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2 edition of Lanthanide and transition metal complexes of nitrogen and oxygen donor macrocyclic ligands. found in the catalog.

Lanthanide and transition metal complexes of nitrogen and oxygen donor macrocyclic ligands.

Evagoras George Evagorou

# Lanthanide and transition metal complexes of nitrogen and oxygen donor macrocyclic ligands.

## by Evagoras George Evagorou

Published .
Written in English

Edition Notes

The Physical Object ID Numbers Contributions University of North London. Pagination xiv,263,11p. Number of Pages 26311 Open Library OL13766478M

Macrocyclic complexes of transition metal ions have received great attention due to their biological activities, including antiviral, anticarcinogenic 8, antifertile 9, antibacterial and antifungal Some Macrocyclic complexes of lanthanides e.g. Gd 3+ are used as MRI contrast enhancing agents Macrocyclic Nickel complexes have been.   A new macrocyclic Schiff base complexes were prepared in the presence of lanthanide metal ion[La(III), Ce(III) and Gd(III)] by the reaction of 2,6 – diamino pyridine, benzoyl aceton and metal ion as template effect in the molar ratio of 2: 2: 1 respectively. The lanthanide metal complexes were characterized and investigated by using; 1HNMR, FTIR, UV/Visible spectroscopy, Elemental analysis.

Although lanthanide double-decker complexes with hetero-macrocyclic ligands as functional luminescent and magnetic materials have promising .   Thus theoretical approach adopted to study pyridine binding to metals using pyridine ligands to a group of first transition metals ions in their +2 oxidation states. DFT calculation employed by Rodgers [ 95 ] to determine the ground state structure and sequential binding energies of [M 2+ (Py) x ] complexes, where x = 1–6 and M = Fe 2+, Co 2.

phonate arms form metal complexes with the required properties for these applications [1–4]. Structural factors such as cavity size, rigidity of the macrocyclic backbone, and type and position of donor atoms play a significant role in the binding of macrocycles to metal cations [4,5]. The introduction of N-sub-. The doubly deprotonated ligand contains strong donors, namely phenolato oxygen atoms as well as imine nitrogen atoms bearing excellent coordination ability with transition/inner transition metal ions through its N x O y donor set (Zheng et al., ). As a part of our systematic investigation (Abid & Al-barody, ; Abid, Al-Barody, & Ahmad.

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### Lanthanide and transition metal complexes of nitrogen and oxygen donor macrocyclic ligands by Evagoras George Evagorou Download PDF EPUB FB2

The tridentate N-donor ligand () forms square-planar Ir I chloro complexes through coordination to the three N-donor atoms. Attempts to exchange directly the chloride ligand for hydride and methyl ligands were unsuccessful.

However, routes were developed to the reactive methoxide and triflate complexes, which proved to be excellent starting materials for the synthesis of Ir I and Ir III. This thesis is concerned with the synthesis and characterisation of altogether twenty and membered macrocyclic ligands, incorporating the pyridyl and phenolic substituents in the cavity, coupled with their lanthanide and transition metal complexes.

Initially a survey of the synthesis and characteristics of related macrocycles is : Evagoras George Evagorou. Binuclear and polynuclear transition metal complexes with macrocyclic ligands 7. Directed step-by-step synthesis of novel unsymmetric macrocyclic ligands. Russian Chemical Bulletin54 (9), DOI: / by:   In these complexes the polypyridine part of the ligand plays a manifold role, e.g.

(i) structural element that determines the topology of the free ligands and of their complexes, (ii) coordination element that provides additional nitrogen binding sites for the lanthanide cation and (iii) sensitization element that, due to its photophysical Cited by: 1.

Introduction. Schiff base metal complexes have a key role in the development of coordination chemistry,resulting in an enormous number of publications, ranging from pure synthetic work to modern physicochemical and biochemically relevant studies of metal complexes [].The lanthanide cations can promote Schiff base condensation and can give access to complexes of otherwise inaccessible by: 2.

Complexes of the lanthanides with neutral oxygen donor ligands. In book: Novel Aspects, pp The thermal properties of the metal complexes were studied under nitrogen atmosphere in. Synthesis and Metal Complex Formation of Nitrogen-Oxygen Donor Macrocyclic Ligands.

Zeitschrift f r anorganische und allgemeine Chemie(5), DOI: /zaac Uwe Kallert, Rainer Mattes. A macrocyclic approach to transition metal and uranyl Pacman complexes Jason B.

Love Received (in Cambridge, UK) 2nd MarchAccepted 18th March First published as an Advance Article on the web 27th April DOI: /bc Multielectron redox chemistry involving small molecules such as O 2,H 2O, N 2,CO 2, and CH 4 is.

Abstract. Macrocyclic ligands have traditionally been divided into two classes, those with oxygen donors, such as the crown ethers and cryptands, discovered by Pedersen 1 and Lehn, 2 and the nitrogen donor macrocycles, first investigated by workers such as Curtis 3 and Busch.

4 The sulfur-donor macrocycles 5–7 resemble the nitrogen donor macrocycles more closely in their coordinating. The coordination of the nitrate ion and the water molecule in each complex illustrates the influence of oxygen donor ligand to stabilize the lanthanide(III) cations in the macrocyclic framework.

The yield of the complexes of L2 increases with decreasing ionic radii of the metal ions. The crystal structure of complex 4 (Figure 1(a)) consists of cationic complexes [Yb(NO 3) 2 L] +, nitrate anions, and two methanol molecules per metal ion held together with hydrogen bonds and C–H π interactions.

The atom, being ten coordinated, is surrounded by six oxygen atoms belonging to two bidentate chelating nitrato ligands and to the etherate part of the ligand and four (two imino. Lanthanide and transition metal complexes of nitrogen and oxygen donor macrocyclic ligands.

Author: Evagorou, Evagoras George. ISNI: Awarding Body: University of North London Current Institution: London Metropolitan University Date of Award.

Summary. The synthesis and characterization of some Co II, Ni II and Cu II complexes with a nitrogen-oxygen donor macrocyclic ligand is reported.

Analytical data, i.r. and visible spectra are compatible with an octahedral or distorted octahedral coordination around the metal. The kinetics of ML complex formation. The rate at which a ligand (L) forms a complex Gd(H 2 O) 8 3+ depends upon many factors including pH, temperature, concentration of reactants and, interestingly, whether the ligand is derived from a linear or macrocyclic poly-amine.

Given that pH, temperature and concentration can all be controlled, the one variable among these factors that remains is the. These complexes contain a central atom or ion, often a transition metal, and a cluster of ions or neutral molecules surrounding it. Ligands are ions or neutral molecules that bond to a central metal atom or ion.

Ligands act as Lewis bases (electron pair donors), and the central atom acts as a Lewis acid (electron pair acceptor). Ligands have at. Cobalt(II) salts combine with a tetradentate and hexadentate macrocyclic nitrogen/oxygen donor ligands and formed novel cobalt(II) complexes which are characterized by elemental analysis, molar.

Potentiometric and calorimetric data for the complexation of lanthanide(III) cations by the neutral nitrogen-donor ligands diethylenetriamine or triethylenetetramine in anhydrous dimethyl sulfoxide at 25 °C and in an ionic medium of mol dm –3 NEt 4 ClO 4 have been the complexes are strongly enthalpy stabilized while the entropy changes are unfavourable.

Synthesis of metal complexes with nitrogen donor macrocyclic ligands and their use as homogeneous catalysts investigation of carbene additions to alkene double bonds catalyzed by metal complexes of different chiral ligands Ligands with different structures have been tested, and some of them have afforded.

a variety of donor atoms with bridgehead nitrogen atoms.5 They are highly selective for alkali and alkaline earth metal ions. Compartmental Ligands Compartmental ligands (16) are macrocyclic ligands (as well as nonmacrocyclic ligands) which contain ‘compart-ments’ for housing more than one metal ion Only the.

Complex formation by lanthanides is different from that of actinides. In lanthanides, the $\mathrm{4f}$ orbitals are well shielded by the larger $\mathrm{5d}$ and $\mathrm{6s}$ orbitals and are deep inside the atom.

So $\mathrm{f}$ orbitals do not participate in any bonding and complex formation is similar to that of transition metals. The colors of lanthanide complexes originate almost entirely from charge transfer interactions between the metal and the ligand. f → f transitions are symmetry forbidden (or Laporte-forbidden), which is also true of transition metals.

However, transition metals are able to use vibronic coupling to break this rule. The valence orbitals in.Coordination Complexes. Coordination compounds, such as the FeCl 4-ion and CrCl 3 6 NH 3, are called such because they contain ions or molecules linked, or coordinated, to a transition are also known as complex ions or coordination complexes because they are Lewis acid-base complexes.

The ions or molecules that bind to transition-metal ions to form these complexes are called ligands.Grégory Nocton, Aline Nonat, Christelle Gateau, Marinella Mazzanti, Water Stability and Luminescence of Lanthanide Complexes of Tripodal Ligands Derived from 1,4,7‐Triazacyclononane: Pyridinecarboxamide versus Pyridinecarboxylate Donors, Helvetica Chimica Acta, /hlca, 92, 11, (), ().