Tesi: "Crown ethers"

1

Huang, Zilin. "Synthesis and Complexation Studies of Novel Functionalized Crown Ethers and Azacrown Ethers". Thesis, University of North Texas, 2006. https://digital.library.unt.edu/ark:/67531/metadc5593/.

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Novel cage-functionalized azacrown ethers, i.e. 51, 52, 53, 55, 57, 61 and 62, which have various crown cavity and different number of nitrogen atoms incorporated, have been prepared. X-ray structures of 53, 55 and 57 have been obtained for the study of the crown topological structure. The complexation properties of crown 51, 52, 57, 61 and 62 have been evaluated via alkali metal picrate extraction, silver picrate extraction and ESI-MS study. The novel cage-fuctionalized azacrown ethers generally exhibit high avidity and selectivity towards Ag+ versus alkali metal ions and some transition metals i.e. Cu2+, Mn2+, Zn2+, Ni2+ and Pb2+. Crown 61 displays significant avidity and selectivity toward K+ in alkali metal picrate extraction experiments vis-à-vis the remaining alkali metal picrates. Three types of ditopic ion-exchange receptors for sodium hydroxide extraction study have been designed. All of the crown ether molecules have proper cavity for selective sodium complexation and have weakly acidic ionizable alcohols for sodium-proton exchange under strongly basic conditions. Crown 80 and 81 were synthesized; key intermediates for the synthesis of crown 82, 83 and 84 have been prepared. The preparation of 99 afforded an unexpected crown 103. The preparation of 109 had been attempted, but could not be successfully isolated. Four novel cage-functionalized calix[4]arene crown-5, i.e. 113-116, have been synthesized. The structures of 113 and 116 have been established by X-ray crystal structural analysis and NMR spectral analysis. The complexation properties of the four ionic receptors have been studied via alkali metal picrate extraction experiments. Crown 115 and 116 display more than modest avidity toward alkali metal ions and are most selective toward K+ vis-à-vis 113 and 114.

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2

Owens, K. A. "Polycyclic crown ethers incorporating cyclophane units". Thesis, University of Liverpool, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370864.

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3

Wilson, Mark James. "Activity relationships for aromatic crown ethers". Thesis, University of Strathclyde, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.249872.

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4

Huang, Zilin. "Synthesis and Properties of Novel Cage-Annulated Crown Ethers". Thesis, University of North Texas, 2003. https://digital.library.unt.edu/ark:/67531/metadc5523/.

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Three cage-functionalized polyoxacrown ethers (9, 10 and 12) and four novel cage-functionalized polyoxamonoazacrown ethers (18, 20, 25 and 29) that contain 3,5-disubstituted-4-oxahexacyclo[5.4.0.02,6.03,10.05,9.08,11]dodecane ("oxahexacyclic") moiety have been synthesized and their respective alkali metal picrate extraction profiles along with that of three analogues 13, 14 and 21 have been obtained. The observed avidities and selectivities of the host molecules toward complexation and transport of alkali metal picrates can be related to the size and shape of their respective macrocyclic cavity and the number of donor atoms. The effect of N-alkyl substitution on the complexation properties of azacrown ethers has been studied. The avidity of N-Et azacrown ethers toward complexation with alkali metal cations is generally higher than that of the corresponding non-N-alkylated hosts. However, the presence of an N-Et group appears to have a negligible effect upon their relative selectivities in their regards. The effect of pH on extraction process was studied; it was thereby determined that the alkali metal picrate extraction experiments are best performed at high pH (ca. 11-12).

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5

Denike, John Kane Carleton University Dissertation Chemistry. "The synthesis and complexation of bis-crown ethers and polymers bearing pendant crown ethers and the study of molecular motion of crown ethers in solids using solid state 2H NMR". Ottawa, 1992.

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6

Ji, Mingzhe. "Explorations with optically active, cage-annulated crown ethers". Thesis, University of North Texas, 2003. https://digital.library.unt.edu/ark:/67531/metadc4207/.

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A variety of optically active macrocyclic crown ethers that serve as "host" systems that are capable of differentiating between enantiomeric "guest" molecules during host-guest complexation have been prepared via incorporation of chiral elements into the crown ring skeleton. The ability of these crown ethers to recognize the enantiomers of guest salts, i.e., (+) a-methyl benzylamine and to transport them enantioselectively in W-tube transport experiments were studied. The ability of these crown ethers to perform as chiral catalysts in an enantioselective Michael addition was studied. The extent of asymmetric induction, expressed in terms of the enantiomeric excess (%ee), was monitored by measuring the optical rotation of the product and comparing to the literature value.

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7

Merithew, Andrew William. "Differential Self-Assembly of Novel Redox Crown Ethers". Thesis, University of California, Santa Barbara, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3645672.

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Retinal prosthesis relies on the stimulation of living nerve tissue behind the rods and cones of the eye. The current state of the art relies on electrodes controlled by cameras which directly stimulate the nerve tissue to elicit a response to an image. These types of retinal implants have allowed for short-term crude vision in patients but have had limited long term success due to external battery packs and electroplating of the implanted electrodes.

Ionic stimulation is one of the principle mechanisms that sensory neurons utilize in the generation of an action potential. In a complex transduction pathway, ionic gradients are constantly altered inside the neuron by voltage sensors or mechanically controlled gates embedded in the neuronal cell membrane; responsible for the open and close state of these ion channels.

It has been demonstrated that local concentration increases of K⁺ by direct injection proximal to the nerve can elicit nerve firing at a concentration of 15-20 mM (3-4X normal concentration) increase in K⁺ concentration. As part of a larger concept of integrating biotechnology with nanofabrication, the materials for the development of potassium selective sequestration/storage and delivery were developed in the form of a redox-gated K⁺ selective crown ether.

The structure of the anthraquinone-based crown was deduced by computational simulation and stoichiometry of the complex confirmed by mass spec. along with 2D diffusion NMR techniques. In this instance, the stoichiometry could be controlled by the addition of different salts to give a 1:1 complex with large, aromatic anions and a 2:1 complex with smaller anions such as triflate. The synthesis of the molecule was optimized by computational modeling and simulations of transport through an artificial membrane. The selectivity of the architecture developed was specific for K⁺ over Na+, the other major ionic species present in the blood. The mechanism influencing the self-assembly of this class of compounds has much to do with the breakage of intramolecular π-stacking interactions and the formation of stronger intermolecular π-stacking interactions.

Finally, the transport of K⁺ through nanoporous membranes and single nanopores with novel PEG-type polymeric dispersions is demonstrated. This thesis concludes with future work toward developing more advanced transporters and proposes novel uses for anthraquinone-appended polymers as proton exchange membranes and DNA-base pair interchelators.

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8

D'Souza, Lawrence Joseph. "Bile Acid Based Molecular Tweezers And Crown Ethers". Thesis, Indian Institute of Science, 1995. https://etd.iisc.ac.in/handle/2005/114.

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Chapter 1. Introduction to Molecular Tweezers Whitlock and Zimmerman developed a class of molecular hosts, popularly known as molecular tweezers, which sandwich aromatic guests by ii=ii interaction. Chapter 1 summarizes molecular tweezers of various kinds which have recently been synthesized. Chapter 2. Design and synthesis of "Bile Acid-Based Molecular Tweezers" Bile acids have a rigid backbone, and the array of hydroxyl groups separated by 5-7 A provides opportunities for the attachment of binding surfaces such as two extended chromophoric units.

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9

D'Souza, Lawrence Joseph. "Bile Acid Based Molecular Tweezers And Crown Ethers". Thesis, Indian Institute of Science, 1995. http://hdl.handle.net/2005/114.

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Chapter 1. Introduction to Molecular Tweezers Whitlock and Zimmerman developed a class of molecular hosts, popularly known as molecular tweezers, which sandwich aromatic guests by ii=ii interaction. Chapter 1 summarizes molecular tweezers of various kinds which have recently been synthesized. Chapter 2. Design and synthesis of "Bile Acid-Based Molecular Tweezers" Bile acids have a rigid backbone, and the array of hydroxyl groups separated by 5-7 A provides opportunities for the attachment of binding surfaces such as two extended chromophoric units.

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10

Landry, Denis Joseph Carleton University Dissertation Chemistry. "Approaches to the synthesis and sterochemical analysis of aza crown ethers". Ottawa, 1989.

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11

McClean, G. O. "Fluorescent sensors based on benzo-15-crown-5 ethers". Thesis, Queen's University Belfast, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.403172.

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12

Moody, T. S. "Switches based on crown ethers, cyclophanes and amino acids". Thesis, Queen's University Belfast, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390876.

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13

Mousley, David P. "The application of bis(benzo)-crown ethers as multireceptors". Thesis, University of Newcastle Upon Tyne, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295075.

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14

Rademacher, Christine Marie Koebel. "Synthetic studies toward pederic acid and photochromic crown ethers". The Ohio State University, 1997. http://rave.ohiolink.edu/etdc/view?acc_num=osu1311869400.

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15

Tseki, Potlaki Foster. "Metal complexes of thiophene analogues of crown ethers and cryptands". Thesis, Nottingham Trent University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386053.

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16

Ghorbanian, Shohreh. "Studies of potentially useful thiol-reactive fluorescent probes and novel ion-responsive fluorescent quinoxalinone derivatives". Thesis, Brunel University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360815.

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17

Yonekawa, Sayuri. "The synthesis and study of an amine functionalized crown ether". Virtual Press, 2004. http://liblink.bsu.edu/uhtbin/catkey/1295147.

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This study has resulted in a route to the first known NHZ functionalized xylenebased crown ether, 5-amino-2-methoxy-1,3-xylyl-18-crown-5. The route involves preparing 5-azido-2-methoxy-1,3-xylyl-18-crown-5 from 5-bromo-2-methoxy-1,3-xylyl18-crown-5 by reacting it in turn with n-BuLi and tosyl azide. 5-Amino-2-methoxy-1,3xylyl-l8-crown-5 was obtained by reducing 5-azido-2-methoxy-1,3-xylyl-l8-crown-5 with aqueous sodium borohydride in the presence of a phase transfer agent. The 'H NMR spectrum of the amino derivative showed NMR signals at 6 3.4-3.7 (crown CHZ), S 4.0 (benzylic), S 4.47 (methoxy), and 6 6.58 (aromatic) ppm. The integrated areas were consistent with the formula, and they also suggested the NH2 protons were in the crown CH2 area. The IR (KBr pellet) spectrum showed bands at 3408 cm' and 3364 cm' corresponding to the N-H asymmetric and symmetric stretches, respectively. This study has also provided a new procedure for the preparation of 4-bromo-2,6-bis(bromomethyl) anisole, which was the intermediate for 5-bromo-2-methoxy-1,3-xylyl-18-crown-5. It involved reacting 4-bromophenol in turn with 30 % formaldehyde, dimethylsulfate, and HBr in acetic acid.
Department of Chemistry

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18

Meehan, Paul R. "Complexation of neutral and cationic scandium(III) species with macrocyclic ligands". Thesis, University of Warwick, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.339827.

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19

Hazlewood, Anna. "Synthesis and properties of novel cage-functionalized crown ethers and cryptands". Thesis, University of North Texas, 2001. https://digital.library.unt.edu/ark:/67531/metadc2896/.

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A novel cryptand was synthesized which contained a 3,5-disubstituted-4- oxahexacyclo[5.4.1.02,6.03,10.05,9.08,11] dodecane "cage" moiety. In alkali metal picrate extraction experiments the cryptand exhibited high avidity towards Rb+ and Cs+, when compared with the corresponding model compound. A computational study of a series of cage-functionalized cryptands and their alkali metal-complexes was performed. The X-ray crystal structure of a K+-complexed bis-cage-annulated 20-crown-6 was obtained. The associated picrate anion was found to be intimately involved in stabilization of the host-guest complex. The interaction energy between the host-guest complex and picrate anion has been calculated, and the energy thereby obtained has been corrected for basis set superposition error.

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20

Baniasadi, Hamid R. "The synthesis and study of new phosphines functionalized with crown ethers". Virtual Press, 2008. http://liblink.bsu.edu/uhtbin/catkey/1398707.

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The goal of this research was to synthesize and study new phosphine crown ethers. The first target molecule was 5-phenylphoshinobis(2-hydroxy,1,3-xylyl-18-crown-5). We tried to synthesize this target molecule in six steps. 5-Bromophenol was reacted with formaldehyde, dimethylsulfate, phosphorus tribromide and tetraethylene glycol in the presence of sodium hydride producing the main intermediate molecule, 5-bromo-2-methoxy-1,3-xylyl-l8-crown-5. This molecule was reacted with n-butyllithium and dimethyl phenylphosphinite at the low temperature . NMR evidence indicated that was not obtained.The second target molecule, the oxide of 5-phenylphosphinobis(2-hydroxy-1,3-xylylcrown-5) was synthesized in nine steps. The main intermediate, 5-bromo-2-methoxy-1,3-xylyl-18-crown-5 was reacted with n-butyllithium and dimethyl phenylphosphinite to form the phosphine. This phosphine was oxidized with hydrogen peroxide. The OCH3 bond of this crown ether was cleaved by using LiI in boiling anhydrous pyridine. NMR data indicated the product was formed.
Department of Chemistry

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21

Acord, Douglas A. "The synthesis and study of 5-oxime-2-methoxy-1,3-xylyl-18-crown-5". Muncie, Ind. : Ball State University, 2009. http://cardinalscholar.bsu.edu/634.

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22

Amoozgar, Zohreh. "Synthesis and study of dibenzodihydroxy-26-crown-8". Virtual Press, 2007. http://liblink.bsu.edu/uhtbin/catkey/1371681.

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The objective of this research was to synthesis dibenzo-dihydroxy-26-crown-8 (1) as an ionophore for variety of chemosensors. Complexation of the ionophore (1) to a cation would cause a change of conformation. The conformational changes could affect fluorescence, UV spectra and/or Carbon-13 NMR of the chemosensor, depending on the fluorophores attached to the hydroxyl groups of crown 1 and/ or the identity of the ion. Several synthetic routes for crown 1 formation are given in the proposed synthetic procedure. Bis-1,2[2-hydroxyethoxy]benzene (17), bis-1,2[2-(3-chloro-2-hydroxypropoxy)ethoxy]benzene (18), bis-1,2[2-(2,3-epoxypropoxy)ethoxy]benzene (19) and bis-1,2[2(3-chloro-2-oxopropoxy)ethoxy]benzene (22) were synthesized. The reaction of 17 and 19 was attempted in the presence of SnC14, basic and acidic conditions, and in several solvents. The reaction of 17 and 22, and the reaction of 17 and 1,3-dichloroacetone were attempted in various reaction conditions. Crown 1 may have formed in the reaction of 17 and 19 in methylene chloride/ toluene in the presence of SnCl4 as the Lewis acid.
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23

Kleissler, Charles Richard. "Comparison of poly(vinyl alcohol) backbone-grafted ethers and chain-growth crown ether polymers in selective cation adsorption". Diss., Georgia Institute of Technology, 1987. http://hdl.handle.net/1853/10115.

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24

Simpson, Michael Alan. "Synthesis and characterisation of potential ion conducting materials incorporating crown ethers". Thesis, Heriot-Watt University, 1997. http://hdl.handle.net/10399/690.

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25

Chen, Zhibing. "Synthesis and host-guest interaction of cage-annulated podands, crown ethers, cryptands, cavitands and non-cage-annulated cryptands". Thesis, University of North Texas, 2003. https://digital.library.unt.edu/ark:/67531/metadc4229/.

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Symmetrical cage-annulated podands were synthesized via highly efficient synthetic strategies. Mechanisms to account for the key reaction steps in the syntheses are proposed; the proposed mechanisms receive support from the intermediates that have been isolated and characterized. An unusual complexation-promoted elimination reaction was studied, and a mechanism is proposed to account for the course of this reaction. This unusual elimination may generalized to other rigid systems and thus may extend our understanding of the role played by the host molecules in "cation-capture, anion-activation" via complexation with guest molecules. Thus, host-guest interaction serves not only to activate the anion but also may activate the leaving groups that participate in the complexation. Complexation-promoted elimination provides a convenient method to desymmetrize the cage while avoiding protection/deprotection steps. In addition, it offers a convenient method to prepare a chiral cage spacer by introducing 10 chiral centers into the host system in a single synthetic step. Cage-annulated monocyclic hosts that contain a cage-butylenoxy spacer were synthesized. Comparison of their metal ion complexation behavior as revealed by the results of electrospray ionization mass spectrometry (ESI-MS), alkali metal picrate extraction, and pseudohydroxide extraction with those displayed by the corresponding hosts that contain cage-ethylenoxy or cage-propylenoxy spacers reveals the effect of the length of the cage spacer upon the host-guest behavior. A series of cage-annulated cryptands, cavitands and the corresponding non-cage-annulated model compounds have been synthesized. These host molecules display unusual behavior when examined by using ESI-MS techniques, i.e., they bind selectively to smaller alkali metal ions (i.e., Li+ and Na+), a result that deviates significantly from expectations based solely upon consideration of the size-fit principle. It seems likely that this behavior results from the effect of the host topology on host-guest behavior. A series of non-cage-annulated cryptands also have been synthesized. These compounds can serve as starting materials for cavitand construction.

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26

Keefer, Chad D. "The synthesis and study of a phosphine functionalized crown ether". Virtual Press, 2005. http://liblink.bsu.edu/uhtbin/catkey/1318448.

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This study has resulted in a phosphine funetionalized crown ether. synrdiQ-methoxy-5-diphenylphosphino-1.3-cplyl l-24-crown-6, obtained tkmt a live step synthesis. 4-13romophenol was treated in turn with formaldehyde. di methyl sulfate, and phosphorous trihromide. producing 4-bromo-2.6-his(bromomethyl )anisole. The key intermediate. spm-di(2-methoz}-5-bromo-I.3-z( I).l )-24-crown-6. was obtained from treating 4-hromo-3.6-bis(bromomethyl )anisole with diethylenc glycol and potassium thutoyide. The potassium ion apparently provided a template to assist the formation of the product. SLm-di(2-methosp-5-diphenylphosphino- I.3-x lyl )-24-crown-6 was obtained from treating sm-di(2-methos5-5-hromo-I.3-x'kI -24-crown-6 in sequence with n-BuLi and methyldiphern I phosphinite. The nP NMR of the phosphine crown ether showed a single signal at 6 -5.35 ppm. consistent with the formation of a single product.The'1I NMR of the phosphine crown ether in chloroform-d showed signals at6354-3.56 (crown CIF). 3.61 I OCI I;I. 4.44 (benzylic Cl I.6 and 7.25-7.29 (aromatic Ii) ppm.The integrated areas were consistent with the formula. The `C NNIR of the phosphine crown ether in chloroform-d displaced signals at 6 63.1, 68.5. 70.0. 70.1. 128.5 and 128.6 (d). 128.7. 131.8 and 131.9 (d), 132.0. 133.6 and 133.7 (d). 136.1 and 136.4 (d). 137.4 and 137.5 (dl, and 158.4 ppm. The "C signals were consistent with the formula and structure. The br)minated crown ether was characterized with 'I I and ''C NMR. as well as X-ray crystallography and elemental analysis.
Department of Chemistry

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27

Clarkson, Richard John. "An investigation of some oxygen heterocycles : their polymerisation and effect on polymer properties". Thesis, Lancaster University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360642.

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28

Shi, Danxin. "Preliminary research toward the total synthesis of a novel crown ether that is a potential fluorescent chemosensor for potassium ion recognition". Virtual Press, 1995. http://liblink.bsu.edu/uhtbin/catkey/941374.

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The purpose of this research was to synthesize a novel crown ether compound that has been designed to fluoresce with greatly enhanced intensities when in the presence of selected alkali metal cations. The novel crown ether compound (cryptand) 12,25-(1,5 - dimethyloxynaphtho)-1,4,7,10,14,17,20,23-octaoxacyclohexacosane (1) was synthesized through 6 steps. The general synthetic route for the preparation of cryptand 1 is given in the proposed synthetic procedure. Reaction of benzaldehyde (23) with glycerol (24) in the presence of concentrated sulfuric acid afforded cis and traps-1,3-O-benzylideneglycerol (25). Cis and trans-2-O-benzyl-1,3-O-benzylideneglycerol (27) was obtained when 1,3O-benzylideneglycerol (25) was treated with benzyl bromide (26) and sodium wire in benzene. Acid-hydrolysis of the 2-O-benzyl-1,3-O-benzylideneglycerol (27) in methanol gave 2-O-benzylglcerol (28). The key starting material is 12,25-bisbenzyloxy1,4,7,10,14,17,20,23-octaoxacyclohexacosane (31), which requires the formation of four carbon-oxygen bonds. 2-O-benzylglcerol (28) was reacted with triethyene glycol ditosylate and sodium hydride in dioxane. This treatment gave the product 12,25-bisbenzyloxy1,4,7,10,14,17,20,23-octaoxacyclohexacosane likely to be (31) along with the 1:1 and a 3:3 crown ether products. The compound likely to be (31) was treated with H2 and a Pd/Ccatalyst and the resulting compound was 12,25-dihydroxy-1,4,7,10,14,17,20,23Octaoxacyclohexacosane (2). Compound likely to be (2) was reacted with 1,5bis(bromomethy)naphthalene and potassium t-butoxide in tetrahydrofuran to give the final cryptand compound 1. The structures of the crown ethers, the products of this reaction, have not yet been unambiguously assigned.
Department of Chemistry

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29

Lai, Huiguo. "Design and Synthesis of Novel Cage-Functionalized Crown Ethers: A New Class of Ag Complexants". Thesis, University of North Texas, 2003. https://digital.library.unt.edu/ark:/67531/metadc4314/.

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Three different types of cage crown ethers have been prepared and their complexation properties with Ag(I) have been studied. Atomic absorption, fluorescence quenching, and UV absorption have been used to study the interaction between the hosts (cage crown ethers) and guests (Ag+). For the cage-annulated crown ethers that contain aromatic rings, cation-π and π-π interactions may contribute significantly to the overall complexation ability of the host system. Piperazine groups may cooperate, and the piperazine nitrogen atoms provide unshared electrons, which may form a complex with Ag+. In addition, relatively soft donor atoms (e.g., Br) are well-suited for complexation with Ag+, which is a softer Lewis acid than alkali metal cations.

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30

Kiviniemi, S. (Sari). "Complexation of N-heteroaromatic cations with crown ethers and tetraphenylborate". Doctoral thesis, University of Oulu, 2001. http://urn.fi/urn:isbn:9514259971.

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Abstract Study was made of host-guest complexation of neutral crown ethers with five- and six-membered N-heteroaromatic cations and purinium cation. Complexation of tetraphenylborate with selected N-heteroaromatic cations and tropylium cation also was studied. Crown ether complexes were characterized by mass spectrometric and 1H NMR spectrometric methods and by X-ray crystallography. Fast atom bombardment mass spectrometry (FABMS) was used as a prelimary tool to characterize the complexes and electrospray ionization mass spectrometry (ESIMS) was used to confirm the complexation stoichiometry. Crystal structures were determined by X-ray crystallography to study the complexation in solid state, and stability constants were measured in acetonitrile by 1H NMR titration at 30 °C to study the complexation in solution. Mass spectrometric studies indicated preferential 1:1 complexation stoichiometry between crown ethers and N-heteroaromatic cations. Crystal structures of crown ether complexes showed that hydrogen bonding and to a lesser degree cation-π and π-π interactions stabilize the structures in solid state. The values of stability constants for crown ether complexes with N-heteroaromatic cations and purinium cation varied between 10 and 350 M-1. Stability constants were higher for complexes with six-membered N-heteroaromatic cations and purinium cation than for complexes with five-membered cations. The values indicated that hydrogen bonding was the main interaction in solution. Tetraphenylborate formed complexes with four N-heteroaromatic cations and tropylium cation, and reacted with six N-heteroaromatic cations through the displacement of one phenyl group by N-heterocycle to form triphenylboranes. The complexes and displacement products were characterized by 1H NMR spectrometry. Four crystal structures of complexes and three crystal structures of displacement products were resolved. Stability constants of complexes were measured in methanol/acetonitrile (1:1) solution at 30 °C by 1H NMR titration method. The values of stability constants for tetraphenylborate complexes with N-heteroaromatic cations ranged from 10 to 50 M-1. C-H···π and N-H···π interactions were found to stabilize the structures both in solid state and in solution.

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31

Hausner, Sven H. "Part I: Dibenzotetraaza Crown Ethers. Part II: Synthesis and Characterization of Chlorophenyplumbates". University of Cincinnati / OhioLINK, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=ucin998489402.

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32

Bheda, Mukesh C. "Synthesis and characterization of novel molecular architectures : polyrotaxanes and catenanes /". Diss., This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-05222007-091350/.

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33

Engen, Paul Todd. "Novel polymer architectures : polyrotaxanes /". Diss., This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-07282008-134515/.

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34

Han, Dong. "Synthesis of Crown Ether/Ammonium Salt for Electron Transfer Study". Thesis, University of North Texas, 2002. https://digital.library.unt.edu/ark:/67531/metadc3141/.

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The theoretical model of Beratan and Onuchic predicts a large attenuation of ET rates through hydrogen bonds; however, the effect of individual hydrogen bond on electron transfer reaction has not been systematically studied. The organic complexes in this study are a series of crown ether/ammonium salt, which incorporate a redox partner on each component of the complex. The dimethoxynaphthalene redox donor was attached to the crown ether and a series of ammonium salts was synthesized which bear substituted quinone and naphthoquinone acceptor. The complexes characterization and preliminary electron transfer rate measurement were completed with UV/Vis and steady-state emission spectroscopy.

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35

Poola, Bhaskar. "Synthesis and characterization of quinoxaline-functionalized, cage-annulated oxa- and thiacrown ethers and reaction chemistry of the diphosphine ligand 2,3-bis(diphenylphosphino)-N-p-tolylmaleimide (bmi) at triosmium carbonyl clusters". Thesis, University of North Texas, 2006. https://digital.library.unt.edu/ark:/67531/metadc5608/.

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Quinoxaline-functionalized, cage-annulated oxa- and thiacrown ethers have been synthesized as possible specific metal host systems. The synthesis and characterization of quinoxaline-functionalized, cage-annulated oxa- and thiacrown ethers have been described. The characterization of these host systems have been fully achieved in solution by using various techniques such as IR, 1H NMR, and 13C NMR spectroscopic methods, high-resolution mass spectrometry (HRMS), elemental microanalysis, and X-ray crystallographic analysis in case of one quinoxaline-functionalized, cage-annulated oxacrown ether compound. The synthesis of the diphosphine ligand 2,3-bis(diphenylphosphino)-N-p-tolylmaleimide (bmi) is described. The substitution of the MeCN ligands in the activated cluster 1,2-Os3(CO)10(MeCN)2 by the diphosphine ligand bmi proceeds rapidly at room temperature to furnish a mixture of bridging and chelating Os3(CO)10(bmi) isomers and the ortho-metalated product HOs3(CO)9[μ-(PPh2)C=C{PPh(C6H4)}C(O)N(tolyl-p)C(O)]. Thermolysis of the bridging isomer 1,2-Os3(CO)10(bmi) under mild conditions gives the chelating isomer 1,1-Os3(CO)10(bmi), whose molecular structure has been determined by X-ray crystallography. The kinetics for the ligand isomerization have been investigated by UV-vis and 1H NMR spectroscopy in toluene solution over the temperature range of 318-348 K. On the basis of kinetic data conducted in the presence of added CO and the Eyring activation parameters, a non-dissociative phosphine migration across one of the Os-Os bonds is proposed. Orthometalation of one of the phenyl groups associated with the bmi ligand is triggered by near-UV photolysis of the chelating cluster 1,1- Os3(CO)10(bmi).

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36

Qian, Weiguang. "A preliminary investigation of solid sampling for mass spectrometric analysis of crown ethers". Virtual Press, 1987. http://liblink.bsu.edu/uhtbin/catkey/490218.

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The purpose of this study was to optimize and investigate crown ether analysis by using a mass spectrometer equipped with a direct insertion solids probe. The typical aliphatic and aromatic crowm ethers, 18-crown-6 and dibenzo-18-crown-6 were chosen for the study. The crown ether samples were prepared by miximg with the reagents (some inorganic and organic salts and glycine) or being supported on the support materials (diatomite and glass supports) in a 1:10 ratio by weight as the samples for testing. The pure crown ethers and their mixtures were tested by the programmed temperature direct insertion probe mass spectrometer. The effects of the reagents and support materials on the peak maximum temperature (Tm) and the spectra of the crown ethers were studied. The results Tm of the crown ethers to increase significantly, and glycine and ammonium salts interfered the spectra of the crown ethers. The effect of sample size and "concentration" on Tm of the crowns also was investigated. The bigger sample size caused the Tm to be higher. No significant effect of the "concentration" on Tm was observed. It was concluded that tha smaller sample size provided better spectra with less interfererences and that some thermally stable reagents or support materials could be used to facilitate the sampling of crown ethers. More detailed study of the effects of iodides on Tm was recommended. In addition, more detailed investigation of the approach of using a CI source without reagent gases is needed. Switching to the CI configuration appears to be a simple and effective method for providing complementary information about the molecules.Ball State UniversityMuncie, IN 47306

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37

Saunders, Graham Charles. "Redox-active transition metal compounds containing crown ethers as ligands and related studies". Thesis, University of Oxford, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.253407.

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38

Leeson, Philip. "Computer modelling of calixerene compounds capable of selectively extracting lanthanide metals from nuclear waste slurries". Thesis, University of Reading, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.484312.

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39

Mbadike, Okey Patrick. "The preparation and study of new metal binding reagents". Virtual Press, 1990. http://liblink.bsu.edu/uhtbin/catkey/722440.

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New phosphine ligands which also contained crown ether groups were synthesized by condensing two main reagents. Reagent A was Ph2P(CH2)3NH2 and it was prepared by reductingPh2P(CH2)2CN with LiALH4 in diethyl ether. Ph2P(CH2)2CN is obtained by reacting Ph2PH and CH2=C(H)CN in a Michael-type reaction. Reagent B, 4-formyl-benzo-15-crown-5, was obtained from the reaction of 3,4 dihydroxybenzaldehyde with 1,11 dichloro-3,6,9 trioxoundecane.By condensing the benzaldehyde crown ether and the phosphine amine, a Schiff-base type crown ether containing both P(III) and N(III) centers was obtained. Spectroscopic studies of the ligand and its Pd(II) derivative have shown PdCl2[Ph2P.(CH2)3N CH-C6H3(OMe)2]2 were characterized by that metal binding occurred exclusively on the P( III) center.A model ligand was synthesized by condensing 3,4-dimethoxybenzaldehyde with Ph2P(CH2)3NH2 to obtain an analogous product. Both ligands, Ph2P(CH2)3N=CH-benzo-15crown-5 and Ph2P(CH2)3N=CH -C6H3(OMe)2 and their palladium derivatives, PdCl2[Ph2P(CH2)3N=CH-benzo-15-crown-5]2 and spectroscopic and elemental analysis. The Pd(II) derivatives were synthesized from the reactions of (Ph2CN)2)PdC12 with the ligands.
Department of Chemistry

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40

Cooper, Paul J. "Ligands for the coordination of lead". Thesis, University of Bath, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336265.

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41

Patel, Hitesh Kumar. "Studies towards synthetic receptors for small peptides". Thesis, University of Southampton, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240948.

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42

McKim, Artie S. "Synthesis and Alkali Metal Extraction Properties of Novel Cage-Functionalized Crown Coronands and Cryptands". Thesis, University of North Texas, 1999. https://digital.library.unt.edu/ark:/67531/metadc277666/.

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43

Shen, Ya Xi. "New polymer architectures : synthesis and characterization of polyurethane-crown ether based polyrotaxanes /". Diss., This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-02052007-081239/.

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44

Bryant, William Stephen. "Self-Assembly: Synthesis and Complexation of Crown Ethers and Cryptands with R2-NH2 Ions". Diss., Virginia Tech, 1999. http://hdl.handle.net/10919/77980.

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The focus of the following research was to use the self-assembly process to create rotaxanes between several large bisphenylene crown ethers (> 22 atoms) with secondary ammonium salts. Also of great interest was to understand the complexation behavior of the crown ethers with the salts, with emphasis on determining the stoichiometries and association constants of the complexations in solution using NMR spectroscopy. The stoichiometry of the complexes was determined by the mole ratio method and the association constants were calculated graphically. Bis-(m-phenylene)-26-crown-8 did not form a complex in solution with several secondary ammonium salts even though the cavity size is large enough to allow the formation of pseudorotaxanes. However, the larger crown ether, bis-(m-phenylene)-32-crown-10 (BMP32C10), did form a complex. The complex stoichiometry varied between 1:1 (crown:salt) in solution and 1:2 in the solid state as evidenced by NMR and X-ray crystallography, respectively. The solid state complexes were pseudorotaxanes. Also, an interesting "exo" complex was formed in the solid state between BMP32C10 and a secondary diammonium salt. The major binding force for the complexes in the X-ray structures was hydrogen bonding. Weaker secondary stabilization was achieved via aryl-aryl aromatic interactions. The difference between the stoichiometries in the two phases and the observance of an "exo" complex demonstrates that one must be careful in describing the complexes in each phase. Also investigated was the complexation formed between dibenzo-24-crown-8 (DB24C8) and secondary diammonium salts. The association constants for the complexes were found to be relatively higher. Due to the weaker association constants and the different stoichiometries of complexation the meta-susbtituted bisphenylene crown ethers were not recommended for the formation of larger complexes, i.e. polyrotaxanes. However, it is suggested that the DB24C8 moiety be used in components of supramolecular assemblies. The functionalization of poly(propylene imine) dendrimers with two different crown ethers as peripheral moieties was attempted. The 1st, 3rd, and 5th generation poly(propylene imine) dendrimers were functionalized with 1,3-phenylene-16-crown-5 moieties by reacting the surface primary amines with the corresponding succinimide ester of the crown ether. The larger DB24C8 succinimide ester was not as reactive and full functionalization was not achieved.
Ph. D.

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45

陳淑恆 e Suk-hang Chan. "Synthesis of diazacrown ether and transition metal containing polymersby atom transfer radical polymerization and other methods". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B3124287X.

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46

Nkansah, Shadrack Osei. "Electrospray mass spectrometry : an investigation of non- covalent interactions of histone/crown ether complexes and applied methods of computational chemistry". Virtual Press, 1996. http://liblink.bsu.edu/uhtbin/catkey/1014849.

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The focus of this research is to combine both computational as well as experimental methods to study the non-covalent interaction between a selected set of proteins with small molecules. Experimentally, a mass spectrometric technique, recently known as electrospray mass spectrometry together with the computational aspect of this research, in the area of molecular modeling and quantum mechanics would be exercised.Due to the soft ionization nature of this process, electrospray (ES) mass spectrometry (MS) has been employed to study a broad class of large proteins and their non-covalent interaction with small structures, making it possible for the mass of these complexes to _be determined with an error of less than 0.1%. For this research, a set of proteins known as histones and a class of structures known as crown ethers were chosen. The ES technique allows the proteins to be prepared in an acidic medium that protonates the basic amino acids that have been exposed by the solvent. This process leaves the protein with a lot of positive charges thereby making the analysis with a single quadrupole mass spectrometer, Extrel ELQ 400 possible. The non-covalent complexation between the histones and the crown ethers is stabilized by hydrogen bonding therefore the positive charges of the protein remain unchanged. This bonding is made possible by the ability of crown ethers to bind ammonium ion or protonated amino groups. The mass of the protein which is divided by the number of its positive charges can be determined by a new kind of linear plot constructed from the ES data. The ion currents from the electrospray ionization technique is a representation of the non-covalent complexation of the histones and the crown ethers which can be observed in the mass spectra. Other information such as, the binding constants, can be obtained from the mass spectra.
Department of Chemistry

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47

Sheu, Biing-Jahn. "The synthesis and characterization by use of spectroscopic and x- ray methods of bromo, phosphine, and nitro derivatives of 13-phenyl- 1,4,7,10-tetraoxa-13-azacyclopentadecane". Virtual Press, 1992. http://liblink.bsu.edu/uhtbin/catkey/834528.

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The phenyl ring in the crown ether, 13-phenyl-1,4,7,10-tetraoxa-13-azacyclopentadecane (I), was used a site for functionalizing the compound. Electrophilic bromination of the ring with tribromide ion gave a 95% yield of the product substituted in the para position. This product underwent lithium-bromine exchange when reacted with n-butyllithium. The resulting anion was used to prepare PhZPX and PhPX2 derivatives, X p-C6H4NCH2(CH2OCH2)4&12 The oxide of PhZPX was completely characterized by an x-ray diffraction study which showed, in general, that the phosphorus was tetrahedral, the nitrogen planar, and the crown ether ring organized with the oxygen atoms endodentate. Several attemps were made to nitrate or nitrosate the phenyl ring in the parent crown ether. Spectroscopic evidence obtained from the products indicate that the reaction led to mixtures of mono and disubstituted products.
Department of Chemistry

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48

Clapham, Bruce. "Scintillation counting in molecular recognition and combinatorial chemistry". Thesis, Nottingham Trent University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298841.

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49

Chan, Suk-hang. "Synthesis of diazacrown ether and transition metal containing polymers by atom transfer radical polymerization and other methods /". Hong Kong : University of Hong Kong, 2002. http://sunzi.lib.hku.hk/hkuto/record.jsp?B25212102.

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50

Haddadian, Fereshteh. "The synthesis and characterization of phosphine functionalized crown ethers by use of spectroscopic and x-ray methods". Virtual Press, 1995. http://liblink.bsu.edu/uhtbin/catkey/958795.

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The phosphine(III) crown ethers, [4'-(N-phenylaza-15crown-5)]3P (1), [4'-(N-phenylaza-l8-crown-6)]3P (2), [4'-(Naza-18-crown-6)]2-Ph-P (3), and [4'-(benzo-15-crown-5)]3P (4) were synthesized by using an electrophilic bromination of the crown phenyl ring (with a tribromide ion) followed by the preparation of a lithium salt and subsequent reaction of the resulting lithiocrowns with P(III) reagents. The oxide of compound 1 was completely characterized by an X-ray diffraction study, which showed that structurally there is not a significant difference in P-O bond distances and OPC bond angles with [4'-(N-phenylaza-15-crown-5)]-Ph2-P=O. Thespectroscopic data of compound 1 and 2 were compared. It appears that 1 and 2 are similar in P environment; also they are more air sensitive than 3 and 4. In addition, a discussion about compounds 1-4, and a literature review of the preparation of phosphines are included.
Department of Chemistry

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