Fluorescent hexaaryl- and hexa-heteroaryl[3]radialenes: Synthesis, structures, and properties

• Antonio Avellaneda,
• Courtney A. Hollis,
• Xin He and
• Christopher J. Sumby

Beilstein J. Org. Chem. 2012, 8, 71–80, doi:10.3762/bjoc.8.7

• large Stokes shifts, suggests that these compounds would be useful as sensor components. Indeed, our efforts to investigate anion–π interactions [43] are being undertaken with a view to utilise [3]radialenes as a building block for the synthesis of anion sensors. Conclusion In summary, this work has

• nature of the [3]radialene core to act as anion receptors. The useful electrochemical and fluorescence properties of these compounds may allow them to be employed as building blocks of anion sensors. Experimental General experimental Melting points were determined using a Gallenkamp variable heat melting

Imidazole as a parent π-conjugated backbone in charge-transfer chromophores

• Jiří Kulhánek and
• Filip Bureš

Beilstein J. Org. Chem. 2012, 8, 25–49, doi:10.3762/bjoc.8.4

• (Figure 5, Table 3). Imidazoles 12 (DIYSP, δ = 41 GM, [38][39]) and 13 (FD3, δ = 1556 GM, [40]) were developed as two-photon absorbing and fluorescent A-π-A’ chromophores, which undergo photopolymerization or can be applied as fluorescent sensors for (homo)cysteine. Donor 4,5-disubstituted imidazole

Synthesis and characterization of new diiodocoumarin derivatives with promising antimicrobial activities

• Hany M. Mohamed,
• Ashraf H. F. Abd EL-Wahab,
• Ahmed M. EL-Agrody,
• Ahmed H. Bedair,
• Fathy A. Eid,
• Mostafa M. Khafagy and
• Kamal A. Abd-EL-Rehem

Beilstein J. Org. Chem. 2011, 7, 1688–1696, doi:10.3762/bjoc.7.199

• ]. Moreover, coumarin-based dyes and pigments are organic fluorescent materials exhibiting unique photochemical and photophysical properties, which render them useful in a variety of applications such as dye lasers, anion sensors, organic light-emitting diodes and solar cells [9][10]. Iodo-organic derivatives

Recent advances in direct C–H arylation: Methodology, selectivity and mechanism in oxazole series

• Cécile Verrier,
• Pierrik Lassalas,
• Laure Théveau,
• Guy Quéguiner,
• François Trécourt,
• Francis Marsais and
• Christophe Hoarau

Beilstein J. Org. Chem. 2011, 7, 1584–1601, doi:10.3762/bjoc.7.187

• units that occur in natural products (Scheme 10). As an example of application in materials, Hoarau recently reported a novel, sequential, palladium-catalyzed, direct arylation of ethyl oxazole-4-carboxylate, giving a rapid access to DPO and POPOP (di)carboxylate analogues (Scheme 11). Two novel sensors

Continuous preparation of carbon-nanotube-supported platinum catalysts in a flow reactor directly heated by electric current

• Alicja Schlange,
• Antonio Rodolfo dos Santos,
• Ulrich Kunz and
• Thomas Turek

Beilstein J. Org. Chem. 2011, 7, 1412–1420, doi:10.3762/bjoc.7.165

• experimental setup it is possible to produce a Pt/CNT catalyst in a continuous polyol process. Heating rates generated during the reaction are comparable to a microwave oven. The apparatus does not require expensive temperature sensors as used in microwave heating systems. The costs for the described

Fluorometric recognition of both dihydrogen phosphate and iodide by a new flexible anthracene linked benzimidazolium-based receptor

• Kumaresh Ghosh and
• Debasis Kar

Beilstein J. Org. Chem. 2011, 7, 254–264, doi:10.3762/bjoc.7.34

• biological, environmental and chemical processes [7][8][9][10]. Sensors based on anion-induced changes in fluorescence appear to be particularly attractive in anion recognition due to the simplicity and high detection limit of fluorescence [11][12]. In devising such sensors, various functional sites with

An easy assembled fluorescent sensor for dicarboxylates and acidic amino acids

• Xiao-bo Zhou,
• Yuk-Wang Yip,
• Wing-Hong Chan and
• Albert W. M. Lee

Beilstein J. Org. Chem. 2011, 7, 75–81, doi:10.3762/bjoc.7.11

• for sensing dicarboxylates. Their binding affinities toward dicarboxylates, aspartate and glutamate have been investigated in acetonitrile solution by fluorescence titration experiments. Both fluorescent sensors exhibited some ability to discriminate the antipodal forms of aspartate and glutamate

• derivative as our starting material for the design and synthesis of dicarboxylate sensors. Results and Discussion The 2-step protocol developed by Banert et al. [27] was adopted for the synthesis of the sensors. Thus nucleophilic substitution of the bromine atoms of 1,3-bis[bromomethyl]-2,4,6

• isophthalate. The preorganization of sensor 2 permits three site binding with the guests leading to enhanced complexation with aspartate and glutamate in contrast to their corresponding dicarboxylate counterparts. The chiral recognition ability of the sensors is however, only moderate. In order to be a better

A new fluorescent chemosensor for fluoride anion based on a pyrrole–isoxazole derivative

• Zhipei Yang,
• Kai Zhang,
• Fangbin Gong,
• Shayu Li,
• Jun Chen,
• Jin Shi Ma,
• Lyubov N. Sobenina,
• Albina I. Mikhaleva,
• Guoqiang Yang and
• Boris A. Trofimov

Beilstein J. Org. Chem. 2011, 7, 46–52, doi:10.3762/bjoc.7.8

• advantageous to develop high-effective sensors that can detect fluoride anion in food and animal feed. In this work, we report a new fluoride receptor 1 (Figure 1), 3-amino-5-(4,5,6,7-tetrahydro-1H-indol-2-yl)isoxazole-4-carboxamide [9], which contains receptive groups toward anions and no urea/thiourea

Chiral gels derived from secondary ammonium salts of (1R,3S)-(+)-camphoric acid

• Tapas Kumar Adalder,
• N. N. Adarsh,
• Ravish Sankolli and
• Parthasarathi Dastidar

Beilstein J. Org. Chem. 2010, 6, 848–858, doi:10.3762/bjoc.6.100

• removal of pollutants [25], catalysis [26], sensors [27], electrooptics/photonics [28], structure-directing agents [29][30] etc. The gelator molecules form SAFINs typically when a hot solution containing a small amount of gelator is cooled below a critical temperature (sol-gel temperature); the SAFINs

Organic gelators and hydrogelators

• Jean-Pierre Desvergne

Beilstein J. Org. Chem. 2010, 6, 846–847, doi:10.3762/bjoc.6.99

• nanoobject conception. Thus, owing to their non-conventional behaviour, low molecular weight gelators are very attractive for applications in various areas, including supramolecular templates or matrices, transport and release of drugs, art conservation, cosmetics, sensors, optoelectronics, actuators, etc

Hybrid biofunctional nanostructures as stimuli-responsive catalytic systems

• Gernot U. Marten,
• Thorsten Gelbrich and
• Annette M. Schmidt

Beilstein J. Org. Chem. 2010, 6, 922–931, doi:10.3762/bjoc.6.98

• and magnetic fields. Such dual responsive materials are of interest for a variety of applications ranging from magnetic separation or drug release systems to sensors and actuation [6][7][8][9][10][11][12][13]. We, and other groups, have demonstrated that magnetite nanoparticles decorated with a

Free radical homopolymerization of a vinylferrocene/cyclodextrin complex in water

• Helmut Ritter,
• Beate E. Mondrzik,
• Matthias Rehahn and
• Markus Gallei

Beilstein J. Org. Chem. 2010, 6, No. 60, doi:10.3762/bjoc.6.60

• biochemical sensors [13][14], batteries [15] and in the fuel industry [16]. However, the polymerization of the hydrophobic vinylferrocene in water has not been investigated. Recently, we studied the radical polymerization of various vinyl monomers in water using cyclodextrin as the hydrophilic host component

Anthracene functionalized terpyridines – synthesis and properties

• Falk Wehmeier and
• Jochen Mattay

Beilstein J. Org. Chem. 2010, 6, No. 54, doi:10.3762/bjoc.6.54

• terpyridyl units have been recently used to develop electrochemical sensors [4][5]. A microreview concerning the synthesis of functionalized terpyridines has also been published, since the electronic properties of the ligand are influenced by the substituents present [6]. Because of this impact of

A perfluorocyclopentene based diarylethene bearing two terpyridine moieties – synthesis, photochemical properties and influence of transition metal ions

• Falk Wehmeier and
• Jochen Mattay

Beilstein J. Org. Chem. 2010, 6, No. 53, doi:10.3762/bjoc.6.53

• recently used to develop electrochemical sensors [4][5]. A microreview concerning the synthesis of functionalized terpyridines has also been published since the electronic properties of the ligand are influenced by the substituents present [6]. Because of this impact of terpyridine derivatives in

Anthracene coupled adenine for the selective sensing of copper ions

• Kumaresh Ghosh and
• Tanushree Sen

Beilstein J. Org. Chem. 2010, 6, No. 44, doi:10.3762/bjoc.6.44

• gastrointestinal disturbance, while long-term exposure can lead to liver or kidney damage [10][11][12][13][14][15][16]. For these reasons, the past few years have witnessed a number of reports on the design and synthesis of fluorescent sensors for the detection of Cu2+ ions [17][18][19][20][21][22][23][24

Molecular recognition of organic ammonium ions in solution using synthetic receptors

• Andreas Späth and
• Burkhard König

Beilstein J. Org. Chem. 2010, 6, No. 32, doi:10.3762/bjoc.6.32

• was established as 1:1 in all cases. For ammonium salts of increased steric demand, the binding values generally decrease. The 18-crown-6 based PET sensors output was linked to the changes in the sensors’ conformational dynamics on complexation (Figure 10). The fluorescence enhancements upon guest

• addition of the diaza compounds 16 (140 to 170 fold) were three to four times higher than that of the monoaza receptor 15 (only 40 fold increase). The changes in the conformational mobility of these sensors induced by guest binding have a profound effect on their signaling. 2.3. Enantioselective

Recognition properties of receptors consisting of imidazole and indole recognition units towards carbohydrates

• Monika Mazik and
• André Hartmann

Beilstein J. Org. Chem. 2010, 6, No. 9, doi:10.3762/bjoc.6.9

• carbohydrate-based molecular recognition processes and might serve as a basis for the development of new therapeutic agents (for example, anti-infective agents) or saccharide sensors [19][20][21][22][23][24][25][26]. Our previous studies showed that mimicking the binding motifs observed in the crystal

Synthesis and binding studies of two new macrocyclic receptors for the stereoselective recognition of dipeptides

• Ana Maria Castilla,
• M. Morgan Conn and
• Pablo Ballester

Beilstein J. Org. Chem. 2010, 6, No. 5, doi:10.3762/bjoc.6.5

• receptors for the selective binding of short oligopeptides has potential applications in the development of diagnostic sensors, separation techniques, and therapeutic agents. With respect to this latter point, there is a significant interest in the advance of receptors that selectively bind the D-Ala-D-Ala

Control of stilbene conformation and fluorescence in self-assembled capsules

• Mark R. Ams,
• Dariush Ajami,
• Stephen L. Craig,
• Jye-Shane Yang and
• Julius Rebek Jr

Beilstein J. Org. Chem. 2009, 5, No. 79, doi:10.3762/bjoc.5.79

• a fully reversible process with long chain alkane guests. We are currently pursuing this application with stilbenes and studying the exchange of subunits in the process [12][13]. Many fluorescent sensors have been reported in the literature [14][15][16][17], however they usually respond to chemical

Flow through reactors for organic chemistry: directly electrically heated tubular mini reactors as an enabling technology for organic synthesis

• Ulrich Kunz and
• Thomas Turek

Beilstein J. Org. Chem. 2009, 5, No. 70, doi:10.3762/bjoc.5.70

• well-controlled electromagnetic field generation. Cheap thermocouples cannot be used as sensors for temperature measurement and control. Temperature sensors cannot always be fixed directly into the reaction mixture because of limited chemical or mechanical stability. Operation under high pressure is

An expedient and new synthesis of pyrrolo[1,2-b]pyridazine derivatives

• Rajeshwar Reddy Sagyam,
• Ravinder Buchikonda,
• Jaya Prakash Pitta,
• Himabindu Vurimidi,
• Pratap Reddy Padi and
• Mahesh Reddy Ghanta

Beilstein J. Org. Chem. 2009, 5, No. 66, doi:10.3762/bjoc.5.66

• ; tertiary butyl carbamate; tertiary butyl carbazate; α,β-unsaturated ketone; Introduction Pyrrolopyridazine derivatives have various biological applications [1][2][3][4][5][6][7][8], and their fluorescent properties have been investigated for potential use in sensors, lasers, and semiconductor devices [9

Synthesis and properties of calix[4]arene telluropodant ethers as Ag⁺ selective sensors and Ag⁺, Hg²⁺ extractants

• Yang Lu,
• Yuanyuan Li,
• Song He,
• Yan Lu,
• Changying Liu,
• Xianshun Zeng and
• Langxing Chen

Beilstein J. Org. Chem. 2009, 5, No. 59, doi:10.3762/bjoc.5.59

• +-selective ionophores in ion-selective electrodes evaluated by electromotive force measurements of polymer membrane electrodes. The tweezer-like ionophores 6–8 showed excellent extraction ability towards Ag+ and Hg2+. Keywords: calix[4]arenes; extractants; mercury; sensors; silver; telluropodant ether

• ; Introduction There is much interest in the development of compounds that selectively respond to specific metal ions for use as ion sensors. As the third generation of supramolecule, benefiting from their three-dimensional structures and easy chemical modification both at the upper- and lower-rims as well as

• their potential receptor properties for cations, anions and neutral molecules, calixarenes have enjoyed widespread use in various areas of science and technology. One of their successful applications as sensors is in analytical chemistry. They are useful for separations, enrichment, and analyses of

Novel banana-discotic hybrid architectures

• Hari Krishna Bisoyi,
• H. T. Srinivasa and
• Sandeep Kumar

Beilstein J. Org. Chem. 2009, 5, No. 52, doi:10.3762/bjoc.5.52

• applications such as one-dimensional conductors, photoconductors, light emitting diodes, photovoltaic solar cells, gas sensors etc. [10][11][12][13][14][15][16][17][18][19][20][21]. The functional capabilities of these materials are due to their easier processibility, spontaneous alignment between electrodes

Progress in liquid crystal chemistry

• Sabine Laschat

Beilstein J. Org. Chem. 2009, 5, No. 48, doi:10.3762/bjoc.5.48

• organic light emitting diodes, photovoltaic devices, organic field effect transistors, gas sensors etc. [3][4][5][6][7][8]. One of the major issues in liquid crystal research today is still the poor knowledge of structure-property relationships and thus the synthesis of whole series of structurally

Quinoline based receptor in fluorometric discrimination of carboxylic acids

• Kumaresh Ghosh,
• Suman Adhikari,
• Asoke P. Chattopadhyay and
• Purnendu Roy Chowdhury

Beilstein J. Org. Chem. 2008, 4, No. 52, doi:10.3762/bjoc.4.52

• for online and real-time analyses [4]. A large number of examples of fluorescent sensors capable of sensing ions and molecules have appeared over the past few years [5][6][7]. In this context, fluorescent sensors, which rely on guest-induced folding of flexible receptors bringing the fluorophore