SrAu 0.5 Pt 0.5 and CaAu 0.5 Pt 0.5 , Analogues to the Respective Ba Compound, but Featuring Pure... more SrAu 0.5 Pt 0.5 and CaAu 0.5 Pt 0.5 , Analogues to the Respective Ba Compound, but Featuring Purely Intermetallic Behavior.-The title compounds are obtained from mixtures of the corresponding elements (Ta tube, Ar, 1223 K, 2 d) and characterized by single crystal XRD, ESCA, electrical resistivity, and magnetic measurements. They crystallize isotypically with BaAu0.5Pt0.5 in the space group Cmcm with Z = 4 (CrB-type structure). The structure contains prisms of alkaline earth metal atoms which share their rectangular faces in such a way that infinite rows of prisms result which are centered by transition metal atoms forming a zigzag chain. The rows are condensed forming layers of trigonal prisms. The compounds are poor metallic conductors and show diamagnetic behavior.-(
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Acta Crystallographica Section A Foundations and Advances, 2021
Transition metal oxides are a platform for a plethora of exotic electronic phases where multiple ... more Transition metal oxides are a platform for a plethora of exotic electronic phases where multiple degrees of freedom of correlated delectrons, together with an underlying lattice topology, are at play. The ground states of these systems are governed by a subtle balance of relevant electronic parameters such as Coulomb repulsion, bandwidth, and crystal fields. 4d ruthenium compounds have been playing a significant role in providing novel electronic states such as unconventional superconductivity, metal-insulator transition, and quantum magnetism.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Rb2Mn3O4 is synthesized by the azide/nitrate route from a stoichiometric mixture of RbN3, RbNO3, ... more Rb2Mn3O4 is synthesized by the azide/nitrate route from a stoichiometric mixture of RbN3, RbNO3, and MnO (773 K, 30 h) and by solid state reaction of Rb2O and MnO (773 K, 130 h).
The synthesis of pristinen on-planar nanographenes (NGs) via ac yclodehydrofluorinations trategy ... more The synthesis of pristinen on-planar nanographenes (NGs) via ac yclodehydrofluorinations trategy is reported and the creationo fh ighly strained systemsv ia aluminaassisted CÀFb onda ctivation is shown. Steric hindrance could execute an alternative coupling program leadingt o rare octagon formation offering access to elusive non-classical NGs. The combination of two alternative ways of folding could lead to the formation of various3DNGobjects, resembling the Japanese art of origami.T he powero ft he presented "origami" approachi sp rovedb yt he assembly of 12 challenging nanographenes that are p-isoelectronic to planar hexabenzocoronene but forced out of planarity.
Lemon-yellow single crystals of Eu 2 [SiO 4 ] were obtained by reaction of elemental europium wit... more Lemon-yellow single crystals of Eu 2 [SiO 4 ] were obtained by reaction of elemental europium with Eu 2 O 3 in the presence of SiO 2 carried out in evacuated silica ampoules at 1373 K for 48 h followed by constant cooling to room temperature with K per hour. Eu 2 [SiO ] crystallizes at room temperature in the larnite-type structure of β-Ca 2 [SiO 4 ] (monoclinic, P2 1 /n) with parameters a = 565.02(5), b = 709.15(6), c = 975.84(8) pm, β = 92.614(3)° for Z = 4. At 452 K it undergoes a reversible phase transition to an incommensurate structure similar to the isotypic compounds Sr 2 [SiO 4 ] and K 2 [SeO 4 ]. The phase transition energy was determined to 0.54(2) J•g-1 by DSC measurements and temperature dependent birefringence measurements show that the phase transition exhibits a significant hysteresis. Refinements of the structure of Eu 2 [SiO 4 ] based on single crystal X-ray diffraction data show that the high temperature modification crystallizes in the orthorhombic space group Pnma(α00)0ss with a = 710.16(6), b = 566.93(5), c = 977.13(8) pm and an incommensurate modulation along [100] with a modulation vector t = [0.293(4), 0, 0]. Eu 2 [SiO 4 ] exhibits a bright yellow photoluminescence and its permittivity increases above 300 K substantially. Magnetic susceptibility and EPR measurements show that Eu 2 [SiO 4 ] becomes ferromagnetic below 7 K with a g factor of 1.993.
Zeitschrift für anorganische und allgemeine Chemie, 2019
The new compound Cs 6 Mn 2 O 6 was synthesized via the azide/nitrate route. According to single-c... more The new compound Cs 6 Mn 2 O 6 was synthesized via the azide/nitrate route. According to single-crystal X-ray analysis (P1;
The complex iridium oxide Na3Ir3O8 with a B-site ordered spinel structure was synthesized in sing... more The complex iridium oxide Na3Ir3O8 with a B-site ordered spinel structure was synthesized in single crystalline form, where the chiral hyper-kagome lattice of Ir ions, as observed in the spin-liquid candidate Na4Ir3O8, was identified. The average valence of Ir is 4.33+ and, therefore, Na3Ir3O8 can be viewed as a doped analogue of the hyper-kagome spin liquid with Ir(4+). The transport measurements, combined with the electronic structure calculations, indicate that the ground state of Na3Ir3O8 is a low carrier density semi-metal. We argue that the semi-metallic state is produced by a competition of the molecular orbital splitting of t2g orbitals on Ir3 triangles with strong spin-orbit coupling inherent to heavy Ir ions.
† Electronic supplementary information (ESI) available: Synthesis and characterization of 2, crys... more † Electronic supplementary information (ESI) available: Synthesis and characterization of 2, crystal description of 1 and 2. CCDC 975935 and 975934 for structures 1 and 2. For ESI and crystallographic data in CIF or other electronic format see
Zeitschrift für anorganische und allgemeine Chemie, 2008
Reaction of alkali metal ozonides (KO 3 , RbO 3 and CsO 3) with [18]crown-6 in liquid ammonia yie... more Reaction of alkali metal ozonides (KO 3 , RbO 3 and CsO 3) with [18]crown-6 in liquid ammonia yields compounds of the composition M([18]crown-6)O 3 • x NH 3 with M ϭ K (x ϭ 2), Rb (x ϭ 1) and Cs (x ϭ 8). The large intermolecular distance between adjacent radical anions in these compounds leads to almost ideal paramagnetic behavior according to Curie's law. Discrepancies concerning the structure of the ozonide anions in the K and Cs com
Na 5 Cu 3 O 6 , a new member of one dimensional charge ordered chain cuprates, was synthesized vi... more Na 5 Cu 3 O 6 , a new member of one dimensional charge ordered chain cuprates, was synthesized via the azide/nitrate route by reacting NaN 3 , NaNO 3 and CuO. According to single crystal Xray analysis, one dimensional 1 ∞ CuO 2 nchains built up from planar, edge-sharing CuO 4 squares are a dominant feature of the crystal structure. From the analysis of the Cu-O bond lengths we find that the system forms a Wigner lattice. The commensurate charge order allows to explicitly assign the valence states of either +2 or +3 to each copper atom resulting in a repetition according to Cu 2+-Cu 3+-Cu 2+-Cu 2+-Cu 3+-Cu 2+. Following the theoretical analysis of the previously synthesized compounds Na 3 Cu 2 O 4 and Na 8 Cu 5 O 10, the magnetic susceptibility was expected to show a large dimer gap. Surprisingly, this is not the case. To resolve this puzzle, we show that the magnetic couplings in this compound are strongly affected by excitations across the Wigner charge gap. By including these contributions, which are distinct from conventional superexchange in Mott-insulators, we obtain a quantitative satisfying theoretical description of the magnetic susceptibility data.
Zeitschrift für Kristallographie - New Crystal Structures, 2009
iource of material fallowing a published prescription [1], 1.55 mL of Me3SiNEt2 vere added dropwi... more iource of material fallowing a published prescription [1], 1.55 mL of Me3SiNEt2 vere added dropwise to a solution of 0.72 g TaCls in 20 mL dithyl ether/toluene mixture (1:3). The orange solution was alowed to stir at room temperature for 24 h. Afterwards, the solvent vas removed in vacuum, which leads to a ruby red solid. This olid was dissolved in dried pentane and stored at 0 °C for 12 h,-30 °C for 24 h and-65 °C for 24 h. A broken piece of a red, neelle-shaped crystal, which was selected from the cold mother soluion, was mounted using a nylon loop for X-ray diffraction.
Zeitschrift für Kristallographie - New Crystal Structures, 2009
added, bronze needles of the partially oxidized Ki .7s[Pt(CN)4] • 1.5H 2 0 form [2], Discussion I... more added, bronze needles of the partially oxidized Ki .7s[Pt(CN)4] • 1.5H 2 0 form [2], Discussion In monoclinic Pt(CN>4 • 2H2O the Pt-C distances of 2.010 Â, in good agreement with the literature [3,4], are similar to the short Pt-O distances of 2.017 Â. Therefore the platinum is octahedrally coordinated by four cyanide ligands and two oxygen atoms of the water molecules. This arrangement is similar to the potassium tetracyanoplatinate halogenides K2[Pt(CN)4X2] (X = CI, Br, I) [S] with the water molecules replacing the halogene atoms. The Pt atoms, as the center of the octahedra, are forming a face centered arrangement, and the Pt(CN)4-2H2O octahedra are linked to each other by hydrogen bonds between the nitrogen atoms and the H2O molecules of neighbouring complexes forming a 3D network, with Ν-Η distances of 1.713 and 1.743 Â and the N-H-O distances of 2.631 and 2.602 Â.
SrAu 0.5 Pt 0.5 and CaAu 0.5 Pt 0.5 , Analogues to the Respective Ba Compound, but Featuring Pure... more SrAu 0.5 Pt 0.5 and CaAu 0.5 Pt 0.5 , Analogues to the Respective Ba Compound, but Featuring Purely Intermetallic Behavior.-The title compounds are obtained from mixtures of the corresponding elements (Ta tube, Ar, 1223 K, 2 d) and characterized by single crystal XRD, ESCA, electrical resistivity, and magnetic measurements. They crystallize isotypically with BaAu0.5Pt0.5 in the space group Cmcm with Z = 4 (CrB-type structure). The structure contains prisms of alkaline earth metal atoms which share their rectangular faces in such a way that infinite rows of prisms result which are centered by transition metal atoms forming a zigzag chain. The rows are condensed forming layers of trigonal prisms. The compounds are poor metallic conductors and show diamagnetic behavior.-(
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Acta Crystallographica Section A Foundations and Advances, 2021
Transition metal oxides are a platform for a plethora of exotic electronic phases where multiple ... more Transition metal oxides are a platform for a plethora of exotic electronic phases where multiple degrees of freedom of correlated delectrons, together with an underlying lattice topology, are at play. The ground states of these systems are governed by a subtle balance of relevant electronic parameters such as Coulomb repulsion, bandwidth, and crystal fields. 4d ruthenium compounds have been playing a significant role in providing novel electronic states such as unconventional superconductivity, metal-insulator transition, and quantum magnetism.
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Rb2Mn3O4 is synthesized by the azide/nitrate route from a stoichiometric mixture of RbN3, RbNO3, ... more Rb2Mn3O4 is synthesized by the azide/nitrate route from a stoichiometric mixture of RbN3, RbNO3, and MnO (773 K, 30 h) and by solid state reaction of Rb2O and MnO (773 K, 130 h).
The synthesis of pristinen on-planar nanographenes (NGs) via ac yclodehydrofluorinations trategy ... more The synthesis of pristinen on-planar nanographenes (NGs) via ac yclodehydrofluorinations trategy is reported and the creationo fh ighly strained systemsv ia aluminaassisted CÀFb onda ctivation is shown. Steric hindrance could execute an alternative coupling program leadingt o rare octagon formation offering access to elusive non-classical NGs. The combination of two alternative ways of folding could lead to the formation of various3DNGobjects, resembling the Japanese art of origami.T he powero ft he presented "origami" approachi sp rovedb yt he assembly of 12 challenging nanographenes that are p-isoelectronic to planar hexabenzocoronene but forced out of planarity.
Lemon-yellow single crystals of Eu 2 [SiO 4 ] were obtained by reaction of elemental europium wit... more Lemon-yellow single crystals of Eu 2 [SiO 4 ] were obtained by reaction of elemental europium with Eu 2 O 3 in the presence of SiO 2 carried out in evacuated silica ampoules at 1373 K for 48 h followed by constant cooling to room temperature with K per hour. Eu 2 [SiO ] crystallizes at room temperature in the larnite-type structure of β-Ca 2 [SiO 4 ] (monoclinic, P2 1 /n) with parameters a = 565.02(5), b = 709.15(6), c = 975.84(8) pm, β = 92.614(3)° for Z = 4. At 452 K it undergoes a reversible phase transition to an incommensurate structure similar to the isotypic compounds Sr 2 [SiO 4 ] and K 2 [SeO 4 ]. The phase transition energy was determined to 0.54(2) J•g-1 by DSC measurements and temperature dependent birefringence measurements show that the phase transition exhibits a significant hysteresis. Refinements of the structure of Eu 2 [SiO 4 ] based on single crystal X-ray diffraction data show that the high temperature modification crystallizes in the orthorhombic space group Pnma(α00)0ss with a = 710.16(6), b = 566.93(5), c = 977.13(8) pm and an incommensurate modulation along [100] with a modulation vector t = [0.293(4), 0, 0]. Eu 2 [SiO 4 ] exhibits a bright yellow photoluminescence and its permittivity increases above 300 K substantially. Magnetic susceptibility and EPR measurements show that Eu 2 [SiO 4 ] becomes ferromagnetic below 7 K with a g factor of 1.993.
Zeitschrift für anorganische und allgemeine Chemie, 2019
The new compound Cs 6 Mn 2 O 6 was synthesized via the azide/nitrate route. According to single-c... more The new compound Cs 6 Mn 2 O 6 was synthesized via the azide/nitrate route. According to single-crystal X-ray analysis (P1;
The complex iridium oxide Na3Ir3O8 with a B-site ordered spinel structure was synthesized in sing... more The complex iridium oxide Na3Ir3O8 with a B-site ordered spinel structure was synthesized in single crystalline form, where the chiral hyper-kagome lattice of Ir ions, as observed in the spin-liquid candidate Na4Ir3O8, was identified. The average valence of Ir is 4.33+ and, therefore, Na3Ir3O8 can be viewed as a doped analogue of the hyper-kagome spin liquid with Ir(4+). The transport measurements, combined with the electronic structure calculations, indicate that the ground state of Na3Ir3O8 is a low carrier density semi-metal. We argue that the semi-metallic state is produced by a competition of the molecular orbital splitting of t2g orbitals on Ir3 triangles with strong spin-orbit coupling inherent to heavy Ir ions.
† Electronic supplementary information (ESI) available: Synthesis and characterization of 2, crys... more † Electronic supplementary information (ESI) available: Synthesis and characterization of 2, crystal description of 1 and 2. CCDC 975935 and 975934 for structures 1 and 2. For ESI and crystallographic data in CIF or other electronic format see
Zeitschrift für anorganische und allgemeine Chemie, 2008
Reaction of alkali metal ozonides (KO 3 , RbO 3 and CsO 3) with [18]crown-6 in liquid ammonia yie... more Reaction of alkali metal ozonides (KO 3 , RbO 3 and CsO 3) with [18]crown-6 in liquid ammonia yields compounds of the composition M([18]crown-6)O 3 • x NH 3 with M ϭ K (x ϭ 2), Rb (x ϭ 1) and Cs (x ϭ 8). The large intermolecular distance between adjacent radical anions in these compounds leads to almost ideal paramagnetic behavior according to Curie's law. Discrepancies concerning the structure of the ozonide anions in the K and Cs com
Na 5 Cu 3 O 6 , a new member of one dimensional charge ordered chain cuprates, was synthesized vi... more Na 5 Cu 3 O 6 , a new member of one dimensional charge ordered chain cuprates, was synthesized via the azide/nitrate route by reacting NaN 3 , NaNO 3 and CuO. According to single crystal Xray analysis, one dimensional 1 ∞ CuO 2 nchains built up from planar, edge-sharing CuO 4 squares are a dominant feature of the crystal structure. From the analysis of the Cu-O bond lengths we find that the system forms a Wigner lattice. The commensurate charge order allows to explicitly assign the valence states of either +2 or +3 to each copper atom resulting in a repetition according to Cu 2+-Cu 3+-Cu 2+-Cu 2+-Cu 3+-Cu 2+. Following the theoretical analysis of the previously synthesized compounds Na 3 Cu 2 O 4 and Na 8 Cu 5 O 10, the magnetic susceptibility was expected to show a large dimer gap. Surprisingly, this is not the case. To resolve this puzzle, we show that the magnetic couplings in this compound are strongly affected by excitations across the Wigner charge gap. By including these contributions, which are distinct from conventional superexchange in Mott-insulators, we obtain a quantitative satisfying theoretical description of the magnetic susceptibility data.
Zeitschrift für Kristallographie - New Crystal Structures, 2009
iource of material fallowing a published prescription [1], 1.55 mL of Me3SiNEt2 vere added dropwi... more iource of material fallowing a published prescription [1], 1.55 mL of Me3SiNEt2 vere added dropwise to a solution of 0.72 g TaCls in 20 mL dithyl ether/toluene mixture (1:3). The orange solution was alowed to stir at room temperature for 24 h. Afterwards, the solvent vas removed in vacuum, which leads to a ruby red solid. This olid was dissolved in dried pentane and stored at 0 °C for 12 h,-30 °C for 24 h and-65 °C for 24 h. A broken piece of a red, neelle-shaped crystal, which was selected from the cold mother soluion, was mounted using a nylon loop for X-ray diffraction.
Zeitschrift für Kristallographie - New Crystal Structures, 2009
added, bronze needles of the partially oxidized Ki .7s[Pt(CN)4] • 1.5H 2 0 form [2], Discussion I... more added, bronze needles of the partially oxidized Ki .7s[Pt(CN)4] • 1.5H 2 0 form [2], Discussion In monoclinic Pt(CN>4 • 2H2O the Pt-C distances of 2.010 Â, in good agreement with the literature [3,4], are similar to the short Pt-O distances of 2.017 Â. Therefore the platinum is octahedrally coordinated by four cyanide ligands and two oxygen atoms of the water molecules. This arrangement is similar to the potassium tetracyanoplatinate halogenides K2[Pt(CN)4X2] (X = CI, Br, I) [S] with the water molecules replacing the halogene atoms. The Pt atoms, as the center of the octahedra, are forming a face centered arrangement, and the Pt(CN)4-2H2O octahedra are linked to each other by hydrogen bonds between the nitrogen atoms and the H2O molecules of neighbouring complexes forming a 3D network, with Ν-Η distances of 1.713 and 1.743 Â and the N-H-O distances of 2.631 and 2.602 Â.
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Papers by Jürgen Nuss