No description available.

This work began with the synthesis and full characterization of a novel £^-diimine ligand, (2,6-iPr2C6H3N=CH)2C6H4, from the reaction of o-phthaladehyde and the bulky aniline, 2,6-diisopropylaniline. It was observed that any <i>di-ortho</i>-substituted aniline with less bulky groups than isopropyl groups resulted in formation of the corresponding iminisoindolines. Reaction of the £^-diimine ligand with PdCl2 did not result in a seven-membered coordination complex, but in non-palladacyclic complex, [(g-diimine)PdCl(Ý-Cl)]2. Whereas reaction with Pd(OAc)2 gave an S-shaped five-membered trinuclear palladacyclic complex, {1,2-(2,6-iPr2-C6H3N=CH)2-C6H3]Pd(Ý-OAc)2}2Pd. These complexes were found to be active precatalysts for Heck and Suzuki coupling reaction giving TONs of up to 104 and 86, for arylbromides and arylchlorides, respectively.<p> On the other hand, a series of neutral and cationic seven-membered aluminum coordination complexes were obtained from the reaction of £^-diimine with a variety of aluminum species (AlMe3, AlMe2Cl, AlMeCl2 and AlCl3). The synthesis and characterization of these complexes are exemplified.<p> Also illustrated in this thesis is the synthesis and characterization of a series of air- and moisture-stable iminoisoindoline-based palladacyclic compounds of the general formula, [(iminoisoindoline)Pd{Ý-OAc}]2. These six-membered palladacyclic complexes were obtained through a simple two-step protocol as analytically pure solids. Phosphine-ligated mononuclear palladacycles of the general formula, [Pd(iminoisoindoline)X(PR3)], X= OAc or Cl, R = Ph or Cy, are also described. Dinuclear palladacycles were also found to be active for the Heck and Suzuki C-C coupling reactions. TONs of up to 106, 105 and 60 were observed for coupling of iodobenzene, <i>p</i>-acetylbromobenzene and <i>p</i>-chlorobenzaldehyde, respectively in the Heck coupling reaction.

This work began with the synthesis and full characterization of a novel £^-diimine ligand, (2,6-iPr2C6H3N=CH)2C6H4, from the reaction of o-phthaladehyde and the bulky aniline, 2,6-diisopropylaniline. It was observed that any <i>di-ortho</i>-substituted aniline with less bulky groups than isopropyl groups resulted in formation of the corresponding iminisoindolines. Reaction of the £^-diimine ligand with PdCl2 did not result in a seven-membered coordination complex, but in non-palladacyclic complex, [(g-diimine)PdCl(Ý-Cl)]2. Whereas reaction with Pd(OAc)2 gave an S-shaped five-membered trinuclear palladacyclic complex, {1,2-(2,6-iPr2-C6H3N=CH)2-C6H3]Pd(Ý-OAc)2}2Pd. These complexes were found to be active precatalysts for Heck and Suzuki coupling reaction giving TONs of up to 104 and 86, for arylbromides and arylchlorides, respectively.<p> On the other hand, a series of neutral and cationic seven-membered aluminum coordination complexes were obtained from the reaction of £^-diimine with a variety of aluminum species (AlMe3, AlMe2Cl, AlMeCl2 and AlCl3). The synthesis and characterization of these complexes are exemplified.<p> Also illustrated in this thesis is the synthesis and characterization of a series of air- and moisture-stable iminoisoindoline-based palladacyclic compounds of the general formula, [(iminoisoindoline)Pd{Ý-OAc}]2. These six-membered palladacyclic complexes were obtained through a simple two-step protocol as analytically pure solids. Phosphine-ligated mononuclear palladacycles of the general formula, [Pd(iminoisoindoline)X(PR3)], X= OAc or Cl, R = Ph or Cy, are also described. Dinuclear palladacycles were also found to be active for the Heck and Suzuki C-C coupling reactions. TONs of up to 106, 105 and 60 were observed for coupling of iodobenzene, <i>p</i>-acetylbromobenzene and <i>p</i>-chlorobenzaldehyde, respectively in the Heck coupling reaction.

Research into inorganic supramolecular chemistry is burgeoning, in particular that which focuses on the formation of capsular molecules and the effects that these unique environments have on catalytic reactions. With the aim of producing new ligand designs that could not only support reactive metals, but also partake in supramolecular aggregation to provide a capsular microenvironment, new tripodal ligands and wide span imines and amines have been synthesised. Furthermore, the exploitation of hydrogen-bonding motifs formed through pyrrole-imine tautomerisation upon metallation of these ligands has been explored, with the aim of enhancing reactivity and stabilising reactive intermediates. In Chapter one, the concept of covalent and non-covalent capsules is introduced, and includes the different aspects affecting the encapsulation of molecules and their use as nanoreactors. The use of secondary interactions, e.g. hydrogen-bonding in metal complexes of tetrapodal and tripodal ligands is discussed. Chapter two describes the synthesis of a tripodal pyrrole-imine ligand and the formation of its multi-metallic complexes of Group one metals, transition metal and the f-block elements. The complete and partial tautomerisation of this ligand upon metal complexation is also examined. In Chapter three, the formation of hangman complexes of the tripodal pyrrole-imine ligand is described and is extrapolated to the chemistry of a new pyrrole-amide ligand. The synthesis of this latter ligand and its properties with regards to anion binding are also explored. Chapter four describes the formation of wide span diamine and diimine ligands and their propensity to form adducts with cobalt and zinc chlorometallates and unusual multimetallic palladium complexes. The final conclusions of the work presented in this thesis are drawn in Chapter five. Chapter six presents experimental details and characterising data for all of the new compounds presented in this thesis.

The chloro and pyridinate derivatives of rhenium(I) tricarbonyl complexes containing the diimine ligands 2,2’-bipyrazine (bpz) and 5,5’-dimethyl-2,2’-bipyrazine (Me2bpz) are discussed. When compared to similar rhenium(I) tricarbonyl complexes of 2,2’-bipyridine (bpy) and 2,2’-bipyrimidine (bpm), the Me2bpz complexes are comparable to bpm derivatives and their properties are intermediate between those of bpy and bpz complexes. Also discussed is the synthesis and properties of two new analogues of ruthenium(II) tris-bipyridine, a monomer and dimer. The complexes contain the ligand 6,6’-(1,2-ethanediyl)bis-2,2’-bipyridine (O-bpy) which contains two bipyridine units bridged in the 6,6’ positions by an ethylene group. Crystal structures of the two complexes formulated as [Ru(bpy)(O-bpy)](PF6)2 and [(Ru(bpy)2)2(O-bpy)](PF6)4 reveal structures of lower symmetry than D3 which affects the electronic properties of the complexes as revealed by Density Functional Theory (DFT) and Time Dependent Density Functional Theory (TDDFT) calculations. Iron(II) tris-bipyrazine undergoes dissociation in solution with loss of the three bipyrazine ligands. The rate of the reaction in acetonitrile depends on the concentration of anions present in the solution. The rate is fastest in the presence of Cl- and slowest in the presence of Br-. In a second discussion DFT calculations are used to explore four iron(II) diimine complexes. DFT calculations show the higher energy HOMO (highest occupied molecular orbital) orbitals of the four complexes are metal centered and the lower energy LUMO (lowest unoccupied molecular orbitals) are ligand centered. / Dissertation(Ph.D.)--Wichita State University, College of Liberal Arts and Sciences, Dept. of Chemistry

none

The synthesis, structure, and reactivity of titanium bis(diimine) complexes supported by 1,2-alternate dimethylsilyl-bridged p-tert-butylcalix[4]arene dianion and 2,2' methylene-bridged 4-methyl, 6-tertbutyl phenol ligands is reported. The molecular structure of [(DMSC)Ti(bpy)2] (28) and [(MBMP)Ti(bpy)2] (55) was characterized by X-ray crystallography. Complexes [(DMSC)Ti(bpy)2] (28), [(DMSC)Ti(dmbpy)2] (29), and [(DMSC)Ti(phen)2] (30) undergoes light-assisted reactions with two or more equivalents of (C6H5)2CO or (p-MeC6H4)2CO to give the corresponding 1-aza-5-oxa-titanacyclopentene complexes 37-42. Similar reactivity was observed with [(MBMP)Ti(bpy)2] (55), [(MBMP)Ti(dmbpy)2] (56), and [(MBMP)Ti(phen)2] (57). The molecular structure of [(MBMP)Ti{kappa-3-OC(C6H5)2C10H7N2}{OCH(C6H5)2}] (58) was characterized by 1H and 13C NMR as well as X-Ray crystallography.

A plethora of novel scientific phenomena and practical applications, such as solid-state molecular solar cells and other optoelectronic devices for energy harvesting and lighting technologies, have catalyzed us to synthesize novel compounds with tunable properties. Synthetic routes, single crystal structures, and spectral and materials properties are described. Reactions of Ag(I) and Cu(I) precursors with various types of ligands -- including the azolates, diimines, and diiphosphines -- lead to the corresponding complexes in high yield. Varying the metal ions, ligands, synthetic methods, solvents, and/or stoichiometric ratio can change the properties including the molecular geometry or packing structure, reactivity, photophysical and photochemical properties, semiconducting behavior, and/or porosity of the functional coordination polymers obtained. For solar cells purposes, the absorption energy can be extended from the ultraviolet (UV) region, through the entire visible (Vis) region, onto a significant portion of the near-infrared (NIR) portion of the solar spectrum with high absorption coefficients due to the infinite conjugation of Cu(I) with diimine ligands. Twenty-eight crystal structures were obtained by conventional crystal growth methods from organic solvents, whereas their bulk product syntheses also included "green chemistry" approaches that precluded the use of hazardous organic solvents. The resulting products are characterized by powder x-ray diffraction (PXRD), Fourier transform infrared (FTIR), nuclear magnetic resonance (NMR), UV/Vis/NIR absorption/diffuse reflectance/photoluminescence spectroscopies, and thermogravimetric analysis (TGA). Regarding the scientific phenomena investigated, the highlighting work in this dissertation is the discovery of novel bonding/photophysical/optoelectronic properties of the following materials: a black absorber with absorption from 200- 900 nm, a very stable compound with a bright green luminescence obtained by a solventless reaction, and a novel coordination polymer showing uncommon interaction of Ag(I) with three different types of diimine ligands simultaneously.

Thesis (MSc)--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: In this thesis the synthesis of a wide range of model and siloxane functionalized N-(n-propyl)-1-(2-pyridyl and quinolyl)-imine ligands (L1-L6) are described. Functionalized ligands (L4-L6) were obtained by the reaction of the pyridyl and quinolyl aldehydes with 3-aminopropyltriethoxysilane. Model ligands were characterized by FT-IR and 1H NMR spectroscopy while 13C{1H} NMR spectroscopy was additionally used for functional ligand characterization. Functionalized complexes of both Pd(II) and Cu(I) were found to be more thermally stable than their model counterparts. Overall the model Pd(II) complexes showed a higher thermal stability than the model Cu(I) complexes. Ligands (L1-L6) were reacted with either Pd(II) or Cu(I) metal precursors to produce both the model and functionalized Pd(II) (C1-C6) and Cu(I) (C7-C12) metal complexes. These metal complexes were all characterized by FT-IR spectroscopy, 1H NMR and UV/Vis spectroscopy for the model Cu(I) complexes. Functionalized complexes were additionally characterized with 13C{1H} NMR spectroscopy. Siloxane functionalized complexes of Pd(II) and Cu(I) were immobilized on MCM-41 and SBA-15 silica materials to produce heterogenized immobilized catalysts. These immobilized catalysts were characterized by a wide range of solid state techniques including: BET nitrogen adsorption/desorption, scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), ICP-AES, FT-IR spectroscopy, powder XRD and solid state 13C{1H} NMR spectroscopy. ICP-AES and BET surface analysis showed that better complex immobilization occurred for SBA-15 supported materials despite SBA-15 having a significantly lower surface area than MCM-41. This higher immobilization was ascribed to the larger pore sizes of SBA-15 (50 Å) vs. that of MCM-41 (26 Å). Immobilized catalysts were tested for the oxidation of benzyl alcohol to benzaldehyde. Immobilization had a positive effect on the catalytic activity of the Pd(II) complexes with higher conversions being observed for immobilized Pd(II) catalysts when compared to their model analogues. Overall the MCM-41 immobilized Pd(II) catalysts showed a higher increase in activity than SBA-15 immobilized catalysts. For Ti-doped supports a generally higher activity was seen for the Ti-SBA-15 system. The Cu(I) systems however were not as effective in the oxidation reactions. / AFRIKAANSE OPSOMMING: In hierdie tesis word die sintese van `n wye reeks model sowel as gefunksioneerde N-(n-propiel)-1-(2-piridiel en kinoliel)-imien ligande (L1-L6) beskryf. Gefunksioneerde ligande (L4-L6) is gevorm deur die reaksie van piridiel en kinoliel aldehied met 3-amniopropieltriëtoksiesilaan. Model ligande is gekaraktariseer deur FT-IR en 1H KMR spektroskopie terwyl 13C{1H} KMR spektroskopie addisioneel gebruik is vir die karaktarisering van die gefunksioneerde ligande. Ligande (L1-L6) is gereageer met Pd(II) of Cu(I) metaal voorgangers om beide model sowel as gefunksioneerde Pd(II) (C1-C6) en Cu(I) (C7-C12) metaal komplekse op te lewer. Hierdie metaal komplekse is almal gekaraktariseer deur FT-IR, 1H KMR en UV/Vis spektroskopie vir die model Cu(I) komplekse. Gefunksionalseerde komplekse is addisioneel gekaraktariseer deur gebruik te maak van 13C{1H} KMR spektroskopie. Dit is gevind dat gefunksionaliseerde komplekse van beide Pd(II) sowel as Cu(I) termies meer stabiel was as hulle ooreenstemmende model komplekse. Oor die algemeen het die Pd(II) komplekse hoër termiese stabiliteit as die Cu(I) komplekse getoon. Siloksaan gefunksioneerde komplekse van Pd(II) en Cu(I) is geimmobiliseer op MCM-41 en SBA-15 silika materiale om heterogene geimmobiliseerde katalisatore op te lewer. Hierdie geimmobiliseerde katalisatore is gekaraktariseer deur van `n wye reeks vaste toestand tegnieke gebruik te maak. Hierdie suit in: SEM, TGA, ICP-AES, FT-IR, poeier XRD en vaste toestand 13C{1H} KMR spektroskopie. ICP-AES en BET oppervlak analieses het getoon dat beter kompleks immobilisering vir die SBA-15 silika material plaas gevind het, ondanks die feit dat SBA-15 `n laer oppervlak area beskik. Hierdie hoër graad van immobilisering is toegeskryf aan die groter poriegrootte van SBA-15 (50 Å) teenoor die van MCM-41 (26 Å). Geimmobiliseerde katalisatore is getoets in die oksidasie van bensielalkohol na bensaldehied. Dit is gevind dat die immobilisering van die Pd(II) komplekse op die silika materiaal `n positiewe uitwerking op die aktiwiteit van die katalitiese van die komplekse gehad het. Die hoogste toename in aktiwiteit is gesien vir geimmobiliseerde Pd(II) katalisatore wanneer hulle met hul ooreenstemmende model komplekse vergelyk is. Oor die algemeen is gevind dat MCM-41 geimmobiliseerde Pd(II) katalisatore n hoër toename in aktiwiteit getoon het as die van SBA-15. Vir die Ti-gedokterde silika materiale het die Ti-SBA-15 sisteem oor die algemeen `n hoër aktiviteit getoon as die Ti-MCM-41 sisteem. Die Cu(I) sisteme was egter nie so effektief in oksidasie reaksies nie.

Abstract Al-Omari, Mohammad Synthesis of Alkynes from Bi-3H-diazirin-3-yls: Trapping of Strained Cycloalkynes Chemnitz Technical University, Fakulty of Science Dissertation 2003, 76 pages. In this study, we have succeeded in synthesis of alkynes by a new method using bidiazirines as precursors. Different bidiazirinyl systems, such as acyclic, cyclic, and bicyclic systems, were investigated to show if they could serve as appropriate precursors for cycloalkynes. It has been shown that alkynes of no strain (e.g. 2-butyne) as well as extremely strained cycloalkynes (e.g. norbornyne) could be generated utilizing this method. This new method represents a simple, clean, and very efficient route to alkynes. That the strained cycloalkynes had actually been generated was shown by different trapping experiments. In these experiments, the thermal or photoextrusion of nitrogen atoms of the bidiaziridine moieties will certainly leads to the formation of a C,C triple bond, most probably through carbene intermediate. In terms of their reactions with the trapping dienes reagents, the generated cycloalkynes should be considered as normal, yet strained alkynes. In turn, bidiazirines were easily synthesized by oxidative dehydrogenation of their corresponding bidiaziridines. Bidiaziridines, which were the key step in the whole process, were successfully synthesized from bisdiimine precursors. It has been shown, that bisdiimines were the only suitable starting materials for the synthesis of bidiaziridines. Neither the diketones, nor the iminoketone derivatives proved to serve as appropriate starting materials. keywords: 1,2-diketon, 1,2-diimines, bidiaziridin, bidiazirin, strained cycloalkynes, Norbornyne, trapping agents, cycloaddition. / Bibliographische Beschreibung und Referat Al-Omari, Mohammad Synthesis of Alkynes from Bi-3H-diazirin-3-yls: Trapping of Strained Cycloalkynes Technische Universität Chemnitz, Fakultät für Naturwissenschaften Dissertation 2003, 76 Seiten. In der vorliegenden Arbeit wird eine neue Methode zur Synthese von Alkinen beschrieben. Ausgehend von acyclischen, mono- und bicyclischen 1,2-difunktionalisierten Vorläufern wurden Bidiazirine synthetisiert und deren Eignung als Precursoren für Alkine untersucht. Dabei musste festgestellt werden, dass sich weder von 1,2-Diketonen noch von Iminoketonen die als Zwischenprodukte benötigten Bidiaziridine direkt darstellen ließen. Der einzige erfolgreiche Syntheseweg führte über die 1,2-Diimine zu Diastereomeren-Gemischen der gewünschten Bidiaziridine. Die Oxidation der Bidiaziridine lieferte die Bidiazirine, welche als Vorstufen für die Synthese von Alkinen dienten. So konnten auf diesem Wege sowohl spannungsfreie lineare Alkine wie 2-Butin als auch extrem gespannte Cycloalkine wie Cyclohexin oder Norbornin synthetisiert werden. Der spektroskopische Nachweis der Alkine erfolgte dabei direkt bzw. über verschiedene Abfangprodukte. Stichworte: 1,2-Diketon, 1,2-Diimine, Bidiaziridin, Bidiazirin, gespannte Cycloalkine, Norbornin, Abfangreagentien, Cycloaddition.