TY  - JOUR
A1  - Awad, Duha Jawad
A1  - Conrad, Franziska
A1  - Koch, Andreas
A1  - Schilde, Uwe
A1  - Poeppl, Andreas
A1  - Strauch, Peter
T1  - 1,10-phenanthroline-dithiolate mixed ligand transition metal complexes : synthesis, characterization and EPR spectroscopy
N2  - A series of new N2S2 mixed ligand transition metal complexes, where N-2 is phenanthroline and S-2 is 1,2- dithiooxalate (dto) or 1,2-dithiosquarate (dtsq), has been synthesized and characterized. IR spectra reveal that the 1,2- dithiolate ligands are coordinated via the sulfur atoms forming a N2S2 coordination sphere. The copper(II) complex [Cu(phen)(dto)] was studied by EPR spectroscopy as a diamagnetically diluted powder. The diamagnetic dilution resulted from doping of the copper complex into the isostructural host lattice of the nickel complex [Ni(phen)(dto)]. The electronic situation in the frontier orbitals of the copper complex calculated from the experimental data is compared to the results of EHT and DFT calculations. Furthermore, one side product, chlorobis(1,10-phenanthroline)copper(I) ethanol solvate hydrate [(phen)(2)CuCl]center dot C2H5OH center dot H2O, was formed by a reduction process and characterized by X-ray diffraction. In the crystal packing one-dimensional columns of dimers are formed, stabilized by significant pi-pi interactions.
Y1  - 2010
UR  - http://www.sciencedirect.com/science/journal/00201693
U6  - https://doi.org/10.1016/j.ica.2010.01.021
SN  - 0020-1693
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  - Awad, Duha Jawad
A1  - Conrad, Franziska
A1  - Koch, Andreas
A1  - Friedrich, Alwin
A1  - Poeppl, Andreas
A1  - Strauch, Peter
T1  - 2,2'-Bipyridin-1,2-dithiolat Gemischtligand-Komplexe : Systhese, Charakterisierung und EPR-Spektroskopie
N2  - A series of new 2 2'-bipyridine/1 2-dithiolate transition metal complexes has been synthesised and characterised As 1,2-dithiolate ligands 1,2 dithiooxalate (dto) and 1 2-dithiosquarate (dtsq) were used It follows from the IR spectra that the multidentate dithiolate ligands coordinate exclusively via their sulfur atoms forming an MN2S2 coordination sphere The central metal ions (M) are Cu2+ Ni2+ Pd2+ Pt2+, and Zn2+ The complex [Cu-II(bpy)(dto)] could be studied by EPR spectroscopy and was measured as powder diamagnetically diluted in the isostructural [Ni-II(bpy)(dto)] host structure The spin density contribution calculated from the experimental parameters is compared with the electronic situation in the frontier orbitals namely in the semi occupied SOMO of the copper complex derived from quantum chemical calculations on different levels (EHT and DFT)
Y1  - 2010
UR  - http://www.znaturforsch.com/b.htm
SN  - 0932-0776
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  - Awad, Duha Jawad
A1  - Schilde, Uwe
A1  - Strauch, Peter
T1  - 4,4 '-Bis(tert-butyl)-2,2 '-bipyridinedichlorometal(II) - Synthesis, structure and EPR spectroscopy
JF  - Inorganica chimica acta : the international inorganic chemistry journal
N2  - Due to the better solubility of the 4,4'-substituted bipyridine ligand a series of 4,4'0-bis(tert-butyl)-2,2'-bipyridinedichlorometal(II) complexes, [M(tbbpy)Cl(2)], with M = Cu, Ni, Zn, Pd, Pt was synthesised and characterised. The blue copper complex 4,4'-bis(tert-butyl)-2,2'-bipyridinedichlorocopper(II) was isolated in two different polymorphic forms, as prisms 1 with a solvent inclusion and solvent-free as needles 2. Both structures were determined by X-ray structure analysis. They crystallise in the monoclinic space group P2(1)/c with four molecules in the unit cell, but with different unit cells and packing motifs. Whereas in the prisms 1, with the unit cell parameters a = 12.1613(12), b = 10.6363(7), c = 16.3074(15) angstrom, eta = 94.446(8)degrees, the packing is dominated by intra-and intermolecular hydrogen bonds, in the needles 2, with a = 7.738(1), b = 18. 333(2), c = 13.291(3) angstrom, beta = 97.512(15)degrees, only intramolecular hydrogen bonds appear and the complex molecules are arranged in columns which are stabilised by p-p-stacking interactions. In both complexes the copper has a tetrahedrally distorted coordination sphere. These copper complexes were also studied by EPR spectroscopy in solution, as frozen glass and diamagnetically diluted powder with the analogue [Pd(tbbpy)Cl(2)] as host lattice.
KW  - 4,4 '-Bis(tert-butyl)-2,2 '-bipyridine
KW  - X-ray structure
KW  - EPR
KW  - Copper(II)
KW  - Transition metals
Y1  - 2011
U6  - https://doi.org/10.1016/j.ica.2010.08.035
SN  - 0020-1693
VL  - 365
IS  - 1
SP  - 127
EP  - 132
PB  - Elsevier
CY  - Lausanne
ER  - 
TY  - GEN
A1  - König, Jana
A1  - Kelling, Alexandra
A1  - Schilde, Uwe
A1  - Strauch, Peter
T1  - [µ2-O,O′,Oʺ,Oʺ′-Bis(1,2-dithiooxalato-S,S′)nickel(II)]bis[-O,O′-bis(1,2-dithiooxalato-S,S′)-nickel(II)pentaquaholmium(III)]hydrate, [Ho2Ni3(dto)6(H2O)10]
N2  - Planar bis(1,2-dithiooxalato)nickelate(II), [Ni(dto)]2− reacts in aqueous solutions with lanthanide ions (Ln3+) to form pentanuclear, hetero-bimetallic complexes of the general composition [{Ln(H2O)n}2{Ni(dto)2}3]·xH2O. (n = 4 or 5; x = 9–12). The complex [{Ho(H2O)5}2{Ni(dto)2}3]·10H2O, Ho2Ni3, was synthesized and characterized by single crystal X-ray structure analysis and powder diffraction. The Ho2Ni3 complex crystallizes as monoclinic crystals in the space group P21/c. The channels and cavities, appearing in the crystal packing of the complex molecules, are occupied by a varying amount of non-coordinated water molecules.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 360 
KW  - lanthanides
KW  - holmium(III)
KW  - 1,2-dithiooxalate
KW  - crystal structure
KW  - nickel(II)
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-400598
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  - 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  - 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  - Neumann, Mike
A1  - Noeske, Robert
A1  - Bach, Grete
A1  - Glaubauf, Thomas
A1  - Bartoszek, Michael
A1  - Strauch, Peter
T1  - A procedure for rapid determination of the silicon content in plant materials
JF  - Zeitschrift für Naturforschung : B, Chemical sciences
N2  - An efficient, reliable and low-cost procedure to determine the silicon content in plant material is presented which allows to monitor the agricultural aspects like growth and yield. The presented procedure consists of a hydrochloric acid pre-treatment and a subsequent thermal oxidation. The method is compared to other processes like dissolution in hydrofluoric acid combined with ICP OES, energy-dispersive X-ray fluorescence spectroscopy (EDXRF) or aqua regia treatment.
KW  - Silica Determination
KW  - Silicon Content
KW  - Plant Material
Y1  - 2011
SN  - 0932-0776
VL  - 66
IS  - 3
SP  - 289
EP  - 294
PB  - De Gruyter
CY  - Tübingen
ER  - 
TY  - JOUR
A1  - Kozlevcar, Bojan
A1  - Mate, Elizabeta
A1  - Jaglicic, Zvonko
A1  - Glažar, Lea
A1  - Golobic, Amalija
A1  - Strauch, Peter
A1  - Moncol, Jan
A1  - Kitanovski, Nives
A1  - èegedin, Primož
T1  - A small methanoato ligand in the structural differentiation of copper(II) complexes
N2  - Several copper(II) methanoato complexes, namely mononuclear [Cu(O2CH)(2)(2-mpy)(2)] (1) (2-mpy = 2- methylpyridine), binuclear [Cu-2(mu-O2CH)(4)(2-mpy)(2)] (2), and the polynuclear {[Cu(mu-O2CH)(2)(2-mpy)(2)] [Cu-2(mu- O2CH)(4)]}(n) (3) and {Na-2[Cu(mu-O2CH)(2)(O2CH)(2)][Cu-2(mu-O2CH)(4)]}(n) (4), have been synthesized. The mononuclear complex I is formed by two asymmetric chelate methanoate anions and two 2-methylpyridine molecules, giving a highly distorted 'elongated octahedral' coordination sphere. Complex I decomposes outside the mother-liquid, transforming into a regular isolated binuclear paddle-wheel complex 2 with four intra-binuclear bridging methanoates and two axial 2-mpy ligands. The polynuclear complex 3 is formed of alternate mononuclear and binuclear building blocks resembling the central cores of I and 2, but with significant differences, especially for the methanoates of the mononuclear units. The oxygen atom of the mononuclear unit in the octahedral axial position in 3 is simultaneously coordinated to the axial position of the binuclear paddle-wheel central core, thus enabling a chain type of structure. A chain of alternate mononuclear and binuclear building blocks, as in the neutral compound 3. are found as well in the ionic polymeric compound 4, though two types of bridges are found in 4, while there is only one type in 3. Namely, the axial position of the octahedral mononuclear unit in 4 is occupied by the methanoate oxygen atom that is already a part of the binuclear paddle-wheel unit, while one equatorial methanoate from the mononuclear unit serves as a triatomic bridge to the axial position of the binuclear building block. A very strong antiferromagnetic interaction is found for all the complexes with the paddle-wheel building blocks [Cu-2(mu-O2CH)(4)] 2-4 (-2J = 444-482 cm(-1)), attributed to the methanoate intra-binuclear bridges. On the other hand, this strong antiferromagnetism, found already at room temperature, reduces the intensity of the EPR S = 1 spin signals reported for the isolated paddle-wheel complex 2. For the polymeric 3, only the spin S = 1/2 signals are found in the EPR spectra, and they are assigned to the mononuclear building blocks. No signals with a clear origin are however seen in the room temperature EPR spectrum of the polymeric analogue 4, only the S = 1/2 signals in the low temperature spectra. This feature is suggested to be due to a specific influence between the adjacent S = 1 (binuclear) and S = 1/2 (mononuclear) species via their bridges.
Y1  - 2009
UR  - http://www.sciencedirect.com/science/journal/02775387
U6  - https://doi.org/10.1016/j.poly.2009.05.066
SN  - 0277-5387
ER  - 
TY  - JOUR
A1  - Abouserie, Ahed
A1  - Zehbe, Kerstin
A1  - Metzner, Philipp
A1  - Kelling, Alexandra
A1  - Günter, Christina
A1  - Schilde, Uwe
A1  - Strauch, Peter
A1  - Körzdörfer, Thomas
A1  - Taubert, Andreas
T1  - Alkylpyridinium Tetrahalidometallate Ionic Liquids and Ionic Liquid Crystals: Insights into the Origin of Their Phase Behavior
JF  - European journal of inorganic chemistry : a journal of ChemPubSoc Europe
N2  - Six N-alkylpyridinium salts [CnPy](2)[MCl4] (n = 4 or 12 and M = Co, Cu, Zn) were synthesized, and their structure and thermal properties were studied. The [C4Py](2)[MCl4] compounds are monoclinic and crystallize in the space group P2(1)/n. The crystals of the longer chain analogues [C12Py](2)[MCl4] are triclinic and crystallize in the space group P (1) over bar. Above the melting temperature, all compounds are ionic liquids (ILs). The derivatives with the longer C12 chain exhibit liquid crystallinity and the shorter chain compounds only show a melting transition. Consistent with single-crystal analysis, electron paramagnetic resonance spectroscopy suggests that the [CuCl4](2-) ions in the Cu-based ILs have a distorted tetrahedral geometry.
KW  - Ionic liquids
KW  - Alkylpyridinium salts
KW  - Structure elucidation
KW  - Phase transitions
Y1  - 2017
U6  - https://doi.org/10.1002/ejic.201700826
SN  - 1434-1948
SN  - 1099-0682
SP  - 5640
EP  - 5649
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Abouserie, Ahed
A1  - Zehbe, Kerstin
A1  - Metzner, Philipp
A1  - Kelling, Alexandra
A1  - Günter, Christina
A1  - Schilde, Uwe
A1  - Strauch, Peter
A1  - Körzdörfer, Thomas
A1  - Taubert, Andreas
T1  - Alkylpyridinium Tetrahalidometallate Ionic Liquids and Ionic Liquid Crystals: Insights into the Origin of Their Phase Behavior
JF  - European journal of inorganic chemistry : a journal of ChemPubSoc Europe
N2  - Six N-alkylpyridinium salts [CnPy](2)[MCl4] (n = 4 or 12 and M = Co, Cu, Zn) were synthesized, and their structure and thermal properties were studied. The [C4Py](2)[MCl4] compounds are monoclinic and crystallize in the space group P2(1)/n. The crystals of the longer chain analogues [C12Py](2)[MCl4] are triclinic and crystallize in the space group P (1) over bar. Above the melting temperature, all compounds are ionic liquids (ILs). The derivatives with the longer C12 chain exhibit liquid crystallinity and the shorter chain compounds only show a melting transition. Consistent with single-crystal analysis, electron paramagnetic resonance spectroscopy suggests that the [CuCl4](2-) ions in the Cu-based ILs have a distorted tetrahedral geometry.
KW  - Ionic liquids
KW  - Alkylpyridinium salts
KW  - Structure elucidation
KW  - Phase transitions
Y1  - 2017
U6  - https://doi.org/10.1002/ejic.201700826
SN  - 1434-1948
SN  - 1099-0682
SP  - 5640
EP  - 5649
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Fischer, Sabrina
A1  - Schmidt, Johannes
A1  - Strauch, Peter
A1  - Thomas, Arne
T1  - An anionic microporous polymer network prepared by the polymerization of weakly coordinating anions
JF  - Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition
KW  - borates
KW  - conjugated microporous polymers
KW  - covalent organic frameworks
KW  - ion exchange
KW  - weakly coordinating ions
Y1  - 2013
U6  - https://doi.org/10.1002/anie.201303045
SN  - 1433-7851
SN  - 1521-3773
VL  - 52
IS  - 46
SP  - 12174
EP  - 12178
PB  - Wiley-VCH
CY  - Weinheim
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  - Kozlevcar, Bojan
A1  - Odlazek, Darja
A1  - Golobic, Amalija
A1  - Pevec, Andrej
A1  - Strauch, Peter
A1  - Segedin, Primoz
T1  - Complexes with lignin model compound vanillic acid : two different carboxylate ligands in the same dinuclear tetracarboxylate complex [Cu-2(C8H7O4)(2)(O2CCH3)(2)(CH3OH)(2)]
N2  - Two copper(II) coordination compounds with vanillic acid C8H8O4 (1), namely [Cu- 2(C8H7O4)(2)(O2CCH3)(2)(CH3OH)(2)] (2) and [Cu-2(C8H7O4)(4)(H2O2)(2)] (3), were synthesized and characterized. Single crystals of 1-3 were obtained and their crystal structures determined. The structure of 2 shows dinuclear cage structure of copper acetate hydrate type, however with two different carboxylates, acetates and vanillic acid anions,. respectively. Both bridging anions are in pairs in trans orientation. Methanol molecules are apically coordinated (Cu-O7 2.160(2) angstrom), fulfilling square-pyramidal coordination sphere around both copper ions. The compound 2 decomposes outside mother-liquid (yielding [Cu-2(C8H7O4)(2)(O2CCH3)(2)(H2O)(2)] (2a)) with the removal of methanol, but without significant change of the dicopper tetracarboxylate cage structure, as noticed by mu(eff) 1.48 BM for 2a. Similar was found also in the X-band EPR spectra with three signals H-z1, H-perpendicular to 2 and H-z2 in the region from 0 to 600 mT. The structure of free vanillic acid 1 is composed of dimeric units of two molecules, connected by two parallel hydrogen bonds between carboxylate group of each other (O1-H(...)O2 2.642(3) angstrom), while the structure of 3 is of [Cu-2(O2CCH3)(4)(H2O)(2)] type. Interestingly, an additional signal in the EPR spectra of 3 is found at 80 mT (H- perpendicular to 1) at 298 and at 116 K, next to three signals H-z1, H-perpendicular to 2 and H-z2.
Y1  - 2006
UR  - http://www.sciencedirect.com/science/journal/02775387
U6  - https://doi.org/10.1016/j.poly.2005.08.031
SN  - 0277-5387
ER  - 
TY  - JOUR
A1  - Kozlevcar, Bojan
A1  - Gamez, Patrick
A1  - de Gelder, Rene
A1  - Jaglicic, Zvonko
A1  - Strauch, Peter
A1  - Kitanovski, Nives
A1  - Reedijk, Jan
T1  - Counterion and solvent effects on the primary coordination sphere of copper(II) Bis(3,5-dimethylpyrazol-1-yl)acetic acid coordination compounds
JF  - European journal of inorganic chemistry : a journal of ChemPubSoc Europe
N2  - Four copper(II) coordination compounds with the neutral ligand bis(3,5-dimethylpyrazol-1-yl)acetic acid (Hbdmpza, C(12)H(16)N(4)O(2)) and its anionic form (bdmpza(-)), namely [Cu(Hbdmpza)(2)](HSO(4))(2) (1), [Cu(Hbdmpza)(2)]Cl(2) (2), [Cu(bdmpza)(2)](CH(3)COOH)(H(2)O) (3), and [Cu(bdmpza)(2)][Cu(2)(O(2)CCH(3))(4)] (4) have been synthesized starting from different metal salts. All the compounds have been fully characterized by physical and analytical methods. In addition, a single-crystal XRD analysis revealed the 3D structure of 1, which exhibits tridentate, vicinal N,N,O-coordination of two symmetry-related Hbdmpza ligands in an elongated octahedral arrangement with four equatorial nitrogen atoms and two axial oxygen atoms. The neutral carboxylic moiety acts as a hydrogen-bond donor to a HSO(4)(-) counterion. The two hydrogensulfates form a unique hydrogen-bonded pair (HSO(4)(-))(2) with very short O center dot center dot center dot O distances (2.59 angstrom) bridged between adjacent [Cu(HL)(2)](2+) coordination units. Also a short O center dot center dot center dot O contact (2.54 angstrom) is present between the C-OH and an 0 of a hydrogensulfate. A characteristic IR C=O vibration is observed at 1700 cm(-1) for 1 and 2, whereas the v(as)(O(2)C) vibration is present at 1650 cm(-1) for 3 and 4. These IR data strongly suggest the presence of Hbdmpza ligands in 1 and 2 and the deprotonated form bdmpza- in 3 and 4. A mononuclear coordination unit [CuL(2)], as proven for 1 by X-ray diffraction, is also proposed for the other compounds 2-4. In compound 4, an additional dinuclear [Cu(2)(O(2)CCH(3))(4)] neutral coordination unit is present, as deduced from the vibration bands v(as)(O(2)C) at 1600 cm(-1) and v(s)(O(2)C) at 1420 cm(-1), which are typical of a carboxylate function, and from the two-species analysis of the chi(M)T(T) curve of the magnetic susceptibility data (2J = -322 cm(-1)). Also, the EPR spectra recorded at different temperatures agree with this structure.
KW  - Copper
KW  - Coordination modes
KW  - Hydrogen bonds
KW  - Counterions
KW  - Solvent effects
Y1  - 2011
U6  - https://doi.org/10.1002/ejic.201100410
SN  - 1434-1948
IS  - 24
SP  - 3650
EP  - 3655
PB  - Wiley-Blackwell
CY  - Malden
ER  - 
TY  - JOUR
A1  - Kozlevcar, Bojan
A1  - Golobic, Amalija
A1  - Strauch, Peter
T1  - Dynamic pseudo Jahn-Teller distortion in a compressed octahedral CuO6 complex
JF  - Polyhedron : the international journal of inorganic and organometallic chemistry
N2  - The crystal structure of cis-[Cu(C8H7O3)(2)(H2O)(2)] (115 K data) reveals bidentate vanillinate ions coordinated via methoxy and deprotonated hydroxy oxygen atoms and water molecules in a distorted octahedral CuO6 chromophore. A cis orientation of the ligands enables two non-identical O(methoxy)-Cu-O(water) coordination axes (2.354(l) + 2.163(1); 2.151(1) + 2.020(1) angstrom), and the third shortest O(hydroxy)-Cu-O(hydroxy) axis (1.919(1) + 1.914(1) angstrom). This 115 K coordination sphere differs importantly to the one obtained from the 293 K data of the same compound, where two long 0(methoxy)-Cu-O(water) axes are of the same length, and only minor changes at the short 0(hydroxy)-Cu-O(hydroxy) axis are noticed. An axial symmetry of the complex with an inverse g(1.2)(g(perpendicular to)) > g(3)(g(parallel to)) pattern is observed in the temperature range from 298 to 180 K. A further decrease of temperature reveals gradual changes from axial to rhombic symmetry (g(1) > g(2) > g(3)) that is reversible. A mean-square displacement amplitude (MDSA) analysis reveals a disorder in the Cu-O(methoxy) bonds, but not in the other metal-ligand Cu-O(hydroxy) and Cu-O(water) bonds at 293 and 115 K. The disorder is significantly weaker in the 115 K structure. The MSDA analysis and the structural-EPR agreement show vibrational disorder in two coordination axes, due to the cis conformation of the complex with two 0(methoxy)-Cu-O(water) axes.
KW  - copper
KW  - vanillin
KW  - Jahn-Teller distortion
KW  - MSDA
KW  - cis
KW  - EPR
Y1  - 2006
U6  - https://doi.org/10.1016/j.poly.2006.04.009
SN  - 0277-5387
VL  - 25
IS  - 15
SP  - 2824
EP  - 2828
PB  - Elsevier
CY  - Oxford
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  - 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  -