Electrochemical and Adsorption Properties of Novel Phthalocyanines with Four 16-Membered Diazadithia Macrocycles

1998 ◽  
Vol 02 (06) ◽  
pp. 483-492 ◽  
Author(s):  
A. R. ÖZKAYA ◽  
İ YILMAZ ◽  
Ö. BEKAROǦLU
Keyword(s):  
Aqueous Medium ◽  
Copper Ions ◽  
Mixed Valence ◽  
Adsorption Properties ◽  
Oxidation Peak ◽  
Cyclic Voltammetric ◽  
Working Electrode ◽  
Strong Adsorption ◽  
Voltammetric Measurements

Cyclic voltammetric measurements of Cu (II) and Ni (II) phthalocyanines with four 16-membered diazadithia macrocycles (1 and 2) and pentanuclear Ni (II) phthalocyanine bearing four Cu (II) ions in diazadithia macrocycles at the peripheral positions (3) have been carried out on platinum in DMSO and in aqueous medium 3 showed strong adsorption properties in DMSO and especially in aqueous medium, possibly as a result of the interaction between the copper ions in the four macrocycles and the platinum working electrode. Interestingly, the oxidation peak of 3 was split into two waves in aqueous medium. This behaviour is discussed in terms of disaggregation of the mixed valence species produced by the oxidation of aggregated species. A mechanism for both the oxidation of the complex and the splitting of the oxidation peak into two waves is suggested.

scholarly journals Studies on the Complexation of Succinic Hydrazide with Copper Chloride Salt

2021 ◽  
Vol 2 (1) ◽  
pp. 14-20
Author(s):  
Shereen E. Salem ◽  
Esam A. Gomaa ◽  
Mohamed M. El-Defrawy ◽  
Noha M. Ebrahem
Keyword(s):  
Copper Ions ◽  
Copper Chloride ◽  
Hydroxyl Group ◽  
Chloride Salt ◽  
Gram Negative Bacteria ◽  
Free Energies ◽  
Cyclic Voltammetric ◽  
Different Types ◽  
Bacteria And Fungi ◽  
Voltammetric Measurements

The electrochemical behavior of the complexation between copper chloride salt and succinic hydrazide can be explained using cyclic voltammetric measurements. The complex is formed through the interaction with nitrogen and hydroxyl group or carbonyl group of succinic hydrazides. This interaction can be observed by decreasing in the height peak of current and measuring the (anodic/cathodic) shift of the potentials. All the solvation and thermodynamic parameters for the interaction of copper ions with succinic hydrazide as stability constant, Gibbs free energies, enthalpies and entropies of interaction were calculated. Finally, the activity of the formed complex was compared with the succinic hydrazide by comparing their effects on different types of gram-negative bacteria and fungi indicating high activity of the formed complex and its ability to be used in different medical applications.

Synthesis, characterisation and activity in catalytic epoxidation of olefins of new dinuclear nickel(ll) complexes

2009 ◽  
Vol 2009 (8) ◽  
pp. 527-532
Author(s):  
Manindranath Bera
Keyword(s):  
Visible Region ◽  
Chemical Oxidation ◽  
Cyclic Voltammetric ◽  
Catalytic Epoxidation ◽  
Redox Couples ◽  
Square Planar ◽  
Catalytically Active ◽  
Mecn Solution ◽  
Voltammetric Measurements ◽  
Epoxidation Of Olefins

Two new dinuclear nickel(ll) compounds of formula [Nill2(μ-L1)2](CIO4)2·MeCN (1·MeCN) and [NiII2(μ-L2)2](CIO4)2 (2) where HL1 and HL2 stand for 3-(2-(dimethylamino)ethylimino)butan-2-one oxime and 1-(2-(dimethylamino)ethyl-imino)-1-phenylpropan-2-one oxime respectively, have been synthesised. Single crystal X-ray analyses of the complexes reveal that the nickel(ll) ions are in square-planar N3O environments and form six-membered (NiNO)2 metallacycles. Cyclic voltammetric measurements of 1·MeCN and 2 in MeCN solution show quasirreversible one-electron oxidations at E1/2 = 0.566 V and 0.603 V ( vs Fc+/Fc), respectively, attributed to NiIIINiII/NiII2 redox couples. Additional reversible NiIII2/NiIIINiII redox responses were observed at relatively higher potential near E1/2 = 0.832 V and 0.850 V ( vs Fc+/Fc), respectively, for 1·MeCN and 2. Complexes 1·MeCN and 2 display intense charge-transfer bands at ∼390 and ∼345 nm in the visible region. Chemical oxidation of complex 1·MeCN by sodium hexachloroiridate(IV) hexahydrate generates red Ni2III species with characteristic new bands at ∼520 and 427 nm in the visible region as well as the characteristic EPR signals at 77 K with g⊥ > gII. Similar phenomena were observed for complex 2 upon chemical oxidation. The dinickel(ll) complexes are catalytically active for epoxidation of olefins using iodosylbenzene as the terminal oxidant.

scholarly journals Cobalt(II) complexes with aromatic carboxylates and N-functionalized cyclam bearing 2-pyridylmethyl pendant arms

2005 ◽  
Vol 70 (8-9) ◽  
pp. 1121-1129 ◽  
Author(s):  
Gordana Vuckovic ◽  
V. Stanic ◽  
Sofija Sovilj ◽  
M. Antonijevic-Nikolic ◽  
J. Mrozynski
Keyword(s):  
Cyclic Voltammetry ◽  
Ir Spectroscopy ◽  
Chair Conformation ◽  
Trans Position ◽  
Cyclic Voltammetric ◽  
Aromatic Carboxylates ◽  
Elemental Analyses ◽  
Electrical Conductivities ◽  
Pendant Arms ◽  
Voltammetric Measurements

Novel binuclear Co(II) complexeswithN-functionalized cyclam N,N?,N",N???-tetrakis( 2-pyridylmethyl)tetraazacyclotetradecane (tpmc) and one of the aromatic monoor dicarboxylato ligands (benzoate, phthalate or isophthalate ions) were prepared. They were analyzed and studied by elemental analyses (C, H, N), electrical conductivities, VIS and IR spectroscopy andmagnetic as well as cyclic voltammetric measurements. In [Co2(C6H5COO)2tpmc]ClO4)2.3H2O, the benzoate ligands are most probably coordinated as chelates in the trans-position to each Co(II) and the macrocycle adopts a chair conformation. In the complexes [Co2(Y)tpmc]ClO4)2.zH2O, (Y = phthalate or i-phthalate dianizon, z = 2; 4) it is proposed that the isomeric dicarboxylates are bonded combined as bridges and chelates. The composition and the assumed geometries of the complexes are compared with the, earlier reported, corresponding Cu(II) complexes. Cyclic voltammetry measurements showed that the compounds are electrochemically stable.

Role of Oxidation-Reduction Processes in Formation of Toxic Properties of Natural Aqueous Environment

2020 ◽  
pp. 149-163
Author(s):  
Yuri Ivanovich Skurlatov ◽  
Elena Valentinovna Shtamm ◽  
Sergey Olegovich Travin ◽  
Vyacheslav Olegovich Shvydkiy ◽  
Lyudmila Vasilevna Semenyak
Keyword(s):  
Green Alga ◽  
Natural Waters ◽  
Copper Ions ◽  
Dynamic Change ◽  
Mixed Valence ◽  
Anthropogenic Source ◽  
Aqueous Environment ◽  
Blue Green Alga ◽  
Reduced Sulfur Compounds ◽  
Oxidation Reduction

Redox processes involving hydrogen peroxide, as oxidizing agent, and compounds of sulfur as carrier of reducing equivalents form the quality of natural waters. The inflow of reductants interacting with H2O2 can lead to a toxic quasi-reductive state. Dynamic change of redox in a natural aqueous medium is pernicious for organisms with intensive water-exchange, such as larvae of fishes, despite the concentration of dissolved oxygen being normal. Favorable conditions for “flowering” of emerging toxins blue-green alga are formed. In reductive state, copper ions become biologically unavailable. Sewage after biological cleaning are the main anthropogenic source of the reductants, mainly hydrosulphide. The natural sources of reductants are blue-green alga and the bottom sediments. The ions of Cu(I) and Fe(II) form high-strength 1:1 complexes with reduced sulfur compounds that are stable to O2 but efficiently react with H2O2. The increased content of manganese can form mixed-valence manganese species Mn(III,IV) giving super-oxidizing state of the aquatic environment, which is also toxic.

STRUCTURAL INVESTIGATIONS OF CuO–B2O3–Bi2O3 GLASSES BY MEANS OF EPR AND FT-IR SPECTROSCOPIES

2004 ◽  
Vol 18 (16) ◽  
pp. 803-810 ◽  
Author(s):  
I. ARDELEAN ◽  
SIMONA CORA ◽  
RALUCA CICEO-LUCACEL
Keyword(s):  
Local Structure ◽  
Copper Content ◽  
Copper Ions ◽  
Glass Structure ◽  
Mixed Valence ◽  
Structural Investigations ◽  
Valence States ◽  
Distorted Octahedral ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

EPR and FT-IR spectroscopy have been used to investigate the B 2 O 3– Bi 2 O 3 glass matrix containing CuO in order to obtain more information about the local structure of these glasses. The EPR absorption spectra revealed the presence in the glass structure of the Cu 2+ ions in axially distorted octahedral environments. No superexchange interaction of Cu 2+ was detected. In the samples with x≥5 mol%, mixed valence states of copper ions were revealed. The FT-IR measurements indicate the presence in the glass structure of the distorted [ BiO 6] polyhedra, tri- and tetra-borate units ( BO 3, BO 4) and its dependence by the copper content.

Preparation and copper ions adsorption properties of thiosemicarbazide chitosan from squid pens

2017 ◽  
Vol 95 ◽  
pp. 476-483 ◽  
Author(s):  
Yue-cheng Lin ◽  
Hong-peng Wang ◽  
Faryal Gohar ◽  
Muhammad Haseeb Ullah ◽  
Xiang Zhang ◽  
...  
Keyword(s):  
Copper Ions ◽  
Adsorption Properties

A novel electrochemical sensor for capsaicin based on mesoporous cellular foams

2015 ◽  
Vol 7 (3) ◽  
pp. 1167-1174 ◽  
Author(s):  
Zhonghua Xue ◽  
Chenxian Hu ◽  
Honghong Rao ◽  
Xuemei Wang ◽  
Xibin Zhou ◽  
...  
Keyword(s):  
Electrochemical Sensor ◽  
Surface Area ◽  
High Sensitivity ◽  
Large Surface Area ◽  
Sensitive Material ◽  
Working Electrode ◽  
Cellular Foams ◽  
Strong Adsorption

A novel electrochemical sensor for capsaicin using mesoporous cellular foams (MCFs) as sensitive material is reported. The high sensitivity of the proposed sensor is attributed to the strong adsorption of capsaicin by mesoporous cellular foams and large surface area of the working electrode resulting from MCFs modification.

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