scholarly journals Novel fluorescent probes for the fluoride anion based on hydroxy-substituted perylene tetra-(alkoxycarbonyl) derivatives

RSC Advances ◽  
2018 ◽  
Vol 8 (25) ◽  
pp. 14084-14091 ◽  
Author(s):  
Fengxia Zhang ◽  
Yunlong Zhao ◽  
Yanhui Chi ◽  
Yongshan Ma ◽  
Tianyi Jiang ◽  
...  
Keyword(s):  
Fluorescent Probes ◽  
Visual Detection ◽  
Fluoride Anion ◽  
Detection Experiment ◽  
H Nmr ◽  
Nmr Titrations

The fluoride anion (F−) sensing abilities of two fluorescent probes based on hydroxy-substituted perylene tetra-(alkoxycarbonyl) derivatives were studied through visual detection experiment, UV-Vis, fluorescence, and 1H NMR titrations.

scholarly journals Study of the coordination of quinuclidine to a chiral zinc phthalocyanine dimer

2016 ◽  
Vol 20 (08n11) ◽  
pp. 1224-1232 ◽  
Author(s):  
Nelson Giménez-Agulló ◽  
Gemma Aragay ◽  
José Ramón Galán-Mascarós ◽  
Pablo Ballester
Keyword(s):  
Chemical Exchange ◽  
Variable Temperature ◽  
Exchange Process ◽  
Zinc Phthalocyanine ◽  
Hydrogen Atoms ◽  
Dimerization Constant ◽  
H Nmr ◽  
Dimerization Process ◽  
Nmr Titrations ◽  
Millimolar Concentration

We attempted the calculation of an accurate equilibrium constant for the dimerization process of enantiomerically pure Zn-1 using UV-vis dilution experiments. At millimolar concentration Zn-1 is involved in a chemical exchange process between its monomeric and dimeric state that is slow on the 1H NMR timescale. We performed variable-temperature 1H NMR experiments in CDCl3 solution to determine the dimerization constant value at different temperatures and performed a van’t Hoff plot to derive the thermodynamic parameters of the process. The calculated thermodynamic data revealed that the dimerization process is entropy-driven and enthalpically opposed. We also probed the coordination of quinuclidine, 1-azabicyclo[2.2.2]octane, 2, to the Zn-1 using UV-vis and 1H NMR titrations in CDCl3 solution. At micromolar concentration the Zn-1 exclusively exists in solution as a monomer and forms a simple 1:1, [Formula: see text], complex with quinuclidine having a stability constant of [Formula: see text]([Formula: see text]) [Formula: see text] 106 M[Formula: see text]. On the other hand, the 1H NMR titrations carried out at 298 K and at millimolar concentration showed that Zn-1 was present in solution as the dimer and formed 1:2, [Formula: see text], and 2:2, [Formula: see text] complexes by coordination to 2. In addition, the 1:1 complex, [Formula: see text] showed a reduced dimerization constant compared to the uncoordinated parent monomer Zn-1. At high quinuclidine concentration, the 1:1 complex, [Formula: see text], derived from the coordinated dimer dissociation was also detected. The 1H NMR spectra of the titrations displayed separate signals for some hydrogen atoms of the Zn-phthalocyanine in each one of the four species. Remarkably, the chemical exchange processes involving free and bound quinuclidine in the monomeric and dimeric complexes showed different kinetics on the NMR timescale.

scholarly journals Novel acridine-based thiosemicarbazones as ‘turn-on' chemosensors for selective recognition of fluoride anion: a spectroscopic and theoretical study

2018 ◽  
Vol 5 (7) ◽  
pp. 180646 ◽  
Author(s):  
Ibanga Okon Isaac ◽  
Iqra Munir ◽  
Mariya al-Rashida ◽  
Syed Abid Ali ◽  
Zahid Shafiq ◽  
...  
Keyword(s):  
Density Functional ◽  
Theoretical Study ◽  
Fluoride Anion ◽  
Metal Fluoride ◽  
Visible Absorption ◽  
Functional Theory ◽  
H Nmr ◽  
Tetrabutylammonium Fluoride ◽  
Uv Visible ◽  
Nickel Fluoride

New thiosemicarbazide-linked acridines 3a–c were prepared and investigated as chemosensors for the detection of biologically and environmentally important anions. The compounds 3a–c were found selective for fluoride (F − ) with no affinity for other anions, i.e. − OAc, Br − , I − , HSO 4 − , SO 4 2− , PO 4 3− , ClO 3 − , ClO 4 − , CN − and SCN − . Further, upon the gradual addition of a fluoride anion (F − ) source (tetrabutylammonium fluoride), a well-defined change in colour of the solution of probes 3a–c was observed. The anion-sensing process was studied in detail via UV–visible absorption, fluorescence and 1 H-NMR experiments. Moreover, during the synthesis of acridine probes 3a–c nickel fluoride (NiF 2 ), a rarely explored transition metal fluoride salt, was used as the catalyst. Theoretical studies via density functional theory were also carried out to further investigate the sensing and anion (F − ) selectivity pattern of these probes.

Several fluorescent probes based on hemicyanine for the detection of SO2 derivatives

2018 ◽  
Vol 10 (38) ◽  
pp. 4695-4701 ◽  
Author(s):  
Xue Li ◽  
Di Jin ◽  
Yuchao Du ◽  
Ying Liu ◽  
Bowei Wang ◽  
...  
Keyword(s):  
Fluorescent Probes ◽  
Rapid Detection ◽  
Visual Detection

Three new fluorescent probes for sensitive, selective and rapid detection of SO2 derivatives and visual detection of SO2 gas.

scholarly journals Complexation of 2,6-helic[6]arene and its derivatives with 1,1′-dimethyl-4,4′-bipyridinium salts and protonated 4,4'-bipyridinium salts: an acid–base controllable complexation

2019 ◽  
Vol 15 ◽  
pp. 1795-1804 ◽  
Author(s):  
Jing Li ◽  
Qiang Shi ◽  
Ying Han ◽  
Chuan-Feng Chen
Keyword(s):  
Association Constants ◽  
The Other ◽  
Acid Base ◽  
Polar Solvents ◽  
X Ray ◽  
H Nmr ◽  
Hydrogen Bonding Interactions ◽  
Acids And Bases ◽  
Multiple Hydrogen Bonding ◽  
Nmr Titrations

2,6-Helic[6]arene and its derivatives were synthesized, and their complexation with 1,1′-dimethyl-4,4′-bipyridinium and protonated 4,4'-bipyridinium salts were investigated in detail. It was found that the helic[6]arene and its derivatives could all form 1:1 complexes with both 1,1′-dimethyl-4,4'-bipyridinium salts and protonated 4,4'-bipyridinium salts in solution and in the solid state. Especially, the helic[6]arene and its derivatives containing 2-hydroxyethoxy or 2-methoxyethoxy groups exhibited stronger complexation with the guests than the other helic[6]arene derivatives for the additional multiple hydrogen bonding interactions between the hosts and the guests, which were evidenced by 1H NMR titrations, X-ray crystal structures and DFT calculations. Moreover, it was also found that the association constants (K a) of the complexes could be significantly enhanced with larger counteranions of the guests and in less polar solvents. Furthermore, the switchable complexation between the helic[6]arene and protonated 4,4'-bipyridinium salt could be efficiently controlled by acids and bases.

Recognition of bio-relevant dicarboxylate anions by an azacalix[2]arene[2]triazine derivative decorated with urea moieties

2015 ◽  
Vol 13 (10) ◽  
pp. 3070-3085 ◽  
Author(s):  
Miguel M. Santos ◽  
Igor Marques ◽  
Sílvia Carvalho ◽  
Cristina Moiteiro ◽  
Vítor Félix
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Binding Affinity ◽  
H Nmr ◽  
Triazine Derivative ◽  
Wide Range ◽  
Dynamics Simulations ◽  
Nmr Titrations

The binding affinity of a dichlorocalix[2]arene[2]triazine based bis-urea azamacrocycle was investigated towards a wide range of bio-relevant dicarboxylate anions by a combination of 1H NMR titrations in CDCl3 and molecular dynamics simulations.

scholarly journals Binding Between Cyclohexanohemicucurbit[n]urils and Polar Organic Guests

2021 ◽  
Vol 9 ◽  
Author(s):  
Lukas Ustrnul ◽  
Tatsiana Burankova ◽  
Mario Öeren ◽  
Kristina Juhhimenko ◽  
Jenni Ilmarinen ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Atomic Charge ◽  
Hydrogen Bond Donor ◽  
H Nmr ◽  
Partial Charges ◽  
Potential Applications ◽  
Halogenated Solvents ◽  
Organic Guests ◽  
Nmr Titrations ◽  
Formation Of Complexes

Inherently chiral, barrel-shaped, macrocyclic hosts such as cyclohexanohemicucurbit[n]urils (cycHC[n]) bind zinc porphyrins and trifluoroacetic acid externally in halogenated solvents. In the current study, we tested a set of eighteen organic guests with various functional groups and polarity, namely, thiophenols, phenols, and carboxylic and sulfonic acids, to identify a preference toward hydrogen bond–donating molecules for homologous cycHC[6] and cycHC[8]. Guests were characterized by Hirshfeld partial charges on acidic hydrogens and their binding by 1H and 19F NMR titrations. Evaluation of association constants revealed the complexity of the system and indirectly proved an external binding with stoichiometry over 2:1 for both homologs. It was found that overall binding strength is influenced by the stoichiometry of the formed complexes, the partial atomic charge on the hydrogen atom of the hydrogen bond donor, and the bulkiness of the guest. Additionally, a study on the formation of complexes with halogen anions (Cl− and Br−) in methanol and chloroform, analyzed by 1H NMR, did not confirm complexation. The current study widens the scope of potential applications for host molecules by demonstrating the formation of hydrogen-bonded complexes with multisite hydrogen bond acceptors such as cycHC[6] and cycHC[8].

Sensitive Fluorescence and Visual Detection of Organophosphorus Pesticides with Ru(bpy)32+-ZIF-90-MnO2 Sensing Platform

2021 ◽  
Author(s):  
Jun Li ◽  
Yingwei Weng ◽  
Can Shen ◽  
Jiao Luo ◽  
Donghong Yu ◽  
...  
Keyword(s):  
Food Safety ◽  
Fluorescent Probes ◽  
Visual Detection ◽  
Organophosphorus Pesticides ◽  
External Environment ◽  
Global Environment ◽  
Fluorescence Sensing ◽  
Sensing Platform

Fluorescence sensing organophosphorus pesticides (OPs) has been of great importance for both food safety and global environment, however, the reported fluorescent probes are usually directly exposed to the external environment,...

Energy Transfer in a Supramolecular Complex Assembled via Sapphyrin Dimer-mediated Dicarboxylate Anion Chelation

1998 ◽  
Vol 02 (04) ◽  
pp. 315-325 ◽  
Author(s):  
STACY L. SPRINGS ◽  
ANDREI ANDRIEVSKY ◽  
VLADINÍR KRÁL ◽  
JONATHAN L. SESSLER
Keyword(s):  
Energy Transfer ◽  
Fluoride Anion ◽  
Free Base ◽  
Light Harvesting Complex ◽  
Fluorescence Studies ◽  
H Nmr ◽  
Steady State Fluorescence ◽  
Spectroscopic Analyses ◽  
Affinity Constants ◽  
Covalently Linked

The synthesis of a new terephthalate-strapped porphyrin is described. This porphyrin, prepared in the form of the free base and corresponding zinc(II) complex, was designed to act as the photo-donor portion of a novel, non-covalent artificial light-harvesting complex, the other, acceptor component of which is comprised of a covalently linked sapphyrin dimer. UV-vis and 1 H NMR spectroscopic analyses were used to establish that strong complexes are formed between the porphyrin terephthalate and sapphyrin dimer components (affinity constants on the order of 105 M−1 in dichloromethane). In these complexes the dicarboxylate portion of the strapped porphyrin is sandwiched between two sapphyrins of an individual dimer. Steady state fluorescence studies of the resulting ensembles support the conclusion that, upon photoexcitation of the porphyrin subunit, energy transfer from the porphyrin to the sapphyrin dimer occurs efficiently. This intra-ensemble, anion-chelation-based energy transfer can be inhibited by the addition of fluoride anion.

Rhodamine phenol-based fluorescent probe for the visual detection of GB and its simulant DCP

2021 ◽  
Author(s):  
Shouxin Zhang ◽  
Chuan Zhou ◽  
Bo Yang ◽  
Yue Zhao ◽  
Lingyun Wang ◽  
...  
Keyword(s):  
Fluorescent Probe ◽  
Fluorescent Probes ◽  
Visual Detection ◽  
Nerve Agent ◽  
Rapid Response ◽  
Limit Detection

Rhodamine phenol-based fluorescent probes have been synthesized. The probe RBNP demonstrates a rapid response and extreme low limit detection to diethylchlorophosphate and can rapidly and visually detect a real nerve agent GB in vapor.

scholarly journals A multi-functional chemosensor for highly selective ratiometric fluorescent detection of silver(I) ion and dual turn-on fluorescent and colorimetric detection of sulfide

2018 ◽  
Vol 5 (6) ◽  
pp. 180293 ◽  
Author(s):  
Ji Hye Kang ◽  
Ju Byeong Chae ◽  
Cheal Kim
Keyword(s):  
Theoretical Calculations ◽  
Colorimetric Detection ◽  
Fluorescence Emission ◽  
Binding Mode ◽  
Fluorescent Detection ◽  
Mass Spectral ◽  
H Nmr ◽  
Wide Ph Range ◽  
Ph Range ◽  
Nmr Titrations

A multi-functional chemosensor 1 as silver and sulfide detector was synthesized by the combination of octopamine and 4-dimethylaminocinnamaldehyde. Sensor 1 exhibited a ratiometric fluorescence emission for Ag + from blue to sky. The binding mode of 1 and Ag + turned out to be a 1 : 1 ratio as determined using Job plot and electrospray ionization (ESI) mass spectral analyses. The sensing mechanism of 1 with silver ion was unravelled by 1 H NMR titrations and theoretical calculations. Sensor 1 also discerned sulfide by enhancing fluorescence intensity and changing colour from yellow to colourless in aqueous solution. The sensing properties of 1 toward S 2− were investigated by using ESI-mass analysis, Job plot and 1 H NMR titrations. Moreover, 1 could be used as a detector for sulfide in a wide pH range.

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