Novel solid-state emissive polymers and polymeric blends from a T-Shaped benzodifuran scaffold: A comparative study

Two novel polyimines were synthesized from a benzodifuran based diamino monomer and two dialdehydes bearing bulky groups and a flexible spacer. The polymers display tuned luminescence performance according to the presence of half-salen groups. The effect of the intramolecular bond on the emission properties were examined. Two model compounds, replicating the same emissive Schiff base cores, were synthetized. From the models, dye-doped blends in the fluorophore/matrix ratio, resembling the polymers, were produced. Amorphous thin films of the covalent polymers and the polymeric blends were obtained by spin-coating technique. The Photoluminescent (PL) response of the different macromolecular systems were qualitatively and quantitatively examined and compared

A novel DR/NIR T-shaped aiegen: Synthesis and x-ray crystal structure study

We developed a new benzodifuran derivative as the condensation product between 2,6-diamino-4-(4-nitrophenyl)benzo[1,2-b:4,5-b’]difuran-3,7-dicarboxylate and 3-hydroxy-2-naphthaldehyde. The intramolecular hydrogen-bond interactions in the terminal half-salen moieties produce a sterically encumbered highly conjugated main plane and a D-A-D (donor-acceptor-donor) T-shaped structure. The novel AIEgen (aggregation-induced enhanced emission generator) fulfils the requirement of RIR (restriction of intramolecular rotation) molecules. DR/NIR (deep red/near infrared) emission was recorded in solution and in the solid state, with a noteworthy photoluminescence quantum yield recorded on the neat crystals which undergo some mechanochromism. The crystal structure study of the probe from data collected at a synchrotron X-ray source shows a main aromatic plane π-stacked in a columnar arrangement

Stimuli-responsive zinc (Ii) coordination polymers: A novel platform for supramolecular chromic smart tools

The unique role of the zinc (II) cation prompted us to cut a cross-section of the large and complex topic of the stimuli-responsive coordination polymers (CPs). Due to its flexible coordination environment and geometries, easiness of coordination–decoordination equilibria, “optically innocent” ability to “clip” the ligands in emissive architectures, non-toxicity and sustainability, the zinc (II) cation is a good candidate for building supramolecular smart tools. The review summarizes the recent achievements of zinc-based CPs as stimuli-responsive materials able to provide a chromic response. An overview of the past five years has been organised, encompassing 1, 2 and 3D responsive zinc-based CPs; specifically zinc-based metallorganic frameworks and zinc-based nanosized polymeric probes. The most relevant examples were collected following a consequential and progressive approach, referring to the structure–responsiveness relationship, the sensing mechanisms, the analytes and/or parameters detected. Finally, applications of highly bioengineered Zn-CPs for advanced imaging technique have been discussed

Arbuscular mycorrhizal fungal hyphae reduce soil erosion by surface water flow in a greenhouse experiment

This research was funded by the SMART Joint Doctoral Programme (Erasmus Mundus Programme of the European Union) and the DRS HONORS Fellowship programme of Freie Universität Berlin. This study is a contribution to an EU Marie Curie Career Integration Grant to T.C. (EC FP7-631399-SENSE

A highly water-soluble fluorescent and colorimetric pH probe

A new 5-(4-((2-(benzothiazole-2-carbonyl)hydrazono)methyl)-3-hydroxyphenoxy)N,N,N-trimethylpentan-1-aminium bromide (BTABr) fluorescent and colorimetric pH probe was easily synthesized by the condensation reaction of benzothiazole-2-carbohydrazide with 5-(4-formyl-3-hydroxyphenoxy)-N,N,N-trimethylpentan-1-aminium bromide. The benzothiazole moiety provided the emissive part of the molecule and the charged trimethyl amino group guaranteed outstanding solubility in water, for an organic molecule. pH titration experiments indicated that the probe is useful for monitoring acidic and alkaline solutions, turning reversibly in color/fluorescence just at a neutral pH value. Naked-eye colorimetric response was observed both in solution and in the solid state. In addition, the probe showed high stability and selectivity and large Stokes shifts. Because of these features, BTABr can potentially work as an on-off real-time pH sensor for intracellular pH imaging. The crystal structure of BTABr examined by single-crystal analysis showed a planar geometry of the molecule and confirmed the presence of a molecular stacking between molecules joined in a complex tridimensional hydrogen bonding pattern

Analysis of Self-Organized Criticality in the Olami-Feder-Christensen model and in real earthquakes

We perform a new analysis on the dissipative Olami-Feder-Christensen model on a small world topology considering avalanche size differences. We show that when criticality appears the Probability Density Functions (PDFs) for the avalanche size differences at different times have fat tails with a q-Gaussian shape. This behaviour does not depend on the time interval adopted and is found also when considering energy differences between real earthquakes. Such a result can be analytically understood if the sizes (released energies) of the avalanches (earthquakes) have no correlations. Our findings support the hypothesis that a self-organized criticality mechanism with long-range interactions is at the origin of seismic events and indicate that it is not possible to predict the magnitude of the next earthquake knowing those of the previous ones.Comment: 5 pages, 3 figures. New version accepted for publication on PRE Rapid Communication

A comparative study on low-temperature sol-gel ga-doped zinc oxide inverted PSCs

A low-temperature sol-gel Ga-doped ZnO (ZnO:Ga) thin film as the electron transport layer (ETL) for high efficiency inverted polymer solar cells (PSCs) has been realised. The ZnO:Ga precursor was prepared by dissolving zinc acetate and ethanolamine in the 2-methoxyethanol with Ga(NO3)3 at different concentration. Doped ZnO thin films were deposed on indium tin oxide (ITO)/glass substrates by spin-coating technique and the films annealed at 150°C for 5 minutes in air. To check performances of ZnO:Ga thin film were realized inverted polymer solar cells with the configuration ITO/ZnO:Ga/photoactive layer/MoO3/Ag. The photoactive layer was a blend of poly[(4,8-bis-(2-ethylhexyloxy)-benzo(1,2-b:4,5-b′)dithiophene)-2,6-diyl-alt-(4-(2-octanoyl)-3-fluorothieno[3,4-b]thiophene-)-2-6-diyl)] (PBDTTT-CF) and [6,6]-phenyl C71 butyric acid methyl ester ([70]PCBM) (1:1.5 w/w). In this work was investigated the effect of gallium concentration on the photovoltaic behavior of PSCs. The best efficiency of 7.7% was reached by using a 6 at% ZnO:Ga film as ETL

Chimica generale

Gli autori Donald McQuarrie e Peter A. Rock sono stati, fino alla loro scomparsa, professori di Chimica presso la University of California, Davis. Ethan B. Gallogly è professore di Chimica al Santa Monica College, California. L’opera L’approccio “cominciare dagli atomi” (o Atoms First) si è ormai affermato nei corsi di chimica generale, poiché conduce gli studenti a una comprensione più completa di argomenti complessi: si inizia con la teoria atomica e si discutono poi il legame chimico e le molecole, prima di presentare le classi di reazioni e le altre proprietà, che derivano naturalmente da legami chimici e struttura. Dopo un capitolo introduttivo sul metodo scientifico, si prosegue con gli elementi, i composti e la nomenclatura chimica, una breve presentazione di atomi, molecole e del modello nucleare dell’atomo. Si descrivono le proprietà periodiche degli elementi, illustrando un certo numero di reazioni chimiche scelte per i diversi gruppi. Dopo aver introdotto la tavola periodica, vi sono sei capitoli nei quali, usando la teoria dei quanti, si presentano i concetti fondamentali che spiegano le proprietà periodiche degli elementi. Secondo un ordine convenzionale, segue infine una serie di capitoli su reattività chimica, calcoli stechiometrici, proprietà dei gas, termochimica, liquidi e solidi, soluzioni, cinetica chimica, equilibrio chimico, acidi e basi, termodinamica, reazioni di ossido-riduzione, elettrochimica e metalli di transizione. La chimica descrittiva viene invece trattata nei cosiddetti Interchapter, brevi sezioni di una decina di pagine ciascuna, che possono essere incluse nel programma o assegnate come letture. Sono disponibili (in lingua inglese) sul sito www.McQuarrieGeneralChemistry.com. In tutto il libro si trovano, nei punti opportuni, i riferimenti agli Interchapter appropriat

Extension of the rigid‐constraint method for the heuristic suboptimal parameter tuning to ten sensor fusion algorithms using inertial and magnetic sensing

The orientation of a magneto‐inertial measurement unit can be estimated using a sensor fusion algorithm (SFA). However, orientation accuracy is greatly affected by the choice of the SFA parameter values which represents one of the most critical steps. A commonly adopted approach is to fine‐tune parameter values to minimize the difference between estimated and true orientation. However, this can only be implemented within the laboratory setting by requiring the use of a concurrent gold‐standard technology. To overcome this limitation, a Rigid‐Constraint Method (RCM) was proposed to estimate suboptimal parameter values without relying on any orientation reference. The RCM method effectiveness was successfully tested on a single‐parameter SFA, with an average error increase with respect to the optimal of 1.5 deg. In this work, the applicability of the RCM was evaluated on 10 popular SFAs with multiple parameters under different experimental scenarios. The average residual between the optimal and suboptimal errors amounted to 0.6 deg with a maximum of 3.7 deg. These encouraging results suggest the possibility to properly tune a generic SFA on different scenarios without using any reference. The synchronized dataset also including the optical data and the SFA codes are available online

A novel l-shaped fluorescent probe for aie sensing of zinc (Ii) ion by a dr/nir response

In the field of optical sensors, small molecules responsive to metal cations are of current interest. Probes displaying aggregation-induced emission (AIE) can solve the problems due to the aggregation-caused quenching (ACQ) molecules, scarcely emissive as aggregates in aqueous media and in tissues. The addition of a metal cation to an AIE ligand dissolved in solution can cause a “turn-on” of the fluorescence emission. Half-cruciform-shaped molecules can be a winning strategy to build specific AIE probes. Herein, we report the synthesis and characterization of a novel L-shaped fluorophore containing a benzofuran core condensed with 3-hydroxy-2-naphthaldehyde crossed with a nitrobenzene moiety. The novel AIE probe produces a fast colorimetric and fluorescence response toward zinc (II) in both in neutral and basic conditions. Acting as a tridentate ligand, it produces a complex with enhanced and red-shifted emission in the DR/NIR spectral range. The AIE nature of both compounds was examined on the basis of X-ray crystallography and DFT analysis