19465-88-4Relevant articles and documents
HIP to be Square: Simplifying Nitridophosphate Synthesis in a Hot Isostatic Press
Mardazad, Sara,Schmidt, Peter J.,Schnick, Wolfgang,Strobel, Philipp,Wendl, Sebastian
, p. 18240 - 18243 (2020)
(Oxo)Nitridophosphates have recently been identified as a promising compound class for application in the field of solid-state lighting. Especially, the latest medium-pressure syntheses under ammonothermal conditions draw attention of the semiconductor and lighting industry on nitridophosphates. In this contribution, we introduce hot isostatic presses as a new type of medium-pressure synthetic tool, further simplifying nitridophosphate synthesis. In a second step, phosphorus nitride was replaced as starting material by red phosphorus, enabling the synthesis of Ca2PN3 as model compound, starting only from readily available compounds. Moreover, first luminescence investigations on Eu2+-doped samples reveal Ca2PN3:Eu2+ as a promising broad-band red-emitter (λem=650 nm; fwhm=1972 cm?1). Besides simple handling, the presented synthetic method offers access to large sample volumes, and the underlying reaction conditions facilitate single-crystal growth, required for excellent optical properties.
High-pressure synthesis and characterization of Li2Ca 3[N2]3 - An uncommon metallic diazenide with [N2]2- ions
Schneider, Sebastian B.,Seibald, Markus,Deringer, Volker L.,Stoffel, Ralf P.,Frankovsky, Rainer,Friederichs, Gina M.,Laqua, Henryk,Duppel, Viola,Jeschke, Gunnar,Dronskowski, Richard,Schnick, Wolfgang
, p. 16668 - 16679 (2013)
Dinitrogen (N2) ligation is a common and well-characterized structural motif in bioinorganic synthesis. In solid-state chemistry, on the other hand, homonuclear dinitrogen entities as structural building units proved existence only very recently. High-pressure/high-temperature (HP/HT) syntheses have afforded a number of binary diazenides and pernitrides with [N 2]2- and [N2]4- ions, respectively. Here, we report on the HP/HT synthesis of the first ternary diazenide. Li 2Ca3[N2]3 (space group Pmma, no. 51, a = 4.7747(1), b = 13.9792(4), c = 8.0718(4) A, Z = 4, wRp = 0.08109) was synthesized by controlled thermal decomposition of a stoichiometric mixture of lithium azide and calcium azide in a multianvil device under a pressure of 9 GPa at 1023 K. Powder X-ray diffraction analysis reveals strongly elongated N-N bond lengths of dNN = 1.34(2)-1.35(3) A exceeding those of previously known, binary diazenides. In fact, the refined N-N distances in Li2Ca3[N2]3 would rather suggest the presence of [N2]3·- radical ions. Also, characteristic features of the N-N stretching vibration occur at lower wavenumbers (1260-1020 cm-1) than in the binary phases, and these assignments are supported by first-principles phonon calculations. Ultimately, the true character of the N2 entity in Li 2Ca3[N2]3 is probed by a variety of complementary techniques, including electron diffraction, electron spin resonance spectroscopy (ESR), magnetic and electric conductivity measurements, as well as density-functional theory calculations (DFT). Unequivocally, the title compound is shown to be metallic containing diazenide [N2] 2- units according to the formula (Li+) 2(Ca2+)3([N2]2-) 3·(e-)2.
Nitridophosphate-Based Ultra-Narrow-Band Blue-Emitters: Luminescence Properties of AEP8N14:Eu2+ (AE=Ca, Sr, Ba)
Wendl, Sebastian,Eisenburger, Lucien,Strobel, Philipp,Günther, Daniel,Wright, Jonathan P.,Schmidt, Peter J.,Oeckler, Oliver,Schnick, Wolfgang
, p. 7292 - 7298 (2020/05/18)
The nitridophosphates AEP8N14 (AE=Ca, Sr, Ba) were synthesized at 4–5 GPa and 1050–1150 °C applying a 1000 t press with multianvil apparatus, following the azide route. The crystal structures of CaP8N14 and SrP8N14 are isotypic. The space group Cmcm was confirmed by powder X-ray diffraction. The structure of BaP8N14 (space group Amm2) was elucidated by a combination of transmission electron microscopy and diffraction of microfocused synchrotron radiation. Phase purity was confirmed by Rietveld refinement. IR spectra are consistent with the structure models and the chemical compositions were confirmed by X-ray spectroscopy. Luminescence properties of Eu2+-doped samples were investigated upon excitation with UV to blue light. CaP8N14 (λem=470 nm; fwhm=1380 cm?1) and SrP8N14 (λem=440 nm; fwhm=1350 cm?1) can be classified as the first ultra-narrow-band blue-emitting Eu2+-doped nitridophosphates. BaP8N14 shows a notably broader blue emission (λem=417/457 nm; fwhm=2075/3550 cm?1).
Synthesis of alkaline earth diazenides MAEN2 (M AE = Ca, Sr, Ba)by Controlled Thermal Decomposition of Azides under High Pressure
Schneider, Sebastian B.,Frankovsky, Rainer,Schnick, Wolfgang
, p. 2366 - 2373 (2012/04/18)
The alkaline earth diazenides MAEN2 with M AE = Ca, Sr andBa were synthesized by a novel synthetic approach, namely, a controlleddecomposition of the corresponding azides in a multianvil press at highpressure/high-temperature conditions. The crystal structure of hithertounknown calcium diazenide (space group I4/mmm (no. 139), a = 3.5747(6)A, c = 5.9844(9)A, Z = 2, wRp = 0.078)was solved and refined on the basisof powder X-ray diffraction data as well as that of SrN 2 and BaN2.Accordingly, CaN2 is isotypic with SrN2 (space group I4/mmm (no. 139), a =3.8054(2)A, c = 6.8961(4)A, Z = 2, wRp = 0.057)and the correspondingalkaline earth acetylenides (MAEC2)crystallizing in a tetragonally distortedNaCl structure type. In accordance with literature data, BaN2 adopts a moredistorted structure in space group C2/c (no. 15)with a = 7.1608(4)A, b =4.3776(3)A, c = 7.2188(4)A, β = 104.9679(33)°, Z = 4 and wRp = 0.049).The N-N bond lengths of 1.202(4)A in CaN2 (SrN2 1.239(4)A, BaN21.23(2)A)correspond well with a double-bonded dinitrogen unit confirming a diazenide ion [N 2]2-. Temperature-dependent insitu powder X-ray diffractometry of the three alkaline earth diazenides resulted in formation of the corresponding subnitridesMAE2N (MAE = Ca, Sr, Ba)at higher temperatures. FTIR spectroscopy revealed a band at about 1380 cm-1 assigned to the N-Nstretching vibration of the diazenide unit. Electronic structure calculations support the metallic character of alkaline earthdiazenides.
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.
