Photoactive Nanomaterials Inspired by Nature: LTL Zeolite Doped with Laser Dyes as Artificial Light Harvesting Systems

The herein reported work describes the development of hierarchically-organized fluorescent nanomaterials inspired by plant antenna systems. These hybrid materials are based on nanostructured zeolitic materials (LTL zeolite) doped with laser dyes, which implies a synergism between organic and inorganic moieties. The non-interconnected channeled structure and pore dimensions (7.1 angstrom) of the inorganic host are ideal to order and align the allocated fluorophores inside, inferring also high thermal and chemical stability. These artificial antennae harvest a broad range of chromatic radiation and convert it into predominant red-edge or alternatively white-light emission, just choosing the right dye combination and concentration ratio to modulate the efficiency of the ongoing energy transfer hops. A further degree of organization can be achieved by functionalizing the channel entrances of LTL zeolite with specific tailor-made (stopcock) molecules via a covalent linkage. These molecules plug the channels to avoid the leakage of the guest molecules absorbed inside, as well as connect the inner space of the zeolite with the outside thanks to energy transfer processes, making the coupling of the material with external devices easier.This work was supported by the Basque Government (IT912-16) and Spanish MICINN (MAT2014-51937-C3-3-P) projects. Leire Gartzia also thanks the Basque Goberment for a Post-doctoral grant. Yi Xiao from Dalian University (China) is kindly acknowledged for the supply and synthesis of the stopcock molecule

Water Adsorption on the β-Dicalcium Silicate Surface from DFT Simulations

beta-dicalcium silicate (beta-Ca2SiO4 or beta-C2S in cement chemistry notation) is one of the most important minerals in cement. An improvement of its hydration rate would be the key point for developing environmentally-friendly cements with lower energy consumption and CO2 emissions. However, there is a lack of fundamental understanding on the water/beta-C2S surface interactions. In this work, we aim to evaluate the water adsorption on three beta-C2S surfaces at the atomic scale using density functional theory (DFT) calculations. Our results indicate that thermodynamically favorable water adsorption takes place in several surface sites with a broad range of adsorption energies (-0.78 to -1.48 eV) depending on the particular mineral surface and adsorption site. To clarify the key factor governing the adsorption of the electronic properties of water at the surface were analyzed. The partial density of states (DOS), charge analysis, and electron density difference analyses suggest a dual interaction of water with a beta-C2S (100) surface including a nucleophilic interaction of the water oxygen lone pair with surface calcium atoms and an electrophilic interaction (hydrogen bond) of one water hydrogen with surface oxygen atoms. Despite the elucidation of the adsorption mechanism, no correlation was found between the electronic structure and the adsorption energies.National Natural Science Foundation of China (No. 51602148), the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD), the Program for Innovative Research Team in the University of Ministry of Education of China (No. IRT_15R35), the financial support from the Departamento de Educacion, Politica Linguistica y Cultura del Gobierno Vasco (IT912-16) and the ELKARTEK project

Ready Access to Molecular Rotors Based on Boron Dipyrromethene Dyes-Coumarin Dyads Featuring Broadband Absorption

Herein we report on a straightforward access method for boron dipyrromethene dyes (BODIPYs)-coumarin hybrids linked through their respective 8- and 6- positions, with wide functionalization of the coumarin fragment, using salicylaldehyde as a versatile building block. The computationally-assisted photophysical study unveils broadband absorption upon proper functionalization of the coumarin, as well as the key role of the conformational freedom of the coumarin appended at the meso position of the BODIPY. Such free motion almost suppresses the fluorescence signal, but enables us to apply these dyads as molecular rotors to monitor the surrounding microviscosity.This research was funded by Spanish Ministerio de Economia y Competitividad (project MAT2017-83856-C3-3-P), Gobierno Vasco (project IT912-16), CONACyT (grants 253623, 123732) and Dirección de Apoyo a la Investigación (DAIP-UG CIIC318/2019)

Functionalized Fluorescent Silica Nanoparticles for Bioimaging of Cancer Cells

Functionalized fluorescent silica nanoparticles were designed and synthesized to selectively target cancer cells for bioimaging analysis. The synthesis method and characterization of functionalized fluorescent silica nanoparticles (50–60 nm), as well as internalization and subcellular localization in HeLa cells is reported here. The dye, rhodamine 101 (R101) was physically embedded during the sol–gel synthesis. The dye loading was optimized by varying the synthesis conditions (temperature and dye concentration added to the gel) and by the use of different organotriethoxysilanes as a second silica precursor. Additionally, R101, was also covalently bound to the functionalized external surface of the silica nanoparticles. The quantum yields of the dye-doped silica nanoparticles range from 0.25 to 0.50 and demonstrated an enhanced brightness of 230–260 fold respect to the free dye in solution. The shell of the nanoparticles was further decorated with PEG of 2000 Da and folic acid (FA) to ensure good stability in water and to enhance selectivity to cancer cells, respectively. In vitro assays with HeLa cells showed that fluorescent nanoparticles were internalized by cells accumulating exclusively into lysosomes. Quantitative analysis showed a significantly higher accumulation of FA functionalized fluorescent silica nanoparticles compared to nanoparticles without FA, proving that the former may represent good candidates for targeting cancer cells.This research was funded by the Basque Government, grant numbers IT912-16 and IT-1302-19; Ministry of Economy and Competitiveness (MINECO), grant numbers MAT2017-83856-C3-3-P and CTM2016-81130-R; and the University of the Basque Country (UPV/EHU), grant number COLAB19/01

One-Directional Antenna Systems: Energy Transfer from Monomers to JAggregates within 1D Nanoporous Aluminophosphates

A cyanine dye (PIC) was occluded into two 1D-nanopoporus Mg-containing aluminophosphates with different pore size (MgAPO-5 and MgAPO-36 with AFI and ATS zeolitic structure types, with cylindrical channels of 7.3 Å diameter and elliptical channels of 6.7 Å × 7.5 Å, respectively) by crystallization inclusion method. Different J-aggregates are photophysically characterized as a consequence of the different pore size of the MgAPO frameworks, with emission bands at 565 nm and at 610 nm in MgAPO-5 and MgAPO-36, respectively. Computational results indicate a more linear geometry of the J-aggregates inside the nanochannels of the MgAPO-36 sample than those in MgAPO-5, which is as a consequence of the more constrained environment in the former. For the same reason, the fluorescence of the PIC monomers at 550 nm is also activated within the MgAPO-36 channels. Owing to the strategic distribution of the fluorescent PIC species in MgAPO-36 crystals (monomers at one edge and J-aggregates with intriguing emission properties at the other edge) an efficient and one-directional antenna system is obtained. The unidirectional energy transfer process from monomers to J-aggregates is demonstrated by remote excitation experiments along tens of microns of distance.Financial support from Gobierno Vasco (IT912-16) and Ministerio de Economía y Competitividad “MINECO” (through Projects MAT2014-51937-C3-3-P, MAT2016-77496-R and MAT-2015-65767-P) is acknowledged. R.S.L. and V.M.M. acknowledge niversidad del PaísVasco (UPV-EHU) for a postdoctoral fellowship and MINECO for a “Ramón y Cajal” Contract RYC-2011-09505), respectively. H.U. gratefully acknowledges the financial support of the European Research Council (#280064), the FWO (G056314N, G0B5514N, G081916N), and JSPS KAKENHI (JP17H03003, JP17H05244, JP17H05458). Centro Técnico de Informática (CSIC) is acknowledged for running the calculations and Accelrys for providing the computational softwar

Unprecedented J-Aggregated Dyes in Pure Organic Solvents

We describe the design and synthesis of the first organic dyes enabling spontaneous formation of stable J-aggregates in common organic solvents without additives. The new dyes are O-BODIPYs with a B-spiranic 4,4-diacyloxyl substitution pattern. Key to the effectiveness of the J-aggregation process is the high conformational rigidity of the Bspiranic molecular design as well as the orthogonal disposition of the B-diacyloxyl substituent and the meso-aryl group with respect to the mean plane of the borodiazaindacene. Atomistic simulations, both in vacuum and in a solvent cage, support the dynamics of the J-aggregation process as well as its dependence on the alkylation pattern of the BODIPY chromophore. A detailed analysis of the photophysical and laser properties of the new dyes provides convincing evidence for the unambiguous assignment of these J-aggregates and their dependence on the environmental conditions.We gratefully acknowledge financial support by the Spanish Ministerio de Economia y Competitividad (projects MAT2014-51937-C3-1-P, MAT2014- 51937-C3-2-P, MAT2014-51937-C3-3-P, and MAT2015-68837-REDT). I. E. thanks the Gobierno Vasco (IT339-10) for a predoctoral contract. H. M. acknowledges the Spanish Ministerio de Economia y Competitividad for a Juan de la Cierva postdoctoral contract. The authors thank SGIker of UPV/EHU for technical and human support with the X-ray diffraction measurements and computational calculations, which were carried out in the “arina” informatic cluster. We also thank Diego Plaza Lozano for preliminary synthetic studies.Peer reviewe

Red-edge-wavelength finely-tunable laser action from new BODIPY dyes

8 páginas, 6 figuras, 2 tablas.-- et al.New BODIPY dyes with two 4-formylphenyl, 4-(2,2-dimethoxycarbonylvinyl)phenyl and 4-(2,2-dicyanovinyl)phenyl groups at the 3- and 5-positions have been successfully designed and synthesized via palladium-catalyzed coupling reaction or Knoevenagel-type condensations. Structural modification of the BODIPY core via conjugation-extending residues significantly affects the spectroscopy and photophysical properties of the BODIPY fluorophore. These substituents cause the largest bathochromic shift in both absorption and emission spectra, which are shifted toward the red compared to its 4-phenylsubstituted analogue. Additionally, the fluorescence quantum yields and the Stokes shifts are also significantly higher than the corresponding phenyl-substituted dye. New BODIPY dyes have a high laser photostability, superior to that of commercial dyes with laser emission in the same spectral region, such as Perylene Red and Rhodamine 640. The substitution introduced in these derivatives allows to obtain tunable laser emission with a bandwidth of 0.15 cm−1 and a tuning range of up to 50 nm. So with these three dyes it is possible to cover the spectral range 590–680 nm in a continuous way and with stable laser emission and small linewidth.This research was financed by the Spanish MICINN (Project MAT2007-65778-C02-01 and -02 and Project CTQ2008-02820) and Universidad Complutense of Madrid (Project GR58/08).Peer reviewe

Nitro and amino BODIPYS: crucial substituents to modulate their photonic behavior

The present work deals with the synthesis and photophysical, quantum mechanical, and lasing characterization of novel BODIPYs bearing amino and nitro groups at different positions in the core. The results emphasize the relevant role on the photophysical and lasing properties, not only of the attached functionality but also of the position in which is grafted, as well as the molecular structure of the indacene core. A wide part of the visible spectrum can be covered by the insertion of an amino group at position 3 (red shift) or 8 (blue shift). Furthermore, the electron withdrawing character of the nitro substituent induces intramolecular charge transfer processes, the efficiency of which depends on the position of the nitro group on the BODIPY core. All these experimental findings can be rationalized with the help of quantum mechanical calculations.Peer Reviewe

The carnitine shuttle: an untapped transporter for mitochondrial imaging

33° Congreso Latinoamericano de Química. X Congreso de Ciencias, Tecnología e Innovación Química. 9 al 12 de Octubre del 2018 en el Palacio de Convenciones de La Habana, Cuba. .-http://www.chemistrycuba.com/es/general_infoCellular metabolism is enhanced in cancer in order to sustain cell viability and uncontrolled proliferation. In particular, deregulation of lipid metabolism is one of the most important metabolic hallmarks of cancer cells. The carnitine shuttle system (CS), involved in the transport of fatty acids from the cytosol into the mitochondria matrix for oxidation, represents a major bottleneck for lipid metabolism and its reprogramming can play a pivotal role in tumors, suggesting new pathways for prevention and treatment

Shedding Light on the Mitochondrial Matrix Through a Functional Membrane Transporter

Electronic Supplementary Information (ESI) available: Supplementary figures and tables and copies of the 1H and 13C NMR (1D and 2D) spectra of the new compounds.The first fluorescent probes that are actively channeled into the mitochondrial matrix by a specific mitochondrial membrane transporter in living cells have been developed. The new functional probes (BCT) have a minimalist structural design based on the highly efficient and photostable BODIPY chromophore and carnitine as a biotargeting element. Both units are orthogonally bonded through the common boron atom, thus avoiding the use of complex polyatomic connectors. In contrast to known mitochondria-specific dyes, BCTs selectively label these organelles regardless of their transmembrane potential and in an enantioselective way. The obtained experimental evidence supports carnitine-acylcarnitine translocase (CACT) as the key transporter protein for BCTs, which behave therefore as acylcarnitine biomimetics. This simple structural design can be readily extended to other structurally diverse starting FBODIPYs to obtain BCTs with varied emission wavelengths along the visible and NIR spectral regions and with multifunctional capabilities. BCTs are the first fluorescent derivatives of carnitine to be used in cell microscopy and stand as promising research tools to explore the role of the carnitine shuttle system in cancer and metabolic diseases. Extension of this approach to other small-molecule mitochondrial transporters is envisaged.We gratefully acknowledge the Spanish Ministerio de Ciencia, Innovación y Universidades (MCIU), Agencia Estatal de Investigación (AEI), and European Regional Development Fund (ERDF) (projects MAT2017-83856-C3-1-P, MAT2017-83856-C3-3-P, and MAT2015-68837-REDT), Gobierno Vasco (IT912-16), and the Instituto de Salud Carlos III-Fondo de Investigación Sanitaria (CIBERONC and PI17/01901) for financial support. A. B.-M. and R. P. M. thank MCIU, AEI and ERDF, and UPV-EHU for a FPI predoctoral contract and predoctoral fellowship, respectivelyPeer reviewe