Physical Sciences and Mathematics Commons^™

Competing Supramolecular Forces: Boron Coordination Vs Π-Π Stacking, Sidhaesh A. Agarwal, Gonzalo Campillo-Alvarado, Nicholas Lutz, Jesus Daniel Loya, Eric W. Reinheimer

Student Research Symposium

This study explores the impact of fluorination levels in azopyridine Lewis bases on their ability to direct the formation of B←N coordination adducts or cocrystals with phenylboronic ester. We hypothesize that the degree of fluorination can be used as a tool to control the outcome of supramolecular bonding competition, thus influencing complex self-assembly.

A series of azopyridines with varying degrees of fluorination were synthesized and reacted with phenylboronic ester. Their structures were analyzed using Hartree-Fock calculations, Hirshfeld surface analyses, and single crystal X-ray diffraction to assess the impact of fluorination on supramolecular interactions.

The study reveals that azopyridines with up …

Fluorogenic Probes For Thioredoxin Reductase Activity, Tendai J. Mafireyi, Jorge O. Escobedo, Robert Strongin

Chemistry Faculty Publications and Presentations

The thioredoxin system is vital in maintaining the cellular redox state and is implicated in various cancers and other diseases. It comprises of thioredoxin reductase, thioredoxin and NADPH. Various methods have been developed for the detection and quantification of the thioredoxin reductase enzyme. Most of these methods suffer the shortfall of poor specificity, hence there is need to develop more robust and specific techniques. Recently, there has been an increased interest in fluorescent probes that can target thioredoxin reductase. This review highlights the progress in the synthesis and application of the different fluorescent probes that have been employed for this …

Varied Length Stokes Shift Bodipy-Based Fluorophores For Multicolor Microscopy, Amy M. Bittel, Ashley M. Davis, Lei Wang, Michel A. Nederlof, Jorge O. Escobedo, Robert Strongin, Summer L. Gibbs

Chemistry Faculty Publications and Presentations

Multicolor microscopy tools necessary to localize and visualize the complexity of subcellular systems are limited by current fluorophore technology. While commercial fluorophores cover spectral space from the ultraviolet to the near infrared region and are optimized for conventional bandpass based fluorescence microscopy, they are not ideal for highly multiplexed fluorescence microscopy as they tend to have short Stokes shifts, restricting the number of fluorophores that can be detected in a single sample to four to five. Herein, we synthesized a library of 95 novel boron-dipyrromethene (BODIPY)- based fluorophores and screened their photophysical, optical and spectral properties for their utility in …

Preparation, Chemistry, And Characterization Of Hypervalent Organosulfur Fluorides, Paul R. Savoie

Legacy Theses & Dissertations (2009 - 2024)

Since the discovery of the pentafluorosulfanyl (SF5) group around the 1960s, progress in exploring the chemistry of aliphatic SF5-containing compounds stagnated because of a lack of efficient synthetic methods. More recent developments in the preparations of SF5-containing compounds afforded easier access to these compounds, and sparked great interest in exploring their chemistry. Chapter 1 discusses the development of efficient methods used to prepare SF5-containing aliphatic compounds.

Fluorinated Hypervalent Sulfur Compounds In Synthesis, Cortney Von Hahmann

Legacy Theses & Dissertations (2009 - 2024)

The polar and steric effects of pentafluorosulfanyl (SF5) substitution on selectivity and reactivity were investigated in the ketene imine [2+2] cycloaddition reaction. The kinetic resolution of racemic aldimines rely on the stereocontrol of cyclization by dipolar substituent effects. Functionalized SF5-bearing β-lactams are used in the preparation of conformationally constrained SF5-containing β-amino acids and peptides, in the study of novel antibacterial agents and in the design of new β-lactamase inhibitors.

Struktura Emisji Związków Fluoru Z Hutnictwa Żelaza Na Przykładzie Huty Katowice, Marian Mazur, Robert Oleniacz, Marek Bogacki

Robert Oleniacz

As recently as a dozen or so years ago ferrous metallurgy was known as one of the biggest source of fluorine compound emissions to the atmosphere. Nevertheless production technology and raw material changes occurring in this industry cause continuous decreasing of their participation in the total fluorine emission. On the ground of investigations that have been carried out in the Katowice Steelworks (Poland) in the last few years, participation of particular technological processing in the water-soluble fluorine compound emissions (which are regarded as toxic) were presented in the paper, as well as a position of fuel combustion process (that take …

Emisja Związków Fluoru Z Hutnictwa Żelaza, Marian Mazur, Marek Bogacki, Robert Oleniacz

Robert Oleniacz

The article presents the results of the last few years of comprehensive researches related to the emission of fluorine compounds from iron metallurgy in Poland. Determined of the levels of flue-gas concentrations and air emissions for fluorine in the form of gaseous and solid compounds, including water-soluble compounds (considered to be toxic). The study also made it possible to analyze of raw materials used in these processes taking into account fluorine content and its impact on the amount of fluorine compounds emitted to the air.

English title: Emissions of fluorine compounds with iron metallurgy.

Analiza Źródeł Emisji Związków Fluoru Z Procesów Hutnictwa Żelaza, Marian Mazur, Robert Oleniacz, Marek Bogacki

Robert Oleniacz

The paper presents the results of many years of complex research issues related to the emission of fluorine compounds of iron and steel processes. They allowed to examine these processes used in raw materials in terms of the fluorine content and their impact on the amount of emissions of fluorine compounds to the air. Were determined by measuring the levels of concentration in flue gases and stack emissions of fluorine in the form of gaseous and solid compounds, including water-soluble components (considered to be toxic).

English title: Analysis of emission sources of fluorine compounds from the processes of ferrous metallurgy.

Emisja Związków Fluoru Z Procesów Hutnictwa Żelaza, Marian Mazur, Marek Bogacki, Robert Oleniacz

Robert Oleniacz

The paper presents the results of a comprehensive study of issues related to emissions of fluorine compounds from ferrous metallurgy processes carried out over the last few years. As part of this study raw materials used in these processes were analyzed in terms of fluorine content and its impact on the amount of air emissions of fluorine compounds. Also determined by measuring the concentration levels and emissions of fluorine in the gaseous and solid phase, including water-soluble compounds (considered to be toxic).

English title: Emissions of fluorine compounds from the processes of ferrous metallurgy.

Synthesis And Characterization Of Novel Sf5 Containing Fluoroalkyl Iodides And Derivatives, Julia Anne Renn

Dissertations and Theses

Preparation of four SF5-containing fluoroalkyl iodides and derivatives thereof was accomplished beginning with a simplified synthesis of ICF2CF2I. Characterization of the products followed using a variety of spectroscopic and physical methods. The simplified method for preparing ICF2CF2I from iodine and tetrafluoroethylene (TFE) involved a reaction temperature of approximately 54°C and pressures of less than two atmospheres for the TFE. The synthesized ICF2CF2I was reacted with S2F1o and tetrafluoroethylene to give SF5CF2CF2I. The subsequent synthesis of the SFs containing fluoroalkyl iodides and derivatives were carried out using SFsCF2CF2I as the starting material in a Carius tube reaction vessel. The synthesized SFs …

Fluorinated Polymer Films - Synthesis And Characterization, Anja Ulrike Schnurer

Dissertations and Theses

Three polyfluoroalkyl epoxides, (I OCH2CHCH20CF2CF2S02F, II OCH2CHCH2(CF2)gF and III OCH2CHCH20(CF2)CF(CF3)S02F) were photopolymerized with a cycloaliphatic diepoxide (Cyracure UVR-6110) to form highly crosslinked glassy films. Depth-dependent surface analysis with XPS show that these films are highly enriched with sulfonyl fluoride groups in the outer molecular surface. Film compositions of 17 % wt and more of the fluorinated I and III show surface characteristics of a film composed of 100 % wt of the polymerized sulfonyl fluoride epoxide monomer (at depths for 50 A for each sample). Even films that are prepared with only 1 % wt or less (compound III) of …

Studies In Fluorine Chemistry: 13c Nmr Investigation Of Sf5/So2f Fluorinated Systems, Yoon S. Choi

Dissertations and Theses

The purpose of this thesis was two fold: (i) The synthesis and characterization of SF5 containing dienes. (ii) The characterization of hydro/fluorocarbon compounds containing SF5/S02F groups via their 13C NMR spectra. A new SF5CH2CHBrCH2CF=CF2 was prepared and characterized as a precursor to new dielectric polymers. This new adduct was made from the reaction of pentafluorothio bromide with l,l,2-trifluoro-1,4-pentadiene. A SF5-diene was prepared from the reaction of pentafluorothio chloride with acetylene. This reaction involves a radical addition mechanism. The SF5 group is bonded to the carbon atom carrying the most hydrogens. SF5 - dienes are capable of undergoing different reactions, such …

Chemistry Of Pentafluorothio (Sf5) Alkyl Derivatives, Rolf Walter Winter

Dissertations and Theses

Part I describes the preparation of a number of useful intermediates from the sultone F₅SCHCF₂OSO₂ (1). These intermediates include the following: the ketene F₅SC(SO₂)=C=O (21), the unique sultone F₄S=CCF₂OSO₂ (23), and various ionic intermediates of the form Y⁺ [F₅SC(SO₂F) COX]^-. These intermediates play an important role in providing new pathways for preparing fluorosulfonic acid precursors. Fluorosulfonic acids are excellent candidates to improve the efficiency of environmentally safe fuel cells. It was possible to obtain new derivatives of 1 by …

The Chemistry Of Sulfonyl Fluorides: Sf5 And/Or So2f Containing Compounds As Precursors To Sulfonic Acids, Robin Joyce Terjeson

Dissertations and Theses

Sulfonyl fluoride systems and their derivatives, RS0₂F, where R represents hydrocarbon/fluorocarbon moieties continue to be of considerable interest. The incorporation of the sulfonyl fluoride group (S0₂F) into molecular systems can lead to compounds that are useful as ion-exchange resins, surface active agents, fuel cell electrolytes, and strong sulfonic acids/salts.

Interest in preparing SF₅ containing sulfonyl fluorides led to the synthesis of the ᵝ-sultone, SF₅CHCF₂0S0₂, and its rearranged product. Hydrolysis of the sultone gave SF₅CH₂S0₂F which led to the sulfonic acid and salt, SF …

Fluorinated [Beta]-Sultones As Precursors To Fluorinated Sulfonic Acids, And New Fluorosulfonyl Containing Monomers/Polymers, Javid Mohtasham

Dissertations and Theses

Sulfur trioxide (SO₃) adds to fluoroolefins of the form RCF=CF₂, (where R = F, SF₅, CF₃, CF₃OCF₂, CF₂=CF(CF₂)₂, CF₃(CF₂)₃O, CF₃O(CF₂)₂OCF₂, or CH₂ClCHClCH₂), yielding the fluorinated [beta]-sultones, RCFCF₂OSO₂. In the case of CF₃(CF₂)₃OCF=CF₂, a reverse addition occurs, giving the sultone, CF₃(CF₂)₃CF₂2OCFCF₂SO₂O. The fluoro [beta]-sultones are capable of undergoing different reactions, such as rearrangement, hydrolysis, esterification, and polymerization. These reactions, will result in the formation of compounds containing the fluorosulfonyl grouping (SO₂F); it is this group that yields the corresponding sulfonic acid upon base/acid treatment.

The addition of sodium bisulfite to CF₃CF= CF₂ and CF₃(CF₂)₄CF=CF₂ in the presence of (C₆H₅CO)₂O₂ and Na₂B₄O₇·10H₂O …

Fluorinated Esters : Synthesis And Identification, Jilla Schaff

Dissertations and Theses

Reactions of different alcohols with 2-hydroxy - 1- trifluoromethyl -1,2,2-trifluoroethanesulfonic acid sultone were studied. Six new esters were prepared: C₆F₅OC(O)CF(CF₃)SO₂F, CH₃CH_2OC(O)CF(CF₃)SO₂F, CF₃CH₂OC(O)CF(CF₃)SO₂F, (CF₃)₂CHOC(O)CF(CF₃)SO₂F, CH2=CHCH20C(O)CF(CF3)SO₂F, (CH₂OC(O)CF(CF₃)SO₂F)₂. Analytical data, infrared, nmr and mass spectra are presented supporting the proposed structures for these new compounds.

The Chemistry Of Sf₅Br And Sf₅Cf=Cf₂ - Addition Reactions, Robin J. Debuhr

Dissertations and Theses

Addition reactions of pentafluorosulfur bromide (SF₅Br) with fluoroolefins were studied. Three new adducts were prepared, SF₅CHFCHC1Br, SF₅CH₂CH(CF₃)Br, SF₅CHFCFC1Br. SF₅Br and CFC1=CHC1 yielded a small amount of product but attempts to add SF₅Br to CF₂₌FCOF were unsuccessful.

The mechanism for these addition reactions seems to involve a free radical addition pathway. Steric factors seem to be important in determining whether SF₅Br will add to fluoroolefins.

The new compounds, SF₅CF(CF₃)COF and SF₅CF(CF₃ )CONH₂ have …

Carbon-Fluorine Chemistry, H. G. Bryce

Journal of the Minnesota Academy of Science

No abstract provided.