1
|
Phillips D, Dhami S, Ostler R, Petrasek Z. The Dimerisation of Phthalocyanines. PROGRESS IN REACTION KINETICS AND MECHANISM 2019. [DOI: 10.3184/007967403322807390] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In this review, we have shown that the dimerisation of phthalocyanine compounds, notably here the sulphonated aluminium phthalocyanines, is dependent upon concentration, on the medium in which the dye is dissolved, and upon pH. Complex equilibria between various monomer and dimer species are observed as a function of pH, and the probable structures of the dimers elucidated by semi-empirical and ab initio calculations. The formation of a red-shifted dimer leads to the quenching of monomer singlet state in concentrated solution, in reverse micelles, and in lipid vesicles, and this behaviour can account for the fluorescence intensity distributions and decay characteristics of phthalocyanine dyes in living cells as a function of irradiation time.
Collapse
Affiliation(s)
- David Phillips
- Department of Chemistry, Imperial College London, Exhibition Road, London SW7 1AZ, UK
| | - Suman Dhami
- Department of Chemistry, Imperial College London, Exhibition Road, London SW7 1AZ, UK
| | - Richard Ostler
- Department of Chemistry, Imperial College London, Exhibition Road, London SW7 1AZ, UK
| | - Zdenek Petrasek
- Department of Chemistry, Imperial College London, Exhibition Road, London SW7 1AZ, UK
| |
Collapse
|
2
|
Iehl J, Nierengarten JF, Harriman A, Bura T, Ziessel R. Artificial light-harvesting arrays: electronic energy migration and trapping on a sphere and between spheres. J Am Chem Soc 2011; 134:988-98. [PMID: 22148681 DOI: 10.1021/ja206894z] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
A sophisticated model of the natural light-harvesting antenna has been devised by decorating a C(60) hexa-adduct with ten yellow and two blue boron dipyrromethene (Bodipy) dyes in such a way that the dyes retain their individuality and assist solubility of the fullerene. Unusually, the fullerene core is a poor electron acceptor and does not enter into light-induced electron-transfer reactions with the appended dyes, but ineffective electronic energy transfer from the excited-state dye to the C(60) residue competes with fluorescence from the yellow dye. Intraparticle electronic energy transfer from yellow to blue dyes can be followed by steady-state and time-resolved fluorescence spectroscopy and by excitation spectra for isolated C(60) nanoparticles dissolved in dioxane at 293 K and at 77 K. The decorated particles can be loaded into polymer films by spin coating from solution. In the dried film, efficient energy transfer occurs such that photons absorbed by the yellow dye are emitted by the blue dye. Films can also be prepared to contain C(60) nanoparticles loaded with the yellow Bodipy dye but lacking the blue dye and, under these circumstances, electronic energy migration occurs between yellow dyes appended to the same nanoparticle and, at higher loading, to dye molecules on nearby particles. Doping these latter polymer films with the mixed-dye nanoparticle coalesces these multifarious processes in a single system. Thus, long-range energy migration occurs among yellow dyes attached to different particles before trapping at a blue dye. In this respect, the film resembles the natural photosynthetic light-harvesting complexes, albeit at much reduced efficacy. The decorated nanoparticles sensitize amorphous silicon photocells.
Collapse
Affiliation(s)
- Julien Iehl
- Laboratoire de Chimie des Matériaux Moléculaires, Université de Strasbourg et CNRS (UMR 7509), Ecole Européenne de Chimie, Polymères et Matériaux, 25 rue Becquerel, 67087 Strasbourg Cedex 02, France
| | | | | | | | | |
Collapse
|
3
|
Carter Ramirez DM, Ding J, Guan J, Vobornik D, Carnini A, Ogilvie WW, Jakubek ZJ, Johnston LJ. A Förster resonance energy transfer (FRET) approach for enhancing fluorescence contrast in phase-separated membranes. CAN J CHEM 2011. [DOI: 10.1139/v10-144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The partitioning of the dye-labeled lipid probe, NBD-DHPE (1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-(7-nitro-2-1,3-benzoxadiazol-4-yl) (ammonium salt)), was examined by fluorescence microscopy in phase-separated lipid bilayers with mixtures of coexisting liquid-ordered and fluid phases. This probe shows slightly higher fluorescence intensity in the ordered domains but undergoes a contrast reversal to give a more strongly fluorescent fluid phase in the presence of >0.2% Texas red-DHPE (TR-DHPE). The change in contrast is shown to result from Förster resonance energy transfer between the NBD donor and TR acceptor in the fluid phase, which has a TR concentration that is approximately 3 times higher than in the domains. An alternate approach using a nitroxide-substituted lipid that partitions into the fluid phase as a quencher, was also examined as a means to enhance the contrast; however, the quencher modified the behaviour of the bilayer. The energy transfer method for enhancing the contrast between ordered and fluid phases was used to examine the morphology of enzyme-treated bilayers.
Collapse
Affiliation(s)
- Daniel M. Carter Ramirez
- Steacie Institute for Molecular Sciences, National Research Council Canada, Ottawa, K1A 0R6 ON, Canada
- Department of Chemistry, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Jason Ding
- Steacie Institute for Molecular Sciences, National Research Council Canada, Ottawa, K1A 0R6 ON, Canada
- Department of Chemistry, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Jack Guan
- Steacie Institute for Molecular Sciences, National Research Council Canada, Ottawa, K1A 0R6 ON, Canada
- Department of Chemistry, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Dusan Vobornik
- Steacie Institute for Molecular Sciences, National Research Council Canada, Ottawa, K1A 0R6 ON, Canada
- Department of Chemistry, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Anna Carnini
- Steacie Institute for Molecular Sciences, National Research Council Canada, Ottawa, K1A 0R6 ON, Canada
- Department of Chemistry, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - William W. Ogilvie
- Steacie Institute for Molecular Sciences, National Research Council Canada, Ottawa, K1A 0R6 ON, Canada
- Department of Chemistry, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Zygmunt J. Jakubek
- Steacie Institute for Molecular Sciences, National Research Council Canada, Ottawa, K1A 0R6 ON, Canada
- Department of Chemistry, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Linda J. Johnston
- Steacie Institute for Molecular Sciences, National Research Council Canada, Ottawa, K1A 0R6 ON, Canada
- Department of Chemistry, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| |
Collapse
|
4
|
Seth D, Chakraborty A, Setua P, Chakrabarty D, Sarkar N. Study of Energy Transfer from 7-Amino Coumarin Donors to the Rhodamine 6G Acceptor in Lecithin Vesicles and Sodium Taurocholate−Lecithin Mixed Aggregates. J Phys Chem B 2005; 109:12080-5. [PMID: 16852490 DOI: 10.1021/jp050812n] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The energy transfer using 7-amino coumarin dyes as the donor and rhodamine 590 (Rh6G) as the acceptor was investigated in lecithin vesicles and sodium taurocholate (NaTC)-lecithin mixed aggregates using steady-state and time-resolved fluorescence spectroscopy. All energy transfer parameters were calculated. The coumarin 153-Rh6G pair is the most efficient donor-acceptor pair as reflected by the value of k(ET). With addition of NaTC in lecithin, in the case of the coumarin 153-Rh6G pair, the energy transfer rate or efficiency does not change very much, whereas in the case of the coumarin 151-Rh6G pair, the energy transfer rate decreases 2-fold upon going from lecithin vesicles to NaTC-lecithin mixed aggregates where the molar ratio is 2.5. It is mainly due to the deeper location of coumarin 153 in the lipid bilayer or in mixed aggregates. Rotational relaxation data also support this idea.
Collapse
Affiliation(s)
- Debabrata Seth
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721 302, WB, India
| | | | | | | | | |
Collapse
|
5
|
Klushin L, Tcherkasskaya O. Effects of molecular distribution on the fluorescence transfer: Exact results for slab geometry. J Chem Phys 2003. [DOI: 10.1063/1.1589472] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
6
|
Tcherkasskaya O, Gronenborn AM, Klushin L. Excluded volume effect within the continuous model for the fluorescence energy transfer. Biophys J 2002; 83:2826-34. [PMID: 12414714 PMCID: PMC1302366 DOI: 10.1016/s0006-3495(02)75291-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
We consider and discuss the transfer of electronic energy between donor and acceptor molecules, both continuously distributed in an infinite space. In particular, the ensemble-average fluorescence intensity decay for the donor was calculated, taking into account the excluded volume. The latter may be associated either with finite molecular size or any other spatial restrictions, which are imposed on fluorophore distribution by a superstructure. Results show that in a system using excluded volume, the time dependence in donor decay is more complex compared to that predicted by a simplified stretched exponential model. We identify a crossover between two distinct time regimes in the refined decay and demonstrate its correlation with two competing parameters: r(m), which characterizes the minimal distance between interacting molecules, and R(0), which is related to the strength of the molecular interactions. In this context, the "apparent dimensionality" of the energy transfer recovered from the stretched exponential model ignores the crossover, and may be quite misleading. Basic theoretical considerations to that end are provided.
Collapse
Affiliation(s)
- Olga Tcherkasskaya
- Department of Biochemistry and Molecular Biology, Medical Center, Georgetown University School of Medicine, 3900 Reservoir Road NW, Washington, DC 20007-2197, USA.
| | | | | |
Collapse
|
7
|
|
8
|
Tcherkasskaya O, Klushin L, Gronenborn AM. Effective lattice behavior of fluorescence energy transfer at lamellar macromolecular interfaces. Biophys J 2002; 82:988-95. [PMID: 11806938 PMCID: PMC1301905 DOI: 10.1016/s0006-3495(02)75458-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Fluorescence energy transfer between donors and acceptors confined to macromolecular interfaces is considered. In particular, we discuss two theoretical models for the ensemble-average fluorescence intensity decay of the donor when both fluorophores are incorporated into a planar (e.g., lamellar) interface. The first model is based on a continuous distribution of donor and acceptor molecules on a two-dimensional surface, whereas the other assumes a discrete distribution of fluorophores along the nodes of a two-dimensional square lattice. Results for the discrete model show that the fluorescence intensity kinetics of a donor depends strongly on the geometry of the molecular distribution (i.e., the lattice constant) and the photophysics of fluorophores (i.e., critical radius of the energy transfer). Furthermore, a "discrete molecular distribution" might manifest itself in the experimental data as an increase in the apparent dimensionality of the energy transfer with increasing acceptor concentration. Altogether, the experimental and theoretical underpinnings indicate the enormous potential of using fluorescence energy-transfer kinetics for revealing structural features of molecular ensembles (i.e., geometry, shape) based on a single experimental measurement. However, further understanding the effects of restricted geometries on the fluorescence energy transfer is required to take full advantage of this information. Basic theoretical considerations to that end are provided.
Collapse
Affiliation(s)
- Olga Tcherkasskaya
- Laboratory of Experimental and Computational Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
| | | | | |
Collapse
|
9
|
Loura LM, Fedorov A, Prieto M. Fluid-fluid membrane microheterogeneity: a fluorescence resonance energy transfer study. Biophys J 2001; 80:776-88. [PMID: 11159445 PMCID: PMC1301276 DOI: 10.1016/s0006-3495(01)76057-2] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Large unilamellar vesicles of dimyristoylphosphatidylcholine/cholesterol mixtures were studied using fluorescence techniques (steady-state fluorescence intensity and anisotropy, fluorescence lifetime, and fluorescence resonance energy transfer (FRET)). Three compositions (cholesterol mole fraction 0.15, 0.20, and 0.25) and two temperatures (30 and 40 degrees C) inside the coexistence range of liquid-ordered (l(o)) and liquid-disordered (l(d)) phases were investigated. Two common membrane probes, N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)-dimyristoylphosphatidylethanolamine (NBD-DMPE) and N-(lissamine(TM)-rhodamine B)-dimyristoylphosphatidylethanolamine (Rh-DMPE), which form a FRET pair, were used. The l(o)/l(d) partition coefficients of the probes were determined by individual photophysical measurements and global analysis of time-resolved FRET decays. Although the acceptor, Rh-DMPE, prefers the l(d) phase, the opposite is observed for the donor, NBD-DMPE. Accordingly, FRET efficiency decreases as a consequence of phase separation. Comparing the independent measurements of partition coefficient, it was possible to detect very small domains (<20 nm) of l(o) in the cholesterol-poor end of the phase coexistence range. In contrast, domains of l(d) in the cholesterol-rich end of the coexistence range have comparatively large size. These observations are probably related to different processes of phase separation, nucleation being preferred in formation of l(o) phase from initially pure l(d), and domain growth being faster in formation of l(d) phase from initially pure l(o).
Collapse
Affiliation(s)
- L M Loura
- Centro de Química-Física Molecular, Instituto Superior Técnico, P-1049-001 Lisboa, Portugal.
| | | | | |
Collapse
|
10
|
Loura LMS, Fedorov A, Prieto M. Membrane Probe Distribution Heterogeneity: A Resonance Energy Transfer Study. J Phys Chem B 2000. [DOI: 10.1021/jp000246q] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Luís M. S. Loura
- Centro de Química-Física Molecular, Instituto Superior Técnico, P-1049-001 Lisboa, Portugal, and Departamento de Química, Universidade de Évora, Rua Romão Ramalho, 59, P-7000−671 Évora, Portugal
| | - Aleksandre Fedorov
- Centro de Química-Física Molecular, Instituto Superior Técnico, P-1049-001 Lisboa, Portugal, and Departamento de Química, Universidade de Évora, Rua Romão Ramalho, 59, P-7000−671 Évora, Portugal
| | - Manuel Prieto
- Centro de Química-Física Molecular, Instituto Superior Técnico, P-1049-001 Lisboa, Portugal, and Departamento de Química, Universidade de Évora, Rua Romão Ramalho, 59, P-7000−671 Évora, Portugal
| |
Collapse
|
11
|
Photophysical studies of aerosol-OT films loaded with biological macromolecules and made from reverse micelles. Colloid Polym Sci 1997. [DOI: 10.1007/bf01188935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
12
|
Avramiotis S, Bekiari V, Lianos P, Xenakis A. Structural and Dynamic Properties of Lecithin-Alcohol Based w/o Microemulsions: A Luminescence Quenching Study. J Colloid Interface Sci 1997; 194:326-31. [PMID: 9398413 DOI: 10.1006/jcis.1997.5135] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Water-in-oil microemulsions have been made with lecithin in the presence of some alcohols. The structure of the microemulsions has been studied by steady-state and time-resolved analysis of the luminescence quenching of Ru(bipy)32+ by Fe(CN)63-. We found that well-defined microemulsions can be made only in the presence of short-chain alcohols such as propanol-1 and butanol-1. There exists a threshold for water content in order to obtain typical reverse micelles. Thus in the case of propanol-1, water/surfactant ratio wo should be above 20. By varying water content in the range 20 < wo </= 40, the microemulsion droplets suffer dramatic structural changes and the system passes through a percolation threshold. Copyright 1997 Academic Press. Copyright 1997Academic Press
Collapse
Affiliation(s)
- S Avramiotis
- Institute of Biological Research and Biotechnology, National Hellenic Research Foundation, 48 Vas. Constantinou Avenue, Athens, 11635, Greece
| | | | | | | |
Collapse
|