scholarly journals The influence of certain metal ions on the visible spectra of food dyes

2007 ◽  
Vol 3 (1) ◽  
pp. 1-14 ◽  
Author(s):  
A. V. JONES ◽  
J. D. R. THOMAS
Keyword(s):  
Metal Ions ◽  
Visible Spectra ◽  
Food Dyes

Green Synthesis of Triazole-Based Chemosensors and their Efficacy Towards Mercury Sensing

2020 ◽  
Vol 16 (6) ◽  
pp. 738-743 ◽  
Author(s):  
Poonam Rani ◽  
Kashmiri Lal ◽  
Vikas D. Ghule ◽  
Rahul Shrivastava
Keyword(s):  
Detection Limit ◽  
Metal Ions ◽  
Density Functional ◽  
Organic Molecules ◽  
Functional Theory ◽  
Small Organic Molecules ◽  
Industrial Activities ◽  
Binding Stoichiometry ◽  
Visible Spectra ◽  
Uv Visible

Background: The synthesis of small organic molecules based Hg2+ ions receptors have gained considerable attention because it is one of the most prevalent toxic metals which is continuously discharged into the environment by different natural and industrial activities. 1,4-Disubstituted 1,2,3-triazoles have been reported as good chemosensors for the detection of various metal ions including Hg2+ ions. Methods: The synthesis of 1,2,3-triazoles (4a-4c) was achieved by Cu(I)-catalyzed azide-alkyne cycloaddition, and their binding affinity towards various metal ions and anions were studied by UVVisible titration experiments. The perchlorate salts of metal ions and tetrabutylammonium salts of anions were utilized for the UV-Visible experiments. DFT studies were performed to understand the binding and mechanism on the sensing of 4a toward Hg2+ using the B3LYP/6-311G(d,p) method for 4a and B3LYP/LANL2DZ for 4a-Hg2+ species on the Gaussian 09W program. Results: The UV-visible experiments indicated that the compounds 4a-4c show a selective response towards Hg2+ ion in UV-Visible spectra, while other ions did not display such changes in the absorption spectra. The binding stoichiometry was evaluated by Job’s plot which indicated the 1:1 binding stoichiometry between receptors (4a-4c) and Hg2+ ion. The detection limit of 4a, 4b and 4c for the Hg2+ ions was found to be 29.1 nM, 3.5 μM and 1.34 μM, respectively. Conclusion: Some 1,2,3-triazole derivatives were synthesized (4a-4c) exhibiting high selectively and sensitivity towards Hg2+ ions in preference to other ions. Compound 4a has a low detection limit of 29.1 nM and the binding constant of 2.3×106 M-1. Similarly, 4b and 4c also showed selective sensing towards Hg2+ ions in the μM range. The observed experimental results were corroborated by density functional theory (DFT) calculations.

scholarly journals Novel Mixed Matrix Membranes Based on Polymer of Intrinsic Microporosity PIM-1 Modified with Metal-Organic Frameworks for Removal of Heavy Metal Ions and Food Dyes by Nanofiltration

Membranes ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 14
Author(s):  
Anna Kuzminova ◽  
Mariia Dmitrenko ◽  
Andrey Zolotarev ◽  
Aleksandra Korniak ◽  
Daria Poloneeva ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
High Efficiency ◽  
Metal Organic Frameworks ◽  
Mixed Matrix Membranes ◽  
Polymer Of Intrinsic Microporosity ◽  
Food Dyes ◽  
Metal Organic ◽  
Intrinsic Microporosity

Nowadays, nanofiltration is widely used for water treatment due to its advantages, such as energy-saving, sustainability, high efficiency, and compact equipment. In the present work, novel nanofiltration membranes based on the polymer of intrinsic microporosity PIM-1 modified by metal-organic frameworks (MOFs)—MIL-140A and MIL-125—were developed to increase nanofiltration efficiency for the removal of heavy metal ions and dyes. The structural and physicochemical properties of the developed PIM-1 and PIM-1/MOFs membranes were studied by the spectroscopic technique (FTIR), microscopic methods (SEM and AFM), and contact angle measurement. Transport properties of the developed PIM-1 and PIM-1/MOFs membranes were evaluated in the nanofiltration of the model and real mixtures containing food dyes and heavy metal ions. It was found that the introduction of MOFs (MIL-140A and MIL-125) led to an increase in membrane permeability. It was demonstrated that the membranes could be used to remove and concentrate the food dyes and heavy metal ions from model and real mixtures.

Experimental and Theoretical Study on Transition Metal Ion Doped TiO2

2011 ◽  
Vol 233-235 ◽  
pp. 2219-2222 ◽  
Author(s):  
Xue Chun Zhong ◽  
Zhan Chang Pan ◽  
Zhi Gang Wei ◽  
Shu Guang Xie ◽  
Zhen Jun Cheng ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Metal Ion ◽  
Anatase Phase ◽  
Sol Gel ◽  
Transition Metal Ions ◽  
Transition Metal Ion ◽  
Visible Light Range ◽  
Visible Spectra ◽  
Uv Visible

In this paper, TiO2crystallines doped with transition metal ions have been prepared by sol-gel method. The UV-visible spectra indicated that the doping with transition metal ions (especially Cu2+, Mn2+and Cr3+ions) could effectively improve the absorption of TiO2crystals in the visible-light range. The XRD results showed that the doping does not affect the anatase phase of TiO2. The band structure and the UV-vis absorption spectrum of Mn2+ions doped-TiO2were also calculated by DFT (density function theory) method, which indicated that the doping with transition metal ion could make the band gap of TiO2smaller and a red shift in optical absorption.

scholarly journals COORDINATIVE INTERACTION OF CHITOSAN-AZO DYES TOWARDS SELECTED FIRST ROW TRANSITION METALS

2019 ◽  
Vol 17 (1) ◽  
pp. 1-8
Author(s):  
O. EJEROMEDOGHENE ◽  
M. D. ADEOYE ◽  
S. ADEWUYI ◽  
S. ADEWUYI
Keyword(s):  
Transition Metals ◽  
Metal Ions ◽  
Attractive Alternative ◽  
Vis Spectroscopy ◽  
Visible Spectra ◽  
Sudan Iii ◽  
Ft Ir ◽  
Uv Visible ◽  
High Yields ◽  
Chitosan Composite

Chitosan is an abundant bio-polymer obtained by alkaline deacetylation of chitin in the exoskeleton of crustaceans. Chitosan was found to be an attractive alternative to other bio materials due to its significant physicochemical behavior and ability to selectively bind to transition and post transition metals. In order to improve the performance of this bio-polymer, chemical modification of chitosan composite and its derivatives have gained much attention. In this study, a new biopolymeric ligand was synthesized by functionalizing chitosan with eriochrome black T (EBT) and sudan III (S3) dyes. The functionalized compounds were interacted with Co(II), Ni(II), Cu(II) and Zn(II) metal ions at varied concentrations leading to complex formation. Both the new ligand and the complexes obtained at high yields were characterized using Fourier Transform Infrared (FT-IR) and Uv-Vis Spectroscopy. The FT-IR spectra revealed a possible hydrogen bonding between chitosan and the azo dye. It also suggests an interaction between the N=N of the ligand with the metal ions. In addition, the Uv-Visible spectra studies showed that on reacting various concentrations of metal ions with ligand the absorbance increases with decreasing concentration of the metal ions and was able to interact with as low as 0.001 M of the studied metal salts.  

Electrochemistry and spectroelectrochemistry of β-pyrazino-fused tetraarylporphyrins in nonaqueous media

2015 ◽  
Vol 19 (01-03) ◽  
pp. 388-397 ◽  
Author(s):  
Yuanyuan Fang ◽  
Federica Mandoj ◽  
Lihan Zeng ◽  
Rajesh Pudi ◽  
Manuela Stefanelli ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Thin Layer ◽  
Metal Ions ◽  
Supporting Electrolyte ◽  
Cation Radical ◽  
Central Metal ◽  
Redox Potentials ◽  
Nonaqueous Media ◽  
Visible Spectra ◽  
Uv Visible

Bis-porphyrins containing a β,β′-fused pyrazino (Pz) linking group were examined by electrochemistry and thin-layer UV-visible spectroelectrochemistry in PhCN containing 0.1 M tetra-n-butylammonium perchlorate (TBAP) as supporting electrolyte. The investigated compounds are represented as M(TPP)-Pz-(TPP)M, where TPP is the dianion of tetraphenylporphyrin and M = Zn(II) , Cu(II) or Ag(II) . The effect of the linking Pz group on the redox potentials and UV-visible spectra of the neutral, electroreduced and electrooxidized bis-porphyrins is discussed and the data compared to what is observed for related monoporphyrins and earlier characterized bis-porphyrins containing a tetraazaanthracene (TA) linking group and the same central metal ions. The Cu(II) and Zn(II) Pz linked bis-porphyrins exhibit a relatively strong interaction between the two equivalent porphyrin macrocycles as evidenced by UV-visible spectra of the neutral compounds and characteristic splitting of redox processes for three of the four electron transfer reactions, the one exception being the first oxidation, where no splitting of potentials is observed in the formation of the bisporphyrin bis-cation radical, [M(TPP)-Pz-(TPP)M]2+. The first oxidation and first reduction of the bis-porphyrin with two Ag(II) central metal ions occurs via two overlapping one-electron transfer steps in each process indicating equivalent, but non-interacting redox centers. This difference in redox behavior is due to differences in the site of electron transfer, metal centered for the Ag(II) bisporphyrins, which undergo Ag(II) / Ag(III) and Ag(II) / Ag(I) processes as compared to only ring centered electron transfers for the Cu(II) and Zn(II) derivatives. The Pz-linked Zn(II) bis-porphyrins have a larger average HOMO–LUMO gap (2.01 V) as compared to related tetraazaanthracene linked bis-porphyrins (1.67 V), which were earlier characterized in the literature, but the gap is smaller than that for the mono-porphyrins with the same central metal ions (2.17 V). Each redox reaction of the investigated bisporphyrins was characterized by thin-layer spectroelectrochemistry.

scholarly journals Study of interaction of metal ions with methylthymol blue by chemometrics and quantum chemical calculations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zolaikha Rasouli ◽  
Mehdi Irani ◽  
Sonia Jafari ◽  
Raouf Ghavami
Keyword(s):  
Charge Transfer ◽  
Metal Ions ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Multivariate Curve Resolution ◽  
Molar Ratio ◽  
Ligand Charge Transfer ◽  
Visible Spectra ◽  
Uv Visible ◽  
Methylthymol Blue

AbstractIn this study, we determine the acidity constants of methylthymol blue (MTB) and association constants of its complexes with the ZnII, CuII, and FeII metal ions (MIs), through theoretical and experimental means. The complexes were characterized using UV–Visible absorption spectroscopy combined with soft/hard chemometrics methods and quantum chemical calculations. Quantum chemical calculations revealed that electronic transitions in the UV–Visible spectra of MTB have mixed n → π* and π → π* characters. The results of molar ratio and multivariate curve resolution alternating least squares (MCR-ALS) revealed the formation of successive 1:2 and 1:1 complexes (MI:MTB) for the ZnII and CuII systems. However, the formation of successive 1:1 and 2:1 complexes are suggested for FeII by the molar ratio and MCR-ALS. The majority of transitions observed in the UV–Visible spectra of the Zn(MTB) and Cu(MTB) complexes have ligand-to-ligand charge transfer (LLCT) characters. However, the transitions in the UV–Visible spectrum of the Fe(MTB) complex have LLCT and metal-to-ligand charge transfer (MLCT) characters. For the Fe2(MTB) complex, the lowest energy transition of has an LLCT character. However, its higher energy transitions are a mixture of LLCT, MLCT, and metal-to-metal charge transfer (MMCT) characters. The correlation between experimental and computed wavelengths revealed that the 1:1 complexes of ZnII and CuII prefer square pyramidal geometries. However, the FeII complexes always show octahedral geometry.

Dyeing of Mulberry Silk Using Natural Safflower Yellow Pigment

2014 ◽  
Vol 670-671 ◽  
pp. 197-200
Author(s):  
Yan Mei Jia ◽  
Hong Wu Jiang
Keyword(s):  
Metal Ions ◽  
Ph Value ◽  
Yellow Pigment ◽  
Ph Change ◽  
Spectra Analysis ◽  
Visible Spectra ◽  
Color Yield ◽  
Silk Fabrics ◽  
Silk Dyeing ◽  
The Stability

A natural yellow pigment is extracted from carthamus tinctorious and the stability of the pigment on metal ions and the pH change are studied by visible spectra analysis. The extracts are applied to dye silk fabric and the dyeing properties are tested. Results show that the maximum absorption wavelength of the extract changed with pH value and metal ions. The safflower yellow pigment has good property for silk dyeing, the mordant dyed silk fabrics can obtain a deeper color yield and a better washing and rubbing color fastness.

scholarly journals Synthesis and Spectral Studies of Co(II),Ni(II),Zn(II) and Cd(II) Complexes with Ligand 2-[4- Carboxy methyl phenyl azo] -4,5-diphenyl imidazole (4CMeI)

2013 ◽  
Vol 10 (2) ◽  
pp. 420-431
Author(s):  
Baghdad Science Journal
Keyword(s):  
Metal Ions ◽  
Spectroscopic Studies ◽  
Ratio Method ◽  
Spectral Studies ◽  
Geometrical Structures ◽  
Visible Spectra ◽  
Mole Ratio Method ◽  
Complex Solutions ◽  
Carboxy Methyl ◽  
Methyl Phenyl

A new chelate complexes of Co(II),Ni(II),Zn(II) and Cd(II) were prepared by reacting these ions with the ligand 2-[4- Carboxy methyl phenyl azo]-4,5-diphenyl imidazole (4CMeI) The preparation were conducted after fixing the optimum conditions such as (pH) and concentration .UV- visible spectra of these complex solutions were studied for a range of (pH) and concentration which obey lampert-Beers Law.The structures of complexes were deduced according to mole ratio method which were obtained from the spectroscopic studies of the complex solutions .The ratios of metal: ligand obtained were (1:2) for all complexes..(UV-Vis) absorption spectra and The infrared spectra of the chelating complexes were studied ,this may indicate that coordination between the metal ions and our ligand takes place.The conductivity measurements , elemental analysis ,the percentage of some metal ions and the measurements of magnetic susceptibility of the complexes were determined ,Depending on these results , in addition to, We may conclude that the ligand was bidentate Also the proposed geometrical structures of the complexes of Co(II), Ni(II), Zn(II) and Cd (II) ions are octahedral

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