Search results for "Perchlorate"
showing 10 items of 643 documents
The role of lithium, perchlorate and water during electrochemical processes in poly(3,4-ethylenedioxythiophene) films in LiClO4 aqueous solutions
2021
Abstract Thin films of poly(3,4-ethylendioxythiophene) (PEDOT) were electrochemically deposited on gold electrodes in aqueous media. The role of perchlorate, lithium, and water during the charge/discharge of PEDOT films was investigated by cyclic voltammetry together with EQCM, vis − NIR spectroscopy, and acoustic impedance, also by means of ac-electrogravimetry in a 0.1 M LiCl O 4 aqueous solutions. In this way, it has been possible to correlate the electrical, mass, color and electromechanical properties changes during the electrochemical reactions of this polymer. Both, hydrated lithium cations and perchlorate anions can act as counterions during the electrochemical reactions, however, a…
Electrochemical and spectroscopic studies of poly(diethoxyphosphoryl)porphyrins
2011
Abstract The synthesis and electrochemical characterization of two related series of porphyrins bearing diethoxyphosphoryl groups are reported. One group of compounds is represented as (T( p -R)PP)M where R = phos = P(O)(OEt) 2 and M = Zn(II) or H 2 while the other is represented as (di( p -R)Pdi(phos)P)M where R = P(O)(OEt) 2 , H or CH 3 and M = Zn(II) or H 2 . Each porphyrin was investigated by electrochemistry and thin-layer spectroelectrochemistry in CH 2 Cl 2 , CDCl 3 , CHCl 3 or PhCN containing tetra- n -butylammonium perchlorate (TBAP) as supporting electrolyte. The highly electron-withdrawing P(O)(OEt) 2 groups lead to easier reductions and harder oxidations than the two comparison …
Homo- and heterobinuclear Cu2+ and Zn2+ complexes of abiotic cyclic hexaazapyridinocyclophanes as SOD mimics
2013
The new receptor 3,7,11,15,19,23-hexaaza-1(2,6)-pyridinacyclotetracosaphane (L1) containing a complete sequence of propylenic chains has been synthesised. The acid–base behaviour and Cu2+ and Zn2+ coordination have been analysed by potentiometric measurements in 0.15 M NaClO4 for L1 and for the related compounds 3,7,11,14,18,22-hexaaza-1(2,6)-pyridinacyclotricosaphane (L2), 3,7,10,13,16,20-hexaaza-1(2,6)-pyridinacycloheneicosaphane (L3) and 3,7,10,12,15,19-hexaaza-1(2,6)-pyridinacycloicosaphane (L4). The crystal structure of [(CuH4L2)(H2O)(ClO4)](ClO4)5·3H2O shows an interesting combination of a metal ion coordinated by the pyridine nitrogen atom and the adjacent amine groups of the chain, …
The First Examples of a Crown Ether Intramolecularly Encapsulating Mono- and Diorganotin Dications: Synthesis and Structures of [PhSnCH2([16]crown-5)…
2010
The reaction of silver perchlorate with [PhI 2 SnCH 2 ([16]crown-5)] (1) and [I 3 SnCH 2 ([16]crown-5)] (2) gave the organotin(IV)-substituted crown ether complexes [PhSnCH 2 ([16]crown-5)][ClO 4 ] 2 (3) and [HOSnCH 2 ([16]crown-5)][Y] 2 (4: Y= ClO 4 , 5: Y=CF3 S 03 ) , respectively. All compounds have been isolated as air-stable materials and characterised by 1 H, 13 C, 119 Sn and 119 Sn MAS (5) NMR spectroscopy, ESIMS spectrometry, elemental analysis and by single-crystal X-ray diffraction analysis. The molecular structures of 3-5 show that the tin(IV) cation fits perfectly into the crown ether cavity and is coordinated by the five oxygen atoms of the ring to give a pentagonal bipyramidal…
Polynuclear copper(II) complexes with hexadentate Schiff base directed by the counter ion. Syntheses, crystal structures and magnetic properties
2018
Abstract Four new complexes, [Cu 9 L 6 ( µ 3 -ClO 4 ) 2 ](ClO 4 ) 4 ·4CHCl 3 1 , [Cu 3 L 2 (H 2 O) 2 ](ClO 4 ) 2 ·3H 2 O 2 , [Cu 6 L 4 (N 3 ) 2 ](ClO 4 ) 2 3 and [Cu 2 L(CH 3 COO) 2 ] 4 , where H 2 L stands for the Schiff base N , N ′-bis[(2-hydroxybenzilideneamino)-propyl]-piperazine, were obtained and structurally characterized. Compounds 1 , 2 and 3 contain the Cu 3 L 2 2+ entities in which L 2− acts in an unsymmetrical mode with N 3 O donor set wrapped around marginal copper(II) and with the remained NO sets bound to the central copper ion. The marginal copper(II) ions are in distorted square pyramidal environment, whereas that of the central one is square planar. In 1 , the peripheral …
Clarification of the oxidation state of cobalt corroles inheterogeneous and homogeneous catalytic reduction of dioxygen
2008
Co(III) corroles were investigated as efficient catalysts for the reduction of dioxygen in the presence of perchloric acid in both heterogeneous and homogeneous systems. The investigated compounds are (5,10,15-tris(pentafluorophenyl)corrole)cobalt (TPFCor)Co, (10-pentafluorophenyl-5,15-dimesitylcorrole)cobalt (F 5PhMes 2Cor)Co, and (5,10,15-trismesitylcorrole)cobalt (Mes 3Cor)Co, all of which contain bulky substituents at the three meso positions of the corrole macrocycle. Cyclic voltammetry and rotating ring-disk electrode voltammetry were used to examine the catalytic activity of the compounds when adsorbed on the surface of a graphite electrode in the presence of 1.0 M perchloric acid, a…
ChemInform Abstract: Formation in Solution, Synthesis and Crystal Structure of μ-Oxalatobis(bis(2-pyridylcarbonyl)amido)dicopper(II).
1989
Abstract The compound μ-oxalatobis[bis(2-pyridylcarbonyl)amido] dicopper(II), [Cu 2 {(NCsH 5 CO) 2 N} 2 - (C 2 O 4 )] was synthesized and characterized by spectroscopy, EPR and diffraction methods. It crystallizes in the triclinic space group P 1 with cell constants: a =7.6793(6), b =9.238(2), c =10.007(2) A, α=83.80(1), β=68.37(1) and γ=69.44(1)°; V =617.7(3) A 3 , D (calc., Z =2)=1.80 g cm −3 , M r =667.6, F (000)=336, λ, (Mo Kα)=0.71069 A, μ (Mo Kα)=17.895 cm −1 and T =295 K. A total of 3587 data were collected over the range of 1 ⩽ θ ⩽ 30°; of these, 2391 (independent and with I⩾2σ( I )) were used in the structural analysis. The final R and R w residuals were 0.049 and 0.053, respective…
Discriminating octahedral transition metal ions: highly selective tripodal tris-(2,2′-bipyridine) functionalized piperazine cyclophane receptor for C…
2011
New tripodal transition metal ion receptors, tris(5-ethoxycarbonyl-2,2'-bipyridine) and tris(5-carboxylate-2,2'-bipyridine) substituted 27-membered trimeric piperazine cyclophanes 5 and 7 as well as tetra(5-ethoxycarbonyl-2,2'-bipyridine) substituted 36-membered tetrameric piperazine cyclophane 6, have been prepared and their transition metal ion complexing properties studied in solution by UV-vis spectroscopy and in the solid state by single-crystal X-ray diffraction. The crystal structures of [H(3)5(3+)·Fe(2+)]·4(ClO(4)(-))·CF(3)COO(-) (V), [H(3)7(2+)·Fe(2+)]·2(SO(4)(2-)) (VII) and the reference complex [tris(5,5'-bis(ethoxycarbonyl)-2,2'-bipyridine)Fe(II) perchlorate] (I) showed that the…
Structural Diversity due to Amino Alcohol Ligands Leading to Rare μ4-Hydroxo-Bridged Tetranuclear and “Bicapped Cubane” Cores in Copper(II) Complexes…
2013
The μ4-hydroxo- and alkoxo-bridged tetranuclear copper(II) complexes, [Cu4(μ4-OH)(dmae)4][Ag(NO3)4] (1), [Cu4(μ4-OH)(dmae)4][Na(NO3)4] (2), [Cu4(μ4-OH)(dmae)4][K(NO3)4] (3), and hexanuclear alkoxo-bridged "bicapped cubane" copper(II) complex [Cu6(ae)8(ClO4)2](ClO4)2·MeOH (8) (dmae = N,N-dimethylaminoethanolato and ae = 2-aminoethanolato) were synthesized via self-assembly from chelating amino alcohols and copper(II), silver (1), sodium (2), and potassium (3) nitrates or copper(II) perchlorate (8). The complexes are characterized by elemental analyses, single-crystal X-ray diffraction, and variable temperature magnetic measurements. The crystal structures of complexes 1-3 consist of almost p…
Conductance in isodielectric mixtures. III.i-butyronitrile with chlorobenzene,o-dichlorobenzene,p-dichlorobenzene, 1,2-dichloroethane, andn-pentanol
1975
The conductance of tetrabutylammonium tetraphenylboride, picrate, perchlorate, and nitrate has been measured at 25°C in mixtures ofi-butyronitrile with chlorobenzene,o-dichlorobenzene,p-dicholorobenzene, 1,2-dichloroethane, andn-pentanol covering the range of dielectric constants 10≤D≤20. In these mixtures of polar solvents, both association constants and ionic mobilities depend on ion-solvent interaction energies and on free volume in a manner that is specific for each system. This failure of the primitive model (rigid charged spheres in a continuum) is shown to be the consequence of short-range spatial and energetic interactions between ions and adjacent solvent molecules.