Relation between stability constants of metal ion cryptates in two solvents and the transfer activity coefficients of the metal ions

1985 ◽  
Vol 14 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Miran K. Chantooni ◽  
Izaak M. Kolthoff
Keyword(s):  
Metal Ions ◽  
Stability Constants ◽  
Activity Coefficients ◽  
Metal Ion ◽  
Transfer Activity

scholarly journals Comparative study of binding strengths of heavy metals with humic acid

2013 ◽  
Vol 67 (5) ◽  
pp. 773-779 ◽  
Author(s):  
Ivana Kostic ◽  
Tatjana Andjelkovic ◽  
Ruzica Nikolic ◽  
Tatjana Cvetkovic ◽  
Dusica Pavlovic ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Humic Acid ◽  
Metal Ions ◽  
Stability Constants ◽  
Metal Ion ◽  
Heavy Metal Ions ◽  
Exchange Method ◽  
Divalent Metal Ion ◽  
The Stability

The complexation of humic acid with certain heavy metal ions (Co(II), Ni(II), Cu(II), Zn(II) and Pb(II)) was investigated. The stability constants of humate complexes were determined by method which is based on distribution of metal ions between solution and resin in the presence and the absence of ligand, known as Schubert?s ion exchange method. Experiments were performed at 25 ?C, at pH 4.0 and ionic strength of 0.01 mol dm-3. It was found that the 1:1 complexes were formed between metal ions and humic acid. Obtained results of the stability constants, log ?mn, of complexes formed between the metal ions and humic acid follow the order Co(II) < Ni(II) < Cu(II) > Zn(II) which is the same like in the Irving-Williams series for the binding strength of divalent metal ion complexes. Stability constant of complex between Pb(II) ions and humic acid is greater than stability constants of other investigated metal-humate complexes. The investigation of interaction between heavy metal ions and humics is important for the prediction of the distribution and control of the migration of heavy metals in natural environment.

Transfer activity coefficients between some dipolar aprotic solvents and alcohols of salts composed of various anions and potassium complexed with Bis(4,4'(5')-t-butylbenzo)-18-crown-6

1983 ◽  
Vol 36 (9) ◽  
pp. 1753 ◽  
Author(s):  
Jr MK Chantooni ◽  
IM Kolthoff ◽  
G Roland
Keyword(s):  
Dimethyl Sulfoxide ◽  
Stability Constants ◽  
Propylene Carbonate ◽  
Activity Coefficients ◽  
Isopropyl Alcohol ◽  
The Other ◽  
Aprotic Solvents ◽  
Transfer Activity ◽  
Dipolar Aprotic Solvents

Stability constants, Kf(LK+) and Kf(LKX) = [LKX]/[L][KX] at 25� in the dipolar aprotic solvents acetone (Me2CO), acetonitrile (MeCN), propylene carbonate (pc), N,N-dimethylformamide (HCONMe2), dimethyl sulfoxide (Me2SO), as well as in the alcohols, methanol (MeOH), isopropyl alcohol (Pr1OH), and butan -1-ol (BuOH) have been determined, L being bis(4,4'(5')-t-buty1benzo)-18- crown-6 (di(BuBo)-18-cr-6). This crown is considerably more lipophylic than is dibenzo-18-crown-6. Values of Kf(LKX) have been found from values of Kf(LK+), KA(KX) and KA(LKX). Transfer activity coefficients, Me2COγS, have been calculated (based on the Parker proposal that γ(Ph4As+) = γ(BPh4-) between acetone and the various solvents used of K+, Br-, ClO4-, P1- (picrate), LK+, KX, and LKX. It is found that K+ is more strongly solvated in Me2CO than in the other aprotic solvents of low donicity. The reverse is true between Me2CO and HCONMe2 or Me2SO (even after correcting for the Born effect).

Stabilities in Water and Transfer Activity Coefficients between Nonaqueous Solvents and Water of 1 : 1 Complexes of 15,15-Dimethyl-16-crown-5 with Metal Ions

2001 ◽  
Vol 74 (2) ◽  
pp. 311-315 ◽  
Author(s):  
Shoichi Katsuta ◽  
Takako Motoyama ◽  
Yasuyuki Takeda ◽  
Mikio Ouchi
Keyword(s):  
Metal Ions ◽  
Activity Coefficients ◽  
Nonaqueous Solvents ◽  
Transfer Activity

Stabilities and Transfer Activity Coefficients from Water to Polar Nonaqueous Solvents of Benzo-15-Crown-5- and 15-Crown-5-Alkali Metal Ion Complexes

2002 ◽  
Vol 55 (4) ◽  
pp. 459-468 ◽  
Author(s):  
Yasuyuki Takeda ◽  
Munehiro Tanaka ◽  
Hiroaki Yamada ◽  
Shoichi Katsuta
Keyword(s):  
Alkali Metal ◽  
Activity Coefficients ◽  
Metal Ion ◽  
Nonaqueous Solvents ◽  
Metal Ion Complexes ◽  
Alkali Metal Ion ◽  
Transfer Activity

scholarly journals Stabilities in Water and Transfer Activity Coefficients from Water to Nonaqueous Solvents of Benzo-18-crown-6–Metal Ion Complexes

1989 ◽  
Vol 62 (4) ◽  
pp. 999-1003 ◽  
Author(s):  
Yasuyuki Takeda ◽  
Rie Kohno ◽  
Yoshihiro Kudo ◽  
Naoaki Fukada
Keyword(s):  
Activity Coefficients ◽  
Metal Ion ◽  
Nonaqueous Solvents ◽  
Metal Ion Complexes ◽  
Transfer Activity

The stability constants of ethylenediphosphinetetraacetate complexes

1982 ◽  
Vol 47 (4) ◽  
pp. 1078-1085 ◽  
Author(s):  
Jana Podlahová ◽  
Jaroslav Podlaha
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Stability Constants ◽  
Metal Ion ◽  
Computer Programs ◽  
Data Treatment ◽  
Relative Affinity ◽  
Stability Constants Of Complexes ◽  
Soft Metal ◽  
The Stability

The stability constants of complexes formed by the anions of ethylenediphosphinetetraacetic acid and the metal ions Cu(I), Ag(I), Ca(II), Mn(II), Fe(II), Co(II), Ni(II), Zn(II), Cd(II), Hg(II), Pb(II) and La(III) were determined by various methods (mainly potentiometry and UV-VIS spectrophotometry), followed by data treatment using standard computer programs. The type and stability of the complexes formed depend mostly on the relative affinity of the particular metal ion for the two donor groups of the ligand. Unlike EDTA, the ligand is highly selective for soft metal ions, whose complexes are very stable even in strongly acidic aqueous solutions.

scholarly journals Stability constants of complexes of metal ions with peatsoil humic acids under non-acid-conditions

2021 ◽  
Vol 14 (1) ◽  
pp. 54-63
Author(s):  
Yusuf Sabo ◽  
W.L.O. Jimoh ◽  
Isa Baba Koki ◽  
Q.O. Sholadoye
Keyword(s):  
Metal Ions ◽  
Stability Constants ◽  
Humic Acids ◽  
Metal Ion ◽  
Aqueous Media ◽  
Computational Method ◽  
Divalent Metal Ions ◽  
Acid Condition ◽  
Stability Constants Of Complexes ◽  
The Stability

Stability constants of complexes of four divalent metal ions viz. Cu2+, Pb2+,Mg2+ and Cd2+  with humic acids (HA) were determined by potentiometric titration of humic acids with the corresponding salt of the divalent metals in aqueous media under non-acid-condition. The log K (logarithm of the stability constant) ranged from 1.0942 to 2.7471 for metal-humic acid complexes were determined using point-wise computational method. The order of stability constants were obtained as follows: Cu >Pb> Cd > Mg for metal -HA complexes respectively, indicating a higher degree of complexation with Cu metal ion. 

scholarly journals Coordination properties of N,O-carboxymethyl chitosan (NOCC). Synthesis and equilibrium studies of some metal ion complexes. Ternary complexes involving Cu(II) with (NOCC) and some biorelevant ligand

2012 ◽  
Vol 10 (1) ◽  
pp. 59-70 ◽  
Author(s):  
Azza Shoukry ◽  
Wafaa Hosny
Keyword(s):  
Metal Ions ◽  
Stability Constants ◽  
Metal Ion ◽  
Ternary Complexes ◽  
Central Metal ◽  
Magnetic Studies ◽  
Complex Formation Equilibria ◽  
Equilibrium Studies ◽  
The Stability ◽  
Solid Complexes

AbstractIn the present study, the acid-base equilibria of N,O-carboxymethy chitosan abbreviated as (NOCC), is investigated. The complex formation equilibria with the metal ions Cu(II), Ni(II), Co(II), Mn(II), and Zn(II) are investigated potentiometrically. The stability constant values of the binary and ternary complexes formed in solution were determined and the binding centers of the ligands were assigned. The relationships between the properties of the studied central metal ions as ionic radius, electronegativity, atomic number, and ionization potential, and the stability constants of the formed complexes were investigated in an effort to give information about the nature of chemical bonding in complexes and make possible the calculation of unknown stability constants. Cu(II), Ni(II), and U(VI) complexes with NOCC are isolated as solid complexes and characterized by conventional chemical and physical methods. The structures of the isolated solid complexes are proposed on the basis of the spectral and magnetic studies. The ternary copper(II) complexes involving NOCC and various biologically relevant ligands containing different functional groups, as amino acids and DNA constituents are investigated. The stability constants of the complexes are determined and the concentration distribution diagrams of the complexes are evaluated.

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