TY - JOUR A1 - Grobosch, Thomas A1 - Mickler, Wulfhard A1 - Feistel, Lothar A1 - Schilde, Uwe T1 - Separation of arsenic and other heavy metals with impregnated adsorber polymers : chapter 1: synthesis of the impregnation medium and separation of arsenic Y1 - 2006 UR - http://www3.interscience.wiley.com/cgi-bin/jhome/60500203/ U6 - https://doi.org/10.1002/cite.200500170 SN - 0009-286X ER - TY - GEN A1 - Dosche, Carsten A1 - Mickler, Wulfhard A1 - Löhmannsröben, Hans-Gerd A1 - Agenet, Nicolas A1 - Vollhardt, K. Peter C. T1 - Photoinduced electron transfer in [N]phenylenes N2 - First studies of electron transfer in [N]phenylenes were performed in bimolecular quenching reactions of angular [3]- and triangular [4]phenylene with various electron acceptors. The relation between the quenching rate constants kq and the free energy change of the electron transfer (ΔG0CS ) could be described by the Rehm-Weller equation. From the experimental results, a reorganization energy λ of 0.7 eV was derived. Intramolecular electron transfer reactions were studied in an [N]phenylene bichomophore and a corresponding reference compound. Fluorescence lifetime and quantum yield of the bichromophor display a characteristic dependence on the solvent polarity, whereas the corresponding values of the reference compound remain constant. From the results, a nearly isoenergonic ΔG0CS can be determined. As the triplet quantum yield is nearly independent of the polarity, charge recombination leads to the population of the triplet state. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 23 KW - [N]phenylenes KW - photoinduced electron transfer KW - [N]phenylene dyads Y1 - 2007 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-12463 ER - TY - JOUR A1 - Mickler, Wulfhard T1 - Separation of metals by liquid-liquid-extraction with ß-diketones and 4-acyl-5-pyrazolones from different complex-forming medias Y1 - 1996 ER - TY - JOUR A1 - Uhlemann, Erhard A1 - Kümmel, Rolf A1 - Schröder, Martina A1 - Mickler, Wulfhard T1 - Selektiver Ionentransport durch flüssige Membranen Y1 - 1996 ER - TY - JOUR A1 - Uhlemann, Erhard A1 - Prochaska, Krystyna A1 - Lozynski, M. A1 - Szymanowski, Jan A1 - Mickler, Wulfhard T1 - Interfacial activity and semiempirical PM3 calculations of 2-Ethylhexanoylbenzoyl Methane Y1 - 1996 ER - TY - JOUR A1 - Uhlemann, Erhard A1 - Mickler, Wulfhard A1 - Reich, Annett A1 - Bart, Hans-Joerg T1 - Liquid membrane permeation of zinc, cadmium and nickel with 4-acyl-5-pyrazolones and ß-diketones Y1 - 1996 ER - TY - JOUR A1 - Friedrich, Alwin A1 - Hefele, Heike A1 - Mickler, Wulfhard A1 - Mönner, Anke A1 - Uhlemann, Erhard A1 - Scholz, F. T1 - Voltammetric and potentiometric studies on the stability of vanadium(IV) complexes : a comparision of sulution phase voltammetry with the voltammetry of the microcrystalline solid compounds Y1 - 1998 ER - TY - JOUR A1 - Schilde, Uwe A1 - Mickler, Wulfhard A1 - Uhlemann, Erhard T1 - Crystal structure of bis(1-phenyl-5-cyclohexyl-pentane-1,3-dionato-copper(II) Y1 - 1997 SN - 0044-2968 ER - TY - JOUR A1 - Uhlemann, Erhard A1 - Prochaska, Krystyna A1 - Cierpiszewski, Ryszard A1 - Szymanowski, Jan A1 - Mickler, Wulfhard T1 - Rate of copper extraction and interfacial activity of model ß-diketones Y1 - 1995 ER - TY - JOUR A1 - Mickler, Wulfhard A1 - Mönner, Anke A1 - Hefele, Heike A1 - Ludwig, Eberhard A1 - Uhlemann, Erhard T1 - Voltammetric studies of non-oxo Vanadium (IV)-chelates Y1 - 1997 ER - TY - JOUR A1 - Mickler, Wulfhard T1 - Liquid-liquid-extraction of copper from ammoniacal solution with 4-acylpyrazol-5-ones and ß-diketones Y1 - 1993 SN - 1-85861-042-7 ER - TY - JOUR A1 - Mickler, Wulfhard A1 - Mönner, Anke A1 - Uhlemann, Erhard T1 - Electrochemical studies on the stability of copper ß-diketone chelates Y1 - 1998 ER - TY - JOUR A1 - Janiak, Chr. A1 - Scharmann, T. G. A1 - Green, J. C. A1 - Parkin, R. P. G. A1 - Kolm, M. J. A1 - Riedel, E. A1 - Mickler, Wulfhard A1 - Elguero, J. A1 - Claramunt, R. M. A1 - Sanz, D. T1 - Effects of nitrogen substitution in Poly(pyrazolyl)borato Ligands : from orbital energy levels to C-H...O Hydrogen Bonding Y1 - 1996 ER - TY - JOUR A1 - Uhlemann, Erhard A1 - Friedrich, Alwin A1 - Hinsche, Gerald A1 - Mickler, Wulfhard A1 - Schilde, Uwe T1 - Komplexbildung und Metallextraktion mit heterocyclischen ß-Dicarbonylverbindungen im Vergleich : Struktur von 3-Phenyl-4-benzoyl-isoxazol-5-on Y1 - 1995 ER - TY - JOUR A1 - Uhlemann, Erhard A1 - Banße, Wolfgang A1 - Ludwig, Eberhard A1 - Mickler, Wulfhard A1 - Hahn, Ekkehardt A1 - Lügger, Thomas A1 - Lehmann, Andreas T1 - Mangan(IV)-Komplexe mit dreizähnigen diaciden Liganden : Kristallstruktur von Acetylacetonato- salicylaldehyd-benzoylhydrazonato(2-methanol-mangan(III) Y1 - 1995 ER - TY - JOUR A1 - Mickler, Wulfhard A1 - Reich, Annett A1 - Uhlemann, Erhard T1 - Extraction of iron (II) and iron (III) with 4-acylpyrazolones in comparision with long chain 1-phenyl-1,3- (cyclo)alkanediones Y1 - 1998 ER - TY - JOUR A1 - Cierpiszewski, Ryszard A1 - Rusinska-Roszak, D. A1 - Szymanowski, Jan A1 - Mickler, Wulfhard A1 - Uhlemann, Erhard T1 - Rate of coper extraction and structure of model ß-diketones and 4-acyl-5-pyrazolones Y1 - 1998 ER - TY - JOUR A1 - Benassi, Rois A1 - Bregulla, Antje A1 - Friedrich, Alwin A1 - Henning, Dietrich A1 - Heydenreich, Matthias A1 - Mickler, Wulfhard A1 - Kleinpeter, Erich A1 - Kempter, Gerhard A1 - Schilde, Uwe A1 - Taddei, F. T1 - NMR spectroscopic and theoretical structural study of 5-exo-methylene-substituted hydantoins Y1 - 1998 ER - TY - JOUR A1 - Dosche, Carsten A1 - Mickler, Wulfhard A1 - Löhmannsröben, Hans-Gerd A1 - Agenet, Nicolas A1 - Vollhardt, K. Peter C. T1 - Photoinduced electron transfer in [N]phenylenes N2 - First studies of electron transfer in [N]phenylenes were performed in bimolecular quenching reactions of angular [3]- and triangular [4]phenylene with various electron acceptors. The relation between the quenching rate constants k(q) and the free energy change of the electron transfer (Delta G(CS)(0)) could be described by the Rehm- Weller equation. From the experimental results, a reorganization energy lambda of 0.7 eV was derived. Intramolecular electron transfer reactions were studied in an [N]phenylene bichomophore and a corresponding reference compound. Fluorescence lifetime and quantum yield of the bichromophor display a characteristic dependence on the solvent polarity, whereas the corresponding values of the reference compound remain constant. From the results, a nearly isoenergonic charge separation process can be determined. As the triplet quantum yield is nearly independent of the polarity, charge recombination leads to the population of the triplet state. Y1 - 2007 UR - http://www.sciencedirect.com/science/journal/10106030 U6 - https://doi.org/10.1016/j.jphotochem.2006.12.038 SN - 1010-6030 ER - TY - JOUR A1 - Uhlemann, Erhard A1 - Labuda, Jan A1 - Vanickova, M. A1 - Mickler, Wulfhard T1 - Applicability of chemically modified electrodes for the determination of copper species in natural water Y1 - 1994 ER - TY - BOOK A1 - Mickler, Wulfhard A1 - Uhlemann, Erhard T1 - Studie zur Erstellung einer Stoffbilanz im Rahmen der projektbegleitenden Technikfolgenabschätzung zum MUNR-Projekt "Photovoltaik" der GFS in Frankfurt/Oder : Abschlußbericht zum Werkvertrag Y1 - 1996 PB - Univ. CY - Potsdam ER - TY - JOUR A1 - Uhlemann, Erhard A1 - Schilde, Uwe A1 - Mickler, Wulfhard T1 - Crystal structure of bis(1-phenyldecane-1,3-dionato)-copper(II), Cu(C16H21O2)2 Y1 - 1996 SN - 0044-2968 ER - TY - JOUR A1 - Herzschuh, R. A1 - Wenzlawiak, B. A1 - Plaggenborg, L. A1 - Mickler, Wulfhard A1 - Uhlemann, Erhard T1 - The characterization of the active components in commercial ß-diketone-type extractants LIX 54 and MX 80 A Y1 - 1992 ER - TY - JOUR A1 - Mickler, Wulfhard A1 - Uhlemann, Erhard T1 - Liquid-Liquid-Extraktion of copper from ammoniacal solutions with ß-diketones Y1 - 1992 ER - TY - JOUR A1 - Mickler, Wulfhard A1 - Uhlemann, Erhard A1 - Herzschuh, R. T1 - Nebenprodukte bei klassischen ß-Diketon-Synthesen Y1 - 1992 ER - TY - JOUR A1 - Mickler, Wulfhard A1 - Uhlemann, Erhard T1 - Liquid-Liquid-Extraction of copper with 4-Acylpyrazol-5-ones Y1 - 1994 ER - TY - JOUR A1 - Schröder, Martina A1 - Kümmel, Rolf A1 - Mickler, Wulfhard A1 - Uhlemann, Erhard T1 - Zur Abtrennung von Kupfer aus ammoniakalischer Lösung durch Flüssig-Flüssig-Extraktion und Flüssigmembranpermeation mit 1-Phenyl-3-methyl-4-stearoylpyrazol-5-on Y1 - 1991 ER - TY - JOUR A1 - Uhlemann, Erhard A1 - Mickler, Wulfhard A1 - Reich, Annett T1 - Extraction of zinc with long-chain ß-Diketones and 4-Acyl-5-Pyrazolones Y1 - 1995 ER - TY - JOUR A1 - Mickler, Wulfhard A1 - Uhlemann, Erhard T1 - Liquid-Liquid-Extraction of copper from ammoniacal solution with cyclohexyl substituted ß-diketones Y1 - 1993 ER - TY - JOUR A1 - Mickler, Wulfhard A1 - Uhlemann, Erhard T1 - Liquid-Liquid-Extraction of copper from ammoniacal solutions with 4-Acylpyrazolones Y1 - 1993 ER - TY - JOUR A1 - Awad, Duha Jawad A1 - Koch, Andreas A1 - Mickler, Wulfhard A1 - Schilde, Uwe A1 - Strauch, Peter T1 - EPR spectroscopy of 4, 4 '-Bis(tert-butyl)-2, 2 '-bipyridine-1, 2-dithiolatocuprates(II) in host lattices with different coordination geometries JF - Zeitschrift für anorganische und allgemeine Chemie N2 - A series of new heteroleptic MN2S2 transition metal complexes with M = Cu2+ for EPR measurements and as diamagnetic hosts Ni2+, Zn2+, and Pd2+ were synthesized and characterized. The ligands are N2 = 4, 4'-bis(tert-butyl)-2, 2'-bipyridine (tBu2bpy) and S2 =1, 2-dithiooxalate, (dto), 1, 2-dithiosquarate, (dtsq), maleonitrile-1, 2-dithiolate, or 1, 2-dicyanoethene-1, 2-dithiolate, (mnt). The CuII complexes were studied by EPR in solution and as powders, diamagnetically diluted in the isostructural planar [NiII(tBu2bpy)(S2)] or[PdII(tBu2bpy)(S2)] as well as in tetrahedrally coordinated[ZnII(tBu2bpy)(S2)] host structures to put steric stress on the coordination geometry of the central CuN2S2 unit. The spin density contributions for different geometries calculated from experimental parameters are compared with the electronic situation in the frontier orbital, namely in the semi-occupied molecular orbital (SOMO) of the copper complex, derived from quantum chemical calculations on different levels (EHT and DFT). One of the hosts, [NiII(tBu2bpy)(mnt)], is characterized by X-ray structure analysis to prove the coordination geometry. The complex crystallizes in a square-planar coordination mode in the monoclinic space group P21/a with Z = 4 and the unit cell parameters a = 10.4508(10) angstrom, b = 18.266(2) angstrom, c = 12.6566(12) angstrom, beta = 112.095(7)degrees. Oxidation and reductions potentials of one of the host complexes, [Ni(tBu2bpy)(mnt)], were obtained by cyclovoltammetric measurements. KW - 1 KW - 2-Dithiosquarate KW - 1 KW - 2-Dithiooxalate KW - 1 KW - 2-Dicyanoethene-1 KW - 2-dithiolate KW - 4 KW - 4'-Bis(tert-butyl)-2 KW - 2'-bipyridine KW - X-ray structure KW - EPR KW - Copper KW - Nickel KW - Zinc Y1 - 2012 U6 - https://doi.org/10.1002/zaac.201100517 SN - 0044-2313 VL - 638 IS - 6 SP - 965 EP - 975 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Mickler, Wulfhard T1 - Separation of heavy metals from landfill leachate by reactive liquid-liquid-extraction N2 - Based on a study of the German Ministry of Research and Technology in 1990 every year about 2.5 t of heavy metals are released per hectare of landfill by aqueous leaching. This leachate contains approximately 2000 t of heavy metals per year. Their decontaminations in accordance with the legal requirements represent an enormous potential for easing the burden on the environment. On the other hand, this potential opens new possibilities in the production and recycling of selected compounds. The composition of a given model solution corresponds to a landfill leachate resulting from a municipal dump leachate produced by an average German city. Actually, in most cases, a decontamination of such solutions occurs by the transfer of the problematic cations into insoluble compounds usually done by precipitation. The result of the procedure is an unspecific separation of all liquid components - and the "cycle of waste" (landfill- leaching-deposition) begins anew, certainly on a higher level. The objective of our work is the simultaneous separation of heavy metals from alkaline earth metals and iron in order to obtain a leachate which we can lead back to the landfill. The reactive extraction as a separation process offers the possibility of a selective separation of cations that is the separation of toxic - from unproblematic components and includes also the possibility of electrolysis or further winning processes to obtain the wished metals. For the realisation of extraction processes, several commercial extractants and technical equipments are available. Apart from iron, LIX 54 could be used advantageously for an extraction process - unfortunately without any considerable extraction of cadmium. But it is favourable to separate non toxic alkaline earth metals from problematic heavy metals. Such a complex task as the separation of cations from natural solutions cannot be solved easily in a one-step-extraction process. Better results should be obtained by the combination of different procedures, e.g. extraction, ion-exchange and precipitation. Y1 - 2001 ER - TY - JOUR A1 - Mickler, Wulfhard T1 - Reactive Liquid-liqudi-extraction of heavy metals from landfill leachates N2 - Toxic heavy metals are extracted simultaneously by reactive liquid-liquid-extraction from a model landfill leachate. This is taken as an example to generate an unproblematic waste water. Alkylphosphoric acids (commercial D2EHPA and D2EHTPA), ß-diketones, 4-Acyl-5-pyrazolones and a novel commercial alkyl-methyl-phosphonic acid are used as extractants. By means of the functions E%=f (pH, t) and lg D=f (pH, cL) some thermodynamic parameters of the extraction are determined. In the case of the alkylthiophosphoric acid the thiophilic cations are extracted advantageously in contrast to chromium, magnesium or calcium. There is no significant separation between the heavy metals and the alkaline earth metals. The complexes are extracted with the composition ML(HL)n. According to their ligand force, the presence of complexing agents in the aqueous phase (for example cyanide, tartrate, ammonia or chloride) hinders the extraction. The influence of humic acid is comparable to that of tartaric acid. Because of the formation of less soluble compounds, sulphate ions make the extraction of calcium more difficult. The extraction data points out that aromatic or chloric solvents are not advantageous in contrast to the non toxic aliphatic hydrocarbons. With the novel aminomethylphosphonic acid (ironex, BASF) the extraction of iron, indium and gallium is possible at a pH > 1.5 as ML2(HL) and ML(HL)2 resp. Copper and zinc were extracted quantitatively as 1:2 complexes only in a small pH-range between 4 to 6. Generally, the best results were found for the ß-diketones (LIX 54 included) and 4-acyl-5-pyrazolones. In these cases the toxic heavy metals could be separated quantitatively. Only 6% of calcium and 23% of magnesium are coextracted by the ligands. The extraction process can further be optimized by synergistic effects. Y1 - 2001 ER - TY - JOUR A1 - Mickler, Wulfhard T1 - Abtrennung von Schwermetallen aus Deponiesickerwässern durch Reaktivextraktion N2 - Am Beispiel eines modellierten Deponiesickerwassers wird die Möglichkeit einer simultanen Reaktivextraktion von toxischen Schwermetallen aus einer unproblematischen Matrix vorgestellt. Als Extraktionsmittel werden vergleichend Alkylphosphorsäuren (kommerzielle D2EHPA, D2EHTPA), ß-Diketone, 4-Acylpyrazol-5-one und eine neuartige kommerzielle Alkylphosphonsäure eingesetzt. Die thermodynamischen Parameter der Extraktion lassen sich mit Hilfe der Funktionen %E = f( t, pH), lg D = f ( pH, cL) bestimmen. Einflüsse von Lösungsmitteln und konkurrierende Komplexbildner in der wäßrigen Phase auf das Verteilungsgleichgewicht werden diskutiert. Inhaltsstoffe der wäßrigen Phase (Cyanid, Tartrat, Ammoniak, Huminsäuren oder Chlorid) beeinflussen entsprechend ihrer Ligandstärke die Metallabtrennung. Für den Fall der Huminsäure wird eine Größenordnung von Weinsäure gefunden. Sulfationen erschweren zusätzlich die Extraktion von Calcium. Halogenierte und aromatische Verdünnungsmittel haben gegenüber unproblematischen Kohlenwasserstoffen keinen Vorteil. Mit Aminomethylphosphonsäure (Ironex, BASF) gelingt eine quantitative Eisen, Indium- und Galliumabtrennung bei einem pH-Wert kleiner 1.5 als ML2(HL) bzw. ML(HL)2. Kupfer und Zink werden im pH-Bereich von 4-6 quantitativ als 1:2- Komplex extrahiert. Insgesamt günstige Ergebnisse zeigen die ß-Diketone (auch LIX 54) und 4-Acylpyrazol-5-one. Hier ergibt sich die Möglichkeit toxische Schwermetalle selektiv abzutrennen und eine unproblematische Matrix zu gewinnen, da Calcium nur zu 6% und Magnesium zu 23% extrahiert werden. Y1 - 2000 ER - TY - JOUR A1 - Mickler, Wulfhard T1 - Abtrennung von Schwermetallen aus Deponiesickerwässern durch Reaktivextraktion Y1 - 1999 SN - 3- 9805032-7-5 ER - TY - JOUR A1 - Mickler, Wulfhard T1 - Reactive Liquid-Liquid-Extraction of heavy metals from Landfill Leachate Y1 - 1999 SN - 3-924763-80-1 ER - TY - JOUR A1 - Mickler, Wulfhard A1 - Mönner, Anke A1 - Uhlemann, Erhard A1 - Wilke, S. A1 - Müller, H. T1 - Transfer of ß-diketone and 4-acylpyrazolone anions across the electrified water nitrobenzene interface Y1 - 1999 ER - TY - JOUR A1 - Kammer, Stefan A1 - Starke, Ines A1 - Pietrucha, Andreas A1 - Kelling, Alexandra A1 - Mickler, Wulfhard A1 - Schilde, Uwe A1 - Dosche, Carsten A1 - Kleinpeter, Erich A1 - Holdt, Hans-Jürgen T1 - 1,12-Diazaperylene and 2,11-dialkylated-1,12-diazaperylene iridium(III) complexes [Ir((CN)-N-boolean AND)(2)((NN)-N-boolean AND)]PF6: new supramolecular assemblies JF - Dalton transactions : a journal of inorganic chemistry, including bioinorganic, organometallic, and solid-state chemistry N2 - A series of new monocationic iridium(III) complexes [Ir((CN)-N-boolean AND)(2)((NN)-N-boolean AND)]PF6 with "large-surface" alpha,alpha'-diimin ligands (NN)-N-boolean AND (dap = 1,12-diazaperylene, dmedap = 2,11-dimethyl-1,12-diazaperylene, dipdap = 2,11-diisopropyl-1,12-diazaperylene) and different cyclometalating ligands (CN)-N-boolean AND (piq = 1-phenylisoquinoline, bzq = benzo[h]quinoline, ppz = 1-phenylpyrazole, thpy = 2-(2-thienyl)pyridine, ppy = 2-phenylpyridine, meppy = 2-(4-methylphenyl)pyridine, dfppy = 2-(2,4-difluorophenyl)pyridine) were synthesized. The solid structures of the complexes [Ir(piq)(2)(dap)]PF6, [Ir(bzq)(2)(dap)]PF6, [Ir(ppy)(2)(dipdap)]PF6, [Ir(piq)(2)(dmedap)]PF6, [Ir(ppy)(2)(dap)]PF6 and [Ir(ppz)(2)(dap)]PF6 are reported. In [Ir(piq)(2)(dap)]PF6, the dap ligand and one of the piq ligands of each cationic complex are involved in pi-pi stacking interactions forming supramolecular channels running along the crystallographic c axis. In the crystalline [Ir(bzq)(2)(dap)]PF6 pi-pi stacking interactions between the metal complexes lead to the formation of a 2D layer structure. In addition, CH-pi interactions were found in all compounds, which are what stabilizes the solid structure. In particular, a significant number of them were found in [Ir(piq)(2)(dap)]PF6 and [Ir(bzq)(2)(dap)]PF6. The crystal structures of [Ir(ppy)(2)(dipdap)]PF6 and [Ir(ppy)(2)(dmedap)]PF6 are also presented, being the first examples of bis-cyclometalated iridium(III) complexes with phenanthroline-type alpha,alpha'-diimin ligands bearing bulky alkyl groups in the neighbourhood of the N-donor atoms. These ligands implicate a distorted octahedral coordination geometry that in turn destabilized the Ir-N-N boolean AND N bonds. The new iridium (III) complexes are not luminescent. All compounds show an electrochemically irreversible anodic peak between 1.15 and 1.58 V, which is influenced by the different cyclometalated ligands. All of the new complexes show two reversible successive one-electron "large-surface" ligand-centred reductions around -0.70 V and -1.30 V. Electrospray ionisation mass spectrometry (ESI-MS) and collision induced decomposition (CID) measurements were used to investigate the stability of the new complexes. Thereby, the stability agreed well with the order of the Ir-N-N boolean AND N bond lengths. Y1 - 2012 U6 - https://doi.org/10.1039/c2dt30412k SN - 1477-9226 VL - 41 IS - 34 SP - 10219 EP - 10227 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Brietzke, Thomas Martin A1 - Mickler, Wulfhard A1 - Kelling, Alexandra A1 - Schilde, Uwe A1 - Krüger, Hans-Joerg A1 - Holdt, Hans-Jürgen T1 - Mono- and dinuclear Ruthenium(II)-1,6,7,12-Tetraazaperylene complexes of N,N '-Dimethyl-2,11-diaza[3.3](2,6)-pyridinophane JF - European journal of inorganic chemistry : a journal of ChemPubSoc Europe N2 - Ruthenium(II) complexes [Ru(L-N4Me2)(dape)](PF6)2 {[1](PF6)2}, [Ru(L-N4Me2)(tape)](PF6)2 {[2](PF6)2}, and [{Ru(L-N4Me2)}2(mu-tape)](PF6)4 {[3](PF6)4} were synthesized in two reaction steps by first reacting [Ru(DMSO)4Cl2] with tetraazamacrocyclic ligand N,N'-dimethyl-2,11-diaza[3.3](2,6)-pyridinophane (L-N4Me2) in ethanol under microwave irradiation to the intermediate [Ru(L-N4Me2)Cl2], which was subsequently, without further isolation, reacted with 1,12-diazaperylene (dape) or 1,6,7,12-tetraazaperylene (tape). X-ray structures of [Ru(L-N4Me2)(dape)](PF6)2, [Ru(L-N4Me2)(tape)](PF6)2.acetone, and [{Ru(L-N4Me2)}2(mu-tape)](ClO4)4.MeCN were determined. The UV/Vis absorption spectra of [1](PF6)2, [2](PF6)2, and [3](PF6)4 in acetonitrile display intense low-energy dp(Ru)?p* (dape or tape) MLCT absorption bands centered at 579, 637, and 794 nm, respectively. Reversible metal oxidations for the bimetallic complex [{Ru(L-N4Me2)}2(mu-tape)]4+ ([3]4+) are detected at 1.69 and 1.28 V vs. SCE. The potential difference ?E = 410 mV and the intervalence-charge-transfer (IVCT) transition at 2472 nm indicate a high degree of electronic interaction between the two ruthenium ions mediated through the tape bridging ligand. All three complexes, [1]2+, [2]2+, and [3]4+, were characterized by UV/Vis spectroelectrochemistry. The monooxidized and monoreduced states, [1]3+, [2]3+, [3]5+, and [1]+, [2]+, [3]3+, are accessible by reversible one-electron oxidation and one-electron reduction processes, respectively, as documented by the observation of several stable isosbestic points in the spectral progressions. The second reduction in each complex and the second oxidation in [3]4+ prove to be irreversible in these spectroelectrochemical experiments. Monoreduced species [1]+, [2]+, and [3]3+ yield EPR signals indicating that the unpaired electron is mainly centered on the large surface ligands dape or tape. KW - Ruthenium KW - Macrocyclic li-gands KW - N ligands KW - Redox chemistry KW - Mixed-valent compounds Y1 - 2012 U6 - https://doi.org/10.1002/ejic.201200667 SN - 1434-1948 IS - 29 SP - 4632 EP - 4643 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Brietzke, Thomas Martin A1 - Mickler, Wulfhard A1 - Kelling, Alexandra A1 - Holdt, Hans-Jürgen T1 - Mono- and dinuclear ruthenium(II) 1,6,7,12-tetraazaperylene complexes JF - Dalton transactions : a journal of inorganic chemistry, including bioinorganic, organometallic, and solid-state chemistry N2 - We report the synthesis of free 1,6,7,12-tetraazaperylene (tape). Tape was obtained from 1,1'-bis-2,7-naphthyridine by potassium promoted cyclization followed by oxidation with air. Mono-and dinuclear ruthenium(II) 1,6,7,12-tetraazaperylene complexes of the general formulas [Ru(L-L)(2)(tape)](PF6)(2), [1] (PF6)(2)-[5](PF6)(2), and [{Ru(L-L)(2)}(2)(mu-tape)](PF6)(4), [6](PF6)(4)-[10](PF6)(4), with{L-L = phen, bpy, dmbpy (4,4'-dimethyl-2,2'-bipyridine), dtbbpy (4,4'-ditertbutyl-2,2'-bipyridine) and tmbpy (4,4' 5,5'-tetramethyl-2,2'- bipyridine)}, respectively, were synthesized. The X-ray structures of tape center dot 2CHCl(3) and the mononuclear complexes [Ru(bpy)(2)(tape)](PF6)(2)center dot 0.5CH(3)CN center dot 0.5toluene, [Ru(dmbpy)(2)(tape)] (PF6)(2)center dot 2toluene and [Ru(dtbbpy)(2)(tape)](PF6)(2) center dot 3acetone center dot 0.5H(2)O were solved. The UV-vis absorption spectra and the electrochemical behavior of the ruthenium(II) tape complexes were explored and compared with the data of the analogous dibenzoeilatin (dbneil), 2,2'-bipyrimidine (bpym) and tetrapyrido [3,2-a:2',3'-c:3 '',2''-h:2''',3'''-j] phenazin (tpphz) species. Y1 - 2012 U6 - https://doi.org/10.1039/c2dt11805j SN - 1477-9226 VL - 41 IS - 9 SP - 2788 EP - 2797 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Träger, Juliane A1 - Klamroth, Tillmann A1 - Kelling, Alexandra A1 - Lubahn, Susanne A1 - Cleve, Ernst A1 - Mickler, Wulfhard A1 - Heydenreich, Matthias A1 - Müller, Holger A1 - Holdt, Hans-Jürgen T1 - Complexation of Palladium(II) with unsaturated Dithioethers a systematic development of highly selective ligands for solvent extraction JF - European journal of inorganic chemistry : a journal of ChemPubSoc Europe N2 - There is a demand for new and robust PdII extractants due to growing recycling rates. Chelating dithioethers are promising substances for solvent extraction as they form stable square-planar complexes with PdII. We have modified unsaturated dithioethers, which are known to coordinate PdII, and adapted them to the requirements of industrial practice. The ligands are analogues of 1,2-dithioethene with varying electron-withdrawing backbones and polar end-groups. The crystal structures of several ligands and their palladium complexes were determined as well as their electro- and photochemical properties, complex stability and behaviour in solution. Solvent extraction experiments showed the superiority of some of our ligands over conventionally used extractants in terms of their very fast reaction rates. With highly selective 1,2-bis(2-methoxyethylthio)benzene (4) it is possible to extract PdII from a highly acidic medium in the presence of other base and palladium-group metals. KW - Renewable resources KW - Palladium KW - Chelates KW - Ligand design KW - S li-gands Y1 - 2012 U6 - https://doi.org/10.1002/ejic.201101406 SN - 1434-1948 IS - 14 SP - 2341 EP - 2352 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Mickler, Wulfhard A1 - Bukowsky, Heinz A1 - Holdt, Hans-Jürgen T1 - Separation of Palladium(II) with immobilized Maleonitrile-Dithiocrown ethers N2 - Especially sulphur containing compounds are suitable for the separation of noble metals. 1,2-Dithioethenes are weak chelate-forming ligands and in the case of bis(methylthio)maleo-nitrile the donor power of both of the sulphur atoms is further decreased by the electron withdrawing effect of the cyanogroups. Crowned dithiomaleonitrile are macrocyclic chelate ligands which extract Pd(II) at sufficient rate in a very good yields. The synthesis of the immobilised ligands proceeds from the 2-allyloxy-1,2-propanediol forming the dicar-bon acid which is reduced to the diole. With the help of thionylchloride the dichloro compound is synthe-sized forming the macrocycle together with a dithiolate (1,2-disodium-1,2-dicyanethene-1,2-dithiolate, 1,2-disodium-4-methylbenzene-1,2-dithiolate) at high dilution conditions. The allylsubstituted crown ether is sillylated and the resulting alkoxysilane is immobilised onto activated silica gel. The extraction results with crown ethers are compared with that achieved with the help of substituted ß- diketones and 4-acyl-5-pyrazolones. By modification of the cavity of the macrocyclus the extraction rate increases from the acyclic compound through maleonitrile-dithio-21-crown-7, maleonitrile-dithio-15-crown-5 and maleonitrile-18-crown-6. The best results can be observed at the maleonitrile-dithio-12-crown-4. The rise of the function log D= f(log L) gives the composition of the extracted compounds as 1:1. The separa-tion is unsatisfactory in the case of Ag(I), Hg(II), Pt(II), Tl (I) and the most 3d-elements. Summarizing, a very good separation of palladium from the examined elements can be specified. Additional to the extraction experiments, as well as the crystal structures and by UV spectroscopy the for- mation constants of selected chelates were determined. Y1 - 2002 ER - TY - JOUR A1 - Kammer, Stefan A1 - Kelling, Alexandra A1 - Baier, Heiko A1 - Mickler, Wulfhard A1 - Dosche, Carsten A1 - Rurack, Knut A1 - Kapp, Andreas A1 - Lisdat, Fred A1 - Holdt, Hans-Jürgen T1 - 2,11-dialkylated 1,12-diazaperylene copper(I) complexes : first supramolecular column assemblies by pi-pi stacking between homoleptic tetrahedral metal complexes, exhibiting low-energy MLCT transitions N2 - 2,11-Dialkylated 1,12-diazaperylenes (alkyl = Me, Et, iPr) dmedap, detdap and dipdap have been synthesized by reductive cyclization of 3,3-dialkylated 1,1-biisoquinolines 3a-c, resulting in the first copper(I) complexes of a large- surface ligand. The new copper(I) complexes show low-energy MLCT absorptions unprecedented for bis(-diimin)copper(I) complexes. The solid structures of the complexes[Cu(dipdap)2]BF4·CH2Cl2·1.5H2O, [Cu(dipdap)2]OTf·CH2Cl2, [Cu(dipdap)2]I·C2H4Cl2·THF·2H2O, [Cu(dmedap)2]OTf and [Cu(dipdap)2]AQSO3·H2O (AQSO3 = sodium 9,10-dihydro-9,10-dioxo-2- anthracenesulfonate) are reported. In [Cu(dipdap)2]BF4·CH2Cl2·1.5H2O, each copper(I) complex cation interacts with two others by - stacking interactions forming a novel supramolecular column structural motif running along the crystallographic c axis. In the crystalline compound [Cu(dipdap)2]AQSO3·H2O, aggregation between two complex cations and two additional anions by - stacking interactions is observed, leading to a tetrameric assembly. Furthermore, the three complex compounds [Cu(L)2]BF4 (L = dmedap, detdap, dipdap) were tested for sensory applications in aqueous buffer solutions in electrochemical studies of the complex immobilized on glassy carbon electrodes. Y1 - 2009 UR - http://www3.interscience.wiley.com/journal/27721/home U6 - https://doi.org/10.1002/ejic.200900695 SN - 1434-1948 ER - TY - JOUR A1 - Brietzke, Thomas Martin A1 - Kelling, Alexandra A1 - Schilde, Uwe A1 - Mickler, Wulfhard A1 - Holdt, Hans-Jürgen T1 - Heterodinuclear Ruthenium(II) Complexes of the Bridging Ligand 1,6,7,12-Tetraazaperylene with Iron(II), Cobalt(II), Nickel(II), as well as Palladium(II) and Platinum(II) JF - Zeitschrift für anorganische und allgemeine Chemie N2 - The first heterodinuclear ruthenium(II) complexes of the 1,6,7,12-tetraazaperylene (tape) bridging ligand with iron(II), cobalt(II), and nickel(II) were synthesized and characterized. The metal coordination sphere in this complexes is filled by the tetradentate N,N-dimethyl-2,11-diaza[3.3](2,6)-pyridinophane (L-N4Me2) ligand, yielding complexes of the general formula [(L-N4Me2)Ru(mu-tape)M(L-N4Me2)](ClO4)(2)(PF6)(2) with M = Fe {[2](ClO4)(2)(PF6)(2)}, Co {[3](ClO4)(2)(PF6)(2)}, and Ni {[4](ClO4)(2)(PF6)(2)}. Furthermore, the heterodinuclear tape ruthenium(II) complexes with palladium(II)- and platinum(II)-dichloride [(bpy)(2)Ru(-tape)PdCl2](PF6)(2) {[5](PF6)(2)} and [(dmbpy)(2)Ru(-tape)PtCl2](PF6)(2) {[6](PF6)(2)}, respectively were also prepared. The molecular structures of the complex cations [2](4+) and [4](4+) were discussed on the basis of the X-ray structures of [2](ClO4)(4)MeCN and [4](ClO4)(4)MeCN. The electrochemical behavior and the UV/Vis absorption spectra of the heterodinuclear tape ruthenium(II) complexes were explored and compared with the data of the analogous mono- and homodinuclear ruthenium(II) complexes of the tape bridging ligand. KW - N ligands KW - Ruthenium KW - Structure elucidation KW - Charge transfer KW - Electrochemistry Y1 - 2016 U6 - https://doi.org/10.1002/zaac.201500645 SN - 0044-2313 SN - 1521-3749 VL - 642 SP - 8 EP - 13 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Kammer, Stefan A1 - Müller, Holger A1 - Grunwald, Nicolas A1 - Bellin, Anja A1 - Kelling, Alexandra A1 - Schilde, Uwe A1 - Mickler, Wulfhard A1 - Dosche, Carsten A1 - Holdt, Hans-Jürgen T1 - Supramolecular assemblies with honeycomb structures by pi-pi stacking of octahedral metal complexes of 1,12- diazaperylene N2 - Homoleptic Ni-II and Fe-II complexes of the "large-surface" phenanthroline-type ligand 1,12-diazaperylene (dap), [Ni(dap)(3)](BF4)(2) (1) and [Fe(dap)(3)](PF6)(2) (2), respectively, were synthesized. In the crystal structure the complex cation [M(dap)(3)](2+) (M = Ni, Fe) exhibits C-3 symmetry and interacts with three other cations by pi-pi stacking. It forms a new metalla-supramolecular assembly with a honeycomb structure containing nanochannels running parallel to the crystallographic c axis. Aggregation by pi-pi stacking between metal complexes of "large-surface" ligands should give new perspectives for inorganic supramolecular chemistry. Y1 - 2006 UR - http://www3.interscience.wiley.com/cgi-bin/jhome/27721/ U6 - https://doi.org/10.1002/ejic.200600092 SN - 1343-1948 ER - TY - BOOK A1 - Mickler, Wulfhard A1 - Holdt, Hans-Jürgen A1 - Bukowsky, Heinz T1 - Separation and Concentration of Pd(II) with Immobilized Maleonitrile-Dithiocrown Ethers N2 - Especially sulphur containing compounds are suitable for the separation of noble metals[ , ]. 1,2-Dithioethenes are weak chelate-forming ligands [ ]and in the case of bis(methylthio)maleonitrile[ ] the donor power of both of the sulphur atoms is further decreased by the electron withdrawing effect of the cyanogroups. Crowned dithiomaleonitrile are macrocyclic chelate ligands which extract Pd(II) at sufficient rate in a very good yields. The reason for that extraction behaviour is the fact that Pd(II) favours the square planar coordination geometry in opposite to the 3d- elements. The synthesis of the immobilized ligands proceeds from the 2-allyloxy-1,2-propanediol forming the dicarbon acid which is reduced to the diole. With the help of thionylchloride the dichloro compound is synthesized forming together with a dithiolate (1,2-disodium-1,2-dicyanethene-1,2-dithiolate, 1,2-disodium-4-methylbenzene-1,2-dithiolate [ ]) at high dilution conditions the macrocycle. Than the allysubstituted crown ether is sillylated and the resulting alkoxysilane is immobilised onto activated silca gel. The substituent forms in the same time a spacer should be modified in the future. By immobilisation at an inactive matrix the selectivity of the ligand should be applied for the accumulation of palladium from diluted solutions. The extraction was performed from nitric acid solution with a yield of 93% into a ligand solution (chloroform, kerosine). The extraction equilibrium is reached after 10 min. By atomic absorption spectroscopy the metal concentration in the aqueous phase was determined to calculate the extraction rate. By modification of the cavity of the macrocyclus the extraction rate increases from the acyclic compound through maleonitrile-dithio-21-crown-7, maleonitrile-dithio-15-crown-5 and maleonitrile-18-crown-6. The best results can be observed at the maleonitrile-dithio-12-crown-4. The rise of the function lg D= f(lg L) gives the composition of the extracted compounds as 1:1. The separation is unsatisfactory in the case of Ag(I), Hg(II), Pt(II), Tl (I) and the most 3d-elements. Also Ni(II) as a representative for the 3d-elements shows only separations coefficients of 1.43?103 . Summarizing, a very good separation of palladium from the examined elements can be specified. Additional to the extraction experiments, as well as the crystal structures and by UV spectroscopy the formation constants of selected chelates were determined. The observed order corresponds to that found by the extraction of palladium in the system water/chloroform. In the case of maleonitrile-dithio-15-crown-5 Ag(I) is endocyclic coordinated with all donor atoms of the macrocyclus. Already maleonitrile-dithio-18-crown-6 can include the silver cation into its greater cavity. In these cases a 1:1 complex is formed. A 1:2 sandwich structure was noticed only in the case of the smaller ligand maleonitrile- dithio-12-crown-4. Obviously, the formation of that structure is not favoured in the system water/chloroform from which can be explained the unfavourable extraction results. Y1 - 2001 ER - TY - JOUR A1 - Ast, Sandra A1 - Fischer, Tobias A1 - Müller, Holger A1 - Mickler, Wulfhard A1 - Schwichtenberg, Mathias A1 - Rurack, Knut A1 - Holdt, Hans-Jürgen T1 - Integration of the 1,2,3-Triazole "Click" Motif as a potent signalling element in metal ion responsive fluorescent probes JF - Chemistry - a European journal N2 - In a systematic approach we synthesized a new series of fluorescent probes incorporating donoracceptor (D-A) substituted 1,2,3-triazoles as conjugative -linkers between the alkali metal ion receptor N-phenylaza-[18]crown-6 and different fluorophoric groups with different electron-acceptor properties (4-naphthalimide, meso-phenyl-BODIPY and 9-anthracene) and investigated their performance in organic and aqueous environments (physiological conditions). In the charge-transfer (CT) type probes 1, 2 and 7, the fluorescence is almost completely quenched by intramolecular CT (ICT) processes involving charge-separated states. In the presence of Na+ and K+ ICT is interrupted, which resulted in a lighting-up of the fluorescence in acetonitrile. Among the investigated fluoroionophores, compound 7, which contains a 9-anthracenyl moiety as the electron-accepting fluorophore, is the only probe which retains light-up features in water and works as a highly K+/Na+-selective probe under simulated physiological conditions. Virtually decoupled BODIPY-based 6 and photoinduced electron transfer (PET) type probes 35, where the 10-substituted anthracen-9-yl fluorophores are connected to the 1,2,3-triazole through a methylene spacer, show strong ion-induced fluorescence enhancement in acetonitrile, but not under physiological conditions. Electrochemical studies and theoretical calculations were used to assess and support the underlying mechanisms for the new ICT and PET 1,2,3-triazole fluoroionophores. KW - charge transfer KW - click chemistry KW - electron transfer KW - fluorescent probes KW - metal ions Y1 - 2013 U6 - https://doi.org/10.1002/chem.201201575 SN - 0947-6539 VL - 19 IS - 9 SP - 2990 EP - 3005 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Schwarze, Thomas A1 - Mickler, Wulfhard A1 - Dosche, Carsten A1 - Flehr, Roman A1 - Klamroth, Tillmann A1 - Löhmannsröben, Hans-Gerd A1 - Saalfrank, Peter A1 - Holdt, Hans-Jürgen T1 - Systematic investigation of photoinduced electron transfer controlled by internal charge transfer and its consequences for selective PdCl2 coordination N2 - Fluoroionophores of fluorophore-spacer-receptor format were prepared for detection of PdCl2 by fluorescence enhancement. The fluorophore probes 1-13 consist of a fluorophore group, in alkyl spacer and a dithiomaleonitrile PdCl2 receptor. First, varying the length of the alkylene spacer (compounds 1-3) revealed, dominant through-space pathway for oxidative photoinduced electron transfer (PET) in CH2-bridged dithiomaleonitrile fluoroionophores. Second. fluorescent probes 4-9 containing two anthracene or pyrene fragments connected through CH2 bridges to the dithiomaleonitrile unit were synthesized. Modulation of the oxidation potential (E-Ox) through electron-withdrawing or -donating groups on the anthracene moiety regulates file thermodynamic driving force for oxidative PET (Delta G(PET)) in bis(anthrylmethylthio)maleonitriles and therefore the fluorescence quantum yields (Phi(f)), too. The new concept was confirmed and transferred to pyrenyl ligands, and fluorescence enhancements (FE) greater than 3.2 in the presence of PdCl2 were achieved by 7 and 8 (FE=5.4 and 5.2). Finally, for comparison, monofluorophore ligands 10-13 were synthesized. Y1 - 2010 UR - http://onlinelibrary.wiley.com/doi/10.1002/chem.200902281/pdf U6 - https://doi.org/10.1002/chem.200902281 SN - 0947-6539 ER - TY - JOUR A1 - Schwarze, Thomas A1 - Mickler, Wulfhard A1 - Dosche, Carsten A1 - Flehr, Roman A1 - Klamroth, Tillmann A1 - Löhmannsröben, Hans-Gerd A1 - Saalfrank, Peter A1 - Holdt, Hans-Jürgen T1 - Systematic investigation of photoinduced electron transfer controlled by internal charge transfer and its consequences for selective PdCl2 coordination N2 - Fluoroionophores of fluorophore-spacer-receptor format were prepared for detection of PdCl2 by fluorescence enhancement. The fluorescent probes 1-13 consist of a fluorophore group, an alkyl spacer and a dithiomaleonitrile PdCl2 receptor. First, varying the length of the alkylene spacer (compounds 1-3) revealed a dominant through-space pathway for oxidative photoinduced electron transfer (PET) in CH2-bridged dithiomaleonitrile fluoroionophores. Second, fluorescent probes 4-9 containing two anthracene or pyrene fragments connected through CH2 bridges to the dithiomaleonitrile unit were synthesized. Modulation of the oxidation potential (EOx) through electron-withdrawing or -donating groups on the anthracene moiety regulates the thermodynamic driving force for oxidative PET (GPET) in bis(anthrylmethylthio)maleonitriles and therefore the fluorescence quantum yields (f), too. The new concept was confirmed and transferred to pyrenyl ligands, and fluorescence enhancements (FE) greater than 3.2 in the presence of PdCl2 were achieved by 7 and 8 (FE=5.4 and 5.2). Finally, for comparison, monofluorophore ligands 10-13 were synthesized. Y1 - 2010 UR - http://www3.interscience.wiley.com/journal/26293/home SN - 0947-6539 ER - TY - JOUR A1 - Schwarze, Thomas A1 - Mueller, Holger A1 - Dosche, Carsten A1 - Klamroth, Tillmann A1 - Mickler, Wulfhard A1 - Kelling, Alexandra T1 - Luminescence detection of open-shell transition-metal ions by photoinduced electron transfer controlled by internal charge transfer of a receptor Y1 - 2007 UR - http://onlinelibrary.wiley.com/doi/10.1002/ange.200603992/pdf U6 - https://doi.org/10.1002/anie.200603992 ER -