TY  - JOUR
A1  - Adamovich, Sergey N.
A1  - Mirskova, Anna N.
A1  - Mirskov, Rudolf G.
A1  - Schilde, Uwe
T1  - Synthesis and crystal structure of 1,4,10,13-tetraoxa-7,16-diazoniumcyclo-octadecane bis(4-chloro-2-methyl-phenoxyacetate)
JF  - Chemistry central journal
N2  - 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.
Y1  - 2011
U6  - https://doi.org/10.1186/1752-153X-5-23
SN  - 1752-153X
VL  - 5
IS  - 17
PB  - BioMed Central
CY  - London
ER  - 
TY  - JOUR
A1  - Adelsberger, Joseph
A1  - Meier-Koll, Andreas
A1  - Bivigou Koumba, Achille Mayelle
A1  - Busch, Peter
A1  - Holderer, Olaf
A1  - Hellweg, Thomas
A1  - Laschewsky, André
A1  - Müller-Buschbaum, Peter
A1  - Papadakis, Christine M.
T1  - The collapse transition and the segmental dynamics in concentrated micellar solutions of P(S-b-NIPAM) diblock copolymers
JF  - Colloid and polymer science : official journal of the Kolloid-Gesellschaft
N2  - 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).
KW  - Block copolymers
KW  - Responsive polymers
KW  - Small-angle neutron scattering
KW  - Neutron spin-echo spectroscopy
Y1  - 2011
U6  - https://doi.org/10.1007/s00396-011-2382-3
SN  - 0303-402X
VL  - 289
IS  - 5-6
SP  - 711
EP  - 720
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Ahnert, Karsten
A1  - Abel, Markus
A1  - Kollosche, Matthias
A1  - Jorgensen, Per Jorgen
A1  - Kofod, Guggi
T1  - Soft capacitors for wave energy harvesting
JF  - Journal of materials chemistry
N2  - 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.
Y1  - 2011
U6  - https://doi.org/10.1039/c1jm12454d
SN  - 0959-9428
SN  - 1364-5501
VL  - 21
IS  - 38
SP  - 14492
EP  - 14497
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Antoniou, Stella
A1  - Pashalidis, I.
A1  - Gessner, Andre
A1  - Kumke, Michael Uwe
T1  - The effect of humic acid on the formation and solubility of secondary solid phases (Nd(OH)CO3 and Sm(OH)CO3)
JF  - Radiochimica acta : international journal for chemical aspects of nuclear science and technology
N2  - 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.
KW  - Lanthanide ions
KW  - Humic acid
KW  - Solid phase
KW  - Solubility
KW  - Raman
KW  - TRLFS
KW  - DR-UV-Vis
Y1  - 2011
U6  - https://doi.org/10.1524/ract.2011.1812
SN  - 0033-8230
VL  - 99
IS  - 4
SP  - 217
EP  - 223
PB  - De Gruyter
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Antoniou, Stella
A1  - Pashalidis, Ioannis
A1  - Gessner, Andre
A1  - Kumke, Michael Uwe
T1  - Spectroscopic investigations on the effect of humic acid on the formation and solubility of secondary solid phases of Ln(2)(CO3)(3)
JF  - Journal of rare earths
N2  - 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.
KW  - lanthanide ions
KW  - humic acid
KW  - solid phase
KW  - solubility
KW  - Raman
KW  - TRLFS
KW  - DR-UV-Vis
KW  - rare earths
Y1  - 2011
U6  - https://doi.org/10.1016/S1002-0721(10)60490-5
SN  - 1002-0721
VL  - 29
IS  - 6
SP  - 516
EP  - 521
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Awad, Duha Jawad
A1  - Schilde, Uwe
A1  - Strauch, Peter
T1  - 4,4 '-Bis(tert-butyl)-2,2 '-bipyridinedichlorometal(II) - Synthesis, structure and EPR spectroscopy
JF  - Inorganica chimica acta : the international inorganic chemistry journal
N2  - 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.
KW  - 4,4 '-Bis(tert-butyl)-2,2 '-bipyridine
KW  - X-ray structure
KW  - EPR
KW  - Copper(II)
KW  - Transition metals
Y1  - 2011
U6  - https://doi.org/10.1016/j.ica.2010.08.035
SN  - 0020-1693
VL  - 365
IS  - 1
SP  - 127
EP  - 132
PB  - Elsevier
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Baranac-Stojanovic, Marija
A1  - Keinpeter, Erich
T1  - Quantification of the aromaticity of 2-Alkylidenethiazolines subjected to push-pull activity
JF  - The journal of organic chemistry
N2  - 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.
Y1  - 2011
U6  - https://doi.org/10.1021/jo200294f
SN  - 0022-3263
VL  - 76
IS  - 10
SP  - 3861
EP  - 3871
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Bartlett, Nate C. -M.
A1  - Jankunas, Justin
A1  - Goswami, Tapas
A1  - Zare, Richard N.
A1  - Bouakline, Foudhil
A1  - Althorpe, Stuart C.
T1  - 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
JF  - Physical chemistry, chemical physics : a journal of European Chemical Societies
N2  - 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.
Y1  - 2011
U6  - https://doi.org/10.1039/c0cp02460k
SN  - 1463-9076
VL  - 13
IS  - 18
SP  - 8175
EP  - 8179
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - THES
A1  - Berg, John K.
T1  - Size-dependent wetting behavior of organic molecules on solid surfaces
Y1  - 2011
CY  - Potsdam
ER  - 
TY  - THES
A1  - Berger, René
T1  - Die Deacetylierungs- Diazotierungs- Kupplungssequenz : Synthese von Aryldiazoniumtetrafluoroboraten aus Acetaniliden und deren in situ-Umsetzung mit Alken, Alkinen und Kaliumorganifluoroboraten
Y1  - 2011
CY  - Potsdam
ER  - 
TY  - JOUR
A1  - Biermann, Ursula
A1  - Meier, Michael A. R.
A1  - Butte, Werner
A1  - Metzger, Jürgen O.
T1  - Cross-metathesis of unsaturated triglycerides with methyl acrylate  synthesis of a dimeric metathesis product
JF  - European journal of lipid science and technology
N2  - 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.
KW  - Highly functionalized dimeric triglycerides
KW  - Olefin self- and cross-metathesis
KW  - Renewable resources
Y1  - 2011
U6  - https://doi.org/10.1002/ejlt.201000109
SN  - 1438-7697
VL  - 113
IS  - 1
SP  - 39
EP  - 45
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Bland-Hawthorn, Joss
A1  - Ellis, S. C.
A1  - Leon-Saval, S. G.
A1  - Haynes, R.
A1  - Roth, Martin M.
A1  - Löhmannsröben, Hans-Gerd
A1  - Horton, A. J.
A1  - Cuby, J. -G.
A1  - Birks, T. A.
A1  - Lawrence, J. S.
A1  - Gillingham, P.
A1  - Ryder, S. D.
A1  - Trinh, C.
T1  - A complex multi-notch astronomical filter to suppress the bright infrared sky
JF  - Nature Communications
N2  - 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.
Y1  - 2011
U6  - https://doi.org/10.1038/ncomms1584
SN  - 2041-1723
VL  - 2
IS  - 50
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - JOUR
A1  - Bleger, David
A1  - Dokic, Jadranka
A1  - Peters, Maike V.
A1  - Grubert, Lutz
A1  - Saalfrank, Peter
A1  - Hecht, Stefan
T1  - Electronic decoupling approach to quantitative photoswitching in linear multiazobenzene architectures
JF  - The journal of physical chemistry : B, Condensed matter, materials, surfaces, interfaces & biophysical chemistry
N2  - 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.
Y1  - 2011
U6  - https://doi.org/10.1021/jp2044114
SN  - 1520-6106
VL  - 115
IS  - 33
SP  - 9930
EP  - 9940
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - THES
A1  - Bramborg, Andrea
T1  - Regioselektive Synthese von Alkylarenen durch ipso-substitution aromatischer Carbonsäuren
Y1  - 2011
CY  - Potsdam
ER  - 
TY  - JOUR
A1  - Bressel, Katharina
A1  - Prevost, Sylvain
A1  - Appavou, Marie-Sousai
A1  - Tiersch, Brigitte
A1  - Koetz, Joachim
A1  - Gradzielski, Michael
T1  - Phase behaviour and structure of zwitanionic mixtures of perfluorocarboxylates and tetradecyldimethylamine oxide-dependence on chain length of the perfluoro surfactant
JF  - Soft matter
N2  - 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.
Y1  - 2011
U6  - https://doi.org/10.1039/c1sm05618b
SN  - 1744-683X
VL  - 7
IS  - 23
SP  - 11232
EP  - 11242
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Buller, Jens
A1  - Laschewsky, André
A1  - Lutz, Jean-Francois
A1  - Wischerhoff, Erik
T1  - Tuning the lower critical solution temperature of thermoresponsive polymers by biospecific recognition
JF  - Polymer Chemistry
N2  - 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.
Y1  - 2011
U6  - https://doi.org/10.1039/c1py00001b
SN  - 1759-9954
VL  - 2
IS  - 7
SP  - 1486
EP  - 1489
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Cockburn, Robert A.
A1  - Siegmann, Rebekka
A1  - Payne, Kevin A.
A1  - Beuermann, Sabine
A1  - McKenna, Timothy F. L.
A1  - Hutchinson, Robin A.
T1  - Free Radical Copolymerization Kinetics of gamma-Methyl-alpha-methylene-gamma-butyrolactone (MeMBL)
JF  - Biomacromolecules : an interdisciplinary journal focused at the interface of polymer science and the biological sciences
N2  - 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.
Y1  - 2011
U6  - https://doi.org/10.1021/bm200400s
SN  - 1525-7797
VL  - 12
IS  - 6
SP  - 2319
EP  - 2326
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Csuetoertoeki, Renata
A1  - Szatmari, Istvan
A1  - Koch, Andreas
A1  - Heydenreich, Matthias
A1  - Kleinpeter, Erich
A1  - Fueloep, Ferenc
T1  - Synthesis and conformational analysis of new naphth[1,2-e][1,3]oxazino[3,4-c]quinazoline derivatives
JF  - Tetrahedron
N2  - 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.
KW  - Naphthoxazinoquinazolines
KW  - NMR
KW  - Conformational analysis
KW  - DFT calculations
KW  - Hammett-Brown plots
Y1  - 2011
U6  - https://doi.org/10.1016/j.tet.2011.08.074
SN  - 0040-4020
VL  - 67
IS  - 44
SP  - 8564
EP  - 8571
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Csütörtöki, Renáta
A1  - Szatmári, István
A1  - Koch, Andreas
A1  - Heydenreich, Matthias
A1  - Kleinpeter, Erich
A1  - Fulop, Ferenc
T1  - Synthesis and conformational analysis of new naphth[1,2-e][1,3]oxazino[3,4-c]quinazoline derivatives
Y1  - 2011
SN  - 0040-4020
ER  - 
TY  - JOUR
A1  - Cywinski, Piotr J.
A1  - Moro, Artur J.
A1  - Ritschel, Thomas
A1  - Hildebrandt, Niko
A1  - Löhmannsröben, Hans-Gerd
T1  - Sensitive and selective fluorescence detection of guanosine nucleotides by nanoparticles conjugated with a naphthyridine receptor
JF  - Analytical & bioanalytical chemistry
N2  - 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.
KW  - Naphthyridine receptor
KW  - cGMP
KW  - Base pairing
KW  - Nucleotide nanosensor
KW  - Fluorescence spectroscopy
Y1  - 2011
U6  - https://doi.org/10.1007/s00216-010-4420-2
SN  - 1618-2642
VL  - 399
IS  - 3
SP  - 1215
EP  - 1222
PB  - Springer
CY  - Heidelberg
ER  -