Na2La4(NH2)14·NH3, a lanthanum-rich intermediate in the ammonothermal synthesis of LaN and the effect of ammonia loss on the crystal structure

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sebastian Kunkel ◽  
Rainer Niewa
Keyword(s):  
Crystal Structure ◽  
Liquid Ammonia ◽  
Spectroscopic Studies ◽  
Ammonia Loss ◽  
Raman Spectroscopic ◽  
Sodium Cations ◽  
Retrograde Solubility ◽  
Third Dimension ◽  
Supercritical Ammonia ◽  
Similar Unit

Abstract Single crystals of Na2La4(NH2)14·NH3 were obtained from supercritical ammonia under ammonobasic conditions at a temperature of 573 K and 120 MPa pressure. It represents a lanthanum-rich intermediate in the ammonothermal synthesis of LaN. Upon aging, the title compound loses the crystal ammonia, resulting in pale crystals of Na2La4(NH2)14, the original space group P212121 being retained in a very similar unit cell. However, the crystal structure reacts to subtle changes in the composition as well as to the modified coordination of particularly the sodium cations interconnecting lanthanum amide layers within a third dimension. Results of Raman spectroscopic studies are reported. The observations of thermal analysis measurements indicating the formation of lanthanum nitride, in combination with the observed retrograde solubility in liquid ammonia, contribute to the knowledge of the ammonothermal crystal growth of lanthanum nitride.

Synthesis of Zn1–xMgxO and its structural characterization

2001 ◽  
Vol 16 (4) ◽  
pp. 903-906 ◽  
Author(s):  
M. S. Tomar ◽  
R. Melgarejo ◽  
P. S. Dobal ◽  
R. S. Katiyar
Keyword(s):  
Crystal Structure ◽  
Spin Coating ◽  
Optoelectronic Devices ◽  
Spectroscopic Studies ◽  
Structural Behavior ◽  
Material System ◽  
X Ray Diffraction ◽  
X Ray ◽  
Raman Spectroscopic ◽  
Mg Substitution

Zn1–xMgxO is an important material for optoelectronic devices. We synthesized this material using a solution-based route. We investigated in detail the structural behavior of this material system using x-ray diffraction and Raman spectroscopy. Mg substitution up to x ≈ 0.10 does not change the crystal structure, as revealed by x-ray diffraction and Raman spectroscopic studies. This synthesis route is also suitable to prepare thin films by spin coating with the possibility of p and n doping.

Raman Spectroscopic Studies of Amsacrine

1992 ◽  
Vol 46 (10) ◽  
pp. 1540-1544 ◽  
Author(s):  
Catherine A. Butler ◽  
Ralph P. Cooney ◽  
William A. Denny
Keyword(s):  
Crystal Structure ◽  
Raman Spectroscopy ◽  
Crystal Structure Data ◽  
Visible Spectrum ◽  
Spectroscopic Studies ◽  
Resonance Raman Spectrum ◽  
Raman Spectroscopic ◽  
Ft Raman Spectroscopy ◽  
Uv Visible ◽  
Ft Raman

Amsacrine (4′-(9-acridinylamino)methanesulfon- m-anisidide) in both solid and aqueous forms was characterized with the use of resonance and nonresonance Raman spectroscopy (including FT-Raman spectroscopy). Evidence that the acridine nucleus is the dominant chromophoric unit contributing to the resonance Raman spectrum is based upon the apparent similarities of the spectra of aqueous amsacrine (in the unpro-tonated form) and acridine (in ethanol). The probable non-coplanarity of the acridine and phenyl units in the amsacrine molecule (based on previously reported crystal structure data) is consistent with the suggestion that the acridine nucleus may constitute an independent chromophoric unit. Further evidence is derived from analysis of the UV-visible spectrum, which indicates that excitation at 457.9 nm falls within an electronic transition of the acridine nucleus of amsacrine. The excitation profiles of aqueous amsacrine are presented, and four types of profiles have been identified.

Molybdophyllite: crystal chemistry, crystal structure, OD character and modular relationships with britvinite

2012 ◽  
Vol 76 (3) ◽  
pp. 493-516 ◽  
Author(s):  
U. Kolitsch ◽  
S. Merlino ◽  
D. Holtstam
Keyword(s):  
Crystal Structure ◽  
Layered Silicate ◽  
Chemical Study ◽  
Spectroscopic Studies ◽  
Sensu Stricto ◽  
Crystal Chemical ◽  
X Ray Diffraction ◽  
Space Group ◽  
Raman Spectroscopic ◽  
Ir And Raman

AbstractA detailed crystal-chemical study of the complex layered silicate molybdophyllite was conducted using single-crystal X-ray diffraction (XRD) methods, supplemented by powder XRD, infrared (IR) and Raman spectroscopic studies, chemical analyses by energy-dispersive spectrometry (EDS) on a scanning electron microscope (SEM), and electron probe microanalysis (EPMA). The results, based on several samples from both Långban and Harstigen, Filipstad, Sweden, show that the crystal structure of molybdophyllite has an order-disorder (OD) character. The latter is especially evident in specimens from Långban which display a complex diffraction pattern characterized by the simultaneous presence of sharp spots, diffuse reflections and continuous streaks. The sharp reflections define the unit cell of the family structure (a = 3.124, c = 41.832 Å, space group R32). Two main polytypes (maximum degree of order structures) are indicated by the OD approach: a trigonal one and a monoclinic one; the latter polytype is the most common in the samples that were studied and has space group C2, with a = 16.232(6), b = 9.373(2), c = 14.060(3) Å, b = 97.36(4)º and V = 2121.5(10) Å3.The crystal structure determination [R1= 0.096], together with the EPMA, IR and Raman data, reveal that molybdophyllite is built up by a regular alternation of complex layers with a composition {Mg9[Si10O28(OH)8][OPb4]2}6+and simple layers with a composition [(CO3)3·H2O]6–, leading to the ideal crystal-chemical formula Pb8Mg9[Si10O28(OH)8|O2|(CO3)3]·H2O (Z = 2).This contribution is mainly devoted to the results obtained for molybdophyllite sensu stricto, but new data for britvinite [i.e. 'molybdophyllite-18 Å'] are also presented and its modular relationship with molybdophyllite is discussed.

Synthesis, Crystal Structure And Spectroscopic Studies Of A Mixed Ligand Copper (Ii) Complex: Trans-Bis(Succinimidato)-Bis(Benzylamino)Cu(Ii)

2006 ◽  
Vol 61 (8) ◽  
pp. 979-982 ◽  
Author(s):  
Murat Taş ◽  
Hanife Saraçoğlu ◽  
Hümeyra Bati ◽  
Nezihe Çalışkan ◽  
Orhan Büyükgüngör
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Spectroscopic Studies ◽  
Mixed Ligand ◽  
Interplanar Angle ◽  
Space Group ◽  
Square Planar

The molecules of the title compound, [Cu(C11H13N2O2)2], lie across centres of inversion in space group P21/c and are linked by intermolecular N-H···O and C-H···O hydrogen bonds. The central Cu atom has a slightly distorted square-planar coordination comprised of four N atoms. Cu-N bond distances are 1.975(2) and 2.020(2) Å . The interplanar angle between the phenyl and succinimidato ring is 87.34(10)°

Crystal structure and temperature-dependent properties of Na2H4Ga2GeO8 – a novel gallogermanate

2020 ◽  
Vol 75 (9-10) ◽  
pp. 805-813
Author(s):  
Irma Peschke ◽  
Lars Robben ◽  
Christof Köhler ◽  
Thomas Frauenheim ◽  
Josef-Christian Buhl ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Decomposition Temperature ◽  
Spectroscopic Techniques ◽  
Charge Balance ◽  
Temperature Dependent ◽  
Raman Spectroscopic ◽  
Debye Temperatures ◽  
Diffraction Lattice ◽  
Temperature Dependent Properties ◽  
Balance Structure

AbstractSynthesis, crystal structure and temperature-dependent behavior of Na2H4Ga2GeO8 are reported. This novel gallogermanate crystallizes in space group I41/acd with room-temperature powder diffraction lattice parameters of a = 1298.05(1) pm and c = 870.66(1) pm. The structure consists of MO4 (M = Ga, Ge) tetrahedra in four-ring chains, which are connected by two different (left- and right-handed) helical chains of NaO6 octahedra. Protons coordinating the oxygen atoms of the GaO4 tetrahedra not linked to germanium atoms ensure the charge balance. Structure solution and refinement are based on single crystal X-ray diffraction measurements. Proton positions are estimated using a combined approach of DFT calculations and NMR, FTIR and Raman spectroscopic techniques. The thermal expansion was examined in the range between T = 20(2) K and the compound’s decomposition temperature at 568(5) K, in which no phase transition could be observed, and Debye temperatures of 266(11) and 1566(65) K were determined for the volume expansion.

Spectroscopic Studies and Crystal Structure of 4-(2-Hydroxy-3-Methoxybenzylideneamino)-N-(5-Methylisoxazol-3-yl) Benzenesulfonamide

2010 ◽  
Vol 40 (8) ◽  
pp. 691-695 ◽  
Author(s):  
Mustafa Yıldız ◽  
Hüseyin Ünver ◽  
Diğdem Erdener ◽  
Nazan Ocak İskeleli
Keyword(s):  
Crystal Structure ◽  
Spectroscopic Studies
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