20762-60-1Relevant academic research and scientific papers
Azidoaurates of the alkali metals
Afyon, Semih,Hoehn, Peter,Armbruester, Marc,Baranov, Alexey,Wagner, Frank R.,Somer, Mehmet,Kniep, Ruediger
, p. 1671 - 1680 (2006)
Synthesis, crystal structure as well as IR- and Raman-spectroscopic properties of the new ternary azidoaurates(III) A[Au(N3)4] (A = K, Rb, Cs) are reported. The translucent orange-red compounds were prepared by reaction of the respective binary azides with HAuCl4 in aqueous solutions at room temperature. The crystal structures determined by single crystal X-ray diffraction methods are monoclinic (C2/c (No. 15), K/Rb/Cs[Au(N3)4]: a = 1049.30(9) pm / 1033.93(10) pm / 1011.9(8) pm, b = 1047.52(8) pm / 1064.20(11) pm / 1093.8(8) pm, c = 776.97(7) pm / 809.79(8) pm / 858.4(6) pm, β = 91.220(5)° / 90.322(5)° / 92.72(5)°) and provide the first examples for azidoaurates with mono-atomic cations. The unusual reduction of the lattice parameter a with increasing cation size in the isotypic series is discussed in detail. IR-and Raman-spectroscopic measurements show strongly covalent gold-nitrogen contacts, a bonding situation which is further supported by quantum chemical calculations and ELF-analyses.
The chain manganates K29Mn17O34, Rb 11Mn8O16, and Cs4Mn 3O6: a new family of mixed-valent one-dimensional transition metallates
Pfeiffer, Steffen,Nuss, Juergen,Jansen, Martin
, p. 23 - 29 (2010)
Air and moisture sensitive K29Mn17O34, Rb11Mn8O16 and Cs4Mn 3O6 were prepared via the azide/nitrate route from stoichiometric mixtures of the precursors Mn2O3, AN 3 and ANO3 (A = K, Rb, Cs) in special containers provided with silver inlays. Their compositions can be generalized as A xMnO2 with x varying between 1.703 and 1.333. According to the X-ray analysis of the crystal structures [K29Mn 17O34: lma2, Z = 4, a = 93.149(3), b = 10.0063(3), c = 6.0621(2) A, 6585 independent reflections, R1 = 0.053, wR(all) = 0.143; Rb11Mn8O16: F222, Z = 16, a = 12.2096(4), b = 20.1595(7), c = 43.712(2) A, 11534 independent reflections, R1 = 0.042, wR(all) = 0.131; Cs4Mn3O6: C222, Z = 8, a = 12.790(3), b = 21.123(4), c =8.179(2) A, 2212 independent reflections, R1 = 0.051, wR(fall) = 0.122], the main feature of all three crystal structures are 1∞MnO2n- chains built up from partially distorted edge-sharing MnO4 tetrahedra. The alkali metal ions fill the space between the anionic entities forming honeycomb like arrangements. In all cases manganese is in a mixedvalent state but no full charge ordering is noticeable. The variations of the charges along the MnO 2n- chains seem to be best described in terms of charge density waves. The magnetic susceptibilities show the dominance of strong antiferromagnetic interactions for the rubidium and the cesium compounds, whereas ferro- or ferrimagnetic interactions prevail in the potassium compound.
Synthesis, Crystal Structure, and Magnetic Properties of K6Mn4O7 Featuring a Novel Two-Dimensional Poly-oxomanganate(II) Anion
Nuss, Jürgen,Kremer, Reinhard K.,Jansen, Martin
, p. 1715 - 1720 (2018)
K6Mn4O7 was synthesized via the azide/nitrate route from a stoichiometric mixture of the precursors KN3, KNO3, and MnO, and alternatively from the binary constituents K2O and MnO, in an all-solid state reaction. Its crystal structure [P1, Z = 1, a = 603.46(3), b = 647.69(4), c = 891.36(5) pm, α = 90.477(2)°, β = 108.417(2)°, γ = 115.358(2)°] consists of cluster-like Mn4O10 units, each composed of four edge sharing MnO4 tetrahedra. The Mn4O10 building blocks, on their part, are linked by six vertices, forming a 2D arrangement, 2∞[Mn4O4/1O6/2]n6–, with the potassium cations occupying the space in between. The temperature dependence of the magnetic susceptibility is dominated by antiferromagnetic coupling along a low-dimensional magnetic exchange path. The heat capacity reveals no clear sign of long-range magnetic ordering, supporting an interpretation of K6Mn4O7 as a new low-dimensional magnetic system.
K5Mn3O6and Rb8Mn5O10, new charge ordered quasi one-dimensional oxomanganates (II, III)
Nuss, Jürgen,Dasari, Prasad L. V. K.,Jansen, Martin
, p. 316 - 321 (2015)
K5Mn3O6 and Rb8Mn5O10 have been synthesized via the azide/nitrate route from stoichiometric mixtures of MnO and KNO3/ KN3, or RbNO3/RbN3, respectively. The two new members of manganese (II/III) mixed-valent oxides have been studied by single-crystal X-ray diffraction, magnetic susceptibility measurements and density functional theory calculations (DFT). Both crystal structures [K5Mn3O6: Pna21, Z = 4, a = 1632.43(7), b = 970.07(4), c = 616.48(3) pm, R1 = 0.051; Rb8Mn5O10: P21/c, Z = 8, a = 1223(2), b = 2717(3), c = 1220(2) pm, β = 118.25(2)° , R1 = 0.086] display quasi one-dimensional [MnO2]n-- chains, composed of edge sharing MnO4 tetrahedra. Complete charge ordering of Mn2+ and Mn3+ is observed along the chain direction with repetition units [-Mn3+-Mn2+-Mn,2+-] resulting for K5Mn3O6, and [-Mn3+-Mn2+-Mn2+-Mn3+-Mn2+-] for Rb8Mn5O10. Magnetic susceptibility data as well as DFT calculations indicate strong anti-ferromagnetic intra-chain coupling to be present already at ambient temperature, and above. Rb8Mn5O10 features threedimensional spin ordering below TN = 10.9 K, mediated by ferromagnetic coupling between the chains, while such a 3D coupling appears to be frustrated in K5Mn3O6.
Synthesis, crystal structure, and physical properties of the new chain alkalioxocuprate K3Cu2O4
Duris, Katarina,Kremer, Reinhard K.,Jansen, Martin
, p. 1101 - 1107 (2011)
Single crystals of K3Cu2O4 were prepared by the azide/nitrate route from respective stoichiometric mixtures of KN 3, KNO3 and CuO, at 923 K, whereas powder samples were synthesised by solid state reaction of K2O, KCuO2 and CuO, sealed in gold ampoules and treated at 723 K. According to the single crystal structure analysis (Cmcm, Z = 4, a = 6.1234(1), b = 8.9826(2), c = 10.8620(2) A, R1 = 0.044, R2 = 0.107), the main structural feature are undulating A1∞ CuO2 chains built up from planar, edge sharing CuO4 square units. From an analysis of the Cu-O bond lengths, the valence state of either +2 or +3 can be unambiguously assigned to each copper atom. The magnetic susceptibilities show the dominance of antiferromagnetic (AFM) interactions. At high temperatures, the magnetic behaviour can be fitted with the Curie-Weiss law (μeff = 1.84μB, θ = -105 K). The experimental data can be very well described by a uniform Heisenberg chain with a nearest-neighbour spin intrachain interaction (Jnn) of ～ 101 K. Copyright
The structure and energetics of arsenic(iii) oxide intercalated by ionic azides
Gunka, Piotr A.,Kraszewski, Karol,Chen, Yu-Sheng,Zachara, Janusz
, p. 12776 - 12783 (2014)
Unprecedented intercalates of arsenic(iii) oxide with potassium azide and ammonium azide have been obtained and characterized by single crystal X-ray diffraction. The compounds are built of As2O3 sheets separated by charged layers of cations and azide anions perpendicular to the sheets. The intercalates are an interesting example of hybrid materials whose structure is governed by covalent bonds in two directions and ionic bond in the third one. The obtained compounds are the first examples of As2O 3 intercalates containing linear pseudohalogen anions. Periodic DFT calculations of interlayer interaction energies were carried out with the B3LYP-D* functional. The layers are held together mainly by ionic bonds, although the computations indicate that interactions between cations and As 2O3 sheets also play a significant role. A comparison of cation and anion interaction energies with neutral As2O3 sheets sheds light on the crystallisation process, indicating the templating effect of potassium and ammonium cations. It consist in the formation of sandwich complexes of cations with crown-ether-resembling As6O 12 rings. Raman spectra of both compounds are recorded and computed ab initio and all vibrational bands are assigned. This journal is the Partner Organisations 2014.
The AFeO2 (A=K, Rb and Cs) family: A comparative study of structures and structural phase transitions
Ali, Naveed Zafar,Nuss, Juergen,Sheptyakov, Denis,Jansen, Martin
, p. 752 - 759 (2010)
Structures and phase transitions for the isostructural series of compounds KFeO2, RbFeO2 and CsFeO2 have been systematically studied by synchrotron X-ray high resolution powder diffraction experiments and in case of CsFeO2 also by single crystal diffractometry. At room temperature, all of the three compounds crystallize in the orthorhombic (Pbca) KGaO2 type of structure consisting of a three dimensional network of corner-sharing [FeO4/2]- tetrahedra, which at elevated temperatures shows a reversible phase transformation to a cubic structure (space group Fd over(3, -) m). For KFeO2, RbFeO2 and CsFeO2 this phase transformation takes place at 1003 K, 737 K and 350 K respectively, as confirmed by differential scanning calorimetry and X-ray diffraction. Upon heating through the transitions the major structural changes are driven by the onset or enhancement of librational motion of the FeO4 tetrahedra. Due to this phenomenon the Fe-O-Fe bonds appear to step-wise getting straight, seemingly approaching 180° within the time and space averaged structure.
Trimethylsilyl-Induced N-O Bond Cleavage in Nitrous Oxide-Derived Aminodiazotates
Liu, Yizhu,Eymann, Léonard Y. M.,Solari, Euro,Fadaei Tirani, Farzaneh,Scopelliti, Rosario,Severin, Kay
supporting information, p. 11859 - 11863 (2018/09/25)
The chemical activation of nitrous oxide (N2O) typically results in O-atom transfer and the extrusion of N2 gas. In contrast, reactions of N-trimethylsilyl (TMS)-substituted amides with N2O give inorganic or organic azides
Azides and Cyanamides - Similar and Yet Different
Reckeweg, Olaf,Simon, Arndt
, p. 1097 - 1104 (2007/10/03)
The crystal structures of LiN3*;H2O (P6 3/mcm (No. 193), Z = 6; 924.01(13); 560.06(7) pm); NH 4N3 (Pmna (No. 53), Z = 4; a = 889.78(18), b = 380,67(8), c = 867.35(17) pm); Ca(N3)2 (Fddd (No. 70), Z = 8; a = 595.4(2), b = 1103.6(5), c = 1133.1(6) pm), Sr(N3)2 (Fddd(No. 70), Z = 8; a = 612.02(9), 6 = 1154.60(18), c = 1182.62(15) pm); Ba(N3)2 (P21/m (No. 11), Z = 2; a = 544.8(1), b = 439.9(1), c = 961.3(2) pm, β = 99.64(3)°) and TIN3 (I4/mcm (No. 140), Z = 2; 618.96(9); 732.71(15) pm) have been either determined for the first time or redetermined by X-ray diffraction on single crystals. The afore mentioned compounds, AN3 (A = Na, K, Rb, Cs), M(N 3)2 · 2.5 H2O (M = Mg, Zn) and the cyanamides Li2CN2, CdCN2 and CuCN2 were investigated by Raman and IR spectroscopy (KBr technique). Structural features and spectroscopic data of azides and cyanamides from this work and from literature are listed and compared.
K4Au8Ga: a Filling Variant of the MgCu2 Type
Mueller, Juergen,Zachwieja, Uwe
, (2008/10/08)
Black, brittle single crystals of K4Au8Ga were obtained as the main product of the reaction of potassium azide with gold sponge and gallium at T=770 K. The structure of the compound (space group C2/m, Z=4, a=20.850(4) ?, b=5.630(1) ?, c=10.912(2) ?, β=97.45(2)°) was determined from X-ray single crystal diffractometry data. K4Au8Ga crystallizes in a filling variant of the MgCu2 type. The gold atoms form a (3).infin.[Au4/2]-framework. One quarter of the tetrahedra is filled by gallium. The potassium atoms are placed in channel-like cavities of the Au-Ga partial structure.
