Semiconducting Polymers Containing Coordinated Metal Ions

1962 ◽  
Vol 15 (4) ◽  
pp. 653 ◽  
Author(s):  
BA Bolto ◽  
DE Weiss
Keyword(s):  
Metal Ions ◽  
Coordination Polymers ◽  
Metal Ion ◽  
Metal Salt ◽  
Chloride Ion ◽  
Semiconducting Polymers ◽  
Cross Linking ◽  
Preparation Temperature ◽  
Phenazine Derivative ◽  
Polycyclic System

Ligands of the bis-(8-hydroxyquinoline) type were selected for the preparation of semiconducting coordination polymers. After some preliminary investigations in solvents, melt techniques with reaction temperatures of at least 250°C were found to be necessary for the formation of a conducting product from chloranil, o-phenylene- diamine, and a metal salt, which is postulated to involve polycoordination of a quinoxalo- phenazine derivative. Of 13 different metals studied, the FeCl2 polymer was found to be the best conductor, having a resistivity of 38 kΩ cm with a preparation temperature of 350°C, the resistivity remaining at this level for preparation temperatures up to 450°C. Studies of the reactions of the FeCl2 and FeCl3 polymers suggest intermolecular linking other than through the metal, a t least two types of organic cross-linking being evident. The presence of phenazinium salt structures in both polymers is postulated to account for the large amounts of chloride ion liberated by alkali. The conducting properties are attributed to interaction between donor nitrogens and acceptor groups such as the metal ion, quinones, and quaternary nitrogens linked within a fully conjugated polycyclic system. The existence of the metal in more than one oxidation state, which might occur with the FeCl2 polymer, may be of further benefit.

Two isostructural linear coordination polymers: the size of the metal ion impacts the electrical conductivity

2018 ◽  
Vol 42 (12) ◽  
pp. 10309-10316 ◽  
Author(s):  
Basudeb Dutta ◽  
Arka Dey ◽  
Kaushik Naskar ◽  
Suvendu Maity ◽  
Faruk Ahmed ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Metal Ions ◽  
Coordination Polymers ◽  
Metal Ion ◽  
Linear Coordination

Electrical conductivity was tuned by altering the metal ions in acetylenedicarboxylate (adc) and 4-styrylpyridine (4-spy)-based 1D coordination polymers, {[M(adc)(4-spy)2(H2O)2]}n (M = Zn and Cd).

New homodinuclear tris(3-alkylpyrazolyl)borate complexes of CoIIand NiIIwith a tetraacetylethane dianion as a bridging ligand

2016 ◽  
Vol 72 (11) ◽  
pp. 777-785
Author(s):  
Elena A. Mikhalyova ◽  
Swiatoslaw Trofimenko ◽  
Matthias Zeller ◽  
Anthony W. Addison ◽  
Vitaly V. Pavlishchuk
Keyword(s):  
Metal Ions ◽  
Coordination Polymers ◽  
Metal Ion ◽  
Molecular Structures ◽  
Polynuclear Complexes ◽  
X Ray ◽  
X Ray Crystallography ◽  
Coordination Sites ◽  
Borate Complexes ◽  
Capping Ligands

Polynuclear complexes and coordination polymers of 3dmetals have attracted significant interest evoked by a number of their unique properties. One of the most common approaches to the directed synthesis of coordination polymers is the linking of pre-prepared discrete coordination units by polydentate ligands. The formation of polynuclear complexes is usually a spontaneous process and precise prediction of the products of such reactions is virtually impossible in most cases. Tris(pyrazolyl)borates (Tp) act as tripodal `capping' ligands which form stable complexes with 3dmetal ions. In such 1:1 compounds, three metal-ion coordination sites are occupied by N atoms from a Tp anion. This limits the number of remaining coordination sites, and thus the number of additional ligands which may coordinate, and opens an attractive approach for the directed design of desirable structures by exploiting ligands with appropriate composition and topology. In the present study, Tp anions with neopentyl [TpNp, tris(3-neopentylpyrazolyl)borate] and cyclohexyl [TpCy, tris(3-cyclohexylpyrazolyl)borate] substituents were used as `capping' ligands and the dianion of tetraacetylethane (3,4-diacetylhexa-2,4-diene-2,5-diolate, tae2−) was employed as a bridge. The dinuclear complexes (μ-3,4-diacetylhexa-2,4-diene-2,5-diolato-κ4O2,O3:O4,O5)bis{[tris(3-cyclohexyl-1H-pyrazol-1-yl-κN2)borato]cobalt(II)} acetonitrile disolvate, [Co2(C27H40BN6)2(C10H12O4)]·2CH3CN, (I)·2CH3CN, and (μ-3,4-diacetylhexa-2,4-diene-2,5-diolato-κ4O2,O3:O4,O5)bis{[tris(3-neopentyl-1H-pyrazol-1-yl-κN2)borato]nickel(II)}, [Ni2(C24H40BN6)2(C10H12O4)], (II), were synthesized by the reaction of the mononuclear complexes TpCyCoCl or TpNpNiCl with H2tae (3,4-diacetylhexane-2,5-dione or tetraacetylethane) in the presence of NEt3as base. Compounds (I) and (II) were characterized by mass spectrometry, elemental analysis, and X-ray crystallography. They possess similar molecular structures, X-ray diffraction revealing them to be dinuclear in nature and composed of discrete Tp–Munits in which two metal ions are linked by a tae2−dianion. Each metal ion possesses a five-coordinate square-pyramidal environment. The interplanar angles between the acetylacetonate fragments are significantly smaller than the near-90° values commonly observed.

Chiral Preferences in the Dissociation of Homogeneous Amino Acid/Metal Ion Clusters

2002 ◽  
Vol 8 (2) ◽  
pp. 107-115 ◽  
Author(s):  
W. Andy Tao ◽  
R. Graham Cooks ◽  
Eugene N. Nikolaev
Keyword(s):  
Amino Acid ◽  
Metal Ions ◽  
Metal Ion ◽  
Metal Salt ◽  
Branching Ratio ◽  
Transition Metal Ions ◽  
Tandem Mass ◽  
Dissociation Process ◽  
Tandem Mass Spectra ◽  
Chiral Effects

Collision-induced dissociation (CID) of alanine or phenylalanine aggregates with various cations, including the proton, alkali metal ions, calcium and zinc, as well as the transition metals Co(II), Ni(II) and Cu(II), has been studied by tandem mass spectrometry. In these experiments, an isotopically labeled, chirally-pure amino acid (L-Ala-d3 and L-Phe-d5) is mixed with its unlabeled enantiomer and a metal salt and the clusters generated by electrospray ionization are mass-selected and subjected to CID. The relative stability of the precursor ions, as well as product-ion abundance ratios in the tandem mass spectra, are used as indicators of chiral effects on the dissociation process. It is shown that the stability of alanine aggregates during the kinetic dissociation process is independent of chirality, whereas a large chiral effect ( Rchiral ranging from 0.31 to 8.1) is observed for the clusters assembled from phenylalanine and transition metal ions. When two bulky phenylalanine molecules are covalently bound to a metal ion, the heterochiral cluster is more stable than the homochiral one. Clusters containing three or four phenylalanine molecules are loosely bound to the core ion and the homochiral cluster is more stable than the heterochiral one. It is suggested that non-covalent interactions, in particular π-cation interactions, are significant contributors to the large chiral effects. It is further suggested that the relationship between the branching ratio in the tandem mass spectrum and chirality can be used to determine the absolute configuration of chiral molecules.

Synthesis, crystal structure and biological properties of Cd and Zn coordination polymers based on a flexible tripodal ligand

2019 ◽  
Vol 75 (7) ◽  
pp. 1002-1010 ◽  
Author(s):  
Xia Wang ◽  
Ning Ling ◽  
Hanbing Li ◽  
Xiaohe Xiao ◽  
Yawen Zhang
Keyword(s):  
Metal Ions ◽  
Coordination Polymers ◽  
Metal Ion ◽  
Radical Scavenging ◽  
Antidiabetic Activity ◽  
Distorted Octahedral Geometry ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Methyl Benzene

Two new coordination polymers, namely poly[[hexathiocyanatotetrakis{μ3-2,4,6-trimethyl-1,3,5-tris[(triazol-1-yl)methyl]benzene}tricadmium(II)] 3.5-hydrate], {[Cd3(SCN)6(C18H21N9)4]·3.5H2O} n (1), and poly[[hexathiocyanatotetrakis{μ3-2,4,6-trimethyl-1,3,5-tris[(triazol-1-yl)methyl]benzene}trizinc(II)] 3.5-hydrate], {[Zn3(SCN)6(C18H21N9)4]·3.5H2O} n (2), have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction analysis. From the X-ray analysis, it is noteworthy that polymers 1 and 2 are isostructural, with their three-dimensional structures composed of three kinds of four-connection metal ions and two kinds of three-connection 2,4,6-trimethyl-1,3,5-tris[(triazol-1-yl)methyl]benzene (TTTMB) ligand nodes. Each metal ion is six-coordinated in a slightly distorted octahedral geometry. The antioxidant activity against DPPH (2,2-diphenyl-1-picrylhydrazyl) and the antidiabetic activity against α-amylase of the synthesized compounds were evaluated in vitro. The results of the DPPH free-radical scavenging assay showed that polymers 1 and 2 exhibited strong antioxidant effects, with IC50 values of 3.81 and 2.56 mg ml−1, respectively. The IC50 value in the antidiabetic studies of polymer 1 was 3.94 mg ml−1, while polymer 2 exhibited no antidiabetic activity. Polymers 1 and 2 revealed different inhibitory activities on DPPH and α-amylase, which indicated that the metal ions play important roles in the biological activity of coordination polymers. In addition, the solid-state photoluminescence properties and thermal stability of 1 and 2 have been investigated.

Alkaline-earth and aminonicotinate based coordination polymers with combined fluorescence/long-lasting phosphorescence and metal ion sensing response

2019 ◽  
Vol 7 (23) ◽  
pp. 6997-7012 ◽  
Author(s):  
Oier Pajuelo-Corral ◽  
Antonio Rodríguez-Diéguez ◽  
Garikoitz Beobide ◽  
Sonia Pérez-Yáñez ◽  
Jose A. García ◽  
...  
Keyword(s):  
Metal Ions ◽  
Coordination Polymers ◽  
Metal Ion ◽  
Alkaline Earth ◽  
Blue Fluorescence ◽  
Ion Sensing ◽  
Metal Ion Sensing ◽  
Bright Blue Fluorescence ◽  
Bright Blue

Alkaline-earth and aminonicotinate based CPs exhibit green long lasting phosphorescence and bright blue fluorescence responsive to metal ions.

Use of agro-waste (Musa paradisiaca peels) as a sustainable biosorbent for toxic metal ions removal from contaminated water

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Contact Time ◽  
Metal Ion ◽  
Equilibrium Concentration ◽  
Ion Concentration ◽  
Contaminated Water ◽  
Musa Paradisiaca ◽  
Percentage Removal ◽  
Adsorbent Dose

A study of removal of heavy metal ions from heavy metal contaminated water using agro-waste was carried out with Musa paradisiaca peels as test adsorbent. The study was carried by adding known quantities of lead (II) ions and cadmium (II) ions each and respectively into specific volume of water and adding specific dose of the test adsorbent into the heavy metal ion solution, and the mixture was agitated for a specific period of time and then the concentration of the metal ion remaining in the solution was determined with Perkin Elmer Atomic absorption spectrophotometer model 2380. The effect of contact time, initial adsorbate concentration, adsorbent dose, pH and temperature were considered. From the effect of contact time results equilibrium concentration was established at 60minutes. The percentage removal of these metal ions studied, were all above 90%. Adsorption and percentage removal of Pb2+ and Cd2+ from their aqueous solutions were affected by change in initial metal ion concentration, adsorbent dose pH and temperature. Adsorption isotherm studies confirmed the adsorption of the metal ions on the test adsorbent with good mathematical fits into Langmuir and Freundlich adsorption isotherms. Regression correlation (R2) values of the isotherm plots are all positive (>0.9), which suggests too, that the adsorption fitted into the isotherms considered.

The Binding and Viscometric Studies of Ni+2, Co+2 and Mn+2 Ions with Protein by Spectrometric and pH Metric Techniques

2019 ◽  
Vol 9 (2) ◽  
pp. 151-162
Author(s):  
Shveta Acharya ◽  
Arun Kumar Sharma
Keyword(s):  
Metal Ions ◽  
Metal Ion ◽  
Protein Molecule ◽  
Vital Role ◽  
Sufficient Evidence ◽  
Structural Requirement ◽  
Nickel Ions ◽  
Cobalt Ions ◽  
Lower Temperature ◽  
Specific Oxidation

Background: The metal ions play a vital role in a large number of widely differing biological processes. Some of these processes are quite specific in their metal ion requirements. In that only certain metal ions, in specific oxidation states, can full fill the necessary catalytic or structural requirement, while other processes are much less specific. Objective: In this paper we report the binding of Mn (II), Ni (II) and Co (II) with albumin are reported employing spectrophotometric and pH metric method. In order to distinguish between ionic and colloidal linking, the binding of metal by using pH metric and viscometric methods and the result are discussed in terms of electrovalent and coordinate bonding. Methods: The binding of Ni+2, Co+2 and Mn+2 ions have been studied with egg protein at different pH values and temperatures by the spectrometric technique. Results: The binding data were found to be pH and temperature dependent. The intrinsic association constants (k) and the number of binding sites (n) were calculated from Scatchard plots and found to be at the maximum at lower pH and at lower temperatures. Therefore, a lower temperature and lower pH offered more sites in the protein molecule for interaction with these metal ions. Statistical effects seem to be more significant at lower Ni+2, Co+2 and Mn+2 ions concentrations, while at higher concentrations electrostatic effects and heterogeneity of sites are more significant. Conclusion: The pH metric as well as viscometric data provided sufficient evidence about the linking of cobalt, nickel and manganese ions with the nitrogen groups of albumin. From the nature and height of curves in the three cases it may be concluded that nickel ions bound strongly while the cobalt ions bound weakly.

Metal-organic Nanopharmaceuticals

2020 ◽  
Vol 8 (3) ◽  
pp. 163-190
Author(s):  
Benjamin Steinborn ◽  
Ulrich Lächelt
Keyword(s):  
Metal Ions ◽  
Coordination Polymers ◽  
Active Agent ◽  
Lewis Base ◽  
High Loading ◽  
Active Components ◽  
Base Functions ◽  
Metal Organic ◽  
Theranostic Applications ◽  
Pharmacologically Active

: Coordinative interactions between multivalent metal ions and drug derivatives with Lewis base functions give rise to nanoscale coordination polymers (NCPs) as delivery systems. As the pharmacologically active agent constitutes a main building block of the nanomaterial, the resulting drug loadings are typically very high. By additionally selecting metal ions with favorable pharmacological or physicochemical properties, the obtained NCPs are predominantly composed of active components which serve individual purposes, such as pharmacotherapy, photosensitization, multimodal imaging, chemodynamic therapy or radiosensitization. By this approach, the assembly of drug molecules into NCPs modulates pharmacokinetics, combines pharmacological drug action with specific characteristics of metal components and provides a strategy to generate tailorable multifunctional nanoparticles. This article reviews different applications and recent examples of such highly functional nanopharmaceuticals with a high ‘material economy’. : Lay Summary: Nanoparticles, that are small enough to circulate in the bloodstream and can carry cargo molecules, such as drugs, imaging or contrast agents, are attractive materials for pharmaceutical applications. A high loading capacity is a generally aspired parameter of nanopharmaceuticals to minimize patient exposure to unnecessary nanomaterial. Pharmaceutical agents containing Lewis base functions in their molecular structure can directly be assembled into metal-organic nanopharmaceuticals by coordinative interaction with metal ions. Such coordination polymers generally feature extraordinarily high loading capacities and the flexibility to encapsulate different agents for a simultaneous delivery in combination therapy or ‘theranostic’ applications.

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