@article{AdamovichMirskovaMirskovetal.2011, author = {Adamovich, Sergey N. and Mirskova, Anna N. and Mirskov, Rudolf G. and Schilde, Uwe}, title = {Synthesis and crystal structure of 1,4,10,13-tetraoxa-7,16-diazoniumcyclo-octadecane bis(4-chloro-2-methyl-phenoxyacetate)}, series = {Chemistry central journal}, volume = {5}, journal = {Chemistry central journal}, number = {17}, publisher = {BioMed Central}, address = {London}, issn = {1752-153X}, doi = {10.1186/1752-153X-5-23}, pages = {4}, year = {2011}, abstract = {The title compound was prepared by the reaction of 1,4,10,13-tetraoxa-7,16-diazacyclo-octadecane with 4-chloro-2-methyl-phenoxyacetic acid in a ratio of 1:2. The structure has been proved by the data of elemental analysis, IR spectroscopy, NMR ((1)H, (13)C) technique and by X-ray diffraction analysis. Intermolecular hydrogen bonds between the azonium protons and oxygen atoms of the carboxylate groups were found. Immunoactive properties of the title compound have been screened. The compound has the ability to suppress spontaneous and Con A-stimulated cell proliferation in vitro and therefore can be considered as immunodepressant.}, language = {en} } @article{AdelsbergerMeierKollBivigouKoumbaetal.2011, author = {Adelsberger, Joseph and Meier-Koll, Andreas and Bivigou Koumba, Achille Mayelle and Busch, Peter and Holderer, Olaf and Hellweg, Thomas and Laschewsky, Andr{\´e} and M{\"u}ller-Buschbaum, Peter and Papadakis, Christine M.}, title = {The collapse transition and the segmental dynamics in concentrated micellar solutions of P(S-b-NIPAM) diblock copolymers}, series = {Colloid and polymer science : official journal of the Kolloid-Gesellschaft}, volume = {289}, journal = {Colloid and polymer science : official journal of the Kolloid-Gesellschaft}, number = {5-6}, publisher = {Springer}, address = {New York}, issn = {0303-402X}, doi = {10.1007/s00396-011-2382-3}, pages = {711 -- 720}, year = {2011}, abstract = {We investigate concentrated solutions of poly(styrene-b-N-isopropyl acrylamide) (P(S-b-NIPAM)) diblock copolymers in deuterated water (D2O). Both structural changes and the changes of the segmental dynamics occurring upon heating through the lower critical solution temperature (LCST) of PNIPAM are studied using small-angle neutron scattering and neutron spin-echo spectroscopy. The collapse of the micellar shell and the cluster formation of collapsed micelles at the LCST as well as an increase of the segmental diffusion coefficient after crossing the LCST are detected. Comparing to our recent results on a triblock copolymer P(S-b-NIPAM-b-S) [25], we observe that the collapse transition of P(S-b-NIPAM) is more complex and that the PNIPAM segmental dynamics are faster than in P(S-b-NIPAM-b-S).}, language = {en} } @article{AhnertAbelKolloscheetal.2011, author = {Ahnert, Karsten and Abel, Markus and Kollosche, Matthias and Jorgensen, Per Jorgen and Kofod, Guggi}, title = {Soft capacitors for wave energy harvesting}, series = {Journal of materials chemistry}, volume = {21}, journal = {Journal of materials chemistry}, number = {38}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {0959-9428}, doi = {10.1039/c1jm12454d}, pages = {14492 -- 14497}, year = {2011}, abstract = {Wave energy harvesting could be a substantial renewable energy source without impact on the global climate and ecology, yet practical attempts have struggled with the problems of wear and catastrophic failure. An innovative technology for ocean wave energy harvesting was recently proposed, based on the use of soft capacitors. This study presents a realistic theoretical and numerical model for the quantitative characterization of this harvesting method. Parameter regions with optimal behavior are found, and novel material descriptors are determined, which dramatically simplify analysis. The characteristics of currently available materials are evaluated, and found to merit a very conservative estimate of 10 years for raw material cost recovery.}, language = {en} } @article{AntoniouPashalidisGessneretal.2011, author = {Antoniou, Stella and Pashalidis, I. and Gessner, Andre and Kumke, Michael Uwe}, title = {The effect of humic acid on the formation and solubility of secondary solid phases (Nd(OH)CO3 and Sm(OH)CO3)}, series = {Radiochimica acta : international journal for chemical aspects of nuclear science and technology}, volume = {99}, journal = {Radiochimica acta : international journal for chemical aspects of nuclear science and technology}, number = {4}, publisher = {De Gruyter}, address = {Berlin}, issn = {0033-8230}, doi = {10.1524/ract.2011.1812}, pages = {217 -- 223}, year = {2011}, abstract = {The formation of secondary Ln(III) solid phases (e.g. Nd(OH)CO3 and Sm(OH)CO3) has been studied as a function of the humic acid (HA) concentration in 0.1 M NaClO4 aqueous solution and their solubility has been investigated in the neutral pH range (6.5-8) under normal atmospheric conditions. Nd(III) and Sm(III) were selected as analogues for trivalent lanthanide and actinide ions. The solid phases under investigation have been prepared by alkaline precipitation and characterized by TGA, ATR-FTIR, XRD, TRLFS, DR-UV-Vis and Raman spectroscopy, and solubility measurements. The spectroscopic data obtained indicate that Nd(OH)CO3 and Sm(OH)CO3 are stable and remain the solubility limiting solid phases even in the presence of increased HA concentration (0.5 g/L) in solution. Upon base addition in the Ln(III)-HA system decomplexation of the previously formed Ln(III)-humate complexes and precipitation of two distinct phases occurs, the inorganic (Ln(OH)CO3) and the organic phase (HA), which is adsorbed on the particle surface of the former. Nevertheless, HA affects the particle size of the solid phases. Increasing HA concentration results in decreasing crystallite size of the Nd(OH)CO3 and increasing crystallite size of the Sm(OH)CO3 solid phase, and affects inversely the solubility of the solid phases. However, this impact on the solid phase properties is expected to be of minor relevance regarding the chemical behavior and migration of trivalent lanthanides and actinides in the geosphere.}, language = {en} } @article{AntoniouPashalidisGessneretal.2011, author = {Antoniou, Stella and Pashalidis, Ioannis and Gessner, Andre and Kumke, Michael Uwe}, title = {Spectroscopic investigations on the effect of humic acid on the formation and solubility of secondary solid phases of Ln(2)(CO3)(3)}, series = {Journal of rare earths}, volume = {29}, journal = {Journal of rare earths}, number = {6}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1002-0721}, doi = {10.1016/S1002-0721(10)60490-5}, pages = {516 -- 521}, year = {2011}, abstract = {The formation of secondary Ln(III) solid phases (e.g., Nd-2(CO3)(3) and Sm-2(CO3)(3)) was studied as a function of the humic acid concentration in 0.1 mol/L NaClO4 aqueous solution in the neutral pH range (5-6.5). The solid phases under investigation were prepared by alkaline precipitation under 100\% CO2 atmosphere and characterized by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray diffraction (XRD), time-resolved laser fluorescence spectroscopy (TRLFS), diffuse reflectance ultraviolet-visible (DR-UV-Vis), Raman spectroscopy, and solubility measurements. The spectroscopic data obtained indicated that Nd-2(CO3)(3) and Sm-2(CO3)(3) were stable and remained the solubility limiting solid phases even in the presence of increased humic acid concentration (0.5 g/L) in solution. Upon base addition in the Ln(III)-HA system, decomplexation of the previously formed Ln(III)-humate complexes and precipitation of two distinct phases occurred, the inorganic (Ln(2)(CO3)(3)) and the organic phase (HA), which was adsorbed on the particle surface of the former. Nevertheless, humic acid affected the particle size of the solid phases. Increasing humic acid concentration resulted in decreasing crystallite size of the Nd-2(CO3)(3) and increasing crystallite size of the Sm-2(CO3)(3) solid phase, and affected inversely the solubility of the solid phases. However, this impact on the solid phase properties was expected to be of minor relevance regarding the chemical behavior and migration of trivalent lanthanides and actinides in the geosphere.}, language = {en} } @article{AwadSchildeStrauch2011, author = {Awad, Duha Jawad and Schilde, Uwe and Strauch, Peter}, title = {4,4 '-Bis(tert-butyl)-2,2 '-bipyridinedichlorometal(II) - Synthesis, structure and EPR spectroscopy}, series = {Inorganica chimica acta : the international inorganic chemistry journal}, volume = {365}, journal = {Inorganica chimica acta : the international inorganic chemistry journal}, number = {1}, publisher = {Elsevier}, address = {Lausanne}, issn = {0020-1693}, doi = {10.1016/j.ica.2010.08.035}, pages = {127 -- 132}, year = {2011}, abstract = {Due to the better solubility of the 4,4'-substituted bipyridine ligand a series of 4,4'0-bis(tert-butyl)-2,2'-bipyridinedichlorometal(II) complexes, [M(tbbpy)Cl(2)], with M = Cu, Ni, Zn, Pd, Pt was synthesised and characterised. The blue copper complex 4,4'-bis(tert-butyl)-2,2'-bipyridinedichlorocopper(II) was isolated in two different polymorphic forms, as prisms 1 with a solvent inclusion and solvent-free as needles 2. Both structures were determined by X-ray structure analysis. They crystallise in the monoclinic space group P2(1)/c with four molecules in the unit cell, but with different unit cells and packing motifs. Whereas in the prisms 1, with the unit cell parameters a = 12.1613(12), b = 10.6363(7), c = 16.3074(15) angstrom, eta = 94.446(8)degrees, the packing is dominated by intra-and intermolecular hydrogen bonds, in the needles 2, with a = 7.738(1), b = 18. 333(2), c = 13.291(3) angstrom, beta = 97.512(15)degrees, only intramolecular hydrogen bonds appear and the complex molecules are arranged in columns which are stabilised by p-p-stacking interactions. In both complexes the copper has a tetrahedrally distorted coordination sphere. These copper complexes were also studied by EPR spectroscopy in solution, as frozen glass and diamagnetically diluted powder with the analogue [Pd(tbbpy)Cl(2)] as host lattice.}, language = {en} } @article{BaranacStojanovicKeinpeter2011, author = {Baranac-Stojanovic, Marija and Keinpeter, Erich}, title = {Quantification of the aromaticity of 2-Alkylidenethiazolines subjected to push-pull activity}, series = {The journal of organic chemistry}, volume = {76}, journal = {The journal of organic chemistry}, number = {10}, publisher = {American Chemical Society}, address = {Washington}, issn = {0022-3263}, doi = {10.1021/jo200294f}, pages = {3861 -- 3871}, year = {2011}, abstract = {Through-space NMR shieldings (TSNMRSs) of a series of 2-alkylidenethiazolines subjected to push-pull activity have been calculated by the GIAO method employing the nucleus-independent chemical shift (NICS) concept and visualized as iso-chemical-shielding surfaces (ICSSs). The ICSSs were applied to quantify and visualize the degree of aromaticity of the studied compounds, which has been shown to be in excellent correlation with the push-pull behavior, quantified by the quotient (pi*/pi) method. Dissection of the absolute magnetic shielding values into individual contributions of bonds and lone pairs by the natural chemical shielding-natural bond orbital (NCS-NBO) analysis has revealed unexpected details.}, language = {en} } @article{BartlettJankunasGoswamietal.2011, author = {Bartlett, Nate C. -M. and Jankunas, Justin and Goswami, Tapas and Zare, Richard N. and Bouakline, Foudhil and Althorpe, Stuart C.}, title = {Differential cross sections for H + D-2 -> HD(v '=2, j '=0,3,6,9) + D at center-of-mass collision energies of 1.25, 1.61, and 1.97 eV}, series = {Physical chemistry, chemical physics : a journal of European Chemical Societies}, volume = {13}, journal = {Physical chemistry, chemical physics : a journal of European Chemical Societies}, number = {18}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1463-9076}, doi = {10.1039/c0cp02460k}, pages = {8175 -- 8179}, year = {2011}, abstract = {We have measured differential cross sections (DCSs) for the reaction H + D-2 -> HD- (v' = 2, j' = 0,3,6,9) + D at center-of-mass collision energies E-coll of 1.25, 1.61, and 1.97 eV using the photoloc technique. The DCSs show a strong dependence on the product rotational quantum number. For the HD(v' = 2, j' = 0) product, the DCS is bimodal but becomes oscillatory as the collision energy is increased. For the other product states, they are dominated by a single peak, which shifts from back to sideward scattering as j' increases, and they are in general less sensitive to changes in the collision energy. The experimental results are compared to quantum mechanical calculations and show good, but not fully quantitative agreement.}, language = {en} } @phdthesis{Berg2011, author = {Berg, John K.}, title = {Size-dependent wetting behavior of organic molecules on solid surfaces}, address = {Potsdam}, pages = {99 S.}, year = {2011}, language = {en} } @phdthesis{Berger2011, author = {Berger, Ren{\´e}}, title = {Die Deacetylierungs- Diazotierungs- Kupplungssequenz : Synthese von Aryldiazoniumtetrafluoroboraten aus Acetaniliden und deren in situ-Umsetzung mit Alken, Alkinen und Kaliumorganifluoroboraten}, address = {Potsdam}, pages = {215 S.}, year = {2011}, language = {de} } @article{BiermannMeierButteetal.2011, author = {Biermann, Ursula and Meier, Michael A. R. and Butte, Werner and Metzger, J{\"u}rgen O.}, title = {Cross-metathesis of unsaturated triglycerides with methyl acrylate synthesis of a dimeric metathesis product}, series = {European journal of lipid science and technology}, volume = {113}, journal = {European journal of lipid science and technology}, number = {1}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1438-7697}, doi = {10.1002/ejlt.201000109}, pages = {39 -- 45}, year = {2011}, abstract = {Highly functionalized dimeric triglycerides, such as compound 2, are obtained as minor products besides branched macromolecules from the acyclic triene metathesis (ATMET) polymerization of unsaturated triglycerides such as glyceryl triundec-10-enoate 1 and methyl acrylate (MA) in the presence of the second generation Hoveyda-Grubbs catalyst. The formed amount of interesting products of lower molecular weight during the ATMET reaction depends on the ratio of MA and triglyceride, reaction time, and temperature. We isolated the dimeric metathesis product 2 and synthesized the respective partially hydrogenated dimer 3 regioselectivly in a seven step reaction sequence starting from 10-undecenoic acid 7 and glycerol. Product 3 was unambiguously characterized by (13)C and (1)H NMR and MS as well as the further intermediate products of the seven step reaction including 10,11 bromo-undecanoic acid 8, the respective brominated 1,3-diglyceride 9, the brominated 1,3-triglyceride 6, and the self-metathesis products 4 and 5 which were isolated and purified.}, language = {en} } @article{BlandHawthornEllisLeonSavaletal.2011, author = {Bland-Hawthorn, Joss and Ellis, S. C. and Leon-Saval, S. G. and Haynes, R. and Roth, Martin M. and L{\"o}hmannsr{\"o}ben, Hans-Gerd and Horton, A. J. and Cuby, J. -G. and Birks, T. A. and Lawrence, J. S. and Gillingham, P. and Ryder, S. D. and Trinh, C.}, title = {A complex multi-notch astronomical filter to suppress the bright infrared sky}, series = {Nature Communications}, volume = {2}, journal = {Nature Communications}, number = {50}, publisher = {Nature Publ. Group}, address = {London}, issn = {2041-1723}, doi = {10.1038/ncomms1584}, pages = {7}, year = {2011}, abstract = {A long-standing and profound problem in astronomy is the difficulty in obtaining deep near-infrared observations due to the extreme brightness and variability of the night sky at these wavelengths. A solution to this problem is crucial if we are to obtain the deepest possible observations of the early Universe, as redshifted starlight from distant galaxies appears at these wavelengths. The atmospheric emission between 1,000 and 1,800 nm arises almost entirely from a forest of extremely bright, very narrow hydroxyl emission lines that varies on timescales of minutes. The astronomical community has long envisaged the prospect of selectively removing these lines, while retaining high throughput between them. Here we demonstrate such a filter for the first time, presenting results from the first on-sky tests. Its use on current 8 m telescopes and future 30 m telescopes will open up many new research avenues in the years to come.}, language = {en} } @article{BlegerDokicPetersetal.2011, author = {Bleger, David and Dokic, Jadranka and Peters, Maike V. and Grubert, Lutz and Saalfrank, Peter and Hecht, Stefan}, title = {Electronic decoupling approach to quantitative photoswitching in linear multiazobenzene architectures}, series = {The journal of physical chemistry : B, Condensed matter, materials, surfaces, interfaces \& biophysical chemistry}, volume = {115}, journal = {The journal of physical chemistry : B, Condensed matter, materials, surfaces, interfaces \& biophysical chemistry}, number = {33}, publisher = {American Chemical Society}, address = {Washington}, issn = {1520-6106}, doi = {10.1021/jp2044114}, pages = {9930 -- 9940}, year = {2011}, abstract = {A strategy to optimize the photoswitching efficiency of rigid, linear multiazobenzene constructs is presented. It consists of introducing large dihedral angles between azobenzene moieties linked via aryl-aryl connections in their para positions. Four bisazobenzenes exhibiting different dihedral angles as well as three single azobenzene reference compounds have been synthesized, and their switching behavior has been studied as well as experimentally and theoretically analyzed. As the dihedral angle between the two azobenzene units increases and consequently the electronic conjugation decreases, the photochromic characteristics improve, finally leading to individual azobenzene switches operating independently in the case of the perpendicular ortho,ortho,ortho',ortho'-tetramethyl biphenyl linker. The electronic decoupling leads to efficient separation of the absorption spectra of the involved switching states and hence by choosing the appropriate irradiation wavelength, an almost quantitative E -> Z photoisomerization up to 97\% overall Z-content can be achieved. In addition, thermal Z -> E isomerization processes become independent of each other with increasing decoupling. The electronic decoupling could furthermore be proven by electrochemistry. The experimental data are supported by theory, and calculations additionally provide mechanistic insight into the preferred pathway for the thermal Z,Z -> Z,E -> E,E isomerization via inversion on the inner N-atoms. Our decoupling approach outlined herein provides the basis for constructing rigid rod architectures composed of multiple azobenzene photochromes, which display practically quantitative photoswitching properties, a necessary prerequisite to achieve highly efficient transduction of light energy directly into motion.}, language = {en} } @phdthesis{Bramborg2011, author = {Bramborg, Andrea}, title = {Regioselektive Synthese von Alkylarenen durch ipso-substitution aromatischer Carbons{\"a}uren}, address = {Potsdam}, pages = {163 S.}, year = {2011}, language = {de} } @article{BresselPrevostAppavouetal.2011, author = {Bressel, Katharina and Prevost, Sylvain and Appavou, Marie-Sousai and Tiersch, Brigitte and Koetz, Joachim and Gradzielski, Michael}, title = {Phase behaviour and structure of zwitanionic mixtures of perfluorocarboxylates and tetradecyldimethylamine oxide-dependence on chain length of the perfluoro surfactant}, series = {Soft matter}, volume = {7}, journal = {Soft matter}, number = {23}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1744-683X}, doi = {10.1039/c1sm05618b}, pages = {11232 -- 11242}, year = {2011}, abstract = {Phase behaviour and the mesoscopic structure of zwitanionic surfactant mixtures based on the zwitterionic tetradecyldimethylamine oxide (TDMAO) and anionic lithium perfluoroalkyl carboxylates have been investigated for various chain lengths of the perfluoro surfactant with an emphasis on spontaneously forming vesicles. These mixtures were studied at a constant total concentration of 50 mM and characterised by means of dynamic light scattering (DLS), electric conductivity, small-angle neutron scattering (SANS), viscosity, and cryo-scanning electron microscopy (Cryo-SEM). No vesicles are formed for relatively short perfluoro surfactants. The extension of the vesicle phase becomes substantially larger with increasing chain length of the perfluoro surfactant, while at the same time the size of these vesicles increases. Head group interactions in these systems play a central role in the ability to form vesicles, as already protonating 10 mol\% of the TDMAO largely enhances the propensity for vesicle formation. The range of vesicle formation in the phase diagram is not only substantially enlarged but also extends to shorter perfluoro surfactants, where without protonation no vesicles would be formed. The size and polydispersity of the vesicles are related to the chain length of the perfluoro surfactant, the vesicles becoming smaller and more monodisperse with increasing perfluoro surfactant chain length. The ability of the mixed systems to form well-defined unilamellar vesicles accordingly can be controlled by the length of the alkyl chain of the perfluorinated surfactant and depends strongly on the charge conditions, which can be tuned easily by pH-variation.}, language = {en} } @article{BullerLaschewskyLutzetal.2011, author = {Buller, Jens and Laschewsky, Andr{\´e} and Lutz, Jean-Francois and Wischerhoff, Erik}, title = {Tuning the lower critical solution temperature of thermoresponsive polymers by biospecific recognition}, series = {Polymer Chemistry}, volume = {2}, journal = {Polymer Chemistry}, number = {7}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1759-9954}, doi = {10.1039/c1py00001b}, pages = {1486 -- 1489}, year = {2011}, abstract = {A thermosensitive statistical copolymer based on oligo(ethylene glycol) methacrylates incorporating biotin was synthesized by free radical copolymerisation. The influence of added avidin on its thermoresponsive behaviour was investigated. The specific binding of avidin to the biotinylated copolymers provoked a marked increase of the lower critical solution temperature.}, language = {en} } @article{CockburnSiegmannPayneetal.2011, author = {Cockburn, Robert A. and Siegmann, Rebekka and Payne, Kevin A. and Beuermann, Sabine and McKenna, Timothy F. L. and Hutchinson, Robin A.}, title = {Free Radical Copolymerization Kinetics of gamma-Methyl-alpha-methylene-gamma-butyrolactone (MeMBL)}, series = {Biomacromolecules : an interdisciplinary journal focused at the interface of polymer science and the biological sciences}, volume = {12}, journal = {Biomacromolecules : an interdisciplinary journal focused at the interface of polymer science and the biological sciences}, number = {6}, publisher = {American Chemical Society}, address = {Washington}, issn = {1525-7797}, doi = {10.1021/bm200400s}, pages = {2319 -- 2326}, year = {2011}, abstract = {The propagation kinetics and copolymerization behavior of the biorenewable monomer gamma-methyl-alpha-methylene-gamma-butyrolactone (MeMBL) are studied using the Pulsed laser polymerization (PLP)/size exclusion chromatography (SEC) technique. The propagation rate coefficent for MeMBL is 15\% higher than that of its structural analogue, methyl methacrylate (MMA), with a similar activation energy of 21.8 kJ . mol(-1). When compared to MMA, MeMBL is preferentially incorporated into copolymers when reacted with styrene (ST), MMA, and n-butyl acrylate (BA); the monomer reactivity ratios fit from bulk MeMBL/ST, MeMBL/MMA, and MeMBL/BA copolymerizations are r(MeMBL) = 0.80 +/- 0.04 and r(ST) = 0.34 +/- 0.04, r(MeMBL), = 3.0 +/- 0.3 and r(MMA) = 0.33 +/- 0.01, and r(MeMBL) = 7.0 +/- 2.0 and r(BA) = 0.16 +/- 0.03, respectively. In all cases, no significant variation with temperature was found between 50 and 90 degrees C. The implicit penultimate unit effect (IPUE) model was found to adequately fit the composition-averaged copolymerization propagation rate coefficient, k(p,cop), for the three systems.}, language = {en} } @article{CsuetoertoekiSzatmariKochetal.2011, author = {Csuetoertoeki, Renata and Szatmari, Istvan and Koch, Andreas and Heydenreich, Matthias and Kleinpeter, Erich and Fueloep, Ferenc}, title = {Synthesis and conformational analysis of new naphth[1,2-e][1,3]oxazino[3,4-c]quinazoline derivatives}, series = {Tetrahedron}, volume = {67}, journal = {Tetrahedron}, number = {44}, publisher = {Elsevier}, address = {Oxford}, issn = {0040-4020}, doi = {10.1016/j.tet.2011.08.074}, pages = {8564 -- 8571}, year = {2011}, abstract = {A new highly functionalized aminonaphthol derivative, 1-(amino(2-aminophenyl)methyl)-2-naphthol (4), was synthesized by the reaction of 2-naphthol, 2-nitrobenzaldehyde and tert-butyl carbamate or benzyl carbamate, followed by reduction and/or removal of the protecting group. The aminonaphthol derivative thus obtained was converted in ring-closure reactions with formaldehyde. benzaldehyde and/or phosgene to the corresponding naphth[1,2-e][1,3]oxazino[3,4-c]quinazoline derivatives. The conformational analysis of some derivatives by NMR spectroscopy and accompanying molecular modelling are also reported.}, language = {en} } @article{CsuetoertoekiSzatmariKochetal.2011, author = {Cs{\"u}t{\"o}rt{\"o}ki, Ren{\´a}ta and Szatm{\´a}ri, Istv{\´a}n and Koch, Andreas and Heydenreich, Matthias and Kleinpeter, Erich and Fulop, Ferenc}, title = {Synthesis and conformational analysis of new naphth[1,2-e][1,3]oxazino[3,4-c]quinazoline derivatives}, issn = {0040-4020}, year = {2011}, language = {en} } @article{CywinskiMoroRitscheletal.2011, author = {Cywinski, Piotr J. and Moro, Artur J. and Ritschel, Thomas and Hildebrandt, Niko and L{\"o}hmannsr{\"o}ben, Hans-Gerd}, title = {Sensitive and selective fluorescence detection of guanosine nucleotides by nanoparticles conjugated with a naphthyridine receptor}, series = {Analytical \& bioanalytical chemistry}, volume = {399}, journal = {Analytical \& bioanalytical chemistry}, number = {3}, publisher = {Springer}, address = {Heidelberg}, issn = {1618-2642}, doi = {10.1007/s00216-010-4420-2}, pages = {1215 -- 1222}, year = {2011}, abstract = {Novel fluorescent nanosensors, based on a naphthyridine receptor, have been developed for the detection of guanosine nucleotides, and both their sensitivity and selectivity to various nucleotides were evaluated. The nanosensors were constructed from polystyrene nanoparticles functionalized by (N-(7-((3-aminophenyl) ethynyl)-1,8-naphthyridin- 2-yl) acetamide) via carbodiimide ester activation. We show that this naphthyridine nanosensor binds guanosine nucleotides preferentially over adenine, cytosine, and thymidine nucleotides. Upon interaction with nucleotides, the fluorescence of the nanosensor is gradually quenched yielding Stern-Volmer constants in the range of 2.1 to 35.9mM(-1). For all the studied quenchers, limits of detection (LOD) and tolerance levels for the nanosensors were also determined. The lowest (3 sigma) LOD was found for guanosine 3',5'-cyclic monophosphate (cGMP) and it was as low as 150 ng/ml. In addition, we demonstrated that the spatial arrangement of bound analytes on the nanosensors' surfaces is what is responsible for their selectivity to different guanosine nucleotides. We found a correlation between the changes of the fluorescence signal and the number of phosphate groups of a nucleotide. Results of molecular modeling and zeta-potential measurements confirm that the arrangement of analytes on the surface provides for the selectivity of the nanosensors. These fluorescent nanosensors have the potential to be applied in multi-analyte, array-based detection platforms, as well as in multiplexed microfluidic systems.}, language = {en} }