Mullen
Keyword(s):  
Chemical Reactivity ◽  
Mas Nmr ◽  
Anion Binding ◽  
Anion Receptors ◽  
Surface Characterisation ◽  
Binding Properties ◽  
Good Surface ◽  
Anion Sensors ◽  
Characterisation Techniques

Herein we report the development of a new series of surface bound triazolium based anion sensors. Differences in the chemical reactivity and anion binding properties were observed; highlighting the need for good surface characterisation techniques such as HR MAS NMR.

Synthesis of Quinoline-Based Anion Receptors and Preliminary Anion Binding Studies with Selected Derivatives

Synthesis ◽  
2014 ◽  
Vol 47 (06) ◽  
pp. 861-870
Author(s):  
Markus Albrecht ◽  
Zhanhu Sun ◽  
Fangfang Pan ◽  
Michel Waringo
Keyword(s):  
Anion Binding ◽  
Anion Receptors ◽  
Binding Studies

New Polydentate Macrocyclic Ligands of Hybrid Amine-Imine and Amide-Imine Types as Artificial Anion Receptors. Synthesis and Study of Anion Binding.

ChemInform ◽  
2005 ◽  
Vol 36 (52) ◽  
Author(s):  
E. A. Katayev ◽  
G. D. Pantos ◽  
V. M. Lynch ◽  
J. L. Sessler ◽  
M. D. Reshetova ◽  
...  
Keyword(s):  
Macrocyclic Ligands ◽  
Anion Binding ◽  
Anion Receptors

The red cell band 3 protein: its role in anion transport

1982 ◽  
Vol 299 (1097) ◽  
pp. 497-507 ◽  
Keyword(s):  
Binding Sites ◽  
Band 3 ◽  
Anion Transport ◽  
Anion Binding ◽  
Hydrophobic Residues ◽  
Ping Pong ◽  
Hydrophilic Residues ◽  
Aqueous Core ◽  
Positively Charged

Studies of anion transport across the red blood cell membrane fall generally into two categories: (1) those concerned with the operational characterization of the transport system, largely by kinetic analysis and inhibitor studies; and (2) those concerned with the structure of band 3, a transmembrane peptide identified as the transport protein. The kinetics are consistent with a ping-pong model in which positively charged anion-binding sites can alternate between exposure to the inside and outside compartments but can only shift one position to the other when occupied by an anion. The structural studies on band 3 indicate that only 60 % of the peptide is essential for transport. That particular portion is in the form of a dimer consisting of an assembly of membrane-crossing strands (each monomer appears to cross at least five times). The assembly presents its hydrophobic residues toward the interior of the bilayer, but its hydrophilic residues provide an aqueous core. The transport involves a small conformational change in which an anion-binding site (involving positively charged residues) can alternate between positions that are topologically in and topologically out.

scholarly journals The human erythrocyte anion transport protein, band 3. Characterization of exofacial alkaline titratable groups involved in anion binding/translocation.

1992 ◽  
Vol 100 (2) ◽  
pp. 301-339 ◽  
Author(s):  
P J Bjerrum
Keyword(s):  
Ionic Strength ◽  
Binding Site ◽  
Transport System ◽  
Human Erythrocyte ◽  
Binding Constant ◽  
Anion Transport ◽  
High Ionic Strength ◽  
Anion Binding ◽  
Asymmetry Factor ◽  
Sensitive Group

Chloride self-exchange across the human erythrocyte membrane at alkaline extracellular pH (pHO) and constant neutral intracellular pH (pH(i)) can be described by an exofacial deprotonatable reciprocating anion binding site model. The conversion of the transport system from the neutral to the alkaline state is related to deprotonation of a positively charged ionic strength- and substrate-sensitive group. In the absence of substrate ions ([ClO] = 0) the group has a pK of approximately 9.4 at constant high ionic strength (equivalent to approximately 150 mM KCl) and a pK of approximately 8.7 at approximately zero ionic strength. The alkaline ping-pong system (examined at constant high ionic strength) demonstrates outward recruitment of the binding sites with an asymmetry factor of approximately 0.2, as compared with the inward recruitment of the transport system at neutral pHO with an asymmetry factor of approximately 10. The intrinsic half-saturation constant for chloride binding, with [Cli] = [Clo], increased from approximately 30 mM at neutral to approximately 110 mM at alkaline pHO. The maximal transport rate was a factor of approximately 1.7 higher at alkaline pHO. This increase explains the stimulation of anion transport, the "modifier hump," observed at alkaline pHO. The translocation of anions at alkaline pHO was inhibited by deprotonation of another substrate-sensitive group with an intrinsic pK of approximately 11.3. This group together with the group with a pK of approximately 9.4 appear to form the essential part of the exofacial anion binding site. The effect of extracellular iodide inhibition on chloride transport as a function of pHO could, moreover, be simulated if three extracellular iodide binding constants were included in the model: namely, a competitive intrinsic iodide binding constant of approximately 1 mM in the neutral state, a self-inhibitor binding constant of approximately 120 mM in the neutral state, and a competitive intrinsic binding constant of approximately 38 mM in the alkaline state.

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