8-PropargylaminoBODIPY: unprecedented blue-emitting pyrromethene dye. Synthesis, photophysics and laser properties

Highly emitting 8-propargylaminoBODIPY (8-PAB) 2 was prepared in 94% yield. Unlike any other BODIPY structure hitherto described in the literature, 2 displays efficient emission in the blue region of the visible spectrum with a fluorescence quantum yield up to 0.94 and high laser efficiency (35%) at 483 nm.Grants GTO-2007-C02-69094 (CONCyTEG) (Mexico), MAT2007-65778-C02-01 and -02 of the Spanish MICINN are gratefully acknowledged. V. Martin thanks CSIC for her JAE-postdoctoral contract.Peer reviewe

Bichromatic laser emission from dipyrromethene dyes incorporated into solid polymeric media

9 pages, 9 figures.Bichromatic laser emission from dipyrromethene-based solid-state dye lasers is reported. The dependence of this dual emission on different factors and its origin and causes are discussed in the light of different models proposed in the literature. Our experimental results indicate that the long-wavelength emission can be explained in terms of reabsorption/reemission effects and inhomogeneous broadening of the S0-S1 transition. The short-wavelength emission corresponds to the usual S0-S1 transition and dominates at low dye concentration.This work was supported by Project Nos. MAT2004-04643-C03-01 and MAT2004-04643-C03-02 of the Spanish CICYT. One of the authors (M.Á.) thanks Ministerio de Ciencia y Tecnología (MCT) for a predoctoral grant. Another author (M.L.) thanks Comunidad Autónoma de Madrid for a postdoctoral grant and MCT for a Juan de la Cierva contract.Peer reviewe

A combination of proton spin diffusion NMR and molecular simulations to probe supramolecular assemblies of organic molecules in nanoporous materials

[EN] In this work we show the use of high-resolution H-1 MAS NMR to distinguish between two kinds of aggregation states of (1R,2S)-ephedrine, a chiral organic structure directing agent, occluded within AFI-type microporous aluminophosphates. We investigate in particular the supramolecular assembly of the molecules through pi MIDLINE HORIZONTAL ELLIPSIS pi type interactions of their aromatic rings when confined within the one-dimensional AFI channels. A series of high-resolution two-dimensional spin diffusion spectra combined with molecular simulations and DFT calculations allowed us to distinguish different aggregation states of ephedrine molecules and precisely estimate the distances between the aromatic rings and their closest protons inside the zeolite channels as a consequence of distinct proton spin diffusion profiles.This work has been financed by the Spanish State Research Agency (Agencia Espanola de Investigacion, AEI) through the project PID2019-107968RB-I00. BBM acknowledges the Spanish Ministry of Economy and Competitivity for a predoctoral (BES-2013-064605) contract. Secretaria General Adjunta de Informatica-CSIC is acknowledged for running the calculations, and BIOVIA for providing the computational software. We acknowledge the support of the Label of Excellence for the Centre for zeolites and nanoporous materials by the Region of Normandy (CLEAR). We acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI)

Photophysical and laser emission studies of 8-polyphenylene-substituted BODIPY dyes in liquid solution and in solid polymeric matrices

In our search for efficient and photostable laser dyes, four new dyes with the basic structure of the commercial BODIPY laser dye PM567, with either an 8-diphenylene or an 8-p-triphenylene group, both substituted at the terminal polyphenylene position with an acetoxymethyl (dyes P2Ar1Ac and P3Ar1Ac, respectively) or a methacryloyloxymethyl group (dyes P2Ar1MA and P3Ar1MA, respectively), have been synthesized. The photophysical and lasing properties of the dyes have been studied both dissolved in liquid solvents (acetoxymethyl dyes) and incorporated into solid polymeric matrices, in the latter case as solutions (acetoxymethyl dyes) or as copolymers with methyl methacrylate (methacryloyloxymethyl dyes). In liquid solution, the photophysics of P2Ar1Ac and P3Ar1Ac is scarcely affected by the number (two or three) of p-phenylene units. Quantum mechanical calculations reveal that the p-phenylene units in these dyes are twisted ca. 37◦ each other, an that the first 8-p-phenylene group stands nearly perpendicular to the aromatic BODIPY plane, resulting in electronic decoupling of the two chromophores. P2Ar1Ac exhibits a somewhat lower photodegradation quantum yield under UV and visible irradiation, if compared with P3Ar1Ac or with PM567, likely because of its also lower rate constant for the reaction with in situ-generated singlet molecular oxygen. Both acetoxymethyl dyes emit laser radiation in solution in all the solvents tried, under transversal pumping at 532 nm. In ethyl acetate, with a dye concentration of 0.80 × 10−3 M, laser efficiencies as high as 80% have been observed. When the 8-polyphenylene dyes were incorporated into solid poly(methyl methacrylate) (PMMA) matrices, as solutions or as copolymers, the fluorescence emission increased with respect to that of the parent PM567 dye dissolved in the same matrix, and lasing efficiencies in the range 18–31% were obtained, with good photostability. The dye P2Ar1Ac dissolved in PMMA was found to exhibit the best overall laser behavior, with a good balance between efficiency and photostability.This work was supported by Project MAT2004-04643-C03-01 of the Spanish CICYT. M. Liras thanks Comunidad Aut´onoma de Madrid for a predoctoral scholarship and Ministerio de Educaci´on y Ciencia for a Juan de la Cierva contract.M. A´ lvarez thanks Ministerio de Educaci´on y Ciencia for a predoctoral scholarship. The 8-polyphenylene-substituted boron-dipyrromethene dyes described in this paper and their utilization in liquid and solidstate dye lasers are covered by Spanish PatentNo. P200701763 filed on 25 June 2007.Peer reviewe

Naphthyl-Containing Organophosphonate Derivatives of Keggin-Type Polyoxotungstates

New organophosphonate derivatives of monovacant Keggin-type polyoxotungstates that contain naphthyl groups have been synthesized and characterized in both solid state and solution. Single-crystal structural analysis shows that two phosphonate groups occupy the vacant position of the lacunary cluster unit in the isostructural compounds [N(C4H9)(4)](3)[H(POC11H9)(2)(-HBW11O39)] (TBA-1) and [N(C4H9)(4)](3)[H(POC11H9)(2)(-SiW11O39)] (TBA-2). Liquid-solution UV-Vis transmittance and solid-state diffuse reflectance spectroscopy studies reveal the presence of a new absorption band in the visible region, the charge transfer character of which has been further confirmed by time-dependent density functional theory (TD-DFT) calculations. The latter evidence that the charge transfer process is dominated by transitions from the highest occupied molecular orbital (HOMO), localized in the aromatic ring of the organic group, to the lowest unoccupied molecular orbital (LUMO), localized in the Keggin anion. Photoluminescence studies show that the fluorescent properties of the 1-naphthylmethylphosphonate group are quenched upon its incorporation into the inorganic oxo-tungstate skeleton. The solution stability of the hybrid clusters has been evaluated by a combination of H-1-, C-13- and P-31-Nuclear Magnetic Resonance spectroscopy and Electrospray Ionization-Mass Spectrometry. The hybrid polyanion [H(POC11H9)(2)(-HBW11O39)](3-) (1) herein constitutes the first structurally characterized organo-p-block containing borotungstate, and hence it confirms that this strategy for the organic functionalization of polyoxometalate clusters can be applied to new platforms belonging to the family of group-13 heteropolyoxotungstates

Tailoring the Photophysical Signatures of BODIPY Dyes: Toward Fluorescence Standards across the Visible Spectral Region

The modern synthetic routes in organic chemistry, as well as the recent advances in high-resolution spectroscopic and microscopic techniques, have awakened a renewable interest in the development of organic fluorophores. In this regard, boron-dipyrrin (BODIPY) dyes are ranked at the top position as luminophores to be applied in photonics or biophotonics. This chromophore outstands not only by its excellent and tunable photophysical signatures, but also by the chemical versatility of its core, which is readily available to a myriad of functionalization routes. In this chapter, we show that, after a rational design, bright and photostable BODIPYs can be achieved along the whole visible spectral region, being suitable as molecular probes or active media of lasers. Alternatively, the selective functionalization of the dipyrrin core, mainly at meso position, can induce new photophysical phenomena (such as charge transfer) paving the way to the development of fluorescent sensors, where the fluorescent response is sensitive to a specific environmental property

Laser and physical properties of BODIPY chromophores in new fluorinated polymeric materials

We report on the synthesis and photophysical and lasing properties of new linear and cross-linked fluorinated polymeric materials doped with two BODIPY chromophores such as PM567 and PM597. The total fluorine content of the matrixes was varied adding to methyl methacrylate (MMA) different volumetric proportions of monomers with increased number of fluorine atoms: 2,2,2-trifluoromethyl methacrylate, 2,2,3,3,3,- pentafluoropropyl methacrylate (PFMA), and 2,2,3,3,4,4,4-heptafluorobutyl methacrylate. The rigidity of the materials was modified adding to PFMA di-, tri-, and tetra-functionalized comonomers such as ethyleneglycol dimethacrylate, pentaerythritol triacrylate, and pentaerythritol tetraacrylate. When the fluorine-modified organic matrixes were transversally pumped at 532 nm, highly stable laser operation with high, not-optimized efficiencies up to 42% was obtained. The highest photostability was recorded for PM597 doped MMA/ PFMA 70/30 linear matrix, with no sign of degradation in the laser output after 500 000 pump pulses at 30 Hz, corresponding to an accumulated pump energy of 12 300 GJ/mol. The laser action depended more on the composition of the fluorinated comonomer than on the actual fluorine content with respect to the total weight of the matrix. Narrow line width operation with tuning ranges of up to 37 nm was obtained with both pyrromethene dyes when some of the samples were incorporated into a grazing incidence grating oscillator. Good correlations between the photophysical properties and the lasing behavior have been observed. The remarkable improvement in photostability exhibited by the fluorine-modified organic hold promise in the development of industrial oriented laser applications of organic solid-state materials.This work was supported by Projects MAT2004-04643-C03-01 and MAT2004-04643-C03-02 of Spanish MCYT. O.G. thanks the MCYT for awarding her a Ramón y Cajal scientific contract. D.d.A. thanks the Comunidad Autónoma de Madrid for his predoctoral fellowshipPeer reviewe

8-phenyl-substituted dipyrromethene center dot BF2 complexes as highly efficient and photostable laser dyes

We report oil the synthesis and the photophysical and lasing properties of two new dipyrromethene.BF2, dyes. analogues of the commercial dye PM567, dissolved in liquid solutions or ill polymeric matrices of poly(methyl methacrylate) and as solid copolymers with methyl methacrylate, where the chromophore is covalently bound to the polymeric chains. The new dyes have the 8 position substituted by the group p-(acetoxypolymetlylene)phenyl or p-(methacryloyloxypolymethylene)phenyl (number of methylenes = 1 or 3). Good correlations between the photophysical properties in dilute solutions and the lasing characteristics ill moderately concentrated solutions have been observed. The presence of the 8-phenyl substituent does not significantly modify the photophysics of the chromophore. Theoretical calculations were performed to rationalize this behavior. Under transversal pumping at 534 nm, laser efficiencies up to 46% were obtained for liquid Solutions, which were found to be nearly independent of the nature of the solvent and the length of the polymethylene chain. For solid samples, lasing efficiencies of up to 23% and good photostabilities, With 96% of the initial laser Output after 100 000 PUMP pulses at 10 Hz, were established.Peer reviewe