TY  - GEN
A1  - Schott, Juliane
A1  - Kretzschmar, Jerome
A1  - Acker, Margret
A1  - Eidner, Sascha
A1  - Kumke, Michael Uwe
A1  - Drobot, Björn
A1  - Barkleit, Astrid
A1  - Taut, Steffen
A1  - Brendler, Vinzenz
A1  - Stumpf, Thorsten
T1  - Formation of a Eu(III) borate solid species from a weak Eu(III) borate complex in aqueous solution
N2  - In the presence of polyborates (detected by 11B-NMR) the formation of a weak Eu(III) borate complex (lg β11 ∼ 2, estimated) was observed by time-resolved laser-induced fluorescence spectroscopy (TRLFS). This complex is a precursor for the formation of a solid Eu(III) borate species. The formation of this solid in solution was investigated by TRLFS as a function of the total boron concentration: the lower the total boron concentration, the slower is the solid formation. The solid Eu(III) borate was characterized by IR spectroscopy, powder XRD and solid-state TRLFS. The determination of the europium to boron ratio portends the existence of pentaborate units in the amorphous solid.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 277 
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-98774
ER  - 
TY  - GEN
A1  - Mondal, Suvendu Sekhar
A1  - Behrens, Karsten
A1  - Matthes, Philipp R.
A1  - Schönfeld, Fabian
A1  - Nitsch, Jörn
A1  - Steffen, Andreas
A1  - Primus, Philipp-Alexander
A1  - Kumke, Michael Uwe
A1  - Müller-Buschbaum, Klaus
A1  - Holdt, Hans-Jürgen
T1  - White light emission of IFP-1 by in situ co-doping of the MOF pore system with Eu3+ and Tb3+
N2  - Co-doping of the MOF 3∞[Zn(2-methylimidazolate-4-amide-5-imidate)] (IFP-1 = Imidazolate Framework Potsdam-1) with luminescent Eu3+ and Tb3+ ions presents an approach to utilize the porosity of the MOF for the intercalation of luminescence centers and for tuning of the chromaticity to the emission of white light of the quality of a three color emitter. Organic based fluorescence processes of the MOF backbone as well as metal based luminescence of the dopants are combined to one homogenous single source emitter while retaining the MOF's porosity. The lanthanide ions Eu3+ and Tb3+ were doped in situ into IFP-1 upon formation of the MOF by intercalation into the micropores of the growing framework without a structure directing effect. Furthermore, the color point is temperature sensitive, so that a cold white light with a higher blue content is observed at 77 K and a warmer white light at room temperature (RT) due to the reduction of the organic emission at higher temperatures. The study further illustrates the dependence of the amount of luminescent ions on porosity and sorption properties of the MOF and proves the intercalation of luminescence centers into the pore system by low-temperature site selective photoluminescence spectroscopy, SEM and EDX. It also covers an investigation of the border of homogenous uptake within the MOF pores and the formation of secondary phases of lanthanide formates on the surface of the MOF. Crossing the border from a homogenous co-doping to a two-phase composite system can be beneficially used to adjust the character and warmth of the white light. This study also describes two-color emitters of the formula Ln@IFP-1a–d (Ln: Eu, Tb) by doping with just one lanthanide Eu3+ or Tb3+.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 190 
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-79953
SP  - 4623
EP  - 4631
ER  - 
TY  - GEN
A1  - Schwarze, Thomas
A1  - Müller, Holger
A1  - Ast, Sandra
A1  - Steinbrück, Dörte
A1  - Eidner, Sascha
A1  - Geißler, Felix
A1  - Kumke, Michael Uwe
A1  - Holdt, Hans-Jürgen
T1  - Fluorescence lifetime-based sensing of sodium by an optode
N2  - We report a 1,2,3-triazol fluoroionophore for detecting Na+ that shows in vitro enhancement in the Na+-induced fluorescence intensity and decay time. The Na+-selective molecule 1 was incorporated into a hydrogel as a part of a fiber optical sensor. This sensor allows the direct determination of Na+ in the range of 1–10 mM by measuring reversible fluorescence decay time changes.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 182 
KW  - ion optodes
KW  - sensors
KW  - indicators
KW  - chromoionophore
KW  - ionophore
KW  - membrane
KW  - switches
KW  - systems
KW  - samples
KW  - green
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-76785
SP  - 14167
EP  - 14170
PB  - The Royal Society of Chemistry
CY  - Cambridge
ER  -