TY  - JOUR
A1  - Zabel, André
A1  - Winter, Alette
A1  - Kelling, Alexandra
A1  - Schilde, Uwe
A1  - Strauch, Peter
T1  - Tetrabromidocuprates(II)-Synthesis, Structure and EPR
JF  - International journal of molecular sciences
N2  - Metal-containing ionic liquids (ILs) are of interest for a variety of technical applications, e.g., particle synthesis and materials with magnetic or thermochromic properties. In this paper we report the synthesis of, and two structures for, some new tetrabromidocuprates(II) with several “onium” cations in comparison to the results of electron paramagnetic resonance (EPR) spectroscopic analyses. The sterically demanding cations were used to separate the paramagnetic Cu(II) ions for EPR measurements. The EPR hyperfine structure in the spectra of these new compounds is not resolved, due to the line broadening resulting from magnetic exchange between the still-incomplete separated paramagnetic Cu(II) centres. For the majority of compounds, the principal g values (g|| and gK) of the tensors could be determined and information on the structural changes in the [CuBr4]2- anions can be obtained. The complexes have high potential, e.g., as ionic liquids, as precursors for the synthesis of copper bromide particles, as catalytically active or paramagnetic ionic liquids.
KW  - tetrabromidocuprate(II)
KW  - X-ray structure
KW  - electron paramagnetic resonance
KW  - copper(II)
Y1  - 2016
U6  - https://doi.org/10.3390/ijms17040596
VL  - 17
IS  - 4
PB  - MDPI
CY  - Basel
ER  - 
TY  - GEN
A1  - Zabel, André
A1  - Winter, Alette
A1  - Kelling, Alexandra
A1  - Schilde, Uwe
A1  - Strauch, Peter
T1  - Tetrabromidocuprates(II)-Synthesis, Structure and EPR
N2  - Metal-containing ionic liquids (ILs) are of interest for a variety of technical applications, e.g., particle synthesis and materials with magnetic or thermochromic properties. In this paper we report the synthesis of, and two structures for, some new tetrabromidocuprates(II) with several “onium” cations in comparison to the results of electron paramagnetic resonance (EPR) spectroscopic analyses. The sterically demanding cations were used to separate the paramagnetic Cu(II) ions for EPR measurements. The EPR hyperfine structure in the spectra of these new compounds is not resolved, due to the line broadening resulting from magnetic exchange between the still-incomplete separated paramagnetic Cu(II) centres. For the majority of compounds, the principal g values (g|| and gK) of the tensors could be determined and information on the structural changes in the [CuBr4]2- anions can be obtained. The complexes have high potential, e.g., as ionic liquids, as precursors for the synthesis of copper bromide particles, as catalytically active or paramagnetic ionic liquids.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 226 
KW  - tetrabromidocuprate(II)
KW  - X-ray structure
KW  - electron paramagnetic resonance
KW  - copper(II)
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-91470
ER  - 
TY  - JOUR
A1  - Zabel, Andre
A1  - Winter, Alette
A1  - Kelling, Alexandra
A1  - Schilde, Uwe
A1  - Strauch, Peter
T1  - Tetrabromidocuprates(II)-Synthesis, Structure and EPR
JF  - International journal of molecular sciences
N2  - Metal-containing ionic liquids (ILs) are of interest for a variety of technical applications, e.g., particle synthesis and materials with magnetic or thermochromic properties. In this paper we report the synthesis of, and two structures for, some new tetrabromidocuprates(II) with several "onium" cations in comparison to the results of electron paramagnetic resonance (EPR) spectroscopic analyses. The sterically demanding cations were used to separate the paramagnetic Cu(II) ions for EPR measurements. The EPR hyperfine structure in the spectra of these new compounds is not resolved, due to the line broadening resulting from magnetic exchange between the still-incomplete separated paramagnetic Cu(II) centres. For the majority of compounds, the principal g values (g|| and g(perpendicular to)) of the tensors could be determined and information on the structural changes in the [CuBr4](2-) anions can be obtained. The complexes have high potential, e.g., as ionic liquids, as precursors for the synthesis of copper bromide particles, as catalytically active or paramagnetic ionic liquids.
KW  - tetrabromidocuprate(II)
KW  - X-ray structure
KW  - electron paramagnetic resonance
KW  - copper(II)
Y1  - 2016
U6  - https://doi.org/10.3390/ijms17040596
SN  - 1422-0067
VL  - 17
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Winter, Alette
A1  - Zabel, Andre
A1  - Strauch, Peter
T1  - Tetrachloridocuprates(II)-Synthesis and Electron Paramagnetic Resonance (EPR) Spectroscopy
JF  - International journal of molecular sciences
N2  - Ionic liquids (ILs) on the basis of metal containing anions and/or cations are of interest for a variety of technical applications e.g., synthesis of particles, magnetic or thermochromic materials. We present the synthesis and the results of electron paramagnetic resonance (EPR) spectroscopic analyses of a series of some new potential ionic liquids based on tetrachloridocuprates(II), [CuCl4](2-), with different sterically demanding cations: hexadecyltrimethylammonium 1, tetradecyltrimethylammonium 2, tetrabutylammonium 3 and benzyltriethylammonium 4. The cations in the new compounds were used to achieve a reasonable separation of the paramagnetic Cu(II) ions for EPR spectroscopy. The EPR hyperfine structure was not resolved. This is due to the exchange broadening, resulting from still incomplete separation of the paramagnetic Cu(II) centers. Nevertheless, the principal values of the electron Zeemann tensor (g parallel to and g perpendicular to) of the complexes could be determined. Even though the solid substances show slightly different colors, the UV/Vis spectra are nearly identical, indicating structural changes of the tetrachloridocuprate moieties between solid state and solution. The complexes have a promising potential e.g., as high temperature ionic liquids, as precursors for the formation of copper chloride particles or as catalytic paramagnetic ionic liquids.
KW  - tetrachloridocuprate(II)
KW  - electron paramagnetic resonance
KW  - copper(II)
KW  - ionic liquid
Y1  - 2012
U6  - https://doi.org/10.3390/ijms13021612
SN  - 1661-6596
VL  - 13
IS  - 2
SP  - 1612
EP  - 1619
PB  - MDPI
CY  - Basel
ER  - 
TY  - GEN
A1  - Winter, Alette
A1  - Thiel, Kerstin
A1  - Zabel, André
A1  - Klamroth, Tillmann
A1  - Pöppl, Andreas
A1  - Kelling, Alexandra
A1  - Schilde, Uwe
A1  - Taubert, Andreas
A1  - Strauch, Peter
T1  - Tetrahalidocuprates(II) – structure and EPR spectroscopy
BT  - Part 2: tetrachloridocuprates(II)
N2  - We present and discuss the results of crystallographic and electron paramagnetic resonance (EPR) spectroscopic analyses of five tetrachloridocuprate(II) complexes to supply a useful tool for the structural characterisation of the [CuCl4]2− moiety in the liquid state, for example in ionic liquids, or in solution. Bis(benzyltriethylammonium)-, bis(trimethylphenylammonium)-, bis(ethyltriphenylphosphonium)-, bis(benzyltriphenylphosphonium)-, and bis(tetraphenylarsonium)tetrachloridocuprate(II) were synthesised and characterised by elemental, IR, EPR and X-ray analyses. The results of the crystallographic analyses show distorted tetrahedral coordination geometry of all [CuCl4]2− anions in the five complexes and prove that all investigated complexes are stabilised by hydrogen bonds of different intensities. Despite the use of sterically demanding ammonium, phosphonium and arsonium cations to obtain the separation of the paramagnetic Cu(II) centres for EPR spectroscopy no hyperfine structure was observed in the EPR spectra but the principal values of the electron Zeeman tensor, g∥ and g⊥, could be determined. With these EPR data and the crystallographic parameters we were able to carry out a correlation study to anticipate the structural situation of tetrachloridocuprates in different physical states. This correlation is in good agreement with DFT calculations.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 240 
KW  - electron-spin resonance
KW  - liquid-crystal precursors
KW  - copper(II) halide salts
KW  - ionic liquid
KW  - square planar
KW  - tetrachlorocuprate(II) salts
KW  - molecular-structure
KW  - magnetic-properties
KW  - paramagnetic-resonance
KW  - temperature phase
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-95012
SP  - 1019
EP  - 1030
ER  - 
TY  - JOUR
A1  - Winter, Alette
A1  - Thiel, Kerstin
A1  - Zabel, Andre
A1  - Klamroth, Tillmann
A1  - Poeppl, Andreas
A1  - Kelling, Alexandra
A1  - Schilde, Uwe
A1  - Taubert, Andreas
A1  - Strauch, Peter
T1  - Tetrahalidocuprates(II) - structure and EPR spectroscopy. Part 2: tetrachloridocuprates(II)
JF  - New journal of chemistry
N2  - We present and discuss the results of crystallographic and electron paramagnetic resonance (EPR) spectroscopic analyses of five tetrachloridocuprate(II) complexes to supply a useful tool for the structural characterisation of the [CuCl4](2-) moiety in the liquid state, for example in ionic liquids, or in solution. Bis(benzyltriethylammonium)-, bis(trimethylphenylammonium)-, bis(ethyltriphenylphosphonium)-, bis(benzyltriphenylphosphonium)-, and bis(tetraphenylarsonium) tetrachloridocuprate(II) were synthesised and characterised by elemental, IR, EPR and X-ray analyses. The results of the crystallographic analyses show distorted tetrahedral coordination geometry of all [CuCl4](2-) anions in the five complexes and prove that all investigated complexes are stabilised by hydrogen bonds of different intensities. Despite the use of sterically demanding ammonium, phosphonium and arsonium cations to obtain the separation of the paramagnetic Cu(II) centres for EPR spectroscopy no hyperfine structure was observed in the EPR spectra but the principal values of the electron Zeeman tensor, g(parallel to) and g(perpendicular to), could be determined. With these EPR data and the crystallographic parameters we were able to carry out a correlation study to anticipate the structural situation of tetrachloridocuprates in different physical states. This correlation is in good agreement with DFT calculations.
Y1  - 2014
U6  - https://doi.org/10.1039/c3nj01039b
SN  - 1144-0546
SN  - 1369-9261
VL  - 38
IS  - 3
SP  - 1019
EP  - 1030
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Wenzel, Barbara
A1  - Wehse, Burkhard
A1  - Schilde, Uwe
A1  - Strauch, Peter
T1  - 1,2-Dithioquadratato- und 1,2-Dithiooxalatoindate(III) = 1,2-dithiosquarato- and 1,2-dithiooxalatoindates(III)
N2  - Indium(III) chloride forms in water with potassium 1,2-dithiooxalate (dto) and potassium 1,2-dithiosquarate (dtsq) stable coordination compounds. Due to the higher bridging ability of the 1,2-dithiooxalate ligand in all cases only thiooxalate bridged binuclear complexes were found. From 1,2-dithioquadratate with an identical donor atom set mononuclear trischelates could be isolated. Five crystalline complexes, (BzlMe(3)N)(4)[(dto)(2)In(dto)In(dto)(2)] (1), (BzlPh(3)P)(4)[(dto)(2)In(dto)In(dto)(2)] (2), (BzlMe(3)N)(3)[In(dtsq)(3)] (3), (Bu4N)(3)[In(dtsq)(3)] (4) and (Ph4P)[In(dtsq)(2)(DMF)(2)] (5), have been isolated and characterized by X-ray analyses. Due to the type of the complex and the cations involved these compounds crystallize in different space groups with the following parameters: 1, monoclinic in P2(1)/c with a = 14.4035(5) Angstrom, b = 10.8141(5) Angstrom, c = 23.3698(9) Angstrom, beta = 124.664(2)degrees, and Z = 2; 2, triclinic in P (1) over bar with a = 11.3872(7) Angstrom, b = 13.6669(9) Angstrom, c = 17.4296(10) Angstrom, alpha = 88.883(5)degrees, beta = 96.763(1)degrees, gamma = 74.587(5)degrees, and Z = 1; 3, hexagonal in R3 with a = 20.6501(16) Angstrom, b = 20.6501(16) Angstrom, c = 19.0706(13) Angstrom and Z = 6; 4, monoclinic in P21/c with a = 22.7650(15) Angstrom, b = 20.4656(10) Angstrom, c = 14.4770(9) Angstrom, P
Y1  - 2004
UR  - http://www3.interscience.wiley.com/cgi-bin/jissue/109594384
ER  - 
TY  - JOUR
A1  - Vaskova, Zuzana
A1  - Kitanovski, Nives
A1  - Jaglicic, Zvonko
A1  - Strauch, Peter
A1  - Ruzickova, Zdenka
A1  - Valigura, Dusan
A1  - Koman, Marian
A1  - Kozlevcar, Bojan
A1  - Moncol, Jan
T1  - Synthesis and magneto-structural characterization of copper(II) nitrobenzoate complexes containing nicotinamide or methylnicotinamide ligands
JF  - Polyhedron : the international journal of inorganic and organometallic chemistry
N2  - Three new copper(II) 4-nitrobenzoato coordination compounds (4-NO(2)bz(-) = 4-nitrobenzoate anions) with N-methylnicotinamide (mna) [Cu(4-NO(2)bz)(2)(mna)(2)(H2O)] (1), [Cu(4-NO(2)bz)(2)(mu-mna)(H2O)](2) (2) and [Cu(mu-4-NO(2)bz)(2)(mna)](2) (3) were synthesized and characterized. Due to a comparison, additional two related compounds [Cu(3,5-(NO2)(2)bz)(2)(mna)(2)(H2O)] (4) (nia = nicotinamide, 3,5-(NO2)(2)bz(-) = 3,5-dinitrobenzoate anions) and [Cu(mu-2-NO(2)bz)(2)(mna)](2) (5) (2-NO(2)bz(-) = 2-nitrobenzoate anions) were isolated. The mononuclear compounds with mna 1 and nia 4 show CuO2N2O chromophores with the water molecule placed at the apex of the square pyramid. The square-pyramidal coordination sphere CuO3NO in 2 differs to CuO2N2O in 1 and 4. Differently, the water molecule is in 2 at the basal-plane, while two mna molecules serve also as bridges via N-py and 0-amido enabling a dinuclear molecular structure 1, 2 and 4 are paramagnetic though a dinuclear structure is seen in 2, while a clear-cut strong antiferromagnetic (AFM) coupling (2J -300 cm(-1)) is found for the compounds 3 and 5. (C) 2014 Elsevier Ltd. All rights reserved.
KW  - Copper(II)
KW  - Nicotinamide
KW  - N-methylnicotinamide
KW  - Crystal structure
KW  - Magnetic properties
Y1  - 2014
U6  - https://doi.org/10.1016/j.poly.2014.07.017
SN  - 0277-5387
VL  - 81
SP  - 555
EP  - 563
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Thiel, Kerstin
A1  - Zehbe, Rolf
A1  - Röser, Jerome
A1  - Strauch, Peter
A1  - Enthaler, Stephan
A1  - Thomas, Arne
T1  - A polymer analogous reaction for the formation of imidazolium and NHC based porous polymer networks
JF  - Polymer Chemistry
N2  - A polymer analogous reaction was carried out to generate a porous polymeric network with N-heterocyclic carbenes (NHC) in the polymer backbone. Using a stepwise approach, first a polyimine network is formed by polymerization of the tetrafunctional amine tetrakis(4-aminophenyl)methane. This polyimine network is converted in the second step into polyimidazolium chloride and finally to a polyNHC network. Furthermore a porous Cu(II)-coordinated polyNHC network can be generated. Supercritical drying generates polymer networks with high permanent surface areas and porosities which can be applied for different catalytic reactions. The catalytic properties were demonstrated for example in the activation of CO2 or in the deoxygenation of sulfoxides to the corresponding sulfides.
Y1  - 2013
U6  - https://doi.org/10.1039/c2py20947k
SN  - 1759-9954
VL  - 4
IS  - 6
SP  - 1848
EP  - 1856
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Thiel, Kerstin
A1  - Zehbe, Rolf
A1  - Roesner, Jerômé
A1  - Strauch, Peter
A1  - Enthaler, Stephan
A1  - Thomas, Arne
T1  - A polymer analogous reaction for the formation of imidazolium and NHC based porous polymer networks
N2  - A polymer analogous reaction was carried out to generate a porous polymeric network with N-heterocyclic carbenes (NHC) in the polymer backbone. Using a stepwise approach, first a polyimine network is formed by polymerization of the tetrafunctional amine tetrakis(4-aminophenyl)methane. This polyimine network is converted in the second step into polyimidazolium chloride and finally to a polyNHC network. Furthermore a porous Cu(II)-coordinated polyNHC network can be generated. Supercritical drying generates polymer networks with high permanent surface areas and porosities which can be applied for different catalytic reactions. The catalytic properties were demonstrated for example in the activation of CO2 or in the deoxygenation of sulfoxides to the corresponding sulfides.
Y1  - 2013
UR  - http://pubs.rsc.org/en/content/articlepdf/2013/py/c2py20947k
U6  - https://doi.org/10.1039/C2PY20947K
ER  - 
TY  - GEN
A1  - Thiel, Kerstin
A1  - Zehbe, Rolf
A1  - Roeser, Jerômé
A1  - Strauch, Peter
A1  - Enthaler, Stephan
A1  - Thomas, Arne
T1  - A polymer analogous reaction for the formation of imidazolium and NHC based porous polymer networks
N2  - A polymer analogous reaction was carried out to generate a porous polymeric network with N-heterocyclic carbenes (NHC) in the polymer backbone. Using a stepwise approach, first a polyimine network is formed by polymerization of the tetrafunctional amine tetrakis(4-aminophenyl)methane. This polyimine network is converted in the second step into polyimidazolium chloride and finally to a polyNHC network. Furthermore a porous Cu(II)-coordinated polyNHC network can be generated. Supercritical drying generates polymer networks with high permanent surface areas and porosities which can be applied for different catalytic reactions. The catalytic properties were demonstrated for example in the activation of CO2 or in the deoxygenation of sulfoxides to the corresponding sulfides.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 243 
KW  - covalent organic framework
KW  - n-heterocyclic carbenes
KW  - carbon-dioxide
KW  - intrinsic microporosity
KW  - heterogeneous catalysis
KW  - sulfoxides
KW  - reduction
KW  - complex
KW  - system
KW  - transformation
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-95118
SP  - 1848
EP  - 1856
ER  - 
TY  - JOUR
A1  - Thiel, Kerstin
A1  - Klamroth, Tillmann
A1  - Strauch, Peter
A1  - Taubert, Andreas
T1  - On the interaction of ascorbic acid and the tetrachlorocuprate ion [CuCl4](2-) in CuCl nanoplatelet formation from an ionic liquid precursor (ILP)
JF  - Physical chemistry, chemical physics : a journal of European Chemical Societies
N2  - The formation of CuCl nanoplatelets from the ionic liquid precursor (ILP) butylpyridinium tetrachlorocuprate [C4Py](2)[CuCl4] using ascorbic acid as a reducing agent was investigated. In particular, electron paramagnetic resonance (EPR) spectroscopy was used to evaluate the interaction between ascorbic acid and the Cu(II) ion before reduction to Cu(I). EPR spectroscopy suggests that the [CuCl4](2-) ion in the neat IL is a distorted tetrahedron, consistent with DFT calculations. Addition of ascorbic acid leads to the removal of one chloride from the [CuCl4](2-) anion, as shown by DFT and the loss of symmetry by EPR. DFT furthermore suggests that the most stable adduct is formed when only one hydroxyl group of the ascorbic acid coordinates to the Cu(II) ion.
Y1  - 2011
U6  - https://doi.org/10.1039/c1cp20648f
SN  - 1463-9076
VL  - 13
IS  - 30
SP  - 13537
EP  - 13543
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Strehmel, Veronika
A1  - Rexhausen, Hans
A1  - Strauch, Peter
A1  - Strehmer, Bernd
T1  - Temperature dependence of interactions between stable piperidine-1-yloxyl derivatives and a semicrystalline ionic liquid
N2  - The stable 2,2,6,6-tetramethylpiperidine-1-yloxyl and its derivatives with hydrogen-bond-forming (-OH, -OSO3H), anionic (-OSO3- bearing K+ or [K(18-crown-6)](+) as counter ion), or cationic (-N+-(CH3)(3) bearing I-, BF4-, PF6- or N- (SO2CF3)(2) as counter ion) substituents are investigated in 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide over a wide temperature range. The temperature dependence of the viscosity of the ionic liquid is well described by the Vogel-Fulcher-Tammann equation. Interestingly, the temperature dependence of the rotational correlation time of the spin probes substituted with either a hydrogen-bond-forming group or an ionic substituent can be described using the Stokes-Einstein equation. In contrast, the temperature dependence of the rotational correlation time of the spin probe without an additional substituent at the 4-position to the nitroxyl group does not follow this trend. The activation energy for the mobility of the unsubstituted spin probe, determined from an Arrhenius plot of the spin-probe mobility in the ionic liquid above the melting temperature, is comparable with the activation energy for the viscous flow of the ionic liquid, but is higher for spin probes bearing an additional substituent at the 4-position. Quantum chemical calculations of the spin probes using the 6-31G+d method give information about the rotational volume of the spin probes and the spin density at the nitrogen atom of the radical structure as a function of the substituent at the spin probes in the presence and absence of a counter ion. The results of these calculations help in understanding the effect of the additional substituent on the experimentally determined isotropic hyperfine coupling constant.
Y1  - 2010
UR  - http://www3.interscience.wiley.com/cgi-bin/jhome/72514732/
U6  - https://doi.org/10.1002/cphc.200900977
SN  - 1439-4235
ER  - 
TY  - JOUR
A1  - Strehmel, Veronika
A1  - Rexhausen, Hans
A1  - Strauch, Peter
T1  - 2,2,6,6-Tetramethylpiperidine-1-yloxyl bound to the imidazolium ion by an acetamido group for investigation of ionic liquids
N2  - New spin probes bearing the 2,2,6,6-tetramethylpiperidine-1-yloxyl covalently bound to the imidazolium ion via a methylene spacer and an amide group are synthesized. If the anion is bis(trifluoromethylsulfonylimide) instead of iodide, the new spin probe has a similar structure as that of an ionic liquid. Nevertheless, the new spin probes are useful tools to investigate ionic liquids.
Y1  - 2010
UR  - http://www.sciencedirect.com/science/journal/00404039
U6  - https://doi.org/10.1016/j.tetlet.2009.11.124
SN  - 0040-4039
ER  - 
TY  - JOUR
A1  - Strehmel, Veronika
A1  - Rexhausen, Hans
A1  - Strauch, Peter
T1  - Influence of imidazolium bis(trifluoromethylsulfonylimide)s on the rotation of spin probes comprising ionic and hydrogen bonding groups
N2  - The influence of the alkyl chain length in 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonylimide)s is studied to explore the rotation of piperidine-1-yloxyl derivatives substituted with either hydrogen bonding hydroxy group or ionic substituents, such as the cationic trimethylammonium or the anionic sulfate group placed at the 4 position. Structural variation of the ionic liquids results in differences of their viscosity influencing the rotation of the spin probes. The size of the average rotational correlation times of the spin probes dissolved in the ionic liquids depends further on the additional substituent in 4-position at these spin probes. The rotational correlation time exhibits a linear dependence on the ionic liquid viscosity in the case of the spin probe forming hydrogen bonding with the ionic liquids. In contrast to this, a deviation from the Stokes-Einstein behavior is found in the case of rotation of the charged spin probes in the 1-alkyl-3-methylimidazolium bis( trifluoromethylsulfonylimide) s substituted with a longer alkyl chain. This effect may be explained by phase separation on a molecular level between the charged part of the ionic liquid and the longer alkyl chains bound at the imidazolium ion. Although the neutral and the cationic spin probes show only a slight dependence between ionic liquid structure variation and the hyperfine coupling constants, structural effects cause changes in the hyperfine coupling constants in the case of the anionic spin probes. These probes strongly interact with the imidazolium ion.
Y1  - 2010
UR  - http://www.rsc.org/Publishing/Journals/CP/index.asp
U6  - https://doi.org/10.1039/B920586a
SN  - 1463-9076
ER  - 
TY  - JOUR
A1  - Strehmel, Veronika
A1  - Rexhausen, Hans
A1  - Strauch, Peter
T1  - New spin probes starting from 4-amino-2,2,6,6-tetramethylpiperidine-1-yloxyl
JF  - Tetrahedron letters
N2  - This Letter describes four new 4-trimethylammonio-2,2,6,6-tetramethylpiperidine-1-yloxyls bearing camphorsulfonate, triflate, tosylate, or lactate as counter ions. These spin probes were made by anion metathesis of 4-trimethylammonio-2,2,6,6-tetramethylpiperidine-1-yloxyl iodide using the corresponding silver salts. The latter is made by the alkylation of 4-amino-2,2,6,6-tetramethylpiperidine-1-yloxyl. Furthermore, the Letter gives an improved synthetic way to 4-sulfonamido-2,2,6,6-tetramethylpiperidine-1-yloxyl using chlorosulfuric acid trimethylsilylester and 4-amino-2,2,6,6-tetramethylpiperidine-1-yloxyl. All the spin probes are highly interesting for the investigation of ionic liquids.
KW  - Nitroxides
KW  - Spin probes
KW  - ESR spectroscopy
KW  - Ionic liquids
Y1  - 2012
U6  - https://doi.org/10.1016/j.tetlet.2012.01.063
SN  - 0040-4039
VL  - 53
IS  - 13
SP  - 1587
EP  - 1591
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Strehmel, Veronika
A1  - Berdzinski, Stefan
A1  - Strauch, Peter
A1  - Hoffmann-Jacobsen, Kerstin
A1  - Strehmel, Bernd
T1  - Investigation of molecular solvents and ionic liquids with a dual probe
JF  - Zeitschrift für physikalische Chemie : international journal of research in physical chemistry and chemical physics
N2  - A dual probe was investigated by UV-Vis, fluorescence, and ESR spectroscopy. It comprises the pyrene chromophore and the paramagnetic 2,2,6,6-tetramethylpiperidinyl-N-oxyl radical that are covalently linked together via an ester bridge. The dual probe was used to investigate molecular solvents of different polarity as well as ionic liquids bearing either imidazolium or pyrrolidinium cations and various anions, such as bis(trifluoromethylsulfonyl)imide, tetrafluoroborate, tris(pentafluoroethyl)trifluorophosphate, or dicyanamide. The dual probe does not show solvatochromism that is typical for some pyrenes. Furthermore, the dual probe is considerable less mobile compared to 2,2,6,6-tetramethylpiperidinyl-N-oxyl (TEMPO) without additional substituent as detected by ESR spectroscopy. This is caused by the bulky pyrenyl substituent bound at the dual probe resulting in a reduced mobility of the dual probe.
KW  - Ionic Liquid
KW  - Fluorescence
KW  - ESR
KW  - Molecular Probe
Y1  - 2014
U6  - https://doi.org/10.1515/zpch-2014-0453
SN  - 0942-9352
VL  - 228
IS  - 2-3
SP  - 155
EP  - 169
PB  - De Gruyter
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Strauch, Peter
A1  - Neumann, Mike
A1  - Kelling, Alexandra
A1  - Schilde, Uwe
T1  - Bis(1,2-dithiosquarato)nickelates(II): Synthesis, Structure, EPR and Thermal Behavior
JF  - Acta chimica Slovenica
N2  - 1,2-Dithiosquaratonickelates are available by direct synthesis from metal salts with dipotassium-1,2-dithiosquarate and the appropriate counter cations. The synthesis and characterization, including mass spectrometry, of a series 1,2-dithiosquaratonickelates(II), [Ni(dtsq)(2)](2-), with several "onium" cations is reported and the X-ray structures of two diamagnetic complexes, (HexPh(3)P)(2)[Ni(dtsq)(2)] and (BuPh3P)(2)[Ni(dtsq)(2)] with sterically demanding counter ions are presented. The diamagnetic nickel complexes have been doped as host lattices with traces of Cu(II) to measure EPR for additional structural information. The thermal behavior of this series is studied by thermogravimetry and differential thermal analysis (TG/DTA). The thermolysis in air as well as under nitrogen atmosphere of these complexes results in nickel oxide nano-particles in all cases, which are characterized by X-ray powder diffraction.
KW  - 1,2-Dithiosquarate,1,2-Dithiosquaratonickelate
KW  - X-ray structure
KW  - TG/DTA
KW  - Nickel oxide
KW  - EPR spectroscopy
Y1  - 2015
SN  - 1318-0207
SN  - 1580-3155
VL  - 62
IS  - 2
SP  - 288
EP  - 296
PB  - Drustvo
CY  - Ljubljana
ER  - 
TY  - JOUR
A1  - Strauch, Peter
A1  - Kossmann, Alexander
A1  - Kelling, Alexandra
A1  - Schilde, Uwe
T1  - EPR on bis(1,2-dithiosquarato)cuprate(II) in the bis(1,2-dithiosquarato)nickelate(II) host lattice - structure and spectroscopy
JF  - Chemical papers
N2  - EPR spectroscopy is a well suited analytical tool to monitor the electronic situation around paramagnetic metal centres as copper(II) and therefore the structural influences on the paramagnetic ion. 1,2-Dithiosquaratometalates are available by direct synthesis from metal salts with dipotassium-1,2-dithiosquarate and the appropriate counter cations. Synthesis and characterisation of bis(benzyltributylammonium)1,2-dithiosquaratonickelate(II), (BzlBu(3)N)(2)[Ni(dtsq)(2)], and bis(benzyltributylammonium)1,2-dithiosquaratocuprate(II), (BzlBu(3)N)(2)[Cu(dtsq)(2)], with benzyltributylammonium as the counter ion is reported and the X-ray structures of two complexes, (BzlBu(3)N)(2)[Ni(dtsq)(2)] and (BzlBu(3)N)(2)[Cu(dtsq)(2)], are presented. Both complexes, crystallising in the monoclinic space group P2(1)/c, are isostructural with only small differences in the coordination sphere due to the different metal ions. The diamagnetic nickel complex is therefore well suited as a host lattice for the paramagnetic Cu(II) complex to measure EPR for additional structural information. (c) 2015 Institute of Chemistry, Slovak Academy of Sciences
KW  - 1,2-dithiosquarate
KW  - 1,2-dithiosquaratometalate
KW  - X-ray structure
KW  - EPR spectroscopy
Y1  - 2016
U6  - https://doi.org/10.1515/chempap-2015-0154
SN  - 0366-6352
SN  - 1336-9075
VL  - 70
SP  - 61
EP  - 68
PB  - De Gruyter
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Sonnenburg, Kirstin
A1  - Adelhelm, Philipp
A1  - Antonietti, Markus
A1  - Smarsly, Bernd
A1  - Nöske, Robert
A1  - Strauch, Peter
T1  - Synthesis and characterization of SiC materials with hierarchical porosity obtained by replication techniques
N2  - Porous silicon carbide monoliths were obtained using the infiltration of preformed SiO2 frameworks with appropriate carbon precursors such as mesophase pitch. The initial SiO2 monoliths possessed a hierarchical pore system, composed of an interpenetrating bicontinuous macropore structure and 13 nm mesopores confined in the macropore walls. After carbonization, further heat treatment at ca. 1400 degrees C resulted in the formation of a SiC-SiO2 composite, which was converted into a porous SiC monolith by post-treatment with ammonium fluoride solution. The resulting porous SiC featured high crystallinity, high chemical purity and showed a surface area of 280 m(2) g(-1) and a pore volume of 0.8 ml g(-1)
Y1  - 2006
UR  - http://pubs.rsc.org/en/Content/ArticleLanding/2006/CP/b604819f
U6  - https://doi.org/10.1039/B604819F
ER  -