1
|
Szemik-Hojniak A, Deperasińska I, Erez Y, Gawłowska M, Jerzykiewicz L. Ultrafast excited state dynamics of pyridine N-oxide derivative in solution; femtosecond fluorescence up-conversion and theoretical calculations. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2023; 285:121896. [PMID: 36183536 DOI: 10.1016/j.saa.2022.121896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 08/29/2022] [Accepted: 09/13/2022] [Indexed: 06/16/2023]
Abstract
In this study we have investigated 2-ethylamino-4-nitro-6-methyl pyridine N-oxide (2E6M) molecule that belongs to important group of Proton Coupled Electron Transfer (PCET) compounds where both the charge transfer (CT) and proton transfer processes in excited states may proceed. In this case, this is possible due to the donors and acceptors of electrons and protons in this system, as well as due to the presence of intramolecular {N-H… O [2,566(3) Å}, hydrogen bond.Using stationary and time-resolved spectroscopy, as well as quantum chemical calculations on the DFT and TD DFT B3LYP/6-31G (d,p) level of theory, a partial CT nature of the S0 → S1 transition in both tautomeric forms (N and T) has been revealed. Additionally, the excited state intramolecular proton transfer (ESIPT) process shown to be more favorable in apolar and weakly polar solvents than in strongly polar acetonitrile (EN(S1) > ET(S1). The displacement of charge from the amine group and the ring to the nitro group has been observed on the changing shapes of the HOMO and LUMO orbitals involved in this transition what further quantitatively allowed to realize the increase in the dipole moment of both forms in the electronic excited state. The calculations show that in two solvents with radically different polarity (heptane, acetonitrile), dipole moments of both forms are very similar [in acetonitrile uN(S1) and uT(S1) are 11.0 D and 11.5 D, respectively]. Hence, in polar media both forms can be stabilized in a comparable manner. This made it difficult for us to assign a single fluorescent band in acetonitrile to one of the tautomeric forms. However, it seems that due to application of time-resolved spectroscopy, this problem has been clarified. The TCSPC decay curve in acetonitrile with an ultrafast lifetime assigned to the (N) form, along with the femtosecond up-conversion signals that demonstrated only an ultrafast decay without any rise-time of a new excited (T) species, allowed us to conclude that in 2E6M in strongly polar solvent the ESIPT does not occur.The unique fluorescence band origins from the (N) form. In protic solvents, the significant kinetic isotopic effects have provided us with conclusive evidence for the presence of the solvent-assisted ESIPT process. Furthermore, it was noticed that the fluorescence lifetime in D2O (100-120 fs) estimated from the up-conversion signals is about 40 times shorter relative to methanol. This may suggest that the sine qua non for the ESIPT process in 2E6M in protic solvents is the formation of a complex with a solvent molecule in the hydrogen bridge between the proton donor and proton acceptor, respectively.
Collapse
Affiliation(s)
- Anna Szemik-Hojniak
- Faculty of Chemistry, University of Wroclaw, Joliot-Curie 14 st, 50-383 Wrocław, Poland; The Angelus Silesius State University of Applied Sciences, Institute of Health, Zamkowa 4 str 58-300 Wałbrzych, Poland.
| | - Irena Deperasińska
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46,02-668 Warsaw, Poland
| | - Yuval Erez
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University, Tel Aviv 69978, Israel
| | - Monika Gawłowska
- The Angelus Silesius State University of Applied Sciences, Institute of Health, Zamkowa 4 str 58-300 Wałbrzych, Poland
| | - L Jerzykiewicz
- Faculty of Chemistry, University of Wroclaw, Joliot-Curie 14 st, 50-383 Wrocław, Poland
| |
Collapse
|
2
|
Hurley JJM, Zhu L. Excitation Energy-Dependent, Excited-State Intramolecular Proton Transfer-Based Dual Emission in Poor Hydrogen-Bonding Solvents. J Phys Chem A 2022; 126:5711-5720. [PMID: 35980823 DOI: 10.1021/acs.jpca.2c03668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
2-(2'-Hydroxyphenyl)benzoxazole (HBO) substituted at the 5'-position with bipyridylvinylene phenylenevinylene (compound 2) produces both normal and, via an excited-state intramolecular proton transfer (ESIPT) reaction, tautomer emissions in solvents that preserve intramolecular hydrogen bonds. The abundance of the tautomer emission from compound 2 in a poor hydrogen-bonding solvent increases in response to the application of a higher excitation energy. Based on quantum chemical calculations, the excitation-dependent dual emission is consistent with a model in which the ESIPT reaction is more favored in the S2 than in the S1 electronically excited state.
Collapse
Affiliation(s)
- Joseph J M Hurley
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, Tallahassee, Florida 32306-4390, United States
| | - Lei Zhu
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, Tallahassee, Florida 32306-4390, United States
| |
Collapse
|
3
|
Tasior M, Deperasińska I, Morawska K, Banasiewicz M, Vakuliuk O, Kozankiewicz B, Gryko DT. Vertically π-expanded coumarin – synthesis via the Scholl reaction and photophysical properties. Phys Chem Chem Phys 2014; 16:18268-75. [DOI: 10.1039/c4cp02003k] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
A short and efficient access to a unique type of π-expanded coumarin is achieved.
Collapse
Affiliation(s)
- Mariusz Tasior
- Institute of Organic Chemistry
- Polish Academy of Sciences
- Warsaw, Poland
| | | | | | | | - Olena Vakuliuk
- Institute of Organic Chemistry
- Polish Academy of Sciences
- Warsaw, Poland
- Faculty of Chemistry
- Warsaw University of Technology
| | | | - Daniel T. Gryko
- Institute of Organic Chemistry
- Polish Academy of Sciences
- Warsaw, Poland
- Faculty of Chemistry
- Warsaw University of Technology
| |
Collapse
|
4
|
Szemik-Hojniak A, Wiśniewski Ł, Deperasińska I, Makarewicz A, Jerzykiewicz L, Puszko A, Erez Y, Huppert D. The impact of solvent polarity on intramolecular proton and electron transfer in 2-alkylamino-4-nitro-5-methyl pyridine N-oxides. Phys Chem Chem Phys 2012; 14:8147-59. [DOI: 10.1039/c2cp40591a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
5
|
Klerk JD, van Stokkum IHM, Szemik-Hojniak A, Deperasińska I, Gooijer C, Zhang H, Buma WJ, Ariese F. Excited State Processes of 2-Butylamino-6-methyl-4-nitropyridine N-oxide in Nonpolar Solvents. A Transient Absorption Spectroscopy Study. J Phys Chem A 2010; 114:4045-50. [DOI: 10.1021/jp909468h] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Joost de Klerk
- Laser Centre Vrije Universiteit Amsterdam, The Netherlands, Department of Chemistry, University of Wroclaw, Poland, Institute of Physics, Polish Academy of Sciences, Warsaw, Poland, and Van’t Hoff Institute for Molecular Sciences, University of Amsterdam, The Netherlands
| | - Ivo H. M. van Stokkum
- Laser Centre Vrije Universiteit Amsterdam, The Netherlands, Department of Chemistry, University of Wroclaw, Poland, Institute of Physics, Polish Academy of Sciences, Warsaw, Poland, and Van’t Hoff Institute for Molecular Sciences, University of Amsterdam, The Netherlands
| | - Anna Szemik-Hojniak
- Laser Centre Vrije Universiteit Amsterdam, The Netherlands, Department of Chemistry, University of Wroclaw, Poland, Institute of Physics, Polish Academy of Sciences, Warsaw, Poland, and Van’t Hoff Institute for Molecular Sciences, University of Amsterdam, The Netherlands
| | - Irena Deperasińska
- Laser Centre Vrije Universiteit Amsterdam, The Netherlands, Department of Chemistry, University of Wroclaw, Poland, Institute of Physics, Polish Academy of Sciences, Warsaw, Poland, and Van’t Hoff Institute for Molecular Sciences, University of Amsterdam, The Netherlands
| | - Cees Gooijer
- Laser Centre Vrije Universiteit Amsterdam, The Netherlands, Department of Chemistry, University of Wroclaw, Poland, Institute of Physics, Polish Academy of Sciences, Warsaw, Poland, and Van’t Hoff Institute for Molecular Sciences, University of Amsterdam, The Netherlands
| | - Hong Zhang
- Laser Centre Vrije Universiteit Amsterdam, The Netherlands, Department of Chemistry, University of Wroclaw, Poland, Institute of Physics, Polish Academy of Sciences, Warsaw, Poland, and Van’t Hoff Institute for Molecular Sciences, University of Amsterdam, The Netherlands
| | - Wybren-Jan Buma
- Laser Centre Vrije Universiteit Amsterdam, The Netherlands, Department of Chemistry, University of Wroclaw, Poland, Institute of Physics, Polish Academy of Sciences, Warsaw, Poland, and Van’t Hoff Institute for Molecular Sciences, University of Amsterdam, The Netherlands
| | - Freek Ariese
- Laser Centre Vrije Universiteit Amsterdam, The Netherlands, Department of Chemistry, University of Wroclaw, Poland, Institute of Physics, Polish Academy of Sciences, Warsaw, Poland, and Van’t Hoff Institute for Molecular Sciences, University of Amsterdam, The Netherlands
| |
Collapse
|