Dissertations / Theses: 'Alkaline earth metals'

1

Ovchinnikov, Alexander. "Nitridomanganates of alkaline-earth metals." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-215891.

Full text

Abstract:

The main goal of the present work was the synthesis of alkaline-earth nitridomanganates (AExMnyNz) with extended anionic structures and the characterization of their electronic and magnetic properties. Up to now, only compounds with isolated nitridomanganate anions have been reported in the discussed ternary systems. A systematic exploratory synthesis, employing high-temperature treatment of AE nitrides and Mn under controlled N2 pressure, yielded more than ten new nitridomanganates. Their crystal structures contain anionic building blocks of different dimensionalities, ranging from isolated species to three-dimensional frameworks. In general, the formation of Mn-rich compositions was found to be driven by the emergence of Mn-Mn interactions, which creates a link between nitridometalates and transition-metal-rich binary nitrides. The obtained nitridomanganates display a plethora of interesting phenomena, such as large spin-orbit coupling, magnetic frustration, quenching of magnetism due to Mn-Mn interactions, and metal-insulator transition.

APA, Harvard, Vancouver, ISO, and other styles

2

Miller, Stewart Anthony Stephen. "Alkaline earth and cerium compounds." Thesis, University of Liverpool, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283730.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Day, S. "Neutron and optical spectroscopy of alkaline earth metals." Thesis, University of Oxford, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234944.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Elhiyani, Mohamed. "Study of helium clusters doped with alkaline-earth metals." Phd thesis, Université Paris-Est, 2009. http://tel.archives-ouvertes.fr/tel-00584392.

Full text

Abstract:

Ces dernières années, les agrégats d'hélium superfluides ont fait l'objet de nombreuses études aussi bien expérimentales que théoriques. Le fruit de ces études a permis le développement de méthodes spectroscopiques innovantes (HENDI) utilisant les nanogouttes d'hélium comme l'ultime matrice, exploitant ainsi la très faible température de ce milieu particulier et sa faible interaction avec les dopants pour une meilleure résolution spectrale. Cependant, un nombre important de questions subsiste quant aux agrégats d'hélium dopés, particulièrement, ceux dopés par les alcalino-terreux. En effet, la position d'une impureté au sein de la gouttelette d'hélium est loin d'être un problème trivial pour certaines espèces telles les alcalino-terreux. Ceci est particulièrement vrai dans le cas où l'impureté est l'atome de magnésium. Des preuves expérimentales d'un état solvaté du magnésium sont annoncées dans la littérature tandis que de récentes expériences laissent penser à une position plutôt surfacique du magnésium dans les agrégats d'hélium. Du point de vue théorique, la même ambiguïté persiste quant à la position de Mg dans la nanogoutte d'hélium. Dans le but de contribuer à une meilleure compréhension des clusters d'hélium dopés par les métaux alcalino-terreux (Mg et Ca), nous avons, au cours de ce travail, dû déterminer avec précision les énergies d'interactions des états fondamentaux des systèmes van der Waals CaHe et MgHe. Pour ce faire, des méthodes ab initio telles les approches des clusters couplés (CC) mais aussi perturbationnelles (MP2 et MP4) ont été appliquées à ces deux systèmes avec succès. Les meilleurs potentiels d'interaction ont été utilisés par la suite comme potentiels d'interactions de paire dans l'approche Monte Carlo à diffusion (DMC) en combinaison de deux types de potentiel d'interaction pour l'hélium. Aussi bien pour CaHen que pour MgHen, des simulations DMC ont été produites depuis n = 1 jusqu'à n = 220, le résultat principal en est une position surfacique de l'impureté quelque soit l'alcalino-terreux considéré. Dans le cas particulièrement délicat des clusters d'hélium dopés par le magnésium, des calculs de DMC avec des contraintes géométriques montrent que le potentiel radial effectif de Mg dans He20 et He50 est plutôt plat. Enfin, sont présentés également les résultats concernant la recombinaison dynamique de deux atomes de magnésium à l'intérieur d'un agrégat d'environ 2000 atomes d'hélium utilisant une méthode basée sur un potentiel effectif pour l'interaction He-He

APA, Harvard, Vancouver, ISO, and other styles

5

Guino-o, Marites A. "Placing heavy alkaline earth metals on the map Synthetic access, structure evaluation and reactivity studies of heavy alkaline earth organometallics /." Related electronic resource: Current Research at SU : database of SU dissertations, recent titles available full text, 2008. http://wwwlib.umi.com/cr/syr/main.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Bezougli, Izoldi P. "Insertion reactions of Group 2 metal alkoxides." Thesis, Imperial College London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.484172.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Witherow, Rebecca A. "Minor Alkaline Earth Element and Alkali Metal Behavior in Closed-Basin Lakes." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1250628213.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Caro, Catherine F. "N- and C-centred anionic ligand complexes of the alkaline earth metals." Thesis, University of Sussex, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.263911.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Hill, Matthew Roland Chemistry Faculty of Science UNSW. "The single source chemical vapour deposition of alkaline earth metal oxide thin films." Awarded by:University of New South Wales. School of Chemistry, 2006. http://handle.unsw.edu.au/1959.4/32903.

Full text

Abstract:

Metal oxide thin films are dynamic materials that have revolutionised the nature of semiconductor and electronic thin film devices. Recently, progress has stagnated in some aspects due to the increasingly complex deposition apparatus required, and the dearth of suitable precursor complexes of certain ???difficult??? metals. This thesis seeks to address both of these issues. The application of a precursor complex, Mg6(O2CNEt2)12 to the SSCVD of MgO thin films delivered the highest quality films ever reported with this technique. The resultant films were found to be of purely (111) orientation. Due to the nature of the precursor, the chemical reactions occurring at the surface during SSCVD growth result in a high growth rate, low flux environment and films of (111) orientation have been achieved without the amorphous underlayer. This finding has important implications for buffer layers in perovskite thin film devices. The unprecedented precursor chemistry has been used as a basis for the extremely high quality material produced, along with the unusual, yet beneficial structural morphology it possesses. A new range of barium complexes with single encapsulating ligands have been prepared for use in chemical vapour deposition (CVD) of BaTiO3 thin films. A novel pathway to an unprecedented class of barium carbamates is reported, and also new dianionic bis ??-ketoesterates and their barium, strontium, and calcium analogues were synthesised. High resolution mass spectrometry showed the barium bis ??-ketoesterate derivatives to be monomeric, and preliminary testing indicated some volatility in these species. Insights were gained into the likely successful pathways to building a volatile heterobimetallic precursor complex containing an alkaline earth metal. The knowledge of intimate mixing in heterobimetallic precursor complexes was extended by some novel chemistry to develop the first mixed Zn/Mg carbamato cluster complexes. These complexes were found to be excellent SSCVD precursors for ZnxMg1-xO thin films. Thin films were deposited with these precursors and exhibited a single preferred orientation, with a constant amount of magnesium throughout the bulk of the films. Investigation of the light emission properties of the films revealed significant improvements in the structural order commensurate with the incorporation of magnesium, and the formation of the ZnxMg1-xO alloy.

APA, Harvard, Vancouver, ISO, and other styles

10

Al-Terkawi, Abdal-Azim. "Fluorinated and Fluorine-Free Coordination Polymers Based on Alkaline Earth Metals via Mechanochemistry." Doctoral thesis, Humboldt-Universität zu Berlin, 2018. http://dx.doi.org/10.18452/19246.

Full text

Abstract:

Fluorhaltige-Koordinationspolymere (FCPs) wurden durch mechanochemische Reaktionen synthetisiert. Die Erdalkalimetallhydroxide, die in ihrem Wassergehalt variieren, wurden als anorganische Quellen verwendet. Die perfluorierten Benzol Dicarboxylsäuren und ihre fluorfreien Analoga wurden als organische Linker verwendet. Die erhaltenen FCPs werden mit den fluorfreien Verbindungen (CPs) verglichen, die unter den gleichen Mahlbedingungen synthetisiert wurden. Der Austausch von Wasserstoff- durch Fluoratome beeinflusst sowohl die thermischen als auch die strukturellen Eigenschaften der FCPs. Letztere werden auch von den Unterschieden der Geometrien und von der Natur der organischen Linker beeinflusst. Während des Mahlprozesses dient Wasser dabei hauptsächlich als Vermittlermedium und zur Stabilisierung der neuen Strukturen. Die Unterschiede in den Kationengrößen zwischen Ca2+- und Sr2+-Ionen wirken sich geringfügig auf ihre Koordination durch die Dicarboxylatanionen aus. Hier kristallisieren Ca- und Sr-Verbindungen zumeist isomorph. Im Gegensatz dazu beeinflusst der große Ionenradius der Ba2+-Kationen die lokalen Koordinationsumgebungen. Die durch Mahlen erhaltenen Verbindungen sind hydratisiert und weisen eine kleine spezifische Oberfläche auf, die nach der thermischen Behandlung zunehmen kann. Die FCPs sind bis zu 300 °C stabil, während die CPs sich erst oberhalb von 400 °C zersetzen. Die hydratisierten Proben wandeln sich beim Tempern in neue dehydratisierte Phasen um. Die Phasenumwandlung kann reversible ablaufen. Zusätzlich wurde der Effekt des Austausches einer Carboxylgruppe durch eine Aminogruppe in einem organischen Liganden untersucht. In den CPs auf der Basis von Anthranilsäure beeinflussen die unterschiedlichen Kationengrößen der Ca2+-, Sr2+-, und Ba2+-Ionen sowohl die Koordinationsumgebung als auch die Dimensionalität der CPs.Die physikalisch-chemischen Eigenschaften der neuen Materialien wurden systematisch durch verschiedene analytische Techniken.
A series of fluorinated coordination polymers (FCPs) were mechanochemically synthesized using alkaline earth metal hydroxides (M = Ca, Sr, Ba) that vary in their water content as inorganic sources. The perfluorinated benzene-dicarboxylic acids and their fluorine-free analogs were used as organic linkers. The obtained FCPs are compared to their synthesized fluorine-free counterparts (CPs) under the same conditions. The presence of fluorine influences both thermal and structural properties of the resulting FCPs. The latter are also strongly affected by the difference in geometries and nature of organic linkers. Water introduced to grinding acts as a mediator for the milling process and as a reactant for stabilizing the resulting structures. The difference in cation size between Ca2+- and Sr2+-ions has a minor effect on their coordination with perfluorinated or fluorine free benzene-dicarboxylate anions. Here, Ca- and Sr-compounds crystallize isomorphously (an exception was recorded for ortho-phthalate systems). In contrast, the relatively larger size of Ba2+-cation strongly influences the coordination environment. The obtained compounds by milling are hydrated and exhibit small surface areas that can increase after thermal post-treatment. The FCPs are stable up to 300 ˚C. On the other hand, the nonfluorinated CPs begin to decompose above 400 ˚C. The hydrated samples transform into new dehydrated phases upon thermal annealing. The hydrated-dehydrated phase transformation can be reversible. Moreover, the effect of replacement of one carboxylic group by an amino group in an organic ligand was explored. In the CPs based on anthranilic acid, the variations in cation size between Ca2+-, Sr2+-, and Ba2+-ions affect both coordination environment and dimensionality of the resulting CPs. The physicochemical properties of the new materials were systematically investigated applying different analytical techniques.

APA, Harvard, Vancouver, ISO, and other styles

11

Frankland, Andrew D. "Studies on organic compounds of the group II metals Ca, Sr and Ba." Thesis, University of Sussex, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336274.

Full text

APA, Harvard, Vancouver, ISO, and other styles

12

Roşca, Sorin-Claudiu. "Alkaline-earth complexes supported by fluorinated ancillary ligands." Thesis, Rennes 1, 2015. http://www.theses.fr/2015REN1S155/document.

Full text

Abstract:

L'addition catalysée des amines ou phosphines sur des substrats insaturés (alcènes, alcynes ou allènes) constitue une méthode efficace pour la production d’amines et phosphines à hautes valeurs ajoutées. Pour ces réactions, les complexes hétéroleptiques des métaux alcalino-terreux ont émergé comme des précatalyseurs effi caces. Cette thèse décrit la synthèse de complexes des alcalino-terreux supportés par des ligands aminoalcoolates fluorés de type [{RO}AeN(SiMe2H)2] ({RO} = aminoalcoolate fluoré; Ae = Ca, Sr). Des études par diffraction de rayons X montrent que ces complexes utilisent des interactions Ae···F–C and β-Si–H···Ae pour être cinétiquement inertes. Étonnamment, la somme de ces interactions non-covalentes dites secondaires est prédominante par rapport à la coordination d'éthers sur le centre métallique. En outre, les ligands aminoalcoolates fluorés ont été utilisés pour préparer de rares exemples de complexes Ae hétéroleptiques impliquant la coordination intramoléculaire de donneurs d'électrons π (i.e. alcènes et alcynes). Ainsi, pour la première fois, des complexes Ae stabilisés par des combinaisons d’interactions Ae···Cπ, Ae···F−C et β-Si−H···Ae ont été synthétisés. La nature de ces interactions a été sondée par des moyens spectroscopiques, cristallographiques et calculatoires (DFT). En revanche, nos efforts pour obtenir des complexes Ca–aryles ont conduit à la formation de complexes trinucléaires originaux présentant des interactions secondaires β-Si-H···Ca extrêmement fortes. Certains de ces complexes de calcium ont ensuite été testés en catalyse d’hydrophosphination du styrène avec la diphénylphosphine. Ils ont démontré des activités remarquables (TOF ≈ 50 h−1) en conditions douces, ainsi qu’une régiosélectivité de 100% vers la formation du produit d'addition anti-Markovnikov. En collaboration avec le Pr. M. Etienne et le Dr C. Dinoi du Laboratoire de Chimie de Coordination (Toulouse), un précatalyseur hétéroleptique de calcium supporté par un ligand tris(indazolyl)borate fluoré a été utilisé pour l’hydroamination intramoléculaire du 2,2-diméthylpent-4-en-1-amine, et a fait preuve d’une activité catalytique parmi les plus élevées à ce jour
The catalysed additions of amines or phosphines across unsaturated substrates (alkenes, alkynes or allenes) constitute atom-efficient routes for the production of valuable fine chemicals such as amines and phosphines. For these reactions, heteroleptic alkaline-earth complexes have emerged as promising precatalysts. This PhD thesis describes the synthesis and characterisation of a series of alkaline-earth complexes of type [{RO}AeN(SiMe2H)2] supported by fluorinated aminoalkoxides ({RO} = fluorinated aminoalkoxide; Ae = Ca, Sr ). X-ray diffraction studies show that these complexes heavily involve Ae···F–C and β-Si–H···Ae secondary interactions to achieve kinetic stabilisation. Remarkably, these so-called secondary, non-covalent interactions can be more beneficial towards the stabilisation of the metallic species than the coordination of ethers onto the metal centre. Furthermore, fluorinated aminoalkoxo ligands were used to prepare rare examples of Ae heteroleptic complexes featuring intramolecular coordination from π donors (i.e. alkenes and alkynes). For the first time, Ae complexes stabilised by a combination of Ae···Cπ, Ae···F–C and β-Si–H···Ae interactions were described. The structural and electronic features of these unique complexes were probed by crystallographic, spectroscopic and computational (DFT) methods. The utilisation of aryl-containing ligands resulted in the formation of trinuclear complexes featuring a unique pattern of strong β-Si–H···Ca agostic interactions. Some of these calcium heteroleptic complexes were tested in the hydrophosphination of styrene and HPPh2. They displayed high activities (TOF ≈ 50 h–1) under mild conditions with 100% regioselectivity towards the anti-Markovnikov addition product. In a collaboration with Prof. M. Etienne and Dr. C. Dinoi from the Laboratoire de Chimie de Coordination (Toulouse), a heteroleptic calcium complex supported by a fluorinated tris(indazolyl)borate was used in the intramolecular hydroamination of 2,2-dimethylpent-4-en-1-amine, and it displayed excellent performances

APA, Harvard, Vancouver, ISO, and other styles

13

Sturgeon, Matthew Robert. "Cyanide Bridged Multimetallics Derived From Extended Arrays of Alkaline Earth, Rare Earth, and Transition Metals: A Study From Complexes To Catalysts." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1250009077.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Martin, Johannes [Verfasser], Sjoerd [Akademischer Betreuer] Harder, Sjoerd [Gutachter] Harder, and Ralph [Gutachter] Puchta. "Alkene Activation and Hydrogenation with Alkaline Earth Metals / Johannes Martin ; Gutachter: Sjoerd Harder, Ralph Puchta ; Betreuer: Sjoerd Harder." Erlangen : Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 2021. http://d-nb.info/1233867474/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Soumonni, Ogundiran. "An investigation into the luminescence and structural properties of alkali earth metaniobates." Thesis, Available online, Georgia Institute of Technology, 2004:, 2004. http://etd.gatech.edu/theses/available/etd-05052004-142653/unrestricted/soumonni%5Fogundiran%5F200408%5Fmast.pdf.

Full text

Abstract:

Thesis (M.S.)--School of Materials Science and Engineering, Georgia Institute of Technology, 2005. Directed by Christopher Summers.
Wagner, Brent, Committee Member ; Liu, Meilin, Committee Member ; Gerhardt, Rosario, Committee Member ; Summers, Christopher, Committee Chair. Includes bibliographical references.

APA, Harvard, Vancouver, ISO, and other styles

16

Burgess, Kevin. "Solid-State Nuclear Magnetic Resonance of Exotic Quadrupolar Nuclei as a Direct Probe of Molecular Structure in Organic Ionic Solids." Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/31971.

Full text

Abstract:

In the past decade, the field of NMR spectroscopy has seen the emergence of ever more powerful superconducting magnets, which has opened the door for the observation of many traditionally challenging or non-receptive nuclei. In this dissertation, a variety of ionic solids with organic coordination environments are investigated using quadrupolar solid-state NMR experiments with an ultrahigh-field magnet (21.1 T). Two general research directions are presented including a 79/81Br solid-state NMR study of a series of 6 triphenylphosphonium bromides for which single-crystal X-ray structures are reported herein. A second research direction is also presented wherein alkaline-earth metal (25Mg, 43Ca, and 87Sr) solid-state NMR is used to characterize a systematic series of 16 aryl and alkyl carboxylates. In both studies, the quadrupolar nuclei studied are deemed “exotic” due to their unreceptive nature to NMR spectroscopic analysis including low natural abundances, large quadrupole moments, or low resonance frequencies. A variety of coordination modes to alkaline-earth metals, including N-atom coordination, are characterized herein for the first time using alkaline-earth metal solid-state NMR. In all cases, the electric field gradient (EFG) and chemical shift (CS) tensors are characterized and correlated to structural features such as interatomic distances measured from the crystal structure of the compound under study. In all of the projects undertaken herein, the gauge-including projector-augmented-wave density functional theory (GIPAW DFT) method is used, which allows for the prediction and rationalization of the experimental EFG and CS tensor parameters based on the input crystal structure. In the case of 43Ca solid-state NMR experiments reported in this dissertation, a linear correlation between the calculated and experimental 43Ca quadrupolar coupling constants, CQ, is used as a calibration curve for GIPAW DFT calculations performed on the 18 structural models currently available for the vaterite polymorph of CaCO3. Vaterite cannot be fully characterized by X-ray diffraction alone; therefore an NMR crystallography protocol is used in order to identify the model that best accounts for 43Ca solid-state NMR experiments performed on vaterite. It is expected that the conclusions from this dissertation can be used for future studies involving structural refinement and elucidation of solid materials containing challenging quadrupolar nuclei.

APA, Harvard, Vancouver, ISO, and other styles

17

Ovchinnikov, Alexander [Verfasser], Juri [Akademischer Betreuer] [Gutachter] Grin, Peter [Akademischer Betreuer] Höhn, and Michael [Gutachter] Ruck. "Nitridomanganates of alkaline-earth metals : Synthesis, structure, and physical properties / Alexander Ovchinnikov ; Gutachter: Juri Grin, Michael Ruck ; Juri Grin, Peter Höhn." Dresden : Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://d-nb.info/1122432844/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

Ovchinnikov, Alexander [Verfasser], Juri Akademischer Betreuer] [Gutachter] Grin, Peter [Akademischer Betreuer] Höhn, and Michael [Gutachter] [Ruck. "Nitridomanganates of alkaline-earth metals : Synthesis, structure, and physical properties / Alexander Ovchinnikov ; Gutachter: Juri Grin, Michael Ruck ; Juri Grin, Peter Höhn." Dresden : Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-215891.

Full text

APA, Harvard, Vancouver, ISO, and other styles

19

Stegmaier, Saskia [Verfasser], Thomas F. [Akademischer Betreuer] Fässler, Hubert [Akademischer Betreuer] Schmidbaur, and Karsten [Akademischer Betreuer] Reuter. "Clusters and Networks of Tetrel Elements and Late d Block Metals in Ternary Intermetallic Phases with Alkali and Alkaline Earth Metals / Saskia Stegmaier. Gutachter: Thomas F. Fässler ; Hubert Schmidbaur ; Karsten Reuter. Betreuer: Thomas F. Fässler." München : Universitätsbibliothek der TU München, 2012. http://d-nb.info/1051935032/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

Al-Terkawi, Abdal-Azim [Verfasser], Erhard [Gutachter] Kemnitz, Wolfgang [Gutachter] Tremel, and Gudrun [Gutachter] Scholz. "Fluorinated and Fluorine-Free Coordination Polymers Based on Alkaline Earth Metals via Mechanochemistry / Abdal-Azim Al-Terkawi ; Gutachter: Erhard Kemnitz, Wolfgang Tremel, Gudrun Scholz." Berlin : Humboldt-Universität zu Berlin, 2018. http://d-nb.info/1182541011/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Silva, Mauro Francisco Pinheiro da. "Síntese e caracterização de compostos de adição entre tiocianatos de terras rara e tripiperidinofosfinóxido." Universidade de São Paulo, 2003. http://www.teses.usp.br/teses/disponiveis/46/46134/tde-12032018-144856/.

Full text

Abstract:

Neste trabalho a síntese e caracterizaçcão de adutos entre tiocianatos de terras raras trivalentes (La, Ce Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm Yb, Lu e Y) e tripiperidinofosfinóxidos (tpppO) são reportados. Os adutos foram preparados pela reação entre tiocianatos de lantanídeos e tpppO em soluções etanólicas. Os complexos foram caracterizados por análises elementares, análises termogravimétricas, medidas de condutância em soluções milimolares, espectroscopias de absorção na região do infravermelho, espectroscopia de absorção na região do visível do complexos de neodímio, espectroscopia de emissão na região do visível do composto de európio, térbio e disprósio, difratograma de raios -X pelo método do pó e difratogramas de raios -X pelo método do mono cristal do composto de praseodímio. As análises elementares sugeriram fortemente a fórmula [Ln(SCN)3(tpppO)3] como representativa de toda a série de complexos. As medidas de condutividade de soluções milimolares em acetonitrila resultaram em valores entre 22 e 75 S cm2 mol-1. Esses valores sugeriram a natureza não eletrolítica dos adutos. Os difratogramas pelo método do pó sugeriram a existência de três séries isomorfas, formadas pelos seguintes elementos: 1) La; 2) Ce, Nd, Pr; 3) Sm, Gd, Eu, Ho, Er, To, Lu, Y. Todos os espectros de absorção na região do infravermelho dos adutos são semelhantes e exibem ν(CN)na região de 2050 cm-1.Isso é indicativo da coordenação do ânion a através do átomo de nitrogênio. Os complexos são portanto da classe dos isotiocianatos. Adicionalmente esses pico estão desdobrados em dois picos ( exceto para o Eu e Tb), evidenciando que esses ãnions não são todos equivalentes. Nos espectros de infravermelho observou-se ainda o pico δ(NCS) at ca. 470-480 nm e isso indica também a coordenação através do átomo de nitrogênio. O pico atribuído ao estiramento da ligação PO, ν (PO), está deslocado para regiões menos energética do espectro quando comparado ao espectro do ligante não coordenado. Isso indica a coordenação do tpppO pelo átomo de oxigênio. Nota-se também que os picos ν (PN) apresentando um desvio consistente para regiões mais energéticas para toda a série de complexos sintetizados. O espectro de absorção na região do visível do complexo de neodímio foi registrado e apresentou a banda atribuída á transição 4G5/2, 2G7/2 ← 4I9/2. A banda atribuída à transição 2P1/2 ← 4I9/2 não pode ser observada. A primeira transição foi observada a 17124 cm-1 Desse valor foram calculados: o parâmetro nefelauxético, β = 0,989; o fator de covalência, b 1/2 = 0,072; e o fator de covalência de Sinha δ = 1,06. Esses valores mostram a natureza eletrostática das ligações entre o íon da terra rara e os ligantes. O espectro de emissão do composto de európio, a 77 K, apresenta uma pico atribuído à transição 5D0 →7D0 (578 nm), três picos à 5D0 → 7D1 (593 , 595, 597nm), e cinco à 5D0 → 7D2 (611, 614, 617, 618, 620 nm). Sabendo que a presença do pico 5D0 → 7D0 e os desdobramentos dos picos 5D0 → 7D1 e 5D0 → 7D2 a simetria C3v é a mais provável para o poliedro de coordenação. As análises térmicas foram conduzidas para os complexos de Ce, Nd, Gd. A curva de Tg-DTG mostra perdas de massa começando em 284 -320 ºC e terminando em 1000 ºC. Em 1200 ºC, outra perda de massa ocorre. As curvas, no entanto, mostram algumas diferenças entre si. Enquanto o complexo de cério apresenta cinco eventos não resolvidos entre 300 e 400 ºC, o complexo de Nd apresenta dois eventos não resolvidos e o complexo de Gd apresenta apenas um pico largo na mesma faixa de temperatura. As massas dos resíduos finais de aquecimento (temperaturas maiores que 1300 ºC) são compatíveis com as de fosofatos dos respectivos lantanídeos e o espectro de absorção na região do infravermelho desses resíduos confirmam esses resultados. A análise de difração de raios -X do composto de preseodímio mostrou como sitema critalino o monoclínico, o grupo espacial é o Cc, com quatro moléculas por célula unitária. O Poliedro de coordenação é um prisma trigonal levmente distrocido com simetria de C3V. O número de coordenação é seis com os ânions tiocianatos coordenados pelo nitrogênio, enquanto os os tpppO estão coodenados pelos átomo de hidrogênios.
In this work the synthesis and characterization of trivalent rare earth (La, Ce Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm Yb, Lu and Y) adducts between isothiocyanate with tripiperidinophosphinoxide (tpppO) are reported. The rare earth adducts were prepared by the reaction between lanthanides thiocyanates and tpppO in ethanolic solution. The complexes were characterized by elemental analysis, thermo gravimetric analysis, conductance measurements in millimolar acetonitrila solutions, IR absorption spectroscopy, uv-vis absorption spectrum of the neodymium compound, emission spectrum of europium, dysprosium and terbium compounds, X- ray powder patterns and X-ray diffraction through the monocrystal method of the praseodymium compound. Elemental analyses data strongly suggest the general formula [Ln(SCN)3(tpppO)3] for the complete series. Electrolytic conductivity measurements in milllimolar acetonitrile solutions yielded values in range 75 to 22 S cm2 mole-1. These values suggest the nonelectrolyte natures of the adducts. X-Ray powder diffraction pattern suggest the existence of three isomorphous series: 1) La; 2) Ce, Nd Pr; 3) Sm, Gd, Eu, Ho, Er, Tb, Lu and Y. All absortption spectra in IR region are similar and exhibit ν(CN) in the region of 2050 cm-1. This is indicative that the anion is coordinated through the nitrogen atom, or, in other words, the anion is in the isothiocyanate form. ln addition, these bands are split into two components in all complexes ( except for Eu and Tb ), evidencing that these anions are not all equivalent. In the IR spectra it is also possible to observe δ(NCS) at ca. 470-480 cm-1 and this also point out coordination through the nitrogen atom. In the IR spectra also ν (PO) is shifted to lower energies by ca. 10 cm1 with respect to free tpppO. This indicat coordination through the phosphoryl oxygen. It is also nortworthy that ν (PN) presents a consistent positive shift throghout the whole series of complexes. Absorption spectra of a neodymium compound were recorded. The hypersensitive band 4G5/2, 2G7/2 ← 4I9/2 appears, while the 2P1/2← 4I9/2 could not be observed experimentally. The first transition was observed to be centered at 17124 cm-1. From this value, the nephelauxetic parameter, β = 0,989, covalente factor, bl/2 = 0,072 and Sinha covalence parameter δ = 1,06 were calculated. These value point out the essentially electrostactic nature of metal-ligand bonds. The emission spectra of europium compound at 77 K presents one 5D0 → 7D0 peak (578 nm), three 5D0 → 7D1 peaks (593,595, 597nm) and five for 5D0 → 7D2 band (611,614, 617, 618, 620 nm). Taking into account the presence of 5D0 → 7D0 and the splits of 5D0 → 7D2 and 5D0 → 7D1 peaks the C3v symmetry can be proposed for this coordination polyhedron. Thermal analyses were carried out for Ce, Nd and Gd complexes. Tg-DTG curves show mass lasses starting at 284-320 ºC up to 1000 ºC. At 1200 ºC another mass loss occurs. The curves , however, are quite different whereas the Ce complex shows five non-resolved events between 300 and 400ºC, the Nd adducts shows two non-resolved events and the Gd only a broad peak. The mass of the final residues (above 1300ºC) are consistent with the corresponding lanthanide phosphate. Infrared spectra of these residues were recorded, confirming this assumption. Single- crystal X-ray diffraction analysis of the Pr complex was carried out. The crystal system is the monoclinic, space group Cc, with four molecules per unit cell. The coordination polyhedron is a slightly distorted trigonal antiprism with C3v symmetry. The coordination number is 6. All anion are in the thyocianate form and coordinated through their nitrogen atoms in one base of antiprism whereas the ligand (tpppO) are bonded to the other base through their oxygen atoms.

APA, Harvard, Vancouver, ISO, and other styles

22

Robinson, Alex Lockwood. "Sonoluminescence for the quantitative analysis of alkali and alkaline earth chlorides /." Thesis, Connect to this title online; UW restricted, 2001. http://hdl.handle.net/1773/8687.

Full text

APA, Harvard, Vancouver, ISO, and other styles

23

Köhne, Ingo. "Novel Bulky Bis(benzoxazol-2-yl)methane Ligands in s-Block Metal Coordination." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2018. http://hdl.handle.net/11858/00-1735-0000-002E-E3E8-1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

24

Hossain, A. "Synthesis, crystal structure and properties of complex oxides with the perovskite structure based on neodymium, alkaline earth and 3d-transition metals : dissertation for the degree of candidate of chemical sciences : 02.00.04." Thesis, б. и, 2019. http://hdl.handle.net/10995/82032.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Jones, Sally Anne. "Alkali and alkaline earth metal fluoride mediated aromoatic halogen exchange reactions." Thesis, University of Liverpool, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367085.

Full text

APA, Harvard, Vancouver, ISO, and other styles

26

Blake, Matthew Paul. "Alkaline earth- and rare earth-transition metal complexes." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:d14f9c15-ec66-4317-82df-04d6ba1d4899.

Full text

Abstract:

This Thesis describes the synthesis and characterisation of new alkaline earth- and rare earth-transition metal complexes. Experimental and computational studies were performed to investigate the structure and bonding in these complexes. Their reactivity was also studied. Chapter 1 introduces metal-metal bonded complexes and current alkaline earth- and rare earth-transition metal bonded complexes. Chapter 2 describes experimental and computational studies of new alkaline earth- and lanthanide-Fe complexes possessing the [CpFe(CO)2]- anion. Chapter 3 presents experimental studies of the reduction of Fe3(CO)12 with Ca. Chapter 4 describes experimental and computational studies of new alkaline earth- and lanthanide-Co complexes containing the [Co(CO)3(PR3)]- anion. Chapter 5 presents full experimental procedures and characterising data for the new complexes reported. Appendix describes the attempted synthesis of [Ca{CpRu(CO)2}2(THF)x]y and study by DFT of [CaRp2(THF)3]2 CD Appendix contains .cif files for all new crystallographically characterised complexes described.

APA, Harvard, Vancouver, ISO, and other styles

27

Davidson, Matthew Gwilym. "Alkali and alkaline earth metal complexes of multifunctional amines : syntheses, structures and uses." Thesis, University of Cambridge, 1994. https://www.repository.cam.ac.uk/handle/1810/272659.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Roueindeji, Hanieh. "Métaux alcalino-terreux : chimie de coordination et applications catalytiques." Thesis, Rennes 1, 2020. http://www.theses.fr/2020REN1S032.

Full text

Abstract:

La chimie organométallique des métaux alcalino-terreux (Ae) lourds (Ca, Sr, Ba) est plus difficile que celle de leur analogue plus léger (Mg). Cela est dû à leurs grands rayons ioniques, leur forte électropositivité et leur liaison ionique qui les rendent également très réactifs, sensibles à l'hydrolyse et au brouillage des ligands (c'est-à-dire à l'équilibre de Schlenk). Cette thèse de doctorat décrit la synthèse et la caractérisation de nouvelles familles de complexes Ae stabilisés par des ligands ancillaires et des interactions secondaires, ainsi que l'évaluation de leurs performances dans certaines réactions organiques difficiles catalysées de manière homogène. Une série de complexes homoleptiques et hétéroleptiques Ae supportés par des arylamides fluorés est d'abord présentée. Les études de diffraction des rayons X montrent qu’en plus de la coordination des hétéroatomes, les interactions secondaires inter- et intramoléculaires Ae···F–C remarquablement courtes fournissent une stabilisation cinétique supplémentaire. Des études informatiques complémentaires (DFT) ont révélé que les interactions Ae···F–C sont principalement de nature électrostatique. L'évaluation de certains de ces nouveaux complexes hétéroleptiques de calcium dans la réaction d'hydrophosphination de référence du styrène et de la diphénylphosphine a mis en évidence des activités élevées et une régiospécificité anti-Markovnikov complète dans des conditions douces. La deuxième partie du travail décrit l'étude de nouveaux proligands comportant un bras latéral coordinant éther couronne pour stabiliser les complexes hétéroleptiques de baryum exempts de solvant. Les données structurales aux rayons X et les analyses spectroscopiques RMN montrent un centre métallique hautement coordinné au ligand ancillaire bidenté, en plus des contacts avec les hétéroatomes du bras latéral, ce qui conduit à des complexes Ba encapsulés combinés avec des interactions secondaires β-Si–H···Ae. Ces complexes originaux ont montré des résultats gratifiants dans les réactions d'hydrophosphination
The organometallic chemistry of heavy alkaline-earth metals (Ae = Ca, Sr, Ba) is more challenging than that of their lighter analogue (Mg). This is due to their large ionic radii, strong electropositivity and ionic bonding which also make them highly reactive, sensitive to hydrolysis and to ligand scrambling (i.e. to Schlenk equilibrium). This PhD thesis describes the synthesis and characterization of new families of Ae complexes stabilized by ancillary ligands and secondary interactions, along with the evaluation of their performances in some challenging homogeneously-catalyzed organic reactions.A series of homoleptic and heteroleptic Ae complexes supported by fluorinated arylamides is first presented. X-ray diffraction studies show that beside the coordination of the heteroatoms, remarkably short inter- and intramolecular Ae···F–C secondary interactions provide additional kinetic stabilization.Complementing computational (DFT) studies revealed that Ae···F–C interactions are mostly electrostatic in nature. Evaluation of some of these new calcium heteroleptic complexes in the benchmark hydrophosphination reaction of styrene and diphenylphosphine evidenced high activities and full anti-Markovnikov regiospecificity under mild conditions. The second part of the work describes the study of new proligands featuring a coordinating tethered crown-ether side arm to stabilize solvent-free barium heteroleptic complexes. X-ray structural data and NMR spectroscopic analyses support the highly coordinated metal center to the bidentate ancillary ligand including contacts with the side-arm heteroatoms resulting in encapsulated Ba complexes combined with β-Si–H···Ae secondary interactions. These original complexes showed rewarding results in hydrophosphination reactions

APA, Harvard, Vancouver, ISO, and other styles

29

Rees, David Alan. "Synthesis of alkaline earth transition metal sulfides." Thesis, University of Nottingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311775.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Murgia, Fabrizio. "Eléments du block p comme matériaux d'électrode négative pour accumulateurs Magnésium-ion : mécanismes électrochimiques et performances." Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTT210/document.

Full text

Abstract:

Parmi les défis que le Monde devra affronter dans les prochaines décennies, le plus difficile est l’utilisation d’énergie durable. Dans un scénario où les sociétés occidentales sont fortement dépendantes des combustibles fossiles pour garder leur niveau de bien-être (chauffage domestique, transport et production d’électricité), complété par les pays en voie de développement qui ont besoin d’alimenter leurs économies croissantes, il est nécessaire de souligner l’impact négatif sur l’environnement causé par l’utilisation de ces ressources fossiles mais aussi les problèmes géopolitiques pour les pays « non producteurs ». La collecte d’énergie provenant des sources renouvelables peut limiter la dépendance des combustibles fossiles, pourtant cette dernière ne peut remplacer les centrales électriques classiques à cause de son caractère intermittent.Les batteries sont des dispositifs qui peuvent résoudre définitivement cette limitation, puisqu’elles sont capables d’accumuler l’excès d’énergie produit afin de le délivrer au moment souhaité. De plus elles ont été envisagées comme les dispositifs principaux pour toutes les applications portables (téléphones et ordinateurs portables mais aussi véhicules). Grâces à ses excellentes performances et sa technologie bien développée, les batteries lithium-ion ont un rôle déterminant dans le support de cette nouvelle révolution énergétique. Pourtant leur usage répandu a été récemment remis en question à cause de la faible disponibilité de lithium, qui est un élément rare et concentré seulement dans certaines zones du monde. L’emploie du lithium pourrait donc engendrer les mêmes problèmes que les combustibles fossiles. De plus, cette technologie semble avoir atteint son niveau de développement maximal et ne pourrait plus être suffisante pour satisfaire des applications de plus en plus énergivores. Il est donc nécessaire d’envisager des alternatives au lithium en axant les recherches sur des ressources plus abondantes que lithium et à moindre coût mais aussi sur des systèmes plus performantes.Les batteries post-lithium, qui sont basées sur d’autres porteur de charges que le Li+, pourrait représenter des alternatives plus sécurisées, respectueuse de l'environnement et aussi plus attractifs en termes de capacité stockée. Le magnésium est un candidat prometteur pouvant remplacer le lithium dans les systèmes électrochimiques de stockage d’énergie, grâce à son abondance, son faible coût et sa capacité volumique qui est doublée par rapport à cette du lithium. Cependant, l’obstacle le plus important au développement des batteries rechargeable au magnésium est la mauvaise compatibilité entre les électrolytes classiques et le magnésium métal. Dans cette optique il est encore nécessaire d’utiliser des mélanges de sel/solvant extrêmement dangereux dans les prototypes proposés. En revanche, la recherche de possible alternatives au magnésium métal, c.-à-d. des matériaux capable de réagir à bas potentiel avec le Mg, permettrait de réaliser une véritable batterie aux ions de magnésium (MIB), compatible avec des formulations d’électrolyte classiques.Cette thèse est dédiée à l’investigation des comportements électrochimiques de plusieurs éléments du bloc p (In, Sn, Sb, Bi) qui peuvent s’allier réversiblement avec le Mg à bas potentiel. Des possibles synergies entre ces éléments ont été aussi explorées (composite Sn-Bi, phases intermétalliques BixSb1-x et InBi) qui puissent être employés comme électrodes négatives pour MIBs. Des poudres micrométriques ont été obtenues par broyage/alliage mécanique, technique de synthèse simple à mettre en œuvre. Une attention particulière a été portée à l’étude des mécanismes électrochimiques d’alliage et/ou conversion avec la diffraction des rayons X en mode operando. L’évaluation des performances électrochimiques a permis de sélectionner le meilleur candidat pour être testé comme électrode négative dans un prototype de batterie magnésium-ion
One of the most challenging hurdles that the World has to face in the next decades is the sustainable use of energy. In a scenario where western societies are largely dependent of the fossil fuels for maintaining their wellness, i.e. for heating, automotive transportation and electricity production, and developing countries need to feed their growing economies, it is worth underlying both the major impact on the environment due to the indiscriminate use of such combustibles but also the geopolitical issues for the non-producing countries. Energy harvesting by renewable sources can help limiting the dependence on fossil fuel exploitation but cannot perfectly replace conventional power plant due to its intrinsic intermittency.Batteries are the devices that can draw a line under this situation, since they can stock the energy surplus when the plant is operating and then can squeeze it in the power grid when there is a lack of production. Moreover, they are also targeted to fulfil the even growing demand of energy for portable applications (mobile phones and computers, and nowadays cars and trucks). The excellent performance and the well-established technology of Lithium-ion batteries (LIBs) put them in a crucial position for supporting this new energy revolution. However their ubiquitous role has been recently questioned for two main reasons: i) of the low availability of Li, which is a rare and not-uniformly spread element that may lead to the similar problems caused by fossil fuels. And ii) the effective capacity to satisfy the highly energy-demanding applications, since Li-ion technology seems reaching is upper limit in terms of overall performance. Therefore cheaper and more powerful alternative to Li-based systems are needed.Post-Lithium-based batteries, based on other charge carriers than Li+ can be offer safer, more sustainable and performing alternative to LIBs. Mg is a promising candidate that can replace Li in electrochemical systems due to its abundance, low cost and a theoretical volume capacity twice higher than that of Li. Although the efforts devoted to the realization of a rechargeable Mg battery were made in the last 15 years, the major hurdle represented by the low compatibility between metallic Mg and conventional electrolytes still obliges the use of hazardous salt/solvent mixtures in research prototypes. Searching alternative negative electrodes to the Mg metal, i.e. compounds able to reversibly react with Mg at low potential, will pave the way for a veritable Magnesium-ion battery (MIB), allowing the use of conventional electrolytes.The present thesis is devoted to investigate the electrochemical behaviour of several p-block elements that can reversibly alloy with Mg at low potential (In, Sn, Sb, Bi). Possible synergies between these elements are also explored, realizing composite materials (Sn-Bi), or intermetallic phases (BixSb1-x and InBi) that could be employed as negative electrodes in MIBs. The chosen synthetic route for obtaining micrometric-sized particles is the mechanical milling/alloying, since it is simple, cost-effective and upscalable. Particular attention is put on the study of electrochemical mechanisms through the operando X-ray diffraction. Electrochemical performance evaluation allows selecting the best candidate for an effective test as negative electrode in MIB prototype

APA, Harvard, Vancouver, ISO, and other styles

31

Chen, Chun-che. "Correlation between electrical and magnetic properties in alkali and alkaline earth metal doped lanthanum manganites /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Liang, Tao. "Chiral Phosphoric Acids and Alkaline Earth Metal Phosphates Chemistry." Thesis, University of South Florida, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3632228.

Full text

Abstract:

Asymmetric synthesis and catalysis is one of the leading research areas in chemistry society, for its versatility and efficiency in obtaining chiral molecules that found the vast majority in natural active compounds and synthetic drugs. Developing asymmetric catalytic methodology is at the frontier in both industrial and academic research laboratories. Enantioselective organocatalysis has emerged as a powerful synthetic tool that is complementary to metal-catalyzed transformations. The development of chiral phosphoric acid and metal phosphate as catalysts has been a breakthrough in recent years. Chiral phosphoric acids have been shown to be powerful catalysts in many organic transformations. Moreover, chiral metal phosphates, which formed by simply replacing the proton in phosphoric acid with metals, have introduced new catalytic activations and broaden the scope of phosphoric acids. This thesis details new highly enantioselective chiral phosphoric acid-catalyzed Pinacol rearrangement and robust alkaline phosphates catalytic system, which utilizes novel carbonyl activation.

The Pinacol rearrangement has long been known to be difficult to control in terms of regioselectivity and stereoselectivity. The initial studies found that indolyl-diol compounds can be treated with chiral phosphoric acids to afford the Pinacol rearrangement with high regio- and enantioselectivity. Over 16 chiral phosphoric acids were screened, and it was found an H8-BINOL-phosphoric acid variant with 1-naphthyl groups at 3 and 3' position was the excellent catalyst. This asymmetric transformation is tolerant toward variety of substituents both on the indole ring and migrating groups.

During the study, it was found that different ways to generate the catalyst had critical effect on this catalytic transformation. Only those phosphoric acids washed with HCl after column chromatography afforded the rearrangement products with high enantioselectivity. And those without treating with HCl were found contaminated by alkaline metals. These "contamination" catalysts were also found active with carbonyl activations.

A highly enantioselective catalytic hetero-Diels-Alder reaction of alpha-keto esters has been developed with chiral alkaline metal phosphates. A calcium 1-naphthyl-BINOL phosphate was found to be the optimum catalyst. A large range of alpha-keto esters as well as isatins can be applied in this alkaline phosphates catalytic system with high efficiency and selectivity. The structure of the catalyst is detailed for the first time by X-ray crystal structure analysis. A proposed Transition state model is provided based on the catalyst crystal structure and Raman spectroscopy analysis.

This methodology was further developed with an asymmetric Mukaiyama-Michael addition of beta,gamma-unsaturated alpha-keto ester. The best catalyst was found to be a magnesium chiral phosphate. And the transformation was found capable of tolerating a wide variety of beta,gamma-unsaturated alpha-keto esters.

APA, Harvard, Vancouver, ISO, and other styles

33

Hamdy, Louise. "Developing new hydrogen bonded alkaline earth metal-organic complexes." Thesis, University of Bath, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.675739.

Full text

Abstract:

This investigation addresses the understudied area of the research and development of hydrogen bonded metal-organic complexes featuring the alkaline earth metals magnesium and calcium. This work presents the crystal structures and thermal behaviour of a series of metal-organic and organic crystalline complexes synthesised from metal salts and pyridine carboxylic, dicarboxylic acid and chloranilic acid ligands, characterised primarily by X-ray diffraction. Chapter 1 introduces crystal engineering, intermolecular interactions, and functional crystalline materials, followed by a literature review addressing metal-organic frameworks (MOFs), hydrogen bonded metal-organic complexes, magnesium MOFs and alkaline earth metal complexes synthesised from pyridine carboxylic, dicarboxylic and tricarboxylic acid and chloranilic acid. Chapter 2 outlines the theory of the techniques used to analyse the synthesised materials, focusing on single crystal X-ray diffraction, followed by Chapter 3 which documents the sample preparation and the experimental details. Chapter 4 describes the crystal structures of fourteen coordination complexes synthesised from magnesium and calcium salts and the three isomers of pyridine carboxylic acid. This work was carried out in order to identify structural trends such as the most common coordination geometries of the metal centres, the ways in which the ligands coordinate and any recurring hydrogen bonding motifs. Chapter 5 discusses attempts to synthesise an alkaline earth metal analogue of a metal-containing ‘metalloligand’ of the formula M(C7H4NO4)2(H2O)2, in which the metal (M) is N,O-chelated by pyridine-2-carboxylate-4-carboxylic acid, and the subsequent combination of these materials with the diamines o-tolidine and m-xylylenediamine. This chapter also reports the structure of a magnesium coordination complex resulting from a hydrothermal reaction, and the subsequent transformation of this complex to a new crystal structure which contains the doubly deprotonated magnesium analogue of the originally targeted ‘metalloligand’. Chapter 6 describes the crystal structures of three complexes synthesised from pyridine carboxylic acids and chloranilic acid, and the complex resulting from the combination of one of these organic ‘supramolecular ligands’ with a copper salt. Finally, two new calcium-chloranilate coordination polymers are reported, one of which has an interesting anionic 3D structure.

APA, Harvard, Vancouver, ISO, and other styles

34

Gillett-Kunnath, Miriam M. "Heavy alkaline earth metal amides: Synthetic and structural investigations." Related electronic resource: Current Research at SU : database of SU dissertations, recent titles available full text, 2008. http://wwwlib.umi.com/cr/syr/main.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

Hitzbleck, Julia Ruhlandt-Senge Karin. "Syntheses and structural survey of novel alkaline earth and rare earth metal complexes." Related electronic resource: Current Research at SU : database of SU dissertations, recent titles available full text, 2004. http://wwwlib.umi.com/cr/syr/main.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

Sánchez, José Adán Reyes. "Synthesis and reactivity of alkaline earth and aluminium gallyl complexes." Thesis, University of Oxford, 2018. http://ora.ox.ac.uk/objects/uuid:5bf3dc4e-9cd6-4080-8f5f-9097e84ba12b.

Full text

Abstract:

This Thesis describes the synthesis and characterisation of new alkaline earth metal and aluminium gallyl complexes. Experimental studies were performed to investigate their structure. The reactivity of these species was also studied. Chapter 1 introduces metal-metal bonded complexes containing alkaline earth metals and aluminium and the use of gallium(I) analogues of N-heterocyclic carbenes in the synthesis of heterobimetallic complexes of gallium. Chapter 2 describes the synthesis and reactivity of alkaline earth gallyl complexes supported by beta-diketiminate ligands. Chapter 3 presents the synthesis and reactivity of alkaline earth gallyl complexes supported by the carbazolide ligand CzOx. Chapter 4 describes synthesis of aluminium-gallium bonded complexes supported by amidinate and b-diketiminate ligands and the attempted study of their reactivity. Chapter 5 presents full experimental procedures and characterising data for the new complexes reported.

APA, Harvard, Vancouver, ISO, and other styles

37

Vargas, Gregory Wilda Ruhlandt-Senge Karin. "Nitrogen-based alkaline earth metal compounds syntheses, structures and applications /." Related electronic resource: Current Research at SU : database of SU dissertations, recent titles available full text, 2004. http://wwwlib.umi.com/cr/syr/main.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Reid, Stephanie. "Heavier alkaline earth metal catalysis and application to organic synthesis." Thesis, Imperial College London, 2015. http://hdl.handle.net/10044/1/61488.

Full text

Abstract:

This thesis describes the application of complexes of heavier alkaline earth metals to the intramolecular hydroalkoxylation/cyclisation of alkynyl and allenyl alcohols and in addition, to the hydroamination of polyunsaturated arenes. Cyclisation of alkynyl alcohols was achieved using [Ae{N(SiMe3)2}2] (Ae = Ca, Sr, Ba) in the formation of five- and six-membered enol ethers. The cyclisations produced mixtures of the possible endo- and exocyclic enol ether products, rationalised as a consequence of alkyne/allene isomerisation. Although a ‘catalyst of choice’ could not be deduced, [Ba{N(SiMe3)2}2] proved highly effective in these cyclisations. Extension of the hydroalkoxylation towards tandem C−O/C−C formation was attempted with dialkynyl alcohols but in all cases led to monocyclisation of the substrates. Catalytic tandem C−N bond-forming reactions have been successfully applied to the double hydroamination of polyunsaturated arenes using heteroleptic complexes of the type [LAe{N(SiMe3)2}(THF)n] (Ae = Ca, Sr, Ba). Chemo- and regioselective hydroamination reactions are coupled in sequence to construct tetrahydroisoquinoline frameworks. The amine scope of these reactions was determined and results have shown that these regioselective transformations occur under significant stereoelectronic control.

APA, Harvard, Vancouver, ISO, and other styles

39

Bradwell, David (David Johnathon). "Liquid metal batteries : ambipolar electrolysis and alkaline earth electroalloying cells." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/62741.

Full text

Abstract:

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2011.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 198-206).
Three novel forms of liquid metal batteries were conceived, studied, and operated, and their suitability for grid-scale energy storage applications was evaluated. A ZnlITe ambipolar electrolysis cell comprising ZnTe dissolved in molten ZnCl 2 at 500 0C was first investigated by two- and three-electrode electrochemical analysis techniques. The electrochemical behavior of the melt, thermodynamic properties, and kinetic properties were evaluated. A single cell battery was constructed, demonstrating for the first time the simultaneous extraction of two different liquid metals onto electrodes of opposite polarity. Although a low open circuit voltage and high material costs make this approach unsuitable for the intended application, it was found that this electrochemical phenomenon could be utilized in a new recycling process for bimetallic semiconductors. A second type of liquid metal battery was investigated that utilized the potential difference generated by metal alloys of different compositions. MgjlSb cells of this nature were operated at 700 °C, demonstrating that liquid Sb can serve as a positive electrode. Ca,MgIIBi cells also of this nature were studied and a Ca,Mg liquid alloy was successfully used as the negative electrode, permitting the use of Ca as the electroactive species. Thermodynamic and battery performance results suggest that Ca,MgIISb cells have the potential to achieve a sufficient cell voltage, utilize earth abundant materials, and meet the demanding cost and cycle-life requirements for use in grid-scale energy storage applications.
by David J. Bradwell.
Ph.D.

APA, Harvard, Vancouver, ISO, and other styles

40

Kumar, R. "Synthesis and molecular catalysis with organo- alkaline earth metal complexes." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2022. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/6167.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Nimmagadda, Sri Krishna. "Asymmetric Transformations Catalyzed By Chiral BINOL Alkaline Earth Metal Phosphate Complexes." Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6554.

Full text

Abstract:

Small molecule hydrogen bond donors have emerged as versatile catalysts in asymmetric synthesis. Within this class, chiral BINOL phosphoric acid is regarded as one of the pioneer catalysts used in several asymmetric transformations. The ability of the catalyst to activate the substrates could be controlled in two different ways. (1) Dual activation/bifunctional activation of substrate by hydrogen bond interactions or ion pairing with phosphoric acid or (2) By forming chiral BINOL phosphate metal complex that could significantly alter the interactions in chiral space. In particular, chiral alkaline earth metal phosphate complexes have unique advantages as catalysts owing to the ubiquitous availability of alkaline earth metals, strong Brønsted basicity of their counterions, mild but significant Lewis acidity of the metal and their ability to coordinate at multiple reactive sites due to large ionic radius. Chapter 1 summarizes the recent development of alkaline earth metal complexes in asymmetric catalysis. My thesis dissertation is focused on the application of chiral alkaline earth metal phosphate complexes in novel asymmetric reactions. In Chapter 2, we disclosed an efficient asymmetric one-pot synthesis of chiral 1,3-oxazolidines and chiral 1,3-oxazinanes. Chiral oxazolidines and oxazinanes are widely used as auxiliaries in asymmetric transition metal catalysis and also key structural motifs in natural products with biological activities. We developed a new synthetic method for chiral 1,3-oxazolidines which follows the enantioselective addition of alcohols to imines catalyzed by chiral 3,3’-(triisopropylphenyl)-derived BINOL magnesium phosphate to form hemiaminal intermediate, which then undergoes mild base mediated intramolecular nucleophilic substitution to afford highly enantioselective 1,3-oxazolidines and 1,3-oxazinanes in good yields. In Chapter 3, we developed the first catalytic enantioselective desymmetrization process for the synthesis of novel axially chiral cyclohexylidene oxime ethers. Even though these molecules were found to be optically active in 1910, methods to synthesize these molecules are scarce. We have developed an efficient desymmetrization process of 4-phenyl cyclohexanones with phenoxyamines catalyzed by chiral BINOL strontium phosphate complex to afford highly enantioselective products. We then extended this methodology to the dynamic kinetic resolution of 2-substituted cyclohexanones to form chiral 2-substituted cyclohexyl oximes in good enantioselectivities, as demonstrated in Chapter 4. We further demonstrated the utility of these compounds by converting them to chiral 2-aryl cyclohexylamines which are important synthetic intermediates.

APA, Harvard, Vancouver, ISO, and other styles

42

Potratz, Christopher M. "The Synthesis, Structure and Characterization of Extended Cobalt Ruthenium Carbonyl Compounds." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1275413923.

Full text

APA, Harvard, Vancouver, ISO, and other styles

43

Santoru, Antonio [Verfasser]. "Insights into the structure and reaction mechanism of alkali and alkaline-earth metal amide-metal hydride composite systems for hydrogen storage / Antonio Santoru." Hamburg : Helmut-Schmidt-Universität, Bibliothek, 2018. http://d-nb.info/1162510706/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

44

Demydov, Dmytro V. "Nanosized alkaline earth metal titanates : effects of size on photocatalytic and dielectric properties." Diss., Manhattan, Kan. : Kansas State University, 2006. http://hdl.handle.net/2097/177.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Diteepeng, Nichabhat. "Alkaline earth hydroborate complexes for the ring-opening polymerisation of cyclic esters." Thesis, University of Oxford, 2018. http://ora.ox.ac.uk/objects/uuid:d5b45f1c-b8a9-41da-a967-7f569b69aa35.

Full text

Abstract:

This Thesis describes the activity and mechanism of alkaline earth organohydroborate, tetrahydroborate and alkoxide catalysts for the ring-opening polymerisation (ROP) of cyclic esters including rac-, L-, D- and meso-lactide (LA), and rac-β-butyrolactone (rac-BBL). Chapter One introduces cyclic esters and general mechanisms for their ROP to give polyesters. Living and immortal ROP, an overview of stereocontrolled ROP, and determination of polylactide (PLA) stereosequences are given. Various techniques for polymer characterisations are also described. Chapter Two describes the activity and mechanism of heavy alkaline earth organohydroborate complexes for the ROP of LA. The synthesis and characterisation of alkaline earth alkoxide complexes serving as model species are also described, together with their activities for the ROP of LA. Chapter Three describes the activity and mechanism of a cyclic organohydroborate calcium complex for the ROP of LA. The role of borinic esters as chain transfer agents in the ROP of rac-LA is also discussed. Chapter Four describes the activity and mechanism of heavy alkaline earth tetrahydroborate complexes for the ROP of LA. The immortal ROP of rac-LA using heavy alkaline earth alkoxide complexes and borate esters as chain transfer agents is discussed. Chapter Five describes the activity and mechanism of alkaline earth organohydroborate, tetrahydroborate and alkoxide complexes for the ROP of rac-BBL. Chapter Six presents experimental procedures and characterising data for new complexes reported.

APA, Harvard, Vancouver, ISO, and other styles

46

Teng, Weijie Ruhlandt-Senge Karin. "From polymerization initiators to precursors for solid-state materials syntheses and structures of a series of molecular alkali and alkaline earth metal derivatives /." Related electronic resource: Current Research at SU : database of SU dissertations, recent titles available full text, 2004. http://wwwlib.umi.com/cr/syr/main.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Yadav, S. "Preparation of well-defined alkaline earth metal complexes and their applications in molecular catalysis." Thesis(Ph.D.), CSIR National Chemical Laboratory, Pune, 2019. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/4572.

Full text

APA, Harvard, Vancouver, ISO, and other styles

48

Tulyapitak, Tulyapong. "CURE AND MECHANICAL PROPERTIES OF CARBOXYLATED NITRILE RUBBER (XNBR) VULCANIZED BY ALKALINE EARTH METAL COMPOUNDS." University of Akron / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=akron1158067153.

Full text

APA, Harvard, Vancouver, ISO, and other styles

49

Fleming, Kathleen. "The Gas-Phase Ligand Exchange of Select Alkaline Earth and Transition Metal ß-diketonate Complexes." Youngstown State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1465062889.

Full text

APA, Harvard, Vancouver, ISO, and other styles

50

Zuniga, Maria Felisa A. "Progress in molecular heterobimetallic alkaline earth metal chemistry New synthetic strategies, structural features and properties /." Related electronic resource: Current Research at SU : database of SU dissertations, recent titles available full text, 2008. http://wwwlib.umi.com/cr/syr/main.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Dissertations / Theses on the topic 'Alkaline earth metals'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles