3,242 research outputs found

    2,4,5-Tri(hetero)arylimidazoles: design, synthesis and characterization as novel TPA Chromophores and Optical Chemosensors

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    2,4,5-Tri(hetero)aryl-imidazoles are a versatile class of compounds with a wide range of applications in diverse areas such as medicinal or materials chemistry due to their biological activity, as well their optoelectronic properties. Our earlier studies showed that the optical and thermal properties of these derivatives could be tuned by substitution of aryl groups at positions 2, 4 and 5 by 5-membered heterocycles such as thiophene and furan. This raises the potential for several innovative applications of these pi-conjugated systems in nonlinear optics (e.g. second harmonic generators (SHG)), chemosensors, OLEDs and DNA intercalators. Recent results from our research group concerning the design, synthesis and characterization of novel 2,4,5-tri(hetero)aryl-imidazoles 1 (Figure 1), as two-photon absorption (TPA) chromophores and/or as optical chemosensors will be presented and discussed.Fundação para a Ciência e a Tecnologia (FCT)Acknowledgements: Thank are due to Fundação para a Ciência e Tecnologia (Portugal) and FEDER-COMPETE for financial support through Centro de Química (PEst-C/QUI/UI0686/2011 (F-COMP-01-0124-FEDER-022716)) and Centro de Física - Universidade do Minho (Project PTDC/CTM/105597/2008 (FCOMP-01-0124-FEDER-009457)), a PhD grant to R.C.M. Ferreira (SFRH/BD/86408/2012) and a a post-doctoral grant to R.M.F. Batista (SFRH/BPD/79333/2011). The NMR spectrometer Bruker Avance III 400 is part of the National NMR Network and was purchased with funds from FCT and FEDER

    Design, synthesis and evaluation of π-conjugated heterocyclic systems as novel chromo-fluorogenic probes

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    The design and synthesis of chromo-fluorogenic probes for several analytes (anions, cations and neutral molecules) is a current and appealing topic of research with important applications in environmental monitoring and biological system characterization. Using these probes detection can being accomplished with simple readily available instrumentation (when using colorimetric probes) and at extremely low detection limits (when using fluorescence probes). π-Conjugated heterocyclic compounds are versatile systems with a wide range of applications in diverse areas such as supramolecular, medicinal or materials chemistry due to their biological activity, as well their optoelectronic properties.1-3 In particular for the design of chromo-flurogenic probes, heterocyclic systems containing chelating groups have the ability to act as both the recognition unit, as well as the signalling unit, since variation of their absorption/fluorescence properties can happen during the recognition event. Generally, -conjugated heterocyclic systems increase intramolecular electron delocalisation, enhancing photophysical properties. With careful design, the inclusion of heterocycles can optimize analyte recognition while simultaneously leading to more intense fluorescence and, therefore, higher sensitivity.4-9 Recent examples from our research group exemplifying the design, synthesis and characterization of several families of heterocyclic systems as chromo-fluorogenic sensors for cations and anions with analytical, environmental and medicinal relevance will be presented and discussed.info:eu-repo/semantics/publishedVersio

    Effect of oxygen carriers in microbial and plant cell cultures.

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    Dissolved oxygen concentration is one of the most limiting factors in aerobic cultures, due to the poor solubility of oxygen in aqueous media. In many processes, the microorganisms growth and production can be affected as a result of insufficient oxygen supply to the broths [1, 2]. To increase oxygen solubility, some methods can be used, such as the increment of aeration or agitation rates or decrease of the solution temperature

    Customized housing design: Tools to enable inhabitants to co-design their house

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    In architecture, the individual needs and preferences of the end users need to be achieved in order to ensure a successful design. Standardized houses have been for long the reason for inhabitants' lack of satisfaction. The participation of inhabitants in the design process of their own houses is a crucial aspect to address housing customization, however there is a lack of effective tools to help inhabitants co-design their houses. Generative design solutions seem to be an effective way to address mass customization problem. In this paper we present a literature review on computer aided design systems that allow inhabitants to design, or partially design, their own houses. Existing solutions are classified in several categories (as generation process, target users, type of outcome, type of interaction, availability) regarding to what they accomplish and then analysed.info:eu-repo/semantics/publishedVersio

    Using digital tools to facilitate co-design in housing projects

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    Community participation in architecture and urban planning is crucial for the satisfaction of end users. Housing that are not adjusted to inhabitants’ needs lead to modification works that generate unnecessary waste. This could be avoided if the design of houses was defined from the beginning with the participation of inhabitants. The use of digital technologies benefits design participatory processes by allowing non-design specialists to obtain a better understanding of space and design possibilities. There exist digital tools for housing customization, but these were not developed along with potential users. The aim of the present work is to define the requirements for a digital design tool that facilitates the involvement of inhabitants in the definition of the design of their homes.info:eu-repo/semantics/publishedVersio

    Paleomagnetism of the dykes of the Ponta Grossa arch

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    Formylation, dicyanovinylation and tricyanovinylation on 5-alkoxy- and 5-amino-substituted-2,2´-bithiophenes

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    Several donor-acceptor-substituted bithiophenes were synthesized by functionalization of the corresponding 5-alkoxy- or 5-aminobithiophenes 1 by different methods: Vilsmeier formylation, metalation followed by reaction with DMF, direct tricyanovinylation reaction using TCNE or Knoevenagel condensation starting from the corresponding 5-formyl- derivatives of 1.ICCTI/French Embassy (Technical and Scientific Cooperation Programme). Fundação para a Ciência e Tecnologia - POCTI/QUI/37816/2001, FMRH / BSAB / 134/99
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