[structure: see text]. The synthesis and nonlinear optical characterization of two novel heteroaromatic-based chromophores is described. new dyes present an A-pi-D-pi-A general framework, where A a pi-deficient heteroaromatic ring (pyridine, quinoline, benzothiazole) D pi-excessive pyrrolyl moiety. Both systems exhibit large two-photon absorption (TPA) values in the femtoseconds regime (TPA cross section as high 150 x 10(-50) cm(4) s photon(-1) molecule(-1) with fs laser pulses). Their...

Singlet oxygen sensitization by organic molecules is a topic of major interest in the development both efficient photodynamic therapy (PDT) and aerobic oxidations under complete green chemistry conditions. We report on design, synthesis, biology, spectroscopic characterization (vis-NIR linear two-photon absorption spectroscopy, singlet generation efficiencies for one- excitation, electrochemistry, intrinsic dark toxicity, cellular uptake, subcellular localization) three classes innovative...

The controversial nature of the fluorescent properties carbon dots (CDs), ascribed either to surface states or small molecules adsorbed onto nanostructures, is an unresolved issue. To date, accurate picture CDs and exhaustive structure–property correlation are still lacking. Using two unconventional spectroscopic techniques, fluorescence spectroscopy (FCS) time-resolved electron paramagnetic resonance (TREPR), we contribute fill this gap. Although micrographs indicate presence cores, FCS...

The first examples of heterocycle-based multi-branched dyes with efficient two-photon absorption (TPA) activity are reported; the novel chromophores exhibit large TPA cross sections (as high as 1600 x 10(-50) cm4 s photon(-1) molecule(-1), measured 150 fs laser pulses at 800 nm); a strong cooperative enhancement in branched systems respect to one-dimensional sub-units is found.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDoes diphenylacetylene (tolan) fluoresce from its second excited singlet state? Semiempirical MO calculations and fluorescence quantum yield measurementsCamilla Ferrante, Uwe Kensy, Bernhard DickCite this: J. Phys. Chem. 1993, 97, 51, 13457–13463Publication Date (Print):December 1, 1993Publication History Published online1 May 2002Published inissue 1 December...

Abstract Mitochondrial dysfunction is implicated in most neurodegenerative diseases, including Alzheimer's disease (AD). We here combined experimental and computational approaches to investigate mitochondrial health bioenergetic function neurons from a double transgenic animal model of AD (PS2APP/B6.152H). Experiments primary cortical demonstrated that had reduced respiratory capacity. Interestingly, the predicted this phenotype could not be explained by any defect chain (RC), but closely...

Abstract A comparative study between two novel, highly water soluble, ruthenium(II) polypyridyl complexes, [Ru(phen) 2 L ′] and Cu(II) ( ‐Cu II ), containing the polyaazamacrocyclic unit 4,4′‐(2,5,8,11,14‐pentaaza[15])‐2,2′‐bipyridilophane ′), is herein reported. interact with calf‐thymus DNA efficiently cleave plasmid when light‐activated. They also possess great penetration abilities photo‐induced biological activities, evaluated on an A375 human melanoma cell line, being most effective....

The burgeoning interest raised by carbon dots (CDs) is an epitome of the urgency to develop green and biocompatible alternatives inorganic hybrid quantum dots. fast-paced development synthetic approaches for CDs over past few years has left many open questions on their characterization. Herein, we further confirm how standardization cannot disregard presence fluorescent molecular byproducts. On contrary, show emissive properties our solvothermally synthesized largely stem from free adducts...

The self-assembly of surfactant-based structures that rely for their formation on the combination a thermodynamically controlled and dissipative pathway is described. Adenosine triphosphate (ATP) acts as high-affinity template triggers assembly at low surfactant concentrations. presence these assemblies creates conditions activation process by weak-affinity substrate. substrate-induced recruitment additional surfactants leads to spontaneous catalytic hotspots in ATP-stabilized cleave As...

Vibrational echo experiments were performed on the IR active CO stretching modes (∼2000 cm−1) of rhodium dicarbonylacetylacetonate [Rh(CO)2acac] and tungsten hexacarbonyl [W(CO)6] in dibutylphthalate a mutant myoglobin-CO (H64V-CO) glycerol–water using ps pulses from free electron laser. The decays display pronounced beats are nonexponential. nonexponential arise because bandwidths laser exceed vibrational anharmonicities, leading to excitation dephasing multilevel coherence. From beat...

The microwave-enhanced synthesis, comparative singlet oxygen sensitization efficiency, and nonlinear optical characterization of a new β-functionalized porphyrin its copper complex are described. We show that the introduction donor−acceptor push−pull conjugated fragment in β position strongly perturbs electronic structure leading to remarkable one- two-photon NIR absorption enhancement.

Time dependent density functional theory and polarizable continuum model have been used to describe tetra-phenyl-porphyrin derivatives in different solvents at pH values. Our results show that last generation functionals are able with good accuracy the photophysics of title compounds, including physical–chemical properties excited electronic states. In particular, strong modification polarizabilities induced some cases by electron excitation could explain a recent hypothesis about NLO...

The preparation and characterization of a self-assembled material showing high nonlinear response good photostability to ultrashort laser pulses is presented. built by alternate deposition tetrakis(4-sulfonatophenyl)porphyrin diacid (H4TPPS2−) poly(diallyldimethylammonium chloride) (PDDA) forming electrostatically multilayers (ESAMs). UV-visible absorption emission experiments show that in this matrix H4TPPS2− present mainly its J-aggregated form. Furthermore, linear dichroism on 3 bilayer...

We present the design, synthesis, and structural characterization of short conjugation length squaraine structures having relevant two-photon absorption (TPA) performances in 700−800 nm regime. show particular how it is possible to tune TPA performances, only marginally affecting linear absorption.

The next generation of adaptive, intelligent chemical systems will rely on a continuous supply energy to maintain the functional state. Such require methodology that provides precise control over dissipation process, and thus, lifetime transiently activated function. This manuscript reports use structurally diverse fuels two different under dissipative conditions: transient signal formation self-assembled aggregates. stored in is dissipated at rates by an enzyme, which installs dependence...

The design of novel nanostructures with tailored opto-electronic properties is a crucial step for third-generation photovoltaics, and the development cheap environmentally compatible materials still challenge. Carbon quantum dots (CQDs) emerged as promising candidates but usually low processability poor electron-donor hampered their photovoltaic applications. We tackle these issues through synthesis photophysical characterization N-doped CQDs functionalized different thiophene-containing...

Abstract It has been suggested that the inferior longitudinal fasciculus (ILF) may play an important role in several aspects of language processing such as visual object recognition, memory, lexical retrieval, reading, and specifically, naming stimuli. In particular, ILF appears to convey information from occipital lobe anterior temporal (ATL). However, direct evidence proving essential semantics remains limited controversial. The first aim this study was prove patients with a brain glioma...

The transient absorption (TA) and two-photon (TPA) spectra of a water-soluble porphyrin, 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin (H4TPPS2-) diacid, in the monomeric J-aggregated form are reported. TA spectra, measured with ultrafast laser pulses, were excited at 403 nm probed wavelengths varying 440−1100 range. While spectrum J-aggregate has been already investigated, but only 450−750 region (Kano, H.; Kobayashi, T. J. Chem. Phys. 2002, 116, 184), monomer never investigated...

The linear and nonlinear optical properties of the heteroaromatic push-pull-push two-photon absorbing dye N-methyl-2,5-bis[1-(N-methylpyrid-4-yl)ethen-2-yl]-pyrrole ditriflate (PEPEP) are reported. determination absorption (TPA) cross-section spectrum has been performed with different techniques: femtosecond TPA-white light continuum probe experiments, two-photon-induced fluorescence, open aperture Z-scan measurements using both nanosecond laser pulses. measured TPA cross sections their...

The possibility to exploit a bottom-up approach design and synthesize multichromophoric structures from single molecular unit is strategic for the targeted synthesis of compounds with well defined linear nonlinear absorption properties. In this view, it important be able predict properties units, based on knowledge individual chromophores their mutual arrangement. To end, we present combined experimental theoretical study 4-(para-di-n-butylaminostyryl)-pyridine, push–pull molecule, its...

Screening nanoparticle toxicity directly on cell culture can be a fast and cheap technique. Nevertheless, to obtain results in accordance with those observed live animals, the conditions which cells are cultivated should resemble one encountered systems. Microfluidic devices offer possibility satisfy this requirement, particular endothelial lines, because they capable reproduce flowing media shear stress experienced by these lines vivo. In work, we exploit microfluidic device observe how...

Nature adopts complex chemical networks to finely tune biochemical processes. Indeed, small biomolecules play a key role in regulating the flux of metabolic pathways. Chemistry, which was traditionally focused on reactions simple mixtures, is dedicating increasing attention network reactivity highly synthetic systems, able display new kinetic phenomena. Herein, we show that addition monophosphate nucleosides mixture amphiphiles and reagents leads selective templated formation self-assembled...