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Amirghasemi F, Al-Shami A, Ushijima K, Mousavi MPS. Flexible Acetylcholine Neural Probe with a Hydrophobic Laser-Induced Graphene Electrode and a Fluorous-Phase Sensing Membrane. ACS MATERIALS LETTERS 2024; 6:4158-4167. [PMID: 39309214 PMCID: PMC11415234 DOI: 10.1021/acsmaterialslett.4c00825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/25/2024]
Abstract
This work develops the first laser-induced graphene (LIG)-based electrochemical sensor with a superhydrophobic fluorous membrane for a flexible acetylcholine (ACh) sensor. ACh regulates several physiological functions, including synaptic transmission and glandular secretion. The ACh sensing membrane is doped with a fluorophilic cation-exchanger that can selectively measure ACh based on the inherent selectivity of the fluorous phase for hydrophobic ions, such as ACh. The fluorous-phase sensor improves the selectivity for ACh over Na+ and K+ by 2 orders of magnitude (compared to traditional lipophilic membranes), thus lowering the detection limit in artificial cerebrospinal fluid (aCSF) from 331 to 0.38 μ M, thereby allowing measurement in physiologically relevant ranges of ACh. Engraving LIG under argon creates a hydrophobic surface with a 133.7° contact angle, which minimizes the formation of a water layer. The flexible solid-contact LIG fluorous sensor exhibited a slope of 59.3 mV/decade in aCSF and retained function after 20 bending cycles, thereby paving the way for studying ACh's role in memory and neurodegenerative diseases.
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Affiliation(s)
- Farbod Amirghasemi
- Alfred E. Mann Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, California 90089, United States
| | - Abdulrahman Al-Shami
- Alfred E. Mann Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, California 90089, United States
| | - Kara Ushijima
- Alfred E. Mann Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, California 90089, United States
| | - Maral P S Mousavi
- Alfred E. Mann Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, California 90089, United States
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2
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Kori S, Bhujbal Y, Vadagaonkar K, Kapdi AR, Kommyreddy SP, Gharpure SJ. Room temperature HFIP/Ag-promoted palladium-catalyzed C-H functionalization of benzothiazole with iodoarenes. Chem Commun (Camb) 2021; 58:847-850. [PMID: 34931644 DOI: 10.1039/d1cc06063e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A versatile synthetic protocol involving the room temperature direct arylation of benzothiazole with a wide variety of iodoarenes under Ag-promoted Pd-catalyzed conditions in HFIP as the reaction solvent has been presented. A sequential HFIP-promoted selective iodination of arenes followed by Pd-catalyzed direct arylation of benzothiazole has also been disclosed. The utility of the developed protocol has been demonstrated by the synthesis of anti-tumor agents, PMX-610 and CJM-126 (precursor).
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Affiliation(s)
- Santosh Kori
- Department of Chemistry, Institute of Chemical Technology, Nathalal Parekh Road, Matunga, Mumbai-400019, India. .,Institute of Chemical Technology-Indian Oil Odisha Campus, IIT Kharagpur Extension Centre, Mouza Samantpuri, Bhubaneswar-751013, Odisha, India
| | - Yuvraj Bhujbal
- Department of Chemistry, Institute of Chemical Technology, Nathalal Parekh Road, Matunga, Mumbai-400019, India.
| | - Kamlesh Vadagaonkar
- Department of Chemistry, Institute of Chemical Technology, Nathalal Parekh Road, Matunga, Mumbai-400019, India.
| | - Anant R Kapdi
- Department of Chemistry, Institute of Chemical Technology, Nathalal Parekh Road, Matunga, Mumbai-400019, India.
| | | | - Santosh J Gharpure
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India
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3
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Wang Y, Bai F, Wang A, Cui Z, Wang D, Shi S, Zhang T. Perfluorinated organics regulating Li 2O 2 formation and improving stability for Li-oxygen batteries. Chem Commun (Camb) 2021; 57:3030-3033. [PMID: 33624636 DOI: 10.1039/d0cc07774g] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Lithium-oxygen batteries have a high theoretical capacity, but they are still far from meeting the capacity required for practical applications. In this study, we systematically investigate the synergistic effect of perfluorotributylamine (PFTBA) as an additive in a TEGDME-based electrolyte to optimize the electrochemical performance of Li-O2 batteries. PFTBA promotes cyclic Li2O2 growth, and the discharge capacity is increased to 9548.7 mA h g-1. Moreover, the hydrophobicity of PFTBA can aid in the protection of the lithium anode against corrosion as it remains stable during cycling. The Li-O2 battery exhibited enhanced cycling stability (200 cycles) as a consequence. This study reveals that PFTBA increases the capacity and provides more possibilities for the application of perfluorinated chemicals in Li-O2 batteries.
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Affiliation(s)
- Yuling Wang
- School of Material Science & Engineering, Shanghai University, Shanghai 200072, P. R. China.
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4
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Biswas B, Singh PC. The role of fluorocarbon group in the hydrogen bond network, photophysical and solvation dynamics of fluorinated molecules. J Fluor Chem 2020. [DOI: 10.1016/j.jfluchem.2019.109414] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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5
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Chen XV, Mousavi MP, Bühlmann P. Fluorous-Phase Ion-Selective pH Electrodes: Electrode Body and Ionophore Optimization for Measurements in the Physiological pH Range. ACS OMEGA 2020; 5:13621-13629. [PMID: 32566827 PMCID: PMC7301372 DOI: 10.1021/acsomega.0c00582] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Accepted: 05/18/2020] [Indexed: 06/11/2023]
Abstract
Because of their low polarity and polarizability, fluorous sensing membranes are both hydrophobic and lipophobic and exhibit very high ion selectivities. Here, we report on a new fluorous-membrane ion-selective electrode (ISE) with a wide sensing range centered around physiologically relevant pH values. The fluorophilic tris[perfluoro(octyl)butyl]amine (N[(CH2)4Rf8]3) was synthesized and tested as a new H+ ionophore using a redesigned electrode body that provides excellent mechanical sealing and much improved measurement reliability. In a challenging 1 M KCl background, these fluorous-phase ISEs exhibit a sensing range from pH 2.2 to 11.2, which is one of the widest working ranges reported to date for ionophore-based H+ ISEs. High selectivities against common interfering ions such as K+, Na+, and Ca2+ were determined (selectivity coefficients: logK H, K pot = - 11.6; logK H, Na pot = - 12.4; logK H, Ca pot < - 10.2). The use of the N[(CH2)4Rf8]3 ionophore with its -(CH2)4- spacers separating the amino group from the strongly electron-withdrawing perfluorooctyl groups improved the potentiometric selectivity as compared to the less basic tris[perfluoro(octyl)propyl]amine ionophore. The use of N[(CH2)4Rf8]3 also made the ISE less prone to counter anion failure (i.e., Donnan failure) at low pH than the use of tris[perfluoro(octyl)pentyl]amine with its longer -(CH2)5- spacers, which more effectively shield the amino center from the perfluorooctyl groups. In addition, we exposed both conventional plasticized PVC-phase pH ISEs and fluorous-phase pH ISEs to 10% serum for 5 days. Results show that the PVC-phase ISEs lost selectivity while their fluorous-phase counterparts did not.
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6
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Yilmaz I, Chen LD, Chen XV, Anderson EL, da Costa RC, Gladysz JA, Bühlmann P. Potentiometric Selectivities of Ionophore-Doped Ion-Selective Membranes: Concurrent Presence of Primary Ion or Interfering Ion Complexes of Multiple Stoichiometries. Anal Chem 2019; 91:2409-2417. [PMID: 30609363 DOI: 10.1021/acs.analchem.8b05196] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The selectivities of ionophore-doped ion-selective electrode (ISE) membranes are controlled by the stability and stoichiometry of the complexes between the ionophore, L, and the target and interfering ions (I zi and J zj, respectively). Well-accepted models predict how these selectivities can be optimized by selection of ideal ionophore-to-ionic site ratios, considering complex stoichiometries and ion charges. These models were developed for systems in which the target and interfering ions each form complexes of only one stoichiometry. However, for a few ISEs, the concurrent presence of two primary ion complexes of different stoichiometries, such as IL zi and IL2 zi, was reported. Indeed, similar systems were probably often overlooked and are, in fact, more common than the exclusive formation of complexes of higher stoichiometry unless the ionophore is used in excess. Importantly, misinterpreted stoichiometries misguide the design of new ionophores and are likely to result in the formulation of ISE membranes with inferior selectivities. We show here that the presence of two or more complexes of different stoichiometries for a given ion may be inferred experimentally from careful interpretation of the potentiometric selectivities as a function of the ionophore-to-ionic site ratio or from calculations of complex concentrations using experimentally determined complex stabilities. Concurrent formation of JL zj and JL2 zj complexes of an interfering ion is shown here to shift the ionophore-to-ionic site ratio that provides the highest selectivities. Formation of IL n-1 zi and IL n zi complexes of a primary ion is less of a concern because an optimized membrane typically contains an excess of ionophore, but lower than expected selectivities may be observed if the stepwise complex formation constant, KILn, is not sufficiently large and the ionophore-to-ionic site ratio does not markedly exceed n.
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Affiliation(s)
- Ibrahim Yilmaz
- Department of Chemistry, Kamil Ozdag Science Faculty , Karamanoglu Mehmetbey University , 70100 Karaman , Turkey.,Department of Chemistry , University of Minnesota 207 Pleasant Street Southeast , Minneapolis , Minnesota 55455 , United States
| | - Li D Chen
- Department of Chemistry , University of Minnesota 207 Pleasant Street Southeast , Minneapolis , Minnesota 55455 , United States
| | - Xin V Chen
- Department of Chemistry , University of Minnesota 207 Pleasant Street Southeast , Minneapolis , Minnesota 55455 , United States
| | - Evan L Anderson
- Department of Chemistry , University of Minnesota 207 Pleasant Street Southeast , Minneapolis , Minnesota 55455 , United States
| | - Rosenildo Correa da Costa
- Department of Chemistry , Texas A&M University , P.O. Box 30012, College Station , Texas 77842 , United States.,School of Applied Sciences, Faculty of Computing, Engineering and Science , University of South Wales , Cemetery Road , Glyntaff , CF37 4DB , United Kingdom
| | - John A Gladysz
- Department of Chemistry , Texas A&M University , P.O. Box 30012, College Station , Texas 77842 , United States
| | - Philippe Bühlmann
- Department of Chemistry , University of Minnesota 207 Pleasant Street Southeast , Minneapolis , Minnesota 55455 , United States
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7
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Riddlestone IM, Kraft A, Schaefer J, Krossing I. Die Schöne (WCA) und das (kationische) Biest: Neues aus der Chemie von und mit schwach koordinierenden Anionen. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201710782] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Ian M. Riddlestone
- Institut für Anorganische und Analytische Chemie; Freiburger Materialforschungszentrum (FMF); Universität Freiburg; Albertstraße 21 79104 Freiburg Deutschland
| | - Anne Kraft
- Institut für Anorganische und Analytische Chemie; Freiburger Materialforschungszentrum (FMF); Universität Freiburg; Albertstraße 21 79104 Freiburg Deutschland
| | - Julia Schaefer
- Institut für Anorganische und Analytische Chemie; Freiburger Materialforschungszentrum (FMF); Universität Freiburg; Albertstraße 21 79104 Freiburg Deutschland
| | - Ingo Krossing
- Institut für Anorganische und Analytische Chemie; Freiburger Materialforschungszentrum (FMF); Universität Freiburg; Albertstraße 21 79104 Freiburg Deutschland
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8
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Riddlestone IM, Kraft A, Schaefer J, Krossing I. Taming the Cationic Beast: Novel Developments in the Synthesis and Application of Weakly Coordinating Anions. Angew Chem Int Ed Engl 2018; 57:13982-14024. [PMID: 29266644 DOI: 10.1002/anie.201710782] [Citation(s) in RCA: 251] [Impact Index Per Article: 41.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Indexed: 12/11/2022]
Abstract
This Review gives a comprehensive overview of the most topical weakly coordinating anions (WCAs) and contains information on WCA design, stability, and applications. As an update to the 2004 review, developments in common classes of WCA are included. Methods for the incorporation of WCAs into a given system are discussed and advice given on how to best choose a method for the introduction of a particular WCA. A series of starting materials for a large number of WCA precursors and references are tabulated as a useful resource when looking for procedures to prepare WCAs. Furthermore, a collection of scales that allow the performance of a WCA, or its underlying Lewis acid, to be judged is collated with some advice on how to use them. The examples chosen to illustrate WCA developments are taken from a broad selection of topics where WCAs play a role. In addition a section focusing on transition metal and catalysis applications as well as supporting electrolytes is also included.
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Affiliation(s)
- Ian M Riddlestone
- Institut für Anorganische und Analytische Chemie and Freiburger Materialforschungszentrum (FMF), Universität Freiburg, Albertstrasse 21, 79104, Freiburg, Germany
| | - Anne Kraft
- Institut für Anorganische und Analytische Chemie and Freiburger Materialforschungszentrum (FMF), Universität Freiburg, Albertstrasse 21, 79104, Freiburg, Germany
| | - Julia Schaefer
- Institut für Anorganische und Analytische Chemie and Freiburger Materialforschungszentrum (FMF), Universität Freiburg, Albertstrasse 21, 79104, Freiburg, Germany
| | - Ingo Krossing
- Institut für Anorganische und Analytische Chemie and Freiburger Materialforschungszentrum (FMF), Universität Freiburg, Albertstrasse 21, 79104, Freiburg, Germany
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9
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Scanga R, Chrastecka L, Mohammad R, Meadows A, Quan PL, Brouzes E. Click Chemistry Approaches to Expand the Repertoire of PEG-based Fluorinated Surfactants for Droplet Microfluidics. RSC Adv 2018; 8:12960-12974. [PMID: 31592185 PMCID: PMC6779154 DOI: 10.1039/c8ra01254g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
We report the novel and simplified synthesis of fluorinated surfactants for droplet microfluidics. The range of applications of droplet microfluidics has greatly expanded during the last decade thanks to its ability to manipulate and process tiny amount of sample and reagents at high throughput in independent reactors. A critical component of the technology is the formulation of the immiscible oil phase that contains surfactants to stabilize droplets. The success of droplet microfluidics relies mostly on a single fluorinated formulation that uses a PFPE–PEG triblock surfactant. The synthesis of this surfactant is laborious and requires skills in synthetic chemistry preventing the wider community to explore the synthesis of surfactants with alternate structures. We sought to provide a simplified synthesis for novel PFPE–PEG surfactants based on click chemistry approaches such as copper-catalyzed azide-alkyne cycloaddition (CuAAC) and UV-activated thiol–yne reactions. Our strategy is based on converting a moisture sensitive intermediate typically used in the synthesis of the triblock PFPE–PEG surfactant into a stable and click ready molecule. We successfully combined that fluorinated tail with differently functionalized PEG and glycerol ethoxylate molecules to generate surfactants with diverse structures via CuACC and thiol–yne reactions. We report the characterization, biocompatibility and ability to stabilize emulsions of those surfactants, as well as the unique advantages and challenges of the strategy. Click-synthesis of fluorinated surfactants for droplet microfluidics.![]()
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Affiliation(s)
- Randall Scanga
- Department of chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Lucie Chrastecka
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, USA
| | - Ridhwan Mohammad
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, USA
| | - Austin Meadows
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, USA
| | - Phenix-Lan Quan
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, USA
| | - Eric Brouzes
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York, USA.,Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, New York, USA
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10
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Honda M, Iwamoto T, Ohnogi T, Kunimoto KK, Segi M. Synthesis of fluorous pyrrolidinium and piperidinium ionic liquids. Tetrahedron Lett 2017. [DOI: 10.1016/j.tetlet.2017.07.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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11
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Lugert‐Thom EC, Gladysz JA, Rábai J, Bühlmann P. Cleaning of pH Selective Electrodes with Ionophore‐doped Fluorous Membranes in NaOH Solution at 90 °C. ELECTROANAL 2017. [DOI: 10.1002/elan.201700228] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Elizabeth C. Lugert‐Thom
- Department of Chemistry University of Minnesota 207 Pleasant St. SE Minneapolis, MN 55455 United States
| | - John A. Gladysz
- Department of Chemistry Texas A&M University P.O. Box 30012, College Station, TX 77842 United States
| | - József Rábai
- Institute of Chemistry Eötvös Loránd University Pázmány Péter sétány 1-A, H- 1117 Budapest Hungary
| | - Philippe Bühlmann
- Department of Chemistry University of Minnesota 207 Pleasant St. SE Minneapolis, MN 55455 United States
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12
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Black JE, Silva GMC, Klein C, Iacovella CR, Morgado P, Martins LFG, Filipe EJM, McCabe C. Perfluoropolyethers: Development of an All-Atom Force Field for Molecular Simulations and Validation with New Experimental Vapor Pressures and Liquid Densities. J Phys Chem B 2017; 121:6588-6600. [PMID: 28557461 DOI: 10.1021/acs.jpcb.7b00891] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A force field for perfluoropolyethers (PFPEs) based on the general optimized potentials for liquid simulations all-atom (OPLS-AA) force field has been derived in conjunction with experiments and ab initio quantum mechanical calculations. Vapor pressures and densities of two liquid PFPEs, perfluorodiglyme (CF3-O-(CF2-CF2-O)2-CF3) and perfluorotriglyme (CF3-O-(CF2-CF2-O)3-CF3), have been measured experimentally to validate the force field and increase our understanding of the physical properties of PFPEs. Force field parameters build upon those for related molecules (e.g., ethers and perfluoroalkanes) in the OPLS-AA force field, with new parameters introduced for interactions specific to PFPEs. Molecular dynamics simulations using the new force field demonstrate excellent agreement with ab initio calculations at the RHF/6-31G* level for gas-phase torsional energies (<0.5 kcal mol-1 error) and molecular structures for several PFPEs, and also accurately reproduce experimentally determined densities (<0.02 g cm-3 error) and enthalpies of vaporization derived from experimental vapor pressures (<0.3 kcal mol-1). Additional comparisons between experiment and simulation show that polyethers demonstrate a significant decrease in enthalpy of vaporization upon fluorination unlike related molecules (e.g., alkanes and alcohols). Simulation suggests this phenomenon is a result of reduced cohesion in liquid PFPEs due to a reduction in localized associations between backbone oxygen atoms and neighboring molecules.
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Affiliation(s)
- Jana E Black
- Department of Chemical and Biomolecular Engineering, Vanderbilt University , Nashville, Tennessee 37235, United States.,Multiscale Modeling and Simulation (MuMS), Vanderbilt University , Nashville, Tennessee 37235, United States
| | - Gonçalo M C Silva
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa , 1049-001 Lisboa, Portugal
| | - Christoph Klein
- Department of Chemical and Biomolecular Engineering, Vanderbilt University , Nashville, Tennessee 37235, United States.,Multiscale Modeling and Simulation (MuMS), Vanderbilt University , Nashville, Tennessee 37235, United States
| | - Christopher R Iacovella
- Department of Chemical and Biomolecular Engineering, Vanderbilt University , Nashville, Tennessee 37235, United States.,Multiscale Modeling and Simulation (MuMS), Vanderbilt University , Nashville, Tennessee 37235, United States
| | - Pedro Morgado
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa , 1049-001 Lisboa, Portugal
| | - Luís F G Martins
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa , 1049-001 Lisboa, Portugal.,Centro de Química de Évora, Universidade de Évora , Rua Romão Ramalho, 59, 7000-671 Évora, Portugal
| | - Eduardo J M Filipe
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa , 1049-001 Lisboa, Portugal
| | - Clare McCabe
- Department of Chemical and Biomolecular Engineering, Vanderbilt University , Nashville, Tennessee 37235, United States.,Multiscale Modeling and Simulation (MuMS), Vanderbilt University , Nashville, Tennessee 37235, United States.,Department of Chemistry, Vanderbilt University , Nashville, Tennessee 37235, United States
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13
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Anderson EL, Gingery NM, Boswell PG, Chen XV, Rábai J, Bühlmann P. Ion Aggregation and R 3N +-C(R)-H···NR 3 Hydrogen Bonding in a Fluorous Phase. J Phys Chem B 2016; 120:11239-11246. [PMID: 27723332 DOI: 10.1021/acs.jpcb.6b07299] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Potentiometric selectivities show that in fluorous ion-selective electrode membranes the tetrabutylammonium ion binds to fluorophilic proton ionophores. For the ionophore bis[3-(perfluorooctyl)propyl](2,2,2-trifluoroethyl)amine, this type of interaction is confirmed by the effect of the ionophore on the ionic conductivity of perfluoro(perhydrophenanthrene) solutions of a fluorophilic NBu4+ salt. In this system, ion pairs, triple ions, and higher ionic aggregates dominate over single ions, and the ionophore increases the conductivity by favoring the formation of ion aggregates with a net charge. These observations are consistent with the formation of R3N+-C(R)-H···NR3 type hydrogen bonds between the nitrogen atom of the ionophore and the hydrogen atoms in the α position to the positively charged quaternary ammonium center of NBu4+. Similar interactions were observed in a number of crystalline phases. To date, observations of C-H···N type hydrogen bonds in liquid phases have been very few, and solution-phase N+-C-H···N type hydrogen bonds have not been reported previously. Interestingly, no interactions between NBu4+ and the more basic ionophore tridodecylamine were observed in conventional plasticized poly(vinyl chloride) membranes doped with the ionophore tridodecylamine, emphasizing the uniquely low polarity of fluorous phases.
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Affiliation(s)
- Evan L Anderson
- Department of Chemistry, University of Minnesota , 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Nicole M Gingery
- Department of Chemistry, University of Minnesota , 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Paul G Boswell
- Department of Chemistry, University of Minnesota , 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Xin V Chen
- Department of Chemistry, University of Minnesota , 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - József Rábai
- Institute of Chemistry, Eötvös Loránd University , P.O. Box 32, H-1518 Budapest 112, Hungary
| | - Philippe Bühlmann
- Department of Chemistry, University of Minnesota , 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
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14
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Rubinson KA, Bühlmann P, Allison TC. One-dimensional ionic self-assembly in a fluorous solution: the structure of tetra-n-butylammonium tetrakis[3,5-bis(perfluorohexyl)phenyl]borate in perfluoromethylcyclohexane by small-angle neutron scattering (SANS). Phys Chem Chem Phys 2016; 18:9470-5. [PMID: 26980055 DOI: 10.1039/c6cp00393a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Fluorous liquids are the least polarizable condensed phases known, and their nonpolar members form solutions with conditions the closest to being in vacuo. A soluble salt consisting of a large fluorophilic anion, tetrakis[3,5-bis(perfluorohexyl)phenyl]borate, and its counterion, tetra-n-butylammonium, dissolved in perfluoromethylcyclohexane produces ionic solutions with extremely low conductivity. These solutions were subjected to small-angle neutron scattering (SANS) to ascertain the solute structure. At concentrations of 9% mass fraction, the fluorophilic electrolyte forms straight, long (>160 Å) self-assembled structures that are, in essence, long, homogeneous cylinders. Molecular models were made assuming a requirement for electroneutrality on the shortest length scale possible. This shows a structure formed from a stack of alternating anions and cations, and the structures fit the experimental scattering well. At the lower concentration of 1%, the stacks of ion pairs are shorter and eventually break up to form solitary ion pairs in the solution. These characteristics suggest such conditions provide an interesting new way to form long, self-assembling ionic nanostructures with single-molecule diameters in free solution onto which various moieties could be attached.
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Affiliation(s)
- Kenneth A Rubinson
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
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15
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Mousavi MPS, Gunsolus IL, Pérez De Jesús CE, Lancaster M, Hussein K, Haynes CL, Bühlmann P. Dynamic silver speciation as studied with fluorous-phase ion-selective electrodes: Effect of natural organic matter on the toxicity and speciation of silver. THE SCIENCE OF THE TOTAL ENVIRONMENT 2015; 537:453-461. [PMID: 26284896 PMCID: PMC4643687 DOI: 10.1016/j.scitotenv.2015.07.151] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 07/30/2015] [Accepted: 07/30/2015] [Indexed: 05/31/2023]
Abstract
The widespread application of silver in consumer products and the resulting contamination of natural environments with silver raise questions about the toxicity of Ag(+) in the ecosystem. Natural organic matter, NOM, which is abundant in water supplies, soil, and sediments, can form stable complexes with Ag(+), altering its bioavailability and toxicity. Herein, the extent and kinetics of Ag(+) binding to NOM, matrix effects on Ag(+) binding to NOM, and the effect of NOM on Ag(+) toxicity to Shewanella oneidensis MR-1 (assessed by the BacLight viability assay) were quantitatively studied with fluorous-phase Ag(+) ion-selective electrodes (ISEs). Our findings show fast kinetics of Ag(+) and NOM binding, weak Ag(+) binding for Suwannee River humic acid, fulvic acid, and aquatic NOM, and stronger Ag(+) binding for Pony Lake fulvic acid and Pahokee Peat humic acid. We quantified the effects of matrix components and pH on Ag(+) binding to NOM, showing that the extent of binding greatly depends on the environmental conditions. The effect of NOM on the toxicity of Ag(+) does not correlate with the extent of Ag(+) binding to NOM, and other forms of silver, such as Ag(+) reduced by NOM, are critical for understanding the effect of NOM on Ag(+) toxicity. This work also shows that fluorous-phase Ag(+) ISEs are effective tools for studying Ag(+) binding to NOM because they can be used in a time-resolved manner to monitor the activity of Ag(+) in situ with high selectivity and without the need for extensive sample preparation.
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Affiliation(s)
- Maral P S Mousavi
- Department of Chemistry, University of Minnesota, 207 Pleasant Street South East, Minneapolis, MN 55455, United States
| | - Ian L Gunsolus
- Department of Chemistry, University of Minnesota, 207 Pleasant Street South East, Minneapolis, MN 55455, United States
| | - Carlos E Pérez De Jesús
- Department of Chemistry, University of Minnesota, 207 Pleasant Street South East, Minneapolis, MN 55455, United States
| | - Mitchell Lancaster
- Department of Chemistry, University of Minnesota, 207 Pleasant Street South East, Minneapolis, MN 55455, United States
| | - Kadir Hussein
- Department of Chemistry, University of Minnesota, 207 Pleasant Street South East, Minneapolis, MN 55455, United States
| | - Christy L Haynes
- Department of Chemistry, University of Minnesota, 207 Pleasant Street South East, Minneapolis, MN 55455, United States.
| | - Philippe Bühlmann
- Department of Chemistry, University of Minnesota, 207 Pleasant Street South East, Minneapolis, MN 55455, United States.
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16
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Affiliation(s)
- Ian L. Gunsolus
- Department of Chemistry, University of Minnesota, 207 Pleasant
Street SE, Minneapolis, Minnesota 55455, United States
| | - Christy L. Haynes
- Department of Chemistry, University of Minnesota, 207 Pleasant
Street SE, Minneapolis, Minnesota 55455, United States
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Nishi N, Uruga T, Tanida H. Potential dependent structure of an ionic liquid at ionic liquid/water interface probed by x-ray reflectivity measurements. J Electroanal Chem (Lausanne) 2015. [DOI: 10.1016/j.jelechem.2015.11.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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18
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19
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Sharma N, Lakhman RK, Zhou Y, Kasi RM. Physical gels of [BMIM][BF4] byN- tert-butylacrylamide/ethylene oxide based triblock copolymer self-assembly: Synthesis, thermomechanical, and conducting properties. J Appl Polym Sci 2012. [DOI: 10.1002/app.38629] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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20
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Zhang T, Lai CZ, Fierke MA, Stein A, Bühlmann P. Advantages and Limitations of Reference Electrodes with an Ionic Liquid Junction and Three-Dimensionally Ordered Macroporous Carbon as Solid Contact. Anal Chem 2012; 84:7771-8. [DOI: 10.1021/ac3011507] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Tiantian Zhang
- College of Chemical
Engineering, Sichuan University, No. 24 South Section 1, Yihuan Road, Chengdu, Sichuan 610065, China
- Department of Chemistry, University of Minnesota, 207 Pleasant
Street SE, Minneapolis, Minnesota 55455, United States
| | - Chun-Ze Lai
- Department of Chemistry, University of Minnesota, 207 Pleasant
Street SE, Minneapolis, Minnesota 55455, United States
| | - Melissa A. Fierke
- Department of Chemistry, University of Minnesota, 207 Pleasant
Street SE, Minneapolis, Minnesota 55455, United States
| | - Andreas Stein
- Department of Chemistry, University of Minnesota, 207 Pleasant
Street SE, Minneapolis, Minnesota 55455, United States
| | - Philippe Bühlmann
- Department of Chemistry, University of Minnesota, 207 Pleasant
Street SE, Minneapolis, Minnesota 55455, United States
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22
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Miyake M, Chen LD, Pozzi G, Bühlmann P. Ion-selective electrodes with unusual response functions: simultaneous formation of ionophore-primary ion complexes with different stoichiometries. Anal Chem 2012; 84:1104-11. [PMID: 22128799 PMCID: PMC3264767 DOI: 10.1021/ac202761x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
It is well known that the selectivity of an ion-selective electrode (ISE) depends on the stoichiometry of the complexes between its ionophore and the target and interfering ions. It is all the more surprising that the possibility for the simultaneous occurrence of multiple target ion complexes with different complex stoichiometries was mostly ignored in the past. Here, we report on the simultaneous formation of 1:1 and 1:2 complexes of a fluorophilic crown ether in fluorous ISE membranes and how this results in what looks like super-Nernstian responses. These increased response slopes are not caused by mass transfer limitations and can be readily explained with a phase boundary model, a finding that is supported by experimentally determined complex formation constants and excellent fits of response curves. Not only Cs(+) but also the smaller ions Li(+), Na(+), K(+), and NH(4)(+) form 1:1 and 1:2 complexes with the fluorophilic crown ether, with cumulative formation constants of up to 10(15.0) and 10(21.0) for of the 1:1 and 1:2 complexes, respectively. Super-Nernstian responses of the type observed with these electrodes are probably not particularly rare but have lacked in the past an adequate discussion in the literature, remaining ignored or misinterpreted. Preliminary calculations also predict sub-Nernstian responses and potential dips of a similar origin. The proper understanding of such phenomena will facilitate the development of new ISEs based on ionophores that form complexes of higher stoichiometries.
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Affiliation(s)
- Masafumi Miyake
- Department of Chemistry, University of Minnesota, 207 Pleasant St. SE, Minneapolis MN 55455, USA
| | - Li D. Chen
- Department of Chemistry, University of Minnesota, 207 Pleasant St. SE, Minneapolis MN 55455, USA
| | - Gianluca Pozzi
- CNR-Istituto di Scienze Tecnologie Molecolari, via Golgi 19, 20133, Milano, Italy
| | - Philippe Bühlmann
- Department of Chemistry, University of Minnesota, 207 Pleasant St. SE, Minneapolis MN 55455, USA
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Chen LD, Mandal D, Pozzi G, Gladysz JA, Bühlmann P. Potentiometric sensors based on fluorous membranes doped with highly selective ionophores for carbonate. J Am Chem Soc 2011; 133:20869-77. [PMID: 22070518 PMCID: PMC3244523 DOI: 10.1021/ja207680e] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Manganese(III) complexes of three fluorophilic salen derivatives were used to prepare ion-selective electrodes (ISEs) with ionophore-doped fluorous sensing membranes. Because of their extremely low polarity and polarizability, fluorous media are not only chemically very inert but also solvate potentially interfering ions poorly, resulting in a much improved discrimination of such ions. Indeed, the new ISEs exhibited selectivities for CO(3)(2-) that exceed those of previously reported ISEs based on nonfluorous membranes by several orders of magnitude. In particular, the interference from chloride and salicylate was reduced by 2 and 6 orders of magnitude, respectively. To achieve this, the selectivities of these ISEs were fine-tuned by addition of noncoordinating hydrophobic ions (i.e., ionic sites) into the sensing membranes. Stability constants of the anion-ionophore complexes were determined from the dependence of the potentiometric selectivities on the charge sign of the ionic sites and the molar ratio of ionic sites and the ionophore. For this purpose, a previously introduced fluorophilic tetraphenylborate and a novel fluorophilic cation with a bis(triphenylphosphoranylidene)ammonium group, (R(f6)(CH(2))(3))(3)PN(+)P(R(f6)(CH(2))(3))(3), were utilized (where R(f6) is C(6)F(13)). The optimum CO(3)(2-) selectivities were found for sensing membranes composed of anionic sites and ionophore in a 1:4 molar ratio, which results in the formation of 2:1 complexes with CO(3)(2-) with stability constants up to 4.1 × 10(15). As predicted by established theory, the site-to-ionophore ratios that provide optimum potentiometric selectivity depend on the stoichiometries of the complexes of both the primary and the interfering ions. However, the ionophores used in this study give examples of charges and stoichiometries previously neither explicitly predicted by theory nor shown by experiment. The exceptional selectivity of fluorous membranes doped with these carbonate ionophores suggests their use not only for potentiometric sensing but also for other types of sensors, such as the selective separation of carbonate from other anions and the sequestration of carbon dioxide.
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Affiliation(s)
- Li D. Chen
- Department of Chemistry, University of Minnesota, 207 Pleasant St. SE, Minneapolis MN 55455, USA
| | - Debaprasad Mandal
- Department of Chemistry, Texas A&M University, PO Box 30012, College Station, Texas 77842
| | - Gianluca Pozzi
- CNR-Istituto di Scienze Tecnologie Molecolari, via Golgi 19, 20133, Milano, Italy
| | - John A. Gladysz
- Department of Chemistry, Texas A&M University, PO Box 30012, College Station, Texas 77842
| | - Philippe Bühlmann
- Department of Chemistry, University of Minnesota, 207 Pleasant St. SE, Minneapolis MN 55455, USA
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Lai CZ, Fierke MA, Corrêa da Costa R, Gladysz JA, Stein A, Bühlmann P. Highly selective detection of silver in the low ppt range with ion-selective electrodes based on ionophore-doped fluorous membranes. Anal Chem 2011; 82:7634-40. [PMID: 20799720 DOI: 10.1021/ac1013767] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Ionophore-doped sensing membranes exhibit greater selectivities and wider measuring ranges if their membrane matrixes are noncoordinating and solvate interfering ions poorly. This is particularly true for fluorous phases, which are the least polar and polarizable condensed phases known. In this work, fluorous membrane matrixes were used to prepare silver ion-selective electrodes (ISEs). Sensing membranes composed of perfluoroperhydrophenanthrene, sodium tetrakis[3,5-bis(perfluorohexyl) phenyl]borate, and one of four fluorophilic Ag(+)-selective ionophores with one or two thioether groups were investigated. All electrodes exhibited Nernstian responses to Ag(+) in a wide range of concentrations. Their selectivities for Ag(+) over interfering ions were found to depend on host preorganization and the length of the -(CH(2))(n)- spacers separating the coordinating thioether group from the strongly electron withdrawing perfluoroalkyl groups. ISEs based on the most selective of the four ionophores, that is, 1,3-bis(perfluorodecylethylthiomethyl)benzene, provided much higher selectivities for Ag(+) over many alkaline and heavy metal ions than most Ag(+) ISEs reported in the literature (e.g., log K(Ag,J)(pot) for K(+), -11.6; Pb(2+), -10.2; Cu(2+), -13.0; Cd(2+), -13.2). Moreover, the use of this ionophore with a linear perfluorooligoether as membrane matrix and solid contacts consisting of three-dimensionally ordered macroporous (3DOM) carbon resulted in a detection limit for Ag(+) of 4.1 ppt (3.8 × 10(-1)1 M).
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Affiliation(s)
- Chun-Ze Lai
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, USA
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25
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Corrêa da Costa R, Buffeteau T, Guerzo AD, McClenaghan ND, Vincent JM. Reversible hydrocarbon/perfluorocarbon phase-switching of [Ru(bipy)3]2+ driven by supramolecular heteromeric fluorous carboxylate–carboxylic acid H-bond interactions. Chem Commun (Camb) 2011; 47:8250-2. [DOI: 10.1039/c1cc12641e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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26
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Zhang H, Hussam A, Weber SG. Properties and transport behavior of perfluorotripentylamine (FC-70)-doped amorphous teflon AF 2400 films. J Am Chem Soc 2010; 132:17867-79. [PMID: 21105665 DOI: 10.1021/ja1075647] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Teflon AF 2400 films are known to imbibe solvents, making films in the presence of solvents less fluorous than they might otherwise be. Herein, we demonstrate that doping films with perfluorotripentylamine (Fluorinert FC-70) maintains the fluorous nature of Teflon AF 2400 and improves transport selectivity for fluorine-containing organic compounds. Density measurements on the FC-70-doped films reveal that free volume decreases dramatically as the dopant concentration increases (0-12 wt %) and then increases to approach that of pure FC-70. Remarkably, films from 0 to 12 wt % FC-70 have the same w/v concentration of Teflon AF 2400, indicating that FC-70 fills the free volume of Teflon AF 2400. This is consistent with the observed increased storage modulus and significant decrease (compared to undoped films) of solute diffusion coefficients in the same range of FC-70 concentrations. In contrast, FC-70 at concentrations greater than 12 wt % dilutes Teflon AF 2400, leading to a decrease of storage modulus and dramatic increase in solute diffusion coefficients. Sorption of chloroform decreases from 11.8 g of chloroform/100 g of film (pure Teflon film) to 3.8 g of chloroform/100 g of film (27 wt % FC-70-doped Teflon film), less than the solubility of chloroform in pure FC-70 (4.06 g of chloroform/100 g of FC-70). Solute partition coefficients from chloroform to FC-70-doped films generally decrease with increased dopant concentration. However, within a series of toluenes and nitrobenzenes, selectivity for F-containing solutes over analogous H-containing solutes increases as dopant concentration increases if the substitution is on the aromatic ring but not if it is on the methyl group (toluene). Transport (partitioning × diffusion) rates, as they involve both thermodynamic and kinetic factors, are not simply related to composition.
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Affiliation(s)
- Hong Zhang
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
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27
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O’Neal KL, Zhang H, Yang Y, Hong L, Lu D, Weber SG. Fluorous media for extraction and transport. J Chromatogr A 2010; 1217:2287-95. [DOI: 10.1016/j.chroma.2009.11.077] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Revised: 11/22/2009] [Accepted: 11/24/2009] [Indexed: 01/13/2023]
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Olson EJ, Boswell PG, Givot BL, Yao LJ, Bühlmann P. Electrochemistry in Media of Exceptionally Low Polarity: Voltammetry with a Fluorous Solvent. J Electroanal Chem (Lausanne) 2010; 639:154-160. [PMID: 20212920 PMCID: PMC2832752 DOI: 10.1016/j.jelechem.2009.12.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
This work demonstrates the first cyclic voltammetry in a perfluorocarbon solvent without use of a cosolvent. The novel electrolyte tetrabutylammonium tetrakis[3,5-bis(perfluorohexyl)phenyl]borate (NBu(4)BArF(104); 80 mM) allows for voltammetry of ferrocene in perfluoro(methylcyclohexane) by lowering the specific resistance to Ω268 k cm at 20.8 °C. Despite significant solution resistance, the resulting voltammograms can be fitted quantitatively without difficulty. The thus determined standard electron transfer rate constant, k°, for the oxidation of ferrocene in perfluoro(methylcyclohexane) is somewhat smaller than for many solvents commonly used in electrochemistry, but can be explained readily as the result of the viscosity and size of the solvent using Marcus theory. Dielectric dispersion spectroscopy verifies that addition of NBu(4)BArF(104) does not significantly raise the overall polarity of the solution over that of neat perfluoro(methylcyclohexane).
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Affiliation(s)
- Eric J Olson
- Department of Chemistry, University of Minnesota, 207 Pleasant St. SE, Minneapolis, MN 55455 (USA)
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29
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Mandal D, Gladysz JA. Syntheses of fluorous quaternary ammonium salts and their application as phase transfer catalysts for halide substitution reactions in extremely nonpolar fluorous solvents. Tetrahedron 2010. [DOI: 10.1016/j.tet.2009.11.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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30
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Jana S, Parthiban A, Chai CLL. Transparent, flexible and highly conductive ion gels from ionic liquid compatible cyclic carbonate network. Chem Commun (Camb) 2010; 46:1488-90. [DOI: 10.1039/b921517d] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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31
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Chen LD, Mandal D, Gladysz JA, Bühlmann P. Chemical stability and application of a fluorophilic tetraalkylphosphonium salt in fluorous membrane anion-selective electrodes. NEW J CHEM 2010. [DOI: 10.1039/b9nj00696f] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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32
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De Luca G, Liscio A, Melucci M, Schnitzler T, Pisula W, Clark CG, Scolaro LM, Palermo V, Müllen K, Samorì P. Phase separation and affinity between a fluorinated perylene diimide dye and an alkyl-substituted hexa-peri-hexabenzocoronene. ACTA ACUST UNITED AC 2010. [DOI: 10.1039/b915484a] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Abstract
The coordinative properties of perfluoro-15-crown-5 with monocations were investigated using (19)F NMR spectroscopy and ion-selective electrodes with perfluoro-15-crown-5 as the matrix of their sensor membranes and the fluorophilic tetrakis[3,5-bis(perfluorohexyl)phenyl]borate as ion exchanger site. The results show that perfluoro-15-crown-5 interacts weakly but significantly with Na(+) and K(+). Assuming 1:1 stoichiometry, the formal complexation constants were determined to be 5.5 and 1.7 M(-1), respectively. This weak binding is consistent with the strong electron withdrawing nature of the many fluorine atoms in the perfluorocrown ether. While perfluorinated crown ethers have been known to form host-guest complexes with the anions O(2) (-) and F(-) in the gas phase, this is the first study that quantitatively confirms cation binding to a perfluorocrown ether.
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Affiliation(s)
- Chun-Ze Lai
- University of Minnesota, Department of Chemistry, 207 Pleasant St. SE, Minneapolis, Minnesota 55455
| | - Molly E. Reardon
- University of Minnesota, Department of Chemistry, 207 Pleasant St. SE, Minneapolis, Minnesota 55455
| | - Paul G. Boswell
- University of Minnesota, Department of Chemistry, 207 Pleasant St. SE, Minneapolis, Minnesota 55455
| | - Philippe Bühlmann
- University of Minnesota, Department of Chemistry, 207 Pleasant St. SE, Minneapolis, Minnesota 55455
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Gels from a semifluorinated n-alkane in fluorinated solvents as a probe for intermolecular interactions. J Colloid Interface Sci 2009; 339:259-65. [DOI: 10.1016/j.jcis.2009.07.037] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2009] [Revised: 07/16/2009] [Accepted: 07/16/2009] [Indexed: 01/06/2023]
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36
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Yang Y, Vaidyanathan N, Weber SG. Porous alumina-based fluorous liquid membranes: Dependence of transport on fluorous solvent. J Fluor Chem 2009. [DOI: 10.1016/j.jfluchem.2009.08.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Lai CZ, Koseoglu SS, Lugert EC, Boswell PG, Rábai J, Lodge TP, Bühlmann P. Fluorous polymeric membranes for ionophore-based ion-selective potentiometry: how inert is Teflon AF? J Am Chem Soc 2009; 131:1598-1606. [PMID: 19133768 PMCID: PMC3227678 DOI: 10.1021/ja808047x] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Fluorous media are the least polar and polarizable condensed phases known. Their use as membrane materials considerably increases the selectivity and robustness of ion-selective electrodes (ISEs). In this research, a fluorous amorphous perfluoropolymer was used for the first time as a matrix for an ISE membrane. Electrodes for pH measurements with membranes composed of poly[4,5-difluoro-2,2-bis(trifluoromethyl)-1,3-dioxole]-co-poly(tetrafluoroethylene) (87% dioxole monomer content; known as Teflon AF2400) as polymer matrix, a linear perfluorooligoether as plasticizer, sodium tetrakis[3,5-bis(perfluorohexyl)phenyl]borate providing for ionic sites, and bis[(perfluorooctyl)propyl]-2,2,2-trifluoroethylamine as H+ ionophore were investigated. All electrodes had excellent potentiometric selectivities, showed Nernstian responses to H+ over a wide pH range, exhibited enhanced mechanical stability, and maintained their selectivity over at least 4 weeks. For membranes of low ionophore concentration, the polymer affected the sensor selectivity noticeably at polymer concentrations exceeding 15%. Also, the membrane resistance increased quite strongly at high polymer concentrations, which cannot be explained by the Mackie-Meares obstruction model. The selectivities and resistances depend on the polymer concentration because of a functional group associated with Teflon AF2400, with a concentration of one functional group per 854 monomer units of the polymer. In the fluorous environment of these membranes, this functional group binds to Na+, K+, Ca2+, and the unprotonated ionophore with binding constants of 10(3.5), 10(1.8), 10(6.8), and 10(4.4) M(-1), respectively. Potentiometric and spectroscopic evidence indicates that these functional groups are COOH groups formed by the hydrolysis of carboxylic acid fluoride (COF) groups originally present in Teflon AF2400. The use of higher ionophore concentrations removes the undesirable effect of these COOH groups almost completely. Alternatively, the C(=O)F groups can be eliminated chemically, or they can be used to readily introduce new functionalities.
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Bajaj VS, van der Wel PC, Griffin RG. Observation of a low-temperature, dynamically driven structural transition in a polypeptide by solid-state NMR spectroscopy. J Am Chem Soc 2009; 131:118-28. [PMID: 19067520 PMCID: PMC2651395 DOI: 10.1021/ja8045926] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
At reduced temperatures, proteins and other biomolecules are generally found to exhibit dynamic as well as structural transitions. This includes a so-called protein glass transition that is universally observed in systems cooled between 200 and 230 K, and which is generally attributed to interactions between hydrating solvent molecules and protein side chains. However, there is also experimental and theoretical evidence for a low-temperature transition in the intrinsic dynamics of the protein itself, absent any solvent. Here, we use low-temperature solid-state NMR to examine site-specific fluctuations in atomic structure and dynamics in the absence of solvents. In particular, we employ magic angle spinning NMR to examine a structural phase transition associated with dynamic processes in a solvent-free polypeptide, N-f-MLF-OH, lattice at temperatures as low as 90 K. This transition is characterized by the appearance of an extra set of lines in 1D (15)N spectra as well as additional cross peaks in 2D (13)C-(13)C and (13)C-(15)N spectra. Interestingly, the gradual, temperature-dependent appearance of the new spectral component is not accompanied by the line broadening typical of dynamic transitions. A direct comparison between the spectra of N-f-MLF-OH and the analog N-f-MLF-OMe, which does not display this transition, indicates a correlation of the structural transition to the temperature dependent motion of the aromatic phenylalanine side chain. Several quantitative solid state NMR experiments were employed to provide site-specific measurements of structural and motional features of the observed transition.
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Affiliation(s)
| | | | - Robert G. Griffin
- Francis Bitter Magnet Laboratory and Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
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Boswell PG, Anfang AC, Bühlmann P. Preparation of a Highly Fluorophilic Phosphonium Salt and its Use in a Fluorous Anion-Exchanger Membrane with High Selectivity for Perfluorinated Acids. J Fluor Chem 2008; 129:961-967. [PMID: 22072222 DOI: 10.1016/j.jfluchem.2008.05.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Fluorous solvents are the most nonpolar, nonpolarizable phases known, whereas ions are inherently polar. This makes it difficult to create salts that are soluble in a fluorous solvent. Here we present the synthesis and characterization of a new fluorophilic phosphonium salt, tris{3,5-bis[(perfluorooctyl)propyl]phenyl}methylphosphonium methyl sulfate. The salt has a solubility of at least 14 mM in perfluoro(perhydrophenanthrene), perfluoro(methylcyclohexane), and perfluorohexanes. It also shows immediate potential for use as a phase-transfer catalyst in fluorous biphasic catalysis, but in this work it is used as an anion exchanger site in the first potentiometric fluorous-membrane anion-selective electrode. The membrane sensor exhibited the exceptional selectivity of 3.9 × 10(10) to 1 for perfluorooctanesulfonate over chloride, and of 2.5 × 10(7) to 1 for perfluorooctanoate over chloride. With improvements to the sensor's detection limit and lifetime, it has the potential to be an attractive alternative to the expensive, time-consuming methods currently employed for measurement of perfluorinated acids.
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Affiliation(s)
- Paul G Boswell
- University of Minnesota, Department of Chemistry 207 Pleasant St. SE, Minneapolis, Minnesota 55455
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42
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Lugert EC, Lodge TP, Bühlmann P. Plasticization of amorphous perfluoropolymers. ACTA ACUST UNITED AC 2008. [DOI: 10.1002/polb.21385] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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43
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Kysilka O, Rybáčková M, Skalický M, Kvíčalová M, Cvačka J, Kvíčala J. HFPO Trimer-Based Alkyl Triflate, a Novel Building Block for Fluorous Chemistry. Preparation, Reactions and 19F gCOSY Analysis. ACTA ACUST UNITED AC 2008. [DOI: 10.1135/cccc20081799] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Triflate 4, CF3(CF2)2O-CF(CF3)CF2O-CF(CF3)CH2-OTf (RFOCH2OTf), of the HFPO trimer-based alcohol 3 (RFOCH2OH) is a novel highly fluorinated building block for fluorous chemistry. In analogy to similar polyfluorinated triflates with methylene spacer, its reactivity is limited to strong and soft nucleophiles. Whereas reactions with cyanide anion, phenolate anion, enolate of diethyl malonate or lithium salt of benzaldehyde bis(phenylsulfanyl)acetal were unsuccessful, the corresponding imidazole 5, iodide 6 or azide 7 were prepared in good yields. Reaction of imidazole 5 with (perfluorohexyl)methyl triflate (9) afforded highly fluorinated non-crystalline imidazolium salt 8, TfO-RFOCH2-(C3H3N2)+-CH2C6F13-n, which could be employed as fluorous ionic liquid or intermediate for fluorous carbenes. Complete assignment of complex 19F NMR spectra of all compounds employed was accomplished using 19F gCOSY NMR method.
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44
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He Y, Lodge TP. A thermoreversible ion gel by triblock copolymer self-assembly in an ionic liquid. Chem Commun (Camb) 2007:2732-4. [PMID: 17594036 DOI: 10.1039/b704490a] [Citation(s) in RCA: 166] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new thermoreversible ion gel with high ionic conductivity was developed through the self-assembly of a triblock copolymer, by choosing appropriate associating end-blocks for the ionic liquid.
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Affiliation(s)
- Yiyong He
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
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A spectroscopic study on medium polarity in fluorous alcohol. J Fluor Chem 2007. [DOI: 10.1016/j.jfluchem.2006.11.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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NISHI N, YAMAMOTO M, KAKIUCHI T. Optical Second Harmonic Generation Study of the Structure of the Interface between Water and an Ionic Liquid Based on N-Alkylisoquinolinium Ions. BUNSEKI KAGAKU 2007. [DOI: 10.2116/bunsekikagaku.56.491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Naoya NISHI
- Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University
| | - Masahiro YAMAMOTO
- Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University
| | - Takashi KAKIUCHI
- Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University
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Rábai J, Bálint AM, Szíjjártó C, Szabó D. Mixture Synthesis of Fluorous Ketals: Mitsunobu Reaction of Homologous 3-Perfluoroalkyl-propanols with Hexafluoroacetone Sesquihydrate and Collective Determination of Fluorophilicity Values. ACTA ACUST UNITED AC 2006. [DOI: 10.1002/qsar.200640046] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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