Styryl-based new organic chromophores bearing free amino and azomethine groups: synthesis, photophysical, NLO, and thermal properties

Herein we report the synthesis and characterization of a new series of styryl-based push-pull dyes containing a free amino group and their Schiff base derivatives. The dyes include the dicyanomethylene group as an acceptor and different para-substituted alkylamines as donors. Morever as a proton-sensitive group a pyridin-2-yl substituent was attached to the para-position of the phenyl moiety in both series of compounds. The photophysical properties of the dyes were examined in various solvents with different polarities and showed absorption in the visible region and green-red emission with low quantum yields. The absorption and the emission maxima were shifted bathocromically by increasing the solvent’s polarity. However, there was no correlation with the polarity parameters of the solvents. The pH-sensitive properties of all prepared Schiff bases were examined against TBAOH in DMSO, via deprotonation of the OH group in the salicylidene moiety and their reverse protonation was also investigated using TFA. The Schiff bases exhibited a bathochromic shift upon the addition of TBAOH to their solutions in DMSO. Therefore, they showed potential to be utilized as colorimetric and luminescence pH sensors. The second-order nonlinear optical (NLO) responses of the dyes were measured by the electric field-induced second harmonic (EFISH) generation method. The highest μβ values were obtained for the dyes bearing the julolidine donor as 1430 × 10−48 esu (for free amino derivative) and 1950 × 10−48 esu (for Schiff base derivative), respectively. The structural and electronic properties of the dyes as well as their NLO properties were further studied using DFT calculations. The thermal stabilities of all dyes were evaluated by thermogravimetric analysis (TGA). The TGA data showed that all dyes were thermally stable up to 250 °C.

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New styryl based organic chromophores including free amino and azomethine groups: Syntheses, photophysical, NLO and thermal properties

10.3762/bxiv.2020.30.v1 ◽

2020 ◽

Author(s):

Anka Utama Putra ◽

Deniz Çakmaz ◽

Nurgül Seferoğlu ◽

Alberto Barsella ◽

Zeynel Seferoğlu

Keyword(s):

Thermal Properties ◽

Schiff Bases ◽

Free Amino ◽

Photophysical Properties ◽

Visible Region ◽

Fluorescence Emission ◽

Inert Atmosphere ◽

Quantum Yields ◽

Good Thermal Stability ◽

Nlo Property

In this manuscript, we have successfully synthesized and characterized a new series of styryl based push-pull dyes containing free amino group and their Schiff bases derivatives in which dicyanomethylene was used as the acceptor group and different para-substituted alkylamines as the donor groups and 2-pyridyl as proton sensitive group. All compounds showed absorption in the visible region and green-red emission with low quantum yields. The photophysical properties were examined in various solvents with different polarities. The absorption and emission maxima were shifted bathocromically by increasing solvents polarity however, there was no regular correlation with polarity parameter. Significant red shifts were observed in the absorption and fluorescence emission maxima on increasing the electron-donating ability of the substituents. The observed color changes were photographed naked eyes and under illuminating UV-lamp. The pH sensitive properties of newly prepared Schiff bases against TBAOH were examined inside DMSO, furthermore their reserve protonation were also investigated using TFA. The structural and electronic properties of all newly synthesized compounds were studied using DFT calculation. In addition, NLO property of compounds were investigated by DFT. For determination thermal properties of all compounds were investigated and they showed good thermal stability up to 250 oC by TGA analyses under inert atmosphere. Our results indicate that the styryl based new push-pull dyes are promising candidate materials for NLO and pH applications.

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Facile luminescent tuning of ZnII/HgII complexes based on flexible, semi-rigid and rigid polydentate Schiff bases from blue to green to red: structural, photophysics, electrochemistry and theoretical calculations studies

Dalton Transactions ◽

10.1039/c5dt00057b ◽

2015 ◽

Vol 44 (17) ◽

pp. 8107-8125 ◽

Cited By ~ 13

Author(s):

Xin-Ming Wang ◽

Shuo Chen ◽

Rui-Qing Fan ◽

Fu-Qiang Zhang ◽

Yu-Lin Yang

Keyword(s):

Schiff Base ◽

Schiff Bases ◽

Theoretical Calculations ◽

Photophysical Properties ◽

Schiff Base Complexes

The photophysical properties of ZnII/HgII Schiff base complexes could be tuned by changing the ligand structures.

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Ethyne Functionalized Meso-Phenothiazinyl-Phenyl-Porphyrins: Synthesis and Optical Properties of Free Base Versus Protonated Species

Molecules ◽

10.3390/molecules25194546 ◽

2020 ◽

Vol 25 (19) ◽

pp. 4546

Author(s):

Eva Molnar ◽

Emese Gál ◽

Luiza Găină ◽

Castelia Cristea ◽

Luminița Silaghi-Dumitrescu

Keyword(s):

Absorption Spectra ◽

Density Functional ◽

Photophysical Properties ◽

Bathochromic Shift ◽

Fluorescence Emission ◽

Soret Band ◽

Quantum Yields ◽

Free Base ◽

Wave Absorption ◽

Long Wave

Synthesis, structural characterization and photophysical properties for a series of new trans-A2B2- and A3B-type ethynyl functionalized meso-phenothiazinyl-phenyl porphyrin derivatives are described. The new compounds displayed the characteristic porphyrin absorption spectra slightly modified by weak auxochromic effects of the substituents and fluorescence emission in the range of 651–659 nm with 11–25% quantum yields. The changes recorded in the UV-vis absorption spectra in the presence of trifluoroacetic acid (TFA) are consistent with the protonation of the two internal nitrogen atoms of the free-base porphyrin (19 nm bathochromic shift of the strong Soret band and one long wave absorption maxima situated in the range of 665–695 nm). Protonation of the phenothiazine substituents required increased amounts of TFA and produced a distinct hypsochromic shift of the long wave absorption maxima. The density functional theory (DFT) calculations of a porphyrin dication pointed out a saddle-distorted porphyrin ring as the ground-state geometry.

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New red-emitting Schiff base chelates: promising dyes for sensing and imaging of temperature and oxygen via phosphorescence decay time

Journal of Materials Chemistry C ◽

10.1039/c8tc02726a ◽

2018 ◽

Vol 6 (33) ◽

pp. 8999-9009 ◽

Cited By ~ 15

Author(s):

Sergey M. Borisov ◽

Reinhold Pommer ◽

Jan Svec ◽

Sven Peters ◽

Veronika Novakova ◽

...

Keyword(s):

Schiff Base ◽

Schiff Bases ◽

Optical Sensors ◽

Decay Time ◽

Photophysical Properties ◽

Phosphorescence Decay ◽

One Step

New complexes of Zn(ii), Pd(ii) and Pt(ii) with Schiff bases are prepared in a one step reaction and show photophysical properties particularly interesting for applications in optical sensors.

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Host-guest complexes of anionic porphyrin sensitizers with cyclodextrins

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s1088424602000646 ◽

2002 ◽

Vol 06 (08) ◽

pp. 514-526 ◽

Cited By ~ 20

Author(s):

Jiří Mosinger ◽

Viktor Kliment ◽

Jan Sejbal ◽

Pavel Kubát ◽

Kamil Lang

Keyword(s):

Singlet Oxygen ◽

Specific Binding ◽

Photophysical Properties ◽

Bathochromic Shift ◽

Fluorescence Emission ◽

Binding Constants ◽

Quantum Yields ◽

Hydroxyl Groups ◽

Triplet States ◽

Binding Modes

The photodynamic sensitizers zinc(II)- and palladium(II)-5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrins and 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin form 1:1 and/or 1:2 supramolecular complexes with native cyclodextrins (CD) and 2-hydroxypropyl cyclodextrins (hpCD) in aqueous neutral solutions. The formation of these assemblies causes a bathochromic shift of the porphyrin Soret band in the UV-vis spectra and a red shift of the fluorescence emission bands. The binding constants span over three orders of magnitude, from 8.1 × 102 M −1 to 5.4 × 105 M −1 (or 1.1 × 106 M −2) depending on the size of the CD cavity and on the functionalization by adding 2-hydroxypropyl groups. The highest binding constants were obtained for hpβCD and hpγCD. The Nuclear Overhauser spectroscopy signals (ROESY) revealed three binding modes: i) inclusion of the porphyrin 4-sulfonatophenyl or 4-carboxyphenyl groups via the secondary face of βCD and hpβCD with sulfonic or carboxylic groups oriented towards the primary hydroxyl groups. ii) inclusion of the porphyrin groups via the primary face of γCD and hpγCD. iii) non-specific binding of the porphyrin monomers or aggregates on the cyclodextrin exterior. The inclusion host-guest complexation via i) or ii) does not influence the inherent photophysical properties of the monomeric porphyrins such as the quantum yields of fluorescence, the triplet states, and the singlet oxygen formation. Due to the deaggregation effect of cyclodextrins, the inclusion complexes remain efficient supramolecular sensitizers of singlet oxygen even under conditions of extensive aggregation in aqueous solutions.

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Mesomorphic Behaviour and DFT Insight of Arylidene Schiff Base Liquid Crystals and Their Pyridine Impact Investigation

Crystals ◽

10.3390/cryst11080978 ◽

2021 ◽

Vol 11 (8) ◽

pp. 978

Author(s):

Mohamed A. Zakaria ◽

Mohammed Alazmi ◽

Kanubhai D. Katariya ◽

Yeldez El Kilany ◽

El Sayed H. El Ashry ◽

...

Keyword(s):

Schiff Base ◽

Chain Length ◽

Schiff Bases ◽

Density Functional ◽

Theoretical Calculations ◽

Strong Impact ◽

Polarization Optical Microscopy ◽

Thermal Stabilities ◽

New Compounds ◽

Base Liquid

A new series of Schiff base liquid crystal have been prepared and studied. Schiff bases of p-alkyl aniline derivatives and 4-phenyl pyridine-4′-carbaldehyde were prepared. The terminal alkyl groups substituting aniline are of varied chain length, namely C8, C12 and C14. The structures of the compounds were elucidated by 1H NMR and 13C NMR. The mesomorphic thermal and optical characteristics of the samples were determined via differential thermal analysis (DSC) and polarization optical microscopy (POM). All compounds exhibit enantiotropic dimorphic mesophase behaviour, referred to as smectic X1 (SmX1) and smectic X2 (Sm A). Experimental results obtained for the mesophases were correlated with density functional theory (DFT) theoretical calculations. The results of the new series are further compared to two series of compounds bearing pyridine (two ring Schiff bases) and biphenyl, respectively, in their mesogens. The series of compounds of one pyridine ring are generally not mesomorphic. The results indicate that the alkyl chain length has a strong impact on the mesomorphic characteristics and thermal stabilities of the different mesophases. As a trend, the temperature ranges of both of smectic mesophases of all compounds are higher in new compounds bearing the 4-phenyl pyridine moiety. In addition, the total mesophase range is generally higher in the new compounds when compared to their biphenyl analogues. Finally, theoretical DFT calculations were performed to illustrate the experimental finding of the mesomorphic behaviour in terms of the molecular geometry and aromaticity, π–π stacking and LOL-π.

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Design of Novel Pyrene-Bodipy Dyads: Synthesis, Characterization, Optical Properties, and FRET Studies

Molecules ◽

10.3390/molecules23092289 ◽

2018 ◽

Vol 23 (9) ◽

pp. 2289 ◽

Cited By ~ 4

Author(s):

Pasquale Porcu ◽

Mireille Vonlanthen ◽

Israel González-Méndez ◽

Andrea Ruiu ◽

Ernesto Rivera

Keyword(s):

First Generation ◽

Photophysical Properties ◽

Visible Region ◽

Resonance Energy Transfer ◽

Resonance Energy ◽

Spectroscopic Studies ◽

Quantum Yields ◽

Acceptor Pair ◽

Donor Acceptor ◽

Zero Generation

A new series of dendronized bodipys containing pyrene units was synthesized and characterized. Their optical and photophysical properties were determined by absorption and fluorescence spectroscopy. This series includes three different compounds. The first one has an anisole group linked to the bodipy unit, which was used as the reference compound. In the second, the bodipy core is linked to a zero generation dendron with one pyrene unit. The third compound contains a first generation Fréchet-type dendron bearing two pyrene units. In this work, the combination pyrene-bodipy was selected as the donor-acceptor pair for this fluorescence resonance energy transfer (FRET) study. Doubtless, these two chromophores exhibit high quantum yields, high extinction coefficients, and both their excitation and emission wavelengths are located in the visible region. This report presents a FRET study of a novel series of pyrene-bodipy dendritic molecules bearing flexible spacers. We demonstrated via spectroscopic studies that FRET phenomena occur in these dyads.

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Conjugated-linker dependence of the photophysical properties and electronic structure of chlorin dyads

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s1088424621500620 ◽

2021 ◽

pp. A-Y

Author(s):

Hyun Suk Kang ◽

Andrius Satraitis ◽

Adam Meares ◽

Ganga Viswanathan Bhagavathy ◽

James R. Diers ◽

...

Keyword(s):

Electronic Structure ◽

Excited State ◽

Photophysical Properties ◽

Bathochromic Shift ◽

Fluorescence Yield ◽

Quantum Yields ◽

Design Strategies ◽

Long Wavelength ◽

Fluorescence Quantum Yields ◽

Wavelength Absorption

The synthesis, photophysical properties and electronic structure of seven new chlorin dyads and associated benchmark monomers are described. Each dyad contains two identical chlorins linked at the macrocycle [Formula: see text]-pyrrole 13-position. The extent of electronic communication between chlorin constituents depends on the nature of the conjugated linker. The communication is assessed by modification of prominent ground-state absorption and redox properties, rate constants and yields of excited-state decay processes, and molecular-orbital characteristics. Relative to the benchmark monomers, the chlorin dyads in toluene exhibit a substantial bathochromic shift of the long-wavelength absorption band (30 nm average), two-fold increased radiative rate constant [average (10 ns)[Formula: see text] vs. (22 ns)[Formula: see text]], reduced singlet excited-state lifetimes (average 5.0 ns vs. 8.2 ns), and increased fluorescence quantum yields (average 0.56 vs. 0.42). The excited-state lifetime and fluorescence yield for the chlorin dyad with a benzothiadiazole linker are reduced substantially in benzonitrile vs. toluene due largely to [Formula: see text]25-fold accelerated internal conversion. The results aid design strategies for molecular architectures that may find utility in solar-energy conversion and photomedicine.

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PDT-related photophysical properties of conformationally distorted palladium(II) porphyrins

Journal of Porphyrins and Phthalocyanines ◽

10.1002/jpp.553 ◽

2001 ◽

Vol 05 (12) ◽

pp. 853-860 ◽

Cited By ~ 27

Author(s):

A. WIEHE ◽

H. STOLLBERG ◽

S. RUNGE ◽

A. PAUL ◽

M. O. SENGE ◽

...

Keyword(s):

Quantum Yield ◽

Molecular Oxygen ◽

Photophysical Properties ◽

Bathochromic Shift ◽

Luminescence Spectroscopy ◽

Quantum Yields ◽

Triplet States ◽

Singlet Molecular Oxygen ◽

Time Resolved ◽

Phosphorescence Quantum Yield

The photodynamic therapy (PDT) related photophysical properties of five palladium(II) porphyrins with increasing steric demand of the meso-substituents were investigated by steady state and time-resolved absorption and luminescence spectroscopy. The steric strain of the meso-substituents is reflected in a bathochromic shift of the B-band in the absorption spectra. In contrast to free-base porphyrins, the palladium(II) complexes exhibit only a very weak fluorescence with Φ Fl ~ 10-4. Instead, the corresponding triplet states of the porphyrins are formed via inter system crossing (ISC) with a quantum yield ΦISC of nearly unity. A phosphorescence quantum yield ΦISC of 10-4 was determined assuming dynamic quenching. The triplet state of all compounds is efficiently quenched by molecular oxygen, generating singlet molecular oxygen with a quantum yield of ΦΔ ~ 0.85. The various substitution patterns exerted no significant influence on the ISC rates or singlet oxygen quantum yields. Significant differences, on the other hand, were observed with respect to the triplet lifetimes, with a tendency of longer lifetimes for the porphyrins with sterically more demanding substituents (in air-saturated solution). All porphyrins were successfully incorporated into liposomes. The phototoxic activity of three compounds was investigated in cell suspensions. The use of the new porphyrinato-palladium(II) in PDT applications is discussed.

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Regioselective Oxidative Cross-Coupling Reaction: Synthesis of Imidazo[1,2-a]pyridine Fluorophores

Synthesis ◽

10.1055/s-0040-1706000 ◽

2021 ◽

Author(s):

Xianglong Chu ◽

Yadi Niu ◽

Chen Ma ◽

Xiaodong Wang ◽

Yunliang Lin ◽

...

Keyword(s):

Photophysical Properties ◽

Coupling Reaction ◽

Cross Coupling ◽

Quantum Yields ◽

Fluorescence Quantum Yields ◽

Cross Coupling Reaction ◽

Color Tunable ◽

Palladium Catalyzed ◽

Structure Relationship ◽

High Fluorescence

AbstractA rapid access to a series of N-heteroarene fluorophores has been developed on the basis of the palladium-catalyzed direct oxidative C–H/C–H coupling of imidazo[1,2-a]pyridines with thiophenes/furans. The photophysical properties–structure relationship was systematically investigated. The resulting N-heteroarene fluorophores present color-tunable emissions (λem: 431–507 nm in CH2Cl2) and high fluorescence quantum yields (up to 91% in CH2Cl2).

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