@article{HahnTraegerHoldt2015,
  author    = {Hahn, Simone and Tr{\"a}ger, Juliane and Holdt, Hans-J{\"u}rgen},
  title     = {Solid-Phase extraction of Pt(IV) with Dialkyl-(hexane-1,6-diyl) phosphate modified merrifield resins from aqueous chloride media in column operations},
  series = {Separation and purification technology},
  volume    = {50},
  journal   = {Separation and purification technology},
  number    = {2},
  publisher = {Taylor \& Francis Group},
  address   = {Philadelphia},
  issn      = {0149-6395},
  doi       = {10.1080/01496395.2014.968264},
  pages     = {191 -- 206},
  year      = {2015},
  abstract  = {A series of three dialkyl phosphate resins with a Merrifield resin support was used to extract platinum from acidic media. In column operations total capacities of 85-130 mg/g were gained. The presence of palladium and rhodium results in the order: Pt(IV) > Pd(II) >> Rh(III). From a leach liquor gained from spent automotive catalysts metals forming anionic chloro complexes are co-extracted only to a small extent. However, in order to separate and enrich platinum a selective back-extraction can be done with a sodium thiocyanate solution. A second elution step with acidic thiourea leads to a mixed solution of palladium and rhodium.},
  language  = {en}
}
@article{BaierKellingHoldt2015,
  author    = {Baier, Heiko and Kelling, Alexandra and Holdt, Hans-J{\"u}rgen},
  title     = {PEPPSI-Effect on Suzuki-Miyaura Reactions Using 4,5-Dicyano-1,3-dimesitylimidazol-2-ylidene-Palladium Complexes: A Comparison between trans-Ligands},
  series = {European journal of inorganic chemistry : a journal of ChemPubSoc Europe},
  journal   = {European journal of inorganic chemistry : a journal of ChemPubSoc Europe},
  number    = {11},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1434-1948},
  doi       = {10.1002/ejic.201500010},
  pages     = {1950 -- 1957},
  year      = {2015},
  abstract  = {The PEPPSI (Pyridine Enhanced Precatalyst Preparation, Stabilization and Initiation) complexes 12-15 with the structure [PdCl2{(CN)(2)IMes}(3-R-py)] (12: R = H; 13: R = Cl; 14: R = Br; 15: R = CN) bearing the maleonitrile-based N-heterocyclic carbene (NHC) (CN)(2)IMes ({(CN)(2)IMes}: 4,5-dicyano-1,3-dimesitylimidazol-2-ylidene) were prepared. Solid state structures of 14 and 15 were obtained. Complexes 14 and 15 adopt a slightly distorted square-planar coordination geometry in the solid state with the substituted pyridine ligand trans to the NHC. Catalytic activities of precatalysts 12-15 were studied and subsequently compared to complexes [PdCl2{(CN)(2)IMes}(PPh3)] (4) and [PdCl(dmba){(CN)(2)IMes}] (5) recently reported by our group in the Suzuki-Miyaura reaction of various aryl halides and phenylboronic acid. Reactions using previously reported [PdCl2(IMes)(py)] (IMes: 1,3-dimesitylimidazol-2-ylidene) (1) were also carried out and their results contrasted to those involving 12-15, 4 and 5. Differences in initiation rates and the catalytically active species related to the seven complexes in regards to the throw away ligand were investigated. Poisoning experiments with mercury show that palladium nanoparticles are responsible for the catalytic activity.},
  language  = {en}
}
@article{AttenbergerMoussaBrietzkeetal.2015,
  author    = {Attenberger, Bianca and Moussa, Mehdi El Sayed and Brietzke, Thomas Martin and Vreshch, Volodimir and Holdt, Hans-J{\"u}rgen and Lescop, Christophe and Scheer, Manfred},
  title     = {Discrete Polymetallic Arrangements of Ag-I and Cu-I Ions Based on Multiple Bridging Phosphane Ligands and pi-pi Interactions},
  series = {European journal of inorganic chemistry : a journal of ChemPubSoc Europe},
  journal   = {European journal of inorganic chemistry : a journal of ChemPubSoc Europe},
  number    = {18},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1434-1948},
  doi       = {10.1002/ejic.201500445},
  pages     = {2934 -- 2938},
  year      = {2015},
  abstract  = {A simple and straightforward approach to new polymetallic Ag-I and Cu-I supramolecules is presented. The reaction of N,P,N,P,N ligand 2 with Ag-I ions affords a trimetallic complex bearing a triangular Ag-3 core; metallophilic interactions are stabilized by ligands that display a multiple bridging coordination mode as 10-electron donors. Heteroleptic polymetallic Ag-I and Cu-I complexes based on ligand 2 and the 1,12-diazaperylene (dape) ligand are obtained by an alternative molecular organization of the polymetallic arrays compared to that in homoleptic complexes of ligand 2.},
  language  = {en}
}
@article{TrautmannHoldt2015,
  author    = {Trautmann, Michael and Holdt, Hans-J{\"u}rgen},
  title     = {Separation of platinum and ruthenium by a sulphoxide modified polystyrene resin in laboratory column systems},
  series = {Separation and purification technology},
  volume    = {149},
  journal   = {Separation and purification technology},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1383-5866},
  doi       = {10.1016/j.seppur.2015.05.013},
  pages     = {279 -- 287},
  year      = {2015},
  abstract  = {The present study deals with the adsorption performance of fixed bed columns using powdered sulphoxide modified poly(styrene-co-divinylbenzene) (d(10) < 13 mu m, d(50) < 30 mu m, d(90) < 50 mu m) for the separation of platinum and ruthenium from hydrochloric acidic solutions containing both metals (c(Pt) = 20 mg/L, c(Ru) = 10 mg/L). The influence of hydrochloric acid concentration, temperature, flow rate, flow direction, redox potential and bed height on the breakthrough characteristics was examined. Platinum was separately adsorbed mainly induced by hydrochloric acid concentration and redox potential keeping platinum as Pt-IV and ruthenium as Ru-III. Ruthenium was separately adsorbed to 90\% essentially induced by hydrochloric acid concentration, temperature and redox potential keeping platinum as Pt-IV and ruthenium predominantly as Ru-IV. Experimental data at optimised separation conditions were fitted to different kinetic models (Thomas, Yoon-Nelson, Bohart-Adams, Wolborska) to characterise the fixed bed column behaviour. Adsorption of both metals was well described by Thomas and Yoon-Nelson model with correlation coefficients R-2 >= 0.95 whereas Bohart-Adams and Wolborska model were less suitable. (C) 2015 Elsevier B.V. All rights reserved.},
  language  = {en}
}
@article{SengeDahmsHoldtetal.2015,
  author    = {Senge, Mathias O. and Dahms, Katja and Holdt, Hans-J{\"u}rgen and Kelling, Alexandra},
  title     = {Porphyrin substituent regiochemistry, conformation and packing - the case of 5,10-diphenylporphyrin},
  series = {Zeitschrift f{\"u}r Naturforschung : B, Chemical sciences},
  volume    = {70},
  journal   = {Zeitschrift f{\"u}r Naturforschung : B, Chemical sciences},
  number    = {2},
  publisher = {De Gruyter},
  address   = {T{\"u}bingen},
  issn      = {0932-0776},
  doi       = {10.1515/znb-2014-0217},
  pages     = {119 -- 123},
  year      = {2015},
  abstract  = {5,10-Disubstituted porphyrins are more recent additions to the family of meso-substituted porphyrins. A crystallographic comparison of 5,10-diphenylporphyrin with the regioisomeric 5,15-disubstituted system reveals striking differences in their conformation. In the free base porphyrins the former uses mainly out-of-plane distortion to alleviate steric strain while in-plane core elongation predominates in the latter. In contrast, the structure of the Cu(II) complex is planar and forms strong p-p aggregates with very small lateral shifts. Macroscopically, the packing is similar to that of porphyrin sponges of the 5,10,15,20-tetraphenylporphyrin type.},
  language  = {en}
}
@article{SchwarzeRiemerEidneretal.2015,
  author    = {Schwarze, Thomas and Riemer, Janine and Eidner, Sascha and Holdt, Hans-J{\"u}rgen},
  title     = {A Highly K+-Selective Two-Photon Fluorescent Probe},
  series = {Chemistry - a European journal},
  volume    = {21},
  journal   = {Chemistry - a European journal},
  number    = {32},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {0947-6539},
  doi       = {10.1002/chem.201501473},
  pages     = {11306 -- 11310},
  year      = {2015},
  abstract  = {A highly K+-selective two-photon fluorescent probe for the in vitro monitoring of physiological K+ levels in the range of 1-100 mM is reported. The two-photon excited fluorescence (TPEF) probe shows a fluorescence enhancement (FE) by a factor of about three in the presence of 160 mM K+, independently of one-photon (OP, 430 nm) or two-photon (TP, 860 nm) excitation and comparable K+-induced FEs in the presence of competitive Na+ ions. The estimated dissociation constant (K-d) values in Na+-free solutions (K-d(OP)=(28 +/- 5) mM and K-d(TP)=(36 +/- 6) mM) and in combined K+/Na+ solutions (K-d(OP)=(38 +/- 8) mM and K-d(TP)=(46 +/- 25) mM) reflecting the high K+/Na+ selectivity of the fluorescent probe. The TP absorption cross-section (sigma(2PA)) of the TPEF probe+160 mMK(+) is 26 GM at 860 nm. Therefore, the TPEF probe is a suitable tool for the in vitro determination of K+.},
  language  = {en}
}
@article{MondalBehrensMatthesetal.2015,
  author    = {Mondal, Suvendu Sekhar and Behrens, Karsten and Matthes, Philipp R. and Sch{\"o}nfeld, Fabian and Nitsch, J{\"o}rn and Steffen, Andreas and Primus, Philipp-Alexander and Kumke, Michael Uwe and M{\"u}ller-Buschbaum, Klaus and Holdt, Hans-J{\"u}rgen},
  title     = {White light emission of IFP-1 by in situ co-doping of the MOF pore system with Eu3+ and Tb3+},
  series = {Journal of materials chemistry : C, Materials for optical and electronic devices},
  volume    = {18},
  journal   = {Journal of materials chemistry : C, Materials for optical and electronic devices},
  number    = {3},
  publisher = {Royal Society of Chemistry},
  address   = {Cambridge},
  issn      = {2050-7534},
  doi       = {10.1039/C4TC02919D},
  pages     = {4623 -- 4631},
  year      = {2015},
  abstract  = {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+.},
  language  = {en}
}
@article{MondalBehrensMatthesetal.2015,
  author    = {Mondal, Suvendu Sekhar and Behrens, Karsten and Matthes, Philipp R. and Sch{\"o}nfeld, Fabian and Nitsch, J{\"o}rn and Steffen, Andreas and Primus, Philipp-Alexander and Kumke, Michael Uwe and M{\"u}ller-Buschbaum, Klaus and Holdt, Hans-J{\"u}rgen},
  title     = {White light emission of IFP-1 by in situ co-doping of the MOF pore system with Eu3+ and Tb3+},
  series = {Journal of materials chemistry : C, Materials for optical and electronic devices},
  volume    = {3},
  journal   = {Journal of materials chemistry : C, Materials for optical and electronic devices},
  number    = {18},
  publisher = {Royal Society of Chemistry},
  address   = {Cambridge},
  issn      = {2050-7526},
  doi       = {10.1039/c4tc02919d},
  pages     = {4623 -- 4631},
  year      = {2015},
  language  = {en}
}
@article{MondalThomasHoldt2015,
  author    = {Mondal, Suvendu Sekhar and Thomas, Arne and Holdt, Hans-J{\"u}rgen},
  title     = {In situ synthesis of amide-imidate-imidazolate ligand and formation of metal-organic frameworks: Application for gas storage},
  series = {Microporous and mesoporous materials : zeolites, clays, carbons and related materials},
  volume    = {216},
  journal   = {Microporous and mesoporous materials : zeolites, clays, carbons and related materials},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1387-1811},
  doi       = {10.1016/j.micromeso.2015.01.049},
  pages     = {2 -- 12},
  year      = {2015},
  abstract  = {In this review article, we highlight the synthesis, structures and gas-sorption properties of a series of nine isostructural IFPs (IFP = Imidazolate Framework Potsdam) and two H-bonded networks. IFPs were synthesized by in situ partial hydrolysis of a 4,5-dicyanoimidazole under solvothermal conditions and hence an imidazolate-4-amide-5-imidate linker (C5H3N4O2) was generated, forming the metal -amide-imidate-imidazolateframeworks [M(C5H3N4O2)-R]. Varying R in the 2-substitued linker (R = Me, Cl, Br, Et, OMe and OEt) and metal centre (M2+ = zinc and cobalt) allowed the variation in channel diameter (4.2-03 angstrom) and a fine-tuning of the polarity and functionality of the channel walls of IFPs. Furthermore, we show that using ethyl or alkoxy substituted IFPs the flexible groups act as molecular gates for guest molecules. This allows highly selective CO2 sorption over Ny and CH4 gases. Moreover, during the synthesis of methoxy substituted IFPs (IFP-7 and -8), an imidazolate-4,5-diamide-2-olate linker (C5H4N4O3) formed in situ leads to the formation of a molecular building block (MBB) with a M-6 octahedron inscribed in a M-8 cube (M Zn2+ and Co2+). The MBBs connect by amide amide hydrogen bonds to a 3D robust supramolecular networks [Zn-14(C5H4N4O3)(12)(O) (OH)(2) (DMF)(4) denoted as 1 and 2, respectively, DMF = N,N'-dimethylformamide], which can be activated for N-2, CO2, CH4, and H-2 gas-sorption. (C) 2015 Elsevier Inc. All rights reserved.},
  language  = {en}
}
@article{MondalBehrensKellingetal.2015,
  author    = {Mondal, Suvendu Sekhar and Behrens, Karsten and Kelling, Alexandra and Nabein, Hans-Peter and Schilde, Uwe and Holdt, Hans-J{\"u}rgen},
  title     = {Two Cd-II/Co-II-Imidazolate Coordination Polymers: Syntheses, Crystal Structures, Stabilities, and Luminescent/Magnetic Properties},
  series = {Zeitschrift f{\"u}r anorganische und allgemeine Chemie},
  volume    = {641},
  journal   = {Zeitschrift f{\"u}r anorganische und allgemeine Chemie},
  number    = {11},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {0044-2313},
  doi       = {10.1002/zaac.201500526},
  pages     = {1991 -- 1997},
  year      = {2015},
  abstract  = {Cadmium(II) based 2D coordination polymer [Cd(L1)(2)(DMF)(2)] (1) (L1 = 4,5-dicyano-2-methylimidazolate, DMF = N,N'-dimethylformamide) and 2D cobalt(II)-imidazolate framework [Co(L3)(4)] (2) (L3 = 4,5-diamide-2-ethoxyimidazolate) were synthesized under solvothermal reaction conditions. The materials were characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, powder X-ray diffraction measurement (PXRD) and single-crystal X-ray diffraction. Compound 1 has hexacoordinate Cd-II ions and forms a zigzag chain-like coordination polymer structure, whereas compound 2 exhibits a 2D square grid type structure. The thermal stability analysis reveals that 2 showed an exceptional thermal stability up to 360 degrees C. Also, 2 maintained its fully crystalline integrity in boiling water as confirmed by PXRD. The solid state luminescent property of 1 was not observed at room temperature. Compound 2 showed an independent high spin central Co-II atom.},
  language  = {en}
}