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Kumar M, Talakkal AK, Mohapatra RK, Ansari A. Photophysical properties of four-membered BN 3 heterocyclic compounds: theoretical insights. J Mol Model 2023; 29:336. [PMID: 37828393 DOI: 10.1007/s00894-023-05731-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 09/20/2023] [Indexed: 10/14/2023]
Abstract
CONTEXT Understanding the photochemistry of boron nitrogen (BN)-containing compounds is an important aspect to enhance the various optical and electronic applications. In this work, we have explored the structure, bonding, reactivity, electronic absorption (UV-Vis), and light harvesting efficiency (LHE) of a series of BN3 ring and open-chain systems. The frontier molecular orbitals (FMO) analysis found that ring systems have a low HOMO-LUMO energy gap as compared to the open-chain systems which insinuates the feasibility of ring systems in the optoelectronic materials. Also, the molecular electrostatic potential (MEP) maps have been computed to pursue the electrophilic and nucleophilic sites available at the surface of the compound. Interestingly, we have found that the open-chain compounds show more molecular charge distribution range rather than the ring compounds. The investigation of photophysical properties showed that the UV-Vis absorption significantly red-shifted in BN3 ring systems as compared to open-chain counterparts. Furthermore, light harvesting efficiency (LHE) was also found higher in the ring systems as compared to the BN3 open-chain systems. Moreover, the computed structural parameters are found well corroborated with the available X-ray data. METHODS Structures of all compounds were optimized by using density functional theory (DFT) method, with M06-2X/6-31G(d,p) level. All the calculations in this work are carried out in Gaussian 16 program package. GaussView6.1 software was used for the modeling of initial geometries and for the plotting of MEP plots. To account the solvent effect on geometries the polarized continuum model (PCM) was used and tetrahydrofuran (THF) taken as solvent. The NBO6.0 program (incorporated in G16 software) was used for the exploration of bonding nature and stabilization energies of B-N bond. The absorption spectra were simulated by using ORCA 4.2 program.
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Affiliation(s)
- Manjeet Kumar
- Department of Chemistry, Central University of Haryana, Mahendergarh, 123031, India
| | | | - Ranjan K Mohapatra
- Department of Chemistry, Government College of Engineering, Keonjhar, Odisha, 758002, India
| | - Azaj Ansari
- Department of Chemistry, Central University of Haryana, Mahendergarh, 123031, India.
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Suleymanov AA, Scopelliti R, Severin K. Synthesis of Four-Membered BN 3 Heterocycles by the Borylation of Triazenes. Inorg Chem 2022; 61:1546-1551. [PMID: 34986634 DOI: 10.1021/acs.inorgchem.1c03309] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Borylated triazenes were synthesized by the dehydrocoupling of triazenes with 9-borabicyclo(3.3.1)nonane, by the condensation of triazenes with BEt3, or by the reaction of sodium triazenides with dialkyl- or diarylboron halides. The structures of the products were found to depend on the size of the substituents. Sterically demanding mesityl groups at boron or nitrogen gave rise to open-chain structures, whereas smaller substituents led to the formation of novel BN3 heterocycles.
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Affiliation(s)
- Abdusalom A Suleymanov
- Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Rosario Scopelliti
- Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Kay Severin
- Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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3
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Singh AK, Nair AV, Singh NDP. Small Two-Photon Organic Fluorogenic Probes: Sensing and Bioimaging of Cancer Relevant Biomarkers. Anal Chem 2021; 94:177-192. [PMID: 34793114 DOI: 10.1021/acs.analchem.1c04306] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Amit Kumar Singh
- Department of Chemistry, Indian Institute of Technology Kharagpur 721302, West Bengal, India
| | - Asha V Nair
- Department of Chemistry, Indian Institute of Technology Kharagpur 721302, West Bengal, India
| | - N D Pradeep Singh
- Department of Chemistry, Indian Institute of Technology Kharagpur 721302, West Bengal, India
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Abstract
Boron and tin complexes have been a versatile and very interesting scaffold for the design of nonlinear optical (NLO) chromophores. In this paper we present a wide range of reports since the 1990s to date, which include second-order (e.g., second harmonic generation) and third-order (e.g., two-photon absorption) NLO properties. After a short introduction on the origin of the NLO response in molecules, the different features associated with the introduction of these inorganic motifs in the organic-based NLO materials are discussed: Their effect on the accepting/donating capabilities of the substituents, on the efficiency of the π-conjugated linkage, and on the topology of the chromophores which can be tuned from the first generation of “push-pull” chromophores to more sophisticated two- or three-dimensional architectures.
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Hecht R, Kade J, Schmidt D, Nowak-Król A. n-Channel Organic Semiconductors Derived from Air-Stable Four-Coordinate Boron Complexes of Substituted Thienylthiazoles. Chemistry 2017; 23:11620-11628. [DOI: 10.1002/chem.201701922] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Indexed: 02/04/2023]
Affiliation(s)
- Reinhard Hecht
- Center for Nanosystems Chemistry (CNC) and Bavarian Polymer Institute (BPI); Universität Würzburg; Theodor-Boveri-Weg 97074 Würzburg Germany
- Institut für Organische Chemie; Universität Würzburg; Am Hubland 97074 Würzburg Germany
| | - Juliane Kade
- Institut für Organische Chemie; Universität Würzburg; Am Hubland 97074 Würzburg Germany
| | - David Schmidt
- Center for Nanosystems Chemistry (CNC) and Bavarian Polymer Institute (BPI); Universität Würzburg; Theodor-Boveri-Weg 97074 Würzburg Germany
- Institut für Organische Chemie; Universität Würzburg; Am Hubland 97074 Würzburg Germany
| | - Agnieszka Nowak-Król
- Center for Nanosystems Chemistry (CNC) and Bavarian Polymer Institute (BPI); Universität Würzburg; Theodor-Boveri-Weg 97074 Würzburg Germany
- Institut für Organische Chemie; Universität Würzburg; Am Hubland 97074 Würzburg Germany
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Lanoë PH, Mettra B, Liao YY, Calin N, D'Aléo A, Namikawa T, Kamada K, Fages F, Monnereau C, Andraud C. Theoretical and Experimental Study on Boron β-Diketonate Complexes with Intense Two-Photon-Induced Fluorescence in Solution and in the Solid State. Chemphyschem 2016; 17:2128-36. [DOI: 10.1002/cphc.201600178] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Indexed: 02/06/2023]
Affiliation(s)
- Pierre-Henri Lanoë
- Laboratoire de Chimie UMR CNRS 5182; Ecole Normale Supérieure de Lyon/Université de Lyon, 46; Allée d'Italie, 69007 Lyon France
| | - Bastien Mettra
- Laboratoire de Chimie UMR CNRS 5182; Ecole Normale Supérieure de Lyon/Université de Lyon, 46; Allée d'Italie, 69007 Lyon France
| | - Yuan Yuan Liao
- Laboratoire de Chimie UMR CNRS 5182; Ecole Normale Supérieure de Lyon/Université de Lyon, 46; Allée d'Italie, 69007 Lyon France
| | - Nathalie Calin
- Laboratoire de Chimie UMR CNRS 5182; Ecole Normale Supérieure de Lyon/Université de Lyon, 46; Allée d'Italie, 69007 Lyon France
| | - Anthony D'Aléo
- CINAM UMR CNRS 7325; Université Aix-Marseille; Campus de Luminy, Case 913, 13288 Marseille France
| | - Tomotaka Namikawa
- IFMRI; National Institute of Advanced Industrial Science and Technology (AIST), Ikeda; Osaka 563-8577 Japan
| | - Kenji Kamada
- IFMRI; National Institute of Advanced Industrial Science and Technology (AIST), Ikeda; Osaka 563-8577 Japan
| | - Fréderic Fages
- CINAM UMR CNRS 7325; Université Aix-Marseille; Campus de Luminy, Case 913, 13288 Marseille France
| | - Cyrille Monnereau
- Laboratoire de Chimie UMR CNRS 5182; Ecole Normale Supérieure de Lyon/Université de Lyon, 46; Allée d'Italie, 69007 Lyon France
| | - Chantal Andraud
- Laboratoire de Chimie UMR CNRS 5182; Ecole Normale Supérieure de Lyon/Université de Lyon, 46; Allée d'Italie, 69007 Lyon France
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He G, Shynkaruk O, Lui MW, Rivard E. Small Inorganic Rings in the 21st Century: From Fleeting Intermediates to Novel Isolable Entities. Chem Rev 2014; 114:7815-80. [DOI: 10.1021/cr400547x] [Citation(s) in RCA: 156] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Gang He
- Department of Chemistry, University of Alberta, 11227 Saskatchewan
Drive, Edmonton, Alberta, Canada T6G 2G2
| | - Olena Shynkaruk
- Department of Chemistry, University of Alberta, 11227 Saskatchewan
Drive, Edmonton, Alberta, Canada T6G 2G2
| | - Melanie W. Lui
- Department of Chemistry, University of Alberta, 11227 Saskatchewan
Drive, Edmonton, Alberta, Canada T6G 2G2
| | - Eric Rivard
- Department of Chemistry, University of Alberta, 11227 Saskatchewan
Drive, Edmonton, Alberta, Canada T6G 2G2
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Kim D, Ryu HG, Ahn KH. Recent development of two-photon fluorescent probes for bioimaging. Org Biomol Chem 2014; 12:4550-66. [DOI: 10.1039/c4ob00431k] [Citation(s) in RCA: 160] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Fluorescent probes are essential tools for studying biological systems.
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Affiliation(s)
- Dokyoung Kim
- Department of Chemistry and Center for Electro-Photo Behaviors in Advanced Molecular Systems
- Gyungbuk, Korea 790-784
| | - Hye Gun Ryu
- Department of Chemistry and Center for Electro-Photo Behaviors in Advanced Molecular Systems
- Gyungbuk, Korea 790-784
| | - Kyo Han Ahn
- Department of Chemistry and Center for Electro-Photo Behaviors in Advanced Molecular Systems
- Gyungbuk, Korea 790-784
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Misra R, Jadhav T, Mobin SM. Ferrocenyl pyrazaboles: design, synthesis, structure, and properties. Dalton Trans 2014; 43:2013-22. [PMID: 24270929 DOI: 10.1039/c3dt52315b] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Rajneesh Misra
- Department of Chemistry, Indian Institute of Technology Indore, Indore 452 017, India.
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Breunig JM, Hübner A, Bolte M, Wagner M, Lerner HW. Reactivity of Phosphaboradibenzofulvene toward Hydrogen, Acetonitrile, Benzophenone, and 2,3-Dimethylbutadiene. Organometallics 2013. [DOI: 10.1021/om400553j] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jens Michael Breunig
- Institut
für Anorganische Chemie, Goethe-Universität Frankfurt am Main, Max-von-Laue-Straße
7, 60438 Frankfurt am Main, Germany
| | - Alexander Hübner
- Institut
für Anorganische Chemie, Goethe-Universität Frankfurt am Main, Max-von-Laue-Straße
7, 60438 Frankfurt am Main, Germany
| | - Michael Bolte
- Institut
für Anorganische Chemie, Goethe-Universität Frankfurt am Main, Max-von-Laue-Straße
7, 60438 Frankfurt am Main, Germany
| | - Matthias Wagner
- Institut
für Anorganische Chemie, Goethe-Universität Frankfurt am Main, Max-von-Laue-Straße
7, 60438 Frankfurt am Main, Germany
| | - Hans-Wolfram Lerner
- Institut
für Anorganische Chemie, Goethe-Universität Frankfurt am Main, Max-von-Laue-Straße
7, 60438 Frankfurt am Main, Germany
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Misra R, Jadhav T, Mobin SM. Aryl pyrazaboles: a new class of tunable and highly fluorescent materials. Dalton Trans 2013; 42:16614-20. [PMID: 24071967 DOI: 10.1039/c3dt52154k] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Rajneesh Misra
- Department of Chemistry, Indian Institute of Technology Indore, Indore 452 017, India.
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12
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Jadhav T, Maragani R, Misra R, Sreeramulu V, Rao DN, Mobin SM. Design and synthesis of donor–acceptor pyrazabole derivatives for multiphoton absorption. Dalton Trans 2013; 42:4340-2. [DOI: 10.1039/c3dt33065f] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Nicoud JF, Bolze F, Sun XH, Hayek A, Baldeck P. Boron-Containing Two-Photon-Absorbing Chromophores. 3. One- and Two-Photon Photophysical Properties of p-Carborane-Containing Fluorescent Bioprobes. Inorg Chem 2011; 50:4272-8. [DOI: 10.1021/ic102043v] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jean-François Nicoud
- Laboratoire de Biophotonique et Pharmacologie, Université de Strasbourg, CNRS (UMR 7213), Faculté de Pharmacie, 74 route du Rhin, F-67401 Illkirch Graffenstaden Cedex, France
| | - Frédéric Bolze
- Laboratoire de Biophotonique et Pharmacologie, Université de Strasbourg, CNRS (UMR 7213), Faculté de Pharmacie, 74 route du Rhin, F-67401 Illkirch Graffenstaden Cedex, France
| | - Xiao-Hua Sun
- Laboratoire de Biophotonique et Pharmacologie, Université de Strasbourg, CNRS (UMR 7213), Faculté de Pharmacie, 74 route du Rhin, F-67401 Illkirch Graffenstaden Cedex, France
| | - Ali Hayek
- Laboratoire de Biophotonique et Pharmacologie, Université de Strasbourg, CNRS (UMR 7213), Faculté de Pharmacie, 74 route du Rhin, F-67401 Illkirch Graffenstaden Cedex, France
| | - Patrice Baldeck
- Laboratoire de Spectrométrie Physique, Université Joseph Fourier, CNRS (UMR 5588), BP 87, F-38402 Saint Martin d’Hères, France
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Sakuda E, Ando Y, Ito A, Kitamura N. Extremely Large Dipole Moment in the Excited Singlet State of Tris{[p-(N,N-dimethylamino)phenylethynyl]duryl}borane. J Phys Chem A 2010; 114:9144-50. [DOI: 10.1021/jp1057463] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Eri Sakuda
- Department of Chemistry, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Yuki Ando
- Department of Chemistry, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Akitaka Ito
- Department of Chemistry, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Noboru Kitamura
- Department of Chemistry, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan
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Kobayashi K, Kita Y, Shigeiwa M, Imamura S, Maeda S. Synthesis and Optical Properties, Including Two-Photon Absorption Cross-Sections, of Differentially Functionalized Starburst-Type π-Conjugated Molecules. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2009. [DOI: 10.1246/bcsj.82.1416] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Flaherty DP, Dong Y, Vennerstrom JL. A one-pot synthesis of unsymmetrical bis-styrylbenzenes. Tetrahedron Lett 2009. [DOI: 10.1016/j.tetlet.2009.08.083] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Kitamura N, Sakuda E, Ando Y. Spectroscopic and Excited-state Properties of Triarylboranes and Their Transition-metal Complexes. CHEM LETT 2009. [DOI: 10.1246/cl.2009.938] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Hayek A, Bolze F, Bourgogne C, Baldeck PL, Didier P, Arntz Y, Mély Y, Nicoud JF. Boron Containing Two-Photon Absorbing Chromophores. 2. Fine Tuning of the One- and Two-Photon Photophysical Properties of Pyrazabole Based Fluorescent Bioprobes. Inorg Chem 2009; 48:9112-9. [DOI: 10.1021/ic900627g] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ali Hayek
- Laboratoire de Biophotonique et Pharmacologie, Université de Strasbourg (UMR CNRS 7213), Faculté de Pharmacie, 74 route du Rhin, 67401 Illkirch, France
| | - Frédéric Bolze
- Laboratoire de Biophotonique et Pharmacologie, Université de Strasbourg (UMR CNRS 7213), Faculté de Pharmacie, 74 route du Rhin, 67401 Illkirch, France
| | - Cyril Bourgogne
- Institut de Physique et Chimie des Matériaux de Strasbourg, Université de Strasbourg (UMR CNRS 7504), 23 rue du Loess, 67034 Strasbourg cedex 2, France
| | - Patrice L. Baldeck
- Laboratoire de Spectrométrie Physique, Université Joseph Fourier (UMR CNRS 5588), BP 87, 38402 Saint-Martin d’Hères, France
| | - Pascal Didier
- Laboratoire de Biophotonique et Pharmacologie, Université de Strasbourg (UMR CNRS 7213), Faculté de Pharmacie, 74 route du Rhin, 67401 Illkirch, France
| | - Youri Arntz
- Laboratoire de Biophotonique et Pharmacologie, Université de Strasbourg (UMR CNRS 7213), Faculté de Pharmacie, 74 route du Rhin, 67401 Illkirch, France
| | - Yves Mély
- Laboratoire de Biophotonique et Pharmacologie, Université de Strasbourg (UMR CNRS 7213), Faculté de Pharmacie, 74 route du Rhin, 67401 Illkirch, France
| | - Jean-François Nicoud
- Laboratoire de Biophotonique et Pharmacologie, Université de Strasbourg (UMR CNRS 7213), Faculté de Pharmacie, 74 route du Rhin, 67401 Illkirch, France
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Jacquart A, Tauc P, Nakatani K, Ishow E. Formation of fluorescence reliefs photocontrolled by collective mass migration. ACTA ACUST UNITED AC 2009. [DOI: 10.1039/b916454e] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Andraud C, Fortrie R, Barsu C, Stéphan O, Chermette H, Baldeck PL. Excitonically Coupled Oligomers and Dendrimers for Two-Photon Absorption. PHOTORESPONSIVE POLYMERS II 2008. [DOI: 10.1007/12_2008_158] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Lemaur V, Cornil J, Didier D, Mujawase A, Sergeyev S. A Joint Theoretical and Experimental Insight into the Electronic Structure of Chromophores Derived from 6H,12H-5,11-Methanodibenzo[b,f][1,5]diazocine. Helv Chim Acta 2007. [DOI: 10.1002/hlca.200790216] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Finikova OS, Troxler T, Senes A, DeGrado WF, Hochstrasser RM, Vinogradov SA. Energy and electron transfer in enhanced two-photon-absorbing systems with triplet cores. J Phys Chem A 2007; 111:6977-90. [PMID: 17608457 PMCID: PMC2441487 DOI: 10.1021/jp071586f] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Enhanced two-photon-absorbing (2PA) systems with triplet cores are currently under scrutiny for several biomedical applications, including photodynamic therapy (PDT) and two-photon microscopy of oxygen. The performance of so far developed molecules, however, is substantially below expected. In this study we take a detailed look at the processes occurring in these systems and propose ways to improve their performance. We focus on the interchromophore distance tuning as a means for optimization of two-photon sensors for oxygen. In these constructs, energy transfer from several 2PA chromophores is used to enhance the effective 2PA cross section of phosphorescent metalloporphyrins. Previous studies have indicated that intramolecular electron transfer (ET) can act as an effective quencher of phosphorescence, decreasing the overall sensor efficiency. We studied the interplay between 2PA, energy transfer, electron transfer, and phosphorescence emission using Rhodamine B-Pt tetrabenzoporphyrin (RhB-PtTBP) adducts as model compounds. 2PA cross sections (sigma2) of tetrabenzoporphyrins (TBPs) are in the range of several tens of GM units (near 800 nm), making TBPs superior 2PA chromophores compared to regular porphyrins (sigma2 values typically 1-2 GM). Relatively large 2PA cross sections of rhodamines (about 200 GM in 800-850 nm range) and their high photostabilities make them good candidates as 2PA antennae. Fluorescence of Rhodamine B (lambda(fl) = 590 nm, phi(fl) = 0.5 in EtOH) overlaps with the Q-band of phosphorescent PtTBP (lambda(abs) = 615 nm, epsilon = 98 000 M(-1) cm(-1), phi(p) approximately 0.1), suggesting that a significant amplification of the 2PA-induced phosphorescence via fluorescence resonance energy transfer (FRET) might occur. However, most of the excitation energy in RhB-PtTBP assemblies is consumed in several intramolecular ET processes. By installing rigid nonconducting decaproline spacers (Pro10) between RhB and PtTBP, the intramolecular ETs were suppressed, while the chromophores were kept within the Förster r0 distance in order to maintain high FRET efficiency. The resulting assemblies exhibit linear amplification of their 2PA-induced phosphorescence upon increase in the number of 2PA antenna chromophores and show high oxygen sensitivity. We also have found that PtTBPs possess unexpectedly strong forbidden S0 --> T1 bands (lambda(max) = 762 nm, epsilon = 120 M-1 cm-1). The latter may overlap with the laser spectrum and lead to unwanted linear excitation.
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Affiliation(s)
- Olga S Finikova
- Departments of Biochemistry and Biophysics and Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA
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