Steady-state fluorescence and photo-isomerization study of 1-methyl-4′-(p-N,N dimethyl-amino styryl) pyridinium iodide

Abdel-Halim, Shakir T.

doi:10.1016/j.jlumin.2010.08.022

Cited by 10 publications

(12 citation statements)

References 53 publications

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“…pyridinium) and the other is electron rich (e.g. p-N,N-dimethylaniline) (3,5,7,8). The resulting push-pull nature supports the quinonoid resonance form (at right); however, the quinonoid resonance form contributes only weakly (and in a medium-dependent manner) to the electronic structure of the dye.…”

Section: Introductionmentioning

confidence: 89%

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Integration of Cyanine, Merocyanine and Styryl Dye Motifs with Synthetic Bacteriochlorins

Yang

Zhang

Krayer

et al. 2015

Photochem & Photobiology

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Understanding the effects of substituents on spectral properties is essential for the rational design of tailored bacteriochlorins for light-harvesting and other applications. Toward this goal, three new bacteriochlorins containing previously unexplored conjugating substituents have been prepared and characterized. The conjugating substituents include two positively charged species, 2-(N-ethyl 2-quinolinium)vinyl- (B-1) and 2-(N-ethyl 4-pyridinium)vinyl- (B-2), and a neutral group, acroleinyl- (B-3); the charged species resemble cyanine (or styryl) dye motifs whereas the neutral unit resembles a merocyanine dye motif. The three bacteriochlorins are examined by static and time-resolved absorption and emission spectroscopy and density functional theoretical calculations. B-1 and B-2 have Qy absorption bathochromically shifted well into the NIR region (822 and 852 nm), farther than B-3 (793 nm) and other 3,13-disubstituted bacteriochlorins studied previously. B-1 and B-2 have broad Qy absorption and fluorescence features with large peak separation (Stokes shift), low fluorescence yields, and shortened S1 (Qy ) excited-state lifetimes (~700 ps and ~100 ps). More typical spectra and S1 lifetime (~2.3 ns) are found for B-3. The combined photophysical and molecular-orbital characteristics suggest the altered spectra and enhanced nonradiative S1 decay of B-1 and B-2 derive from excited-state configurations in which electron density is shifted between the macrocycle and the substituents.

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Section: Introductionmentioning

confidence: 89%

“…Three distinct classes include cyanine, styryl, and merocyanine dyes, for which representative structures are shown in Fig. 1A (1)(2)(3)(4)(5)(6)(7)(8). Key distinctions between the dyes center on the nature of the p-system and supporting hetero-organic framework, including the number of carbon atoms and the charge therein.…”

Section: Introductionmentioning

confidence: 99%

Integration of Cyanine, Merocyanine and Styryl Dye Motifs with Synthetic Bacteriochlorins

Yang

Zhang

Krayer

et al. 2015

Photochem & Photobiology

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“…The fluorescence quantum yield of the aqueous solution of 2 is 2.6%, 4 while that of 2-4-(diphenylamino)phenyl-ethenyl-1-methylpyridinium iodide (close analogue of 1 ) is about 0.03–0.05 %. 10,11…”

Section: Resultsmentioning

confidence: 99%

Ultrafast Dynamics of Electronically Excited Host–Guest Complexes of Cucurbiturils with Styryl Dyes

2019

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The relaxation mechanism of electronically excited states of host–guest complexes between cucurbiturils (CB) and pyridinium styryl dyes is considered in detail on the basis of the recent results obtained by the up-conversion fluorescence technique. The addition of CB to aqueous dye solutions increases the longest fluorescence decay times from about 50 ps for the free dyes to 100–150 ps for the bound ones. This is attributed to the braking of intramolecular rotations around the single bonds of the styryl moiety that is provided by guest’s displacement inside the cavity, whose driving force is a Coulombic interaction of the styryl dye cation and negatively charged CB portals. This displacement, a translational movement along the CB axis, is associated with the observed decay time of about 1 ps. There is also a characteristic time of about 100 fs, attributed to vibrational relaxation. In fact, such complexes can operate as a molecular machine, the molecular switch.

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“…By comparing the molecular activity of Cy c with 1-methyl-4'-(p-N,Ndimethylaminostyryl)pyridiniumiodid (M c ) in aqueous solution, one can notice that the rate constant of M c reaction (2.2x10 -4 s -1 ) is higher than the case of Cy c . Also, the activation energy (26.12 kcal/mol) and the positive value of entropy of activation (10.39 eu/mol) for M c reaction are slower than those for Cy c reaction 56 . The interaction of Cy c with water molecules is stronger than M c because its benzenoid structure has high stability as a result of its high ground state dipole moment and due to the formation hydrogen bonding by its phenoxy moiety with water molecules [61][62][63] .…”

Section: Thermal Isomerizationmentioning

confidence: 93%

“…The photochemical behavior of CyH + as it is in good agreement with those reported for similar and with other structurally related compounds like stilbene, 1,2-diphenylpropylene, 4-stilbazole and Brooker's merocyanine dye, 1-methyl-4-(4 ' -hydroxystyryl)pyridinium betaine, MH + (Table 1). 56 0.255 0.47 0.007 4-Nitro-4 ' -methoxy stilbene 57 0.07 0.48 The comparison suggests that stilbene, stilbene like-structures and CyH + have nearly the same behavior, where the Ф tc value is higher than Ф ct . By suggesting that there is analogy between 1,2-diphenylpropene, stilbene dyes and our compound cyanine dye, the photoisomerization of Cy tr H + to Cy c H + and vice versa may proceed via a phantom state X, which is a common intermediate in the radiationless deactivation of both trans and the cis excited singlet states 58 .…”

Section: Absorbancementioning

confidence: 99%

Absorption, Fluorescence, Photochemical and Thermal cis/trans Isomerization Reactivity of 1-Methyl-4-(4ʹ-aminostyryl)pyridinium Iodide

2015

Chem Sci Trans

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The photo and thermal cis/trans isomerization reactions are studied for 1-methyl-4-(4 ʹaminostyryl)pyridinium iodide, Cy, which is prepared in the trans form. In a basic solution the trans form, Cy tr , cannot isomerise directly to the cis form. Its protonated form, Cy tr H + , is active and reacts photochemically from trans to cis configuration, Cy c H +. The quantum yields Ф tc and Ф ct are determined in water. Deprotonation process of Cy c H + yields the cis isomer, Cy c , which can thermally back to the stable trans form. The rate constants and the activated parameters of the thermal reaction are determined. Due to irreversibility of the thermal reaction, a complete molecular reaction cycle is performed in one direction. To get more information on the spectral characteristics of protonated form, the photochromic of the title compound is studied in different fourteen solvents. The linear relationships between absorption energy with hydrogen bond acceptor ability of the solvents and fluorescence energy of CyH + with free energy for transferring the proton to the solvent, DG t o were determined.

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Steady-state fluorescence and photo-isomerization study of 1-methyl-4′-(p-N,N dimethyl-amino styryl) pyridinium iodide

Cited by 10 publications

References 53 publications

Integration of Cyanine, Merocyanine and Styryl Dye Motifs with Synthetic Bacteriochlorins

Integration of Cyanine, Merocyanine and Styryl Dye Motifs with Synthetic Bacteriochlorins

Ultrafast Dynamics of Electronically Excited Host–Guest Complexes of Cucurbiturils with Styryl Dyes

Absorption, Fluorescence, Photochemical and Thermal cis/trans Isomerization Reactivity of 1-Methyl-4-(4ʹ-aminostyryl)pyridinium Iodide

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