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Peroutka AA, Wang X, Servis MJ, Shafer JC. Influence of Aqueous Phase Acidity on Ln(III) Coordination by N, N, N', N'-Tetraoctyldiglycolamide. Inorg Chem 2024; 63:10466-10470. [PMID: 38768519 DOI: 10.1021/acs.inorgchem.4c01006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
This study highlights the importance of combining distribution ratio measurements with multiple spectroscopic techniques to provide a more comprehensive understanding of organic phase Ln coordination chemistry. Solvent extraction investigations with N,N,N',N'-tetraoctyldiglycolamide (TODGA) in n-heptane reveal the sensitivity of Ln complexation to the HNO3 concentration. Distribution ratio measurements in tandem with UV-Vis demonstrated that increasing the concentration of HNO3 above 0.5 M with a constant NO3- of 1 M increases the number of coordinating TODGA molecules, from a 1:2 to a 1:3 Ln:TODGA complex. At each concentration of HNO3 considered herein (from 0.01 to 1 M), Eu lifetime analysis demonstrated no evidence of H2O coordination. Results from Fourier transform infrared investigations suggest the presence of inner-sphere NO3- under low concentrations of HNO3 when the 1:2 Ln:TODGA complex is present. Increasing the HNO3 concentration above 0.5 M increases the propensity for outer-sphere interactions by removing the coordinated NO3- and saturating the Ln coordination sphere with three TODGA molecules, resulting in the well-established cationic, trischelate homoleptic [Ln(TODGA)3]3+ complex. This work demonstrates the importance in considering the NO3- source for solvent extraction systems. In particular, for systems with an affinity for outer-sphere interactions with molar concentrations of HNO3, changing the NO3- source can change the inner-sphere coordination of the Ln complex, which, in turn, affects the separation efficacy.
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Affiliation(s)
- Allison A Peroutka
- Department of Chemistry, Colorado School of Mines, 1500 Illinois Street, Golden, Colorado 80401, United States
| | - Xiaoyu Wang
- Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439, United States
| | - Michael J Servis
- Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439, United States
| | - Jenifer C Shafer
- Department of Chemistry, Colorado School of Mines, 1500 Illinois Street, Golden, Colorado 80401, United States
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2
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Clark JA, Robinson S, Espinoza EM, Bao D, Derr JB, Croft L, O'Mari O, Grover WH, Vullev VI. Poly(dimethylsiloxane) as a room-temperature solid solvent for photophysics and photochemistry. Phys Chem Chem Phys 2024; 26:8062-8076. [PMID: 38372740 DOI: 10.1039/d3cp05413f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Medium viscosity strongly affects the dynamics of solvated species and can drastically alter the deactivation pathways of their excited states. This study demonstrates the utility of poly(dimethylsiloxane) (PDMS) as a room-temperature solid-state medium for optical spectroscopy. As a thermoset elastic polymer, PDMS is transparent in the near ultraviolet, visible, and near infrared spectral regions. It is easy to mould into any shape, forming surfaces with a pronounced smoothness. While PDMS is broadly used for the fabrication of microfluidic devices, it swells in organic solvents, presenting severe limitations for the utility of such devices for applications employing non-aqueous fluids. Nevertheless, this swelling is reversible, which proves immensely beneficial for loading samples into the PDMS solid matrix. Transferring molecular-rotor dyes (used for staining prokaryotic cells and amyloid proteins) from non-viscous solvents into PDMS induces orders-of-magnitude enhancement of their fluorescence quantum yield and excited-state lifetimes, providing mechanistic insights about their deactivation pathways. These findings demonstrate the unexplored potential of PDMS as a solid solvent for optical applications.
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Affiliation(s)
- John A Clark
- Department of Bioengineering, University of California, Riverside, CA 92521, USA.
| | - Samantha Robinson
- Department of Bioengineering, University of California, Riverside, CA 92521, USA.
| | - Eli M Espinoza
- Department of Chemistry, University of California, Riverside, CA 92521, USA
| | - Duoduo Bao
- Department of Bioengineering, University of California, Riverside, CA 92521, USA.
| | - James B Derr
- Department of Biochemistry, University of California, Riverside, CA 92521, USA
| | - Luca Croft
- Department of Bioengineering, University of California, Riverside, CA 92521, USA.
| | - Omar O'Mari
- Department of Bioengineering, University of California, Riverside, CA 92521, USA.
| | - William H Grover
- Department of Bioengineering, University of California, Riverside, CA 92521, USA.
| | - Valentine I Vullev
- Department of Bioengineering, University of California, Riverside, CA 92521, USA.
- Department of Chemistry, University of California, Riverside, CA 92521, USA
- Department of Biochemistry, University of California, Riverside, CA 92521, USA
- Materials Science and Engineering Program, University of California, Riverside, CA 92521, USA
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3
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Derr JB, Tamayo J, Clark JA, Morales M, Mayther MF, Espinoza EM, Rybicka-Jasińska K, Vullev VI. Multifaceted aspects of charge transfer. Phys Chem Chem Phys 2020; 22:21583-21629. [PMID: 32785306 PMCID: PMC7544685 DOI: 10.1039/d0cp01556c] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Charge transfer and charge transport are by far among the most important processes for sustaining life on Earth and for making our modern ways of living possible. Involving multiple electron-transfer steps, photosynthesis and cellular respiration have been principally responsible for managing the energy flow in the biosphere of our planet since the Great Oxygen Event. It is impossible to imagine living organisms without charge transport mediated by ion channels, or electron and proton transfer mediated by redox enzymes. Concurrently, transfer and transport of electrons and holes drive the functionalities of electronic and photonic devices that are intricate for our lives. While fueling advances in engineering, charge-transfer science has established itself as an important independent field, originating from physical chemistry and chemical physics, focusing on paradigms from biology, and gaining momentum from solar-energy research. Here, we review the fundamental concepts of charge transfer, and outline its core role in a broad range of unrelated fields, such as medicine, environmental science, catalysis, electronics and photonics. The ubiquitous nature of dipoles, for example, sets demands on deepening the understanding of how localized electric fields affect charge transfer. Charge-transfer electrets, thus, prove important for advancing the field and for interfacing fundamental science with engineering. Synergy between the vastly different aspects of charge-transfer science sets the stage for the broad global impacts that the advances in this field have.
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Affiliation(s)
- James B Derr
- Department of Biochemistry, University of California, Riverside, CA 92521, USA.
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4
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Deng Q, Zhu Z, Shu X. Auto-Phase-Locked Time-Resolved Luminescence Detection: Principles, Applications, and Prospects. Front Chem 2020; 8:562. [PMID: 32695750 PMCID: PMC7339960 DOI: 10.3389/fchem.2020.00562] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 06/02/2020] [Indexed: 11/23/2022] Open
Abstract
Time-resolved luminescence measurement is a useful technique which can eliminate the background signals from scattering and short-lived autofluorescence. However, the relative instruments always require pulsed excitation sources and high-speed detectors. Moreover, the excitation and detecting shutter should be precisely synchronized by electronic phase matching circuitry, leading to expensiveness and high-complexity. To make time-resolved luminescence instruments simple and cheap, the automatic synchronization method was developed by using a mechanical chopper acted as both of the pulse generator and detection shutter. Therefore, the excitation and detection can be synchronized and locked automatically as the optical paths fixed. In this paper, we first introduced the time-resolved luminescence measurements and review the progress and current state of this field. Then, we discussed low-cost time-resolved techniques, especially chopper-based time-resolved luminescence detections. After that, we focused on auto-phase-locked method and some of its meaningful applications, such as time-gated luminescence imaging, spectrometer, and luminescence lifetime detection. Finally, we concluded with a brief outlook for auto-phase-locked time-resolved luminescence detection systems.
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Affiliation(s)
| | - Zece Zhu
- Wuhan National Laboratory for Optoelectronics & School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, China
| | - Xuewen Shu
- Wuhan National Laboratory for Optoelectronics & School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, China
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5
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Zhu Z. Smartphone-based apparatus for measuring upconversion luminescence lifetimes. Anal Chim Acta 2018; 1054:122-127. [PMID: 30712582 DOI: 10.1016/j.aca.2018.12.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 12/01/2018] [Accepted: 12/07/2018] [Indexed: 11/15/2022]
Abstract
Luminescence lifetime detection plays an important role in time-resolved detection and research. However, the traditional instruments always require expensive detectors such as time-correlated single photon counter or streak camera. Herein, a low-cost and miniaturized apparatus for measuring upconversion luminescence lifetimes was developed by using a smartphone equipped with a 980 nm CW laser and a motor. When the motor was driving the sample circling at a high linear velocity, the excited sample would emit a luminescence arc, which could be photographed by the phone camera. The rotating rate could be measured by a tuner APP and then used for transferring arc length to delay times. By analyzing the grayscale distribution of the luminescence arc, the luminescence decay curve was obtained, which was then used for exponential fit and calculating lifetimes. The images captured by different smartphones revealed similar lifetime values, suggesting a wide universality of this method. The whole system was not only remarkably cheaper but also more miniaturized than traditional instruments for measuring luminescence lifetimes, indicating the promising applications in point of care testing for time-resolved luminescence detection for bioanalysis and disease diagnosis.
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Affiliation(s)
- Zece Zhu
- Wuhan National Laboratory for Optoelectronics & School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, 430074, China.
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6
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Espinoza EM, Larsen-Clinton JM, Krzeszewski M, Darabedian N, Gryko DT, Vullev VI. Bioinspired approach toward molecular electrets: synthetic proteome for materials. PURE APPL CHEM 2017. [DOI: 10.1515/pac-2017-0309] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
AbstractMolecular-level control of charge transfer (CT) is essential for both, organic electronics and solar-energy conversion, as well as for a wide range of biological processes. This article provides an overview of the utility of local electric fields originating from molecular dipoles for directing CT processes. Systems with ordered dipoles, i.e. molecular electrets, are the centerpiece of the discussion. The conceptual evolution from biomimicry to biomimesis, and then to biological inspiration, paves the roads leading from testing the understanding of how natural living systems function to implementing these lessons into optimal paradigms for specific applications. This progression of the evolving structure-function relationships allows for the development of bioinspired electrets composed of non-native aromatic amino acids. A set of such non-native residues that are electron-rich can be viewed as a synthetic proteome for hole-transfer electrets. Detailed considerations of the electronic structure of an individual residue prove of key importance for designating the points for optimal injection of holes (i.e. extraction of electrons) in electret oligomers. This multifaceted bioinspired approach for the design of CT molecular systems provides unexplored paradigms for electronic and energy science and engineering.
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Affiliation(s)
- Eli M. Espinoza
- Department of Chemistry, University of California, Riverside, CA 92521, USA
| | | | - Maciej Krzeszewski
- Department of Bioengineering, University of California, Riverside, CA 92521, USA
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44-52, 01-224 Warsaw, Poland
| | - Narek Darabedian
- Department of Bioengineering, University of California, Riverside, CA 92521, USA
| | - Daniel T. Gryko
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44-52, 01-224 Warsaw, Poland
| | - Valentine I. Vullev
- Department of Chemistry, University of California, Riverside, CA 92521, USA
- Department of Bioengineering, University of California, Riverside, CA 92521, USA
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7
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Pominova DV, Ryabova AV, Grachev PV, Romanishkin ID, Kuznetsov SV, Rozhnova JA, Yasyrkina DS, Fedorov PP, Loschenov VB. Upconversion microparticles as time-resolved luminescent probes for multiphoton microscopy: desired signal extraction from the streaking effect. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:96002. [PMID: 27604561 DOI: 10.1117/1.jbo.21.9.096002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 08/10/2016] [Indexed: 06/06/2023]
Abstract
The great interest in upconversion nanoparticles exists due to their high efficiency under multiphoton excitation. However, when these particles are used in scanning microscopy, the upconversion luminescence causes a streaking effect due to the long lifetime. This article describes a method of upconversion microparticle luminescence lifetime determination with help of modified Lucy–Richardson deconvolution of laser scanning microscope (LSM) image obtained under near-IR excitation using nondescanned detectors. Determination of the upconversion luminescence intensity and the decay time of separate microparticles was done by intensity profile along the image fast scan axis approximation. We studied upconversion submicroparticles based on fluoride hosts doped with Yb3+-Er3+ and Yb3+-Tm3+ rare earth ion pairs, and the characteristic decay times were 0.1 to 1.5 ms. We also compared the results of LSM measurements with the photon counting method results; the spread of values was about 13% and was associated with the approximation error. Data obtained from live cells showed the possibility of distinguishing the position of upconversion submicroparticles inside and outside the cells by the difference of their lifetime. The proposed technique allows using the upconversion microparticles without shells as probes for the presence of OH? ions and CO2 molecules.
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Affiliation(s)
- Daria V Pominova
- A. M. Prokhorov General Physics Institute, Russian Academy of Sciences, Vavilov Street, 38, Moscow 119991, Russia
| | - Anastasia V Ryabova
- A. M. Prokhorov General Physics Institute, Russian Academy of Sciences, Vavilov Street, 38, Moscow 119991, RussiabNational Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Kashirskoe Highway, 31, Moscow, 115409, Russia
| | - Pavel V Grachev
- A. M. Prokhorov General Physics Institute, Russian Academy of Sciences, Vavilov Street, 38, Moscow 119991, Russia
| | - Igor D Romanishkin
- A. M. Prokhorov General Physics Institute, Russian Academy of Sciences, Vavilov Street, 38, Moscow 119991, Russia
| | - Sergei V Kuznetsov
- A. M. Prokhorov General Physics Institute, Russian Academy of Sciences, Vavilov Street, 38, Moscow 119991, Russia
| | - Julia A Rozhnova
- A. M. Prokhorov General Physics Institute, Russian Academy of Sciences, Vavilov Street, 38, Moscow 119991, Russia
| | - Daria S Yasyrkina
- A. M. Prokhorov General Physics Institute, Russian Academy of Sciences, Vavilov Street, 38, Moscow 119991, Russia
| | - Pavel P Fedorov
- A. M. Prokhorov General Physics Institute, Russian Academy of Sciences, Vavilov Street, 38, Moscow 119991, Russia
| | - Victor B Loschenov
- A. M. Prokhorov General Physics Institute, Russian Academy of Sciences, Vavilov Street, 38, Moscow 119991, RussiabNational Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Kashirskoe Highway, 31, Moscow, 115409, Russia
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8
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Espinoza EM, Xia B, Darabedian N, Larsen JM, Nuñez V, Bao D, Mac JT, Botero F, Wurch M, Zhou F, Vullev VI. Nitropyrene Photoprobes: Making Them, and What Are They Good for? European J Org Chem 2015. [DOI: 10.1002/ejoc.201501339] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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9
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Li QF, Yue D, Ge GW, Du X, Gong Y, Wang Z, Hao J. Water-soluble Tb(3+) and Eu(3+) complexes based on task-specific ionic liquid ligands and their application in luminescent poly(vinyl alcohol) films. Dalton Trans 2015; 44:16810-7. [PMID: 26337142 DOI: 10.1039/c5dt02555a] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Novel water-soluble lanthanide complexes (Ln(IMI-DPA)3) have been synthesized using the task-specific ionic liquid consisting of a dipicolinic acid motif as the sensitizer of lanthanide luminescence. In Ln(IMI-DPA)3, Ln(3+) ions are in 9-fold coordination through six carboxylate oxygen atoms and three nitrogen atoms in pyridine units, and the water molecule is excluded from the coordination sphere of the lanthanides. It is found that Ln(IMI-DPA)3 possess bright luminescence, long luminescence lifetime in aqueous solution, high thermal stability and good water solubility. Furthermore, these complexes can be incorporated into water-soluble poly(vinyl alcohol) (PVA) matrixes to obtain highly luminescent, transparent and flexible PVA composite films. The emission colors of the films can be tuned from red, orange, yellow, light green, green to white light by regulating the concentration of the various luminescent components.
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Affiliation(s)
- Qing-Feng Li
- The Key Laboratory of Rare Earth Functional Materials and Applications, Zhoukou Normal University, Zhoukou 466001, P. R. China.
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10
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Larsen JM, Espinoza EM, Hartman JD, Lin CK, Wurch M, Maheshwari P, Kaushal RK, Marsella MJ, Beran GJO, Vullev VI. Building blocks for bioinspired electrets: molecular-level approach to materials for energy and electronics. PURE APPL CHEM 2015. [DOI: 10.1515/pac-2015-0109] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
AbstractIn biology, an immense diversity of protein structural and functional motifs originates from only 20 common proteinogenic native amino acids arranged in various sequences. Is it possible to attain the same diversity in electronic materials based on organic macromolecules composed of non-native residues with different characteristics? This publication describes the design, preparation and characterization of non-native aromatic β-amino acid residues, i.e. derivatives of anthranilic acid, for polyamides that can efficiently mediate hole transfer. Chemical derivatization with three types of substituents at two positions of the aromatic ring allows for adjusting the energy levels of the frontier orbitals of the anthranilamide residues over a range of about one electronvolt. Most importantly, the anthranilamide residues possess permanent electric dipoles, adding to the electronic properties of the bioinspired conjugates they compose, making them molecular electrets.
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Affiliation(s)
- Jillian M. Larsen
- 1Department of Bioengineering, University of California, Riverside, CA, 92507, USA
| | - Eli M. Espinoza
- 2Department of Chemistry, University of California, Riverside, CA, 92507, USA
| | - Joshua D. Hartman
- 2Department of Chemistry, University of California, Riverside, CA, 92507, USA
| | - Chung-Kuang Lin
- 1Department of Bioengineering, University of California, Riverside, CA, 92507, USA
| | - Michelle Wurch
- 1Department of Bioengineering, University of California, Riverside, CA, 92507, USA
| | - Payal Maheshwari
- 1Department of Bioengineering, University of California, Riverside, CA, 92507, USA
| | - Raman K. Kaushal
- 1Department of Bioengineering, University of California, Riverside, CA, 92507, USA
| | - Michael J. Marsella
- 2Department of Chemistry, University of California, Riverside, CA, 92507, USA
| | - Gregory J. O. Beran
- 2Department of Chemistry, University of California, Riverside, CA, 92507, USA
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11
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Upadhyayula S, Nuñez V, Espinoza EM, Larsen JM, Bao D, Shi D, Mac JT, Anvari B, Vullev VI. Photoinduced dynamics of a cyanine dye: parallel pathways of non-radiative deactivation involving multiple excited-state twisted transients. Chem Sci 2015; 6:2237-2251. [PMID: 29449923 PMCID: PMC5701728 DOI: 10.1039/c4sc02881c] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Accepted: 02/09/2015] [Indexed: 12/11/2022] Open
Abstract
Cyanine dyes are broadly used for fluorescence imaging and other photonic applications. 3,3'-Diethylthiacyanine (THIA) is a cyanine dye composed of two identical aromatic heterocyclic moieties linked with a single methine, -CH[double bond, length as m-dash]. The torsional degrees of freedom around the methine bonds provide routes for non-radiative decay, responsible for the inherently low fluorescence quantum yields. Using transient absorption spectroscopy, we determined that upon photoexcitation, the excited state relaxes along two parallel pathways producing three excited-state transients that undergo internal conversion to the ground state. The media viscosity impedes the molecular modes of ring rotation and preferentially affects one of the pathways of non-radiative decay, exerting a dominant effect on the emission properties of THIA. Concurrently, the polarity affects the energy of the transients involved in the decay pathways and further modulates the kinetics of non-radiative deactivation.
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Affiliation(s)
- Srigokul Upadhyayula
- Department of Bioengineering , University of California , Riverside , CA 92521 , USA .
- Department of Biochemistry , University of California , Riverside , CA 92521 , USA
| | - Vicente Nuñez
- Department of Bioengineering , University of California , Riverside , CA 92521 , USA .
| | - Eli M Espinoza
- Department of Chemistry , University of California , Riverside , CA 92521 , USA
| | - Jillian M Larsen
- Department of Bioengineering , University of California , Riverside , CA 92521 , USA .
| | - Duoduo Bao
- Department of Bioengineering , University of California , Riverside , CA 92521 , USA .
| | - Dewen Shi
- Department of Bioengineering , University of California , Riverside , CA 92521 , USA .
| | - Jenny T Mac
- Department of Biochemistry , University of California , Riverside , CA 92521 , USA
| | - Bahman Anvari
- Department of Bioengineering , University of California , Riverside , CA 92521 , USA .
| | - Valentine I Vullev
- Department of Bioengineering , University of California , Riverside , CA 92521 , USA .
- Department of Biochemistry , University of California , Riverside , CA 92521 , USA
- Department of Chemistry , University of California , Riverside , CA 92521 , USA
- Materials Science and Engineering Program , University of California , Riverside , CA 92521 , USA
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12
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Bao D, Upadhyayula S, Larsen JM, Xia B, Georgieva B, Nuñez V, Espinoza EM, Hartman JD, Wurch M, Chang A, Lin CK, Larkin J, Vasquez K, Beran GJO, Vullev VI. Dipole-mediated rectification of intramolecular photoinduced charge separation and charge recombination. J Am Chem Soc 2014; 136:12966-73. [PMID: 25162490 DOI: 10.1021/ja505618n] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Controlling charge transfer at a molecular scale is critical for efficient light harvesting, energy conversion, and nanoelectronics. Dipole-polarization electrets, the electrostatic analogue of magnets, provide a means for "steering" electron transduction via the local electric fields generated by their permanent electric dipoles. Here, we describe the first demonstration of the utility of anthranilamides, moieties with ordered dipoles, for controlling intramolecular charge transfer. Donor-acceptor dyads, each containing a single anthranilamide moiety, distinctly rectify both the forward photoinduced electron transfer and the subsequent charge recombination. Changes in the observed charge-transfer kinetics as a function of media polarity were consistent with the anticipated effects of the anthranilamide molecular dipoles on the rectification. The regioselectivity of electron transfer and the molecular dynamics of the dyads further modulated the observed kinetics, particularly for charge recombination. These findings reveal the underlying complexity of dipole-induced effects on electron transfer and demonstrate unexplored paradigms for molecular rectifiers.
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Affiliation(s)
- Duoduo Bao
- Department of Bioengineering, ‡Department of Biochemistry, §Department of Chemistry, and ∥Materials Science and Engineering Program, University of California , Riverside, California 92521, United States
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13
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Wang T, Chen H, Liu K, Li Y, Xue P, Yu Y, Wang S, Zhang J, Kumacheva E, Yang B. Anisotropic Janus Si nanopillar arrays as a microfluidic one-way valve for gas-liquid separation. NANOSCALE 2014; 6:3846-53. [PMID: 24584666 DOI: 10.1039/c3nr05865d] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
In this paper, we demonstrate a facile strategy for the fabrication of a one-way valve for microfluidic (MF) systems. The micro-valve was fabricated by embedding arrays of Janus Si elliptical pillars (Si-EPAs) with anisotropic wettability into a MF channel fabricated in poly(dimethylsiloxane) (PDMS). Two sides of the Janus pillar are functionalized with molecules with distinct surface energies. The ability of the Janus pillar array to act as a valve was proved by investigating the flow behaviour of water in a T-shaped microchannel at different flow rates and pressures. In addition, the one-way valve was used to achieve gas-liquid separation. We believe that the Janus Si-EPAs modified by specific surface functionalization provide a new strategy to control the flow and motion of fluids in MF channels.
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Affiliation(s)
- Tieqiang Wang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, P. R. China.
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