Photoluminescence of Eu(iii)-doped lamellar bridged silsesquioxanes self-templated through a hydrogen bonding array

Nobre, Sónia S.; Brites, Carlos D. S.; Ferreira, Rute A. S.; Bermúdez, V. de Zea; Carcel, Carole; Moreau, Joël J. E.; Rocha, João; Man, Michel Wong Chi; Carlos, Luís D.

doi:10.1039/b807262k

Cited by 60 publications

(82 citation statements)

References 89 publications

(112 reference statements)

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“…The condensation degrees deduced (Table S1) are on the same order of magnitude as those reported previously for the lamellar L12 material 10,12,15 and more recently for the sponge-like L12D material. 17 These findings suggest that in the C 10 C n C 10 BSs, the siloxane framework is a 2D network composed of linear polymer siloxane linkages.…”

Section: Resultssupporting

confidence: 84%

“…16 Recently, we reported that lanthanide ions may play a structuring role under the same reaction conditions employed to produce L12 and A12. 15,16 When the synthetic procedure used to prepare L12 was adopted and Eu 3+ ions were incorporated (introduced as europium chloride (EuCl 3 )) (molar ratio P12/H 2 O/HCl/EuCl 3 = 1:600:0.2:x, where x = 0.05, 0.95, and 2.9), a photoluminescent lamellar BS (Eu@L12) was formed. 15 The combination of NH 4 16 The influence of the type of solvent was emphasized more recently.…”

Section: Introductionmentioning

confidence: 99%

“…15,16 When the synthetic procedure used to prepare L12 was adopted and Eu 3+ ions were incorporated (introduced as europium chloride (EuCl 3 )) (molar ratio P12/H 2 O/HCl/EuCl 3 = 1:600:0.2:x, where x = 0.05, 0.95, and 2.9), a photoluminescent lamellar BS (Eu@L12) was formed. 15 The combination of NH 4 16 The influence of the type of solvent was emphasized more recently. 17 When the synthetic route employed to prepare L12 was combined with the incorporation of a large excess of dimethylsulfoxide (DMSO) (molar ratio P12/H 2 O/DMSO/ HCl = 1:527:388:0.175), a material with a microsphere-like shape that mimics sea sponges was produced (L12D).…”

Section: Introductionmentioning

confidence: 99%

“…Moreover, in the C 10 C n C 10 series, no aggregates II were detected. 15 The formation of aggregates IV occurs prior to that of aggregates III. Aggregates I are formed last.…”

Section: ' Conclusionmentioning

confidence: 99%

“…15 This is not surprising, considering that urea groups are known to produce impressive self-assembly effects (e.g., excellent gelling properties 48,49 ). This unusual behavior is intimately associated with the particular geometry of the urea moiety.…”

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confidence: 99%

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Self-Structuring of Lamellar Bridged Silsesquioxanes with Long Side Spacers

Fernandes

Nobre

et al. 2011

J. Phys. Chem. B

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International audienceDiurea cross-linked bridged silsesquioxanes (BSs) C10CnC10 derived from organosilane precursors, including decylene chains as side spacers and alkylene chains with variable length as central spacers (EtO)3Si (CH2)10 Y (CH2)n Y (CH2)10 Si(OEt)3 (n = 7, 9 12; Y = urea group and Et = ethyl), have been synthesized through the combination of self-directed assembly and an acid-catalyzed sol gel route involving the addition of dimethylsulfoxide (DMSO) and a large excess of water. This new family of hybrids has enabled us to conclude that the length of the side spacers plays a unique role in the structuring of alkylene-based BSs, although their morphology remains unaffected. All the samples adopt a lamellar structure. While the alkylene chains are totally disordered in the case of the C10C7C10 sample, a variable proportion of all-trans and gauche conformers exists in the materials with longer central spacers. The highest degree of structuring occurs for n = 9. The inclusion of decylene instead of propylene chains as side spacers leads to the formation of a stronger hydrogen-bonded urea urea array as evidenced by two dimensional correlation Fourier transform infrared spectroscopic analysis. The emission spectra and emission quantum yields of the C10CnC10 materials are similar to those reported for diurea cross-linked alkylene-based BSs incorporating propylene chains as side spacers and prepared under different experimental conditions. The emission of the C10CnC10 hybrids is ascribed to the overlap of two distinct components that occur within the urea cross-linkages and within the siliceous nanodomains. Time-resolved photoluminescence spectroscopy has provided evidence that the average distance between the siliceous domains and the urea cross-links is similar in the C10CnC10 BSs and in oxyethylene-based hybrid analogues incorporating propylene chains as side spacers (diureasils), an indication that the longer side chains in the former materials adopt gauche conformations. It has also allowed us to demonstrate for the first time that the emission features of the urea-related component of the emission of alkylene-based BSs depend critically on the length of the side spacers

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Section: Resultssupporting

confidence: 84%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…Moreover, in the C 10 C n C 10 series, no aggregates II were detected. 15 The formation of aggregates IV occurs prior to that of aggregates III. Aggregates I are formed last.…”

Section: ' Conclusionmentioning

confidence: 99%

mentioning

confidence: 99%

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Self-Structuring of Lamellar Bridged Silsesquioxanes with Long Side Spacers

Fernandes

Nobre

et al. 2011

J. Phys. Chem. B

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Two‐Photon‐Excited Silica and Organosilica Nanoparticles for Spatiotemporal Cancer Treatment

Croissant

Zink

Raehm

et al. 2018

Adv Healthcare Materials

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Coherent two-photon-excited (TPE) therapy in the near-infrared (NIR) provides safer cancer treatments than current therapies lacking spatial and temporal selectivities because it is characterized by a 3D spatial resolution of 1 µm and very low scattering. In this review, the principle of TPE and its significance in combination with organosilica nanoparticles (NPs) are introduced and then studies involving the design of pioneering TPE-NIR organosilica nanomaterials are discussed for bioimaging, drug delivery, and photodynamic therapy. Organosilica nanoparticles and their rich and well-established chemistry, tunable composition, porosity, size, and morphology provide ideal platforms for minimal side-effect therapies via TPE-NIR. Mesoporous silica and organosilica nanoparticles endowed with high surface areas can be functionalized to carry hydrophobic and biologically unstable two-photon absorbers for drug delivery and diagnosis. Currently, most light-actuated clinical therapeutic applications with NPs involve photodynamic therapy by singlet oxygen generation, but low photosensitizing efficiencies, tumor resistance, and lack of spatial resolution limit their applicability. On the contrary, higher photosensitizing yields, versatile therapies, and a unique spatial resolution are available with engineered two-photon-sensitive organosilica particles that selectively impact tumors while healthy tissues remain untouched. Patients suffering pathologies such as retinoblastoma, breast, and skin cancers will greatly benefit from TPE-NIR ultrasensitive diagnosis and therapy.

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Lanthanide‐Containing Light‐Emitting Organic–Inorganic Hybrids: A Bet on the Future

et al. 2009

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Interest in lanthanide-containing organic-inorganic hybrids has grown considerably during the last decade, with the concomitant fabrication of materials with tunable attributes offering modulated properties. The potential of these materials relies on exploiting the synergy between the intrinsic characteristics of sol-gel derived hosts (highly controlled purity, versatile shaping and patterning, excellent optical quality, easy control of the refractive index, photosensitivity, encapsulation of large amounts of isolated emitting centers protected by the host) and the luminescence features of trivalent lanthanide ions (high luminescence quantum yield, narrow bandwidth, long-lived emission, large Stokes shifts, ligand-dependent luminescence sensitization). Promising applications may be envisaged, such as light-emitting devices, active waveguides in the visible and near-IR spectral regions, active coatings, and bio-medical actuators and sensors, opening up exciting directions in materials science and related technologies with significant implications in the integration, miniaturization, and multifunctionalization of devices. This review provides an overview of the latest advances in Ln(3+)-containing siloxane-based hybrids, with emphasis on the different possible synthetic strategies, photoluminescence features, empirical determination.

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Photoluminescence of Eu(iii)-doped lamellar bridged silsesquioxanes self-templated through a hydrogen bonding array

Cited by 60 publications

References 89 publications

Self-Structuring of Lamellar Bridged Silsesquioxanes with Long Side Spacers

Self-Structuring of Lamellar Bridged Silsesquioxanes with Long Side Spacers

Two‐Photon‐Excited Silica and Organosilica Nanoparticles for Spatiotemporal Cancer Treatment

Lanthanide‐Containing Light‐Emitting Organic–Inorganic Hybrids: A Bet on the Future

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