A new polymorph of terpyridine: variable temperature X-ray diffraction studies and solid state photophysical properties

CrystEngComm ◽  
2005 ◽  
Vol 7 (43) ◽  
pp. 269 ◽  
Author(s):  
Katharine F. Bowes ◽  
Ian P. Clark ◽  
Jacqueline M. Cole ◽  
Matthew Gourlay ◽  
Alexandra M. E. Griffin ◽  
...  
Keyword(s):  
Solid State ◽  
Variable Temperature ◽  
Photophysical Properties ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Investigation of Solvatomorphism and Its Photophysical Implications for Archetypal Trinuclear Au3(1-Methylimidazolate)3

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4404
Author(s):  
Shengyang Guan ◽  
David C. Mayer ◽  
Christian Jandl ◽  
Sebastian J. Weishäupl ◽  
Angela Casini ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Density Functional ◽  
Bulk Material ◽  
Variable Temperature ◽  
Active Phase ◽  
Solvent Free ◽  
X Ray Diffraction ◽  
X Ray ◽  
Aurophilic Interactions

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.

scholarly journals A combined single crystal neutron/X-ray diffraction and solid-state nuclear magnetic resonance study of the hybrid perovskites CH3NH3PbX3 (X = I, Br and Cl)

2015 ◽  
Vol 3 (17) ◽  
pp. 9298-9307 ◽  
Author(s):  
Tom Baikie ◽  
Nathan S. Barrow ◽  
Yanan Fang ◽  
Philip J. Keenan ◽  
Peter R. Slater ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Solid State ◽  
Single Crystal ◽  
Solid State Nmr ◽  
Variable Temperature ◽  
Neutron Diffraction Study ◽  
Nuclear Magnetic Resonance Study ◽  
X Ray Diffraction ◽  
Magnetic Resonance Study ◽  
X Ray

This article describes a variable temperature solid-state NMR and single crystal X-ray/neutron diffraction study of the hybrid perovskites (CH3NH3)PbX3 (X = I, Br and Cl).

Tautomeric polymorphism of the neuroactive inhibitor kynurenic acid

2019 ◽  
Vol 75 (6) ◽  
pp. 793-805
Author(s):  
Dorota Pogoda ◽  
Jan Janczak ◽  
Sylwia Pawlak ◽  
Michael Zaworotko ◽  
Veneta Videnova-Adrabinska
Keyword(s):  
Solid State ◽  
Kynurenic Acid ◽  
Variable Temperature ◽  
Neurological Diseases ◽  
Crystal Form ◽  
Phase Behaviour ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray

Kynurenic acid (KYN; systematic name: 4-hydroxyquinoline-2-carboxylic acid, C10H7NO3) displays a therapeutic effect in the treatment of some neurological diseases and is used as a broad-spectrum neuroprotective agent. However, it is understudied with respect to its solid-state chemistry and only one crystal form (α-KYN·H2O) has been reported up to now. Therefore, an attempt to synthesize alternative solid-state forms of KYN was undertaken and six new species were obtained: five solvates and one salt. One of them is a new polymorph, β-KYN·H2O, of the already known KYN monohydrate. All crystal species were further studied by single-crystal and powder X-ray diffraction, thermal and spectroscopic methods. In addition to the above methods, differential scanning calorimetry (DSC), in-situ variable-temperature powder X-ray diffraction and Raman microscopy were applied to characterize the phase behaviour of the new forms. All the compounds display a zwitterionic form of KYN and two different enol–keto tautomers are observed depending on the crystallization solvent used.

Structural characterization of p-benzosemiquinone radical in a solid state: the radical stabilization by a low-barrier hydrogen bond

2006 ◽  
Vol 62 (6) ◽  
pp. 1051-1060 ◽  
Author(s):  
Krešimir Molčanov ◽  
Biserka Kojić-Prodić ◽  
Mario Roboz
Keyword(s):  
Hydrogen Bond ◽  
Solid State ◽  
Variable Temperature ◽  
Organic Radical ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal Packings ◽  
Dynamical Disorder ◽  
Benzenoid Ring

Semiquinone (p-benzosemiquinone), a transient organic radical, was detected in the solid state by EPR spectroscopy revealing four symmetrically equivalent protons. A variable-temperature X-ray diffraction analysis (293 and 90 K) and EPR data support a dynamical disorder of the proton. A low-barrier O—H···O hydrogen bond stabilizes the radical. The C—O bond length is 1.297 (4) Å, corresponding to a bond order of ca 1.5. The geometry of the radical implies an electron delocalization throughout the benzenoid ring. Two polymorphs of semiquinone, monoclinic and triclinic, were observed and their structures determined. Their crystal packings were compared with those of quinhydrone polymorphs.

Investigation of Lattice Contraction in Mn3XN(X=Zn, Cu, Sn)

2010 ◽  
Vol 638-642 ◽  
pp. 2195-2200 ◽  
Author(s):  
Cong Wang ◽  
Ying Sun ◽  
Yong Chun Wen ◽  
Li Hua Chu ◽  
Man Nie
Keyword(s):  
Thermal Expansion ◽  
Solid State ◽  
Variable Temperature ◽  
Magnetic Transition ◽  
Transition Process ◽  
X Ray Diffraction ◽  
Lattice Contraction ◽  
X Ray ◽  
Doping Effects ◽  
Valence Electrons

The Mn3XN(X=Zn, Cu, Sn) compounds and their solid solutions with anti-perovskite structure were prepared by solid state reaction. Their magnetic transition and simultaneous abnormal thermal expansion behaviors were studied by SQUID and variable temperature X-ray diffraction. The lattice contraction was found in Mn3Cu0.5Sn0.5N and Mn3Zn0.5Sn0.5N during the magnetic transition process, however not in pure Mn3XN(X=Zn, Cu, Sn). The mechanism is discussed, combined with the different doping effects. It seems that the lattice contraction behavior is sensitive to the number of valence electrons at the X site in Mn3XN series.

scholarly journals Solid-state motion of OTeF5− compounds: detection by 19F NMR and IR spectroscopy and correlation with the X-ray structure of an orthorhombic crystalline modification of [C14H19N2+][OTeF5−] (C14H19N2+ = protonated 1,8-bis(dimethylamino)naphthalene)

1989 ◽  
Vol 67 (11) ◽  
pp. 2023-2029 ◽  
Author(s):  
Patti J. Kellett ◽  
Oren P. Anderson ◽  
Steven H. Strauss ◽  
Kent D. Abney
Keyword(s):  
Solid State ◽  
Nmr Spectra ◽  
Room Temperature ◽  
Variable Temperature ◽  
Structural Parameters ◽  
Crystalline Modification ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Triclinic Modification

An orthorhombic crystalline modification of [(PS)H+][OTeF5−] was studied by single crystal X-ray diffraction ((PS)H+ = protonated 1,8-bis(dimethylamino)naphthalene): orthorhombic, space group Cmcm, a = 8.607(2), b = 14.048(3), c = 13.365(2) Å, Z = 4, T = −130 °C. The structural parameters for the anion and cation in this modification (Mod-B) are very similar to those for the previously reported triclinic modification of this salt (Mod-A). However, variable temperature IR spectra for Mod-B suggest that the OTeF5− anion is exhibiting a two-site O/Fax interchange above −70 °C. Solid-state 19F NMR spectra suggest that this interchange may be as rapid as 104–105 s−1 at room temperature. Keywords: crystal structure of protonated 1,8-bis(dimethylamino)naphthalene)pentafluorotellurate(VI), polymorphism, solid state 19FNMR.

Synthesis, structure, photoluminescent, optical and magnetic properties of a novel thulium p-hydroxybenzenesulfonate complex

2019 ◽  
Vol 234 (3) ◽  
pp. 177-182
Author(s):  
Rong-Hua Hu ◽  
Wen-Tong Chen ◽  
Jian-gen Huang
Keyword(s):  
Magnetic Susceptibility ◽  
Solid State ◽  
Diffuse Reflectance ◽  
Magnetic Measurements ◽  
Variable Temperature ◽  
X Ray Diffraction ◽  
Monoclinic System ◽  
X Ray ◽  
Elemental Analyses ◽  
Anti Stokes

Abstract A novel thulium p-hydroxybenzenesulfonate complex [Tm(C6H5O4S)2(H2O)6](C6H5O4S)·3H2O (1) was solvothermally synthesized and characterized by elemental analyses, photoluminescence, solid-state UV/vis diffuse reflectance, magnetic measurements and single-crystal X-ray diffraction. Complex 1 features an ionic structure with the thulium ion possessing a square antiprismatic geometry. Complex 1 crystallized in the monoclinic system with space group P21. Photoluminescent measurements with solid-state sample demonstrate that the anti-Stokes emission bands in the red/NIR spectral region 710 and 812 nm are observed from the Tm3+ 4f intrashell transitions from the 3F2,3 excited states to the 3H6 and 1G4 excited state to the 3H5 state, respectively. Solid-state UV/vis diffuse reflectance spectra of complex 1 show the existence of a wide optical band gap of 3.56 eV. Variable-temperature magnetic susceptibility and field dependence magnetization measurements are also studied and the magnetic susceptibility obeys the Curie-Weiss law (χm=c/(T−θ)) with the value C being of 8.6 K and a negative Weiss constant θ being of −0.2 K.

A multinuclear solid-state magnetic resonance study of silver nitrate triphenylphosphine

2005 ◽  
Vol 83 (10) ◽  
pp. 1721-1730 ◽  
Author(s):  
Se-Woung Oh ◽  
Guy M Bernard ◽  
Roderick E Wasylishen ◽  
Robert McDonald ◽  
Michael J Ferguson
Keyword(s):  
Phase Transition ◽  
Solid State ◽  
Single Crystal ◽  
Silver Nitrate ◽  
Solid Phase ◽  
Variable Temperature ◽  
Spin Coupling ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr

Variable-temperature solid-state 31P, 15N, and 2H NMR spectroscopy, X-ray diffraction, and differential scanning calorimetry studies of the 1:1 adduct of silver nitrate and triphenylphosphine (AgNO3·PPh3) reveal a solid–solid phase transition at 300 K. The principal components of the phosphorus and nitrogen chemical shift tensors for both phases are determined from NMR spectra of MAS and stationary samples. In addition, the indirect spin-spin coupling between phosphorus and the naturally occurring isotopes of silver (107Ag and 109Ag) are resolved. Experimental 2H NMR line shapes for silver nitrate perdeuterated triphenylphosphine are those characteristic of rigid phenyl groups at temperatures above and below the phase-transition temperature. Powder and single-crystal X-ray diffraction data for AgNO3·PPh3 obtained at 193, 295, and 313 K are reported; data obtained at 193 and 295 K are almost identical, but are significantly different from those obtained at 313 K and from an earlier single-crystal X-ray diffraction investigation performed at 298 K. All X-ray studies found that AgNO3·PPh3 crystallizes in the monoclinic form, space group P21/c.Key words: 1:1 silver nitrate triphenylphosphine adduct, solid-state NMR, X-ray diffraction, phase transition.

scholarly journals Mechanochemical Syntheses of Isostructural Luminescent Cocrystals of 9-Anthracenecarboxylic Acid with two Dipyridines Coformers

Crystals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 889
Author(s):  
Torvid Feiler ◽  
Biswajit Bhattacharya ◽  
Adam A. L. Michalchuk ◽  
Vincent Schröder ◽  
Emil List-Kratochvil ◽  
...  
Keyword(s):  
Solid State ◽  
Crystal Engineering ◽  
Density Functional ◽  
Photophysical Properties ◽  
Three Dimensional ◽  
Luminescent Materials ◽  
Primary Role ◽  
X Ray Diffraction ◽  
X Ray ◽  
Interpenetrated Structure

Tuning and controlling the solid-state photophysical properties of organic luminophore are very important to develop next-generation organic luminescent materials. With the aim of discovering new functional luminescent materials, new cocrystals of 9-anthracene carboxylic acid (ACA) were prepared with two different dipyridine coformers: 1,2-bis(4-pyridyl)ethylene and 1,2-bis(4-pyridyl)ethane. The cocrystals were successfully obtained by both mechanochemical approaches and conventional solvent crystallization. The newly obtained crystalline solids were characterized thoroughly using a combination of single crystal X-ray diffraction, powder X-ray diffraction, Fourier-transform infrared spectroscopy, differential thermal analysis, and thermogravimetric analysis. Structural analysis revealed that the cocrystals are isostructural, exhibiting two-fold interpenetrated hydrogen bonded networks. While the O–H···N hydrogen bonds adopts a primary role in the stabilization of the cocrystal phases, the C–H···O hydrogen bonding interactions appear to play a significant role in guiding the three-dimensional assembly. Both π···π and C–H···π interactions assist in stabilizing the interpenetrated structure. The photoluminescence properties of both the starting materials and cocrystals were examined in their solid states. All the cocrystals display tunable photophysical properties as compared to pure ACA. Density functional theory simulations suggest that the modified optical properties result from charge transfers between the ACA and coformer molecules in each case. This study demonstrates the potential of crystal engineering to design solid-state luminescence switching materials through cocrystallization.

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