Sulphur-nitrogen chelating agents. VI. Five- and six-coordinate complexes of 3d metal ions with an SNN tridentate ligand

1969 ◽  
Vol 22 (8) ◽  
pp. 1613 ◽  
Author(s):  
PSK Chia ◽  
SE Livinhstone
Keyword(s):  
Metal Ions ◽  
High Spin ◽  
Infrared Spectra ◽  
Magnetic Moment ◽  
Nickel Complex ◽  
Copper Complexes ◽  
Chelating Agents ◽  
Iron Complex ◽  
Tridentate Ligand ◽  
Infrared Data

Mono-ligand complexes of 6-methylpyrid-2-yl-N-(2?-methylthiophenyl)- methyleneimine (SNSMe) of the type MX2(SNNMe) (M = Mn, Fe, Co, Xi, and Cu; X = Cl, Br, I, or NCS) have been prepared. Infrared data show that in all the complexes the ligand (SNNMe) is tridentate. The electronic and infrared spectra indicate that the complexes of manganese, iron, and cobalt are five-coordinate, whereas the nickel and copper complexes are six-coordinate and polymeric. The complex CO(NO3)2(SNNMe) is six- coordinate and contains one bidentate and one unidentate nitrato group. ��� The bis-ligand complexes [N(SNNMe)2]Y2 (M = Fe, Ni, and Cu; Y = ClO4 or BF4) were also isolated. The iron complex is low-spin (μ 1.5 B.M.) but the magnetic moment of the nickel complex (μ 3.0 B.M.) is normal for high-spin octahedral nickel(II).

Sulphur-nitrogen chelating agents. VII. Five- and six-coordinate complexes of cobalt(II), nickel(II), and copper(II) with an S-N-S tridentate ligand

1969 ◽  
Vol 22 (9) ◽  
pp. 1817 ◽  
Author(s):  
SE Livingstone ◽  
JD Nolan
Keyword(s):  
High Spin ◽  
Electronic Spectra ◽  
Copper Complexes ◽  
Chelating Agents ◽  
Nickel Complexes ◽  
Tridentate Ligand ◽  
Octahedral Complex ◽  
Halide Complexes

Mono-ligand complexes of the tridentate ligand N-(2-methylthiophenyl)- 2?-methylthiophenylmethyleneimine (SNS) of the type MX2(SNS) (M = Co, Ni, Cu; X = Cl, Br, I, or FCS) have been prepared. The electronic spectra indicate that the cobalt halide complexes are five-coordinate, whereas the complex Co(NCS)2- (SNS) and the nickel complexes are six- coordinate and polymeric. The copper complexes CuX2(SNS) (X = Cl, Br) are possibly five-coordinate. ��� The bis-complexes of nickel [Ni(SNS)2]X2 (X = ClO4, BF4) are high- spin but the complex [Co(SNS)2](ClO4)2 appears to be a rare example of a low-spin octahedral complex of cobalt(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.

Multidentate chelating agents from Quinoline-8-aldehyde. I. Tridentate and quadridentate Schiff bases from primary diamines

1966 ◽  
Vol 19 (12) ◽  
pp. 2241 ◽  
Author(s):  
J Dekkers ◽  
HA Goodwin
Keyword(s):  
Schiff Base ◽  
Metal Ions ◽  
Schiff Bases ◽  
Copper Complexes ◽  
Chelating Agents ◽  
Steric Effects ◽  
Partial Hydrolysis ◽  
Trigonal Bipyramidal ◽  
Hydrolysis Of

Complexes of 1,2-bis(8-quinolylmethyleneimino)ethane with cobalt(II), nickel(II), and copper(II) are described. The copper complexes are five-covalent and, it is suggested, trigonal bipyramidal. Reaction of the Schiff base with iron(II), cobalt(III), and, under certain conditions, nickel(II) leads to its partial hydrolysis, and complexes of the tridentate 1-amino-2-(8-quinolylmethyleneimino)ethane are obtained. The hydrolysis of the Schiff base in the presence of metal ions is discussed in terms of steric effects within the base and of the stereochemical demands of the metal ions. Complexes of 1,2-bis(8-quinolylmethyleneimino)benzene and its hydrolysis derivative 1-amino-2-(8-quinolylmethyleneimino)ethane are also described.

Metal complexes of sulfur–nitrogen chelating agents. V. 2-N-Ethylaminocyclopentene-1-dithiocarboxylic acid complexes of Ni(II), Pd(II), Pt(II), Co(II), Co(III), and Cu(I)

1976 ◽  
Vol 54 (17) ◽  
pp. 2827-2831 ◽  
Author(s):  
K. Nag ◽  
D. S. Joardar
Keyword(s):  
Thermal Analysis ◽  
Metal Ions ◽  
Metal Complexes ◽  
Magnetic Moment ◽  
Nmr Spectra ◽  
Chelating Agents ◽  
Metal Chelates ◽  
Ambidentate Ligand

2-N-Ethylaminocyclopentene-1-dithiocarboxylic acid (EACDA) acts as an ambidentate ligand toward several metal ions. Bis-chelates have been obtained with Ni(II), Pd(II), Pt(II), and Co(II), and tris-chelate with Co(III). Cu(I) forms a 1:1 complex. The bonding sites involved in the metal chelates and their stereochemistry have been ascertained from electronic, infrared and nmr spectra, magnetic moment, and thermal analysis. In the Co(II) and Co(III) chelates bonding takes place from (S,S−) donor sites, whereas in the Ni(II), Pd(II), and Pt(II) chelates (N,S−) type bonding occurs. The Cu(I) complex appears to be polymeric in nature.

Evidence from infrared spectra for the magnetic moment directions of CR cations in the spinel ferrites

2015 ◽  
Vol 463 ◽  
pp. 26-29 ◽  
Author(s):  
G.D. Tang ◽  
Z.F. Shang ◽  
X.Y. Zhang ◽  
J. Xu ◽  
Z.Z. Li ◽  
...  
Keyword(s):  
Infrared Spectra ◽  
Magnetic Moment ◽  
Spinel Ferrites

Study on desorption of Mn, Fe, and Mg from TMP and evaluation of the complexing strength of different chelating agents using side reaction coefficients 10th EWLP, Stockholm, Sweden, August 25–28, 2008

Holzforschung ◽  
2009 ◽  
Vol 63 (6) ◽  
Author(s):  
Kim Granholm ◽  
Pingping Su ◽  
Leo Harju ◽  
Ari Ivaska
Keyword(s):  
Citric Acid ◽  
Metal Ions ◽  
Chelating Agents ◽  
Side Reaction ◽  
Sodium Dithionite ◽  
Thermomechanical Pulp ◽  
Peroxide Bleaching ◽  
Ph Values ◽  
Reducing Environment ◽  
Ph Range

Abstract Chelation of thermomechanical pulp (TMP) was studied in this work. The desorption of Mn, Fe, and Mg due to their impact on peroxide bleaching was investigated. The desorption experiments were performed with EDTA, citric acid, oxalic acid, and formic acid as chelating agents at different pH. Chelation experiments with EDTA were carried out at pH 3–11. Sodium dithionite was used as the reducing agent in studying chelation with EDTA in a reducing environment. Mn was very effectively desorbed with EDTA from TMP at pH <10 and the reducing environment further improved the removal of all the studied metal ions from TMP with EDTA. Citric acid also removed Mn effectively from TMP at pH 5. The thermodynamic stability constants of different metal chelates do not present the correct picture of how strongly the metal ions are bound by the chelating agents in different conditions. But by means of the side reaction coefficients (α M(L)-coefficients) it is also theoretically possible to evaluate and compare the real binding strengths between the metal ions and different chelating agents at varying pH values and other solution conditions. In this study, a theory is given for the calculation of side reaction coefficients. Values of the α M(L)-coefficients, for the pH range 0–14, are presented for EDTA, DTPA, and also for some other new potential environmentally friendly chelating agents.

Hydrogen bonding and conformation in cis- and trans-2-alkoxy-3-hydroxytetrahydrofurans

1968 ◽  
Vol 46 (1) ◽  
pp. 21-24 ◽  
Author(s):  
W. W. Zajac Jr. ◽  
F. Sweet ◽  
R. K. Brown
Keyword(s):  
Hydrogen Bonding ◽  
Infrared Spectra ◽  
Hydroxyl Absorption ◽  
Cis And Trans ◽  
In Cis ◽  
Infrared Data ◽  
Hydrogen Bonded

Infrared spectra show both free and hydrogen bonded hydroxyl absorption in several trans-2-alkoxy-3-hydroxytetrahydrofurans. The extent of non-bonded hydroxyl is greater than that of bonded hydroxyl. Suggestions are made of possible conformations which might account for the infrared data.

Competition between Cd(II) and other divalent transition metal ions during complex formation with amino acids, peptides, and chelating agents

2016 ◽  
Vol 327-328 ◽  
pp. 55-69 ◽  
Author(s):  
Maurizio Remelli ◽  
Valeria M. Nurchi ◽  
Joanna I. Lachowicz ◽  
Serenella Medici ◽  
M. Antonietta Zoroddu ◽  
...  
Keyword(s):  
Amino Acids ◽  
Complex Formation ◽  
Transition Metal ◽  
Metal Ions ◽  
Chelating Agents ◽  
Transition Metal Ions
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