scholarly journals Amphiphilic Fluorescent Well-Defined Living Polymer from Indole-3-Carboxaldehyde and 4-Bromo-1, 8-Naphthalic Anhydride: Synthesis and Characterization

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Ambika Srivastava ◽  
Pooja Singh ◽  
Arti Srivastava ◽  
Rajesh Kumar
Keyword(s):  
Aqueous Solution ◽  
Fluorescence Emission ◽  
Green Fluorescence ◽  
Blue Fluorescence ◽  
Naphthalic Anhydride ◽  
H Nmr ◽  
Uv Visible ◽  
Polymer Bearing ◽  
Absorption And Emission Spectroscopy ◽  
Good Agreement

We reported a well-defined amphiphilic fluorescent polymer bearing indole repeating units with naphthalimide pendants obtained by ATRP followed by chemical modification. The obtained polymer poly (N-allyl indole-2-(4-hydroxybutyl)-1, 8-naphthalimide) (PAIHN) was characterized by 1H NMR, FTIR, and GPC. The polymer showed a specific fluorescence emission maximum at 538 nm excited at 435 nm in aqueous solution. The amphiphilic nature of the polymer was investigated in aqueous solution using two spectroscopic methods, namely, absorption and emission spectroscopy. The Critical Miceller Concentration values obtained by UV-visible and fluorescence are in good agreement with each other. The micelles were characterized by TEM at concentration of 0.014 mg/mL. The polymer PAIHN prepared after tweaking exhibits green fluorescence at 538 nm due to the significant effect of naphthalimide moieties, whereas before tweaking the polymer poly (1-allyl indole-3-carbaldehyde) (PAIC) exhibits blue fluorescence at 425 nm due to indole repeating units of the polymer.

scholarly journals A pseudorotaxane formed from a cucurbit[7]uril wheel and a bioinspired molecular axle with pH, light and redox-responsive properties

2020 ◽  
Vol 92 (2) ◽  
pp. 301-313 ◽  
Author(s):  
André Seco ◽  
Ana Marta Diniz ◽  
João Sarrato ◽  
Henrique Mourão ◽  
Hugo Cruz ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Electrochemical Techniques ◽  
Fluorescence Emission ◽  
Hydration Reaction ◽  
Binary Complex ◽  
Acidic Media ◽  
H Nmr ◽  
Redox Responsive ◽  
Neutral Conditions ◽  
Reversible Hydration

AbstractA pH-, light- and redox-responsive flavylium-bipyridinium molecular dyad (bioinspired in natural anthocyanins) was synthesized and employed to devise a pseudorotaxane with the macrocycle cucurbit[7]uril (CB7) in aqueous solution. The inclusion complex was characterized by UV-Vis absorption, fluorescence emission, NMR and electrochemical techniques which demonstrate formation of a stable binary complex between the dyad and CB7 both under acidic and neutral conditions. It is noteworthy that the flavylium-bipyridinium tricationic dyad is only stable in highly acidic media, undergoing a reversible hydration reaction at slightly acidic or neutral pH to give a trans-chalcone-bipyridinium dication. 1H NMR experiments showed that in this last species the CB7 binds to the bipyridinium unit while in the tricationic species the macrocycle is positioned between the flavylium and the bipyridinium moieties. The different location of the CB7 wheel in the two dyad states allows control of the shuttling movement using light and pH stimuli that trigger the interconversion between these two species.

scholarly journals Supramolecular Encapsulation of Vitamin B6by Macrocyclic Nanocontainer Cucurbit[7]uril

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Wanying Li ◽  
Shengke Li ◽  
Ian W. Wyman ◽  
Donal H. Macartney ◽  
Qingwen Zhang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Molecular Modeling ◽  
Vitamin B ◽  
Pyridoxine Hydrochloride ◽  
Biologically Relevant ◽  
H Nmr ◽  
Molecular Container ◽  
Uv Visible ◽  
The Stability ◽  
First Time

A pharmaceutically and biologically relevant molecule, pyridoxine hydrochloride (vitamin B6), was encapsulated inside the cavity of a molecular container, cucurbit[7]uril (CB[7]), in aqueous solution. The CB[7] based “nanocapsule” of vitamin B6has been investigated for the first time, via1H NMR and UV-visible spectroscopic titrations (including Job’s plot) andab initiomolecular modeling. The results have demonstrated that vitamin B6forms stable host-guest complexes within CB[7] in 1 : 1 stoichiometry, with a binding affinity of(4.0±0.5)×103 M−1. Such a nanocapsule could potentially find application in vitamin B6formulation for the purpose of enhancing the stability, absorption, and delivery of this important vitamin.

Enhanced-Fluorescence of a Dye on DNA- assembled Gold Nano-Dimers Discriminated by Lifetime Correlation Spectroscopy

2017 ◽  
Author(s):  
Pedro M. R. Paulo ◽  
David Botequim ◽  
Agnieszka Jóskowiak ◽  
Sofia Martins ◽  
Duarte M. F. Prazeres ◽  
...  
Keyword(s):  
Single Molecule ◽  
Fluorescence Emission ◽  
Directed Assembly ◽  
Plasmon Mode ◽  
Correlation Spectroscopy ◽  
Enhanced Fluorescence ◽  
Detection Volume ◽  
Relaxation Component ◽  
Good Agreement ◽  
Confocal Detection

<div> <div> <div> <p>We have employed DNA-directed assembly to prepare dimers of gold nanoparticles and used their longitudinally coupled plasmon mode to enhance the fluorescence emission of an organic red-emitting dye, Atto-655. The plasmon- enhanced fluorescence of this dye using dimers of 80 nm particles was measured at single molecule detection level. The top enhancement factors were above 1000-fold in 71% of the dimers within a total of 32 dimers measured, and, in some cases, they reached almost 4000-fold, in good agreement with model simulations. Additionally, fluorescence lifetime correlation analysis enabled the separation of enhanced from non-enhanced emission simultaneously collected in our confocal detection volume. This approach allowed us to recover a short relaxation component exclusive to enhanced emission that is attributed to the interaction of the dye with DNA in the interparticle gaps. </p> </div> </div> </div>

Enantioselective Recognition of Chiral Guests by the Water-Soluble Chiral Keplerate {Mo132} Spherical Capsule with 30 Inner Lactate Ligands

2019 ◽  
Author(s):  
Nancy Watfa ◽  
Weimin Xuan ◽  
Zoe Sinclair ◽  
Robert Pow ◽  
Yousef Abul-Haija ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Chiral Recognition ◽  
Association Constants ◽  
Water Soluble ◽  
Enantioselective Recognition ◽  
H Nmr ◽  
Dosy Nmr ◽  
Spherical Capsule ◽  
Surface Pores ◽  
Guest Chemistry

Investigations of chiral host guest chemistry are important to explore recognition in confined environments. Here, by synthesizing water-soluble chiral porous nanocapsule based on the inorganic metal-oxo Keplerate-type cluster, {Mo<sub>132</sub>} with chiral lactate ligands with the composition [Mo<sub>132</sub>O<sub>372</sub>(H<sub>2</sub>O)<sub>72</sub>(<i>x-</i>Lactate)<sub>30</sub>]<sup>42-</sup> (<i>x</i> = D or L), it was possible to study the interaction with a chiral guest, L/D-carnitine and (<i>R</i>/<i>S</i>)-2-butanol in aqueous solution. The enantioselective recognition was studied by quantitative <sup>1</sup>H NMR and <sup>1</sup>H DOSY NMR which highlighted that the chiral recognition is regulated by two distinct sites. Differences in the association constants (K) of L- and D-carnitine, which, due to their charge, are generally restricted from entering the interior of the host, are observed, indicating that their recognition predominantly occurs at the surface pores of the structure. Conversely, a larger difference in association constants (K<i><sub>S</sub></i>/K<i><sub>R</sub></i> = 3) is observed for recognition within the capsule interior of (<i>R</i>)- and (<i>S</i>)-2-butanol.

scholarly journals A Novel Thiosemicarbazide-Based Fluorescent Chemosensor for Hypochlorite in Near-Perfect Aqueous Solution and Zebrafish

Chemosensors ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 65
Author(s):  
Minji Lee ◽  
Donghwan Choe ◽  
Soyoung Park ◽  
Hyeongjin Kim ◽  
Soomin Jeong ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Reactive Oxygen Species ◽  
Aqueous Solution ◽  
Fluorescence Quenching ◽  
Limit Of Detection ◽  
Fluorescent Sensor ◽  
Ionization Mass ◽  
Oxygen Species ◽  
Marked Selectivity ◽  
Uv Visible

A novel thiosemicarbazide-based fluorescent sensor (AFC) was developed. It was successfully applied to detect hypochlorite (ClO−) with fluorescence quenching in bis-tris buffer. The limit of detection of AFC for ClO− was analyzed to be 58.7 μM. Importantly, AFC could be employed as an efficient and practical fluorescent sensor for ClO− in water sample and zebrafish. Moreover, AFC showed a marked selectivity to ClO− over varied competitive analytes with reactive oxygen species. The detection process of AFC to ClO− was illustrated by UV–visible and fluorescent spectroscopy and electrospray ionization–mass spectrometry (ESI–MS).

scholarly journals Unusual piezochromic fluorescence of a distyrylpyrazine derivative crystals: phase transition through [2 + 2] photocycloaddition under UV irradiation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Young-Jae Jin ◽  
Hyosang Park ◽  
Byung-Chun Moon ◽  
Jae Hong Kim ◽  
Wang-Eun Lee ◽  
...  
Keyword(s):  
Phase Transition ◽  
Solid State ◽  
Uv Irradiation ◽  
Mechanical Grinding ◽  
Green Color ◽  
H Nmr ◽  
Uv Visible ◽  
Stacking Structure ◽  
Orange Color ◽  
Molecular Stacking

AbstractThe piezochromic fluorescence (FL) of a distyrylpyrazine derivative, 2,3-diisocyano-5,6-distyrylpyrazine (DSP), was investigated in this study. Depending on the recrystallization method, DSP afforded two different crystals with green and orange FL emission. The orange color FL emission crystal (O-form) was easily converted to the green color FL emission one (G-form) by manual grinding. The G-form was also converted to a slightly different orange color FL emission crystal (RO-form) by a weak UV irradiation. When the RO-form was ground again, the G-form was regenerated. The FL colors changed between the G- and RO-forms over several ten times by repeated mechanical grinding and UV irradiation. The FL, UV–visible, 1H-NMR and XRD results showed that the O (or RO)-to-G transformation induced by mechanical stress results from the change of degree of molecular stacking from dense molecular stacking structure to relatively loose molecular stacking structure, whereas the G-to-RO reconversion by UV irradiation results from return to dense molecular stacking structure again due to lattice movement (lattice slipping) allowed by photocycloaddition in solid-state.

scholarly journals Evaluation of N-Alkyl-bis-o-aminobenzamide Receptors for the Determination and Separation of Metal Ions by Fluorescence, UV-Visible Spectrometry and Zeta Potential

Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1737 ◽  
Author(s):  
Marisela Martinez-Quiroz ◽  
Xiomara E. Aguilar-Martinez ◽  
Mercedes T. Oropeza-Guzman ◽  
Ricardo Valdez ◽  
Eduardo A. Lopez-Maldonado
Keyword(s):  
Aqueous Solution ◽  
Zeta Potential ◽  
Metal Ions ◽  
Environmental Concern ◽  
Separation Of Metal Ions ◽  
Complexing Capacity ◽  
Alkyl Groups ◽  
Molecular Fluorescence ◽  
Uv Visible ◽  
Phase Sensor

This paper presents the synthesis and evaluation of physicochemical behavior of a new series of N-alkyl-bis-o-aminobenzamides (BOABs) in aqueous solution. The study was targeted to the complexing capacity of five metal ions (Fe2+, Cu2+, Cd2+, Hg2+ and Pb2+) of environmental concern as the medullar principle of a liquid phase sensor for its application in the determination of these metal ions due to its versatility of use. Molecular fluorescence, UV-visible and Zeta potential were measured for five BOABs and the effect of alkyl groups with different central chain length (n = 3, 4, 6, 8 and 10) on physicochemical performance determined. The results have shown that these derivatives present higher sensibility and selectivity for Cu2+ even in the presence of the other metal ions. An additional application test was done adding a pectin (0.1 wt %) solution to the BOAB-Cu+2 complex to obtain a precipitate (flocs) as a potential selective separation process of Cu from aqueous solution. The solid was then lyophilized and analyzed by SEM-EDS, the images showed spheric forms containing Cu+2 with diameter of approximately of 8 μm and 30 wt %.

scholarly journals Water-soluble β-aminobisulfonate building blocks for pH and Cu2+ indicators

RSC Advances ◽  
2016 ◽  
Vol 6 (88) ◽  
pp. 84712-84721 ◽  
Author(s):  
Maria A. Cardona ◽  
Marina Kveder ◽  
Ulrich Baisch ◽  
Michael R. Probert ◽  
David C. Magri
Keyword(s):  
Nmr Spectroscopy ◽  
Building Blocks ◽  
Water Soluble ◽  
Visible Absorption ◽  
H Nmr ◽  
Uv Visible

Two phenyl β-aminobisulfonate ligands characterised by UV-visible absorption, EPR and 1H NMR spectroscopy exhibit evidence for binding with Cu2+ in water and methanol.

Synthesis and properties of a sterically encumbered poly(thienylene vinylene): poly[E-1,2-(4,4prime-dihexyl-2,2prime-dithienyl)ethylene]

1998 ◽  
Vol 76 (11) ◽  
pp. 1524-1529
Author(s):  
Jimmy Lowe ◽  
Carl Bartels ◽  
Steven Holdcroft
Keyword(s):  
Ftir Spectroscopy ◽  
Electrically Conducting ◽  
H Nmr ◽  
Visible Photoluminescence ◽  
Micron Size ◽  
Visible Irradiation ◽  
Uv Visible ◽  
The Stability ◽  
Doped Polymer ◽  
Polythiophene Derivative

Electrically conducting poly[E-1,2-(4,4prime-dihexyl-2,2prime-dithienyl)ethylene] was synthesized and structurally characterized by UV-visible, 1H NMR, and FTIR spectroscopy. The head-to-head arrangement of the alkylthiophene dyads directly affects the UV-visible, photoluminescence, and electroluminescence maxima of the polymer. The conductivity of the doped polymer was measured to be ~2 S cm-1 and the stability of the oxidized polymer possessing various dopants was compared. UV-visible irradiation of PDHDTE rendered the films insoluble and photolithography was used to produce micron-size images. FTIR was used to monitor the photoproducts during photolysis of PDHDTE. Mechanisms of photooxidation were proposed, based on the photoproducts observed.Key words: polythiophene derivative, head-to-head dyad, photolithography, photooxidation, electroluminescence.

Sign in / Sign up

Export Citation Format

Share Document