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Jang T, Lee S, Pang Y. Anomalous proton transfer of a photoacid HPTS in nonaqueous reverse micelles. Phys Chem Chem Phys 2024; 26:11283-11294. [PMID: 38456549 DOI: 10.1039/d3cp05710k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2024]
Abstract
The proton transfer reaction is one of the fundamental chemical reactions where the reaction dynamics strongly depend on solvent properties such as acidity or basicity. A photoacid 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS) shows a sharp decrease of pKa (7.7 → 0.5) upon photoexcitation, and the excited-state proton transfer (ESPT) occurs with ultrafast time constants of 2.5 and 89 ps in bulk aqueous solution. However, the two-step proton transfers via the contact ion pair formation and the proton diffusion are strongly limited inside the nanopools of reverse micelles (RMs). The confinement in small RMs strongly impeded the proton transfer reactions. In this work, we report the ESPT of HPTS confined in methanol-in-oil RMs by steady-state and time-resolved electronic spectroscopy. Interestingly, HPTS shows substantial deprotonation in the excited state only in small RMs, while the ESPT of HPTS does not occur in bulk methanol solution due to the low basicity of aliphatic alcohols. The kinetic analysis of time-resolved fluorescence and transient absorption measurements will compare the proton transfer dynamics of HPTS in the water-in-oil and methanol-in-oil RMs. The ESPT of photoacids, especially in the nonaqueous RMs, can be crucial in understanding many important chemical reactions involving proton transfer in the confined environments of cells and membranes.
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Affiliation(s)
- Taehyung Jang
- Department of Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea.
| | - Sebok Lee
- Department of Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea.
| | - Yoonsoo Pang
- Department of Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea.
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2
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Ghosh G, Roy DS, Ghosh R, Mukherjee D, Biswas S, Roy L, Chattopadhyay A, Das R, Pal SK. Excited-State Dynamics of a Photoacid: A Potential Probe for Recognizing Transition from Lamellar to Nonlamellar Inverted Structures of Liposome based Nanocarriers. Chemphyschem 2024; 25:e202300635. [PMID: 37936318 DOI: 10.1002/cphc.202300635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 11/04/2023] [Accepted: 11/07/2023] [Indexed: 11/09/2023]
Abstract
Liposomes of a cationic lipid dioctadecyldimethylammonium bromide (DODAB) are efficient nanocarriers of nucleic acids. Incorporation of a neutral lipid monoolein (MO) in excess (xMO >0.5) changes the lamellar organization of DODAB liposomes into non-lamellar inverted structures of DODAB/MO liposomes facilitating nucleic acid delivery to cells. Photoexcitation of 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS), a photoacid, initiates an excited state proton transfer (ESPT) reaction in its protonated form (ROH*) generating the deprotonated anionic form (RO- *). The fluorescence intensity ratio (IROH* /IRO-* ) of these two forms is governed by the ESPT dynamics, and increases with increasing MO content (xMO ) in the cationic liposomes of DODAB. Transition from lamellar organization of DODAB liposomes into non-lamellar inverted structures of DODAB/MO liposomes, due to incorporation of MO (xMO ~0.7), is manifested by a significant increase of ESPT time (τPT ) and the time constant of wobbling motion (τW ) of HPTS. Thus, the lamellar organizations of DODAB or DODAB-rich (xMO 0.2) liposomes and the non-lamellar organizations of MO-rich (xMO ~0.7) liposomes are recognized by significantly different excited state dynamics of the photoacid.
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Affiliation(s)
- Gourab Ghosh
- Dept. of Chemistry, West Bengal State University, Barasat, Kolkata, 700126, India
| | - Debanjana Singha Roy
- Dept. of Chemistry, West Bengal State University, Barasat, Kolkata, 700126, India
- Department of Chemical, Biological & Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata, India
| | - Ria Ghosh
- Technical Research Centre, S. N. Bose National Centre for Basic Sciences, Kolkata, India
| | - Dipanjan Mukherjee
- Department of Chemical, Biological & Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata, India
| | - Suman Biswas
- Dept. of Chemistry, West Bengal State University, Barasat, Kolkata, 700126, India
| | - Lopamudra Roy
- Department of Applied Optics and Photonics, University of Calcutta, 92, Acharya Prafulla Chandra Rd, Kolkata, 700009, India
| | - Arpita Chattopadhyay
- Department of Basic science and humanities, Techno International New Town, Rajarhat, Kolkata, 700156
| | - Ranjan Das
- Dept. of Chemistry, West Bengal State University, Barasat, Kolkata, 700126, India
| | - Samir Kumar Pal
- Department of Chemical, Biological & Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata, India
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3
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Pal T, Sahu K. Photophysical characterization of a sub-micellar triblock copolymer-cationic surfactant aggregate for nanostructure synthesis. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY 2021. [DOI: 10.1016/j.jpap.2021.100066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Oliveira H, Correia P, Pereira AR, Araújo P, Mateus N, de Freitas V, Oliveira J, Fernandes I. Exploring the Applications of the Photoprotective Properties of Anthocyanins in Biological Systems. Int J Mol Sci 2020; 21:E7464. [PMID: 33050431 PMCID: PMC7589295 DOI: 10.3390/ijms21207464] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 10/02/2020] [Accepted: 10/07/2020] [Indexed: 12/13/2022] Open
Abstract
Due to their physical and chemical characteristics, anthocyanins are amongst the most versatile groups of natural compounds. Such unique signature makes these compounds a focus in several different areas of research. Anthocyanins have well been reported as bioactive compounds in a myriad of health disorders such as cardiovascular diseases, cancer, and obesity, among others, due to their anti-inflammatory, antioxidant, anti-diabetic, anti-bacterial, and anti-proliferative capacities. Such a vast number of action mechanisms may be also due to the number of structurally different anthocyanins plus their related derivatives. In this review, we highlight the recent advances on the potential use of anthocyanins in biological systems with particular focus on their photoprotective properties. Topics such as skin aging and eye degenerative diseases, highly influenced by light, and the action of anthocyanins against such damages will be discussed. Photodynamic Therapy and the potential role of anthocyanins as novel photosensitizers will be also a central theme of this review.
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Affiliation(s)
| | | | | | | | | | | | - Joana Oliveira
- LAQV, REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal; (H.O.); (P.C.); (A.R.P.); (P.A.); (N.M.); (V.d.F.)
| | - Iva Fernandes
- LAQV, REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal; (H.O.); (P.C.); (A.R.P.); (P.A.); (N.M.); (V.d.F.)
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5
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Chakraborty S, Nandi S, Bhattacharyya K, Mukherjee S. Time Evolution of Local pH Around a Photo-Acid in Water and a Polymer Hydrogel: Time Resolved Fluorescence Spectroscopy of Pyranine. Chemphyschem 2019; 20:3221-3227. [PMID: 31596029 DOI: 10.1002/cphc.201900845] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 09/19/2019] [Indexed: 12/31/2022]
Abstract
In this work, we propose a new analysis of the time resolved emission spectra of a photo-acid, HA, pyranine (8-hydroxypyrene-1,3,6-trisulphonic acid, HPTS) based on time resolved area normalized emission spectra (TRANES). Presence of an isoemissive point in TRANES confirms the presence of two emissive species (HA and A- ) inside the system in bulk water and inside a co-polymer hydrogel [F127, (PEO)100 -(PPO)70 -(PEO)100 ]. We show that following electronic excitation, the local pH around HPTS, is much lower than the bulk pH presumably because of ejection of proton from the photo-acid in the excited state. With increase in time, the local pH increases and reaches the bulk value. We further, demonstrate that the excited state pKa of HPTS may be estimated from the emission intensities of HA and A- at long time. The time constant for time evolution of pH is ∼630 ps in water, ∼1300 ps in F127 gel and ∼4700 ps in CTAB micelle. The location and local viscosity sensed by the probe is ascertained using fluorescence correlation spectroscopy (FCS) and fluorescence anisotropy decay. The different values of the local viscosity reported by these two methods are reconciled.
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Affiliation(s)
- Subhajit Chakraborty
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhopal, 462 066, Madhya Pradesh, India
| | - Somen Nandi
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhopal, 462 066, Madhya Pradesh, India
| | - Kankan Bhattacharyya
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhopal, 462 066, Madhya Pradesh, India
| | - Saptarshi Mukherjee
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhopal, 462 066, Madhya Pradesh, India
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6
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Pal T, Sahu K. Anomalous Variation of Excited-State Proton Transfer Dynamics inside a Triblock Copolymer–Cationic Surfactant Mixed Micelle. J Phys Chem B 2019; 123:8559-8568. [DOI: 10.1021/acs.jpcb.9b06575] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Tapas Pal
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - Kalyanasis Sahu
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
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7
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Monteserín M, Burrows HD, Valente AJM, Pais AACC, Di Paolo RE, Maçanita AL, Tapia MJ. Fluorescence Enhancement of a Cationic Fluorene-Phenylene Conjugated Polyelectrolyte Induced by Nonionic n-Alkyl Polyoxyethylene Surfactants. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:13350-13363. [PMID: 29112441 DOI: 10.1021/acs.langmuir.7b02818] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The modulation of conjugated polyelectrolyte fluorescence response by nonionic surfactants is dependent on the structures of the surfactant and polymer, polymer average molecular weight, and polyelectrolyte-surfactant interactions. In this paper, we study the effect of nonionic n-alkyl polyoxyethylene surfactants (CiEj) with different alkyl chain lengths (CiE5 with i = 6, 8, 10, and 12) and number of oxyethylene groups (C12Ej with j = 5, 7, and 9) on the photophysics and ionic conductivity of poly{[9,9-bis(6'-N,N,N-trimethylammonium)-hexyl]-2,7-fluorene-alt-1,4-phenylene}bromide (HTMA-PFP) in dimethyl sulfoxide-water 4% (v/v). Molecular dynamics simulations show that HTMA-PFP chains tend to approach as the simulation evolves. However, the minimum distance between the polymer centers of mass increases upon addition of the surfactant and grows with both the surfactant alkyl chain length and the number of oxyethylene groups, although there are no specific polymer-surfactant interactions. A significant increase in the polymer emission intensity has been observed at surfactant concentrations around their critical micelle concentrations (cmcs), which is attributed to polymer aggregate disruption. However, an increase in the solution conductivity for concentrations above the C12E5 cmc has only been observed for the HTMA-PFP/C12E5 system. The enhancement of fluorescence emission intensity and conductivity upon surfactant addition increases with polymer average molecular weights and seems to be controlled by the polymer-surfactant proximity, which is maximum for C10E5 and C12E5.
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Affiliation(s)
- María Monteserín
- Departamento de Química, Universidad de Burgos , Plaza Misael Bañuelos, Burgos 09001, Spain
| | - Hugh D Burrows
- Centro de Química de Coimbra (CQC), Department of Chemistry, University of Coimbra , 3004-535 Coimbra, Portugal
| | - Artur J M Valente
- Centro de Química de Coimbra (CQC), Department of Chemistry, University of Coimbra , 3004-535 Coimbra, Portugal
| | - A A C C Pais
- Centro de Química de Coimbra (CQC), Department of Chemistry, University of Coimbra , 3004-535 Coimbra, Portugal
| | - Roberto E Di Paolo
- Departamento de Engenharia Química e Biologica, Instituto Superior Técnico (IST) , Avenida Rovisco Pais, P1049-001 Lisboa, Portugal
| | - Antonio L Maçanita
- Departamento de Engenharia Química e Biologica, Instituto Superior Técnico (IST) , Avenida Rovisco Pais, P1049-001 Lisboa, Portugal
| | - María J Tapia
- Departamento de Química, Universidad de Burgos , Plaza Misael Bañuelos, Burgos 09001, Spain
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8
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Roy B, Hazra P. Dynamics of different steps of the photopyrolytic cycle of an eminent anticancer drug topotecan inside biocompatible lyotropic liquid crystalline systems. RSC Adv 2017. [DOI: 10.1039/c6ra25200a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Dynamics of different steps of photopyrolytic processes of an eminent anticancer drug topotecan have been investigated inside different lyotropic liquid crystalline systems.
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Affiliation(s)
- Bibhisan Roy
- Department of Chemistry
- Indian Institute of Science Education and Research (IISER)
- Pune
- India
| | - Partha Hazra
- Department of Chemistry
- Indian Institute of Science Education and Research (IISER)
- Pune
- India
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9
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Phukon A, Ray S, Sahu K. How Does Interfacial Hydration Alter during Rod to Sphere Transition in DDAB/Water/Cyclohexane Reverse Micelles? Insights from Excited State Proton Transfer and Fluorescence Anisotropy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:6656-6665. [PMID: 27292367 DOI: 10.1021/acs.langmuir.6b01254] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
How does microscopic organization of an organized assembly alter during macroscopic structural transition? The question may be important to ascertain driving forces responsible for such transitions. Didodecyldimethylammonium bromide (DDAB)/water/cyclohexane reverse micelle is an attractive assembly that undergoes structural transition from rod to spherical shape when the amount of water loading, w0 ([water]/[surfactant]), exceeds a particular value (w0 ∼ 8). Here, we intend to investigate the effect of the morphological change upon interfacial hydration using steady-state and time-resolved fluorescence measurements. The anionic fluorophore 8-hydroxypyrene-1,3,6-trisulfonate (HPTS or pyranine) is expected to be trapped within the positively charged RM interface. The fluorophore can undergo excited-state proton transfer (ESPT) in the presence of water and, thus, is able to provide insight on the level of hydration within the interface. The ESPT process is markedly inhibited within the interface at low w0 and gradually favored with increase of w0. The time-resolved fluorescence decays could be best analyzed by assuming distribution of HPTS over two distinct interfacial regions- partly hydrated and mostly dehydrated. The relative population of the two regions varies distinctly at low w0 (<6) and high w0 (>6) regimes. Moreover, fluorescence anisotropy (steady-state and time-resolved) varies differently with respect to w0, before and after the transition point (w0 ∼ 8).
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Affiliation(s)
- Aparajita Phukon
- Department of Chemistry, Indian Institute of Technology Guwahati , Guwahati 781039, Assam, India
| | - Sudipta Ray
- Department of Chemistry, Indian Institute of Technology Guwahati , Guwahati 781039, Assam, India
| | - Kalyanasis Sahu
- Department of Chemistry, Indian Institute of Technology Guwahati , Guwahati 781039, Assam, India
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10
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Roy B, Satpathi S, Hazra P. Topological Influence of Lyotropic Liquid Crystalline Systems on Excited-State Proton Transfer Dynamics. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:3057-3065. [PMID: 26953966 DOI: 10.1021/acs.langmuir.5b04721] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
In the present work, we have investigated the excited-state proton transfer (ESPT) dynamics inside lipid-based reverse hexagonal (HII), gyroid Ia3d, and diamond Pn3m LLC phases. Polarized light microscopy (PLM) and small-angle X-ray scattering (SAXS) techniques have been employed for the characterization of LLC systems. Time-resolved fluorescence results reveal the retarded ESPT dynamics inside liquid crystalline systems compared to bulk water, and it follows the order HII < Ia3d < Pn3m < H2O. The slower solvation, hampered "Grotthuss" proton transfer process, and most importantly, topological influence, of the LLC systems are believed to be mainly responsible for the slower and different extent of ESPT dynamics. Interestingly, recombination dynamics is found to be faster with respect to bulk water and it follows the order H2O < Pn3m < Ia3d < HII. Faster recombination dynamics arises due to lower dielectric constant and different channel diameters of these LLC systems. However, the dissociation dynamics is found to be slower than bulk water and it follows the order HII < Ia3d < Pn3m < H2O. Differences in critical packing parameter of LLC systems are believed to be the governing factors for the slower dissociation dynamics in these liquid crystalline systems.
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Affiliation(s)
- Bibhisan Roy
- Department of Chemistry, Indian Institute of Science Education and Research (IISER) , Pune, 411008, Maharashtra, India
| | - Sagar Satpathi
- Department of Chemistry, Indian Institute of Science Education and Research (IISER) , Pune, 411008, Maharashtra, India
| | - Partha Hazra
- Department of Chemistry, Indian Institute of Science Education and Research (IISER) , Pune, 411008, Maharashtra, India
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11
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Park SY, Ghosh P, Park SO, Lee YM, Kwak SK, Kwon OH. Origin of ultraweak fluorescence of 8-hydroxyquinoline in water: photoinduced ultrafast proton transfer. RSC Adv 2016. [DOI: 10.1039/c5ra23802a] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Ultrafast excited-state proton transfer of 8-hydroxuquinoline to produce short-lived its tautomeric form causes immensely attenuated fluorescence in water.
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Affiliation(s)
- Sun-Young Park
- Center for Soft and Living Matter
- Institute for Basic Science (IBS)
- Ulsan 689-798
- Republic of Korea
| | - Prasun Ghosh
- Department of Chemistry
- Ulsan National Institute of Science and Technology (UNIST)
- Ulsan 689-798
- Republic of Korea
| | - Sung O. Park
- School of Energy and Chemical Engineering
- Ulsan National Institute of Science and Technology (UNIST)
- Ulsan 689-798
- Republic of Korea
| | - Young Min Lee
- Department of Chemistry
- Ulsan National Institute of Science and Technology (UNIST)
- Ulsan 689-798
- Republic of Korea
| | - Sang Kyu Kwak
- School of Energy and Chemical Engineering
- Ulsan National Institute of Science and Technology (UNIST)
- Ulsan 689-798
- Republic of Korea
| | - Oh-Hoon Kwon
- Center for Soft and Living Matter
- Institute for Basic Science (IBS)
- Ulsan 689-798
- Republic of Korea
- Department of Chemistry
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12
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Mondek J, Pekař M. The change in excited-state proton transfer kinetics of 1-naphthol i micelles upon the binding of polymers: The influence of hyaluronan hydration. Carbohydr Polym 2015; 129:168-74. [PMID: 26050902 DOI: 10.1016/j.carbpol.2015.04.060] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2015] [Revised: 04/20/2015] [Accepted: 04/29/2015] [Indexed: 11/29/2022]
Abstract
The fast deprotonation of 1-naphthol was studied in aqueous solution and in polymer-cetyltrimethylammonium bromide (CTAB) mixtures using picosecond fluorescence spectroscopy to study the influence of hyaluronan hydration in polymer-surfactant interactions. The aqueous micelle solution showed the expected change of proton transfer rate around the reported critical micelle concentration (∼1 mM). The proton transfer rate dependence on CTAB concentration in the hyaluronan-CTAB and polystyrenesulfonate-CTAB systems differed significantly from that in the aqueous micelle solution. The dynamic study of excited state proton transfer (ESPT) revealed the significant influence of hyaluronan hydration in CTAB micelles. When hyaluronan-CTAB aggregates were formed at the CTAB concentration of 0.5mM, a tenfold decrease in the rate of deprotonation was observed when compared to polystyrenesulfonate-CTAB aggregates due to hyaluronan hydration. In 2mM CTAB-hyaluronan aggregates, the rate of deprotonation was found to be almost two times faster than in the 2mM CTAB or polystyrenesulfonate-CTAB system. Furthermore, the study of excited-state proton transfer of 1-naphthol confirmed that hyaluronan hydration layer penetrates into the micelle and changes the emission characteristics of 1-naphthol.
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Affiliation(s)
- Jakub Mondek
- Brno University of Technology, Faculty of Chemistry, Institute of Physical and Applied Chemistry and Materials Research Centre, Purkyňova 464/118, 612 00 Brno, Czech Republic.
| | - Miloslav Pekař
- Brno University of Technology, Faculty of Chemistry, Institute of Physical and Applied Chemistry and Materials Research Centre, Purkyňova 464/118, 612 00 Brno, Czech Republic
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Joshi S, Pant DD. Interaction of quinine sulfate with anionic micelles of sodium dodecylsulfate: A time-resolved fluorescence spectroscopy at different pH. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2015; 148:49-59. [PMID: 25863459 DOI: 10.1016/j.saa.2015.03.115] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2014] [Revised: 03/13/2015] [Accepted: 03/27/2015] [Indexed: 06/04/2023]
Abstract
Photophysical behavior and rotational relaxation dynamics of quinine sulfate (QS) in anionic surfactant, sodium dodecylsulfate (SDS) at different pH have been studied using steady state and time resolved fluorescence spectroscopy. It has been observed that the cationic form of quinine sulfate (at pH 2) forms a fluorescent ion pair complex with the surfactant molecules at lower concentrations of surfactant. However, for higher concentrations of SDS, the probe molecules bind strongly with the micelles and reside at the water-micelle interface. At pH 7, QS is singly protonated in bulk aqueous solution. At lower concentrations of SDS aggregation between probe and surfactant molecules has been observed. However, for higher concentrations of SDS, an additional fluorescence peak corresponding to dicationic form of QS appears and this has been attributed to double protonation of the QS molecule in micellar solution. At pH 7, in the presence of SDS micelles, the photophysical properties of QS showed substantial changes compared to that in the bulk water solution. At pH 12, an increase in fluorescence intensity and lifetime has been observed and this has been attributed to the increase in radiative rate due to the incorporation of QS at the micelle-water interface. The local pH at micellar surface has been found different from the pH of bulk solution.
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Affiliation(s)
- Sunita Joshi
- Department of Physics, Birla Institute of Technology and Science, Pilani 333031, Rajasthan, India
| | - Debi D Pant
- Department of Physics, Birla Institute of Technology and Science, Pilani 333031, Rajasthan, India.
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14
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Basílio N, Laia CAT, Pina F. Excited-state proton transfer in confined medium. 4-methyl-7-hydroxyflavylium and β-naphthol incorporated in cucurbit[7]uril. J Phys Chem B 2014; 119:2749-57. [PMID: 25438065 DOI: 10.1021/jp511351w] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Excited-state proton transfer (ESPT) was studied by fluorescent emission using a mathematical model recast from the Weller theory. The titration curves can be fitted with three parameters: pK(a) (acidity constant of the ground sate), pK(ap)* (apparent acidity constant of the excited state), and η(A*), the efficiency of excited base formation from the excited acid. β-Naphthol and 4-metyhl-7-hydroxyflavylium were studied in aqueous solution and upon incorporation in cucurbit[7]uril. For all the compounds studied the interaction with the host leads to 1:1 adducts and the ground-state pK(a) increases upon incorporation. Whereas the ESPT of 4-methyl-7-hydroxyflavylium practically does not change in the presence of the host, in the case of β-naphthol it is prevented and the fluorescence emission titration curves are coincident with those taken by absorption. The position of the guest inside the host was investigated by NMR experiments and seems to determine the efficiency of the ESPT. The ESPT decreases for the guest, exhibiting a great protection of the phenol to the bulk water interaction.
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Affiliation(s)
- Nuno Basílio
- REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa , 2829-516 Monte de Caparica, Portugal
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15
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Seixas de Melo JS, Maçanita AL. Unveiling the Eigen-Weller ion pair from the excited state proton transfer kinetics of 3-chloro-4-methyl-7-hydroxycoumarin. J Phys Chem B 2014; 119:2604-10. [PMID: 25325432 DOI: 10.1021/jp508782h] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The prototropic reactions of the first excited singlet state of 3-chloro-4-methylumbelliferone (3Cl4MU), in dioxane:water mixtures (Dx:H2O), were revisited using ps-time-resolved fluorescence techniques. The data response to the dielectric constant of the mixtures revealed the presence of an additional fourth kinetic species, kinetically coupled to the neutral (N*), the tautomeric (T*), and anionic (A(-)*) forms of 3Cl4MU, which is assigned to the elusive geminate (A(-)*···H(+)) ion pair. From the data analysis, all rate constants of the prototropic and diffusion processes involved were separately evaluated. The results showed that, whenever the geminate ionic pair is not kinetically detected, the evaluated values for deprotonation and protonation rate constants can substantially deviate from the real ones, depending on the efficiencies of pair recombination and dissociation. Finally, the results provide convincing kinetic evidence for the Eigen-Weller mechanism (intermediacy of the geminate ionic pair) in a quasi-aqueous medium, which to our knowledge had not yet been given.
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Affiliation(s)
- J Sérgio Seixas de Melo
- Coimbra Chemistry Centre, Department of Chemistry, University of Coimbra , Rua Larga, 3004-535 Coimbra, Portugal
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Sen Mojumdar S, Chowdhury R, Mandal AK, Bhattacharyya K. In what time scale proton transfer takes place in a live CHO cell? J Chem Phys 2013; 138:215102. [PMID: 23758398 DOI: 10.1063/1.4807862] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Supratik Sen Mojumdar
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
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17
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Dynamics and prototropic reactivity of electronically excited states in simple surfactant aggregates. Curr Opin Colloid Interface Sci 2013. [DOI: 10.1016/j.cocis.2012.12.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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18
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Freitas AA, Maçanita AAL, Quina FH. Improved analysis of excited state proton transfer kinetics by the combination of standard and convolution methods. Photochem Photobiol Sci 2013; 12:902-10. [DOI: 10.1039/c3pp25445c] [Citation(s) in RCA: 12] [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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19
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Khorwal V, Datta A. Ground and excited state prototropism of 2-(4′-pyridyl)benzimidazole in micelles. J Photochem Photobiol A Chem 2012. [DOI: 10.1016/j.jphotochem.2012.08.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Mandal AK, Ghosh S, Das AK, Mondal T, Bhattacharyya K. Effect of NaCl on ESPT‐Mediated FRET in a CTAC Micelle: A Femtosecond and FCS Study. Chemphyschem 2012; 14:788-96. [PMID: 23143825 DOI: 10.1002/cphc.201200669] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Indexed: 02/01/2023]
Affiliation(s)
- Amit Kumar Mandal
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032 (India), Fax: (+91) 33‐2473‐2805
| | - Shirsendu Ghosh
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032 (India), Fax: (+91) 33‐2473‐2805
| | - Atanu Kumar Das
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032 (India), Fax: (+91) 33‐2473‐2805
| | - Tridib Mondal
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032 (India), Fax: (+91) 33‐2473‐2805
| | - Kankan Bhattacharyya
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032 (India), Fax: (+91) 33‐2473‐2805
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21
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Mondal T, Ghosh S, Das AK, Mandal AK, Bhattacharyya K. Salt Effect on the Ultrafast Proton Transfer in Niosome. J Phys Chem B 2012; 116:8105-12. [DOI: 10.1021/jp3043957] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Tridib Mondal
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur,
Kolkata 700032, India
| | - Shirsendu Ghosh
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur,
Kolkata 700032, India
| | - Atanu Kumar Das
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur,
Kolkata 700032, India
| | - Amit Kumar Mandal
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur,
Kolkata 700032, India
| | - Kankan Bhattacharyya
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur,
Kolkata 700032, India
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22
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Das R, Duportail G, Richert L, Klymchenko A, Mély Y. Sensing micelle hydration by proton-transfer dynamics of a 3-hydroxychromone dye: role of the surfactant headgroup and chain length. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:7147-7159. [PMID: 22515420 DOI: 10.1021/la300103a] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The dynamics of the excited-state intramolecular proton-transfer (ESIPT) reaction of 2-(2'-furyl)-3-hydroxychromone (FHC) was studied in micelles by time-resolved fluorescence. The proton-transfer dynamics of FHC was found to be sensitive to the hydration and charge of the micelles, demonstrated through a decrease of the ESIPT rate constant (k(PT)) in the sequence cationic → nonionic → anionic micelles. A remarkably slow ESIPT with a time constant (τ(PT)) of ~100 ps was observed in the anionic sodium dodecyl sulfate and sodium tetradecyl sulfate micelles, whereas it was quite fast (τ(PT) ≈ 15 ps) in the cationic cetyltrimethylammonium bromide and tetradecyltrimethylammonium bromide micelles. In the nonionic micelles of Brij-78, Brij-58, Tween-80, and Tween-20, ESIPT occurred with time constants (τ(PT) ≈ 35-65 ps) intermediate between those of the cationic and anionic micelles. The slower ESIPT dynamics in the anionic micelles than the cationic micelles is attributed to a relatively stronger hydration of the negatively charged headgroups of the former than the positively charged headgroups of the latter, which significantly weakens the intramolecular hydrogen bond of FHC in the Stern layer of the anionic micelles compared to the latter. In addition, electrostatic attraction between the positively charged -N(CH(3))(3)(+) headgroups and the negatively charged 4-carbonyl moiety of FHC effectively screens the intramolecular hydrogen bond from the perturbation of water molecules in the micelle-water interface of the cationic micelles, whereas in the anionic micelles, this screening of the intramolecular hydrogen bond is much less efficient due to an electrostatic repulsion between its negatively charged -OSO(3)(-) headgroups and the 4-carbonyl moiety. As for the nonionic micelles, a moderate level of hydration, and the absence of any charged headgroups, causes an ESIPT dynamics faster than that of the anionic but slower than that of the cationic micelles. Furthermore, the ESIPT rate decreased with a decrease of the hydrophobic chain length of the surfactants due to the stronger hydration of the micelles of shorter chain surfactants than those of longer chain surfactants, arising from a less compact packing of the former surfactants compared to the latter surfactants.
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Affiliation(s)
- Ranjan Das
- Department of Chemistry, West Bengal State University, Barasat, Kolkata 700126, India
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Orte A, Ruedas-Rama MJ, Paredes JM, Crovetto L, Alvarez-Pez JM. Dynamics of water-in-oil nanoemulsions revealed by fluorescence lifetime correlation spectroscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:12792-12799. [PMID: 21913723 DOI: 10.1021/la202004d] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The size, diffusional properties, and dynamics of reverse water-in-oil nanoemulsions, or reverse micelles (RMs), have been widely investigated because of interest in this system as a model for biological compartmentalization. Here, we have employed fluorescence lifetime correlation spectroscopy (FLCS) to reveal the dynamics and sizes of aerosol-OT (AOT)/isooctane RMs using a fluorescent xanthene derivative called Tokyo Green II (TG-II). The dye undergoes a partition and a shift in its tautomeric equilibrium such that the TG-II anion remains in the inner micellar aqueous core, and the neutral quinoid form lies in the interfacial region. By applying FLCS, we specifically obtained the lifetime filtered autocorrelation curves of the anionic TG-II, which shows a characteristic lifetime of approximately 4 ns. Analysis of the FLCS curves provides the diffusion coefficient and hydrodynamic radius of the RMs as well as micelle dynamics in the same experiment. The FLCS curves show dynamics in the microsecond time range, which represents an interconversion rate that changes the distribution of the TG-II neutral and anionic forms in the hydrophobic interface and the water core.
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Affiliation(s)
- Angel Orte
- Department of Physical Chemistry, Faculty of Pharmacy, Cartuja Campus, Granada University, 18071 Granada, Spain
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Freitas AA, Quina FH, Maçanita AAL. Picosecond Dynamics of Proton Transfer of a 7-Hydroxyflavylium Salt in Aqueous–Organic Solvent Mixtures. J Phys Chem A 2011; 115:10988-95. [DOI: 10.1021/jp2069754] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Adilson A. Freitas
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade Técnica de Lisboa, 1049-001 Lisbon, Portugal
| | - Frank H. Quina
- Instituto de Química and the USP Research Consortium for Photochemical Technology, Universidade de São Paulo, CP 26077, São Paulo 05513-970, Brazil
| | - António A. L. Maçanita
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade Técnica de Lisboa, 1049-001 Lisbon, Portugal
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Pina F, Melo MJ, Laia CAT, Parola AJ, Lima JC. Chemistry and applications of flavylium compounds: a handful of colours. Chem Soc Rev 2011; 41:869-908. [PMID: 21842035 DOI: 10.1039/c1cs15126f] [Citation(s) in RCA: 263] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Flavylium compounds are versatile molecules that comprise anthocyanins, the ubiquitous colorants used by Nature to confer colour to most flowers and fruits. They have found a wide range of applications in human technology, from the millenary colour paints described by the Roman architect Vitruvius, to their use as food additives, combining colour and antioxidant effects, and even as light absorbers in solar cells aiming at a greener solar energy conversion. Their rich complexity derives in part from their ability to switch between a variety of species (flavylium cations, neutral quinoidal bases, hemiketals and chalcones, and negatively charged phenolates) by means of external stimuli, such as pH, temperature and light. This critical review describes (i) the historical advancements in the understanding of the equilibria of their chemical reaction networks; (ii) their thermodynamics and kinetics; (iii) the mechanisms underlying their colour development, such as co-pigmentation and host-guest interactions; (iv) the photophysics and photochemistry that lead to photochromism; and (v) applications in solar cells, models for optical memories, photochromic soft materials such as ionic liquids and gels, and their properties in solid state materials (274 references).
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Affiliation(s)
- Fernando Pina
- REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
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Jankowski A, Wisniewski Ł, Jankowski A, Kluczyk A, Chmielewski P, Szemik-Hojniak A. Impact of micelle ionic electrical double layer structure on the excited state protolytic reaction in the fluorescent probe bound to the colloidal nanoparticles. J Phys Chem B 2011; 115:8078-87. [PMID: 21644566 DOI: 10.1021/jp110670j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The fluorescent probe, 2-hydroxynaphthalene(dodecylo)-6-sulfonamide (NSDA) bound selectively to shear plane of various electrostatic charges was synthesized and its photophysical properties have been investigated by means of steady state fluorescence and nanosecond time-resolved spectroscopy. Our experimental data allowed us to determine the excited state proton transfer (ESPT) rate and equilibrium constants of NSDA bound to micelles and to estimate the electric potential value (Ψ) at the particle surface. The spatial dependence of proton movement velocity through electric double layer (EDL) of micelles has been thoroughly analyzed. In this article, a new approach of estimating the values of the micelle potential (Ψ(R)) from the excited state proton transfer rate constant of the fluorescent probe bound at a certain distance (R) to a micellar surface has been proposed. The Ψ(R) values, obtained in this way, are compared with electrophoretic values of the particle potential (ζ). Our results on electrophoretic potentials and the reaction course of the ESPT in colloidal environment may contribute to a deeper understanding of micellar interactions and behavior of the living cells in contact with various diluted substances such as pharmacological drugs, hormones, proteins, and other colloidal particles.
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Park SY, Yu H, Park J, Jang DJ. Excited-state prototropic equilibrium dynamics of 6-hydroxyquinoline encapsulated in microporous catalytic faujasite zeolites. Chemistry 2011; 16:12609-15. [PMID: 20853278 DOI: 10.1002/chem.201000734] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The excited-state proton transfer and geminate recombination of 6-hydroxyquinoline (6HQ) encaged in catalytic Na(+)-exchanged faujasite zeolites X (NaX) and Y (NaY) have been explored by measuring steady-state and picosecond time-resolved spectra. The pathways and rate constants of proton transfer of excited 6HQ are determined by the microscopic environment of zeolitic hosts surrounding the guest molecules. The excited-state proton transfer of a 6HQ molecule encapsulated in a zeolitic nanocavity is initiated by deprotonation of the enolic group to form an anionic intermediate and completed by subsequent protonation of the imino group to form a zwitterionic tautomer. Geminate recombination occurs to compete with proton transfer at each tautomerization step of excited-state 6HQ because of the confined environment of dehydrated zeolitic supercages. Consequently, excited-state equilibria among three prototropic species of 6HQ are established in microporous catalytic faujasite zeolites. Kinetic differences in NaX and NaY are attributed to dissimilarities in acidity/basicity.
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Affiliation(s)
- Sun-Young Park
- School of Chemistry, Seoul National University, NS60, Seoul 151-742, Korea
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Farinhas J, Ferreira Q, Di Paolo RE, Alcácer L, Morgado J, Charas A. Nanostructured donor/acceptor interfaces in photovoltaic cells using columnar-grain films of a cross-linked poly(fluorene-alt-bithiophene). ACTA ACUST UNITED AC 2011. [DOI: 10.1039/c1jm10195a] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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31
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Sarangi MK, Basu S. Photophysical behavior of acridine with amines within the micellar microenvironment of SDS: a time-resolved fluorescence and laser flash photolysis study. Phys Chem Chem Phys 2011; 13:16821-30. [DOI: 10.1039/c1cp20844f] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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32
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Mondal T, Das AK, Sasmal DK, Bhattacharyya K. Excited State Proton Transfer in Ionic Liquid Mixed Micelles. J Phys Chem B 2010; 114:13136-42. [DOI: 10.1021/jp1058758] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tridib Mondal
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032, India
| | - Atanu Kumar Das
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032, India
| | - Dibyendu Kumar Sasmal
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032, India
| | - Kankan Bhattacharyya
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032, India
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Monteserín M, Burrows HD, Mallavia R, Di Paolo RE, Maçanita AL, Tapia MJ. How to change the aggregation in the DNA/surfactant/cationic conjugated polyelectrolyte system through the order of component addition: anionic versus neutral surfactants. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:11705-11714. [PMID: 20518566 DOI: 10.1021/la1011764] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The competitive interaction has been studied between double-stranded DNA (dsDNA), the cationic conjugated polyelectrolyte (CPE) poly[9,9-bis(6-N,N,N-trimethylamonium)hexyl)-fluorene-phenylene)] bromide (HTMA-PFP) and anionic or neutral surfactants (sodium dodecyl sulfonate, SDSu, and n-dodecyl pentaoxyethylene glycol ether, C(12)E(5)) in 4% (v/v) dimethyl sulfoxide (DMSO)-water using UV/visible absorption and fluorescence spectroscopy. Dramatic changes are observed in the spectroscopic behavior of the system depending on the order of addition of the reagents, the surfactant charge, and concentration range. If the neutral C(12)E(5) is added to the HTMA-PFP/dsDNA complex, no significant spectroscopic changes are observed. However, if SDSu is added to the same complex, a dramatic increase of the absorbance and emission intensity is observed for surfactant concentrations above the critical micelle concentration (cmc). In contrast, if dsDNA is added to HTMA-PFP/surfactant systems (with surfactant concentrations above their cmc) no significant changes are observed with SDSu, while a dramatic quenching of polymer emission is observed with C(12)E(5), which can be explained quantitatively in terms of HTMA-PFP/surfactant/DNA complexation and the subsequent polymer aggregation upon charge neutralization. The results are compared with those for the binary systems (HTMA-PFP/DNA and HTMA-PFP/surfactants) and indicate the importance of electrostatic interactions between HTMA-PFP and oppositely charged species in the aggregation processes.
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Affiliation(s)
- María Monteserín
- Departamento de Química, Universidad de Burgos, Burgos 09001, Spain
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Sen Mojumdar S, Mondal T, Das AK, Dey S, Bhattacharyya K. Ultrafast and ultraslow proton transfer of pyranine in an ionic liquid microemulsion. J Chem Phys 2010; 132:194505. [DOI: 10.1063/1.3428669] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Freitas AA, Quina FH, Fernandes AC, Maçanita AAL. Picosecond Dynamics of the Prototropic Reactions of 7-Hydroxyflavylium Photoacids Anchored at an Anionic Micellar Surface. J Phys Chem A 2010; 114:4188-96. [DOI: 10.1021/jp100281u] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Adilson A. Freitas
- Departamento Engenharia Química, Centro de Química Estrutural, IST/UTL, Lisbon 1049-001, Portugal, Instituto de Química, Universidade de São Paulo, CP 26077, São Paulo 05513-970, Brazil
| | - Frank H. Quina
- Departamento Engenharia Química, Centro de Química Estrutural, IST/UTL, Lisbon 1049-001, Portugal, Instituto de Química, Universidade de São Paulo, CP 26077, São Paulo 05513-970, Brazil
| | - Ana C. Fernandes
- Departamento Engenharia Química, Centro de Química Estrutural, IST/UTL, Lisbon 1049-001, Portugal, Instituto de Química, Universidade de São Paulo, CP 26077, São Paulo 05513-970, Brazil
| | - António A. L. Maçanita
- Departamento Engenharia Química, Centro de Química Estrutural, IST/UTL, Lisbon 1049-001, Portugal, Instituto de Química, Universidade de São Paulo, CP 26077, São Paulo 05513-970, Brazil
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Quina FH, Moreira PF, Vautier-Giongo C, Rettori D, Rodrigues RF, Freitas AA, Silva PF, Maçanita AL. Photochemistry of anthocyanins and their biological role in plant tissues. PURE APPL CHEM 2009. [DOI: 10.1351/pac-con-08-09-28] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Anthocyanins, the major red, purple, and blue pigments of plants, absorb visible as well as UV radiation and are effective antioxidants and scavengers of active oxygen species. In plant leaves, one of the functional roles proposed for anthocyanins is protection of the photosynthetic apparatus from the effects of excess incident visible or UV-B radiation and photooxidative stress. In essence, a photoprotective role requires that the excited singlet states of both complexed and uncomplexed anthocyanins deactivate back to the ground state so quickly that intersystem crossing, photoreaction, and diffusion-controlled quenching processes cannot compete. Studies of the photochemical properties of synthetic analogs of anthocyanins and of several naturally occurring anthocyanins show that this is indeed the case, uncomplexed anthocyanins decaying back to the ground state via fast (subnanosecond) excited-state proton transfer (ESPT) and anthocyanin-copigment complexes by fast (subpicosecond) charge-transfer-mediated internal conversion.
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Affiliation(s)
- Frank H. Quina
- 1Instituto de Química, Universidade de São Paulo, CP 26790, São Paulo 05513-970, Brazil
| | - Paulo F. Moreira
- 1Instituto de Química, Universidade de São Paulo, CP 26790, São Paulo 05513-970, Brazil
| | - Carolina Vautier-Giongo
- 2Departamento de Ciências Exatas e da Terra, Universidade Federal de São Paulo, Diadema, SP, Brazil
| | - Daniel Rettori
- 2Departamento de Ciências Exatas e da Terra, Universidade Federal de São Paulo, Diadema, SP, Brazil
| | - Rita F. Rodrigues
- 4Centro de Química Estrutural, Instituto Superior Técnico, Technical University of Lisbon, Portugal
| | - Adilson A. Freitas
- 4Centro de Química Estrutural, Instituto Superior Técnico, Technical University of Lisbon, Portugal
| | - Palmira F. Silva
- 4Centro de Química Estrutural, Instituto Superior Técnico, Technical University of Lisbon, Portugal
| | - António L. Maçanita
- 4Centro de Química Estrutural, Instituto Superior Técnico, Technical University of Lisbon, Portugal
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Choudhury SD, Pal H. Modulation of Excited-State Proton-Transfer Reactions of 7-Hydroxy-4-methylcoumarin in Ionic and Nonionic Reverse Micelles. J Phys Chem B 2009; 113:6736-44. [DOI: 10.1021/jp8111759] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
| | - Haridas Pal
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
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38
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Rodrigues RF, da Silva PF, Shimizu K, Freitas AA, Kovalenko SA, Ernsting NP, Quina FH, Maçanita A. Ultrafast internal conversion in a model anthocyanin-polyphenol complex: implications for the biological role of anthocyanins in vegetative tissues of plants. Chemistry 2009; 15:1397-402. [PMID: 19072804 DOI: 10.1002/chem.200801207] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The red flavylium cations of anthocyanins form ground-state charge-transfer complexes with several naturally occurring electron-donor copigments, such as hydroxylated flavones and hydroxycinnamic or benzoic acids. Excitation of the 7-methoxy-4-methyl-flavylium-protocatechuic acid complex results in ultrafast (240 fs) internal conversion to the ground state of the complex by way of a low-lying charge-transfer state. Thus, both uncomplexed anthocyanins, whose excited state decays by fast (5-20 ps) excited-state proton transfer, and anthocyanin-copigment complexes have highly efficient mechanisms of deactivation that are consistent with the proposed protective role of anthocyanins against excess solar radiation in the vegetative tissues of plants.
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Affiliation(s)
- Rita França Rodrigues
- Centro de Química Estrutural, Technical University Lisbon, Av. Rovisco Pais s/n, 1049-001 Lisbon, Portugal
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39
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Pina J, Seixas de Melo J, Burrows HD, Maçanita AL, Galbrecht F, Bünnagel T, Scherf U. Alternating Binaphthyl−Thiophene Copolymers: Synthesis, Spectroscopy, and Photophysics and Their Relevance to the Question of Energy Migration versus Conformational Relaxation. Macromolecules 2009. [DOI: 10.1021/ma802395c] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- J. Pina
- Department of Chemistry, University of Coimbra, Rua Larga, 3004-535 Coimbra, Portugal, Departamento de Engenharia Química e Biológica, Centro de Química Estrutural, Instituto Superior Técnico, Av. Rovisco Pais, s/n. Lisboa, Portugal, and Makromolekulare Chemie, Bergische Universität Wuppertal, Gaussstr. 20, 42097 Wuppertal, Germany
| | - J. Seixas de Melo
- Department of Chemistry, University of Coimbra, Rua Larga, 3004-535 Coimbra, Portugal, Departamento de Engenharia Química e Biológica, Centro de Química Estrutural, Instituto Superior Técnico, Av. Rovisco Pais, s/n. Lisboa, Portugal, and Makromolekulare Chemie, Bergische Universität Wuppertal, Gaussstr. 20, 42097 Wuppertal, Germany
| | - H. D. Burrows
- Department of Chemistry, University of Coimbra, Rua Larga, 3004-535 Coimbra, Portugal, Departamento de Engenharia Química e Biológica, Centro de Química Estrutural, Instituto Superior Técnico, Av. Rovisco Pais, s/n. Lisboa, Portugal, and Makromolekulare Chemie, Bergische Universität Wuppertal, Gaussstr. 20, 42097 Wuppertal, Germany
| | - A. L. Maçanita
- Department of Chemistry, University of Coimbra, Rua Larga, 3004-535 Coimbra, Portugal, Departamento de Engenharia Química e Biológica, Centro de Química Estrutural, Instituto Superior Técnico, Av. Rovisco Pais, s/n. Lisboa, Portugal, and Makromolekulare Chemie, Bergische Universität Wuppertal, Gaussstr. 20, 42097 Wuppertal, Germany
| | - F. Galbrecht
- Department of Chemistry, University of Coimbra, Rua Larga, 3004-535 Coimbra, Portugal, Departamento de Engenharia Química e Biológica, Centro de Química Estrutural, Instituto Superior Técnico, Av. Rovisco Pais, s/n. Lisboa, Portugal, and Makromolekulare Chemie, Bergische Universität Wuppertal, Gaussstr. 20, 42097 Wuppertal, Germany
| | - T. Bünnagel
- Department of Chemistry, University of Coimbra, Rua Larga, 3004-535 Coimbra, Portugal, Departamento de Engenharia Química e Biológica, Centro de Química Estrutural, Instituto Superior Técnico, Av. Rovisco Pais, s/n. Lisboa, Portugal, and Makromolekulare Chemie, Bergische Universität Wuppertal, Gaussstr. 20, 42097 Wuppertal, Germany
| | - U. Scherf
- Department of Chemistry, University of Coimbra, Rua Larga, 3004-535 Coimbra, Portugal, Departamento de Engenharia Química e Biológica, Centro de Química Estrutural, Instituto Superior Técnico, Av. Rovisco Pais, s/n. Lisboa, Portugal, and Makromolekulare Chemie, Bergische Universität Wuppertal, Gaussstr. 20, 42097 Wuppertal, Germany
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Di Paolo RE, Burrows HD, Morgado J, Maçanita AL. Photodynamics of a PV Trimer in High-Viscosity Solvents and in PMMA Films: A New Insight into Energy Transfer versus Conformational Relaxation in Conjugated Polymers. Chemphyschem 2009; 10:448-54. [DOI: 10.1002/cphc.200800554] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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41
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Crystal structure, spectroscopic, and theoretical studies of 2-methylamino-6-methyl-4 nitropyridine N-oxide. J Mol Struct 2009. [DOI: 10.1016/j.molstruc.2008.10.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Monteserín M, Burrows HD, Valente AJM, Mallavia R, Di Paolo RE, Maçanita AL, Tapia MJ. Interaction between Poly(9,9-bis(6′-N,N,N-trimethylammonium)hexyl)fluorene phenylene) Bromide and DNA as Seen by Spectroscopy, Viscosity, and Conductivity: Effect of Molecular Weights and DNA Secondary Structure. J Phys Chem B 2009; 113:1294-1302. [DOI: 10.1021/jp806353y] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- María Monteserín
- Departamento de Química, Universidad de Burgos, Plaza Misael Bañuelos, Burgos 09001, Spain, Departamento de Química, Universidade de Coimbra, 3004-535 Coimbra, Portugal, Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, Elche 03202, Alicante, Spain, and Departamento de Engenharia Química e Biologica, Instituto Superior Técnico (IST), Avenida Rovisco Pais, P1049-001, Lisboa, Portugal
| | - Hugh D. Burrows
- Departamento de Química, Universidad de Burgos, Plaza Misael Bañuelos, Burgos 09001, Spain, Departamento de Química, Universidade de Coimbra, 3004-535 Coimbra, Portugal, Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, Elche 03202, Alicante, Spain, and Departamento de Engenharia Química e Biologica, Instituto Superior Técnico (IST), Avenida Rovisco Pais, P1049-001, Lisboa, Portugal
| | - Artur J. M. Valente
- Departamento de Química, Universidad de Burgos, Plaza Misael Bañuelos, Burgos 09001, Spain, Departamento de Química, Universidade de Coimbra, 3004-535 Coimbra, Portugal, Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, Elche 03202, Alicante, Spain, and Departamento de Engenharia Química e Biologica, Instituto Superior Técnico (IST), Avenida Rovisco Pais, P1049-001, Lisboa, Portugal
| | - Ricardo Mallavia
- Departamento de Química, Universidad de Burgos, Plaza Misael Bañuelos, Burgos 09001, Spain, Departamento de Química, Universidade de Coimbra, 3004-535 Coimbra, Portugal, Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, Elche 03202, Alicante, Spain, and Departamento de Engenharia Química e Biologica, Instituto Superior Técnico (IST), Avenida Rovisco Pais, P1049-001, Lisboa, Portugal
| | - Roberto E. Di Paolo
- Departamento de Química, Universidad de Burgos, Plaza Misael Bañuelos, Burgos 09001, Spain, Departamento de Química, Universidade de Coimbra, 3004-535 Coimbra, Portugal, Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, Elche 03202, Alicante, Spain, and Departamento de Engenharia Química e Biologica, Instituto Superior Técnico (IST), Avenida Rovisco Pais, P1049-001, Lisboa, Portugal
| | - Antonio L. Maçanita
- Departamento de Química, Universidad de Burgos, Plaza Misael Bañuelos, Burgos 09001, Spain, Departamento de Química, Universidade de Coimbra, 3004-535 Coimbra, Portugal, Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, Elche 03202, Alicante, Spain, and Departamento de Engenharia Química e Biologica, Instituto Superior Técnico (IST), Avenida Rovisco Pais, P1049-001, Lisboa, Portugal
| | - María J. Tapia
- Departamento de Química, Universidad de Burgos, Plaza Misael Bañuelos, Burgos 09001, Spain, Departamento de Química, Universidade de Coimbra, 3004-535 Coimbra, Portugal, Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, Elche 03202, Alicante, Spain, and Departamento de Engenharia Química e Biologica, Instituto Superior Técnico (IST), Avenida Rovisco Pais, P1049-001, Lisboa, Portugal
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Gohain B, Boruah B, Saikia PM, Dutta RK. Premicellar and micelle formation behavior of aqueous anionic surfactants in the presence of triphenylmethane dyes: protonation of dye in ion pair micelles. J PHYS ORG CHEM 2009. [DOI: 10.1002/poc.1603] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Mukhopadhyay M, Mandal A, Banerjee D, Bhattacharyya SP, Mukherjee S. Effect of surfactant-perturbed nanocaging on the ground and excited state proton transfer reaction. J Phys Chem A 2008; 112:12543-9. [PMID: 19007198 DOI: 10.1021/jp806211v] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The effect of mixed cyclodextrin-surfactant systems on the ground and excited state proton transfer reactions of 4-methyl-2,6-diformylphenol (MFOH) in aqueous solution has been investigated by steady state and time-resolved fluorescence spectroscopy. It has been found that micellar media perturbs the solvation of MFOH and facilitates nanocaging. In the presence of micelle, MFOH preferentially resides in the interfacial region. Depending on the local pH due to compartmentalization of reaction media, normal or anionic form of MFOH dominates. Encapsulation of the probe within the cyclodextrin nanocavity enhances the shorter lifetime component of MFOH unexpectedly, which has been explained on the basis of reduced solvation and reduced dipolar effect due to confinement.
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Affiliation(s)
- M Mukhopadhyay
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata-700032, India
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45
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Di Paolo RE, Gigante B, Esteves MA, Pires N, Santos C, Lameiro MH, Seixas de Melo J, Burrows HD, Maçanita AL. Picosecond Structural Relaxation of Abietic Acid Based Amine End CappedPara-Phenylenevinylene Trimers in Solution. Chemphyschem 2008; 9:2214-20. [DOI: 10.1002/cphc.200800374] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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46
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Understanding the photophysics of 4-nitro-1-hydroxy-2-naphthoic acid: A controlled excited state proton transfer. Chem Phys 2008. [DOI: 10.1016/j.chemphys.2008.06.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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47
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Excited state proton transfer of pyranine in octadecylamine Langmuir–Blodgett films of different structures. Chem Phys Lett 2008. [DOI: 10.1016/j.cplett.2008.01.085] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Lee YS, Kwon OH, Park HJ, Franz J, Jang DJ. Excited-state proton transfer and geminate recombination in the molecular cage of β-cyclodextrin. J Photochem Photobiol A Chem 2008. [DOI: 10.1016/j.jphotochem.2007.07.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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49
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Pina J, Seixas de Melo J, Burrows HD, Galbrecht F, Bilge A, Kudla CJ, Scherf U. Excited State Properties of Oligophenyl and Oligothienyl Swivel Cruciforms. J Phys Chem B 2008; 112:1104-11. [DOI: 10.1021/jp0773280] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- J. Pina
- Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal, and Makromolekulare Chemie, Bergische Universität Wuppertal, Gauβstr. 20, 42097 Wuppertal, Germany
| | - J. Seixas de Melo
- Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal, and Makromolekulare Chemie, Bergische Universität Wuppertal, Gauβstr. 20, 42097 Wuppertal, Germany
| | - H. D. Burrows
- Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal, and Makromolekulare Chemie, Bergische Universität Wuppertal, Gauβstr. 20, 42097 Wuppertal, Germany
| | - F. Galbrecht
- Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal, and Makromolekulare Chemie, Bergische Universität Wuppertal, Gauβstr. 20, 42097 Wuppertal, Germany
| | - A. Bilge
- Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal, and Makromolekulare Chemie, Bergische Universität Wuppertal, Gauβstr. 20, 42097 Wuppertal, Germany
| | - C. J. Kudla
- Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal, and Makromolekulare Chemie, Bergische Universität Wuppertal, Gauβstr. 20, 42097 Wuppertal, Germany
| | - U. Scherf
- Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal, and Makromolekulare Chemie, Bergische Universität Wuppertal, Gauβstr. 20, 42097 Wuppertal, Germany
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50
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Park SY, Lee YS, Jang DJ. Excited-state proton-transfer dynamics of 1-methyl-6-hydroxyquinolinium embedded in a solid matrix of poly(2-hydroxyethyl methacrylate). Phys Chem Chem Phys 2008; 10:6703-7. [DOI: 10.1039/b811180d] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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