scholarly journals High-Temperature Cooperative Spin Crossover Transitions and Single-Crystal Reflection Spectra of [FeIII(qsal)2](CH3OSO3) and Related Compounds

Crystals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 81 ◽  
Author(s):  
Kazuyuki Takahashi ◽  
Kaoru Yamamoto ◽  
Takashi Yamamoto ◽  
Yasuaki Einaga ◽  
Yoshihito Shiota ◽  
...  
Keyword(s):  
High Temperature ◽  
Single Crystal ◽  
Crystal Structures ◽  
Optical Conductivity ◽  
Density Functional ◽  
Spin Crossover ◽  
Thermal Hysteresis ◽  
Reflection Spectra ◽  
Absorption Bands ◽  
Conductivity Spectra

New Fe(III) compounds from qsal ligand, [Fe(qsal)2](CH3OSO3) (1) and [Fe(qsal)2](CH3SO3)·CH3OH (3), along with known compound, [Fe(qsal)2](CF3SO3) (2), were obtained as large well-shaped crystals (Hqsal = N-(8-quinolyl)salicylaldimine). The compounds 1 and 2 were in the low-spin (LS) state at 300 K and exhibited a cooperative spin crossover (SCO) transition with a thermal hysteresis loop at higher temperatures, whereas 3 was in the high-spin (HS) state below 300 K. The optical conductivity spectra for 1 and 3 were calculated from the single-crystal reflection spectra, which were, to the best of our knowledge, the first optical conductivity spectra of SCO compounds. The absorption bands for the LS and HS [Fe(qsal)2] cations were assigned by time-dependent density functional theory calculations. The crystal structures of 1 and 2 consisted of a common one-dimensional (1D) array of the [Fe(qsal)2] cation, whereas that of 3 had an unusual 1D arrangement by π-stacking interactions which has never been reported. The crystal structures in the high-temperature phases for 1 and 2 indicate that large structural changes were triggered by the motion of counter anions. The comparison of the crystal structures of the known [Fe(qsal)2] compounds suggests the significant role of a large non-spherical counter-anion or solvate molecule for the total lattice energy gain in the crystal of a charged complex.

Dynamical control of the spin transition inside the thermal hysteresis loop of a spin-crossover single crystal

2016 ◽  
Vol 486 ◽  
pp. 187-191 ◽  
Author(s):  
Kamel Boukheddaden ◽  
Mouhamadou Sy ◽  
Miguel Paez-Espejo ◽  
Ahmed Slimani ◽  
François Varret
Keyword(s):  
Single Crystal ◽  
Hysteresis Loop ◽  
Spin Crossover ◽  
Thermal Hysteresis ◽  
Spin Transition ◽  
Thermal Hysteresis Loop ◽  
Dynamical Control

scholarly journals Substituent Effects in 3,3’ Bipyrazole Derivatives. X-ray Crystal Structures, Molecular Properties and DFT Analysis

2021 ◽  
Vol 68 (3) ◽  
pp. 718-727
Author(s):  
Ibrahim Bouabdallah ◽  
Tarik Harit ◽  
Mahmoud Rahal ◽  
Fouad Malek ◽  
Monique Tillard ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Density Functional Theory ◽  
Solid State ◽  
Dft Calculations ◽  
Single Crystal ◽  
Crystal Structures ◽  
Density Functional ◽  
Substituent Effects ◽  
Functional Theory ◽  
X Ray

The single crystal X-ray structure of new 1,1’-bis(2-nitrophenyl)-5,5’-diisopropyl-3,3’-bipyrazole, 1, is triclinic P I–, a = 7.7113(8), b = 12.3926(14), c = 12.9886(12) Å, α = 92.008(8), β = 102.251(8), γ = 99.655(9)°. The structural arrangement is compared to that of 5,5’-diisopropyl-3,3’-bipyrazole, 5, whose single crystal structure is found tetragonal I41/a, a = b = 11.684(1), c = 19.158(1) Å. The comparison is also extended to the structures previously determined for 1,1’-bis(2-nitrophenyl)-5,5’-propyl-3,3’-bipyrazole, 2, 1,1’-bis(4-nitrophenyl)-5,5’-diisopropyl-3,3’-bipyrazole, 3, and 1,1’-bis(benzyl)-5,5’-diisopropyl-3,3’-bipyrazole, 4. Density Functional Theory (DFT) calculations are used to investigate the molecular geometries and to determine the global reactivity parameters. The geometry of isolated molecules and the molecular arrangements in the solid state are analyzed according to the nature of the groups connected to the bipyrazole core.

High-pressure syntheses and crystal structures of orthorhombic DyGaO3 and trigonal GaBO3

2015 ◽  
Vol 70 (4) ◽  
pp. 207-214 ◽  
Author(s):  
Daniela Vitzthum ◽  
Stefanie A. Hering ◽  
Lukas Perfler ◽  
Hubert Huppertz
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Single Crystal ◽  
Crystal Structures ◽  
Diffraction Data ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
High Pressure High Temperature

AbstractOrthorhombic dysprosium orthogallate DyGaO3 and trigonal gallium orthoborate GaBO3 were synthesized in a Walker-type multianvil apparatus under high-pressure/high-temperature conditions of 8.5 GPa/1350 °C and 8 GPa/700 °C, respectively. Both crystal structures could be determined by single-crystal X-ray diffraction data collected at room temperature. The orthorhombic dysprosium orthogallate crystallizes in the space group Pnma (Z = 4) with the parameters a = 552.6(2), b = 754.5(2), c = 527.7(2) pm, V = 0.22002(8) nm3, R1 = 0.0309, and wR2 = 0.0662 (all data) and the trigonal compound GaBO3 in the space group R3̅c (Z = 6) with the parameters a = 457.10(6), c = 1419.2(3) pm, V = 0.25681(7) nm3, R1 = 0.0147, and wR2 = 0.0356 (all data).

Spatiotemporal Investigations on Light-Driven High-Spin–Low-Spin Interface Dynamics in the Thermal Hysteresis Region of a Spin-Crossover Single Crystal

2018 ◽  
Vol 122 (36) ◽  
pp. 20952-20962 ◽  
Author(s):  
Mouhamadou Sy ◽  
Rachid Traiche ◽  
Houcem Fourati ◽  
Yogendra Singh ◽  
François Varret ◽  
...  
Keyword(s):  
Single Crystal ◽  
High Spin ◽  
Spin Crossover ◽  
Thermal Hysteresis ◽  
Interface Dynamics

scholarly journals High-Pressure Syntheses, Crystal Structures, And Thermal Behaviour Of β-Re(Bo2)3 (Re = Nd, Sm, Gd)

2007 ◽  
Vol 62 (6) ◽  
pp. 765-770 ◽  
Author(s):  
Holger Emme ◽  
Gunter Heymann ◽  
Almut Haberer ◽  
Hubert Huppertz
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Single Crystal ◽  
Crystal Structures ◽  
Thermal Behaviour ◽  
Diffraction Data ◽  
Ambient Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Conditions

The compounds β -RE(BO2)3 [RE = Nd (neodymium meta-borate), Sm (samarium meta-borate) and Gd (gadolinium meta-borate)] were synthesized under high-pressure and high-temperature conditions in a Walker-type multianvil apparatus at 3.5 GPa (Nd), 7.5 GPa (Sm, Gd) and 1050 °C. The crystal structures were determined by single crystal X-ray diffraction data collected at r. t. (Sm, Gd) and at−73°C (Nd), respectively. The structures are isotypic with the already known ambient-pressure phases β -RE(BO2)3 (RE = (Tb, Dy) and the high-pressure phases β -RE(BO2)3 (RE = Ho-Lu)

scholarly journals Al5B12O25(OH) and Ga4InB12O25(OH) – two additional triel borates with the structure type M5B12O25(OH) (M = Ga, In)

2020 ◽  
Vol 75 (6-7) ◽  
pp. 605-613
Author(s):  
Daniela Vitzthum ◽  
Daniel S. Wimmer ◽  
Ingo Widmann ◽  
Hubert Huppertz
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Ir Spectroscopy ◽  
Single Crystal ◽  
Crystal Structures ◽  
Structure Type ◽  
Hydroxyl Groups ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Pressure High Temperature

AbstractThe isotypic triel borates Al5B12O25(OH) and Ga4InB12O25(OH) were synthesized in a Walker-type multianvil apparatus under high-pressure/high-temperature conditions of 12.0 GPa/1400 °C and 12.3 GPa/1200 °C, respectively. The crystal structures of both compounds, determined by single-crystal X-ray diffraction, constitute new representatives of the structure type M5B12O25(OH) (M = Ga, In) crystallizing in the space group I41/acd. The presence of the hydroxyl groups was confirmed via single-crystal IR spectroscopy.

Crystal structures of ammonium citrates

2018 ◽  
Vol 34 (1) ◽  
pp. 35-43 ◽  
Author(s):  
Austin M. Wheatley ◽  
James A. Kaduk
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Single Crystal ◽  
Crystal Structures ◽  
Density Functional ◽  
Hydroxyl Group ◽  
Powder Diffraction File ◽  
Functional Theory ◽  
Overlap Population ◽  
The Density Functional Theory

The crystal structures of (NH4)H2C6H5O7 and (NH4)3C6H5O7 have been determined using a combination of powder and single crystal techniques. The structure of (NH4)2HC6H5O7 has been determined previously by single crystal diffraction. All three structures were optimized using density functional techniques. The crystal structures are dominated by N-H⋅⋅⋅O hydrogen bonds, though O-H⋅⋅⋅O hydrogen bonds are also important. In (NH4)H2C6H5O7 very strong centrosymmetric charge-assisted O-H-O hydrogen bonds link one end of the citrate into chains along the b-axis. A more-normal O-H⋅⋅⋅O hydrogen bond links the other end of the citrate to the central ionized carboxyl group. In (NH4)2HC6H5O7, the very strong centrosymmetric O-H-O hydrogen bonds link the citrates into zig-zag chains along the b-axis. The citrates occupy layers parallel to the bc plane, and the ammonium ions link the layers through N-H⋅⋅⋅O hydrogen bonds. In (NH4)3C6H5O7, the hydroxyl group forms a hydrogen bond to a terminal carboxylate, and there is an extensive array of N-H⋅⋅⋅O hydrogen bonds. The energies of the density functional theory-optimized structures lead to a correlation between the energy of an N-H⋅⋅⋅O hydrogen bond and the Mulliken overlap population: E(N-H⋅⋅⋅O) (kcal/mole) = 23.1(overlap)½. Powder patterns of (NH4)H2C6H5O7 and (NH4)3C6H5O7 have been submitted to International Centre for Diffraction Data for inclusion in the powder diffraction file.

Spatiotemporal Observation and Modeling of Remarkable Temperature Scan Rate Effects on the Thermal Hysteresis in a Spin-Crossover Single Crystal

2017 ◽  
Vol 121 (21) ◽  
pp. 11700-11708 ◽  
Author(s):  
Rachid Traiche ◽  
Mouhamadou Sy ◽  
Hassane Oubouchou ◽  
Guillaume Bouchez ◽  
François Varret ◽  
...  
Keyword(s):  
Single Crystal ◽  
Spin Crossover ◽  
Thermal Hysteresis ◽  
Rate Effects ◽  
Scan Rate

Equilibrium langbeinite-related phosphates Cs1 + x Ln x Zr2 − x (PO4)3 (Ln = Sm–Lu) in the melted systems Cs2O–P2O5–LnF3–ZrF4

2007 ◽  
Vol 63 (6) ◽  
pp. 819-827 ◽  
Author(s):  
Ivan V. Ogorodnyk ◽  
Vyacheslav N. Baumer ◽  
Igor V. Zatovsky ◽  
Nikolay S. Slobodyanik ◽  
Oleg V. Shishkin ◽  
...  
Keyword(s):  
High Temperature ◽  
Single Crystal ◽  
Crystal Structures ◽  
Lanthanide Ions ◽  
Cross Linking ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Cubic System ◽  
Temperature Crystallization

Nine novel phosphates, based upon a combination of caesium, zirconium and lanthanide ions, were obtained from fluoride-containing fluxes using high-temperature crystallization. The structures of Cs1.80Eu0.80Zr1.20(PO4)3 (CsEuZrP), Cs1.79Gd0.79Zr1.21(PO4)3 (CsGdZrP), Cs1.87Tb0.87Zr1.13(PO4)3 (CsTbZrP), Cs1.67Dy0.67Zr1.33(PO4)3 (CsDyZrP), Cs1.75Ho0.75Zr1.25(PO4)3 (CsHoZrP), Cs1.78Er0.78Zr1.22(PO4)3 (CsErZrP), Cs1.70Tm0.70Zr1.30(PO4)3 (CsTmZrP), Cs1.52Yb0.52Zr1.48(PO4)3 (CsYbZrP) and Cs1.63Lu0.63Zr1.37(PO4)3 (CsLuZrP) were solved using single-crystal X-ray diffraction. All compounds are isostructural to the mineral langbeinite (cubic system, space group P213). Their framework structures originate from the cross-linking of metal octahedra [MO6] (M = Zr, Ln) by phosphate tetrahedra. Cs+ cations are located in the closed cavities of the framework and preferentially occupy one of the two available sites. The principles of crystallization of the equilibrium langbeinite-related phosphates in the fluxes of the system Cs2O–P2O5–LnF3–ZrF4 (Ln = La–Nd, Sm–Lu) are discussed based on their crystal structures.

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