Characterization on crystal structure of CH3NH3PbIxCl3−x perovskite by variable temperature powder X-ray diffraction

2019 ◽  
Vol 235 ◽  
pp. 239-241 ◽  
Author(s):  
Xue Chen ◽  
Ning Li ◽  
Yuan Li ◽  
Ping Che
Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4404
Author(s):  
Shengyang Guan ◽  
David C. Mayer ◽  
Christian Jandl ◽  
Sebastian J. Weishäupl ◽  
Angela Casini ◽  
...  

A new solvatomorph of [Au3(1-Methylimidazolate)3] (Au3(MeIm)3)—the simplest congener of imidazolate-based Au(I) cyclic trinuclear complexes (CTCs)—has been identified and structurally characterized. Single-crystal X-ray diffraction revealed a dichloromethane solvate exhibiting remarkably short intermolecular Au⋯Au distances (3.2190(7) Å). This goes along with a dimer formation in the solid state, which is not observed in a previously reported solvent-free crystal structure. Hirshfeld analysis, in combination with density functional theory (DFT) calculations, indicates that the dimerization is generally driven by attractive aurophilic interactions, which are commonly associated with the luminescence properties of CTCs. Since Au3(MeIm)3 has previously been reported to be emissive in the solid-state, we conducted a thorough photophysical study combined with phase analysis by means of powder X-ray diffraction (PXRD), to correctly attribute the photophysically active phase of the bulk material. Interestingly, all investigated powder samples accessed via different preparation methods can be assigned to the pristine solvent-free crystal structure, showing no aurophilic interactions. Finally, the observed strong thermochromism of the solid-state material was investigated by means of variable-temperature PXRD, ruling out a significant phase transition being responsible for the drastic change of the emission properties (hypsochromic shift from 710 nm to 510 nm) when lowering the temperature down to 77 K.


2000 ◽  
Vol 55 (9) ◽  
pp. 796-802 ◽  
Author(s):  
H. Kara ◽  
Y. Elerman ◽  
K. Prout

Preparation and magnetic properties of a 3,5-dimethylpyrazolate bridged binuclear copper(II) complex [Cu2(L)(3 ,5 -pyz)] (L = 1,3-Bis(2-Hydroxy-5-Chlorosalicylideneamino)propan- 2-ol) is reported. The crystal structure determined by X-ray diffraction methods. (C22H20N4O3CI2CU2), triclinic, space group P1̄, a = 9.622(3), b = 10.921(2), c = 11.420(3) Å, α = 100.73(2), β = 94.04(2), Υ = 108.08(2)°, V = 1110.2(5) Å3, Z = 2. Two copper(II) ions in a square-planar coordination are bridged via alkoxide oxygen and 3,5-dimethyl pyrozolate nitrogen atoms to form a dinuclear unit. The metal coordination sphere is four-coordinate, planar with an N2O2 donor set. The dihedral angle between the two coordination planes is 166.83°. There are significant intermolecular interactions between neighbouring binuclear entities. The shortest intermolecular Cu (1) ... Cu(1)i distance is 3.383(1) Å and the Cu(1) - O ( 1)i distance is 2.666(3) Å (i = 1 -x, -y, 1 - z). The variable-temperature magnetic susceptibility measurement for a powdered sample of the complex was carried out in the temperature range 5 - 350 K and analysed to obtain values of the parameter J in the exchange Hamiltonian ℋ = -2JScu Scu; 2J = -164 cm-1. The magnetic moment at 300 K is about 2.42 μB, and 0.22 μB at 5 K. The weak antiferromagnetism of the present complex is reasonably explained in terms of the orbital countercomplementary effect based on Hoffmann's theory for super-exchange interaction


1997 ◽  
Vol 53 (3) ◽  
pp. 394-404 ◽  
Author(s):  
E. Boldyreva ◽  
J. Kivikoski ◽  
J. A. K. Howard

The anisotropy of the structural distortion of [Co(NH3)5NO2]Cl(NO3), pentaamminenitrocobalt(III) chloride nitrate, on cooling from 290 to 150 K was studied by variable-temperature single-crystal X-ray diffraction. The changes in lattice parameters were used to calculate the strain tensors and to scan linear distortion in various crystallographic directions. The changes of different intra- and intermolecular distances in the structure were followed. Lattice strain induced by low temperature was compared with lattice strain in the same structure under high hydrostatic pressure and with lattice strain induced by homogeneous nitro–nitrito linkage isomerization.


1978 ◽  
Vol 56 (4) ◽  
pp. 450-455 ◽  
Author(s):  
Gordon W. Bushnell ◽  
Keith R. Dixon ◽  
Masood A. Khan

The crystal structure of cis-chlorobis(triethylphosphine)-1,8-naphthyridineplatinum(II) tetrafluoroborate has been determined by single crystal X-ray diffraction and refined to an R-value of 0.063. The cell dimensions are a = 1.4246, b = 1.2676, c = 1.6530 nm, β = 115.66°. The space group is P21/c with 4 molecules per unit cell, and the measured density is 1.665 g cm−3. The structure is essentially a 4-coordinate square planar platinum(II) complex containing monodentate 1,8-naphthyridine. Interatomic distances to platinum are: Pt—Cl, 236.6(4); Pt—P(1), 225.4(4); Pt—P(2), 225.2(4); Pt—N(1), 208.3(11); and Pt—N(2), 304.5(14) pm. The structure is discussed in relation to variable temperature nmr studies of solutions, which indicate fluxional behaviour of the heterocyclic ligand.


1984 ◽  
Vol 62 (4) ◽  
pp. 661-666 ◽  
Author(s):  
Willem Anker ◽  
Kathy A. Beveridge ◽  
Gordon W. Bushnell ◽  
Reginald H. Mitchell

The crystal structure of syn-9-phenyl-2,11-dithia[3,3]metacyclophane, 6, has been determined by single crystal X-ray diffraction and refined to an R value of 0.0723. The crystal structure is triclinic with a = 9.573(2), b = 12.010(4), c = 8.433(2) Å, α = 108.02(2)°, β = 95.95(2)°, γ = 102.25(3)°, and the space group is [Formula: see text] with two molecules per cell, D(meas) = 1.313 g cm−3, D(calc) = 1.306 g cm−3. The bridging S atoms differ in their conformations so that the S … S distance is 6.391 Å. The metacyclophane rings have a distance of 3.57 Å between their centres and form a dihedral angle of 20.5°. The phenyl substituent forms an angle of 78.6° with the adjacent ring and has an ortho H-atom very close to the internal H-atom of the opposite ring. The phenyl substituted aromatic ring is non-planar and in a shallow boat form, the ring atoms C(11) (internal) and C(14) being 0.038(4) and 0.037(5) Å out-of-plane on the outside, the methylene C substituents are 0.212(5) and 0.199(5) Å out-of-plane on the inside. The first atom of the phenyl group is in the bowsprit position and is 0.274(4) Å above the mean plane on the outer side of the molecule. The opposite metacyclophane ring is less strained but in a similar boat form with the methylene C-atoms 0.092(4) and 0.067(6) Å to the inside. The mean bond angle at S is 103.5(2)°, the angles at C (methylene) range from 113.3(3)° to 118.0(3)°.The variable temperature 1Hmr spectra results are consistent with the syn conformer 6 being dominant in solution and frozen at temperatures <60 °C as conformer A, with only relatively restricted further twisting of the biphenyl being found at ambient temperature.


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