scholarly journals A DFT Investigation of Tris-(4´-(Amino)(1,1´-biphenyl)-3,4-diol) Fe(III) Complex

2018 ◽  
Vol 66 (1) ◽  
pp. 67-71
Author(s):  
Mohammad A Matin ◽  
Mohammed A Aziz ◽  
M Saiful Islam
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Metal Ion ◽  
Density Functional ◽  
Structural Parameters ◽  
Chelating Agent ◽  
Transition Metal Ions ◽  
Binding Energies ◽  
Molecular Properties ◽  
Electronic Band

Phenolic compounds, known as the pyrocatechol act as a metal chelating agent. Molecular details of cross-linking of pyrocatechol by transition metal ions are largely unknown. In the present study, the molecular properties of the tris-(4´-(amino)(1,1´-biphenyl)-3,4-diol)- Fe(III) complex have been investigated using density functional theory (DFT) at 6-311G(d,p). Calculated molecular properties of the optimized structure, the binding energies and spectroscopic properties are compared with the available experimental results. For the tris-complex investigated, the binding of Fe (III) with the catechol derivative is not as strong as the binding of other metal ions with catechol. The IR stretching bands show that the strong IR intensities is due to large charge polarization. Calculated electronic band gap is 2.45 eV which is in the range of transition metal ion-tris-(4´-(amino)(1,1´-biphenyl)-3,4-diol) complexes. The metal-ligand binding energy is 513.54 kcal mol-1, which could be used in understanding the speciation of Fe(III)-catechol complex. Structural parameters obtained from the DFT calculations are in good agreement with the crystallographic data. Dhaka Univ. J. Sci. 66(1): 67-71, 2018 (January)

scholarly journals Pt(dithiolene)-Based Colorimetric Chemosensors for Multiple Metal-Ion Sensing

2021 ◽  
Vol 13 (15) ◽  
pp. 8160
Author(s):  
Heawon Son ◽  
Seohyeon Jang ◽  
Gayoung Lim ◽  
Taeyong Kim ◽  
Inho Nam ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Metal Ion ◽  
Density Functional ◽  
Low Cost ◽  
Density Functional Theory Calculations ◽  
Transition Metal Ions ◽  
Field Analysis ◽  
Ion Sensing ◽  
Metal Ion Sensing

Colorimetric chemosensors are widely employed for in-field analysis to detect transition metal ions in real-time with the naked eye. Colorimetric chemosensors have attracted considerable attention because they can conveniently provide quantitative and qualitative information at a low cost. However, the development of colorimetric chemosensors for multiple-ion sensing where metal cations coexist has been limited. For this reason, we developed a new type of transition metal ion sensing material by selectively replacing functional groups on (diphosphine)Pt(dmit) molecules. The terminal groups of the diphosphine ligand were successfully substituted by the cyclohexyl groups, increasing the electron density of the thione moiety. Due to the electron donation ability of the cyclohexyl terminal groups, the proposed chemosensing material was able to selectively detect the mixture of Hg2+, Cu2+, and Ag+ in the presence of many types of interfering cations. To gain insight into the binding mechanisms between the metal ions and the developed (dchpe)Pt(dmit) molecule, density functional theory calculations were also performed.

scholarly journals Characterization of Chromium-tris(catecholate) Complex: A Theoretical Study

2017 ◽  
Vol 65 (2) ◽  
pp. 113-117
Author(s):  
Mohammad A Matin ◽  
Mazharul M Islam ◽  
Mohammed A Aziz
Keyword(s):  
Binding Energy ◽  
Transition Metal ◽  
Metal Ions ◽  
Metal Ion ◽  
Hybrid Approach ◽  
Transition Metal Ions ◽  
Electronic Band ◽  
Catecholate Complex ◽  
Electronic Band Gap

Phenolic compounds generally have special smell and are easily soluble in water, organic solvents (alcohols, esters, chloroform, ethyl acetate) and in alkali. Phenols produce coloured complexes with heavy metal ions, such as with chromium ion. The molecular details underlying the cross-linking mediated by transition metal ions are largely unknown. Using HF/DFT hybrid approach B3LYP, this study examines the structure, binding energy, spectroscopic and electronic properties of complex formed by the attachment of Cr3+ with a catechol ligand. Our study shows that the binding of Cr3+ with the catechol ligand is not as strong as the binding of other metal ions with catechol.The calculated FTIR spectra show strong IR intensities due to large charge polarization. The UV-Vis absorption spectrum of the tris-catecholato-Cr3+complex shows a clear ligand-to-metal charge transfer. The calculated electronic band gap is 4.06 eV which is in the range of transition metal ion tris-catechol complexes. Thermodynamic properties studied in this work show that the metal ion-ligand binding energy (532.99 kcal/mol) is close to those of the hexa-aqua complexes (ranging from 540 to 553 kcal/mol). Dhaka Univ. J. Sci. 65(2): 113-117, 2017 (July)

2,2î-Bipyridine Catalyzed Bleaching of Cotton Fibers with Peracetic Acid

1988 ◽  
Vol 58 (4) ◽  
pp. 198-210 ◽  
Author(s):  
James W. Rucker ◽  
David M. Cates
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Peracetic Acid ◽  
Metal Ion ◽  
Solution Treatment ◽  
Transition Metal Ions ◽  
Ferrous Ion ◽  
Cotton Fibers ◽  
Lauryl Sulfate ◽  
Ferrous Ions

Peracetic acid can be catalyzed to bleach cotton fibers at temperatures as low as 30°C by incorporating 2,2î-bipyridine in the bleach solution. Treatment of the fibers with HCl prior to bleaching reduces bleaching effectiveness by removing trace transition metal ions from the fibers. Sorption of individual ions (Cr+3 Mn+2, Fe+2, Fe+3 Co+2, Ni+2, Cu+2, and Zn+2) by HCl treated cotton fibers prior to bleaching indicates that the ferrous ion produces the greatest catalytic effect, and it is only effective when the metal ion is in the fiber as opposed to in solution. Ferrous ions in the fibers sorb 2,2î-bipyridine from solution to form the tris-2,2î-bipyridine ferrous ion complex that is associated with the fibers, and it is the trischelate associated with the fibers that catalyzes bleaching. The effects of pH, temperature, and concentrations of 2,2î-bipyridine, sodium lauryl sulfate, and transition metal ions (in the fibers and in solution) on bleaching effectiveness and peracetic acid decomposition have been studied, and a bleaching mechanism is proposed.

Intermediate-stage transition metal ion exchange in a zeolite X

1982 ◽  
Vol 35 (7) ◽  
pp. 1335 ◽  
Author(s):  
M Chatterjee ◽  
D Ganguli
Keyword(s):  
Ion Exchange ◽  
Transition Metal ◽  
Metal Ions ◽  
Metal Ion ◽  
Intermediate Stage ◽  
Transition Metal Ions ◽  
Zeolite X ◽  
Counter Ions ◽  
Metal Ion Exchange ◽  
Exchange Behaviour

The exchange behaviour of some divalent transition metal ions M2+ (Zn2+, Cu2+, Ni2+, Co2+, Mn2+) in a zeolite NaX (SiO2/Al2O3 2.75) was studied at intermediate stages before equilibrium. The equivalent counter ion supply in the solution, given by the equivalent ratio of the two counter ions 2M2+/Na+, was found to be critical in determining the saturation level of exchange. The series of relative abilities of exchange was very similar to the well known selectivity series at equilibrium. It is suggested that water exchange of the metal ions in solution could be one of the factors controlling the relative ease of ion exchange.

scholarly journals Adsorption of Divalent Transition Metal Ions with a Chelating Agent on Octadecyl Silica Gel

2004 ◽  
Vol 20 (10) ◽  
pp. 1463-1464 ◽  
Author(s):  
Masamitsu IIYAMA ◽  
Syunichi OSHIMA ◽  
Hisao KOKUSEN ◽  
Masami SEKITA ◽  
Shigekazu TSURUBOU ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Silica Gel ◽  
Chelating Agent ◽  
Transition Metal Ions ◽  
Octadecyl Silica ◽  
Octadecyl Silica Gel

Layered Tungsten Oxide-Based Hybrid Materials Incorporating Transition Metal Ions

2004 ◽  
Vol 847 ◽  
Author(s):  
Bridget Ingham ◽  
S. V. Chong ◽  
Jeff L. Tallon
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Tungsten Oxide ◽  
Hybrid Materials ◽  
Transition Metal Oxides ◽  
Metal Ion ◽  
Interlayer Spacing ◽  
Transition Metal Ions ◽  
Ferromagnetic Transition ◽  
Inorganic Framework

ABSTRACTLayered organic-inorganic hybrid materials based on tungsten oxide as the inorganic framework have been synthesised to include transition metal ions. The resulting materials have been characterised using a number of techniques. X-ray diffraction shows an interlayer expansion with increasing alkyl length. Infrared vibrational spectra of manganese tungstate compounds indicate the organic amine molecules are neutrally charged, and the inorganic framework is unaltered as one varies the organic intercalate. The magnetic behaviour of the materials has also been explored using a SQUID magnetometer. In the manganese tungstate hybrids an antiferromagnetic (AF) transition is observed, which decreases in temperature as the inorganic interlayer spacing is increased. A nickel tungstate hybrid sample, on the other hand, displays a ferromagnetic transition, which we attribute to a canted AF phase below 15 K. In all cases studied, the behaviour can be mapped to an effective moment (Peff) per transition metal ion, which agrees well with theoretical and literature values for other transition metal oxides.

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