Purpose The purpose of the paper is to explain how executives can make effective use of fables provided by external guest speakers to create a situation of collective sense-making and centring, based on the story used in a policy making context of a private, Dutch for-profit organization ( fictitiously called Con-Zelo recruitment agency in this article ).   Design/methodology/approach The approach involved collecting and analyzing the ‘Swimming for gold’ fable as part of seven months phenomenological and symbolic study, to confirm organizational sense, identify categorized themes and analyze the process of creation. In which co-author Volkers, as a former member, had access to the organization and familiarity with the organization its history.   Findings The findings emphasize that both fables and myths can in fact establish organizational sense and centring based on categorized themes. Most important is that fables shared by an external guest speaker should not be considered as a singular event, but as start of a process; a true vehicle for collective sense-making and centring. Organizations can then do so through changes and alignment in all five types of cultural artifacts.   Originality/value This paper provides additional value by bridging the gap between theory and practice. Besides illustrating that fables do in fact contain the power to promote a particular point of view, specific meaning and or values and therewith establish organizational sense and centring. This study includes the documentation and cultural analysis of the fable, and illustrates the fable as a vehicle or process for collective sense-making and centring. Furthermore, the suggested fable-stretching model is a so called ‘soup-to-nuts’ approach that can serve as a blue-print for organizational researchers and change agents interested in using external guest speakers and the personal fables they carry out, to establish collective sense-making and centring within an organizational context.

Metal organic framework (MOF) has emerged as a new class of porous, thermally stable material which has attracted great attention due to their wide applications in gas storage, separation, catalysis etc. Self-assembly is the operative mechanism of MOFs syntheses; however, the control of MOF self-assembly is still a challenge in the construction of predetermined, structurally well-defined MOFs. The goal of the research is to arrive at multidimensional, highly porous and functional MOFs via hierarchical assembly of smaller molecular building blocks and, at the same time, to examine the possibilities for different interesting molecular textures. This goal is to be accomplished by the knowledge of ligand coordination mode, and geometry as well as logical choices of ligands and metals from which the MOFs are to be constructed from. Preparations of novel frameworks as well as other interesting molecular architectures are highlighted with their structures characterized.

Metal organic framework (MOF) has emerged as a new class of porous, thermally stable material which has attracted great attention due to their wide applications in gas storage, separation, catalysis etc. Self-assembly is the operative mechanism of MOFs syntheses; however, the control of MOF self-assembly is still a challenge in the construction of predetermined, structurally well-defined MOFs. The goal of the research is to arrive at multidimensional, highly porous and functional MOFs via hierarchical assembly of smaller molecular building blocks and, at the same time, to examine the possibilities for different interesting molecular textures. This goal is to be accomplished by the knowledge of ligand coordination mode, and geometry as well as logical choices of ligands and metals from which the MOFs are to be constructed from. Preparations of novel frameworks as well as other interesting molecular architectures are highlighted with their structures characterized.

<p>This work examines the characterization of supramolecular assemblies and, more specifically, host-guest complexes involved in molecular recognition events. The supramolecular assemblies studied take root from metal ion delivery in biological uptake pathways, specifically the delivery of iron to microbial cells. These assemblies are studied in an effort to further understand the nature of molecular recognition events, specifically the nature and strength of interactions between a host and a guest, and possible applications of these systems. </p> <p>The development of a mass spectral method by which to characterize supramolecular assemblies involving the cation binding hosts 18-crown-6, benzo-18-crown-6, dicyclohexano-18-crown-6, and dibenzo-18-crown-6 macrocycles, and the linear ionophore lasalocid with cationic guests, including substituted protonated amines and the iron siderophore ferrioxamine B is presented. Methodology was developed using ESI-MS to successfully quantitate host-guest interactions in binary and complex mixtures. Binding constants were obtained in the range of log Ka = 3 - 5 and correspond to similar systems previously studied in the literature. The studies presented here further our understanding of the molecular recognition events that must occur between a siderophore and a receptor and provide an improved method by which to measure the strength of their interaction. </p> <p>The effects of redox hosts on host-guest complex formation with ferrioxamine B and the characterization of the host-guest complexes formed and the strength of the interactions between them were studied using cyclic voltammetry, ESI-MS, FAB-MS and ITC. A shift in redox potential towards more positive values is observed upon addition of a cationic siderophore guest to a solution of a redox-active para-Wurster's aza crown or mono-substituted Wurster's aza crown macrocycle. Mass spectral evidence indicates the formation of a host-guest complex between the cationic siderophore and the redox host. A redox switch mechanism is proposed, whereby the redox state of the host influences the binding affinity between the host and guest and, consequently, host-guest complex formation. These systems offer a unique means by which to modulate the uptake or release of ionic guests from a cavity by using externally controlled methods and can be applied to selective metal ion compartmentalization. </p> <p>Finally, the application of supramolecular assemblies as a tool in the field of drug delivery is presented. The covalent attachment of an antimalarial drug, artemisinin, by our collaborators to a siderophore produced by M. Tuberculosis, mycobactin, facilitates the subsequent delivery of the drug into the microbial cell by taking advantage of the natural biological iron uptake pathway. Here, the molecular recognition event and supramolecular assembly of interest is that occurring between the siderophore-drug assembly and the microbial receptor. Characterization of the siderophore-drug assembly using cyclic voltammetry shows that there is an interaction between the Fe-mycobactin and artemisinin when these are covalently attached in the form of a conjugate. Increased current output is observed due to an intramolecular electron transfer between the two components. Based on these in vitro data, we propose a redox mechanism by which the drug-siderophore conjugate exhibits a therapeutic effect in vivo.</p> / Dissertation

The laser-induced molecular reorientation effect of guest-host dye-doped liquid crystals in isotropic phase has been studied by measuring the signals of optical Kerr effect using pulsed frequency-doubling Nd:YAG laser as a pumping source. The critical behavior near the isotropic-nematic transition has been observed when the temperature approaches to the phase transition of liquid crystal. The relaxation time constant is about several hundreds of ns as the temperature is far above the clearing point of liquid crystals and that is longer than 1500 ns as the temperature is close to the clearing point of liquid crystals. According to Landau¡¦s second phase transition theory, the interaction between liquid crystal molecules will be increased and the nonlinearity effect of liquid crystal will be enhanced when the temperature is near the clearing point of liquid crystal. The relaxation time constant of molecular reorientation is a function of viscosity and temperature of liquid crystal, the relationship can be fitted as£b0*exp(f/T)*(1/T-T*),where £b0 is the viscosity coefficient and T* is the clearing point of the sample. The optical Kerr signal is found to be proportional to the energy density of pumping source. The optical Kerr signal can be sustained as long as 20£gs when the energy density of pumping source reaches to 1J/cm sq. The enhancement of molecular reorientation effect is also observed by increasing the concentration of dye.

Previously we have suggested the concept of tuning hydrate compositions which makes it possible to increase the gas storage capacity of binary hydrates. Herein, we report for the first time the existence of a critical guest concentration (CGC) and establish the complete tuning pattern that appears to exist in binary hydrates, including the water-soluble hydrate formers (promoters) and water insoluble guests,. The first attempt to verify the new features of clathrate hydrate compositions is executed on the binary hydrate of CH4 + THF and involves a detailed examination of the guest distribution by spectroscopic methods. THF molecules by themselves form sII hydrate from a completely miscible aqueous solution, and in this structure, because of their size, THF molecules occupy only the large 51264 cages. The CGC value appears to depend largely on the chemical nature of the liquid guest component participating in the binary hydrate formation. The present experimental findings on the existence of critical guest concentration and the complete tuning phenomenon can be expected to make a meaningful contribution to both inclusion chemistry and a variety of hydrate-based fields.

La presente tesis consta de dos vertientes interrelacionadas. La primera se centra en intentar cuantificar experimentalmente la contribución energética en disolución de la interacción anión-&#61552;, mediante el uso de calix[4]pirroles aril substituidos en las posiciones meso- como moléculas modelo. El trabajo realizado muestra que la interacción anión-&#61552; es repulsiva para anillos con valores de ESP negativos y a medida que el efecto electrón atrayente de los sustituyentes aumenta la interacción se vuelve menos repulsiva, hasta que, cuando el valor de ESP en el centro del anillo aromático es positivo la interacción se vuelve ligeramente atractiva. La segunda en el uso de estos receptores simples para obtener arquitecturas supramoleculares más complejas, y su autoensamblaje en capsulas. Los estudios muestran que calix[4]pirroles sustituidos con grupos urea en sus anillos aromáticos se autoemsamblan en capsulas diméricas en presencia de un huesped adecuado como los N-óxidos de alquil aminas y piridinas en disolventes apolares. / This thesis consists of two interrelated aspects. The first one pretends to quantify experimentally the energetic contribution in solution of the anion-&#61552; interaction, using aryl extended calix[4] pyrroles substituted in their meso- positions as a model system. The work performed shows that the anion-&#61552; interaction is repulsive for aromatic rings with negative ESP values, as the electron withdrawing character of the substituent increases the interaction becomes less repulsive, until eventually, when the ESP value in the center of the aromatic ring is positive the interaction turns into slightly attractive.The second one is based on the use of these simple receptors as scaffolds to obtain complex structures and their self-assembly into capsules. The studies performed show that aryl extended calix[4]pyrroles substituted with urea functions on their upper rim self-assemble into dimeric capsules in the presence of a suitable guest like the N-oxides of alkyl amines and pyridines in non-polar solvents.

This thesis describes the host-guest chemistry between cucurbit[7]uril (CB[7]) and various series of guests, including neutral polar organic solvents, bis(pyridinium)alkane dications, local anaesthetics, acetylcholine analogues, as well as succinylcholine and decamethonium analogues, in aqueous solution. A focus of this thesis is the effects of varying the chemical structures within different series of guests upon the nature of the host-guest chemistry, such as the relative position and orientation of the guest relative to the CB[7] cavity, and the strengths of the binding affinities. The binding affinities of polar organic solvents with CB[7] depend upon the hydrophobic effect and dipole-quadrupole interactions. The polar guests align themselves so that their dipole moment is perpendicular to the quadrupole moment of CB[7]. The binding strengths of acetone and acetophenone to CB[7] decrease in the presence of alkali metals. Discrete 1:1 and 2:1 host-guest complexes are formed between CB[7] and a series of bis(pyridinium)alkane guests. In most cases the CB[7] initially occupies the aliphatic linker when the 1:1 complex is formed and migrates to the terminal regions as the second CB[7] is added. When bulky, hydrophobic tert-butyl substituents are present, however, the CB[7] occupies the terminal pyridinium region and not the central linker. Supramolecular complexes between CB[7] and a series of local anaesthetics have binding affinities 2-3 orders of magnitude greater than reported values with beta-cyclodextrin. The first pKa values of the guests increase by 0.5-1.9 units upon complexation. The binding positions of the guests within CB[7] differ in neutral and acidic media, with the systems thus behaving as pH-activated switches. With supramolecular complexes between CB[7] and various cationic cholines and their phosphonium analogues, the CB[7] cavity is occupied by the charge-diffuse cationic region. The binding affinities and positions vary depending on the nature of the onium group as well as the substituents within the guest molecule. Host-guest complexes between CB[7] and dicationic acetylcholinesterase inhibitors have very strong 1:1 binding affinities, with 2:1 binding being significantly weaker. These binding affinities are related to the nature of the cationic onium groups, and the length and hydrophobicity of the connecting linkers. / Thesis (Ph.D, Chemistry) -- Queen's University, 2010-01-28 12:27:37.833

A series of five linked β-cyclodextrin (βCD) dimers N,N-bis(6 [superscript]A-deoxy-6[superscript]A-β-cyclodextrinyl)-succinamide, 66βCD₂su, N-((2[superscript]A S,3 [superscript]A S)-3 [superscript]A-deoxy-3 [superscript]A-β-cyclodextrinyl)-N’-(6 [superscript]A-deoxy-6 [superscript]A -β-cyclodextrinyl)-urea, 36βCD₂su, N,N-bis((2 [superscript]A S,3 [superscript]A S)-3 [superscript]A -deoxy-3 [superscript]A-β-cyclodextrinyl)-succinamide, 33βCD₂su, N,N-bis(6[superscript]A-deoxy-6[superscript]A-β-cyclodextrinyl)-urea, 66βCD₂ur, and N-((2 [superscript]A S,3 [superscript]A S)-3 [superscript]A-deoxy-3 [superscript]A-β-cyclodextrinyl)-N’-(6 [superscript]A -deoxy-6 [superscript]A -β-cyclodextrinyl)urea, 36βCD₂ur, has been prepared. The complexation of 6-(4’-(toluidinyl)naphthalene-2-sulphonate, TNS⁻, by βCD and the five linked βCD dimers was characterized by UV, fluorescence and 2D ¹H ROESY NMR spectroscopy. In aqueous phosphate buffer at pH 7.0, I = 0.10 mol dm⁻³ and 298.2 K, TNS⁻ forms host-guest complexes with βCD of stoichiometry βCD.TNS⁻ (K₁ = 3020 and 3320 dm³ mol⁻¹) and βCD₂.TNS⁻ (K₂ = 57 and 11 dm³ mol⁻¹) where the first and second values were determined in UV and fluorescence studies, respectively. For 66βCD₂su, 36βCD₂su, 33βCD₂su, 66βCD₂ur and 36βCD₂ur, the analogous K₁ = 16100, 10900, 10700, 55100 and 18300 dm³ mol⁻¹ and K₁ = 12500, 8700, 9600, 38000 and 9800 dm³ mol⁻¹(fluorimetric studies), respectively. ¹H 2D ROESY NMR studies provided evidence for variation of the mode of complexation of the TNS⁻ guest as the βCD host is changed. The factors affecting complexation are discussed. UV and ¹H NMR studies showed that 6-(4’-(t-butyl)-phenyl)naphthalene-2-sulphonate, BNS⁻, and its dimer, (BNS⁻)₂, form host-guest complexes with βCD of the stoichiometry βCD.BNS⁻ (K₁ = 5.54 × 10⁴ dm³ mol⁻¹ ) and βCD.BNS₂ ²⁻(K₂ = 3.07 × 10² dm³ mol⁻¹ ) where the complexation constant K₁ = [βCD.BNS⁻]/([βCD][BNS⁻] and K₂ = [βCD.(BNS⁻)₂]/([βCD.BNS⁻][BNS⁻]) in aqueous phosphate buffer at pH 7.0, I = 0.10 mol dm⁻³ and 298.2 K. For 66βCD₂su, 36βCD₂su, 33βCD₂su, 66βCD₂ur and 36βCD₂ur the analogous K₁ = 125, 74, 10.2, 364 and 16.1 (× 10⁴ dm³ mol⁻¹ ) and K₂ = 25.7, 2.30, 2.57, 17.6 and 17.2 (× 10² dm³ mol⁻¹ ), respectively. For the dimerisation of BNS⁻ K[subscript]d = 2.63 × 10² dm³ mol⁻¹ . Fluorimetric studies showed that the complexation stability for βCD.BNS⁻, forms βCD. BNS⁻, 66βCD₂su.BNS⁻, 36βCD₂su.BNS⁻, 33βCD₂su. BNS⁻, 66βCD₂ur.BNS⁻ and 36βCD₂ur. BNS⁻ characterized by K₁ = 4.67, 330, 101, 11.0, 435 and 29.6 (× 10⁴ dm³ mol⁻¹ ), respectively. The factors affecting the variations in these data are discussed. The enantioselectivity of substituted βCDs 6 [superscript]A -[bis (carboxylatomethyl)amino]-6 [superscript]A -deoxy-β-cyclodextrin (6βCDidaH₂) and (2 [superscript]A S,3 [superscript]A S)-3 [superscript]A -[bis(carboxylatomethyl)amino]-3[superscript]A -deoxy-β-cyclodextrin (3βCDidaH₂) and 6 [superscript]A -[tris(carboxylatomethyl)(2- aminoethyl)amino]-6 [superscript]A -deoxy-β-cyclodextrin (6βCDedtaH₃) and their Eu³ ⁺ complexes in forming host-guest complexes with six enantiomeric guests in D₂O was studied by 1D and 2D ¹H NMR (600 MHz) spectroscopy. The guests are D/L-tryptophanate (Trp⁻), 4-hydroxyl-D/L-phenylglycinate (4HOPhg⁻), D/L-histidinate (His⁻), D/L-pheniramine (Phm), D/L-phenylglycinate (Phg⁻) and (D/L)-β-phenylserinate (βPhs⁻). Enantioselective host-guest complexation was observed between the [Eu(6βCDida)]⁺ , [Eu(3βCDida)]⁺ and [Eu(6βCDedta)] complexes and Trp⁻, [Eu(6βCDida)]⁺ and [Eu(3βCDida)]⁺ and 4HOPhg⁻, and βCD, 6βCDida²⁻, 3βCDida²⁻, 6βCDedta³⁻ and the Eu³⁺complexes of the three substituted βCDs and Phm. The His⁻, Phg⁻ and βPhs⁻ enantiomers showed no evidence for selective host-guest complexation. The preparation of 3βCDidaH₂ and 6βCDedtaH₃ and the determination of their pK[subscript]a s are also reported. In collaboration with the research group of Prof. Matthew A. Tarr, (University of New Orleans, USA), the 6βCDida²⁻ and the 6βCDedta³⁻ has been utilized to improve Fenton oxidation of aromatic pollutants. To further support to this work, the binary complexation of Fe² ⁺ by 6βCDida²⁻ has been studied by potentiometric titrations. A series of six modified poly(acrylic acid)s 3% substituted with either βCD or the adamantyl moiety with different length of substituent chain was synthesised. To advance the understanding and control of aqueous supramolecular assembly, the host-guest interactions between the βCD substituted poly(acrylic acid)s and adamantane-1-carboxylic; adamantyl substituted poly(acrylic acid)s with βCD and linked βCD dimers; and between both βCD and adamantyl substituted poly(acrylic acid)s have been studied. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1311237 / Thesis (Ph.D.) -- University of Adelaide, School of Chemistry and Physics, 2008

A series of five linked β-cyclodextrin (βCD) dimers N,N-bis(6 [superscript]A-deoxy-6[superscript]A-β-cyclodextrinyl)-succinamide, 66βCD₂su, N-((2[superscript]A S,3 [superscript]A S)-3 [superscript]A-deoxy-3 [superscript]A-β-cyclodextrinyl)-N’-(6 [superscript]A-deoxy-6 [superscript]A -β-cyclodextrinyl)-urea, 36βCD₂su, N,N-bis((2 [superscript]A S,3 [superscript]A S)-3 [superscript]A -deoxy-3 [superscript]A-β-cyclodextrinyl)-succinamide, 33βCD₂su, N,N-bis(6[superscript]A-deoxy-6[superscript]A-β-cyclodextrinyl)-urea, 66βCD₂ur, and N-((2 [superscript]A S,3 [superscript]A S)-3 [superscript]A-deoxy-3 [superscript]A-β-cyclodextrinyl)-N’-(6 [superscript]A -deoxy-6 [superscript]A -β-cyclodextrinyl)urea, 36βCD₂ur, has been prepared. The complexation of 6-(4’-(toluidinyl)naphthalene-2-sulphonate, TNS⁻, by βCD and the five linked βCD dimers was characterized by UV, fluorescence and 2D ¹H ROESY NMR spectroscopy. In aqueous phosphate buffer at pH 7.0, I = 0.10 mol dm⁻³ and 298.2 K, TNS⁻ forms host-guest complexes with βCD of stoichiometry βCD.TNS⁻ (K₁ = 3020 and 3320 dm³ mol⁻¹) and βCD₂.TNS⁻ (K₂ = 57 and 11 dm³ mol⁻¹) where the first and second values were determined in UV and fluorescence studies, respectively. For 66βCD₂su, 36βCD₂su, 33βCD₂su, 66βCD₂ur and 36βCD₂ur, the analogous K₁ = 16100, 10900, 10700, 55100 and 18300 dm³ mol⁻¹ and K₁ = 12500, 8700, 9600, 38000 and 9800 dm³ mol⁻¹(fluorimetric studies), respectively. ¹H 2D ROESY NMR studies provided evidence for variation of the mode of complexation of the TNS⁻ guest as the βCD host is changed. The factors affecting complexation are discussed. UV and ¹H NMR studies showed that 6-(4’-(t-butyl)-phenyl)naphthalene-2-sulphonate, BNS⁻, and its dimer, (BNS⁻)₂, form host-guest complexes with βCD of the stoichiometry βCD.BNS⁻ (K₁ = 5.54 × 10⁴ dm³ mol⁻¹ ) and βCD.BNS₂ ²⁻(K₂ = 3.07 × 10² dm³ mol⁻¹ ) where the complexation constant K₁ = [βCD.BNS⁻]/([βCD][BNS⁻] and K₂ = [βCD.(BNS⁻)₂]/([βCD.BNS⁻][BNS⁻]) in aqueous phosphate buffer at pH 7.0, I = 0.10 mol dm⁻³ and 298.2 K. For 66βCD₂su, 36βCD₂su, 33βCD₂su, 66βCD₂ur and 36βCD₂ur the analogous K₁ = 125, 74, 10.2, 364 and 16.1 (× 10⁴ dm³ mol⁻¹ ) and K₂ = 25.7, 2.30, 2.57, 17.6 and 17.2 (× 10² dm³ mol⁻¹ ), respectively. For the dimerisation of BNS⁻ K[subscript]d = 2.63 × 10² dm³ mol⁻¹ . Fluorimetric studies showed that the complexation stability for βCD.BNS⁻, forms βCD. BNS⁻, 66βCD₂su.BNS⁻, 36βCD₂su.BNS⁻, 33βCD₂su. BNS⁻, 66βCD₂ur.BNS⁻ and 36βCD₂ur. BNS⁻ characterized by K₁ = 4.67, 330, 101, 11.0, 435 and 29.6 (× 10⁴ dm³ mol⁻¹ ), respectively. The factors affecting the variations in these data are discussed. The enantioselectivity of substituted βCDs 6 [superscript]A -[bis (carboxylatomethyl)amino]-6 [superscript]A -deoxy-β-cyclodextrin (6βCDidaH₂) and (2 [superscript]A S,3 [superscript]A S)-3 [superscript]A -[bis(carboxylatomethyl)amino]-3[superscript]A -deoxy-β-cyclodextrin (3βCDidaH₂) and 6 [superscript]A -[tris(carboxylatomethyl)(2- aminoethyl)amino]-6 [superscript]A -deoxy-β-cyclodextrin (6βCDedtaH₃) and their Eu³ ⁺ complexes in forming host-guest complexes with six enantiomeric guests in D₂O was studied by 1D and 2D ¹H NMR (600 MHz) spectroscopy. The guests are D/L-tryptophanate (Trp⁻), 4-hydroxyl-D/L-phenylglycinate (4HOPhg⁻), D/L-histidinate (His⁻), D/L-pheniramine (Phm), D/L-phenylglycinate (Phg⁻) and (D/L)-β-phenylserinate (βPhs⁻). Enantioselective host-guest complexation was observed between the [Eu(6βCDida)]⁺ , [Eu(3βCDida)]⁺ and [Eu(6βCDedta)] complexes and Trp⁻, [Eu(6βCDida)]⁺ and [Eu(3βCDida)]⁺ and 4HOPhg⁻, and βCD, 6βCDida²⁻, 3βCDida²⁻, 6βCDedta³⁻ and the Eu³⁺complexes of the three substituted βCDs and Phm. The His⁻, Phg⁻ and βPhs⁻ enantiomers showed no evidence for selective host-guest complexation. The preparation of 3βCDidaH₂ and 6βCDedtaH₃ and the determination of their pK[subscript]a s are also reported. In collaboration with the research group of Prof. Matthew A. Tarr, (University of New Orleans, USA), the 6βCDida²⁻ and the 6βCDedta³⁻ has been utilized to improve Fenton oxidation of aromatic pollutants. To further support to this work, the binary complexation of Fe² ⁺ by 6βCDida²⁻ has been studied by potentiometric titrations. A series of six modified poly(acrylic acid)s 3% substituted with either βCD or the adamantyl moiety with different length of substituent chain was synthesised. To advance the understanding and control of aqueous supramolecular assembly, the host-guest interactions between the βCD substituted poly(acrylic acid)s and adamantane-1-carboxylic; adamantyl substituted poly(acrylic acid)s with βCD and linked βCD dimers; and between both βCD and adamantyl substituted poly(acrylic acid)s have been studied. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1311237 / Thesis (Ph.D.) -- University of Adelaide, School of Chemistry and Physics, 2008