Nitrogenous chelate complexes of transition metals. VII. Complexes of silver(I) and silver(II) with tridentate chelating ligands

1970 ◽  
Vol 23 (6) ◽  
pp. 1125 ◽  
Author(s):  
CM Harris ◽  
TN Lockyer
Keyword(s):  
Aqueous Solution ◽  
Schiff Base ◽  
Absorption Band ◽  
Magnetic Moments ◽  
Chelating Ligands ◽  
Chelate Complexes ◽  
Complex Ions ◽  
Strong Absorption Band ◽  
Stable Species ◽  
Complexes Of Transition Metals

Silver(1) complexes of 2,2',2"-terpyridine and a related Schiff base chelate 8-(or-pyridylmethyleneamino)quinoline have been prepared. They are of the type Ag(chelate)X, where X = NO3, ClO4, and PF6. Both Ag(terpy)+ and Ag(pmq)+ are stable in solution and conductance measurements have been obtained. Ag(terpy)PF6 is monomeric in nitrobenzene. Reaction of the above complex ions with pyridine or triphenylphosphine affords stable species of the form [Ag(chelate)(py)]+ and [Ag(chelate)(Ph3P)]+ which have been isolated as their perchlorate salts. Both Ag(chelate)+ and [Ag(ohelate)L]+ involve unusual stereochemistry for AgI. The known paramagnetic AgII complexes Ag(terpy)X2 (X = NO3, ClO4, �S2O8) have been reprepared. They are unstable in solution and reduce readily to AgI. They all show magnetic moments in the range 1.7-1.9 B.M. Ag(terpy)2+ in an aqueous solution of CeIv shows a strong absorption band at 470 mμ (880).

Nitrogenous chelate complexes of transition metals. VI. Complexes of copper(II) with 2,2',2'-terpyridine

1970 ◽  
Vol 23 (4) ◽  
pp. 673 ◽  
Author(s):  
CM Harris ◽  
TN Lockyer
Keyword(s):  
Aqueous Solution ◽  
Transition Metals ◽  
Water Molecule ◽  
General Type ◽  
Aqueous Media ◽  
Chelate Complexes ◽  
Excess Copper ◽  
Complexes Of Transition Metals ◽  
Amine Ligands

A series of compounds of the general type Cu(terpy)X2 (terpy = 2,2',2"- terpyridine; X = Cl, Br, I, NCS) have been prepared. The above complexes are sparingly soluble in non-aqueous media in which they show some ionization to yield species of the kind [Cu(terpy)X]+ which are isolable as their perchlorate salts. Reaction of terpyridine with excess copper(11) perchlorate yields [Cu(terpy)-(HzO)](ClO4)2. The water molecule can be replaced by both mono- and bi-dentate amine ligands giving the complexes Cu(terpy)L](ClO4)2 (L = NH3, py, bipy). Conductimetric titrations in non-aqueous solvents show that Cu(terpy)(H2O)]2+ reacts with halide ion to give, in turn, [Cu(terpy)X]+ and Cu(terpy)X2. The bis-terpyridine complexes [Cu(terpy)2]X2,nH2O (X = ClO4, n = 1; X = NCS, n = 2; X = I, n = 1) have also been prepared. [Cu(terpy)2]2+ is stable in the presence of halide ion in aqueous solution but in non-aqueous solution rearrangement to the corresponding mono-complex Cu(terpy)X2 is instantaneous. This was confirmed by conductimetric titrations. Reaction of terpyridine with excess copper(11) chloride affords a complex Cuz(terpy)Cl4, which is shown to be Cu(terpy)Cl][CuCl3].

Chelate complexes of molybdenum. I. Thiolo-bridged molybdenum(III) complexes with low magnetic moments

1965 ◽  
Vol 18 (10) ◽  
pp. 1549 ◽  
Author(s):  
LF Lindoy ◽  
SE Livingstone ◽  
TN Lockyer
Keyword(s):  
Magnetic Moment ◽  
Magnetic Moments ◽  
Thiol Group ◽  
Molybdenum Atom ◽  
Chelating Ligands ◽  
Chelate Complexes ◽  
Metal Interaction ◽  
Metal Metal ◽  
Multinuclear Complexes ◽  
Bridging Groups

Thiolo-bridged complexes of molybdenum(III) have been obtained from the reaction in alcohol of lithium hexachloromolybdate(III) enneahydrate with a number of chelating ligands containing a thiol group. These multinuclear complexes have three bridging groups--either three thiolo-bridges or two thiolo-bridges and one chloro-bridge-linking the molybdenum atoms which, except in one complex, are probably eight-coordinate, Only two complexes were obtained from the reaction of the ligands with potassium hexabromomolybdate(III) in alcohol. The bromo-derivatives were similar to but less stable than their chloro-analogues. All the complexes have anomalously low magnetic moments ranging from 0.3 to 1.56 BAT. per molybdenum atom, owing to metal-metal interaction either directly or via the bridging atoms. A monomeric five-coordinate molybdenum(1v) complex MoO[(PriO)2PS2]2 with a low magnetic moment (μ 0.9 B.M.) is also described.

Schiff base equilibria. II. Beryllium complexes of N-n-butylsalicylideneimine and the hydrolysis of the Be2+ ion

1965 ◽  
Vol 18 (5) ◽  
pp. 651 ◽  
Author(s):  
RW Green ◽  
PW Alexander
Keyword(s):  
Aqueous Solution ◽  
Schiff Base ◽  
Complex Formation ◽  
Distribution Coefficient ◽  
Dilute Aqueous Solution ◽  
The Stability ◽  
Ph Range ◽  
Hydrolysis Of ◽  
Beryllium Complexes ◽  
Equilibria In Aqueous Solution

The Schiff base, N-n-butylsalicylideneimine, extracts more than 99.8% beryllium into toluene from dilute aqueous solution. The distribution of beryllium has been studied in the pH range 5-13 and is discussed in terms of the several complex equilibria in aqueous solution. The stability constants of the complexes formed between beryllium and the Schiff base are log β1 11.1 and log β2 20.4, and the distribution coefficient of the bis complex is 550. Over most of the pH range, hydrolysis of the Be2+ ion competes with complex formation and provides a means of measuring the hydrolysis constants. They are for the reactions: Be(H2O)42+ ↔ 2H+ + Be(H2O)2(OH)2, log*β2 - 13.65; Be(H2O)42+ ↔ 3H+ + Be(H2O)(OH)3-, log*β3 -24.11.

Catalytic autooxidation of hydroquinone in the presence of chelate complexes of transition metals

1982 ◽  
Vol 21 (1-2) ◽  
pp. 41-44 ◽  
Author(s):  
M. E. Volpin ◽  
M. Jáky ◽  
E. M. Kolosova ◽  
M. Yu. Tuvin ◽  
G. N. Novodarova
Keyword(s):  
Transition Metals ◽  
Chelate Complexes ◽  
Complexes Of Transition Metals

scholarly journals Donor Atom Preference of Organoruthenium and Organorhodium Cations on the Interaction with Novel Ambidentate (N,N) and (O,O) Chelating Ligands in Aqueous Solution

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3586
Author(s):  
Sándor Nagy ◽  
András Ozsváth ◽  
Attila Cs. Bényei ◽  
Etelka Farkas ◽  
Péter Buglyó
Keyword(s):  
Aqueous Solution ◽  
Metal Ion ◽  
Platinum Group Metal ◽  
Molecular Structures ◽  
Chelating Ligands ◽  
Metal Ion Binding ◽  
Biologically Relevant ◽  
X Ray Crystallography ◽  
Ligand Ratio ◽  
Ph Range

Two novel, pyridinone-based chelating ligands containing separated (O,O) and (Namino,Nhet) chelating sets (Namino = secondary amine; Nhet = pyrrole N for H(L3) (1-(3-(((1H-pyrrole-2-yl)methyl)amino)propyl)-3-hydroxy-2-methylpyridin-4(1H)-one) or pyridine N for H(L5) (3-hydroxy-2-methyl-1-(3-((pyridin-2-ylmethyl)amino)propyl)pyridin-4(1H)-one)) were synthesized via reduction of the appropriate imines. Their proton dissociation processes were explored, and the molecular structures of two synthons were assessed by X-ray crystallography. These ambidentate chelating ligands are intended to develop Co(III)/PGM (PGM = platinum group metal) heterobimetallic multitargeted complexes with anticancer potential. To explore their metal ion binding ability, the interaction with Pd(II), [(η6-p-cym)Ru]2+ and [(η5-Cp*)Rh]2+ (p-cym = 1-methyl-4-isopropylbenzene, Cp* = pentamethyl-cyclopentadienyl anion) cations was studied in aqueous solution with the combined use of pH-potentiometry, NMR and HR ESI-MS. In general, organorhodium was found to form more labile complexes over ruthenium, while complexation of the (N,N) chelating set was slower than the processes of the pyridinone unit with (O,O) coordination. Formation of the organoruthenium complexes starts at lower pH (higher thermodynamic stabilities of the corresponding complexes) than for [(η5-Cp*)Rh]2+ but, due to the higher affinity of [η6-p-cym)Ru]2+ towards hydrolysis, the complexed ligands are capable of competing with hydroxide ion in a lesser extent than for the rhodium systems. As a result, under biologically relevant conditions, the rhodium binding effectivity of the ligands becomes comparable or even slightly higher than their effectivity towards ruthenium. Our results indicate that H(L3) is a less efficient (N,N) chelator for these metal ions than H(L5). Similarly, due to the relative effectivity of the (O,O) and (N,N) chelates at a 1:1 metal-ion-to-ligand ratio, H(L5) coordinates in a (N,N) manner to both cations in the whole pH range studied while, for H(L3), the complexation starts with (O,O) coordination. At a 2:1 metal-ion-to-ligand ratio, H(L3) cannot hinder the intensive hydrolysis of the second metal ion, although a small amount of 2:1 complex with [(η5-Cp*)Rh]2+ can also be detected.

scholarly journals 3-Hydroxy-2-naphthoate Complexes of Transition Metals with Hydrazine - Preparation, Spectroscopic and Thermal Studies

2009 ◽  
Vol 6 (s1) ◽  
pp. S413-S421 ◽  
Author(s):  
N. Arunadevi ◽  
S. Vairam
Keyword(s):  
Thermal Degradation ◽  
Magnetic Moments ◽  
Thermal Studies ◽  
Analytical Data ◽  
Transition Metal Ions ◽  
Naphthoic Acid ◽  
Complexes Of Transition Metals ◽  
Xrd Patterns ◽  
Dta Studies ◽  
Nano Size

Reaction of hydrazine and 3-hydroxy-2-naphthoic acid with some transition metal ions forms two types of complexes: (i) [M(N2H4){C10H6(3-O)(2-COO)(H2O)2] where M=Ni, Co, Cd and Zn, at pH 9 and (ii) [M(N2H5)2{C10H6(3-O)(2-COO)}2].xH2O where M=Ni & x =1; M=Co, Cd, Mn & x=3; and M=Zn, Cu & x =0 at pH 4. Analytical data confirms the compositions of the complexes. The acid shows dianionic nature in these complexes. The magnetic moments and electronic spectra suggest the geometry of the complexes. IR data indicates the nature of hydrazine and presence of water in the complexes. Simultaneous TG-DTA studies shows different thermal degradation patterns for the two types of complexes. The first type shows formation of no stable intermediates whereas the second type shows the respective metal hydroxy naphthoate intermediates. The final products in both the types are found to be metal oxides of nano size. XRD patterns show isomorphism among the complexes with similar molecular formulae.

Specificity in the interaction between poly(L-glutamate) and iron (III) complex ions in aqueous solution

Biopolymers ◽  
1976 ◽  
Vol 15 (11) ◽  
pp. 2219-2226 ◽  
Author(s):  
M. Branca ◽  
M. E. Marini ◽  
B. Pispisa
Keyword(s):  
Aqueous Solution ◽  
Complex Ions
Sign in / Sign up

Export Citation Format

Share Document