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Sailaja STN, Maisuls I, Hepp A, Brünink D, Doltsinis NL, Faust A, Hermann S, Strassert CA. Dual Emissive Zn(II) Naphthalocyanines: Synthesis, Structural and Photophysical Characterization with Theory-Supported Insights towards Soluble Coordination Compounds with Visible and Near-Infrared Emission. Int J Mol Sci 2024; 25:2605. [PMID: 38473852 DOI: 10.3390/ijms25052605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 02/09/2024] [Accepted: 02/14/2024] [Indexed: 03/14/2024] Open
Abstract
Metal phthalocyaninates and their higher homologues are recognized as deep-red luminophores emitting from their lowest excited singlet state. Herein, we report on the design, synthesis, and in-depth characterization of a new class of dual-emissive (visible and NIR) metal naphthalocyaninates. A 4-N,N-dimethylaminophen-4-yl-substituted naphthalocyaninato zinc(II) complex (Zn-NMe2Nc) and the derived water-soluble coordination compound (Zn-NMe3Nc) exhibit a near-infrared fluorescence from the lowest ligand-centered state, along with a unique push-pull-supported luminescence in the visible region of the electromagnetic spectrum. An unprecedentedly broad structural (2D-NMR spectroscopy and mass spectrometry) as well as photophysical characterization (steady-state state and time-resolved photoluminescence spectroscopy) is presented. The unique dual emission was assigned to two independent sets of singlet states related to the intrinsic Q-band of the macrocycle and to the push-pull substituents in the molecular periphery, respectively, as predicted by TD-DFT calculations. In general, the elusive chemical aspects of these macrocyclic compounds are addressed, involving both reaction conditions, thorough purification, and in-depth characterization. Besides the fundamental aspects that are investigated herein, the photoacoustic properties were exemplarily examined using phantom gels to assess their tomographic imaging capabilities. Finally, the robust luminescence in the visible range arising from the push-pull character of the peripheral moieties demonstrated a notable independence from aggregation and was exemplarily implemented for optical imaging (FLIM) through time-resolved multiphoton micro(spectro)scopy.
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Affiliation(s)
- Sidharth Thulaseedharan Nair Sailaja
- Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstraße 28/30, 48149 Münster, Germany
- CeNTech, CiMIC, SoN, Universität Münster, Heisenbergstraße 11, 48149 Münster, Germany
| | - Iván Maisuls
- Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstraße 28/30, 48149 Münster, Germany
- CeNTech, CiMIC, SoN, Universität Münster, Heisenbergstraße 11, 48149 Münster, Germany
| | - Alexander Hepp
- Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstraße 28/30, 48149 Münster, Germany
| | - Dana Brünink
- Institute for Solid State Theory and Center for Multiscale Theory and Computation, Universität Münster, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
| | - Nikos L Doltsinis
- Institute for Solid State Theory and Center for Multiscale Theory and Computation, Universität Münster, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany
| | - Andreas Faust
- European Institute for Molecular Imaging, Universität Münster, Röntgenstraße 16, 48149 Münster, Germany
- Department of Nuclear Medicine, University Hospital Münster, Albert-Schweitzer-Campus 1, 48149 Münster, Germany
| | - Sven Hermann
- European Institute for Molecular Imaging, Universität Münster, Röntgenstraße 16, 48149 Münster, Germany
- Department of Nuclear Medicine, University Hospital Münster, Albert-Schweitzer-Campus 1, 48149 Münster, Germany
| | - Cristian A Strassert
- Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstraße 28/30, 48149 Münster, Germany
- CeNTech, CiMIC, SoN, Universität Münster, Heisenbergstraße 11, 48149 Münster, Germany
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2
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Bezerra LF, Reis MP, Romo AI, Abreu DS, Gehlen MH, Longhinotti E, Paulo TF, Carvalho IM, Diógenes IC. Photophysical properties of push-π-pull type chromophores of aryl-substituted bipyridines in different solvents. J Photochem Photobiol A Chem 2022. [DOI: 10.1016/j.jphotochem.2021.113687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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3
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Burnstine‐Townley A, Mondal S, Agam Y, Nandi R, Amdursky N. Light‐Modulated Cationic and Anionic Transport across Protein Biopolymers**. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202111024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Alex Burnstine‐Townley
- Schulich Faculty of Chemistry Technion—Israel Institute of Technology Haifa 3200003 Israel
| | - Somen Mondal
- Schulich Faculty of Chemistry Technion—Israel Institute of Technology Haifa 3200003 Israel
| | - Yuval Agam
- Schulich Faculty of Chemistry Technion—Israel Institute of Technology Haifa 3200003 Israel
| | - Ramesh Nandi
- Schulich Faculty of Chemistry Technion—Israel Institute of Technology Haifa 3200003 Israel
| | - Nadav Amdursky
- Schulich Faculty of Chemistry Technion—Israel Institute of Technology Haifa 3200003 Israel
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Burnstine-Townley A, Mondal S, Agam Y, Nandi R, Amdursky N. Light-Modulated Cationic and Anionic Transport across Protein Biopolymers*. Angew Chem Int Ed Engl 2021; 60:24676-24685. [PMID: 34492153 DOI: 10.1002/anie.202111024] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Indexed: 12/13/2022]
Abstract
Light is a convenient source of energy and the heart of light-harvesting natural systems and devices. Here, we show light-modulation of both the chemical nature and ionic charge carrier concentration within a protein-based biopolymer that was covalently functionalized with photoacids or photobases. We explore the capability of the biopolymer-tethered photoacids and photobases to undergo excited-state proton transfer and capture, respectively. Electrical measurements show that both the photoacid- and photobase-functionalized biopolymers exhibit an impressive light-modulated increase in ionic conductivity. Whereas cationic protons are the charge carriers for the photoacid-functionalized biopolymer, water-derived anionic hydroxides are the suggested charge carriers for the photobase-functionalized biopolymer. Our work introduces a versatile toolbox to photomodulate both protons and hydroxides as charge carriers in polymers, which can be of interest for a variety of applications.
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Affiliation(s)
- Alex Burnstine-Townley
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa, 3200003, Israel
| | - Somen Mondal
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa, 3200003, Israel
| | - Yuval Agam
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa, 3200003, Israel
| | - Ramesh Nandi
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa, 3200003, Israel
| | - Nadav Amdursky
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa, 3200003, Israel
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5
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Makhal SC, Bhattacharyya A, Ghosh S, Guchhait N. Influence of acceptor strength on photoinduced charge transfer process in a newly designed molecule in bulk solvent and in β-CD microenvironment. J Photochem Photobiol A Chem 2018. [DOI: 10.1016/j.jphotochem.2018.07.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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6
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Kožurková M, Sabolová D, Kristian P. A review on acridinylthioureas and its derivatives: biological and cytotoxic activity. J Appl Toxicol 2017; 37:1132-1139. [PMID: 28370171 DOI: 10.1002/jat.3464] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 02/17/2017] [Accepted: 02/17/2017] [Indexed: 11/07/2022]
Abstract
Acridines possess two characteristics that have led many researchers to consider the agents interesting targets for future development as potential farmacophores: the planar acridine skeleton, which is able to intercalate into DNA, and the intense fluorescence of the agents. This review offers a study of the multifunctional character of acridines and the synthesis of novel acridine derivatives, with particular focus being placed on isothiocyanates and their congeners, e.g. thioureas, isothioureas, quaternary ammonium salts and platinum/gold conjugates. The review provides an overview of the structure, spectral properties, DNA binding and biological activity of acridinylthiourea congeners. These acridinylthiourea derivatives display significant cytotoxic activities against different types of cancer cell lines at micromolar concentrations. Copyright © 2017 John Wiley & Sons, Ltd.
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Affiliation(s)
- Mária Kožurková
- Department of Biochemisty, Institute of Chemistry, P.J. Šafárik University Košice, Moyzesova 11, Košice, Slovak Republic.,Biomedical Research Center, University Hospital Hradec Kralove, Sokolovska 581, Hradec Kralove, Czech Republic
| | - Danica Sabolová
- Department of Biochemisty, Institute of Chemistry, P.J. Šafárik University Košice, Moyzesova 11, Košice, Slovak Republic
| | - Pavol Kristian
- Department of Organic Chemistry, Institute of Chemistry, P.J. Šafárik University Košice, Moyzesova 11, Košice, Slovak Republic
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7
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Aydemir M, Haykır G, Türksoy F, Gümüş S, Dias FB, Monkman AP. Synthesis and investigation of intra-molecular charge transfer state properties of novel donor-acceptor-donor pyridine derivatives: the effects of temperature and environment on molecular configurations and the origin of delayed fluorescence. Phys Chem Chem Phys 2015; 17:25572-82. [PMID: 26372605 DOI: 10.1039/c5cp03937a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A novel series of donor-acceptor-donor (D-A-D) structured pyridine derivatives were synthesised and detailed photo-physical investigations were made using mainly steady-state and time-resolved spectroscopy techniques at varying temperatures. The investigations showed that the molecules have solvent polarity and temperature dependent excited-state configurations, confirmed in two different polarity solvents (295-90 K), i.e. methyl cyclohexane (MCH) and 2-methyltetrahdrofurane (2-MeTHF). In MCH, the investigations revealed dual fluorescence over the temperature range of 295-90 K. At 295 K, the ground-state configuration of the molecules has a partially twisted geometry as determined by DFT calculation, yet the emission originates totally from a locally excited (LE) state, however once the temperature is lowered to 90 K, the twisted molecular configuration is stabilised, and the emission originates from a fully-relaxed intramolecular charge transfer state (ICT), this is contrary to the systems where structural reorganisation stabilises ICT and this is frozen out at low temperatures. The DFT calculations revealed different ground state molecular configurations due to the presence of different electron-donating groups, e.g. the molecule including anthracene groups has a near 90° twisted geometry whereas the triphenylamine including molecule has a pyramidal geometrical folding, therefore, the decrease in temperature restricts the donor degree of rotational freedom. In 2-MeTHF solution, the fluorescence spectrum of both molecules is always of ICT character, but gradually red-shifts through the fluid to glass transition temperature (∼135 K), in this case, the fluorescence occurs after structural and solvent-shell relaxations, however, upon cooling below 135 K, the spectra dramatically shift back to blue giving rise to strong emission from an ICT excited-state (but not the LE state) where the molecules have unrelaxed geometries. This significant change in the nature of the emitting species was explained with specific solvent-solute dynamic interactions in the vicinity of the solvation shell and the effect of thermal excitation of molecular vibrational modes of the C-C bond linking donor and acceptor units. Finally, we confirmed that the molecules have ICT ground-state geometry in the solid-state phase (spin-coated films), and the time-resolved decay dynamics were investigated comparing the spin-coated films (at RT and 25 K) and MCH solutions (at 295 K and 90 K).
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Affiliation(s)
- Murat Aydemir
- Institute of Photonic Materials, University of Durham, South Road, DH1 5US, UK.
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8
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Chevreux S, Allain C, Wilbraham L, Nakatani K, Jacques P, Ciofini I, Lemercier G. Solvent tuned single molecule dual emission in protic solvents: effect of polarity and H-bonding. Faraday Discuss 2015; 185:285-97. [DOI: 10.1039/c5fd00054h] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Phen-PENMe2 has recently been proposed as a promising new molecule displaying solvent-tuned dual emission, highlighting an original and newly-described charge transfer model. The study of the photophysical behaviour of this molecule was extended to include protic solvents. The effects of polarity and hydrogen bonding lead to an even more evident dual emission associated with a large multi-emission band in some solvents like methanol, highlighting Phen-PENMe2 as a promising candidate for white light emission.
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Affiliation(s)
- S. Chevreux
- Reims Champagne-Ardenne University
- ICMR UMR CNRS no. 7312
- Reims Cedex 2
- France
| | - C. Allain
- PPSM
- CNRS UMR 8531
- Ecole Normale Supérieure de Cachan
- 94235 Cachan Cedex
- France
| | - L. Wilbraham
- PSL Research University
- Chimie ParisTech-CNRS UMR 8247
- Institut de Recherche de Chimie Paris
- Paris
- France
| | - K. Nakatani
- PPSM
- CNRS UMR 8531
- Ecole Normale Supérieure de Cachan
- 94235 Cachan Cedex
- France
| | - P. Jacques
- Université de Haute-Alsace
- UHA
- LPIM
- Mulhouse
- France
| | - I. Ciofini
- PSL Research University
- Chimie ParisTech-CNRS UMR 8247
- Institut de Recherche de Chimie Paris
- Paris
- France
| | - G. Lemercier
- Reims Champagne-Ardenne University
- ICMR UMR CNRS no. 7312
- Reims Cedex 2
- France
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9
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Chevreux S, Paulino Neto R, Allain C, Nakatani K, Jacques P, Ciofini I, Lemercier G. Solvent-tuned dual emission: a structural and electronic interplay highlighting a novel planar ICT (OPICT). Phys Chem Chem Phys 2015; 17:7639-42. [DOI: 10.1039/c4cp05661b] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Displaying a dual emission, a Phen-PENMe2 compound can be foreseen as a new model for fundamental studies.
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Affiliation(s)
- S. Chevreux
- Reims Champagne-Ardenne University
- ICMR UMR CNRS
- 51687 Reims cedex 2
- France
| | - R. Paulino Neto
- PSL Research University
- Chimie ParisTech – CNRS UMR 8247
- Institut de Recherche de Chimie Paris
- Paris
- France
| | - C. Allain
- PPSM
- CNRS UMR 8531
- Ecole Normale Supérieure de Cachan
- PPSM
- 94235 Cachan cedex
| | - K. Nakatani
- PPSM
- CNRS UMR 8531
- Ecole Normale Supérieure de Cachan
- PPSM
- 94235 Cachan cedex
| | - P. Jacques
- Université de Haute-Alsace
- UHA
- LPIM
- Mulhouse
- France
| | - I. Ciofini
- PSL Research University
- Chimie ParisTech – CNRS UMR 8247
- Institut de Recherche de Chimie Paris
- Paris
- France
| | - G. Lemercier
- Reims Champagne-Ardenne University
- ICMR UMR CNRS
- 51687 Reims cedex 2
- France
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10
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Behera SK, Karak A, Krishnamoorthy G. Photophysics of 2-(4'-amino-2'-hydroxyphenyl)-1H-imidazo-[4,5-c]pyridine and its analogues: intramolecular proton transfer versus intramolecular charge transfer. J Phys Chem B 2014; 119:2330-44. [PMID: 25337987 DOI: 10.1021/jp5064808] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Photophysical characteristics of 2-(4'-amino-2'-hydroxyphenyl)-1H-imidazo-[4,5-c]pyridine (AHPIP-c) have been studied in various aprotic and protic solvents using UV-visible, steady state fluorescence and time-resolved fluorescence spectroscopic techniques. To comprehend the competition between the intramolecular charge transfer (ICT) and the excited state intramolecular proton transfer (ESIPT) processes, the photophysical properties of 2-(4'-amino-2'-methoxyphenyl)-1H-imidazo-[4,5-c]pyridine (AMPIP-c) and 2-(4'-aminophenyl)-1H-imidazo-[4,5-c]pyridine (APIP-c) were also investigated. Though APIP-c displays twisted ICT (TICT) emission in protic solvents, AHPIP-c exhibits normal and tautomer emissions in aprotic as well as in protic solvents due to ESIPT. However, the methoxy derivative, AMPIP-c, emits weak TICT fluorescence in methanol.
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Affiliation(s)
- Santosh Kumar Behera
- Department of Chemistry, Indian Institute of Technology Guwahati , Guwahati 781039, India
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11
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Gao J, Chen W, Dou L, Chen CC, Chang WH, Liu Y, Li G, Yang Y. Elucidating double aggregation mechanisms in the morphology optimization of diketopyrrolopyrrole-based narrow bandgap polymer solar cells. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2014; 26:3142-3147. [PMID: 24520006 DOI: 10.1002/adma.201305645] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Revised: 12/20/2013] [Indexed: 06/03/2023]
Abstract
The power conversion efficiency (PCE) of a DPP-based polymer solar cell is significantly improved by using DIO or DCB as processing additives. The discovery that DCB outperforms DIO with a significantly wider solvent mixture operation window suggests different optimization mechanisms. Although both solvent mixture systems involve double aggregation processes, including a similar solution-to-film aggregation, however, two distinct solution-stage aggregations are observed: relatively amorphous polymer aggregates form in the CF-DIO solution, while more crystalline polymer aggregates form in CF-DCB solution.
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Affiliation(s)
- Jing Gao
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
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12
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Elucidation of Selectivity for Uranyl Ions with an ICT Organosilane-Modified Fluorescent Receptor. J Fluoresc 2014; 24:727-33. [DOI: 10.1007/s10895-013-1345-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Accepted: 12/27/2013] [Indexed: 01/28/2023]
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13
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Lauer MH, Drekener RL, Correia CRD, Gehlen MH. Fluorescence from bisaryl-substituted maleimide derivatives. Photochem Photobiol Sci 2014; 13:859-66. [DOI: 10.1039/c4pp00001c] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A series of bisaryl-substituted fluorescent maleimides was synthesized via the Heck arylation.
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Affiliation(s)
- Milena Helmer Lauer
- Institute of Chemistry of São Carlos
- University of São Paulo
- São Carlos, Brazil
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14
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Chipem FAS, Mishra A, Krishnamoorthy G. The role of hydrogen bonding in excited state intramolecular charge transfer. Phys Chem Chem Phys 2012; 14:8775-90. [DOI: 10.1039/c2cp23879a] [Citation(s) in RCA: 142] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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15
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Simas ER, Gehlen MH, Pinto MFS, Siqueira J, Misoguti L. Intrachain Energy Migration to Weak Charge-Transfer State in Polyfluorene End-Capped with Naphthalimide Derivative. J Phys Chem A 2010; 114:12384-90. [DOI: 10.1021/jp108168f] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Emanuelle R Simas
- Instituto de Química de São Carlos, Universidade de São Paulo, 13560-590, São Carlos-SP, Brasil
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16
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Samsonova LG, Selivanov NI, Kopylova TN, Artyukhov VY, Maier GV, Plotnikov VG, Sazhnikov VA, Khlebunov AA, Alfimov MV. Experimental and theoretical investigation of the spectral and luminescent properties of some acridine compounds. HIGH ENERGY CHEMISTRY 2009. [DOI: 10.1134/s0018143909020076] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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17
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Luminous, fully aliphatic polyamides: Multicolor photoluminescence, their pH and solvent dependency. Eur Polym J 2008. [DOI: 10.1016/j.eurpolymj.2008.01.036] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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18
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Sabatini CA, Pereira RV, Gehlen MH. Fluorescence Modulation of Acridine and Coumarin Dyes by Silver Nanoparticles. J Fluoresc 2007; 17:377-82. [PMID: 17549612 DOI: 10.1007/s10895-007-0204-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2007] [Accepted: 05/04/2007] [Indexed: 10/23/2022]
Abstract
Silver nanoparticles were synthesized by chemical reduction of silver ions by sodium borohydride in the presence of poly-(N)-vinyl-2-pyrrolidone in solution of short chain alcohols. The nanoparticles are stable in 2-propanol, and the average diameter of the Ag colloid obtained in this solvent is about 6 nm. The photophysical properties of acridinium and coumarin dyes in 2-propanol are affected by the presence of silver nanoparticles. The interaction of silver nanoparticles with acridinium derivative leads to a spectral change of its intramolecular charge transfer (ICT) absorption band. The dye emission increases suddenly with the initial addition of the Ag metal nanoparticles, but at a high concentration of the colloid, static fluorescence quenching occurs with a progressive decrease of the fluorescence efficiency. Amino coumarin fluorescence is only quenched by the silver nanoparticles in solution.
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Affiliation(s)
- Carolina A Sabatini
- Instituto de Química de São Carlos, Universidade de São Paulo, 13566-590, São Carlos, SP, Brazil
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Pereira RV, Gehlen MH. Polymerization and Conformational Transition of Poly(methacrylic Acid) Probed by Electronic Spectroscopy of Aminoacridines. Macromolecules 2007. [DOI: 10.1021/ma062020c] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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20
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Pereira RV, Gehlen MH. H-bonding assisted intramolecular charge transfer in 1-aminopyrene derivatives. Chem Phys Lett 2006. [DOI: 10.1016/j.cplett.2006.05.109] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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21
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Pereira RV, Gehlen MH. Photoinduced Intramolecular Charge Transfer in 9-Aminoacridinium Derivatives Assisted by Intramolecular H-Bond. J Phys Chem A 2006; 110:7539-46. [PMID: 16774194 DOI: 10.1021/jp0561470] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Fluorochromic dyes derived from 9-aminoacridinium containing a vinylene function with electron withdrawing groups such as diethyl [(acridinium-9-ylamino)methylene]malonate (I), ethyl [(acridinium-9-ylamino)methylene]cyanoacetate (II), [(acridinium-9-ylamino)methylene]malononitrile (III), are prepared and studied in their monoprotonated form. Absorption spectra of the new dyes are red shifted compared to that of the precursor dye. The observed dual fluorescence and multiexponential decay are ascribed to normal emission from the acridinium chromophore in addition to excited-state intramolecular charge transfer (ESICT) process. However, biexponential decay character is observed only for the dicyano derivative (compound III), whereas for the two other systems, more complex kinetics and a three-component decay is recovered. The analysis of the fluorescence decays in different solvents for the first two compounds reveals two short-lived components in the range of 160-350 ps and 1.1-3.0 ns, related to formation and decay of the ESICT state, plus a third one with decay time of about 9 ns, which is ascribed to the normal emission from the acridinium chromophore as an enol tautomer or as an intramolecular H-bond conformer (closed form tautomer). For the dicyano derivative, in which the absence of carbonyl group precludes the H-bond interaction, the biexponential fitting reveals a slightly fast formation rate of the ESICT state with values on the order of 10(10) s(-1), whereas its decay time is between 0.6 and 3.2 ns, depending on the solvent used.
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Affiliation(s)
- Robson Valentim Pereira
- Instituto de Química de São Carlos, Universidade de São Paulo, 13566-590, São Carlos-SP, Brazil
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Photophysical properties of trans-3-(4-monomethylamino-phenyl)-acrylonitrile: Evidence of twisted intramolecular charge transfer (TICT) process. Chem Phys 2006. [DOI: 10.1016/j.chemphys.2005.12.032] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Pereira RV, Gehlen MH. Spectroscopy of Auramine Fluorescent Probes Free and Bound to Poly(Methacrylic Acid). J Phys Chem B 2006; 110:6537-42. [PMID: 16570951 DOI: 10.1021/jp054833t] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Auramines containing a vinyl group with strong electron-withdrawing substituent exhibit a pi-conjugated extended effect that gives a red shift in their absorption and emission bands. The new fluorochromic dyes were bound to poly(methacrylic acid) (PMA), and their photophysical dynamics in methanol and in aqueous solution were studied. These derivatives were also used as optical probes for copolymerization process. The process was monitored by the changes in electronic absorption with a concomitant fading of the free vinyl auramine absorption band in the red and an appearance of a UV band ascribed to dye bound to the polymer chain. The conformational transition of PMA with solvent and pH was clearly observed by the drastic changes in the photophysical properties of these auramine derivatives attached to the polymer chain. Time-resolved experiments revealed an unusual long-lived decay component of about 2.2-2.6 ns in aqueous solution at low pH together with two picosecond components (50 and 570 ps). Such long decay was only reported in the literature for auramine adsorbed in solid matrices. It was ascribed to the fraction of bound auramine in a region of compact coil of PMA.
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Affiliation(s)
- Robson Valentim Pereira
- Instituto de Química de São Carlos, Universidade de São Paulo, 13560-590, São Carlos, SP, Brazil
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