Download or read book Studies of Low Oxidation State Main Group Complexes written by Richard P. Rose and published by . This book was released on 2006 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Studies of Low Oxidation State Group 14 Complexes and Their Reactivity Towards Small Molecules written by Jiaye Li and published by . This book was released on 2013 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis concerns research into the synthesis of low oxidation state group 14 complexes and their reactivity towards small molecule activation. A number of group 14 complexes in the +1 or +2 oxidation states have been synthesized. These include the first singly-bonded amido germanium(I) complex (amido-digermyne, [LGeGeL], L = {N(MeAr)(SiMe3)}, MeAr = C6H2{C(H)Ph2}2Me-2,6,4), amido group 14 metal(II) halide complexes, e.g. [LECl] (E = Ge, Sn or Pb, SiR3 = SiMe3, SiPh2Me or SiPh3), and amido silicon(IV) halide complexes, e.g. [LSiX3] (X = Cl or Br). The reactivity of the amido digermyne towards a variety of small molecules, e.g. H2, CO2, N2O, CS2, alkynes, etc., has been examined. In addition, the synthesis of "one-coordinate" group 14 metal(II) monocationic complexes (e.g. [LE]+[PF]-, E = Ge or Sn, PF = [Al{OC(CF3)3}4]- ) has been investigated and their reactivity towards Lewis base molecules has been examined. Work included in this thesis can be divided into six chapters. Chapter 1 introduces recent developments in main group chemistry, bonding in low oxidation state main group compounds, kinetic stabilization, and the "inert pair" effect. Some examples of low oxidation state main group complexes are described.Chapter 2 introduces the synthesis and coordination chemistry of a series of bulky secondary amines, [(MeAr)(SiR3)NH], [(iPrAr)(SiMe3)NH] (iPrAr = C6H2{C(H)Ph2}2iPr-2,6,4) and [(tBuAr)(SiR3)NH] (tBuAr = C6H2{C(H)Ph2}2tBu-2,6,4). Subsequently, the chapter discusses the synthesis of amido group 14 metal(II) halide complexes, e.g. [LECl] (E = Ge, Sn or Pb; SiR3 = SiMe3, SiPh2Me or SiPh3), [{(iPrAr)(SiMe3)N}ECl] (E = Ge or Sn) and {(tBuAr)(SiMe3)N}GeCl. The structures of these complexes have been determined using X-ray crystallography. Furthermore, amido silicon(IV) halide complexes, [LSiX3] (SiR3 = SiMe3, SiPh2Me or SiPh3; X = Cl or Br) and [{(iPrAr)(SiR3)N}SiBr3], as well as an amido silicon hydride, [LSi(H)Cl2] have been synthesized and structurally investigated. Chapter 3 discusses the synthesis and structural characterization of the first singly-bonded amido-digermyne, [LGeGeL], and its reactivity towards small gas molecule activation, e.g. that of H2, CO2, N2O, etc. at ambient and low temperatures. These reactions produced bulky amido germanium(II) and germanium(III) hydride complexes, and a bis(germylene) oxide complex. Further efforts have been devoted to the reactivity of [LGeGeL] towards molecules such as CS2, tBuNC and tBuNCO. Chapter 4 expands on the reactivity of [LGeGeL] and [L#GeGeL#] (L# = (iPrAr)(SiiPr3)N). It describes reactions that have been carried out with organic molecules, e.g. cyclooctatetraene (COT), 4-dimethylaminopyridine (DMAP), azobenzene, 1,4-bis(trimethylsilyl)butadiyne, norbornadiene, etc. These reactions produced a number of low oxidation state germanium complexes. In general, the reactions of [LGeGeL] and [L#GeGeL#] with unsaturated molecules produced products with the substrate inserted into the Ge-Ge bond. However, the reaction with DMAP produced a bis-adducted germanium complex with a shortened Ge-Ge bond. Finally, reactions of [LGeGeL] with chlorinated compounds, iodine, and ketones are discussed. Chapter 5 summarizes investigations into the synthesis and coordination chemistry of the first examples of bulky amido "one-coordinate" germanium(II) and tin(II) monocationic complexes, [LE]+[PF]- (E = Ge or Sn, PF = [Al{OC(CF3)3}4]-) and [L'Sn]+[PF]- (L' = [(MeAr)(SiPh2Me)N]). Their reactivity towards DMAP was investigated, and this led to two-coordinate adducted germanium or tin cationic complexes. Chapter 6 summarizes miscellaneous results, and consists of two sections. The first section discusses theoretical investigations into the Mo-Ge bonding of singly-bonded or triply-bonded molybdenum germylene and germylyne complexes. Wiberg bond indices (WBI) were acquired to provide a quantitative description of the bonding in these complexes. The second section focuses on investigations into the synthesis of a bulky gallium(I) amide complex, [LGa:], which was prepared from the reaction of [{(MeAr)(SiMe3)N}Li] and "GaI". X-ray crystallographic studies of [LGa:] were carried out and indicate that the complex is essentially one-coordinate.

Download or read book On the Catalytic Efficacy of Low Oxidation State Group 14 Complexes written by Terrance John Hadlington and published by Springer. This book was released on 2017-02-14 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: This outstanding thesis describes a detailed investigation into the use of low-oxidation-state group 14 complexes in catalysis, developed at the cutting edge of inorganic and organometallic chemistry. It includes the preparation of a number of landmark compounds, some of which challenge our current understanding of metal–metal bonding and low-oxidation-state main group chemistry. Among the many highlights of this thesis, the standout result is the development of the first well-defined, low- oxidation-state main group hydride systems as highly efficient catalysts in the hydroboration of carbonyl substrates, including carbon dioxide, which are as efficient as those observed in more traditional, transition-metal catalyses. These results essentially define a new subdiscipline of chemistry.

Download or read book Studies of Low Oxidation State Group 13 and 14 Metallacycles written by William Douglas Woodul and published by . This book was released on 2011 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis is mainly concerned with investigations into the reactivity of the gallium(I) N-heterocyclic carbene (NHC) analogue, [K(tmeda)][:Ga{[N(Dip)C(H)]2}] (Dip = C6H3Pri2-2,6). The preparation of the first monomeric Ge(I) radical was also investigated. Work carried out in these areas is divided into five chapters. Chapter 1 provides a general introduction to sub-valent group 13 and 14 chemistry, with an emphasis on the preparation of group 13 metal(I) and group 14 metal(II) N-heterocyclic carbene analogues. Chapter 2 summarizes investigations into the reactivity of [K(tmeda)] [:Ga{[N(Dip)C(H)]2}] towards groups 2 and 12 metal precursors. Reactions of magnesium, calcium, strontium, barium, zinc, and cadmium halides with [K(tmeda)][:Ga{[N(Dip)C(H)]2}] are discussed, and the first structurally characterized cadmium-gallium bonded molecular complex is reported. Chapter 3 summarizes investigations into the reactivity of [K(tmeda)] [:Ga{[N(Dip)C(H)]2}] towards selected lanthanide metal precursors. Reactions of samarium(II), europium(II), ytterbium(II), thulium(II), and cerium(III) iodides with [K(tmeda)][:Ga{[N(Dip)C(H)]2}] have given rise to a number of novel lanthanide-gallyl species, including the first structurally characterized GaTm or GaSm bonded complexes. Chapter 4 details the preparation of the first monomeric Ge(I) radical via the reduction of a bulky [beta]-diketiminato germanium(II) precursor. The verification of the +1 oxidation state in this species was achieved using a combination of crystallographic, EPR and ENDOR spectroscopic, and theoretical analyses. Chapter 5 describes several miscellaneous results, largely derived from attempts to prepare bulky guanidinato complexes of p-block elements in low oxidation states.

Download or read book Studies of Low Oxidation State Group 13 Halide Hydride and Heterocyclic Complexes written by Marc Kloth and published by . This book was released on 2004 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Studies of Low Valent Main Group and Transition Metal Complexes Supported by Nitrogen based Ligands written by Audra Faye Lugo and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Synthesis and Stabilisation of Low Oxidation State Complexes Utilising Magnesium I Dimers as Reducing Agents written by Simon James Bonyhady and published by . This book was released on 2013 with total page 594 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis pertains to the synthesis and stabilisation of low oxidation state main group element complexes through the utilisation of novel magnesium(I) dimers as reducing agents. As such, it is an exploration of the utility of these magnesium(I) complexes in organometallic synthesis and has resulted in the isolation of a number of compounds featuring unusual structural motifs, oxidation states and bonding modes.Chapter 1 provides a general introduction to low oxidation state main group chemistry and discusses a number of concepts that are unique to this field of study. Particular attention is paid to historical concepts such as the "double bond rule" and the new understanding of chemical bonding that has developed as a result of this "renaissance" in main group chemistry, as well as a general discussion of synthetic methods to access these compounds.Chapter 2 introduces the magnesium(I) dimers reported to date and details both their synthesis and reactivity in organic and organometallic synthesis. Two new [beta]-diketiminato magnesium(I) complexes are described, along with their [beta]-diketiminato magnesium(II) halide precursor complexes, and efforts towards improving the synthesis of these unusual compounds are outlined. A number of other novel [beta]-diketiminato magnesium(II) hydride, alkyl and halide complexes are also presented. Finally, efforts towards the synthesis of soluble models of magnesium amido-boranes, in which this library of magnesium(I and II) complexes is exploited, are also discussed.Chapter 3 presents a case study into the utility of magnesium(I) dimers as reducing agents in organometallic synthesis. A series of amidinato group 14 element(I) dimers [LEEL] (E = Si, Ge, Sn; L = amidinate) were synthesised in high to moderate yield, and comparisons between the magnesium(I) dimers and traditional reducing agents emphasised the efficacy of the magnesium(I) dimers in this role. The tin compound is the first of its type, while one and two previous examples exist for the silicon and germanium complexes, respectively, although they were only isolated in low yield.Chapter 4 describes the development of low oxidation state aluminium hydride chemistry, an area in which magnesium(I) dimers have been instrumental. A number of novel compounds are presented including of a series of compounds which feature remarkable [Al6H6] octahedral cores.Chapter 5 details efforts to extend the use of magnesium(I) dimers to compounds stabilised by bulky terphenyl ligands. The preparation of the second example of a diplumbyne, for which a moderate yielding synthesis was determined, is described. A dialumene and a disilyne were also desirable synthetic targets, and efforts to these ends are also outlined.Finally, Chapter 6 provides a summary of the results presented in this thesis.

Download or read book New approaches to the low oxidation state chemistry of some main group elements written by María Viviana Lomelí Tapuach and published by . This book was released on 1998 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Low Oxidation State Group 15 Cations written by Bobby Dean Ellis and published by . This book was released on 2006 with total page 478 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis Characterization and Reactivity of Some Low coordinate Low oxidation State Heavier Main Group 14 Element Species written by Madison Louis McCrea-Hendrick and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation describes the synthesis, characterization and reactivity of some low-coordinate, low-oxidation state heavier main group 13 and 14 element species. Chapter 2 describes the reactivity of the heavier main group 13 element digallene, (GaAr[superscript iPr4])2, (Ar[superscript iPr4] = -C6H3-2,6-(C6H3-2,6-[superscript i]Pr2)2) with group 6 transition metal hexacarbonyls under photoirradiation to form the bis(gallanediyl) complexes, trans-bis(GaAr[superscript iPr4])2M(CO)4 (M = Cr, Mo, or W). The mechanism of formation of these products was investigated both computationally and experimentally. A postulated intermediate in their formation is the monogallanediyl complex, Ga(Ar[superscript iPr4])Mo(CO)5 which was synthesized by the reaction (GaAr[superscript iPr4])2 with two equivalents Mo(CO)5NMe3. (GaAr[superscript iPr4])2 was also reacted at 25°C with Co2(CO)8 to give Ga(Ar[superscript iPr4])Co2(CO)7, in which the gallanediyl fragment is bound to each cobalt atom in a bridging fashion. Chapter 3 is an extension of the work in Chapter 2 to the reactions of the heavier main group 14 element dimetallynes, (EAr[superscript iPr4])2 (E = Ge or Sn), with group 6 transition metal hexacarbonyls under photoirradiative conditions. These reactions afforded the products {Ar[superscript iPr4]EM(CO)4}2 (E = Ge or Sn; M = Cr, Mo, or W) which featured rhomboid E2M2 cores with Ar[superscript iPr4]E units bridging transition metal tetracarbonyl fragments, M(CO)4. Chapter 4 describes the reactions of the aryl tin(II) hydrides {Ar[superscript iPr6]Sn([mu]-H)}2 (Ar[superscript iPr6] = C6H3-2,6-(C6H2-2,4,6-[superscript i]Pr6)2) and {Ar[superscript iPr4]Sn([mu]-H)}2 with phenyl acetylene and diphenyl acetylene. The reactions with diphenyl acetylene affords simple insertion of the Sn-H bond into a [pi]-bond of the alkyne to yield the products ArSnC(Ph)C(H)Ph (Ar = Ar[superscript iPr6] or Ar[superscript iPr4]). In contrast, the reaction of {ArSn([mu]-H)}2 with phenyl acetylene affords different products that are connected with the presence (Ar[superscript iPr6]) or absence (Ar[superscript iPr4]) of an isopropyl group at the remote para position of the flanking aryl rings of the terphenyl substituent. When {Ar[superscript iPr6]Sn([mu]-H)}2 is reacted with phenyl acetylene the product Ar[superscript iPr6](H)SnC(H)C(Ph)Sn(H)Ar[superscript iPr6] containing a 1,2-distannacyclobut-3-ene moiety is obtained as a colorless solid. In contrast, the reaction of {Ar[superscript iPr4]Sn([mu]-H)}2 with phenyl acetylene affords a red product of formula Ar[superscript iPr4]SnC(H)C(Ph)Sn(H)2Ar[superscript iPr4] with the tin atoms having different oxidation states of +2 and +4 as determined by solution 119Sn NMR spectroscopy. Chapter 5 describes the synthesis and characterization of the most sterically congested tetrylenes currently known: E(Ar[superscript iPr6])2 (E = Ge, Sn, or Pb). Computational studies of these tetrylenes and E(Ar[superscript Me6])2 (Ar[superscript Me6] = C6H3-2,6-(C6H2-2,4,6-Me3)2) and E(Ar[superscript iPr4])2 were also performed with and without dispersion corrections to evaluate the contribution of London dispersion force effects on the C[subscript ipso]-E-C[subscript ipso] interligand angle.

Download or read book Exploring the Synthesis and Coordination Chemistry of Zwitterionic Main Group Compounds written by Jonathan William Dube and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Traditionally low coordinate and low oxidation state main group compounds are isolated utilizing hard anionic donors based on carbon and nitrogen based ligands. Conversely, employing anionic phosphines for this role has been essentially unexplored. In this context, this dissertation describes the synthesis of a number of main group complexes, ranging from group 13 to group 15, utilizing the bis(phosphino)borate ligand class in a supporting role. The remote anionic borate backbone renders the complexes zwitterionic and provides access to unique compounds that possess structures, and exhibit onwards reactivity, that is very different to the analogous compounds stabilized with neutral phosphines. For example, chapter two describes the stabilization of formally positively charged triel ({Ga2I4}2+) and tetrel ({GeCl}+ and {SnCl}+) fragments via common low oxidation state precursors. These structures have no precedent with neutral phosphines and represent a stable and isolable main group element source that is ready for onwards chemistry. For the group 14 compounds, upon removal of the chloride substituent the reactive tetrel centre quantitatively inserts into the ligand backbone. Zwitterionic group 15 compounds were prepared in good yields exploiting known redox chemistry and possess a pnictogen atom (Pn = P, As) in the unusual +1 oxidation state (Chapter 3). The anionic backbone is shown to be critical in accessing the coordination chemistry of these compounds as there are very few examples of the traditional cationic variants being used in subsequent transformations. Both pnictogen proligands form isolable coordination compounds with chromium, molybdenum, tungsten, and iron carbonyl reagents (Chapter 4) while rhodium, palladium, and mercury complexes are also isolated with the phosphorus derivative (Chapter 5). This diverse range of products represents the first such series of transition metal complexes for these types of Pn(I) compounds. The highlight of the thesis is the discovery that the phosphorus proligand acts as a 4-electron -type ligand to two gold, cobalt, or platinum centres simultaneously. Such coordination chemistry is unprecedented and provides the first experimental evidence for the P(I) compound to be described as a phosphanide-type bonding arrangement. These novel structures further underscore the importance of the borate backbone in synthesizing compounds that have otherwise not been observed. Throughout the thesis all of the compounds were fully characterized using a range of solution and solid-state techniques, including single crystal X-ray crystallography, allowing for a detailed data comparison.

Download or read book The Group 13 Metals Aluminium Gallium Indium and Thallium written by Simon Aldridge and published by John Wiley & Sons. This book was released on 2011-02-10 with total page 990 pages. Available in PDF, EPUB and Kindle. Book excerpt: The last two decades have seen a renaissance in interest in the chemistry of the main group elements. In particular research on the metals of group 13 (aluminium, gallium, indium and thallium) has led to the synthesis and isolation of some very novel and unusual molecules, with implications for organometallic synthesis, new materials development, and with biological, medical and, environmental relevance. The Group 13 Metals Aluminium, Gallium, Indium and Thallium aims to cover new facts, developments and applications in the context of more general patterns of physical and chemical behaviour. Particular attention is paid to the main growth areas, including the chemistry of lower formal oxidation states, cluster chemistry, the investigation of solid oxides and hydroxides, advances in the formation of III-V and related compounds, the biological significance of Group 13 metal complexes, and the growing importance of the metals and their compounds in the mediation of organic reactions. Chapters cover: general features of the group 13 elements group 13 metals in the +3 oxidation state: simple inorganic compounds formal oxidation state +3: organometallic chemistry formal oxidation state +2: metal-metal bonded vs. mononuclear derivatives group 13 metals in the +1 oxidation state mixed or intermediate valence group 13 metal compounds aluminium and gallium clusters: metalloid clusters and their relation to the bulk phases, to naked clusters, and to nanoscaled materials simple and mixed metal oxides and hydroxides: solids with extended structures of different dimensionalities and porosities coordination and solution chemistry of the metals: biological, medical and, environmental relevance III-V and related semiconductor materials group 13 metal-mediated organic reactions The Group 13 Metals Aluminium, Gallium, Indium and Thallium provides a detailed, wide-ranging, and up-to-date review of the chemistry of this important group of metals. It will find a place on the bookshelves of practitioners, researchers and students working in inorganic, organometallic, and materials chemistry.

Download or read book Oxidation of Some Main Group Elements and Their Low Oxidation State Compounds by Substituted O benzoquinones written by Zhigang Tian and published by . This book was released on 1993 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Oxidation Numbers and Oxidation States written by Christian Klixbüll Jorgensen and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 295 pages. Available in PDF, EPUB and Kindle. Book excerpt: The correlation of spectroscopic and chemical investigations in recent years has been highly beneficial of many reasons. Around 1950, no valid explanation was available of the colours of compounds of the five tran sition groups. Later, it was possible to identify the excited levels with those expected for an electron configuration with adefinite number of electrons in the partly filled shell. I t is not generally recognized that this is equivalent to determining spectroscopic oxidation states related to the preponderant electron configuration and not to estimates of the fractional atomic charges. This brings in an entirely different type of description than the formal oxidation numbers used for characterizing compounds and reaction schemes. However, it must be realized that collectively oxidized ligands, formation of cluster-complexes and catenation may prevent the oxidation state from being well-defined. The writer would like to express his gratitude to many, but first of all to DR. CLAUS SCHÄFFER, University of Copenhagen, who is the most efficient group-theoretical engineer known to the writer; his comments and discussions have been highly valuable. The writer's colleague, Pro fessor FAUSTO CALDERAZZO (now going to the University of Pisa) has been most helpful in metallo-organic questions. Thanks are also due to Professors E. RANcKE-MADsEN and K. A. JENSEN for correspondence and conversations about formal oxidation numbers.

Download or read book The Organometallic Chemistry of the Transition Metals written by Robert H. Crabtree and published by John Wiley & Sons. This book was released on 2005-06-14 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fully updated and expanded to reflect recent advances, this Fourth Edition of the classic text provides students and professional chemists with an excellent introduction to the principles and general properties of organometallic compounds, as well as including practical information on reaction mechanisms and detailed descriptions of contemporary applications.

Download or read book Preparation Characterisation and Reactivity of Low Oxidation State d Block Metal Complexes Stabilised by Extremely Bulky Amide Ligands written by Jamie Hicks and published by Springer. This book was released on 2016-10-24 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes the synthesis and characterization of numerous metal-metal bonded complexes that are stabilized by extremely bulky amide ligands. It provides a comprehensive overview of the field, including discussions on groundbreaking complexes and reactions, before presenting in detail, exciting new findings from the PhD studies. The thesis appeals to researchers, professors and chemistry undergraduates with an interest in inorganic and/or organometallic chemistry.

Download or read book Novel beta diketiminates and beta diketiminate Derivatives for the Synthesis of Main Group Complexes written by Brant James Maitland and published by . This book was released on 2015 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis is primarily concerned with the synthesis of low oxidation state alkaline earth metal complexes featuring novel [beta]-diketiminate ligands and their derivatives. The syntheses of a variety of different [beta]-diketiminates possessing extreme steric bulk, as well as those that have been electronically modified are detailed. These ligands have been used to produce a variety of different alkali metal, alkaline earth metal and lanthanide complexes.Chapter 1 provides a general introduction to low oxidation state alkaline earth metal chemistry. Particular attention is given to metal complexes featuring [beta]-diketiminates, given their central role in the research making up this thesis.Chapter 2 deals with the synthesis of a range of novel, sterically hindered [beta]-diketimines. These pro-ligands were targeted in the belief that their extreme bulk would allow the synthesis of currently unknown structural motifs.Chapter 3 is primary concerned with the exploitation of the developed sterically hindered [beta]-diketimines in the synthesis of a variety of alkali metal, alkaline earth metal and lanthanide complexes. A range of three coordinate magnesium complexes were produced using the developed ligands, most notably, the first crystallographically characterised [beta]-diketiminato magnesium hydride. In our quest for a calcium(I) dimer, a complex type which is currently unknown, a variety of [beta]-diketiminato calcium iodides were produced. The attempted reduction of these heteroleptic metal iodide complexes resulted not in the targeted low oxidation state complexes, but in two different calcium(II) dimers.In Chapter 4, the [beta]-diketimine ligand was adapted, resulting in two separate classes of pro-ligands. The first, a 1,3,5-triazapentadiene, has had the central carbon replaced by nitrogen. The second, instead of having the typical methyl groups on the ligand backbone, has dialkylamino groups. In each instance, it was envisaged that the ligands would donate additional electron density, and bind more strongly to the metal centre in coordination complexes, when compared to the standard [beta]-diketiminate ligand class. Six separate heteroleptic magnesium(II) iodide complexes have been developed from these ligands, the majority of which show promise as precursors to low oxidation state magnesium complexes.Chapter 5 details several new secondary amines which have been produced as pro-ligands for low oxidation state main group chemistry. In addition, preliminary studies have shown that these ligands have potential in coordination chemistry.