The coordination of β-amino ketoximes with divalent iron, cobalt, nickel and zinc

1978 ◽  
Vol 31 (11) ◽  
pp. 2409 ◽  
Author(s):  
HKJ Powell ◽  
JM Russell
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Bonding ◽  
Stability Constant ◽  
Methyl Ether ◽  
Infrared Spectra ◽  
Iron Cobalt ◽  
Divalent Iron ◽  
Cobalt Nickel ◽  
Stability Order ◽  
The Stability

The iron(II), nickel(II) and zinc(II) complexes of the diamine dioxime ligand 4,4,9,9-tetramethyl-5,8-diazadodecane-2,11-dione dioxime (H2dddo) and the cobalt(II), nickel(II) and zinc(II) complexes of its O-methyl ether (Hddmo) have been studied potentiometrically at 25°C, I 0.10M NaCl. Stability constant data are compared with those obtained for the copper(II) and cobalt(II) complexes of H2dddo and the copper(II) complexes of Hddmo. H2dddo coordinates in the oxime-oximato form [M(Hdddo)]+ with iron(II), cobalt(II), nickel(II) and zinc(II) Hddmo forms complexes with the ligand coordinated in the oxime form [M(Hddmo)]2+ and the oximato form [M(ddmo)]+. The complexes [Zn(Hddmo)2]2+, [Zn(Hddmo)(ddmo)]+ and [Co(ddmo)(OH)] were also characterized in aqueous solution. The stability order FeII < CoII < NiII < CuII > ZnII was observed for the formation of 1 : 1 complexes with the ligands Hdddo- (log K = 8.8, 11.7, 15.2, 23.3, 12.0 for Fe to Zn respectively) and Hddmo (5.7, 6.6, 12.1, 5.3 for Co to Zn). The infrared spectra of the complexes [Ni(Hdddo)] ClO4,H2O and [Zn(Hdddo)] ClO4 are discussed in terms of oxime-oximato hydrogen bonding.

Complexes of 8-Amino-2-methylquinoline with divalent iron, cobalt, nickel, copper, and zinc sulphates

1970 ◽  
Vol 23 (7) ◽  
pp. 1375 ◽  
Author(s):  
MR Litzow ◽  
LF Power ◽  
AM Tait
Keyword(s):  
Infrared Spectra ◽  
Iron Cobalt ◽  
Divalent Iron ◽  
Cobalt Nickel ◽  
Copper And Zinc ◽  
Nickel Copper ◽  
Visible Spectra

The complexes formed by 8-amino-2-methylquinoline (maq) with iron(11), cobalt(11), nickel(11), copper(11), and zinc(11) sulphates have been prepared. The visible spectra, conductivities, and infrared spectra favour the assignment of dimeric octahedral stereochemistries for the copper(11) and zinc(11) complexes, involving ohelating sulphato groups. The complexes of iron(11), nickel(11), and cobalt(11) appear to be octahedral and monomeric with monodentate sulphato groups.

Evaluation of the stability constant of Cl2˙–in neutral aqueous solution

1995 ◽  
Vol 91 (18) ◽  
pp. 3303-3305 ◽  
Author(s):  
David J. Adams ◽  
Susan Barlow ◽  
George V. Buxton ◽  
Treena M. Malone ◽  
G. Arthur Salmon
Keyword(s):  
Aqueous Solution ◽  
Stability Constant ◽  
Neutral Aqueous Solution ◽  
The Stability

An assessment of oxime-oximato hydrogen bonding: A structural and thermodynamic study of copper(II) complexes

1978 ◽  
Vol 31 (4) ◽  
pp. 723 ◽  
Author(s):  
EA Daniel ◽  
FC March ◽  
HKJ Powell ◽  
WT Robinson ◽  
JM Russell
Keyword(s):  
Hydrogen Bonding ◽  
Methyl Ether ◽  
Complex Cation ◽  
Steric Effects ◽  
Apical Position ◽  
X Ray ◽  
Methyl Substitution ◽  
Perchlorate Ion ◽  
Nitrogen Donor ◽  
The Stability

Copper(II) complexes formed by the diamine dioxime ligand 4,4,9,9- tetramethyl-5,8-diazadodecane-2,11-dione dioxime (H2dddo) and its O-methyl ether (Hddmo) and bis-O-methyl ether (dddm) have been studied. The log K (potentiometric) and ΔH (calorimetric) values are reported for formation of the four-coordinate complexes [Cu(Hddmo)]2+ and [Cu(dddm)]2+ and for the deprotonation of [Cu(Hddmo)]2+ to give [Cu(ddmo)]+ at 25°C, I = 0.1 M NaCl. (log K = 12.11 � 0.04, 9.10�0.02 and -6.76�0.09; ΔH= -43�2, -17.9�0.4 and +21.9�0.9 kJ mol-1 respectively.) Comparison with data for [Cu(H2dddo)]2+ and [Cu(Hdddo)]+ affords information about the relative contributions of (i) oxime deprotonation (c. 105.6), and (ii) oxime oximato hydrogen bonding (c. 103.5), to the stability of these (non-conjugated) dioxime complexes. The formation of intramolecular (oxime-oximato) hydrogen bonds is favoured by a positive ΔS; intermolecular bonds (oximato-solvent) give rise to a negative ΔS. ��� A single-crystal X-ray molecular structure determination is reported for the complex Cu(dddm)-(ClO4)2. In the solid state the complex cation is square pyramidal with one perchlorate ion weakly coordinated in the apical position and the four nitrogen donor atoms forming a distorted square plane about the copper atom. Steric effects associated with O-methyl substitution are assessed. Steric hindrance between adjacent =NOR groups does not increase measurably when =NOH is replaced by =NOMe.

Study on Influence of Polyethylene Glycol on Dispersion of Pyrite Powder in Aqueous Solution

2012 ◽  
Vol 554-556 ◽  
pp. 349-352
Author(s):  
Dan Li ◽  
Zhou Lan Yin ◽  
Qi Yuan Chen
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Bonding ◽  
Polyethylene Glycol ◽  
Spectroscopic Analysis ◽  
Ph Value ◽  
Aqueous Suspension ◽  
Dispersion Stability ◽  
The Stability ◽  
High Degree ◽  
Effective Additive

The influences of three kinds of polyethylene glycol (PEG), namely PEG-200, PEG-1000 and PEG-20000, on the dispersion stability of pyrite powder in aqueous solution were investigated by spectrophotometry. The results indicated that the stability of pyrite powder dispersed in aqueous solution was remarkably dependent upon the molecular weight and content of PEG, pH value of suspension, and ultrasonication power. Among three kinds of polyethylene glycol, PEG-20000 was the most effective additive to improve the dispersion stability and wettability of pyrite powder in water. When 8% PEG-20000 was employed as the dispersant, the best dispersion stability of pyrite powder in aqueous solution could be obtained under the conditions of pH at 5-6 and 100-W ultrasonication power. The FTIR spectroscopic analysis showed that the adsorption between the polyethylene glycol and pyrite ore powder was formed by hydrogen bonding. The adsorption of polyethylene glycol onto the surface of pyrite powder via hydrogen bonding provided a high degree of steric stabilization, which effectively prohibited the aggregation of pyrite powder, and thus the dispersion stability of as-formed aqueous suspension was promoted.

scholarly journals Determination of the protonation state of [H3PW11O39]4− and the stability constant of [Ag(H2O)(H3PW11O39)]3− in aqueous solution

2016 ◽  
Vol 69 (17) ◽  
pp. 2525-2531 ◽  
Author(s):  
Jidan Wang ◽  
Jiansheng Li ◽  
Wansheng You ◽  
Chunxiang He ◽  
Zaiming Zhu
Keyword(s):  
Aqueous Solution ◽  
Stability Constant ◽  
Protonation State ◽  
The Stability

scholarly journals Modeling and Thermodynamic Values of Complex Equilibrium of Cobalt(II) with Diethylenetriaminepentaacetic Acid in Aqueous Solution

2021 ◽  
Author(s):  
Ghusoon Faidhi Hameed ◽  
Fawzi Yahya Waddai ◽  
Nahla Shakir Salman
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Complex Formation ◽  
Stability Constant ◽  
Wide Spectrum ◽  
Equilibrium Constants ◽  
Diethylenetriaminepentaacetic Acid ◽  
The Stability ◽  
Hoff Equation ◽  
Potentiometric Data

The paper reports the study of the complex formation of cobalt (II) with diethylenetriaminepentaacetic acid (DTPA, H5L) based on spectrophotometric (SF) and potentiometric data (pH). Complexes of different compositions were found, and equilibrium constants, as well as the stability constants of these complexes, were determined. Accumulation of complexes in proportion is calculated based on the acidity of the medium. The experimental data have been carried out by using mathematical models to assess the solution's possible existence with a wide spectrum of complex particles and to point out those which are quite sufficient to copy the experimental data. In addition, thermodynamic parameters (ΔG°, ΔH°, and ΔS°) for the studying complexes were calculated according to the values of stability constant (KST) at 25 °C obtained from the temperature dependence of stability constant by using van’t Hoff equation.

An infrared study of interactions in the system sodium tert-butoxide-tetrahydrofuran

1989 ◽  
Vol 54 (2) ◽  
pp. 308-315
Author(s):  
Libor Matějka ◽  
Lubomír Lochmann ◽  
Pavel Schmidt
Keyword(s):  
Stability Constant ◽  
Infrared Spectra ◽  
Adduct Formation ◽  
Large Excess ◽  
Infrared Study ◽  
Hydrocarbon Solvents ◽  
The Stability ◽  
System Sodium

The adduct of sodium tert-butoxide (t-BuONa) with tetrahydrofuran (THF) was studied by measuring changes of infrared spectra in the range 900-1100 cm-1. Alkoxide autoassociation and solvation of this associate by tetrahydrofuran play a role in adduct formation. In hydrocarbon solvents in the presence of minor amounts of THF, higher t-BuONa associates are dissociated, the preffered form being a tetramer solvated by three THF molecules. At large excess of THF, the tetramer is solvated by four THF molecules. The stability constant of the adduct, referred to one Na-O bond, is 5.01.

Metallo-β-cyclodextrins of 6A-(2-(2-(2-Aminoethylamino)-ethylamino)ethylamino)-6A-deoxy-β-cyclodextrin and 6A-Deoxy-6A-(1,4,7,10-tetraazacyclododecan-1-yl)-β-cyclodextrin: Their Formation and Complexation of (R)- and (S)-Tryptophan and Tryptophanate in Aqueous Solution

2000 ◽  
Vol 53 (5) ◽  
pp. 375 ◽  
Author(s):  
Suzanna D. Kean ◽  
Christopher J. Easton ◽  
Stephen F. Lincoln
Keyword(s):  
Aqueous Solution ◽  
Stability Constant ◽  
Binary Complexes ◽  
The Stability

The binary metallo-β-cyclodextrins formed by 6A-(2-(2-(2-aminoethylamino)ethylamino)ethylamino)-6A-deoxy-β-cyclodextrin, [M(βCDtrien)]2+, where M2+ = Ni2+, Cu2+ and Zn2+, are characterized by log(K/dm3 mol-1) = 11.500.02, 10.700.07 and 9.400.01, respectively, in aqueous solution at 298.2 K and I = 0.1 mol dm-3 (NaClO4), where K is the stability constant. For those formed by 6A-deoxy-6A-(1,4,7,10-tetraazacyclododecan-1-yl)-β-cyclodextrin, [M(βCDcyclen)]2+, where M2+ = Cu2+ and Zn2+, log(K/dm3 mol-1) = 13.610.02 and 11.620.04, respectively. The ternary metallo-β-cyclodextrins formed by [M(βCDtrien)]2+ and (R)- and (S)-tryptophanate, [M(βCDtrien)((R)-Trp)]+ and [M(βCDtrien)((S)-Trp)]+ are characterized by log(K/dm3 mol-1) = 6.900.04 and 6.790.04, 8.20.3 and 7.90.2, and 6.640.08 and 7.010.07, respectively, where M2+ = Ni2+, Cu2+ and Zn2+. For the ternary metallo-β-cyclodextrins formed by [M(βCDcyclen)]2+ and (R)- and (S)-tryptophanate, [M(βCDcyclen)((R)-Trp)]+ and [M(βCDcyclen)((S)-Trp)]+, log(K/dm3 mol-1) = 6.840.06 and 6.850.06, and 4.950.05 and 4.940.04, respectively, where M2+ = Cu2+ and Zn2+. Other binary and ternary metallo-β-cyclo-dextrins are also formed. Binary complexes formed by the substituted β-cyclodextrins are exemplified by βCDcyclen.(R)-Trp- and βCDcyclen.(S)-Trp- for which log(Kd/m3 mol-1) = 3.690.04 and 3.950.03, respectively. These data are discussed together with those from the literature characterizing other metallo-β-cyclodextrin and substituted β-cyclodextrin systems.

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