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Styrylpyrimidine chromophores with bulky electron-donating substituents: experimental and theoretical investigation. Phys Chem Chem Phys 2023; 25:32699-32708. [PMID: 38014523 DOI: 10.1039/d3cp03705c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Styrylpyrimidines with bulky 9,9-dimethylacridan, phenoxazine and phenothiazine electron-donating fragments were designed. Thermally activated delayed fluorescence (TADF) properties were expected for these structures. These chromophores exhibit peculiar emission properties. For 9,9-dimethylacridan and phenoxazine derivatives, a single emission highly sensitive to the polarity is observed in solution whereas for phenothiazine derivative a dual emission is observed in solution and is attributed to the coexistence of quasi-axial (Qax) and quasi-equatorial (Qeq) conformers. This study intends to understand through theoretical and experimental works, why the studied chromophores do not exhibit TADF properties, contrary to what was expected. The absence of phosphorescence both at room temperature and 77 K tends to indicate the impossibility to harvest triplet states in these systems. Wave-function based calculations show that for both conformers of the three chromophores the S1-T1 splitting is significantly larger than 0.2 eV. The second triplet state T2 of Qeq conformers is found very close in energy to the singlet S1 state, but S1 and T2 states possess similar charge transfer characters. This prevents efficient spin-orbit coupling between the states, which is consistent with the absence of TADF.
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2
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Acidochromism of amino-substituted indolizine chromophores: towards white light emission. J Mol Liq 2023. [DOI: 10.1016/j.molliq.2023.121758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2023]
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3
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Phosphorescent cyclometalated platinum(II) complexes with phenyldiazine N^C ligands. Dalton Trans 2023; 52:1927-1938. [PMID: 36722926 DOI: 10.1039/d2dt03690h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
A series of phosphorescent platinum(II) complexes containing various phenyldiazine-type bidentate N^C ligands have been successfully synthesized and characterized. Structural modifications have been made to bidentate cyclometalating ligands regarding the nature of the diazine ring (pyrimidine, pyrazine and quinazoline), the substituent groups at the C4 position of the pyrimidine ring (OCH3, CF3) and the EDGs at the para position of the Pt atom (OCH3, Ph, NPh2, carbazol). In addition, the electronic properties of the azaheterocyclic ancillary ligand have been modulated in this series of complexes (pyridine, 4-methoxy-pyridine or pyrimidine). X-ray diffraction studies have been performed on three complexes, revealing Pt(II) ions in a distorted square-planar geometrical environment with no Pt(II)⋯Pt(II) interactions but with moderate π-π interactions in the solid-state structure. Electrochemical and computational studies suggest a ligand-centered reduction on the diazine ligands with, in some cases, additional contribution from the azaheterocyclic ancillary ligand, whereas oxidation occurs on the Pt-phenyl ring substituent moieties. All complexes exhibit phosphorescence emission ranging from green to red/near-infrared, both in solution and in the solid state. Complexes bearing a 2-(3-methoxyphenyl)pyrimidine ligand show the best PLQY of the series, up to 52% in a CH2Cl2 solution and 20% in the solid state. Furthermore, the solid state PLQY of one of the near-infrared emitting phenylquinazoline complex has been found to be 6%.
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4
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The arylvinylpyrimidine scaffold: a tunable platform for luminescent and optical materials. Org Biomol Chem 2022; 21:39-52. [PMID: 36441633 DOI: 10.1039/d2ob01841a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The incorporation of electron-withdrawing pyrimidine rings within π-extended systems allows access to a wide variety of fluorescent push-pull molecules that display emission properties highly sensitive to external stimuli. A suitable design of these compounds leads to interesting materials for a variety of optoelectronic applications. In this context, a vast number of arylvinylpyrimidine-based chromophores have been extensively studied during the last two decades. Along with the main synthetic pathways, this review summarizes the photophysical features of these active compounds having great potential and their most important applications as sensors and luminescence materials.
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5
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Vinylpyrimidine‐Functionalized Triphenylamines: Bimodal Molecular Switches and Multilevel Systems. CHEMPHOTOCHEM 2022. [DOI: 10.1002/cptc.202200201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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6
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Push–Pull Derivatives Based on 2,4′-Biphenylene Linker with Quinoxaline, [1,2,5]Oxadiazolo[3,4-B]Pyrazine and [1,2,5]Thiadiazolo[3,4-B]Pyrazine Electron Withdrawing Parts. Molecules 2022; 27:molecules27134250. [PMID: 35807494 PMCID: PMC9268487 DOI: 10.3390/molecules27134250] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Revised: 06/28/2022] [Accepted: 06/29/2022] [Indexed: 12/10/2022] Open
Abstract
A series of novel V-shaped quinoxaline, [1,2,5]oxadiazolo[3,4-b]pyrazine and [1,2,5]thiadiazolo[3,4-b]pyrazine push–pull derivatives with 2,4′-biphenylene linker were designed and their electrochemical, photophysical and nonlinear optical properties were investigated. [1,2,5]Oxadiazolo[3,4-b]pyrazine is the stronger electron-withdrawing fragment as shown by electrochemical, and photophysical data. All compounds are emissive in a solid-state (from the cyan to red region of the spectrum) and quinoxaline derivatives are emissions in DCM solution. It has been found that quinoxaline derivatives demonstrate important solvatochromism and extra-large Stokes shifts, characteristic of twisted intramolecular charge transfer excited state as well as aggregation induced emission. The experimental conclusions have been justified by theoretical (TD-)DFT calculations.
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Excited-State Intramolecular Proton Transfer in 2-(2'-Hydroxyphenyl)pyrimidines: Synthesis, Optical Properties, and Theoretical Studies. ACS APPLIED MATERIALS & INTERFACES 2022; 14:24964-24979. [PMID: 35579566 PMCID: PMC9164210 DOI: 10.1021/acsami.2c05439] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 05/05/2022] [Indexed: 06/15/2023]
Abstract
The development of fluorescence materials with switched on/off emission has attracted great attention owing to the potential application of these materials in chemical sensing. In this work, the photophysical properties of a series of original 2-(2'-hydroxyphenyl)pyrimidines were thoroughly studied. The compounds were prepared by following well-established and straightforward methodologies and showed very little or null photoluminescence both in solution and in the solid state. This absence of emission can be explained by a fast proton transfer from the OH group to the nitrogen atoms of the pyrimidine ring to yield an excited tautomer that deactivates through a nonradiative pathway. The key role of the OH group in the emission quenching was demonstrated by the preparation of 2'-unsubstituted derivatives, all of which exhibited violet or blue luminescence. Single crystals of some compounds suitable for an X-ray diffraction analysis could be obtained, which permitted us to investigate inter- and intramolecular interactions and molecular packing structures. The protonation of the pyrimidine ring by an addition of trifluoroacetic acid inhibited the excited-state intramolecular proton transfer (ESIPT) process, causing a reversible switch on fluorescence response detectable by the naked eye. This acidochromic behavior allows 2-(2'-hydroxyphenyl)pyrimidines to be used as solid-state acid-base vapor sensors and anticounterfeiting agents. Extensive density functional theory and its time-dependent counterpart calculations at the M06-2X/6-31+G** level of theory were performed to rationalize all the experimental results and understand the impact of protonation on the different optical transitions.
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Luminescent cyclometalated alkynylplatinum(II) complexes with 1,3-di(pyrimidin-2-yl)benzene ligands: synthesis, electrochemistry, photophysics and computational studies. Dalton Trans 2022; 51:5546-5560. [PMID: 35302571 DOI: 10.1039/d1dt04237h] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this article, we report on a series of cyclometalated chloro- and alkynyl-platinum(II) complexes bearing various tridentate N^C^N-cyclometalated ligands derived from 1,3-bis(pyrimidin-2-yl)benzene. The X-ray crystal structures of two alkynyl-platinum(II) complexes were determined and other structures were DFT-calculated. Electrochemical and DFT-computational studies suggest a ligand-centred reduction on the R1-substituted N^C^N ligand, whereas oxidation likely occurs either on the Pt-phenylacetylide moiety and/or the cyclometalated ligand. In CH2Cl2 solution at room temperature, the complexes show phosphorescent emissions ranging from green to orange, depending on the R1 and R2 substituents on the ligands. In KBr solid state matrix, excluding complexes bearing a trifluoromethyl substituted ligand, all compounds exhibit red emission. The presence of an alkynyl ancillary ligand has limited influence on absorption and emission spectra except in the case of the complex with the strongly electron-donating diphenylamino R2 substituent on the alkynyl ligand, for which a significant red-shift was observed. The alkynyl Pt(II) complex with OMe groups as both R1 and R2 substituents shows the best emission quantum yield (0.81 in CH2Cl2 solution) in this series. The full series of DFT calculated band gaps correlated generally well with the electrochemical and absorption data and reasonably model the impact of the substituents on the electronics of these complexes.
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9
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Synthesis, photophysical, thermal properties and X-Ray studies of novel organic dyes bearing Inden-1-ylidene and fluorene. J Photochem Photobiol A Chem 2021. [DOI: 10.1016/j.jphotochem.2021.113311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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10
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V-Shaped Methylpyrimidinium Chromophores for Nonlinear Optics. Chempluschem 2021; 86:758-762. [PMID: 33973733 DOI: 10.1002/cplu.202100081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 04/28/2021] [Indexed: 12/16/2022]
Abstract
A series of four V-shaped methylpyrimidinium salts bearing diphenylamino-electron-donating groups appended at various pyrimidine positions were designed. These chromophores were obtained by regioselective N(1) monomethylation by methyl methanesulfonate of the pyrimidine core. Linear optical properties were studied experimentally and electronic properties were further completed by (TD)-DFT calculations. The second-order nonlinear optical (NLO) properties were also studied using electric field induced second harmonic generation (EFISH) method in chloroform, and all pyrimidinium salts exhibited μβ0 >1000×10-48 esu. The 2,4-disubstituted pyrimidinium core is preferred over 4,6-disubstitution as it enhances the NLO response and increases the dipole moment. (E,E)-2,4-Bis[4-(diphenylamino)styryl]-1-methylpyrimidin-1-ium methanesulfonate appears to be the best NLO-phore in chloroform in the series (μβ0 =2500×10-48 esu) and a figure of merit μβ0 /MW=3.4 10-48 esu mol g-1 .
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11
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Cyclometallated 2‐Phenylpyrimidine Derived Platinum Complexes: Synthesis and Photophysical Properties. Eur J Inorg Chem 2021. [DOI: 10.1002/ejic.202100155] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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12
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Investigation of second-order nonlinear optical responses in a series of V-shaped binuclear platinum(ii) complexes. Dalton Trans 2021; 50:4623-4633. [PMID: 33710218 DOI: 10.1039/d1dt00151e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of four D-(π-Pt-π-A)2 new V-shaped binuclear platinum(ii) complexes bearing a diphenylpyranylidene ligand as a pro-aromatic donor group (D) and various electron-attracting groups (A) separated by platinum bis-acetylide fragments have been synthesized, characterized and studied for their electrochemical, photophysical and second-order nonlinear optical (NLO) properties. The nonlinear optical properties of these complexes have been determined by using the Electric-Field-Induced Second Harmonic (EFISH) generation technique, and their optical properties have been rationalized by Time-Dependent Density Functional Theory (TD-DFT) calculations relying on a range-separated hybrid. All complexes display positive μβ0 values. In addition, the second-order NLO responses of the complexes could be easily modulated by incorporating various end-capped electron-attracting groups, namely malononitrile, indane-1,3-dione, pyrimidine and pyrimidinium. Remarkably, complex 7 bearing a pyrimidinium fragment displays the highest μβ0 value among all the complexes of this series. Its NLO response is twice as high as that of the mononuclear analogue complex RD2, which has been confirmed both experimentally and theoretically.
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Amino-substituted-1,1-dicyano-2,4-diaryl-1,3-butadiene chromophores: Synthesis and photophysical properties. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2021; 248:119178. [PMID: 33257249 DOI: 10.1016/j.saa.2020.119178] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 10/20/2020] [Accepted: 11/01/2020] [Indexed: 06/12/2023]
Abstract
A series of D-π-A chromophores based on allylidenemalononitrile electron-withdrawing group was designed. The influence of the amino-electron-donating group on the photophysical properties was studied. These compounds, highly thermally stable, exhibit orange-red emission in solution and in solid state. The experimental results have been rationalized by theoretical DFT calculations. The second order nonlinear optical properties were also studied using the electric field induced second harmonic generation (EFISH) method.
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14
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Influence of (de)protonation on the photophysical properties of phenol-substituted diazine chromophores: experimental and theoretical studies. NEW J CHEM 2021. [DOI: 10.1039/d1nj03878h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
In this contribution, a series of seven push–pull systems has been designed by combining a protonable diazine heterocycle with a deprotonable phenol unit through various π-conjugated linkers (phenylene, thienylene, thienylenevinylene, and phenylenevinylene).
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15
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Synthesis, photophysical and nonlinear optical properties of [1,2,5]oxadiazolo[3,4-b]pyrazine-based linear push-pull systems. J Photochem Photobiol A Chem 2021. [DOI: 10.1016/j.jphotochem.2020.112900] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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16
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Photophysics of 9,9-Dimethylacridan-Substituted Phenylstyrylpyrimidines Exhibiting Long-Lived Intramolecular Charge-Transfer Fluorescence and Aggregation-Induced Emission Characteristics. Chemistry 2020; 27:1145-1159. [PMID: 33016475 DOI: 10.1002/chem.202004328] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Indexed: 01/23/2023]
Abstract
Six pyrimidine-based push-pull systems substituted at positions C2 and C4/6 with phenylacridan and styryl moieties, employing methoxy or N,N-diphenylamino donors, have been designed and synthesized through cross-coupling and Knoevenagel reactions. X-ray analysis confirmed that the molecular structure featured the acridan moiety arranged perpendicularly to the residual π system. Photophysical studies revealed significant differences between the methoxy and N,N-diphenylamino chromophores. Solvatochromic studies revealed that the methoxy derivatives showed dual emission in polar solvents. Time-resolved spectroscopy revealed that the higher energy band involved very fast (<80 ps) fluorescence, whereas the lower energy one included long components (≈30 ns) due to long-lived intramolecular charge-transfer fluorescence. In contrast to N,N-diphenylamino chromophores, the methoxy derivatives also showed aggregation-induced emission in mixtures of THF/water, as well as dual emission in thin films, covering almost the whole visible spectrum with corresponding chromaticity coordinates not far from that of pure white light. These properties render the methoxy derivatives as very promising organic materials for white organic light-emitting diodes.
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Electron‐Withdrawing Substituted Quinazoline Push‐Pull Chromophores: Synthesis, Electrochemical, Photophysical and Second‐Order Nonlinear Optical Properties. European J Org Chem 2020. [DOI: 10.1002/ejoc.202000870] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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18
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Push–Pull (Iso)quinoline Chromophores: Synthesis, Photophysical Properties, and Use for White‐Light Emission. Chemistry 2020; 26:8153-8161. [DOI: 10.1002/chem.202000817] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Indexed: 11/10/2022]
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19
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Branching effect on the linear and nonlinear optical properties of styrylpyrimidines. Phys Chem Chem Phys 2020; 22:4165-4176. [DOI: 10.1039/c9cp06476a] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The branching effect on the photophysical properties of styrylpyrimidines is studied experimentally and theoretically.
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20
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Porosity-driven large amplitude dynamics for nitroaromatic sensing with fluorescent films of alternating D-π-A molecules. Chem Commun (Camb) 2019; 55:14331-14334. [PMID: 31720604 DOI: 10.1039/c9cc07227f] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report herein the structural properties and nitroaromatic sensing performances of fluorescent thin films formed by alternating donor-acceptor π-conjugated chromophores. The incorporation of a flexible one-dimensional alkyl chain in the chromophore backbone drastically accelerates by more than one order of magnitude the sensing dynamics for the detection of 2,4-dinitrotoluene (DNT) vapors.
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21
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Functionalized benzazines as luminescent materials and components for optoelectronics. RUSSIAN CHEMICAL REVIEWS 2019. [DOI: 10.1070/rcr4887] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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22
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Tuning the Photophysical Properties of Push‐Pull Azaheterocyclic Chromophores by Protonation: A Brief Overview of a French‐Spanish‐Czech Project. CHEM REC 2019; 20:440-451. [DOI: 10.1002/tcr.201900064] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Revised: 09/20/2019] [Indexed: 12/23/2022]
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23
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Carbazole- and Triphenylamine-Substituted Pyrimidines: Synthesis and Photophysical Properties. Molecules 2019; 24:E1742. [PMID: 31060299 PMCID: PMC6540165 DOI: 10.3390/molecules24091742] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 04/23/2019] [Accepted: 05/03/2019] [Indexed: 12/12/2022] Open
Abstract
A series of pyrimidine derivatives bearing one, two or three triphenylamine/9-ethylcarbazole substituents has been synthesized by Suzuki cross-coupling reaction. All compounds showed absorption bands in the UV region and the emission of violet-blue light upon irradiation. Protonation led to quenching of the fluorescence, although some derivatives remained luminescent with the appearance of a new red-shifted band in the spectra. Accurate control of the amount of acid enabled white photoluminescence to be obtained both in solution and in solid state.
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24
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Influence of Donor-Substituents on Triphenylamine Chromophores Bearing Pyridine Fragments. European J Org Chem 2019. [DOI: 10.1002/ejoc.201900026] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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25
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Selectivity of Terpyridine Platinum Anticancer Drugs for G-quadruplex DNA. Molecules 2019; 24:molecules24030404. [PMID: 30678027 PMCID: PMC6385020 DOI: 10.3390/molecules24030404] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 01/18/2019] [Accepted: 01/22/2019] [Indexed: 01/23/2023] Open
Abstract
Guanine-rich DNA can form four-stranded structures called G-quadruplexes (G4s) that can regulate many biological processes. Metal complexes have shown high affinity and selectivity toward the quadruplex structure. Here, we report the comparison of a panel of platinum (II) complexes for quadruplex DNA selective recognition by exploring the aromatic core around terpyridine derivatives. Their affinity and selectivity towards G4 structures of various topologies have been evaluated by FRET-melting (Fluorescence Resonance Energy Transfert-melting) and Fluorescent Intercalator Displacement (FID) assays, the latter performed by using three different fluorescent probes (Thiazole Orange (TO), TO-PRO-3, and PhenDV). Their ability to bind covalently to the c-myc G4 structure in vitro and their cytotoxicity potential in two ovarian cancerous cell lines were established. Our results show that the aromatic surface of the metallic ligands governs, in vitro, their affinity, their selectivity for the G4 over the duplex structures, and platination efficiency. However, the structural modifications do not allow significant discrimination among the different G4 topologies. Moreover, all compounds were tested on ovarian cancer cell lines and normal cell lines and were all able to overcome cisplatin resistance highlighting their interest as new anticancer drugs.
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Photophysical and Protonation Time Resolved Studies of Donor–Acceptor Branched Systems With Pyridine Acceptors. J Phys Chem A 2018; 123:417-428. [DOI: 10.1021/acs.jpca.8b08628] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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27
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2,4-Distyryl- and 2,4,6-Tristyrylpyrimidines: Synthesis and Photophysical Properties. J Org Chem 2018; 83:11712-11726. [DOI: 10.1021/acs.joc.8b01653] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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28
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Mono- and Diplatinum Polyynediyl Complexes as Potential Push–Pull Chromophores: Synthesis, Characterization, TD-DFT Modeling, and Photophysical and NLO Properties. Organometallics 2018. [DOI: 10.1021/acs.organomet.8b00223] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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29
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Push-pull D-π-Ru-π-A chromophores: synthesis and electrochemical, photophysical and second-order nonlinear optical properties. Dalton Trans 2018; 47:3965-3975. [PMID: 29464264 DOI: 10.1039/c8dt00093j] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The present work describes the one-pot synthesis and electrochemical, photophysical and second-order nonlinear optical (NLO) properties of a series of dipolar π-delocalized Ru(ii) dialkynyl complexes. The eight new asymmetrical D-π-Ru-π-A push-pull chromophores incorporate pyranylidene ligands as pro-aromatic donor groups (D) and formaldehyde, indane-1,3-dione, pyrimidine or pyrimidinium as electron-attracting groups (A) separated by ruthenium bis-acetylide fragments and π-conjugated linkers. The second-order nonlinear optical (NLO) properties of all eight complexes were determined by the Electric-Field-Induced Second Harmonic generation (EFISH) technique (operating at 1907 nm), and were compared to those of their purely organic analogs. All investigated compounds (organic and organometallic) exhibited positive μβ values, which dramatically increased for the complexes due to the presence of ruthenium in the π-conjugated core. The second-order NLO response could also be easily modulated by changing the nature of alkynyl substituents. The most promising ruthenium complexes 7 and 8 of the series with the pyrimidinium fragment displayed μβ values of 14 000 × 10-48 esu. The effect of structural modifications on the redox and spectroscopic properties of the complexes was also studied. The intramolecular charge transfer (ICT) occurring through the ruthenium center of the push-pull σ-dialkynyl complexes was investigated by combining experimental and theoretical data.
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Incorporation of a platinum center in the pi-conjugated core of push-pull chromophores for nonlinear optics (NLO). Dalton Trans 2018; 46:3059-3069. [PMID: 28217794 DOI: 10.1039/c7dt00252a] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
In this article, we describe the synthesis, redox characteristics, and linear and nonlinear optical (NLO) properties of seven new unsymmetrical push-pull diacetylide platinum-based complexes. These D-π-Pt-π-A complexes incorporate pyranylidene ligands as pro-aromatic donor groups (D), diazine rings as electron-withdrawing groups (A), and various aromatic fragments (styryl or thienylvinyl) as π-linkers separating the platinum diacetylide unit from the donor and the acceptor groups. This is one of the first examples of push-pull chromophores incorporating a platinum center in the π-conjugated core. The NLO properties of these complexes were compared with those of their purely organic analogues. All compounds (organic and organometallic) exhibited positive μβ values, which dramatically increased upon methylation of the pyrimidine fragment. However, this increase was even more significant in the complexes due to the presence of platinum in the π-conjugated core. The effects of the linker on the redox and spectroscopic properties of the complexes are also discussed. In addition, DFT calculations were performed in order to gain further insight into the intramolecular charge transfer (ICT) occurring through the platinum center.
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31
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Photoluminescence Properties of Aryl-, Arylvinyl-, and Arylethynylpyrimidine Derivatives. ChemistrySelect 2018. [DOI: 10.1002/slct.201702472] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Ruthenium(II)-Catalyzed C-H (Hetero)Arylation of Alkenylic 1,n-Diazines (n = 2, 3, and 4): Scope, Mechanism, and Application in Tandem Hydrogenations. J Org Chem 2018; 83:1462-1477. [PMID: 29319315 DOI: 10.1021/acs.joc.7b03024] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A general ruthenium(II)-catalyzed methodology enabling the (hetero)arylation of alkenylic C-H bonds utilizing a series of synthetically appealing diazines as directing groups is presented. Despite the presence of additional nitrogen lone pairs remote from the C-H bond activation site, which could eventually poison the catalyst, the reaction times are short (3 h), thus being suitable for selective double C-H bond arylation. Mixtures of E:Z isomeric products were observed in some cases, which were further hydrogenated in a tandem manner in the presence of the remaining ruthenium catalyst from the first step, representing an alternative approach to more difficult C(sp3)-H bond functionalization. According to mechanistic studies, the unexpected E:Z product formation seems to occur by thermal C═C bond isomerization after the reductive elimination step.
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Triphenylamine-based allylidenemalononitrile chromophores: synthesis, and photophysical and second-order nonlinear optical properties. NEW J CHEM 2018. [DOI: 10.1039/c8nj02794c] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
A series of NLO chromophores based on a mono-, di- or tri-substituted triphenylamine core and allylidenemalononitrile fragments has been designed.
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Abstract
The synthesis of a series of push-pull derivatives bearing triphenylamine electron-donating group, cyclopenta[c]thiophen-4,6-dione electron acceptor and various π-linkers including (hetero)aromatic fragments is reported. All target chromophores with systematically varied π-linker structure were further investigated by electrochemistry, absorption measurements, and EFISH experiments in conjunction with DFT calculations. Based on electrochemical and photophysical measurements, when a polarizable 2,5-thienylene moiety is embedded into the chromophore π-backbone the highest intramolecular charge transfer (ICT) is observed. Benzene, pyrimidine, and pyridazine derivatives exhibit lower polarizability and extent of the ICT across these π-linkers. The elongation of the π-conjugated system via additional ethenylene linker results in a significant reduction of the HOMO-LUMO gap and an enhancement of the NLO response. Whereas it does not significantly influence electrochemical and linear optical properties, the orientation of the pyrimidine ring seems to be a key parameter on the μβ value due to significant variation of the dipolar moment (μ) value. In 2a and 2c, pyrimidine is oriented to behave as an acceptor and thus generate dipolar molecule with μ above 5 D, whereas in 2b and 2d ground state dipole moment is significantly reduced. This study seems to indicate a high aromaticity of pyrimidine and pyridazine derivatives, close to the benzene analogues and significantly higher than thiophene analogues.
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Synthesis and Photophysical Properties of a Series of Pyrazine-Based Push-Pull Chromophores. European J Org Chem 2016. [DOI: 10.1002/ejoc.201601204] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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36
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Styryl-based NLO chromophores: synthesis, spectroscopic properties, and theoretical calculations. Tetrahedron Lett 2015. [DOI: 10.1016/j.tetlet.2015.03.133] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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37
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Abstract
The protonation of a blue emitting pyrimidine resulted in the formation of an orange emissive acidified form. In adequate proportion of neutral and protonated forms, white light emission is observed both in solution and in polystyrene thin film.
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Donor–linker–acceptor (D–π–A) diazine chromophores with extended π-conjugated cores: synthesis, photophysical and second order nonlinear optical properties. RSC Adv 2015. [DOI: 10.1039/c5ra05736a] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The synthesis, photophysical properties and second order non-linear optical response of a series of push–pull pyrimidine and quinoxaline chromophores with extended π-conjugated cores are reported.
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Synthesis and Photophysical Studies of a Series of Quinazoline Chromophores. J Org Chem 2014; 79:7564-71. [DOI: 10.1021/jo501305h] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Correction to Synthesis and Characterization of Glycoconjugated Porphyrin Triphenylamine Hybrids for Targeted Two-Photon Photodynamic Therapy. J Org Chem 2014. [DOI: 10.1021/jo500315m] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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43
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Synthesis and Characterization of Glycoconjugated Porphyrin Triphenylamine Hybrids for Targeted Two-Photon Photodynamic Therapy. J Org Chem 2014; 79:1406-17. [DOI: 10.1021/jo402658h] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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44
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Glycoconjugated porphyrin dimers as robust ratiometric temperature sensors. Chem Commun (Camb) 2014; 50:9529-32. [DOI: 10.1039/c4cc03367a] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
We report the properties of glycoconjugated porphyrin dimers behaving as highly sensitive ratiometric temperature sensors in water.
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Synthesis and Photophysical Properties of Push-Pull Structures Incorporating Diazines as Attracting Part with a Fluorene Core. European J Org Chem 2013. [DOI: 10.1002/ejoc.201300458] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Synthesis, Photophysics and Nonlinear Optical Properties of Stilbenoid Pyrimidine‐Based Dyes Bearing Methylenepyran Donor Groups. Chemphyschem 2013; 14:2725-36. [DOI: 10.1002/cphc.201300419] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2013] [Indexed: 11/08/2022]
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Synthesis and photophysical investigation of a series of push-pull arylvinyldiazine chromophores. J Org Chem 2012; 77:4087-96. [PMID: 22475074 DOI: 10.1021/jo3004919] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A new series of push-pull arylvinyldiazines has been efficiently prepared by aldol condensation between the appropriate methyldiazine and aromatic aldehyde. The optical absorption and emission properties of these chromophores were studied in different solvents and media. These compounds act as polarity sensors with a strong positive emission solvatochromism. This behavior suggests a highly polar emitting state, which is characteristic of compounds that undergo an internal charge transfer upon excitation. These molecules also exhibit halochromic properties and are potential colorimetric and luminescence pH sensors. The second-order nonlinear properties have been investigated for some of the compounds, and large and positive μβ are obtained, in particular, for pyrimidine derivatives.
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Abstract
We report the synthesis of a series of zinc porphyrins conjugated with pyrimidine derivatives. V shaped porphyrin dimer with a pyrimidine central core exhibits a planar geometry according to DFT computational studies, presents an internal charge transfer upon excitation proved by typical solvatochromic behavior and moderate two-photon absorption properties. Such porphyrin conjugates can afford valuable advantages in applications of TPA materials such as in photodynamic therapy and imaging of biological entities.
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