Confinement effect of nanocages and nanotubes of mesoporous materials on the keto forms photodynamics of Sudan I

Gil, Michał; Organero, Juan Ángel; Peris, Encarna; Garcı́a, Hermenegildo; Douhal, Abderrazzak

doi:10.1016/j.cplett.2009.05.002

Cited by 20 publications

(32 citation statements)

References 45 publications

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“…The ICT rate constant (10 −13 –10 −8 s) thoroughly depends on the polarity of the medium. Numerous works have demonstrated the impact of the cavity/pore size of silica-based materials on the ICT reaction dynamics of the encapsulated guests [3,16,17,18,19,20,21,22,23,24].…”

Section: Introductionmentioning

confidence: 99%

Confinement Effect of Micro- and Mesoporous Materials on the Spectroscopy and Dynamics of a Stilbene Derivative Dye

Nunzio

Perenlei

Douhal

2019

IJMS

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Micro- and mesoporous silica-based materials are a class of porous supports that can encapsulate different guest molecules. The formation of these hybrid complexes can be associated with significant alteration of the physico-chemical properties of the guests. Here, we report on a photodynamical study of a push–pull molecule, trans-4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM), entrapped within faujasite-type zeolites (HY, NaX, and NaY) and MCM-41 in dichloromethane suspensions. The complex formation gives rise to caged monomers and H- and J-aggregates. Steady-state experiments show that the nanoconfinement provokes net blue shifts of both the absorption and emission spectra, which arise from preferential formation of H-aggregates concomitant with a distortion and/or protonation of the DCM structure. The photodynamics of the hybrid complexes are investigated by nano- to picosecond time-resolved emission experiments. The obtained fluorescence lifetimes are 65–99 ps and 350–400 ps for H- and J-aggregates, respectively, while those of monomers are 2.46–3.87 ns. Evidences for the presence of a charge-transfer (CT) process in trapped DCM molecules (monomers and/or aggregates) are observed. The obtained results are of interest in the interpretation of electron-transfer processes, twisting motions of analogues push–pull systems in confined media and understanding photocatalytic mechanisms using this type of host materials.

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Section: Introductionmentioning

confidence: 99%

Confinement Effect of Micro- and Mesoporous Materials on the Spectroscopy and Dynamics of a Stilbene Derivative Dye

Nunzio

Perenlei

Douhal

2019

IJMS

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“…[23,24] Thus, the structural features and the physicochemical properties of zeolites can be monitored by the use of specific guest molecules acting as probes through steady-state and transient spectroscopy, in addition to other techniques. In this regard, several studies have demonstrated that the photobehaviours of several encapsulated molecules, such as salicylaldehyde azine (SAA), 1-phenylazo-2-naphthol (Sudan I), 2-(2hydroxyphenyl)benzoxazole (HBO), or (E)-2-(2-hydroxybenzyliden)amino-4nitrophenol (HBA-4NP), [25][26][27][28][29][30] are largely affected by the composition and structure of the host zeolite.…”

Section: Introductionmentioning

confidence: 99%

Femto-to nanosecond photodynamics of Nile Red in metal-ion exchanged faujasites

Nunzio

Caballero-Mancebo

Martín

et al. 2018

Microporous and Mesoporous Materials

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“…The smaller pore sizes of the zeolites and the presence of a counterion screening effect in their channels also reduce the loading capacity of these materials compared to SBA-15, MCM-41, and Al-MCM-41 (Table 1). In fact, NaX presents small pore size (13 Å) and the highest amount of Na + [40,41], which leads to only 41% of CLZ to be loaded, while NaY (13 Å) has a reduced Na + amount, which allows up to 51% of CLZ to be loaded. For HY, the combination of the H + screening effect and the smallest pore size (7.4 Å) only allows for 46% of CLZ to be loaded.…”

Section: Resultsmentioning

confidence: 99%

Single Crystal FLIM Characterization of Clofazimine Loaded in Silica-Based Mesoporous Materials and Zeolites

Angiolini

Cohen

Douhal

2019

IJMS

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Clofazimine (CLZ) is an effective antibiotic used against a wide spectrum of Gram-positive bacteria and leprosy. One of its main drawbacks is its poor solubility in water. Silica based materials are used as drug delivery carriers that can increase the solubility of different hydrophobic drugs. Here, we studied how the properties of the silica framework of the mesoporous materials SBA-15, MCM-41, Al-MCM-41, and zeolites NaX, NaY, and HY affect the loading, stability, and distribution of encapsulated CLZ. Time-correlated single-photon counting (TCSPC) and fluorescence lifetime imaging microscopy (FLIM) experiments show the presence of neutral and protonated CLZ (1.3–3.8 ns) and weakly interacting aggregates (0.4–0.9 ns), along with H- and J-type aggregates (<0.1 ns). For the mesoporous and HY zeolite composites, the relative contribution to the overall emission spectra from H-type aggregates is low (<10%), while for the J-type aggregates it becomes higher (~30%). For NaX and NaY the former increased whereas the latter decreased. Although the CLZ@mesoporous composites show higher loading compared to the CLZ@zeolites ones, the behavior of CLZ is not uniform and its dynamics are more heterogeneous across different single mesoporous particles. These results may have implication in the design of silica-based drug carriers for better loading and release mechanisms of hydrophobic drugs.

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Confinement effect of nanocages and nanotubes of mesoporous materials on the keto forms photodynamics of Sudan I

Cited by 20 publications

References 45 publications

Confinement Effect of Micro- and Mesoporous Materials on the Spectroscopy and Dynamics of a Stilbene Derivative Dye

Confinement Effect of Micro- and Mesoporous Materials on the Spectroscopy and Dynamics of a Stilbene Derivative Dye

Femto-to nanosecond photodynamics of Nile Red in metal-ion exchanged faujasites

Single Crystal FLIM Characterization of Clofazimine Loaded in Silica-Based Mesoporous Materials and Zeolites

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