Photophysical and photochemical properties of Coumarin-6 molecules incorporated within MCM-48

Li, Dongmei; Zhang, Jinlong; Anpo, Masakazu; Xue, Minzhao; Liu, Yangang

doi:10.1016/j.matlet.2005.02.044

Cited by 14 publications

(15 citation statements)

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“…The environmental effect on fluorescence of simple or complex coumarin derivatives was extensively studied as solvent effect [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ], inside the micelles [ 19 , 20 , 21 , 22 ] and cavities [ 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 ] and polymer matrices [ 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 ]. The fluorescence of the bichromophoric coumarins is rather sensitive on the environment.…”

Section: Resultsmentioning

confidence: 99%

“…The strong solvent dependence of various coumarins was exploited for the characterization of micelles [ 19 , 20 , 21 , 22 ]. They respond spectrally respond to other cavities, such as for instance inclusion complexes [ 23 , 24 ], inside the cavities of porous materials or on its surface [ 25 , 26 ]. They are used for characterization of materials prepared by sol-gel processes [ 27 , 28 , 29 ] and also nanoparticles, e.g.…”

Section: Introductionmentioning

confidence: 99%

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Influence of Polarity of Solvents on the Spectral Properties of Bichromophoric Coumarins

et al. 2010

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Absorption and fluorescence spectra of bichromophoric coumarins were investigated in different solvents and in polymer matrices. These bichromophoric coumarins were composed of a coumarin dimethylamino-substituted at position 7 or unsubstituted coumarin and phthalimide or a 1,8-naphthylimide linked with an iminomethyl bridge to the position 3 or 8 of the coumarin ring. Absorption spectra of 7-dimethylamino derivatives in position 3 of coumarin were quite similar, exhibiting broad bands around 430-440 nm like the parent compound 7-dimethylaminocoumarin-3-carbaldehyde. For coumarin derivatives substituted in position 8, the absorption maximum was shifted to shorter wavelength as for derivatives without position 7 dimethylamino substitution. The most intense fluorescence was observed for 7-(N,N-dimethylamino)-3-[(N-phtalimidoyl)iminomethyl]coumarin in polar solvent, while intense fluorescence was observed for 7-(N,N-dimethylamino)-3-[N-(1,3-dioxobenz[de]isoquinolinyl)iminomethyl]-coumarin in non polar solvent (chloroform), comparable with the fluorescence of 7-amino-4-methylcoumarin. Spectral measurements of bichromophoric coumarins in polymer matrices revealed that the maxima lies in between those for chloroform and methanol yielding more intense fluorescence then in solutions. Completely different solvent effects were observed for 7-(N,N-dimethylamino)-3-[N-(1,3-dioxobenz[de]isoquinolinyl)imino-methyl]coumarin and 7-(N,N-dimethylamino)-3-[(N-phtalimidoyl)iminomethyl]coumarin. With addition of polar methanol the intensity of fluorescence decreases, yielding a Stern-Volmer-like constant of 0.54 dm3mol−1 for 7-(N,N-dimethylamino)-3-[N-(1,3-dioxo-benz[de]isoquinolinyl)iminomethyl]coumarin and an even higher one of 1.08 dm3mol−1 for 7-dimethylaminocoumarin-3-carbaldehyde compared to the rather low one of 0.024 dm3 mol−1 for 7-amino-4-methylcoumarin. Contrary to this, addition of methanol under identical conditions brings about an increase in fluorescence intensity of 7-(N,N-dimethylamino)-3-[(N-phtalimidoyl)iminomethyl]coumarin (about 60-fold). The reasons for these different solvent effects are discussed.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Influence of Polarity of Solvents on the Spectral Properties of Bichromophoric Coumarins

et al. 2010

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“…The strong solvent dependence of various coumarins has been exploited in the characterization of micelles [22,23,24,25]. They respond spectrally to other cavities, including inclusion complexes [26,27], within the cavities of porous materials and on their surface [28,29]. They are used in the characterization of materials prepared by sol-gel processes [30,31,32], and of nano-particles such as silica and silver [33,34].…”

Section: Introductionmentioning

confidence: 99%

Spectral Properties of Substituted Coumarins in Solution and Polymer Matrices

et al. 2012

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Abstract:The absorption and fluorescence spectra of substituted coumarins (2-oxo-2H-chromenes) were investigated in solvents and in polymer matrices. The substitutions involved were: (1) by groups with varying electron donating ability such as CH 3 , OCH 3 and N(CH 3 ) 2 , mainly, but not exclusively, in positions 7 and (2), by either CHO or 4-PhNHCONHN=CH-in position 3. While the spectra of non-substituted coumarin-3-carbaldehyde has absorptions at approximately 305 and 350 nm, substitution at position 7 leads to remarkable changes in the shape of the absorption spectrum and shifts the absorption to a longer wavelength. Similarly, the replacement of the formyl group with a semicarbazide group substantially influences the shape of the absorption spectrum, and coumarins which have only N(CH 3 ) 2 in position 7 experience small changes. These changes are associated with the increasing intramolecular charge transfer (ICT) character and increasing conjugation length of the chromophoric system, respectively, in the studied molecules. The fluorescence is almost negligible for derivatives which have H in this position. With increasing electron donating ability, and the possibility of a positive mesomeric (+M) effect of the substituent in position 7 of the coumarin moiety, the fluorescence increases, and this increase is most intense when N(CH 3 ) 2 substitutes in this position, for both 3-substituted derivatives. Spectral measurements of the studied OPEN ACCESSMolecules 2012, 17 3260 coumarins in polymer matrices revealed that the absorption and fluorescence maxima lay within the maxima for solvents, and that coumarins yield more intense fluorescence in polymer matrices than when they are in solution. The quantum yield of derivatives which have a dimethylamino group in position 7 in polymer matrices approaches 1, and the fluorescence lifetime is within the range of 0.5-4 ns. The high quantum yield of 7-dimethylamino derivatives qualifies them as laser dyes which have k F higher than k nr in the given medium. This is caused by stiffening of the coumarin structure in polar polymer matrices, such as PMMA and PVC, due to higher micro-viscosity than in solution and intermolecular dipole-dipole interaction between chromophore (dopant) and matrix.

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“…This finding is in accordance with the macroscopic observation that C6 crystals were not completely solubilized in MHS1 at these concentrations. Hence, the stagnation in fluorescence cannot be accounted to self‐quenching processes that may as well occur at elevated concentrations of fluorescent probes . Therefore, solubilization of C6 in SLN5LM30G cannot be explained by its incorporation in MHS micelles next to SLN.…”

Section: Resultsmentioning

confidence: 99%

“…Furthermore, C6 is pH‐responsive, which makes a direct pH assessment by fluorescence spectroscopy possible . C6 was versatilely applied for the characterization of, e.g., mesoporous silica , silica matrix sol–gel thin films (including energy transfer to co‐included rhodamine 6G) , zeolites , and photoresist films . In pharmaceutical development, C6 can serve as probe to determine the microenvironment of proteins , by that detect protein aggregation, and even provide information on aggregate morphology .…”

Section: Introductionmentioning

confidence: 99%

Coumarin 6 as a fluorescent model drug: How to identify properties of lipid colloidal drug delivery systems via fluorescence spectroscopy?

Finke

Richter

Gothsch

et al. 2014

Euro J Lipid Sci & Tech

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In the development of colloidal lipid drug delivery systems (DDS), the localization of the drug within the DDS, the protective potential of the DDS as well as the compatibility of the drug with the excipients are of special interest. In this study, Coumarin 6 (C6), a fluorescent dye frequently used to facilitate the traceability of DDS in vitro, is demonstrated as a tool to gain insight into the aforementioned properties by fluorescence spectroscopy. Both ways of loading C6 to solid colloidal DDS (pre‐loading to the lipid matrix or post‐loading to the ready DDS after its processing) led to a localization of C6 in the interfacial layer between solid lipid nanoparticles (SLN) and aqueous medium. In the case of pre‐loading, C6 is homogenously distributed in emulsion droplets and expelled from the lipid matrix due to crystallization. Nanoemulsions distributed C6 in the liquid lipid matrix itself and cause a hypsochromic shift of fluorescence spectra. Larger surface areas of emulsion droplets due to smaller droplet sizes displayed more interaction of C6 with the aqueous phase as a bathochromic shoulder in fluorescence spectra. Measured fluorescence intensity was linearly dependent on light scattering of colloidal DDS of the same excipients. A simple method to evaluate the protective properties of DDS was presented and displayed that (i) nanoemulsions provide more protection compared with SLN and (ii) higher phospholipid concentration improve the protection within SLN. Practical applications: In the development of colloidal DDS, it is important to identify the localization and distribution of a (model) drug in compartments within the disperse system. The simple approach by fluorescence spectroscopy presented in this study supplies information about the localization of drug substances with properties comparable with the fluorescent probe used. The results assist formulation development as a quick screening tool to elucidate (i) the localization of the probe, (ii) the microenvironment of the probe (e.g., differentiation of the physical state of the disperse phase), and (iii) the protection of the probe against damaging agents from the aqueous phase. The fluorescent dye Coumarin 6 was applied as model drug in colloidal lipid drug delivery systems. Fluorescence spectroscopy proved able to identify the localization of the model compound, the physical state of the dispersed phase, and the protective potential of the DDS, especially dependent on phospholipid concentration.

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Photophysical and photochemical properties of Coumarin-6 molecules incorporated within MCM-48

Cited by 14 publications

References 14 publications

Influence of Polarity of Solvents on the Spectral Properties of Bichromophoric Coumarins

Influence of Polarity of Solvents on the Spectral Properties of Bichromophoric Coumarins

Spectral Properties of Substituted Coumarins in Solution and Polymer Matrices

Coumarin 6 as a fluorescent model drug: How to identify properties of lipid colloidal drug delivery systems via fluorescence spectroscopy?

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