Ion exchange chromatography (IC) is an analytical technique used to separate charged molecules including ions, proteins, small nucleotides, and amino acids. It can function in anion or cation mode. In this dissertation, anion exchange chromatography was used, and column materials were made in our lab with resorcinarene-based compounds called cavitands. Cavitands create cavities to bind to molecules because of their three-dimensional structure. Two new gradient IC methods were established to identify and quantify perrhenate and perfluoroalkyl substances (PFAS) by customized resorcinarene-based column, zinc cyclen resoecinarene (ZCR) and arginine methyl ester (RUE) columns. The ZCR column accomplished outstanding separation of perrhenate from other anions such as chloride and sulfate by using a gradient elution of 2-60 mM NaOH. There was a logarithmic relationship between the perrhenate concentration and its retention time. In addition to separating anions, the ZCR column was able to preconcentrate perrhenate with over 90% recovery in different conditions. RUE was successfully synthesized and attached to polystyrene resin and used in IC to separate the PFAS, perfluorobutanoic acid (PFBA), perfluoropentanoic acid (PFPeA), perfluorobutanesulfonic acid (PFBS), perfluorohexanoic acid (PFHxA), perfluorohexanesulphonic acid (PFHxS), and perfluorooctanoic acid (PFOA). The sample preparation for the PFAS was simple and only needed filtration. A gradient method starting with 70 mM NaOH and going to pure water was necessary to separate the PFAS. There was no detectable PFAS in Provo tap water and Utah Lake water by our method. Although the LOD and LOQ of PFAS were not as low as the existing methods, the IC method does not require complicated sample preparation steps to separate and quantify PFAS. Binding studies of RUE and RUA were done with organic acids, including citric, malic, and succinic acid, and PFAS including PFBA, and PFHxA. The strongest binding was for L-malic acid followed by succinic acid, D-malic acid, pentanoic acid, citric acid, and dimethyl L-malate. RUE displayed some chiral recognition between L-malic acid and D-malic acid. Unfortunately, it did not show significant differences in binding between the different PFAS even though RUE had been able to separate them by IC.

No description available.

Ce travail de thèse porte sur la chimie organométallique des complexes pince indényle/indénediide de palladium et de platine et leurs applications en catalyse coopérative métal-ligand. Le premier chapitre de ce manuscrit fait un point bibliographique non-exhaustif du domaine de la coopérativité métal-ligand, des travaux de Noyori sur l'hydrogénation asymétrique, jusqu'aux récents travaux de Milstein avec les ligands désaromatisés. Les ligands pince sont également présentés. Du premier exemple PCP décrit par Shaw jusqu'au CNC développé par Bezuidenhout. La versatilité de ces ligands est illustrée à travers quelques modifications permettant des réactivités originales ou l'isolation d'espèces hautement instables. Le second chapitre présente une nouvelle réaction de formation de cycle avec le complexe pince indénediide de palladium. Cette réaction implique pour la première fois deux molécules de substrat, le CO2 comme source C1 et les propargylamines/homopropargylamines. L'étude mécanistique du système a permis d'établir l'implication de la coopérativité métal-ligand. Ensuite, le troisième chapitre est un chapitre de chimie exploratoire. De nouvelles réactivités ont été étudiées avec les complexes pince de platine. L'activation de liaisons peu polaires telles que H-H et H-Si ont permis la réduction de liaisons insaturées. Les propositions mécanistiques, qu'il reste à confirmer, semblent indiquer que les métathèses ?, ainsi que les insertions migratoires, sont possibles avec ces complexes. Finalement, le dernier chapitre est consacré au développement d'un nouveau ligand pince ayant la particularité d'être hémilabile et ouvrant ainsi la voie à de nouvelles réactivités. Sa coordination au palladium, ainsi que la déprotonation de ce dernier, a permis le développement d'un complexe coopératif qui a été testé en cycloisomérisation. L'ensemble de ces travaux reflètent l'importance des ligands pince indényle/indénediide et de la coopérativité métal-ligand en catalyse. / This Ph.D. work deals with organometallic chemistry of indenyl/indenediide palladium and platinum pincer complexes and their applications in metal-ligand cooperative catalysis. The first chapter of this manuscript compiled a non-exhaustive bibliographic survey of the field of metal-ligand cooperation, from Noyori's system applied to the asymmetric hydrogenation, to the recent examples described by Milstein involving non-aromatic pincer ligands. Pincer ligands are also presented. Starting from the first example, in which Shaw shed light a PCP pincer, to the contemporary CNC pincer reported by Bezuidenhout. The versatility of those ligands is illustrated through few modulations allowing originals reactivities or stabilisation of highly unstable species. The second chapter is focused on the development of a new catalytic reaction with the indenediide palladium pincer complex. This reaction entail, for the first time, two substrates, the CO2 as a C1 source and propargylamines/homopropargylamines. The mechanistic studies turn out the importance of the metal-ligand cooperativity. Then, the third chapter concerns exploratory chemistry. New reactivities have been studied with the platinum complexes. The activation of low polar bond such as H-H and H-Si allowed the reduction of unsatured C-C bond. The mechanistic propositions, that remain to be confirmed, seem to indicate the feasibility of ? bond metathesis and migratory insertions. Finally, the last chapter is dedicated to the development of a new ligand. The latter showed the distinctive characteristic to be hemilabile, leading the way of new reactivities. His coordination to palladium, followed by his deprotonation to give rise to the non-innocent nature of the complex is presented, as well as the application of the resulting complex in the context of a cycloisomerisation. Those results are reflecting the importance of the indenyl and indenediide pincer ligands besides the metal-ligand cooperativity in catalysis.

No description available.

This thesis focuses on the design, synthesis and development of dynamic multivalent nanostructures such as supramolecular dendrimers, liposomes and gold-functionalized nanostructures. These structures can be used for drug delivery and molecular sensing applications. This thesis is divided into three parts: In part one, a general introduction to self-assembly, dynamic systems, metalligand exchange, nanostructured dendritic scaffolds, liposomes and gold nanostructures is given. In part two, a microwave approach is presented as an efficient method for the regioselective deuteration of bipyridine scaffolds. Dynamic systems based on transition metal-bipyridine coordination complexes were investigated. The compositional self-adaptation and kinetics of these dynamic systems were successfully assessed by ESI-MS. Based on this amphiphilic dendrimers/metallodendrimers were also designed and synthesized via  a convergent strategy. Their ability to self-assemble into supramolecular assemblies and their controlled disassembly was effectively demonstrated. In part three, two types of drug delivery systems based on dynamic multivalent nanostructures of glycodendrimers/metalloglycodendrimers and drugpresenting liposomes were developed. The dynamic self-assembly of these architectures into supramolecular nanostructures with site-specific functionality through interacting carbohydrate or cholesterol moieties was assessed. The host-guest interaction/encapsulation and controlled release with external stimuli were studied using a fluorescent probe, as well as selected drug molecules. The antibacterial property of the drug delivery systems was also evaluated, demonstrating an enhanced bactericidal activity. A new, rapid and simple approach for the functionalization of plasmonic gold nanostructured surfaces was also developed. The optical performance and light-specific sensitivity of the fluorescent probe on the resulting nanostructures were also presented. / <p>QC 20151119</p>

The work highlighted in this dissertation comprises of syntheses and characterizations of coordination driven supramolecular compounds. The synthesized complexes are characterized by IR spectroscopy, multinuclear NMR spectroscopy and single crystal structure determination. Chapter 2: In this chapter we attempted to make a three dimensional self-assembled cage by the reaction between N, N’, N’’- tris(3-pyridyl)trimesic amide a tritopic donor and Pt(II) based 90° ditopic acceptor cis-(dppe)Pt(II)(OTf)2 [dppe = 1,2-bis(diphenylphosphino)ethane]. It resulted in a trigonal bipyramidal structure. The cage was characterized by single crystal XRD and FT-IR spectra. Chapter 3: In this chapter we have reported the synthesis and characterization of two hereby unknown metal containing carboxylic acid ligands containing the Pt-ethynyl moiety. Also we have shown the preparation and structure analysis of a copper containing metal-organic framework incorporating one of the Pt-ethynyl containing carboxylic acid ligand. This has resulted in the formation of a very interesting hetero-metallic MOF which is quite uncommon in literature.

Self–assembly has long been attracting chemists’ attention because it can yield fascinating supramolecular architectures in a single step. More precisely, metal–ligand coordination–driven self–assembly has stood out as an efficient methodology in this paradigm due to simple design principle and high predictability of the final molecular architectures. Moreover, one can envisage hierarchical nanoscopic molecular architectures with a vast range of size, shape and functionality via this methodology. Two–component self–assembly (involving one type of donor and one type of acceptor) is relatively easy to monitor and a widely used protocol. Whereas, multicomponent self–assembly (involving more than one types of donors/or acceptors) is too complex due to the possibility of formation of several products. The prime advantage of multicomponent self–assembly lies in one–pot construction of topologically complicated multifunctional architectures. Template– induced multicomponent self–assembly of discrete architectures is recently investigated to some extent. But, template–free multicomponent self–assembly of discrete architectures is rare in the literature. Physico–chemical property of a self–assembled product is coded in the functional groups present in its precursor building units. Functional supramolecular architectures have important applications in many potential fields such as chemosensing, drug delivery, supramolecular catalysis, etc. Porphyrin, pyrazole, imidazole, etc. functionalized organic molecules are hydrophilic as well as hydrophobic in nature. Introduction of such functionality in building units can lead to amphiphilic supramolecular complexes. Therefore, such complexes can be employed as hosts for versatile guests, or as molecular reactors for various chemical reactions. In general, counter ions block the cavity of ionic molecular architectures. Thus, when ionic molecular architectures are employed as hosts, they cannot fully provide their cavity towards guest molecules. In contrast, neutral molecular complexes are expected to be better hosts. It is well known that alkenyl/alkynyl heavy metal complexes exhibit efficient chemoluminescence due to facile metal to ligand charge transfer (MLCT). Hence, such complexes can be employed as efficient chemosensors towards the detection of electron deficient molecules such as nitroaromatics which are the chemical signatures of many powerful explosives. In these regards, a considerable effort is being paid recently to design and construct various functional supramolecular architectures. Symmetry and rigidity of building units increase predictability of the final product in self– assembly. In this regard, symmetric; rigid Pd(II)/Pt(II)–based acceptors and polypyridyl donors are explored extensively in metal–ligand coordination–driven self–assembly. In contrast to rigidity, flexibility endows building units to adopt thermodynamically most stable conformer/architecture. Hence, same set of building units can render different conformers/architectures in presence of different templates for the sake of suitable host–guest interactions. Contrary to high symmetry, asymmetry in building units leads to molecular architectures with polar environments. But, due to the possibility of formation of several isomeric products from the self–assembly involving such building units, it is difficult to monitor the reaction and purify the products. Hence, designing appropriate synthetic routes which can lead to formation of single isomeric products possessing flexible/asymmetric building units is a challenge to synthetic chemists. Investigations incorporated in the present thesis are focused to design and construct various 2D/3D discrete supramolecular architectures employing self–assembly of mainly Pd(II)/Pt(II) acceptors with N/O donors. Elemental analyses, IR/NMR/UV–Vis/fluorescence/mass spectroscopy and single crystal X–ray diffraction analysis are among prime techniques employed for characterization of the reported architectures. For a few cases, powder X–ray diffraction (PXRD) analysis and density functional theory (DFT) calculations are also carried out. CHAPTER 1 of the thesis provides a brief general introduction to self–assembly and supramolecular chemistry. It emphasizes on the metal–ligand coordination–driven self–assembly approach towards the construction of a library of 2D/3D supramolecular architectures. CHAPTER 2 describes formation of a series of template–induced and template–free discrete 3D Pd(II) molecular prisms via multicomponent self–assembly. Because of the possibility of formation of several products, multicomponent self–assembly is difficult to monitor. For example, several molecular architectures are expected from a three–component self–assembly involving a 90° acceptor [ca. cis–blocked Pd(II)], a 120° tritopic donor [ca. benzene–1,3,5– tricaboxylate (tma)] and a 180° donor [ca. 4,4'–bipyridine (4,4'–bpy) or pyrazine (pz)]. Interestingly, treatment of cis–(tmen)Pd(NO3)2 [tmen = N,N,N′,N′–tetramethylethylenediamine] with 4,4'–bpy and K3tma in 6 : 3 : 2 molar ratio at room temperature resulted in mainly a nanoscopic molecular trigonal prism [{(tmen)Pd}6(bpy)3(tma)2](NO3)6 (1) with three 4,4'–bpy pillars, two tma caps and six cis–(tmen)Pd connectors (Scheme 1). Scheme 1: Schematic representation of the formation of multicomponent self–assembled molecular trigonal prisms 1, 2 and 3. Surprisingly, the same reaction in presence of benzene–1,3,5–tricaboxylic acid (H3tma) as guest yielded exclusively the guest–encapsulated analogous molecular prism [{(tmen)Pd}6(bpy)3(tma)2(H3tma)2](NO3)6 (2; Scheme 1). It is also presented how variation of steric crowding at connectors (acceptors) influenced final outcomes. Self–assembly of cis– (en)Pd(NO3)2 [en = ethylenediamine] with 4,4'–bpy and K3tma in 6 : 3 : 2 molar ratio at room temperature resulted in a triply interlocked nanoscopic 3D coordination cage [{(en)Pd}6(bpy)3(tma)2]2(NO3)12 (3; Scheme 1). It is also shown that above trend is followed even upon changing the pillar length from 4,4'–bpy to pz. Aromatic –stacking interactions amog tma caps as well as among 4,4'–bpy pillars provided considerable stability to interlocked archirecture 3. Steric crowding due to the methyl groups in cis–(tmen)Pd connectors hindered intercalation and hence led to non–interlocked architecture 1. As expected, similar self–assembly using moderately crowded acceptor cis–(pn)Pd(NO3)2 [pn = 1,2–diaminopropane] with same donors 4,4'–bpy and K3tma resulted in a mixture of analogous triply interlocked and non– interlocked architectures in solution though it was found to be only triply interlocked architecture in solid state. Interestingly, irrespective of the steric crowding of the blocking amines, self– assembly in presence of H3tma as guest preferred exclusive formation of guest–encapsulated prisms of type 2 (Scheme 1). This is due to considerable stabilazation via aromatic –stacking interactions amog tma caps and H3tma guests. Formation of guest–free discrete molecular prisms (such as 1) and triply interlocked coordination cages (such as 3) were confirmed by spectroscopic and single crystal X–ray diffraction analyses. Whereas, formation of guest– encapsulated discrete molecular prisms (such as 2) was established by DOSY, ROESY 2D NMR spectroscpic study in conjunction with energy optimized geometry analysis. CHAPTER 3 reports design and syntheses of a series of porphyrin functionalized nanoscopic 3D molecular open prisms. Self–assembly of a C4 –symmetric tetratopic donor with a 90° ditopic acceptor can, in principle, lead to several architectures such as trigonal; tetragonal; pentagonal; hexagonal; etc. open prisms, closed cube or 1D oligomers. Both of 1,5,10,15–tetrakis(4– 12 pyridyl)porphyrin (L) and 1,5,10,15–tetrakis(3–pyridyl)porphyrin (L) possess pseudo C4 – 1 symmetry. Surprisingly, treatment of Lwith the 90° ditopic acceptor cis–(dppf)Pt(OTf)2 [dppf = diphenylphosphinoferrocene, OTf = trifluoromethanesulphonate] yielded exclusively an 1 unprecedented [6 + 12] self–assembled hexagonal open prism [(dppf)12Pt12L6](OTf)24 (4; Scheme 2). Scheme 2: Schematic representation of formation of [6 + 12] self–assembled molecular hexagonal open prism 4 and its Zn(II) embedded complex 4a. 2 In contrast, [3 + 6] self–assembled trigonal open prisms are adopted upon self–assembly of Lwith Pd(II)–based 90° ditopic acceptors. These complexes show facile incorporation of Zn(II) ions into porphyrin N4 –pockets. Moreover, they incorporate high microporosity in solid state and they are amphiphilic in nature due to porphyrin functionality. One of the trigonal open prisms revealed its considerably high adsorbate–adsorbent affinity towards non–polar gas such as N2 and protic solvent vapors such as water, methanol and ethanol. Formation of hexagonal and trigonal open prisms is fully authenticated by spectroscopic and single crystal X–ray diffraction analyses. CHAPTER 4 describes design and synthesis of a pyrazole functionalized flexible donor (L) and its self–assembly towards the construction of three nanoscopic 3D supramolecular discrete cages 5–7 (Scheme 3). Scheme 3: Schematic representation of formation of [4 + 6] self–assembled molecular double–square 5 and [2 + 3] self–assembled molecular trigonal bipyramids 6–7. 3 Due to flexibility, Lcan adopt different conformations and hence several isomeric architectures 3 are expected upon self–assembly. For example, self–assembly of Lwith a rigid ditopic 90° acceptor can lead to trigonal bipyramid (TBP), double–square, adamantanoid or truncated 3 tetrahedron. Treatment of Lwith cis–(tmen)Pd(NO3)2 yielded a [4 + 6] self–assembled double–3 square [(tmen)6Pd6L4](NO3)12 (5; Scheme 3). Much to our surprise, replacement of cis– (tmen)Pd(NO3)2 with CuCl2 or AgOTf yielded [2 + 3] self–assembled molecular TBP 33 [Cu3Cl6L2] (6) or [Ag3L2](OTf)3 (7), respectively (Scheme 3). CHAPTER 5 presents study of self–assembly involving flexible asymmetric donors and rigid 4 symmetric 90° acceptors. Three ambidentate donors 5–pyrimidinecarboxylate (L), nicotinate–56 N–oxide (L) and isonicotinate–N–oxide (L) were employed in self–assembly with symmetric rigid 90° acceptors cis–(dppf)M(OTf)2 [M = Pd(II)/Pt(II)]. Due to flexibility and different 464 connectivity of these donors L–L, several linkage isomers are expected. Treatment of Lwith cis–(dppf)M(OTf)2 in 1 : 1 molar ratio resulted in exclusive formation of single linkage isomeric 4 [3 + 3] self–assembled symmetric molecular triangles [(dppf)3M3L3](OTf)3 (8: M = Pd and 9: M = Pt), where the donors connected to metal centers in head–to–tailfashion (Scheme 4). Similar 56 reactions of Land Lwith cis–(dppf)M(OTf)2 resulted in self–sorting of [2 + 2] self–assembled molecular rhomboids 10–13 (Scheme 4). Exclusive self–selection of single linkage isomeric architectures 8, 9, 10 and 12 was fully established by spectroscopic as well as single crystal X– ray diffraction analyses. Though we could not obtain suitable X–ray diffraction quality single crystals of 11 and 13, exclusive formation of single isomeric [2 + 2] self–assembled rhomboids 131 was established by multinuclear NMR (H and P) in conjunction with ESI–MS spectroscopic studies. Scheme 4: Schematic representation of formation of complexes 8–13. Part A of the CHAPTER 6 describes how two neutral organometallic mononuclear chelates are formed upon treatment of disodium fumarate (,–unsaturated dicarboxylate) with cis– (dppf)Pd/Pt(OTf)2 at ambient conditions. Reaction of 90acceptors cis–(dppf)Pd/Pt(OTf)2 with fumarate is expected to result in [4 + 4] self–sorted molecular squares/or [2 + 2] self–sorted molecular rhomboids (Scheme 5). To our surprise, the above reactions led to an unusual reduction of C–C double bond followed by concomitant formation of mononuclear chelates [M(dppf)(C4H4O4)] (M = Pd for 14 and Pt for 15) via coordination with one of the carboxylate oxygen atoms and –carbon to metal centers (Scheme 5). Scheme 5: Schematic representation of formation of the complexes 14–15. Part B of the CHAPTER 6 describes design and synthesis of a novel shape selective “clip” 1 shaped bimetallic Pd(II) acceptor Mand its self–assembly with disodium fumarate to construct a neutral tetrametallic Pd(II) supramolecular rectangle 16 (Scheme 6, left). Similarly, a shape selective 180° bimetallic Pd(II) acceptor was also synthesized and employed in self–assembly with several “clip” shaped organic donors to achieve several cationic tetrametallic Pd(II) supramolecular rectangles. Scheme 6: Schematic representation of the formation of neutral Pd4 (left) and Pd2 (right) molecular rectangles. Moreover, synthesis of a neutral bimetallic Pd(II) molecular rectangle 17 via one–pot reaction of trans–(PEt3)2PdCl2 with 1,8–diethynylanthracene (Scheme 6, right) is also presented herein. These –electron rich rectangles exhibit prominent chemoluminescence. Chemosensitivity of these complexes towards the detection of electron deficient nitroaromatics via fluorescence study is also discussed in details in this section. (Pl refer the abstract file for figures).

No description available.