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Effect of aggregation on the simple ion transfer across oil|water interfaces. J Electroanal Chem (Lausanne) 2020. [DOI: 10.1016/j.jelechem.2020.114678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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2
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Zhou Z, Yan X, Lai YH, Zare RN. Fluorescence Polarization Anisotropy in Microdroplets. J Phys Chem Lett 2018; 9:2928-2932. [PMID: 29763551 DOI: 10.1021/acs.jpclett.8b01129] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Chemical reactions can be greatly accelerated in microdroplets, but the factors that lead to acceleration are still being elucidated. Using rhodamine 6G (R6G) as a model compound, we studied the density distribution and fluorescence polarization anisotropy of this dye in water-in-oil microdroplets. We found the density of R6G is higher on the surface of the microdroplets, and the ratio of the surface density to that of the center grows with increasing microdroplet radius or with decreasing R6G concentration. The measured fluorescence polarization anisotropy at the surface is almost the same for droplets of different sizes but becomes larger when the concentration is lowered. We also performed three-dimensional simulations by treating R6G+ and its associated anion as a dipole of fixed length and magnitude. The simulation results match quite well the experimental measurements, showing that the density distribution and fluorescence polarization anisotropy can be largely explained by a simple electrostatic model.
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Affiliation(s)
- Zhenpeng Zhou
- Department of Chemistry , Stanford University , Stanford , California 94305 , United States
| | - Xin Yan
- Department of Chemistry , Stanford University , Stanford , California 94305 , United States
| | - Yin-Hung Lai
- Department of Chemistry , Stanford University , Stanford , California 94305 , United States
| | - Richard N Zare
- Department of Chemistry , Stanford University , Stanford , California 94305 , United States
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3
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Martínez A, Colina A, Dryfe RA, Ruiz V. Spectroelectrochemistry at the liquid|liquid interface: Parallel beam UV–vis absorption. Electrochim Acta 2009. [DOI: 10.1016/j.electacta.2008.12.028] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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4
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Tsukahara S, Kamiya Y, Fujiwara T. In situ measurements of emission transition dipole moment of individual ordered microdomain of diprotonated tetraphenylporphine aggregate formed at dodecane/aqueous H2SO4 interface. Anal Bioanal Chem 2009; 395:1047-53. [DOI: 10.1007/s00216-009-2926-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2009] [Accepted: 06/18/2009] [Indexed: 11/30/2022]
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5
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Müller CB, Weiss K, Loman A, Enderlein J, Richtering W. Remote temperature measurements in femto-liter volumes using dual-focus-Fluorescence Correlation Spectroscopy. LAB ON A CHIP 2009; 9:1248-1253. [PMID: 19370244 DOI: 10.1039/b807910b] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Remote temperature measurements in microfluidic devices with micrometer spatial resolution are important for many applications in biology, biochemistry and chemistry. The most popular methods use the temperature-dependent fluorescence lifetime of Rhodamine B, or the temperature-dependent size of thermosensitive materials such as microgel particles. Here, we use the recently developed method of dual-focus fluorescence correlation spectroscopy (2fFCS) for measuring the absolute diffusion coefficient of small fluorescent molecules at nanomolar concentrations and show how these data can be used for remote temperature measurements on a micrometer scale. We perform comparative temperature measurements using all three methods and show that the accuracy of 2fFCS is comparable or even better than that achievable with Rhodamine B fluorescence lifetime measurements. The temperature dependent microgel swelling leads to an enhanced accuracy within a narrow temperature range around the volume phase transition temperature, but requires the availability of specific microgels, whereas 2fFCS is applicable under very general conditions.
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Affiliation(s)
- Claus B Müller
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 56056, Aachen, Germany
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6
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Müller CB, Richtering W. Sealed and temperature-controlled sample cell for inverted and confocal microscopes and fluorescence correlation spectroscopy. Colloid Polym Sci 2008. [DOI: 10.1007/s00396-008-1901-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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7
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Kamio E, Matsumoto M, Kondo K. Theoretical Development of Metal Extraction Mechanism into an Extractant-Impregnated Microcapsule. Ind Eng Chem Res 2006. [DOI: 10.1021/ie0608197] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Eiji Kamio
- Department of Chemical Engineering and Materials Science, Doshisha University, Kyotanabe, Kyoto 610-0321, Japan
| | - Michiaki Matsumoto
- Department of Chemical Engineering and Materials Science, Doshisha University, Kyotanabe, Kyoto 610-0321, Japan
| | - Kazuo Kondo
- Department of Chemical Engineering and Materials Science, Doshisha University, Kyotanabe, Kyoto 610-0321, Japan
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8
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Ishizaka S, Nishijima Y, Kitamura N. A thermodynamic study on the complexation between riboflavin and a diaminotriazine derivative mediated by triple hydrogen bonds at water/oil interfaces. Anal Bioanal Chem 2006; 386:749-58. [PMID: 16841208 DOI: 10.1007/s00216-006-0573-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2006] [Revised: 05/16/2006] [Accepted: 05/22/2006] [Indexed: 11/24/2022]
Abstract
The changes in Gibbs free energy (DeltaG (int)), enthalpy (DeltaH (int)) and entropy (TDeltaS (int)) upon complexation between riboflavin (RF) and N,N-dioctadecyl-[1,3,5]triazine-2,4,6-triamine (DTT), mediated by triple hydrogen bonds at water/carbon tetrachloride, trichloroethylene and chloroform interfaces, were determined via temperature-controlled interfacial tension measurements. It was shown that hydrogen bonding interactions between RF and DTT were best characterized by large and negative DeltaH (int) values, unlike those predicted from either the polarity in each phase or the arithmetic average of the polarities in the two phases. Furthermore, the DeltaH (int) values became more positive as the dielectric constant of the oil phase was increased. These results strongly indicate that DeltaH (int) is governed by the dielectric properties of the oil phase. Adsorption of RF, DTT and the RF-DTT complex at the water/oil interface gave rise to restrictions on the translational and rotational motions of these species, as demonstrated by the DeltaS (int) values observed, which is another characteristic of interfacial complexation. The thermodynamic parameters evaluated in the present study revealed the characteristic complexation behavior that occurs at a water/oil interface, as mediated by hydrogen bonding.
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Affiliation(s)
- Shoji Ishizaka
- Division of Chemistry, Graduate School of Science, Hokkaido University, Kita-ku, Sapporo, 060-0810, Japan
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9
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Nagatani H, Suzuki S, Fermín DJ, Girault HH, Nakatani K. Interfacial behavior of sulforhodamine 101 at the polarized water/1,2-dichloroethane interface studied by spectroelectrochemical techniques. Anal Bioanal Chem 2006; 386:633-8. [PMID: 16802124 DOI: 10.1007/s00216-006-0497-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2006] [Accepted: 04/19/2006] [Indexed: 10/24/2022]
Abstract
The transfer mechanism of an amphoteric rhodamine, sulforhodamine 101 (SR101), across the polarized water/1,2-dichloroethane (DCE) interface was investigated using cyclic voltammetry, differential voltfluorometry and potential-modulated fluorescence (PMF) spectroscopy. The voltammetric response for the ion transfer of SR101 monoanion from water to DCE was observed as the diffusion-controlled transfer process. An unusual voltammetric response was found at 0.15 V more negative than the formal transfer potential of SR101(-) (deltaW(O)phi degrees') in the cyclic voltammogram and voltfluorogram. The frequency dependence of the PMF responses confirmed the presence of the adsorption processes at negative potentials. In addition, a further transient adsorption step was uncovered at deltaW(O)phi degrees'. The interfacial mechanism of SR101 is discussed by comparing the results obtained from each technique.
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Affiliation(s)
- Hirohisa Nagatani
- Department of Applied Chemistry, Faculty of Engineering, Nagasaki University, Bunkyo, Nagasaki, 852-8521, Japan.
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10
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Tsukahara S. Recent analytical methodologies on equilibrium, kinetics, and dynamics at liquid/liquid interface. Anal Chim Acta 2006; 556:16-25. [PMID: 17723327 DOI: 10.1016/j.aca.2005.05.050] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2005] [Accepted: 05/19/2005] [Indexed: 12/01/2022]
Abstract
The form of liquid/liquid interface is flexible and it cannot be fixed at a spatial position. Also the interface is prevented from any physical contact by the organic phase and aqueous phase. In addition, analytical methods operated in vacuo cannot be applied. These restrictions depressed the development of liquid/liquid interfacial chemistry. However, the modification of liquid/liquid interfacial form and original analytical methods have been invented interdependently. The present review classifies the forms of liquid/liquid interface first, and it arrays the related analytical methods with brief explanations. It dominantly deals with recent reports of analytical methodologies, which were published in 2001-2004, on equilibrium, kinetics, and dynamics of substances at liquid/liquid interface, but it also includes historically important studies.
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Affiliation(s)
- Satoshi Tsukahara
- Department of Chemistry, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan.
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11
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Brodard P, Vauthey E. Application of Transient Evanescent Grating Techniques to the Study of Liquid/Liquid Interfaces. J Phys Chem B 2005; 109:4668-78. [PMID: 16851547 DOI: 10.1021/jp045133b] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Transient grating experiments performed with evanescent fields resulting from total internal reflection at an interface between a polar absorbing solution and an apolar transparent solvent are described. The time evolution of the diffracted intensity was monitored from picosecond to millisecond time scales. The diffracted signal originates essentially from two density phase gratings: one in the absorbing phase induced by thermal expansion and one in the transparent solvent due to electrostriction. A few nanoseconds after excitation, the latter grating is replaced by a thermal grating due to thermal diffusion from the absorbing phase. The speed of sound and the acoustic attenuation measured near the interface are found to be essentially the same as in the bulk solutions. However, after addition of a surfactant in the polar phase, the speed of sound near the interface differs substantially from that in the bulk with the same surfactant concentration. This effect is interpreted in terms of adsorption at the liquid/liquid interface. Other phenomena, which are not observed in bulk experiments, such as acoustic echoes and a fast oscillation of the signal intensity, are also described.
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Affiliation(s)
- Pierre Brodard
- Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, CH-1211 Geneva, Switzerland
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12
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Tsuboi Y, Okada K, Ishizaka S, Kitamura N. Molecular Probe for a Fluorous Medium: Long-Lived Phosphorescence of .ALPHA.-Diketones in Perfluoromethylcyclohexane at Room Temperature. ANAL SCI 2005; 21:303-8. [PMID: 15790117 DOI: 10.2116/analsci.21.303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We found that alpha-diketones (2,3-butanedione (BD) and 1-phenyl-1,2-propanedione (PPD)) were very suitable luminescence probes for studying the properties of a perfluorinated solvent (i.e., fluorous solvent; perfluoromethylcyclohexane (PFMC)), since these compounds were soluble in PFMC and showed long-lived phosphorescence even at room temperature. The phosphorescence lifetime (tau(p)) of BD in PFMC (650 micros) was much longer than that in cyclohexane (CH, 270 micros). The longer tau(p) value of BD in PFMC was ascribed to the variation of the intersystem crossing rate constant (k(isc)) from the excited triplet state (T1) to the ground state (S0) with the solvent. Some possible reasons for the change in k(isc) were discussed in terms of solute-solvent interactions. Furthermore, by utilizing phosphorescence quenching of BD by pyrene, we, determined a rate constant of the diffusion-controlled reaction in PFMC. Characteristic behaviors of mixing/separation processes between PFMC and a common organic solvent observed by Schlieren photographs were also reported.
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Affiliation(s)
- Yasuyuki Tsuboi
- Division of Chemistry, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan.
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13
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ISHIZAKA S, UEDA Y, NISHIJIMA Y, KITAMURA N. Time-Resolved Total-Internal-Reflection Fluorescence Study on Molecular Interactions at Liquid/Liquid Interfaces. BUNSEKI KAGAKU 2005. [DOI: 10.2116/bunsekikagaku.54.339] [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)
- Shoji ISHIZAKA
- Division of Chemistry, Graduate School of Science, Hokkaido University
| | - Yuichi UEDA
- Division of Chemistry, Graduate School of Science, Hokkaido University
| | | | - Noboru KITAMURA
- Division of Chemistry, Graduate School of Science, Hokkaido University
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14
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ISHIZAKA S, ARAKI T, NISHIJIMA Y, KITAMURA N. Excited-State Proton Transfer Dynamics of 6-Hydroxypyrene-1-Sulfonic Acid at a Water/1,2-Dichloroethane Interface. BUNSEKI KAGAKU 2005. [DOI: 10.2116/bunsekikagaku.54.473] [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)
- Shoji ISHIZAKA
- Division of Chemistry, Graduate School of Science, Hokkaido University
| | - Takeshi ARAKI
- Division of Chemistry, Graduate School of Science, Hokkaido University
| | | | - Noboru KITAMURA
- Division of Chemistry, Graduate School of Science, Hokkaido University
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15
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Wojciechowski K, Buffle J. The interaction of azacrown ether with fatty acid in nonpolar solvents and at the organic–aqueous interface. Biosens Bioelectron 2004; 20:1051-9. [PMID: 15556348 DOI: 10.1016/j.bios.2004.06.035] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2003] [Revised: 06/11/2004] [Accepted: 06/16/2004] [Indexed: 11/20/2022]
Abstract
In the paper, we show that lipophilic azacrown ether (22DD) in solvents of low to intermediate polarity forms the complexes with fatty acids, like lauric or palmitic acid. Due to the weak acid-base properties of the azacrown ether-fatty acid system, no proton transfer between the two molecules was observed, as shown by IR and 1H NMR studies. The Job plot exhibits double maximum, suggesting the coexistence of two 22DD-fatty acid complexes, of 1:1 and 1:2 stoichiometry, respectively. Their stability constants were calculated by taking into account the dimerization of fatty acid in toluene. The diffusion coefficients for the free molecules and their complexes were measured with diffusion-ordered spectroscopy (DOSY) NMR in order to prove the close spatial proximity of the molecules. Interfacial tension measurements at the water-toluene interface showed that due to the presence of two decyl chains, 22DD adsorbs at the interface much stronger than dodecanoic (lauric) acid does. The shape of the adsorption isotherm for the mixture of 22DD and lauric acid suggests that the two molecules also interact at the interface in a similar manner as in the bulk of low to intermediate polarity solvents. As a result of the affinity of the fatty acid to strongly surface-active azacrown ether, the interface might be enriched with fatty acid molecules, which without 22DD shows little adsorption at the liquid-liquid interface.
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Affiliation(s)
- Kamil Wojciechowski
- Analytical and Biophysical Environmental Chemistry (CABE), Department of Analytical, Inorganic and Applied Chemistry, Sciences II, 30 quai E. Ansermet, CH-1211 Geneva 4, Switzerland.
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16
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Yamaguchi A, Uchida T, Nochi K, Yamashita T, Teramae N. Adsorption behavior of lauric acid at heptane/water interface as studied by second harmonic generation spectroscopy and interfacial tensiometry. ANAL SCI 2004; 20:1523-7. [PMID: 15566143 DOI: 10.2116/analsci.20.1523] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Interfacial tensiometry and second harmonic generation (SHG) spectroscopy were applied to examine the adsorption behavior of lauric acid (LA) at a heptane/water interface. From interfacial tensiometry measurements, the adsorption kinetics of LA was revealed to be diffusion-controlled, and the adsorption constant of LA was estimated to be 9.6 x 10(4) M(-1). The adsorption isotherms obtained by SHG measurements were analyzed by taking account of both the molecular orientation of LA at the interface and a surface electric field generated by the adsorbed LA layer. It was confirmed that the carboxylic groups of adsorbed LA molecules were well ordered at the heptane/water interface and the orientation of the carboxylate group was invariant during the adsorption process.
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Affiliation(s)
- Akira Yamaguchi
- Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578, Japan
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17
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Ishizaka S, Ueda Y, Kitamura N. Time-Resolved Total Internal Reflection Fluorescence Study on Hybridization of Complementary Single-Stranded DNAs at a Water/Oil Interface. Anal Chem 2004; 76:5075-9. [PMID: 15373445 DOI: 10.1021/ac049612i] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hybridization of complementary single-stranded DNAs (ssDNA) at a water/CCl4 interface was studied on the basis of picosecond total internal reflection fluorescence spectroscopy. Complementary ssDNAs dissolved in water were shown to produce the relevant double-stranded DNA (dsDNA) at a water/CCl4 interface in the presence of octadecylamine (ODA) in the oil phase, while hybridization between ssDNAs did not proceed in the water phase, as demonstrated by the fluorescence dynamics of ethidium bromide as a probe for the DNA structure. The structures of dsDNA and the roles of ODA in hybridization of ssDNA at the interface were discussed.
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Affiliation(s)
- Shoji Ishizaka
- Division of Chemistry, Graduate School of Science, Hokkaido University, Kita-ku, Sapporo 060-0810, Japan
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18
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Thiourea–isothiouronium conjugate for strong and selective binding of very hydrophilic H2PO4− anion at the 1,2-dichloroethane–water interface. Tetrahedron Lett 2004. [DOI: 10.1016/j.tetlet.2004.04.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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19
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Pang XB, Huang CZ. A selective and sensitive assay of berberine using total internal reflected resonance light scattering technique with fluorescein at the water/1,2-dichloroethane interface. J Pharm Biomed Anal 2004; 35:185-91. [PMID: 15030893 DOI: 10.1016/j.jpba.2003.12.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2003] [Revised: 12/17/2003] [Accepted: 12/19/2003] [Indexed: 12/01/2022]
Abstract
An assay of berberine (BE) was developed with good selectivity and sensitivity based on the total internal reflected resonance light scattering (TIR-RLS) signals from water/1,2-dichloroethane (H(2)O/DCE) interface. Under optimal conditions, amphiphilic complex formed by BE and fluorescein (Flu) was adsorbed to H(2)O/DCE interface, resulting in good separation of BE from the coexisting foreign substances in aqueous phase and significant enrichment of BE at the interface. This enriched species at the interface was found corresponding to enhanced TIR-RLS signals located at 370.0 nm. Proportional relationships were established between the enhanced TIR-RLS intensity and the BE in the range of 3.2 x 10(-9) to 3.2 x 10(-6) mol l(-1) with the limit of detections (3sigma) being 1.3 ng ml(-1). Favorable sensitivity of TIR-RLS technique was demonstrated superior to that of high-performance liquid-chromatography (HPLC) method. The feasibility of the proposed technique was validated by the satisfactory performance of intra-assay and inter-assay BE in tablets.
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Affiliation(s)
- Xiao Bing Pang
- Laboratory of Supramolecular Chemistry and Biomedical Analysis, College of Chemistry and Chemical Engineering, Southwest China Normal University, Chongqing 400715, China
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20
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Tsuboi Y, Seto T, Ishizaka S, Kitamura N. Fluorescent Crystalloluminescence of N-Isopropylcarbazole. J Phys Chem B 2004. [DOI: 10.1021/jp036000d] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yasuyuki Tsuboi
- Division of Chemistry, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Toshiaki Seto
- Division of Chemistry, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Shoji Ishizaka
- Division of Chemistry, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Noboru Kitamura
- Division of Chemistry, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan
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21
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Kitamura N, Hosoda Y, Ueno K, Iwata S. An Application of Plastic Microchannel-Microheater Chips to a Thermal Synthetic Reaction. ANAL SCI 2004; 20:783-6. [PMID: 15171280 DOI: 10.2116/analsci.20.783] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Polystyrol microchannel-microheater chips were fabricated on the basis of imprinting and photolithography techniques. The solution (i.e., methanol) temperature in the vicinity of the microheater (width = 100 or 200 microm and length = 100 microm) integrated in the channel (width = 100 microm and depth = 20 microm) was evaluated on the basis of the temperature-dependent fluorescence lifetime of Rhodamine B as a function of a flow rate and the voltage applied to the heater. The study demonstrated that the fabricated chip acted certainly as a microheater. The chip was then applied to the thermal reaction between benzaldehyde and malononitrile in methanol. Under optimum conditions, benzilidenemalononitrile as the product of the reaction was obtained in a 96% yield with the reaction time of 84 s.
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Affiliation(s)
- Noboru Kitamura
- Division of Chemistry, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan
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22
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Nishizawa S, Kamaishi T, Yokobori T, Kato R, Cui YY, Shioya T, Teramae N. Facilitated Sulfate Transfer across the Nitrobenzene-Water Interface as Mediated by Hydrogen-Bonding Ionophores. ANAL SCI 2004; 20:1559-65. [PMID: 15566150 DOI: 10.2116/analsci.20.1559] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Facilitated SO4(2-) transfers by hydrogen bond-forming ionophores are investigated across the nitrobenzene (NB)-water interface by using polarography with a dropping electrolyte electrode. Bis-thiourea 1, alpha,alpha'-bis(N'-p-nitrophenylthioureylene)-m-xylene, is found to significantly facilitate the transfer of the highly hydrophilic SO4(2-) whereas its counterpart, N-(p-nitrophenyl)-N'-propylthiourea (ionophore 2), cannot. In contrast to the predominant formation of a 1:1 complex with SO4(2-) in the bulk NB phase, the SO4(2-) transfer assisted by 1 is indeed based on the formation of a 1:2 complex between SO4(2-) and ionophore, even under the condition of [SO4(2-)]aq >> [1]org. Such an exclusive formation of the 1:2 (SO4(2-) to ionophore) complex at the NB-water interface is not observed with structurally similar bis-thiourea 3, alpha,alpha'-bis(N'-phenylthioureylene)-m-xylene, where p-nitrophenyl moietes of bis-thiourea 1 are simply replaced by phenyl groups. The facilitated transfer of SO4(2-) with bis-thiourea 1 is further compared to that of HPO4(2-) and H2PO4- across the NB-water interface, which was previously shown to be assisted by 1 through the formation of the 1:1 and 2:1 (anion to ionophore) complexes, respectively. On the basis of these examinations, unique binding behaviors of hydrogen bond-forming ionophores at the NB-water interface are discussed, with a view towards development of ionophore-based anion-selective chemical sensors.
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Affiliation(s)
- Seiichi Nishizawa
- Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578, Japan
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23
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Ishizaka S, Kinoshita S, Nishijima Y, Kitamura N. Direct Observation of Molecular Recognition Mediated by Triple Hydrogen Bonds at a Water/Oil Interface: Time-Resolved Total Internal Reflection Fluorometry Study. Anal Chem 2003; 75:6035-42. [PMID: 14615978 DOI: 10.1021/ac034839j] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Molecular recognition mediated by hydrogen-bonding interactions at a water/CCl(4) interface was investigated directly by means of time-resolved total internal reflection (TIR) fluorescence spectroscopy. The TIR fluorescence decay profile of riboflavin (RF) in the absence of a guest in the CCl(4) phase was fitted satisfactorily by a single-exponential function. In the presence of N,N-dioctadecyl-[1,3,5]triazine-2,4,6-triamine (DTT) as a guest in the CCl(4) phase, on the other hand, the fluorescence decay profiles were best fitted by double-exponential functions with the relevant amplitude (A(i)) being varied with the concentration of DTT. Furthermore, the rotational reorientation time of RF at the interface determined by fluorescence dynamic anisotropy was 210 ps in the absence of DTT, while fast (160-220 ps) and slow (670-750 ps) rotational reorientation times were observed in the presence of DTT. This slow rotational reorientation time was shown to ascribe to that of the RF-DDT complex formed at the water/CCl(4) interface. These results indicate that molecular recognition mediated by complementary hydrogen bonding takes place effectively at the water/CCl(4) interface, which was observed directly by both fluorescence dynamics and fluorescence dynamic anisotropy measurements under the TIR conditions.
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Affiliation(s)
- Shoji Ishizaka
- Division of Chemistry, Graduate School of Science, Hokkaido University, Kita-ku, Sapporo 060-0810 Japan
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Watarai H, Tsukahara S, Nagatani H, Ohashi A. Interfacial Nanochemistry in Liquid–Liquid Extraction Systems. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2003. [DOI: 10.1246/bcsj.76.1471] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Yamashita T, Uchida T, Fukushima T, Teramae N. Solvation Dynamics of Fluorophores with an Anthroyloxy Group at the Heptane/Water Interface as Studied by Time-Resolved Total Internal Reflection Fluorescence Spectroscopy. J Phys Chem B 2003. [DOI: 10.1021/jp026163m] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Tomohisa Yamashita
- Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578, Japan
| | - Tatsuya Uchida
- Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578, Japan
| | - Takanori Fukushima
- Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578, Japan
| | - Norio Teramae
- Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578, Japan
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Schlossman ML. Liquid–liquid interfaces: studied by X-ray and neutron scattering. Curr Opin Colloid Interface Sci 2002. [DOI: 10.1016/s1359-0294(02)00053-5] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Shigemori K, Nishizawa S, Yokobori T, Shioya T, Teramae N. Selective binding of very hydrophilic H2PO4−anion by a hydrogen-bonding receptor adsorbed at the 1,2-dichloroethane–water interface. NEW J CHEM 2002. [DOI: 10.1039/b203881a] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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