Author: Alan ShawPublisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Synthesis and Reactivity Studies on Oxo and Sulphido Compounds of Early Transition Metals
Author: Alan ShawSynthesis and Reactivity Studies Om Oxo and Sulphido Compounds of Early Transition Metals
Author: A. ShawSynthesis, Reactivity and Mechanistic Studies on Oxo, Imido and Alkylidine Complexes of the Early Transition Metals
Author: Jonathan Paul MitchellSynthesis, reactivity and mechanistic studies on oxo, imido and alkylidene complexes of the early transition metals
Author: Jonathan Paul MitchellPublisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Synthesis and Reactivity of Dinitrogen, Oxo, and Nitrido Complexes of First Row Transition Metals Supported by Hydrotris(pyrazolyl)borate Ligands
Author: Daniel Clayton CumminsPublisher:
ISBN: 9780355735154
Category :
Languages : en
Pages : 281
Book Description
When 9 is reacted with single oxygen atom transfer reagents the novel bridging oxo complex in the form of [TpFc,MeFe] 2(μ2-η1:η1-O) (16) is produced. 16 is only the second instance of such a FeII-O-FeII compound to have been isolated and structurally characterized. In the effort to produce additional chalcogenide compounds the complexes TpFc,MeFeOCPh3 (13) and TpFc,MeFeSCPh3 (14) were produced by salt metathesis with 3. The reaction of 14 with KH in the presence of 18-crown-6 to produce a bridging sulfide, [Tp Fc,MeFe]2(μ2-η1:η 1-S) (15). Attempts to produce imide compounds to act as isoelectronic models for terminal oxo compounds by reacting organic azides with 9 and 10 resulted in the production of tetrazene complex TpFc,MeCoN4Bn2 (17), as well as metallated azides TpFc,MeFeN3 (20) and TpFc,MeCoN3 (21).
Synthesis and Reactivity of Sulfur-rich Organometallic Compounds of the Early Transition Metals
Author: Cornelius Mark BolingerPublisher:
ISBN:
Category :
Languages : en
Pages : 466
Book Description
Organometallic Precursors to Compounds that Feature Transition Metal-main Group Element Multiple Bonds
Author: Benjamin Vincent MorkPublisher:
ISBN:
Category :
Languages : en
Pages : 640
Book Description
Transition Metals in the Synthesis of Complex Organic Molecules
Author: Louis S. HegedusPublisher:
ISBN:
Category : Science
Languages : en
Pages : 488
Book Description
The third edition of Transition Metals in the Synthesis of Complex Organic Molecules is a comprehensive revision and significant expansion of the second edition. The clear and systematic approach to the formation, manipulation, and reactivity of organometallic complexes has been maintained. The book is divided into 10 chapters starting with general formalisms, electron counting, and basic principles of organometallic reaction mechanisms. The organic chemistry of transition metals is then presented by class of metal complex, with many examples of applications in the synthesis of complex natural products and pharmaceuticals. The book is ideal for advanced undergraduate and graduate students as well as all practicing synthetic organic chemists. It is written for organic chemists and offers an easy entry into the field of organotransition metal chemistry without requiring a background in inorganic chemistry.
Dissertation Abstracts International
Author: Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 796
Book Description
Synthesis, Characterization and Reactivity Studies of Low-coordinate Late Transition Metal Complexes and the Preparation and Characterization of a Low-coordinate Samarium Complex
Author: Pei ZhaoPublisher:
ISBN: 9781339544052
Category :
Languages : en
Pages :
Book Description
This dissertation focuses on the synthesis, characterization and reactivity study of terphenyl ligand stabilized bis([mu]-oxo) dimeric iron and cobalt complexes. The synthesis and characterization of low-coordinate cobalt alkyl and iron alkyl complexes are also described. In addition, it describes the preparation of the first monomeric homoleptic solvent-free bis(aryloxide) lanthanide complex. The solid state structures of new compounds were determined by single crystal X-ray crystallography. Magnetic properties of paramagnetic compounds were measured by superconducting quantum interference device (SQUID) or Evans' methods for solid state or solution phase, respectively. The new compounds were also characterized by UV-Visible spectroscopy. Furthermore, infrared spectroscopy, Mössbauer spectroscopy, electron paramagnetic resonance spectroscopy, mass spectrometry, cyclic voltammetry and elemental analysis were employed to characterize some of the compounds when applicable. In some cases, DFT calculations were applied to elucidate the bonding and energy levels of molecular orbitals in the complexes. In Chapter 2, The bis([mu]-oxo) dimeric complexes {Ar[superscript iPr8]OM([mu]-O)}2 (Ar [superscript iPr8] = -C6H-2,6-(C6H2-2,4,6-[superscript i]Pr3)2-3,5-[superscript i]Pr2; M = Fe or Co) were prepared by oxidation of the metal (I) half-sandwich complexes {Ar[superscript iPr8]M([eta]6-arene)} (arene = benzene or toluene; M = Fe or Co). The iron species {Ar[superscript iPr8]OFe([mu]-O)}2 was prepared by reacting {Ar[superscript iPr8]Fe([eta]6-benzene)} with N2O or O2 and the cobalt species {Ar[superscript iPr8]OCo([mu]-O)}2 was prepared by reacting {Ar[superscript iPr8]Co([eta]6-toluene)} with O2. Both {Ar[superscript iPr8]OFe([mu]-O)}2 and {Ar[superscript iPr8]OCo([mu]-O)}2 were characterized by X-ray crystallography, UV-vis spectroscopy, magnetic measurements and, in the case of the iron species, by Mössbauer spectroscopy. The solid-state structures of both compounds reveal unique M2([mu]-O)2 (M = Fe or Co) cores with formally three-coordinate metal ions. The Fe···Fe separation in {Ar[superscript iPr8]OFe([mu]-O)}2 bears a resemblance to that in the Fe2([mu]-O)2 diamond core proposed for the methane monooxygenase intermediate Q. The structural differences between {Ar[superscript iPr8]OFe([mu]-O)}2 and {Ar[superscript iPr8]OCo([mu]-O)}2 are reflected in rather differing magnetic behavior. Compound {Ar[superscript iPr8]OCo([mu]-O)}2 is thermally unstable and its decomposition at room temperature resulted in the oxidation of the Ar[superscript iPr8] ligand via oxygen insertion and addition to the central aryl ring of the terphenyl ligand to produce the 5,5'-peroxy-bis[4,6-[superscript i]Pr2-3,7-bis(2,4,6-iPr3-phenyl)oxepin-2(5H)-one]. The structure of the oxidized terphenyl species is closely related to that of a key intermediate proposed for the oxidation of benzene. In Chapter 3, the homoleptic, cobalt(I) alkyl [Co{C(SiMe2Ph)3}]2 was prepared by reacting CoCl2 with [Li{C(SiMe2Ph)3}(THF)] in a 1:2 ratio though the initial intent was to synthesize a dialkyl cobalt (II) complex. Attempts to synthesize the corresponding iron(I) species led to the iron(II) salt [Li(THF)4][Fe2([mu]-Cl)3{C(SiMe2Ph)3}2]. Both complexes were characterized by X-ray crystallography, UV-vis spectroscopy, and magnetic measurements. The structure of [Co{C(SiMe2Ph)3}]2 consists of dimeric units in which each cobalt(I) ion is [sigma]-bonded to the central carbon of the alkyl group -C(SiMe2Ph)3 and [pi]-bonded to one of the phenyl rings of the -C(SiMe2Ph)3 ligand attached to the other cobalt(I) ion in the dimer. The structure of [Li(THF)4][Fe2([mu]-Cl)3{C(SiMe2Ph)3}2] features three chlorides bridging two iron(II) ions. Each iron (II) ion is also [sigma]-bonded to the central carbon of a terminal -C(SiMe2Ph)3 anionic ligand. The magnetic properties of [Co{C(SiMe2Ph)3}]2 reveal the presence of two independent cobalt (I) ions with S = 1 and a significant zero-field splitting of D = 38.0(2) cm−1. The magnetic properties of [Li(THF)4][Fe2([mu]-Cl)3{C(SiMe2Ph)3}2] reveal extensive antiferromagnetic exchange coupling with J = -149(4) cm−1 and a large second-order Zeeman contribution to its molar magnetic susceptibility. Formation of the alkyl [Co{C(SiMe2Ph)3}]2 and the halide complex [Li(THF)4][Fe2([mu]-Cl)3{C(SiMe2Ph)3}2] under similar conditions is probably due to the fact that Co(II) is more readily reduced than Fe(II). Some other synthetic routes were also attempted to synthesize a dialkyl cobalt (II) complex and they are described in this chapter. Neither [Co(NPh2)2]2 nor cobaltocene reacts with [Li{C(SiMe2Ph)3}(THF)] to afford a dialkyl cobalt (II) complex. Metathesis reactions of cobalt halides with lithium salts of alkyl ligand HCPh2R (R = -Ph or -SiMe3) resulted in the reduction of cobalt (II) to cobalt metal and the coupling of ligands, which indicate that homolytic cleavage of the cobalt-carbon bond was probably involved in the metathesis reactions. Furthermore, in chapter 4, reaction of Sm[N(SiMe3)2]2(THF)2 with two equivalents of bulky aryloxide ligand HOAr[superscript iPr6] (Ar[superscript iPr6] = -C6H3-2,6-(C6H2-2,4,6-[superscript i]Pr3)2) afforded the first monomeric homoleptic solvent-free bis(aryloxide) lanthanide complex Sm(OAr[superscript iPr6])2. The complex was characterized by crystallography, UV-Visible spectrum, IR and magnetically by the Evans' method. The O-Sm-O angle is bent at 111.08(9)̊. The samarium ion in Sm(OAr[superscript iPr6])2 also shows weak interactions with the flanking aryl rings of the terphenyloxide ligands. The complex is paramagnetic at room temperature with magnetic moment of 3.51 [mu]B.