Synthesis, Structure, Magnetic and Electronic Properties of Heterometallic Complexes Containing First-Row Transition Metals PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Synthesis, Structure, Magnetic and Electronic Properties of Heterometallic Complexes Containing First-Row Transition Metals PDF full book. Access full book title Synthesis, Structure, Magnetic and Electronic Properties of Heterometallic Complexes Containing First-Row Transition Metals by Tao Huang. Download full books in PDF and EPUB format.
Author: Tao Huang
Publisher:
ISBN:
Category :
Languages : en
Pages : 303
Get Book Here
Book Description
Author: Tao Huang
Publisher:
ISBN:
Category :
Languages : en
Pages : 303
Get Book Here
Book Description
Author: Michael Brett Meredith
Publisher:
ISBN:
Category : Isomerism
Languages : en
Pages : 380
Get Book Here
Book Description
Author: Zhiqiang Xu
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
This thesis describes the structures and the magnetic properties of the first row transition metal complexes containing open-chain diazine (N-N) moieties. The purpose of the research is to establish a magnetostructural correlation involving the N-N single bond bridge and to investigate the coordination chemistry of open-chain diazine ligands to the first row transition metal ions. A relevant literature search is presented in Chapter 1. -- Chapter 1 describes a general introduction to magnetic exchange in polynuclear copper complexes and a general review of the coordination chemistry of diazine (N2) bridged complexes. In Chapter 2, seventeen dicopper(II) complexes with five open-chain diazine ligands (PAHAP, PMHAP, PHMAP, PHAAP and PYPZ) are reported, in which the two copper(II) centers are bridged by a single N-N bond only. The X-ray structures of one ligand and twelve dinuclear copper(II) complexes were determined. Changing the ligands, together with varying the coligands leads to a situation where the dihedral angle between the copper planes can be varied from 75° to 168.5°. For small angles (less than 80°) ferromagnetic coupling prevails, whereas at larger angles antiferromagnetic exchange is observed between the copper(II) centers. The exchange integrals (-2J) vary from -24.4 to 210 cm−1. This is associated with the degree of alignment of the nitrogen p orbitals in the diazine bridge, and is supported by molecular orbital calculations on the complexes and appropriate models. Chapter 3 deals mainly with dinuclear copper(II) complexes containing two ligands bridging two metal centers. The dinuclear copper(II) complexes containing two N-N single bonds have no or very weak coupling because of orbital orthogonality and the twisting of the two copper planes around these two N-N single bonds. A dicopper complex containing mixed diazine bridges (pyridazine/N-N) shows weak antiferromagnetic coupling, and since the diazine unit in the aromatic ring system bridges two copper centers in an orthogonal manner, this net antiferromagnetic coupling occurs only through the open-chain diazine bridge. A tetranuclear copper complex contains two pairs of dicopper(II) centers bridged orthogonally by two μ2-1,1-azide anions with each pair of copper(II) centers bridged by one N-N single bond and one μ2-1,1-azide with a 119° azide bridge angle. The dihedral angle about the N-N single bond is 54°, which indicates either no coupling or weak ferromagnetic coupling via such a bridge. Therefore, the strong antiferromagnetic coupling (-2J = 246 cm−1 ) occurs only through the μ2-1,1-azide bridges between each pair of copper(II) centers, giving the first genuine example contradicting the spin polarization mechanism associated with azide bridges. In Chapter 4, a series of spiral-like dinuclear complexes of Mn(II), Fe(II), Fe(III), Co(II), Co(III) and Ni(II) ions containing three N-N single bonds with a formula [L3M2].(X)n.mH2O (L = PAHAP, PZHPZ; X = CIO4 or NO3; n = 4, 6) and a seven-coordinate Fe(III) complex are discussed. The X-ray structures of six of these complexes have been determined. Variable-temperature magnetic properties, electrochemistry and spectra are discussed. Chapter 5 discusses the synthesis, structural and magnetic properties of some mononuclear and polynuclear first row transition metal complexes of the open-chain diazine ligands. The X-ray structures of eight complexes were determined. Two new coordination modes for open-chain diazine ligands have been found. In the last chapter, a general conclusion about coordination modes, magnetostructural correlations, etc. of the open-chain diazine complexes is made.
![Synthesis and Reactivity of Transition Metal Complexes Bearing the Tridentate Bis(2-mercapto-p-tolyl)amine ([SNS]H 3) Ligand PDF](https://books.google.com/books/content/images/frontcover/yhZvswEACAAJ?fife=w80-h100)
Author: Kyle Evan Rosenkoetter
Publisher:
ISBN: 9780355307856
Category :
Languages : en
Pages : 196
Get Book Here
Book Description
The work described herein focuses on the synthesis and characterization of new heterobimetallic complexes containing the redox-active W[SNS] 2 metalloligand and investigation into their electronic properties and reactivity. Most recent studies have explored the redox nature of the [SNS]H 3 scaffold through the synthesis and reactivity of a novel set of square-planar nickel complexes.Chapters 2 and 3 describe a modular synthetic approach towards generating a new series of heterobimetallic complexes with the general formula W[SNS]2M(L) ([SNS] = bis(2-mercapto- p-tolyl)amine; M = Ni, Pd, or Pt; and L = dppe, depe, dmpe, dppp, PR'2NRPR'2 (R = phenyl, benzyl; R'=phenyl), DPEphos or dppf). The complexes were prepared by a salt metathesis of Cl2MII(L) with the previously reported W[SNS]2 coordination complex under reducing conditions. X-ray diffraction analysis revealed interesting coordination geometries about the appended Group 10 metal centers moving from Pt and Pd (pseudo-square planar) to the first row Ni (pseudo-tetrahedral) analogue. These complexes demonstrate formal metal--metal bond formation across the series with a tunable first oxidation potential up to 600 mV.Chapter 4 investigates the use of W[SNS]2Ni(dppe) as a catalyst for the electrochemical reduction of protons to hydrogen. This complex was found to catalytically generate hydrogen with an overpotential of 700 mV, a TOF of 14 sec--1, and a Faradaic yield of 80 +/- 3 % using 4-cyanoanilinium tetrafluoroborate in non-aqueous solutions.Chapter 5 demonstrates the effect of exchanging the nickel center of the heterobimetallic complexes discussed in Chapters 2 and 3 with other first row transitions metal ions (i.e. cobalt and copper). Analysis into the observed metal--metal distances reveal stark differences across the series. Additionally, the copper ion containing complexes demonstrate dynamic behavior in solution.Chapter 6 investigates the synthesis and reactivity of a series of monomeric square-planar nickel complexes of the [SNS] scaffold to demonstrate the ligand as redox, proton, and hydrogen atom non-innocent.Appendix A illustrates the electrochemical responses observed for the monoanionic complexes from Chapter 6 in the presence of CO2 and CO. Appendices B and C describe the synthesis and characterization of a five-coordinate cobalt and a heterotrimetallic tungsten-nickel complex, respectively.
Author: Sarah Mcdougall
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Get Book Here
Book Description
Author: Jessica Nicole Boynton
Publisher:
ISBN: 9781321210804
Category :
Languages : en
Pages :
Get Book Here
Book Description
The research in this dissertation is focused on the synthesis, structural, and magnetic characterization of two-coordinate open shell (d1-d4) transition metal complexes. Background information on this field of endeavor is provided in Chapter 1. In Chapter 2 I describe the synthesis and characterization of the mononuclear chromium (II) terphenyl substituted primary amido complexes and a Lewis base adduct. These studies suggest that the two-coordinate chromium complexes have significant spin-orbit coupling effects which lead to moments lower than the spin only value of 4.90 [mu]B owing to the fact that [lambda] (the spin orbit coupling parameter) is positive. The three-coordinated complex 2.3 had a magnetic moment of 3.77 [mu]B. The synthesis and characterization of the first stable two-coordinate vanadium complexes are described in Chapter 3. The values suggest a significant spin orbital angular momentum contribution that leads to a magnetic moment that is lower than their spin only value of 3.87 [mu]B. DFT calculations showed that the major absorptions in their UV-Vis spectra were due to ligand to metal charge transfer transitions. The titanium synthesis and characterization of the bisamido complex along with its three-coordinate titanium(III) precursor are described in Chapter 4. Compound 4.1 was obtained via the stoichiometric reaction of LiN(H)AriPr 6 with the Ti(III) complex TiCl3 *2NMe3 in trimethylamine. The precursor 4.1 has trigonal pyramidal coordination at the titanium atom, with bonding to two amido nitrogens and a chlorine as well as a secondary interaction to a flanking aryl ring of a terphenyl substituent. Compound 4.2 displays a very distorted four-coordinate metal environment in which the titanium atom is bound to two amido nitrogens and to two carbons from a terphenyl aryl ring. This structure is in sharp contrast to the two-coordinate linear structure that was observed in its first row metal (V-Ni) analogs. The synthesis and characterization of mononuclear chromium(II) terphenyl primary substituted thiolate complexes are described in Chapter 5. Reaction of the terphenyl primary thiolate lithium derivatives LiSAriPr4 and LiSArMe6 with CrCl2THF2 in a 2:1 ratio afforded complexes 5.1 and 5.2, which are the very rare examples of chromium(II) thiolates with quasi-two-coordination at the metal center. Both deviate from linearity and have S-Cr-S angles of 111.02(3)° and 107.86(3)° with secondary Cr-C(aryl ring) interactions of ca. 2.115 Å and 1.971 Å respectively. The initial work on titanium and vanadium terphenyl thiolates is described in Appendix I and II. In Chapter 6 I show that the reaction of K2COT (COT= 1,3,5,7-cyclooctatetraene, C8H8) with an aryl chromium(II) halide gave (CrAriPr4)2([mu]2-n3:n4-COT) (6.1) in which a non-planar COT ring is complexed between two CrAriPr4 moieties -- a configuration previously unknown for chromium complexes of COT. OneCr2+ ion is bonded primarily to three COT carbons (Cr--C= 2.22-2.30 Å ) as well as an ipso carbon (Cr-C= ca. 2.47 Å) from a flanking aryl ring of its terphenyl substituent. The other Cr2+ ion bonds to an ipso carbon (Cr-C= ca. 2.53 Å) from its terphenyl substituent as well as four COT carbons (Cr--C= 2.24-2.32 Å). The COT carbon-carbon distances display an alternating pattern, consistent with the non-planarity and non-aromatic character of the ring. The magnetic properties of 6.1 indicate that the Cr2+ ions have a high-spin d4 configuration with S = 2. The temperature dependence of the magnetism indicates that their behavior is due to zero-field splitting of the S = 2 state. Attempts to prepare 6.1 by the direct reaction of quintuple-bonded (CrAriPr4)2 with COT were unsuccessful. (Abstract shortened by UMI.) --Proquest.
Author: Daniel Patrick Murtha
Publisher:
ISBN:
Category : Ketones
Languages : en
Pages : 198
Get Book Here
Book Description
Author: Dante Gatteschi
Publisher: OUP Oxford
ISBN: 0191620858
Category : Science
Languages : en
Pages : 416
Get Book Here
Book Description
Nanomagnetism is a rapidly expanding area of research which appears to be able to provide novel applications. Magnetic molecules are at the very bottom of the possible size of nanomagnets and they provide a unique opportunity to observe the coexistence of classical and quantum properties. The discovery in the early 90's that a cluster comprising twelve manganese ions shows hysteresis of molecular origin, and later proved evidence of quantum effects, opened a new research area which is still flourishing through the collaboration of chemists and physicists. This book is the first attempt to cover in detail the new area of molecular nanomagnetism, for which no other book is available. In fact research and review articles, and book chapters are the only tools available for newcomers and the experts in the field. It is written by the chemists originators and by a theorist who has been one of the protagonists of the development of the field, and is explicitly addressed to an audience of chemists and physicists, aiming to use a language suitable for the two communities.
Author: Charles E. Jr. Carraher
Publisher: Elsevier
ISBN: 0323153909
Category : Science
Languages : en
Pages : 368
Get Book Here
Book Description
Organometallic Polymers focuses on the synthesis, characterization, and potential applications of organometallic polymers. The discussion is organized around seven themes: vinyl polymerization of organometallic monomers; condensation polymerization of organometallic monomers; polymer-bound catalysts; applications of organotin polymers; developments in organosilicon polymers; phosphonitrile and sulfur nitride polymers; and coordination polymers. This book is comprised of 33 chapters and begins with a general review of polymerized vinyl monomers containing transition metals, as well as the reactivity of such monomers in addition to homo- and copolymerizations. The following chapters explore the participation of the ferrocene nucleus in the polymerization of vinylferrocene and its effect on polymer properties; thermomechanical transitions of ferrocene-containing polymers; photocrosslinkable organometallic polyesters; and supported catalysts for ethylene polymerization. The remaining sections discuss antifouling applications of various tin-containing organometallic polymers; structure and applications of polyphosphazenes and polymeric sulfur nitride; and coordination of inorganic ions to polymers. This monograph will be a useful resource for organic chemists and research workers in the field.
Author: Barbara Sieklucka
Publisher: John Wiley & Sons
ISBN: 3527339531
Category : Science
Languages : en
Pages : 508
Get Book Here
Book Description
A comprehensive overview of this rapidly expanding interdisciplinary field of research. After a short introduction to the basics of magnetism and molecular magnetism, the text goes on to cover specific properties of molecular magnetic materials as well as their current and future applications. Design strategies for acquiring molecular magnetic materials with desired physical properties are discussed, as are such multifunctional materials as high Tc magnets, chiral and luminescent magnets, magnetic sponges as well as photo- and piezo-switching magnets. The result is an excellent resource for materials scientists, chemists, physicists and crystal engineers either entering or already working in the field.
