scholarly journals Selective Chromogenic Recognition of Copper(II) Ion by Thiacalix[4]arene Tetrasulfonate and Mechanism

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 612 ◽  
Author(s):  
Shufang Zhu ◽  
Lilin Lu
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Density Functional ◽  
Color Change ◽  
Bathochromic Shift ◽  
Transition Metal Ions ◽  
Water Soluble ◽  
Ion Concentration ◽  
Absorption Bands ◽  
Simple Method

Detection of biologically important transition metal ions such as copper by using a simple method is desirable and of great importance. In this work, we firstly reported that water-soluble thiacalix[4]arene tetrasulfonate (TCAS) exhibited selective chromogenic recognition towards copper(II) ion over other transition metal ions. Color change from colorless to salmon pink was observed in TCAS solution, weak bathochromic shift was induced in UV absorption spectrum of TCAS upon addition of copper(II) ion, and the absorbance of characteristic absorption band at 312 nm increased linearly with copper(II) ion concentration. The recognition mechanism of TCAS to copper(II) ion was investigated by a comparative study with calix[4]arene tetrasulfonate (CAS) and time-dependent density functional theory(TD-DFT) study, and the absorption bands were assigned based on transition orbital analysis.

Calculation of crystal field splittings in distorted coordination polyhedra: spectra and thermodynamic properties of minerals

1972 ◽  
Vol 38 (300) ◽  
pp. 909-917 ◽  
Author(s):  
Bernard J. Wood ◽  
R. G. J. Strens
Keyword(s):  
Charge Transfer ◽  
Transition Metal ◽  
Metal Ions ◽  
Crystal Field ◽  
Transition Metal Ions ◽  
Orbital Energy ◽  
Absorption Bands ◽  
Simple Method ◽  
Coordination Polyhedra ◽  
Metal Metal

SummaryA simple method has been developed for calculating the d-orbital energy levels of transition-metal ions in coordination polyhedra with both orthogonal and non-orthogonal distortions, using equations based on those derived by Ballhausen (1954). The input data are atomic coordinates, a standard value of the crystal field splitting parameter Δ at known metal-ligand distance, and the ratio of radial integrals B2/B4, which is approximately constant for a given ion. The method can be applied to polyhedra containing different ligands.Application of the equations to the Mn3+ (M3) site in piemontite and the Fe2+ (M2) site in orthopyroxene gives calculated transition energies in good agreement with the observed band energies.The calculations permit definite assignment of the great majority of d-d absorption bands even in multi-site phases, and enable discrimination of crystal-field and charge-transfer bands in mineral spectra. They also throw light on the fine structures of both oxygen → metal and metal → metal charge-transfer bands, and allow the calculation of crystal-field stabilization enthalpy and electronic entropy. The latter is a previously neglected energy term that contributes significantly to the energetics of reactions within and between phases containing transition-metal ions.

Behavior of Polyelectrolyte Gels in Concentrated Solutions of Highly Soluble Salts

MRS Advances ◽  
2020 ◽  
Vol 5 (17) ◽  
pp. 907-915 ◽  
Author(s):  
Jessica L. Sargent ◽  
Xunkai Chen ◽  
Mitchell C. Brezina ◽  
Sebastian Aldwin ◽  
John A. Howarter ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
High Performance Concrete ◽  
Group Versus ◽  
Transition Metal Ions ◽  
Main Group ◽  
Ion Concentration ◽  
Polyelectrolyte Gels ◽  
Counter Ion ◽  
Versus Transition

ABSTRACTIonic hydrogels are an abundant class of materials with applications ranging from drug delivery devices to high performance concrete to baby diapers. A more thorough understanding of interactions between polyelectrolyte networks and ionic solutes is critical as these materials are further tailored for performance applications in highly targeted ionic environments. In this work, we seek to develop structure-property relationships between polyelectrolyte gels and environments containing high concentrations of multivalent ions. Specifically, this work seeks to elucidate the causes behind differences in hydrogel response to divalent ions of main group metals versus transition metals. PANa-co-PAM hydrogels containing low and high fractions of ionic groups are investigated in solutions of DI water, NaCl, CaCl2, and CuSO4 at concentrations ranging from 5 to 100 mM in order to understand 1) the transient or permanent nature of crosslinks produced in these networks by divalent counter-ions, 2) the role of polymer ionic content in these interactions, and 3) how these interactions scale with salt concentration. Gravimetric swelling and mechanical compression testing are employed to characterize water and salt-swollen hydrogels in order to develop guiding principles to control and manipulate material properties through polymer-counter-ion interactions. The work presented here confirms the formation of permanent crosslinks by transition metal ions, offers explanation for the behavioral discrepancy observed between ionic hydrogels and main group versus transition metal ions, and illustrates how such hydrogel properties scale with counter-ion concentration.

scholarly journals Metallo-Supramolecular Hydrogels from the Copolymers of Acrylic Acid and 4-(2,2′:6′,2″-terpyridin-4′-yl)styrene

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1152 ◽  
Author(s):  
Huiqin Zhang ◽  
Pan Liu ◽  
Zheng Chi ◽  
Xuegang Chen
Keyword(s):  
Transition Metal ◽  
Acrylic Acid ◽  
Metal Ions ◽  
Self Assembly ◽  
Wavelength Region ◽  
Transition Metal Ions ◽  
Ion Concentration ◽  
Iron Ions ◽  
Absorption Intensity ◽  
Dilute Aqueous Solution

Hydrophilic copolymers containing 2,2′:6′,2″-terpyridine moieties and acrylic acid (AA) units poly (acrylic acid-co-4-(2,2′:6′,2″-terpyridin-4′-yl)styrene) (P(AA-co-TPY)) were synthesized and characterized. Coordinated with different transition metal ions, the dilute aqueous solution of the copolymers exhibited red-shifted UV-vis absorption peaks of π-π* transition from 317 to 340 nm. Further, interacting with iron ions, the copolymer showed new absorption peaks at a longer wavelength region (570 nm) and the absorption intensity enhanced with increase of the ion concentration. When enough ions were added to coordinate with the 2,2′:6′,2″-terpyridine moieties, novel metallo-supramolecular hydrogels were obtained due to the formation of metal coordination bonds between polymer back bones and transition metal ions (Ni2+, Zn2+, Cd2+, Fe2+ and Cu2+), which acted as self-assembly crosslinking structures. The mechanical strength and morphology of the resulting metallo-supramolecular hydrogels have been investigated.

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 Exploring the applicability of density functional tight binding to transition metal ions. Parameterization for nickel with the spin‐polarized DFTB3 model

2018 ◽  
Vol 40 (2) ◽  
pp. 400-413 ◽  
Author(s):  
Milena Vujović ◽  
Mioy Huynh ◽  
Sebastian Steiner ◽  
Pablo Garcia‐Fernandez ◽  
Marcus Elstner ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Density Functional ◽  
Tight Binding ◽  
Transition Metal Ions ◽  
Spin Polarized
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