Mimicking the antenna system of green plants

Calzaferri, Gion; Lutkouskaya, Katsiaryna

doi:10.1039/b804682b

Cited by 153 publications

(156 citation statements)

References 119 publications

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“…The first of the mechanisms that we will discuss now is self- absorption, a process that can be easily underestimated in such composites, as has been pointed out previously and that we now explore in more detail. 15,27 The change induced by self-absorption, or inner filter effect, on the shape and intensity of luminescence spectra at high optical density is well-known. It is caused by reabsorption of the short wavelength photons emitted from a fluorophore by neighboring molecules of the same type, resulting in a red shift of the observed emission.…”

Section: −48mentioning

confidence: 99%

Self-Absorption and Luminescence Quantum Yields of Dye-Zeolite L Composites

et al. 2013

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Electronic absorption and fluorescence spectra based on transmission measurements of thin layers obtained from new perylene−zeolite L composites and new dye1,dye2−zeolite L sandwich composites, the latter acting as antenna systems, have been investigated and analyzed. The influence of extra-and intraparticle self-absorption on the spectral shape and fluorescence quantum yield is discussed in detail. Due to its intraparticle origin, self-absorption and re-emission can often not be avoided in organized systems such as dye−zeolite L composites where a high density of chromophores is a prerequisite for obtaining the desired photophysical properties. We show, however, that it can be avoided or at least minimized by preparing dye1,dye2−zeolite L sandwich composites where donors are present in a much larger amount than the acceptors because they act as antenna systems. ■ INTRODUCTIONComposites synthesized by embedding molecules, complexes, and clusters into the one-dimensional channels of zeolite L (ZL) 1,2 have recently experienced increasing interest from scientists engaged in different fields, ranging from very stable nontoxic pigments to novel optical materials with a large variety of different properties to promising objects for utilization in analytics, biology, diagnostics and drug delivery. This trend is exemplified by publications that appeared in 2013. 3−16 Electronic absorption and luminescence spectroscopy are important tools for characterizing the host−guest composites, and luminescence is often one of their key properties. Confocal luminescence microscopy on individual crystals has successfully been used and has contributed much to our current understanding of various dye−ZL properties. 17−23 It is very often desirable to measure absorption and luminescence spectra of an ensemble in order to unambiguously interpret the observations and sometimes to derive luminescence quantum yields. Diffuse reflectance spectroscopy has frequently been used in the case for which this sophisticated instrumentation has been developed. 10,24 Advancing dye−ZL research requires measurements that not only yield spectra and quantum yields as numbers but also provide information useful for understanding the mechanisms behind the observed phenomena. A prerequisite for these are high quality absorption and luminescence spectra where the band shapes can be interpreted unambiguously. This is best guaranteed if high quality transmission spectra are available. We have therefore successfully applied refractive index matching techniques in order to reduce or in favorable cases eliminate light scattering. We have used dispersions in liquid solvents or polymers as matrixes for dye−ZL composites, where sometimes a surface modification of the ZL crystals was required.25−27 More recently, a method for the preparation of thin oil−glass sandwiches (OGS) from dye−ZL composites has been employed. 15,20 This technique has proven to be very convenient and allows differentiating between mechanisms that affect the shape of the absorptio...

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Section: −48mentioning

confidence: 99%

Self-Absorption and Luminescence Quantum Yields of Dye-Zeolite L Composites

et al. 2013

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“…1 The regular pore systems of nanometric openings exhibited by the framework make zeolites ideal host matrices for achieving supramolecular organization of photoactive species, leading to versatile building blocks for the realization of hierarchically organized multifunctional composite materials. 1,2,3 Microlasers, pigments, optical switches, or artificial antenna systems are only few of the possible applications of these fascinating systems. 4,5,6,7,8,9,10 To date, different zeolites with suitable channel dimensions, such as AlPO4-5, 11,12 zeolite Y, 13 zeolite L, 14,15 as well as mesoporous materials like MCM-41, 16 have been successfully adopted as nanosized host matrices for the synthesis of these composites.…”

Section: Introductionmentioning

confidence: 99%

“…In such conditions, it becomes extremely difficult to predict the structural details of the supramolecular arrangement inside ZL simply on the basis of the geometrical parameters of the guest molecules. 2,3 Experimental information might be gathered by structural X-ray diffraction studies. However, in the case of dye-ZL systems, difficulties arise from the high symmetry of the zeolite, from the low amount of the light atoms of the dye (which do not allow the determination of a possible symmetry lowering) and from the non-coincidence of the point symmetry of ZL with that of the dye.…”

Section: Introductionmentioning

confidence: 99%

Close-Packed Dye Molecules in Zeolite Channels Self-Assemble into Supramolecular Nanoladders

et al. 2014

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A tough challenge in nanomaterials chemistry is the determination of the structure of multicomponent nanosystems. Dye-zeolite L composites are building blocks of hierarchically organized multifunctional materials for technological applications. Supramolecular organization inside zeolite L nanochannels, which governs electronic properties, is barely understood. This is especially true for confined close-packed dye molecules, a regime not investigated in applications yet and that might have great potential for future development in this field. Here we realize for the first time composites of zeolite L with maximally-packed fluorenone molecules and elucidate their structure by integrated multi-technique analyses. By IR, thermogravimetric and X-ray diffraction we establish the maximum degree of dye loading obtained (1.5 molecules per unit cell) and by modeling we reveal that at these conditions fluorenone molecules form quasi 1-D supramolecular nanoladders running along the zeolite channels. Spatial and morphological control provided by the nanoporous matrix combined with a complex blend of strong dye-zeolite and weaker dye-dye van der Walls interactions lie at the origin of this unique architecture, which is also stabilized by the hydrogen bond network of co-adsorbed water molecules surrounding the dye nanoladder and penetrating between its rungs.

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“…[44,45] Great success has been achieved on the control of hierarchical pore structure, size, and morphology of zeolite products [43,46,47] yet relatively less progress has been made on the alignment of the nanoor micro-zeolites into uniformly oriented and/or highly ordered arrays. [48] Xia et al [49] reported the first synthesis of 3D ordered arrays of nanozeolites with uniform size and crystallographic orientation, and adjustable overall shape by a simple hydrothermal coupled dissolution-reprecipitation pseudomorphic replacement route (Fig. 7).…”

Section: Transformation Of Leucite (Kalsi 2 O 6 ) To Analcite (Naalsimentioning

confidence: 99%

A Novel Route for the Synthesis of Mesoporous and Low-Thermal Stability Materials by Coupled Dissolution-Reprecipitation Reactions: Mimicking Hydrothermal Mineral Formation

Brugger

McFadden

Lenehan

et al. 2010

Chimia

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Replacement reactions ('pseudomorphism') commonly occur in Nature under a large range of conditions (T 25 to >600 ˚C; P 1 to >5 kbar). Whilst mineral replacement reactions are often assumed to proceed by solid-state diffusion of the metal ions through the mineral, many actually proceed via a coupled dissolution and reprecipitation (CDR) mechanism. In such cases, a starting mineral is dissolved into a fluid and this dissolution is coupled with the precipitation of a replacement phase across the reaction front. In cases where there are close relationships between the crystal structures of the parent and newly formed minerals, the replacement can be topotactic (interface-coupled dissolution and reprecipitation). The kinetics and chemistry of the CDR route are fundamentally different from solid-state diffusion and can be exploited i) for the synthesis of materials that are often difficult to synthesise via traditional methods and ii) to obtain materials with unique properties. This review highlights recent research into the use of CDR for such synthetic challenges. Emphasis has been given to i) the use of CDR to synthesise compounds with relatively low thermal stability such as the thiospinel mineral violarite ((Ni,Fe) 3 S 4 ), ii) preliminary work into use of CDR for the production of roquesite (CuInS 2 ), a potentially important photovoltaic component and, iii) examples where the textures resulting from CDR reactions are controlled by the nature and texture of the parent phase and the reaction conditions; these being the formation of micro-porous gold and three-dimensional ordered arrays of nanozeolite of uniform size and crystallographic orientation.

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Mimicking the antenna system of green plants

Cited by 153 publications

References 119 publications

Self-Absorption and Luminescence Quantum Yields of Dye-Zeolite L Composites

Self-Absorption and Luminescence Quantum Yields of Dye-Zeolite L Composites

Close-Packed Dye Molecules in Zeolite Channels Self-Assemble into Supramolecular Nanoladders

A Novel Route for the Synthesis of Mesoporous and Low-Thermal Stability Materials by Coupled Dissolution-Reprecipitation Reactions: Mimicking Hydrothermal Mineral Formation

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