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Tamaki A, Kojima S, Yamamoto Y. Examination of Pyridazine as a Possible Scaffold for Nucleophilic Catalysis. J Org Chem 2016; 81:8710-8721. [PMID: 27494050 DOI: 10.1021/acs.joc.6b00630] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Pyridazines with amino groups positioned para to each aromatic ring nitrogen and fixed in six-membered rings were prepared. The representative symmetric amino N-Et derivative was found to slightly exceed DMAP in catalytic activity in the acetylation reaction of a tertiary alcohol in C6D6. Nucleophilicity eclipsing that of DMAP was established in competitive reactions using phenacyl bromide as the electrophile, and the unsymmetric N-Et derivative was revealed to have even higher nucleophilicity.
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Affiliation(s)
- Airi Tamaki
- Department of Chemistry, Graduate School of Science, Hiroshima University , 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Japan
| | - Satoshi Kojima
- Department of Chemistry, Graduate School of Science, Hiroshima University , 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Japan.,Center for Quantum Life Sciences, Hiroshima University , 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Japan
| | - Yohsuke Yamamoto
- Department of Chemistry, Graduate School of Science, Hiroshima University , 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Japan
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2
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Dual fluorescence of 4-(dimethylamino)-pyridine: a comparative linear response TDDFT versus state-specific CASSCF study including solvent with the PCM model. Theor Chem Acc 2015. [DOI: 10.1007/s00214-015-1659-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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3
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López-de-Luzuriaga JM, Manso E, Monge M, Olmos ME, Rodríguez-Castillo M, Sampedro D. The effect of gold(i) coordination on the dual fluorescence of 4-(dimethylamino)pyridine. Dalton Trans 2015; 44:11029-39. [DOI: 10.1039/c5dt00584a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Coordination of 4-(dimethylamino)pyridine to perhalophenyl gold(i) fragments leads to the formation of novel fluorescent complexes, in which the photophysical properties of the ligand are greatly influenced by the polarity induced by the organometallic fragment.
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Affiliation(s)
- José M. López-de-Luzuriaga
- Departamento de Química
- Universidad de La Rioja
- Centro de Investigación en Síntesis Química (CISQ)
- Complejo Científico-Tecnológico
- 26004-Logroño
| | - Elena Manso
- Departamento de Química
- Universidad de La Rioja
- Centro de Investigación en Síntesis Química (CISQ)
- Complejo Científico-Tecnológico
- 26004-Logroño
| | - Miguel Monge
- Departamento de Química
- Universidad de La Rioja
- Centro de Investigación en Síntesis Química (CISQ)
- Complejo Científico-Tecnológico
- 26004-Logroño
| | - M. Elena Olmos
- Departamento de Química
- Universidad de La Rioja
- Centro de Investigación en Síntesis Química (CISQ)
- Complejo Científico-Tecnológico
- 26004-Logroño
| | - María Rodríguez-Castillo
- Departamento de Química
- Universidad de La Rioja
- Centro de Investigación en Síntesis Química (CISQ)
- Complejo Científico-Tecnológico
- 26004-Logroño
| | - Diego Sampedro
- Departamento de Química
- Universidad de La Rioja
- Centro de Investigación en Síntesis Química (CISQ)
- Complejo Científico-Tecnológico
- 26004-Logroño
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4
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LI JUANQIN, LI XIANGYUAN, WANG FENG. A THEORETICAL STUDY ON DUAL FLUORESCENCE OF 4-DIMETHYLAMINOPYRIDINE BY POLARIZABLE CONTINUUM MODEL. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2011. [DOI: 10.1142/s0219633608004143] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Dual fluorescence spectra of 4-dimethylaminopyridine (DMAP) is investigated using time-dependent density functional theory and complete active space self-consistent field methods. Electronic absorption and emission spectra of DMAP have been investigated in three solvents, that is, cyclohexane, chloroform, and acetonitrile. The present study reveals that the dual fluorescence phenomena of DMAP appear in the cases of acetonitrile and chloroform, but not in cyclohexane. The electronic structures of the ground state and the intramolecular charge transfer states are, therefore, studied in order to reveal the insight of dual fluorescence. Our theoretical results suggest that the twisting of dimethylamino moiety in DMAP is necessary for the intramolecular charge transfer. The mechanism of the dual fluorescence of DMAP is discussed based on the twisted intramolecular charge transfer model and the dual fluorescence phenomenon is explained theoretically.
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Affiliation(s)
- JUAN-QIN LI
- College of Chemical Engineering and State Key Laboratory of Biotherapy, Sichuan University, Chengdu 610065, P. R. China
| | - XIANG-YUAN LI
- College of Chemical Engineering and State Key Laboratory of Biotherapy, Sichuan University, Chengdu 610065, P. R. China
| | - FENG WANG
- Center for Molecular Simulation, Swinburne University of Technology, Hawthorn, Melbourne, Vic. 3122, Australia
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Structural changes accompanying excited-state electron transfer in meta- and para-dialkylaminopyridines. J Photochem Photobiol A Chem 2010. [DOI: 10.1016/j.jphotochem.2009.11.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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6
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Mile V, Demeter A, Tóth G. Quantum chemical study of the ground-state alcoholic complexation of selected dual luminescent compounds. Mol Phys 2009. [DOI: 10.1080/00268970903084953] [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]
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7
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Theoretical studies on the electronic structures and absorption spectra of substituted benzenes with one- and two-dimensional charge transfer character. ACTA ACUST UNITED AC 2008. [DOI: 10.1016/j.theochem.2008.09.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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8
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Franssen Szydłowska I, Nosenko Y, Brutschy B, Herbich J. Dual fluorescence of 4-dialkylaminopyridines under supersonic jet conditions. Chem Phys Lett 2008. [DOI: 10.1016/j.cplett.2008.11.027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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9
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Demeter A, Mile V, Bérces T. Hydrogen Bond Formation between 4-(Dimethylamino)pyridine and Aliphatic Alcohols. J Phys Chem A 2007; 111:8942-9. [PMID: 17718545 DOI: 10.1021/jp072989i] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The photophysics of 4-(dimethylamino)pyridine (DMAP) has been investigated in different solvents in the presence of aliphatic and fluorinated aliphatic alcohols, respectively. For most systems, consecutive two-step hydrogen-bonded complex formation is observed in the presence of alcohols. Equilibrium constants are determined from UV spectroscopic results for the formation of singly and doubly complexed species. The resolved absorption and fluorescence spectra for the singly and doubly complexed DMAP are derived by means of the equilibrium constants. Exceptionally large hydrogen bond basicity values are found for the ground and singlet excited DMAP molecules. In n-hexane, as a consequence of complex formation, the intramolecular charge transfer (ICT) emission becomes dominant over of the locally excited fluorescence; the fluorescence and triplet yields increase considerably with complexation. In polar solvents, both the fluorescence and triplet yields of the complex are much smaller than that of the uncomplexed DMAP. The dipole moments derived for the singly complexed species from the Lippert-Mataga analysis are much larger than those of the uncomplexed molecules. However, for the relaxed ICT excited-state one obtains different dipole moments in apolar and polar solvents. This may be explained by a conformational change of the molecule in the ICT excited state from planar geometry in apolar solvent to the perpendicular structure (characterized with bigger dipole moment) in polar solvent.
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Affiliation(s)
- Attila Demeter
- Institute of Materials and Environmental Chemistry, Chemical Research Center, Hungarian Academy of Sciences, 1025 Budapest, Pusztaszeri u. 59-67, Hungary.
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Bangal PR. Density Functional Studies on the Effects of Hydrogen Bonding on the Formation of a Charge-Transfer Complex betweenp-Benzoquinone and 2,6-Dimethoxyphenol. J Phys Chem A 2007; 111:5536-43. [PMID: 17539618 DOI: 10.1021/jp071612+] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The ability to form a ground-state charge-transfer (CT) complex between an electron acceptor, p-benzoquinone (BQ) and an electron donor, 2,6-dimethoxyphenol (DMOPh) was found to be enhanced by H-bonding of BQ to a hydrogen-bond donor, trifluoroacetic acid (TFA) and H-bonding DMOPh to a hydrogen-bond acceptor, 4-(N,N-dimethylamino)pyridine (DMAPy) [Chem. Phys. Lett. 2005, 401, 200]. Here is reported density functional theory (DFT) calculations to study the effect of H-bonding to electron donor and electron acceptor moieties on the ground-state CT complex formation ability between the aforementioned electron donor/acceptor pair. DFT calculations using B3LYP with the 6-311G(d,p) basis set show that the HOMO and LUMO energies of BQ drop on H-bonding to TFA through its C=O groups and the HOMO and LUMO energies of DMOPh increase on H-bonding to DMAPy via its O-H group. BQ molecules hydrogen-bonded as 1:1 and 1:2 complexes to TFA act as stronger acceptors than the bare molecule, while 1:1 complexes of DMOPh and DMAPy act as better donors. Vertical excitation energies for electronic transitions from the ground state to the first few excited states of BQ, DMOPh, DMAPy, and their different complexes have been investigated in the framework of time-dependent density functional theory (TD-DFT) to simulate and interpret experimental ultraviolet absorption spectra. Good agreement between experimental and calculated spectra is established. The enhancement of the CT complex formation ability between the BQ and DMOPh pair is favored by the strong H-bonding interaction of BQ with TFA as well as by the H-bonding interaction of DMOPh with DMAPy.
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Affiliation(s)
- Prakriti Ranjan Bangal
- Inorganic and Physical Chemistry Division, Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500007, India.
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11
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Abramov S, Schweke D, Zilberg S, Haas Y. The fluorescence of 5-cyano-2-(1-pyrrolyl)-pyridine (CPP) in different solvents and in solid argon: An experimental and theoretical study. Chem Phys 2007. [DOI: 10.1016/j.chemphys.2007.03.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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12
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Szydłowska I, Nosenko Y, Brutschy B, Tarakeshwar P, Herbich J. Supersonic jet studies of solvation effects on the spectroscopy and photophysics of 4-diethylaminopyridine. Phys Chem Chem Phys 2007; 9:4981-91. [PMID: 17851594 DOI: 10.1039/b705532c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We present the results of spectroscopic and photophysical investigations of 4-diethylaminopyridine (DEAP) and its 1 : 1 complexes with a number of protic solvents such as water and various alcohols of different acidity isolated under supersonic jet conditions. While a double resonance vibrational spectroscopic method was employed to investigate the size and geometrical structure of jet-cooled clusters, laser-induced fluorescence spectroscopy was used to examine the changes of photophysics induced by complexation of DEAP with solvent molecule(s). The results obtained from ab initio calculations enable the assignment of geometries and of the vibrational spectra of the clusters in the OH-stretch region. The comparison of the experimental and calculated vibrational spectra indicates that the solvent molecule is hydrogen-bonded to the pyridine nitrogen atom. Dual luminescence is observed only for the complexes with alcohols of relatively strong acidity.
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Affiliation(s)
- Izabela Szydłowska
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland
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Gandubert VJ, Lennox RB. Assessment of 4-(dimethylamino)pyridine as a capping agent for gold nanoparticles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:6532-9. [PMID: 15982063 DOI: 10.1021/la050195u] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Gold nanoparticles stabilized with 4-(dimethylamino)pyridine (DMAP) were prepared by ligand exchange and phase transfer (toluene/water) of functionalized gold nanoparticles. DMAP-protected gold nanoparticles are water-soluble, positively charged, and fairly monodisperse (6.2 +/- 0.9 nm). To understand the scope of this interesting system, the details of the binding of DMAP to gold nanoparticles were investigated. The adsorption of DMAP onto gold surfaces was studied by electrochemistry and surface plasmon resonance. It is concluded that of the three most likely binding modes, the one involving the pyridine nitrogen binding to the gold surface, as suggested previously (Gittins, D. I.; Caruso, F. Angew. Chem., Int. Ed. 2001, 40, 3001), is consistent with experimental data. Other 4-substituted pyridines were also assessed as capping agents. The solubility in toluene and basicity of the incoming ligand, as well as the ability to form charged nanoparticles, determine whether ligand exchange and subsequent phase transfer of the nanoparticles occur. The solubility and stability of the DMAP-protected gold nanoparticles were studied as a function of pH using UV-visible spectroscopy and transmission electron microscopy (TEM). These nanoparticles are soluble and stable over a wide pH range (5.0-12.8). It was found that excess DMAP is necessary for both the preparation and the stability of the DMAP-protected gold nanoparticles.
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Affiliation(s)
- Valérie J Gandubert
- Department of Chemistry and Centre for Self Assembled Chemical Structures (CSACS), McGill University, 801 Sherbrooke Street West, Montréal, Québec H3A 2K6, Canada
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Furche F, Rappoport D. Density Functional Methods for Excited States: Equilibrium Structure and Electronic Spectra. THEORETICAL AND COMPUTATIONAL CHEMISTRY 2005. [DOI: 10.1016/s1380-7323(05)80020-2] [Citation(s) in RCA: 167] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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15
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Szydłowska I, Kubicki J, Herbich J. Picosecond kinetics of excited-state charge separation in 4-(dimethylamino)pyridine. Photochem Photobiol Sci 2005; 4:106-12. [PMID: 15616700 DOI: 10.1039/b411627e] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
4-(Dimethylamino)pyridine (DMAP) shows solvent-dependent dual fluorescence from the initially excited state B* and a highly polar TICT state A*. Room-temperature time-resolved picosecond fluorescence investigations prove the bimodal kinetics of the excited-state electron transfer reaction B*-->A* in polar aprotic media. In medium polarity solvents (such as ethyl acetate) two emitting states of DMAP are shown to reach equilibrium within 50 ps. Both emitting states originate from the same ground state. The rate of excited-state charge separation depends on polarity and proton donating ability of the surrounding medium. The effects of temperature on the quantum yields of both fluorescences of DMAP in polar aprotic media indicate the transition from the kinetic regime (at low temperatures) to the equilibrium regime (at high temperatures). The kinetic behaviour of the dual luminescence of DMAP in protic solvents is more complex than in aprotic ones. In alcohols an efficient nonradiative channel competes with excited-state charge separation.
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Affiliation(s)
- Izabela Szydłowska
- Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland
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