Thio derivatives of β-diketones and their metal chelates. XI. Stability constants of nicke(II), copper(II). zinc(II), cadniium(II), and lead(II) chelates of two monothio-β-diketones

1969 ◽  
Vol 22 (7) ◽  
pp. 1363 ◽  
Author(s):  
SE Livingstone ◽  
EA Sullivan
Keyword(s):  
Stability Constants ◽  
Water Solution ◽  
Supporting Electrolyte ◽  
Nickel Complexes ◽  
Metal Chelates ◽  
Acid Dissociation ◽  
Acid Dissociation Constant ◽  
Chloro Complexes ◽  
Lead And Cadmium ◽  
Derivatives Of

The acid dissociation constant (pKD) of the monothio derivative of benzoyl-acetone, viz. 3-mercapto-1-phenylbut-2-en-1-one (I), was found to be 10.43 in 74.5 vol. % dioxan-water solution. Stoicheiometric stability constants (log kn) of five metal chelates of (I) and of the monothio derivative of dibenzoylmethane, viz. 3-mercapto-1,3- diphenylprop-2-en-1-one (II), have been measured in 74.5 vol. % dioxan- water solution with both chloride and perchlorate as supporting electrolyte. ��� With chloride as supporting electrolyte the values obtained for log kav are as follows: with ligand (I), copper(II) 10.11, nickel(II) 9.25, zinc(II) 6.68, lead(II) 6.06, cadmium(II) 6.12; with ligand (II), copper(II) 10.66, nickel(II) 10.20, zinc(II) 7.44, lead(II) 7.11, cadmium(II) 6.90. With perchlorate as supporting electrolyte zinc, lead, and cadmium give values of log kav which are 1.5-1.9 units greater. The thermodynamic stability constants (logKn) were calculated from the stoicheiometric constants by use of the equations ���������� Log K1 = logk1 + 2.30������� logK2 = log k2 + 1.15 For the copper and nickel complexes of both (1) and (II) log Kav is greater than pKD; such a situation has been reported in only a few instances. ��� From the data obtained with chloride as a supporting medium, approximate stoicheiometric stability constants were calculated for the chloro complexes MCl+ (M = Zn, Cd, Pb) in 74.5 vol. % dioxan. The values obtained were: ZnCl+, 5.0; CdCl+, 5.7; PbCl+, 5.0.

Thio derivatives of β-diketones and their metal chelates. V. Acid dissociation constants of some Monothio-β-diektones and stability constants of anickel(II) and a copper(II) chelate

1966 ◽  
Vol 19 (11) ◽  
pp. 2035 ◽  
Author(s):  
SHH Chaston ◽  
SE Livingstone
Keyword(s):  
Stability Constants ◽  
Mole Fraction ◽  
Dissociation Constants ◽  
Metal Chelates ◽  
Acid Dissociation ◽  
Acid Dissociation Constants ◽  
Water Solutions ◽  
Acetyl Acetone ◽  
The Stability ◽  
Derivatives Of

The acid dissociation constants (PKD) of the monothio derivatives of acetyl-acetone, dibenzoylmethane, and 3,3,3-trifluoro-1-(2- thenoyl)acetone, viz. 4-mercap-topent-3-en-2-one (I), 3-mercapto-1,3- diphenylprop-2-en-1-one (II), and 1,1,1-trifluoro-4-mercapto-4-(2- thienyl)but-3-en-2-one (III), were determined in dioxan/water solutions with varying mole fraction (n2) of dioxan. Over a range of n2 from 0.18 to 0.44 the values of pKD were found to vary linearly with n2 as given by the equations: (I) pKD = 5.7+12.0n2; (II) pKD = 7.0+10.9n2; (III) pKD = 3.55 + 9.2n2. The thio derivatives (I), (II), and (III) have pKD values 2.0-2.7 log units lower than their oxygen analogues. The logarithm of the stability constants (log β2) for the nickel(II) and copper(II) complexes of (II) were found to be 21.7 and 22.2, respectively. For both complexes K2 > K1. Comparison with the stability constants of the dibenzoylmethane complexes shows that for nickel(II) the complex of the monothio-β-diketone is more stable than that of the β-diketone while the converse is true for copper(II).

Thio derivatives of β-diketones and their metal chelates. IX. Nickel and copper complexes of some new fluorinated monothio-β-diketones

1968 ◽  
Vol 21 (7) ◽  
pp. 1781 ◽  
Author(s):  
RKY Ho ◽  
SE Livingstone
Keyword(s):  
General Formula ◽  
High Spin ◽  
Copper Complexes ◽  
Nickel Complexes ◽  
Metal Chelates ◽  
Sulphur Atom ◽  
Derivatives Of ◽  
Infrared Data

Four new fluorinated monothio-β-diketones of general formula RC(SH)=CH- COCF3 have been prepared; they are: l,l,l-trifluoro-4-mercapto-4-(4-methylphenyl)but-3-en-2-one (R = p-methylphenyl), 1,1,1-trifluoro-4-mercapto-4- (4-methoxyphenyl)but-3-en-2-one (R = p-methoxyphenyl), 4-(4-bromophenyl)-l,l,l- trifluoro-4-mercaptobut-3-en-2-one (R = p-bromophenyl), and l,l,l-trifluoro-4- (2-furyl)-4-mercaptobut-3-en-2-one (R = 2-furyl). Their nickel complexes, which are brown and diamagnetic, yield stable high-spin bis-pyridine adducts. When R = p-MeC6H4, p-MeOC6H4, or p-BrC6H4 the ligand yields both copper(1) and copper(11) complexes but when R = 2-furyl only a copper(11) complex is obtained. Infrared data indicate that in the copper(1) complexes the ligand is coordinated through the sulphur atom only.

scholarly journals A Reversed-phase HPLC Study of the Complexation of Benzene Derivatives Guest Molecules with 5,17-bis(N-Tolyliminomethyl)-25,27-dipropoxycalix[4]arene in Acetonitrile–Water Solution

1999 ◽  
Vol 23 (1) ◽  
pp. 60-61
Author(s):  
O. I. Kalchenko ◽  
A. V. Solovyov ◽  
J. Lipkowski ◽  
V. I. Kalchenko
Keyword(s):  
Stability Constants ◽  
Water Solution ◽  
Reversed Phase ◽  
Benzene Derivatives ◽  
Reversed Phase Hplc ◽  
Guest Molecules ◽  
Hplc Study

Stability constants of the host–guest complexes of 5,17-bis( N-tolyliminomethyl)-25,27-dipropoxycalix[4]arene with benzene derivatives were determined by reversed-phase HPLC in acetonitrile–water solution.

Accurate acid dissociation constant (pKa) calculation for the sulfachloropyridazine and similar molecules

2021 ◽  
Vol 27 (8) ◽  
Author(s):  
Fernando Marques Carvalho ◽  
Yuri Alves de Oliveira Só ◽  
Alessandra Sofia Kiametis Wernik ◽  
Mônica de Abreu Silva ◽  
Ricardo Gargano
Keyword(s):  
Dissociation Constant ◽  
Acid Dissociation ◽  
Acid Dissociation Constant ◽  
Pka Calculation

Dissociation of imino proton(s) of a highly water-soluble metal-free phthalocyanine and determination of its pKa value in water

2013 ◽  
Vol 17 (06n07) ◽  
pp. 447-453 ◽  
Author(s):  
Hiroaki Isago ◽  
Harumi Fujita
Keyword(s):  
Aqueous Media ◽  
Thermal Reaction ◽  
Water Soluble ◽  
Acid Dissociation ◽  
Acid Dissociation Constant ◽  
Metal Free ◽  
Imino Proton ◽  
Pka Value ◽  
Triton X

Dissociation of imino proton(s) in the cavity of the macrocycle of a highly water-soluble, metal-free phthalocyanine ( H 2( H 4 tsppc ); where H 4 tsppc denotes tetrakis{(2′,6′-dimethyl-4′-sulfonic acid)phenoxy}phthalocyaninate) in ethanolic and aqueous solutions has spectrophotometrically been investigated. The spectral changes associated with reaction with NaOH have been found to involve one-proton transfer process in aqueous media while two-protons process in ethanolic media. The acid-dissociation constant of the first imino proton in water (in the presence of Triton X-100) has been determined to be 12.5 ± 0.2 (as pKa) at 25 °C. The doubly deprotonated species in EtOH has been easily converted to its corresponding cobalt(II) derivative by thermal reaction with anhydrous CoCl 2.

Thio derivatives of β-diketones and their metal chelates. XIX. Metal chelates of two new fluorinated Monothio-β-diketones and their mass spectra

1975 ◽  
Vol 28 (6) ◽  
pp. 1249 ◽  
Author(s):  
SE Livingstone ◽  
N Saha
Keyword(s):  
Mass Spectra ◽  
Metal Chelates ◽  
The Novel ◽  
Copper Chelates ◽  
Derivatives Of

The nickel(II), palladium(II), platinum(II), copper(II), zinc(II) and rhodium(III) chelates of the new fluorinated monothio-β-diketones RC(SH)=CHCOCF3 (R = Pri, Bui) and the iron(III), ruthenium(III) and cobalt(III) chelates of PriC(SH)=CHCOCF3 have been prepared. The mass spectra of all but the two copper chelates have been obtained. The novel features of the spectra are the occurrence of the ions M-(R-H), M-R, and M-LH and the loss of H2S from the ions M-LH and M-L.

scholarly journals Stability Studies of Transition Metal Chelates of 5-Bromosalicylidene-4-methoxyaniline andSalicylidene-2,3-dimethylaniline as Ligands

2011 ◽  
Vol 8 (4) ◽  
pp. 1911-1915
Author(s):  
N. G. Nadkarni ◽  
K. V. Mangaonkar
Keyword(s):  
Ionic Strength ◽  
Transition Metal ◽  
Stability Constants ◽  
Metal Chelates ◽  
Ternary Complexes ◽  
Water Medium ◽  
Stability Studies ◽  
Binary And Ternary Complexes ◽  
Transition Metal Chelates ◽  
The Stability

Binary and ternary complexes of the type M-Y and M-X-Y [M = Mn(II), Ni(II), Cu(II) and Zn(II); X = 5-bromosalicylidene-4-methoxyaniline and Y = salicylidene-2,3-dimethylaniline] have been examined pH-metrically at 27±0.5°C and at constant ionic strength, μ = 0.1 M (KCl) in 75 : 25(v/v) 1,4-dioxne-water medium. The stability constants for binary (M-Y) and ternary (M-X-Y) systems were calculated.

Interference by Tin in AOAC Dry-Ash Voltammetric Method for Determination of Lead and Cadmium in Canned Foods

1988 ◽  
Vol 71 (4) ◽  
pp. 857-859
Author(s):  
Walter Holak ◽  
John J Specchio
Keyword(s):  
Tartaric Acid ◽  
False Positive ◽  
Supporting Electrolyte ◽  
Canned Food ◽  
Voltammetric Method ◽  
Lead And Cadmium ◽  
Anodic Stripping ◽  
Canned Foods ◽  
Positive Results

Abstract When lead and cadmium were determined in samples of canned food by the AOAC anodic stripping voltammetric method, an interference was observed which was believed to be tin(IV). This interference could cause false positive results for lead and cadmium. The electroactivity of tin(IV) was suppressed by increasing the concentration of tartaric acid in the supporting electrolyte from 0.005M to 0.1M after mixing with an equal volume of sample solution.

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