Recent developments in sensing devices based on polymeric systems

This review is focused on the analysis of recent developments in the application of polymers in the detection and quantification of target species. The work begins with a description of the polymers that are employed as sensory materials, covering molecularly imprinted polymers or MIPs, hybrid polymers, acrylic polymers, conductive polymers, polymers with chiral motifs and also the use of polymeric arrays. After the description of the sensory polymers, the different target species which can be detected using sensory polymeric devices, including metallic cations and anionic species, gases, explosives, radionuclides and bacteria or the recent biomedical and biological applications is described. Finally, the sensory devices fabricated using smart polymers, including, for example, sensory devices based on Quartz Crystal Microbalances or the use of micro and nanoporous materials as substrates for sensory polymeric coatings is listed and reviewed. The work also details the different detection mechanisms based on the type of response of the sensory polymers, such as electrical, piezoelectric or fluorescence. In brief, the review details a review of the research work published in the last 10 years in this quickly evolving field, with special emphasis in the biomedical and biological applications, which have emerged recently raising great attention. To conclude, some perspectives and future challenges that must be overcome by this research field in the next years is exposed.FEDER (Fondo Europeo de Desarrollo Regional) and the Spanish Agencia Estatal de Investigación (AEI) (MAT2017-84501-R

Straightforward Synthesis of Dihydrobenzo[a]fluorenes through Au(I)-Catalyzed Formal [3 + 3] Cycloadditions

Dihydrobenzo[a]fluorene derivatives have been prepared by a formal intramolecular [3 + 3] cycloaddition of o-alkynylstyrenes bearing a secondary alkyl group at the β-position of the styrene moiety. The process, catalyzed by a cationic gold(I) complex, involves a 1,2-hydride migration as the key step. 6,11-Dihydro-5H-benzo[a]fluorenes could be obtained from the initially generated 6,6a-dihydro-5H-benzo[a]fluorenes by subsequent heating of the reaction mixture under gold(I) or Brønsted acid catalysis or directly by conducting the reactions at high temperatureMICINN and FEDER (CTQ2010-15358 and CTQ2009-09949/BQU) and Junta de Castilla y Leon (BU021A09 and GR-172) for financial support. A.M.S. thanks Junta de Castilla y Leon (Consejeria de Educacion) and Fondo Social Europeo for a PIRTU contract. M.A.R. thanks MEC for a "Young Foreign Researchers" contract (SB2009-0186). P.G.-G. and M.A.F.-R. thank MICINN for "Juan de la Cierva" and "Ramon y Cajal" contractsThis document is the Accepted Manuscript version of a Published Work that appeared in final form in Organic Letters, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.acs.org/page/policy/articlesonrequest/index.htm

Formal [4 + 1] Cycloadditions of β,β-Diaryl-Substituted ortho-(Alkynyl)styrenes through Gold(I)-Catalyzed Cycloisomerization Reactions

Gold(I)-catalyzed cycloisomerization of β,β-diaryl-o-(alkynyl)- styrenes at 80 °C selectively yields dihydroindeno[2,1-a]indenes in a transformation that encompasses a formal [4 + 1] cycloaddition and takes place through a cascade 5-endo-cyclization−diene activation−iso-Nazarov cyclization. In addition, by performing the reaction at 0 °C, the same substrates exclusively give rise to benzofulvene derivatives, which have also been shown to be intermediates in the formation of the tetracyclics.Junta de Castilla y León (BU237U13) and Ministerio de Economıá y Competitividad (MINECO) and FEDER (CTQ2013-48937-C2-1-P

Smart polymers in micro and nano sensory devices

The present review presents the most recent developments concerning the application of sensory polymers in the detection and quantification of different target species. We will firstly describe the main polymers that are being employed as sensory polymers, including, for example, conducting or acrylate-based polymers. In the second part of the review, we will briefly describe the different mechanisms of detection and the target species, such as metal cations and anions, explosives, and biological and biomedical substances. To conclude, we will describe the advancements in recent years concerning the fabrication of micro and nano sensory devices based on smart polymers, with a bibliographic revision of the research work published between 2005 and today, with special emphasis on research work presented since 2010. A final section exposing the perspectives and challenges of this interesting research line will end the present review article.FEDER (Fondo Europeo de DEsarrollo Regional), and both the Spanish Ministerio de Economía, Industria y Competitividad (MAT2014-54137-R, MAT2017-84501-R) and the Consejería de Educación–Junta de Castilla y León (BU061U16

Gold(I)-catalyzed 6-endo hydroxycyclization of 7-substituted-1,6-enynes

The cyclization of o-(alkynyl)-3-(methylbut-2-enyl)benzenes, 1,6-enynes having a condensed aromatic ring at C3–C4 positions, has been studied under the catalysis of cationic gold(I) complexes. The selective 6-endo-dig mode of cyclization observed for the 7-substituted substrates in the presence of water or methanol giving rise to hydroxy(methoxy)-functionalized dihydronaphthalene derivatives is highly remarkable in the context of the observed reaction pathways for the cycloisomerizations of 1,6-enynes bearing a trisubstituted olefinMinisterio de Ciencia e Innovación (MICINN) and FEDER (CTQ2010-15358

Thermal diagnostic of the Optical Window on board LISA Pathfinder

Vacuum conditions inside the LTP Gravitational Reference Sensor must comply with rather demanding requirements. The Optical Window (OW) is an interface which seals the vacuum enclosure and, at the same time, lets the laser beam go through for interferometric Metrology with the test masses. The OW is a plane-parallel plate clamped in a Titanium flange, and is considerably sensitive to thermal and stress fluctuations. It is critical for the required precision measurements, hence its temperature will be carefully monitored in flight. This paper reports on the results of a series of OW characterisation laboratory runs, intended to study its response to selected thermal signals, as well as their fit to numerical models, and the meaning of the latter. We find that a single pole ARMA transfer function provides a consistent approximation to the OW response to thermal excitations, and derive a relationship with the physical processes taking place in the OW. We also show how system noise reduction can be accomplished by means of that transfer function.Comment: 20 pages, 14 figures; accepted for publication in Class. Quantum Gra

The LISA PathFinder DMU and Radiation Monitor

The LISA PathFinder DMU (Data Management Unit) flight model was formally accepted by ESA and ASD on 11 February 2010, after all hardware and software tests had been successfully completed. The diagnostics items are scheduled to be delivered by the end of 2010. In this paper we review the requirements and performance of this instrumentation, specially focusing on the Radiation Monitor and the DMU, as well as the status of their programmed use during mission operations, on which work is ongoing at the time of writing.Comment: 11 pages, 7 figures, prepared for the Proceedings of the 8th International LISA Symposium, Classical and Quantum Gravit

Synthesis of Functionalized 1H-Indenes and Benzofulvenes through Iodocyclization of o-(Alkynyl)styrenes

A convenient method for the preparation of synthetically useful 3- iodoindene derivatives has been developed. This protocol, based on the 5-endo iodocyclization reaction of o-(alkynyl)styrenes, represents one of the scarce examples of halocyclizations using olefins as nucleophilic counterparts and allows the synthesis of both 3-iodo-1H-indenes (from β-alkyl-β-alkyl/aryl-o-(alkynyl)styrenes) and 3-iodobenzofulvenes (from β,β-diaryl-o-(alkynyl)styrenes) in good yields under mild reaction conditions. In addition, related alkoxyiodocyclization processes are described, which are particularly interesting in their intramolecular version because they allow the synthesis of heteropolycyclic structures containing the indene core. Finally, the usefulness of the prepared 3-iodoindenes has been demonstrated by the synthesis of several polysubstituted indene derivatives through conventional palladium-catalyzed cross-coupling reactions and iodine−lithium exchange processes.Ministerio de Economiá y Competitividad (MINECO) and FEDER (CTQ2013-48937- C2-1P) and Junta de Castilla y León (BU237U13 and BU076U16