Gas phase experimental and computational investigations are described for F--H2 and the halide-methane complexes and clusters, F--(CH4)n and Cl--(CH4)n. Vibrational predissociation spectroscopy in conjunction with tandem mass spectrometry are used to obtain mid-infrared spectra of each complex in the ligand’s hydrogen stretch region. Ab initio calculations are used to predict structures, binding energies and vibrational frequencies and intensities. By examining the changes in both the vibrational frequencies and intensities of the neutral moiety upon complexation with the anion, and comparing these with the theoretical predictions, structures are able to be inferred. (For complete abstract open document)

Regensburg, Univ., Diss., 2007

Thesis (Ph. D.)--Florida State University, 2005. / Advisor: Qing-Xiang A. Sang, Florida State University, College of Arts and Sciences, Dept. of Chemistry and Biochemistry. Title and description from dissertation home page (viewed May 11, 2006). Document formatted into pages; contains xvii, 118 pages. Includes bibliographical references.

Th. 3e cycle--Électrochim.--Grenoble--I.N.P., 1982. N°: D3 126.

acase@tulane.edu / Rational, synthetic design is implemented in a systematic study of the effect of host shape and properties and manifestations of the reverse Hofmeister effect. Hofmeister specific effects were observed at the molecular level wherein it was shown that key to the effectiveness of some “salting-in” anions is their complementarity to hydrophobic cavities and other binding surfaces. A gamut of responses was observed across a range of hosts possessing different structural and functional motifs. These observations were typically manifest at a relatively low (<20 mM) critical precipitation concentration (CPC). Furthermore, it was shown that at low concentrations, typical observations of screening effects are not observed, and binding-site competition is a predominant factor when multiple anions are present in solution. In terms of quantifying the ion recognition sites of different, similarly charged hosts there is little difference in anion affinity, but large differences are observed in 1/CPC values. Thus, subtle changes in the recognition site have dramatic changes in terms of manifestations of the reverse Hofmeister effect. This is (to the authors best knowledge) the first example of a systematic study sequentially modifying small molecular hosts and utilizing them to study reverse Hofmeister trends. In total 12 hosts and 6 host-guest complexes were examined. These studies demonstrate applications of the reverse Hofmeister effect to generate single crystal X-ray structures, with potential applications in protein and small molecule purifications, separations, and crystallizations. / 1 / Jacobs Jordan

This dissertation reports on the recent discovery that calix[4]pyrrole not only functions as an anion receptor, but also has the ability to act as an ion pair receptor. It was discovered that in the solid state large diffuse cations, such as Cs+ and imidazolium, will occupy the electron-rich cone-like cavity that is formed upon anion binding to the NH region of the calix[4]pyrrole core. Also discussed are efforts devoted to improving the anion binding ability of calixpyrroles and fine-tuning their inherent selectivity. This has been probed through a variety of structural modifications. One of the most attractive of the modification strategies currently being explored involves expansion of the central binding cavity by using higher order β-fluorinated calix[n]pyrroles; n = 5, 6, and 8. An advantage of β-fluorinated calix[4]pyrrole is that it shows enhanced anion binding affinities toward several anions compared to the parent calix[4]pyrrole. Fluorinated calixpyrroles have also shown an ability to extract anions from aqueous environments into organic media. An alternative strategy has been to attach “straps” resulting in bicyclic systems, which further define the binding cavity achieving higher affinity and anion selectivity. The binding interactions of calixpyrrole and it derivative have been quantified using analytical techniques, such as nuclear magnetic resonance spectroscopy and isothermal titration calorimetry. The results of these latter studies will be discussed herein. / text

This thesis describes the synthesis of acyclic, macrocyclic and, in particular, interlocked anion and ion-pair receptors and sensors. <strong>Chapter One</strong> will introduce the field of supramolecular chemistry with particular emphasis on areas which are pertinent to this thesis, including anion receptor design and templated synthesis of interlocked structures. <strong>Chapter Two</strong> focuses on the synthesis of new heteroditopic macrocycles functionalised with both cation and anion recognition sites and their incorporation into interlocked architectures. The affinity for a range of anions and ion-pairs is explored via ¹H NMR and UV-visible spectroscopy as well as by X-ray crystallography. <strong>Chapter Three</strong> details the incorporation of d- and f-metal luminescent reporter groups into an isophthalamide motif in order to construct acyclic, macrocyclic and [2]rotaxane receptors. <strong>Chapter Four</strong> investigates the synthesis of complex higher-order interlocked structures through post-synthetic modification of lower-order interlocked structures. <strong>Chapter Five</strong> explores the potential for fluorescent gold nanoparticle conjugates to act as luminescent and colourimetric sensors for chemical warfare agents (CWAs) by employing a fluorescent displacement assay technique.

Molecular and cluster anions have been investigated using photoelectron velocity-map imaging spectroscopy to study the nature of electrons in radical species. We report a negative-ion photoelectron imaging study of benzonitrile and several of its hydrated, oxygenated, and homo-molecularly solvated cluster anions. The photodetachment transition from the unsolvated benzonitrile anion to the X̃¹A₁ state of the neutral peaks at 58 ± 5 meV. The electron affinity (EA) of the lowest excited electronic state of benzonitrile, ã³A₁, is determined as 3.41 ± 0.01 eV. The next excited state, the open-shell singlet ùA₁, is found about an electron-volt above the triplet, corresponding to a vertical detachment energy of 4.45 ± 0.01 eV. The step-wise and cumulative solvation energies of benzonitrile anions by several types of species were determined, including homo-molecular solvation by benzonitrile, hydration by 1–3 waters, oxygenation by 1–3 oxygen molecules, and mixed solvation by various combinations of O₂, H₂O, and benzonitrile. Ethylene has been shown to be a degradation product following the 1-e⁻ attachment to ethylene carbonate. As a solvent molecule for (O₂)^(□), our photoelectron imaging study shows a relatively small solvation energy of ≤0.24 eV for the expected 𝜋-𝜋 interaction in the ((O₂)^(□))(C₂H₄) cluster anion. The EA of the O₂(C₂H₄) cluster was measured at 0.69 ± 0.01 eV, while the 𝑋³A″ ← 𝑋²A″ photodetachment transition shows a 1400 ± 100 cm⁻¹ vibrational progression in the 1064 nm spectrum. Negative-ion photoelectron imaging was used to investigate the substituted carbene derivative of fluoroacetonitrile. We report a closed-shell singlet ground state for the cyanofluorocarbene, FCCN, with an adiabatic electron affinity EA = 2.081 ± 0.002 eV and a singlet-triplet gap of ΔEₛ₋ₜ = 0.42 ± 0.04 eV. The open-shell singlet ¹A″ state was also observed experimentally. We find that the experimentally measured ΔEₛ₋ₜ of FCCN agrees well with the general trend of similar carbenes. We report preliminary results on the photoelectron imaging of phenylcarbene, cyanophenylcarbene, and chlorophenylcarbene anions. Triplet phenylcarbene is observed to have an EA of ≤0.83 eV, considerably lower than the previously indirectly-determined value. Transitions to the singlet and triplet ground state of both cyanophenylcarbene and chlorophenylcarbene are observable, though unidentified bands make full assignment difficult. Cyanophenylcarbene is found to have a triplet ground-state, with a tentative EA of 2.04 eV. Chlorophenylcarbene is found to have a singlet ground-state. The phenyl-group is found to favor the singlet state slightly. The cyanofluoromethyl radical, FC(H)CN, was estimated to have an EA of 1.53 ± 0.08 eV, by a combination of experimental and theoretical results.. With similar methodology, we report the adiabatic electron affinity of the cyanobenzyl radical, EA(PhCHCN) = 1.90 ± 0.01 eV, and assign an upper limit of the EA for the chlorobenzyl radical, EA(PhCHCl) ≤ 1.12 eV. These values were used to estimate the C-H bond dissociation energy (BDE)s for these substituted methanes. Fluoroacetonitrile was found to have a BDE of D𝐻₁₉₈ = 90.7 ± 2.8 kcal mol^(□1). The C-H bond dissociation energies at the benzyl-α sites of the phenylmethanes are determined as 80.9 ± 2.3 kcal mol⁻¹ for benzyl nitrile and an upper limit of 84.2 kcal mol⁻¹ for benzyl chloride. These results are discussed in terms of substituent interactions in a simple MO framework and in relation to other similar molecules, including recently reported results for chloroacetonitrile. The 532 nm photoelectron spectrum of glyoxal provides the first direct spectroscopic determination of the adiabatic electron affinity, EA = 1.10(2) eV. This assignment is supported by a Franck-Condon simulation of the experimental spectrum that successfully reproduces the observed spectral features. The vertical detachment energy (VDE) of the glyoxal radical anion is determined as VDE = 1.30(4) eV. The EA of methylglyoxal is determined as ≤0.8 eV based on the signal-to-noise ratio of the 𝑋¹A′←𝑋²A″ transition, with a VDE = 1.28(4) eV. The EA of the a³A″ ← X²A″ and 𝐴¹A″ ← 𝑋²A″ transitions are determined as 3.28(3) eV and 3.614(5) eV respectively. The intrinsically short-lived ethylenedione molecule (OCCO) was observed and investigated using anion photoelectron spectroscopy. The adiabatic electron affinity of its ³Σg^(□) ground state is 1.936(8) eV. The vibrational progression with a 417(15) cm⁻¹ frequency observed within the triplet band corresponds to a trans-bending mode. Several dissociative singlet states are also observed, corresponding to two components of the ¹Δg state and the ¹Σg⁺ state. The experimental results are in agreement with the theory predictions and constitute the first spectroscopic observation and characterization of the elusive ethylenedione molecule. Two glyoxal derivatives related to the ethylenedione anion (OCCO⁻), ethynediolide (HOCCO⁻) and glyoxalide (OHCCO⁻), were studied. These anions provide access to the corresponding neutral reactive intermediates: the HOCCO and OHCCO radicals. In the HOCCO/OHCCO anion photoelectron spectrum, we identify several electronic states of this radical system and determine the adiabatic electron affinity of HOCCO as 1.763(6) eV. This result is compared to the corresponding 1.936(8) eV value for ethylenedione (OCCO). Initial attempts were made to detect and observe the dicyanoacetylene anion, NCCCCN⁻, by photoelectron imaging. While it is believed the experimental design path of H₂⁺ abstraction from fumaronitrile is sound, no spectral signature can be assigned to NCCCCN⁻. Calculations targeting the low-lying transitions from the anion indicate that the molecule should have a significantly positive electron affinity and at least the ground state should be accessible with the currently available laser sources. The cluster ion O₂(N₂O)⁻ of the same nominal mass as NCCCCN⁻ is identified as an interfering ion and ideas have been proposed for resolving this difficulty.

Aqueous anions play an important role in our world, and the ability to continuously measure them provides both environmental and health benefits. Chemically-sensitive field effect transistors (ChemFETs) are becoming increasingly popular in the field of aqueous measurement due to their relatively low-cost capability for real-time, continuous sensing. Receptor molecules or mixtures displaying affinity for a particular ion can also be utilized in a ChemFET gate membrane. Receptors can be incorporated into the gate oxide membrane and the entire ChemFET can utilized in an aqueous environment, thus utilizing hydrophobic receptors in an aqueous anion-sensing application. Demonstrating the ability to reuse the sensors validates an important characteristic for ChemFET-based research. Additionally, numerous other receptor molecules are evaluated against an array of common anions. Selectivity coefficients are compared to the Hofmeister Series. Additional membranes are evaluated for suitability for incorporation of receptors on the ChemFET gate oxide surface. This thesis includes previously unpublished co-authored material. / 2021-04-30

Répondre aux besoins croissants en termes de stockage électrochimique sans épuiser les ressources naturelles exige de promouvoir des technologies de batteries en rupture à la fois efficientes mais aussi à faible impact au plan environnemental. La conception de batteries organiques pourrait s'avérer être une partie de la solution. En effet, la richesse de la chimie organique offre une multitude de possibilités pour développer des matériaux d'électrode innovants à partir d’éléments abondants et peu coûteux. Près de 40 ans après la découverte des polymères conducteurs, des batteries Li-organiques offrent maintenant d’intéressantes performances en cyclage. Pourtant, la synthèse de matériaux organiques lithiés électroactifs à haut-potentiel ainsi que celle de matériaux organiques de type p électroactifs à bas potentiel se sont avérées assez complexes et par conséquent, très peu d'exemples de cellules « tout organique » existent. Au cours de ce travail de recherche, nous avons mis en lumière une approche chimique originale consistant à perturber la structure électronique de l’entité organique électroactive (modulation des effets inductifs) au moyen d’un cation spectateur faiblement électropositif ce qui conduit à une augmentation significative du potentiel redox des matériaux d'électrodes organiques lithiés déjà connus. Cette découverte nous a permis de développer une batterie Li-ion « tout organique » capable d’offrir une tension de sortie d’au moins 2,5 V sur plus de 300 cycles. Ensuite, nous avons cherché à concevoir des matériaux de type p capables de fonctionner à bas potentiel et ainsi élaboré des batteries Anion-ion « tout organique ». Enfin, une étude préliminaire d’une nouvelle famille de composés potentiellement bipolaires au plan redox (intégration de centres redox de type n et de type p) a également été réalisée. / Meeting the ever-growing demand for electrical storage devices, without depleting natural resources, requires both superior and “greener” battery technologies. Developing organic batteries could well provide part of the solution since the richness of organic chemistry affords us a multitude of avenues for uncovering innovative electrode materials based on abundant, low-cost chemical elements. Nearly 40 years after the discovery of conductive polymers, long cycling stability in Li-organic batteries has now been achieved. However, the synthesis of high-voltage lithiated organic cathode materials and the synthesis of low-voltage p type organic anode materials is still rather challenging, so very few examples of all-organic cells currently exist. Herein, we first present an innovative approach consisting in the substitution of spectator cations and leading to a significant increase of the redox potential of lithiated organic electrode materials thanks to an inductive effect. These results enable developing an all-organic Li-ion battery able to deliver an output voltage above 2.5 V for more than 300 cycles. We then design two p type organic electrode materials able of being charged at low potentials for developing all-organic Anion-ion batteries able to deliver an output voltage at least 1.5 V. Finally, we present a preliminary study of a new family of potentially bipolar compounds.