scholarly journals Solution structure of zinc-seamed C-alkylpyrogallol[4]arene dimeric nanocapsules

RSC Advances ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 3342-3345
Author(s):  
Harshita Kumari ◽  
Wei G. Wycoff ◽  
Collin M. Mayhan ◽  
Steven R. Kline ◽  
Joshua R. So ◽  
...  
Keyword(s):  
Solid State ◽  
Solution Structure ◽  
Solvent Molecules ◽  
Ligands Exchange

Solid-state core geometry of zinc-seamed C-propylpyrogallol[4]arene dimers is retained in solution; however, external ligands exchange with solvent molecules.

scholarly journals 1,1′,3,3′-Tetramesitylquinobis(imidazole)-2,2′-dithione

IUCrData ◽  
2019 ◽  
Vol 4 (9) ◽  
Author(s):  
Jayaraman Selvakumar ◽  
Kuppuswamy Arumugam
Keyword(s):  
Crystal Structure ◽  
Molecular Weight ◽  
Solid State ◽  
Structural Analysis ◽  
Hydrogen Bonds ◽  
Cell Volume ◽  
Title Compound ◽  
Unit Cell Volume ◽  
Density Peaks ◽  
Solvent Molecules

The solid-state structural analysis of the title compound [systematic name: 5,11-disulfanylidene-4,6,10,12-tetrakis(2,4,6-trimethylphenyl)-4,6,10,12-tetraazatricyclo[7.3.0.03,7]dodeca-1(9),3(7)-diene-2,8-dione], C44H44N4O2S2 [+solvent], reveals that the molecule crystallizes in a highly symmetric cubic space group so that one quarter of the molecule is crystallographically unique, the molecule lying on special positions (two mirror planes, two twofold axes and a center of inversion). The crystal structure exhibits large cavities of 193 Å3 accounting for 7.3% of the total unit-cell volume. These cavities contain residual density peaks but it was not possible to unambiguously identify the solvent therein. The contribution of the disordered solvent molecules to the scattering was removed using a solvent mask and is not included in the reported molecular weight. No classical hydrogen bonds are observed between the main molecules.

scholarly journals Effect of Heterocyclic Ring on LnIII Coordination, Luminescence and Extraction of Diamides of 2,2′-Bipyridyl-6,6′-Dicarboxylic Acid

Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 62 ◽  
Author(s):  
Nataliya E. Borisova ◽  
Alexey V. Ivanov ◽  
Anastasia V. Kharcheva ◽  
Tsagana B. Sumyanova ◽  
Uliana V. Surkova ◽  
...  
Keyword(s):  
Solid State ◽  
Dicarboxylic Acid ◽  
Large Deviation ◽  
Specific Interaction ◽  
Heterocyclic Ring ◽  
Solution Stability ◽  
Solvent Molecules ◽  
Electron Sink ◽  
Structure In Solution ◽  
Eu Complexes

We have synthesized and examined several complexes of lanthanides with diamides of 2,2′-bipyridyl-6,6′-dicarboxylic acid bearing various hetaryl-based side chains for the elucidation of the effect of the heterocycle on the structure and properties of the ligands. The multigram scale methods for the preparation of various N-alkyl-hetaryls and their diamides were developed. The solid state structure of 6-methyl-2-pyridylamide of 2,2′-bipyridyl-6,6′-dicarboxylic acid possesses a flat structure where the conformation is completely different from that previously observed for N-alkylated 2,2′-bipyridyl-6,6′-dicarboxamides and 2,6-pyridinedicarboxamides. The complexes of new ligands were synthesized and NMR and X-Ray studied their structure in solution and solid state. The results demonstrate that complexes possess the same structures both in solid state and in solution. Stability constants of the complexes were less when comparing with dimethyl-substituted diamides, but higher than for unsubstituted dianilide. Contrarily, the extraction ability of 2-pyridyl-diamide is significantly lower than for corresponding anilide. Specific interaction of extractant with solvent molecules, which is not available for electron-sink pyridine amides, can explain this. The luminescence of new Eu complexes was significantly higher than for all previously 2,2′-bipyridyl-6,6′-dicarboxamides and QY reaches 18%. Asymmetry ratios of Eu complexes were 25% higher when compared other complexes with 2,2′-bipyridyl-6,6′-dicarboxamides, which indicates large deviation from the inversion center.

scholarly journals Ultralight-Weight Cellulose Aerogels from NBnMO-Stabilized Lyocell Dopes

2007 ◽  
Vol 2007 ◽  
pp. 1-4 ◽  
Author(s):  
Falk Liebner ◽  
Antje Potthast ◽  
Thomas Rosenau ◽  
Emmerich Haimer ◽  
Martin Wendland
Keyword(s):  
Carbon Dioxide ◽  
Solid State ◽  
Solution Structure ◽  
Supercritical Drying ◽  
Regenerated Cellulose ◽  
Cellulose Content ◽  
Solvent Exchange ◽  
New Materials ◽  
Specific Density ◽  
Regeneration Procedure

Cellulose aerogels are intriguing new materials produced by supercritical drying of regenerated cellulose obtained by solvent exchange of solid Lyocell moldings. FromN-methylmorpholine-N-oxide solutions with cellulose contents between 1 and 12%, dimensionally stable cellulose bodies are produced, in which the solution structure of the cellulose is largely preserved and transferred into the solid state. The specific density and surface of the obtained aerogels range from 0.05 to 0.26 g/cm3and from 172 to 284m2/g, respectively, depending on the cellulose content of the Lyocell dopes and regeneration procedure. A reliable extraction and drying procedure using supercritical carbon dioxide, the advantageous use of NBnMO as stabilizer for the Lyocell dopes, and selected physical properties of the materials is communicated.

Structures and Photochemistry of Inclusion Compounds of 9,10-Dihydro-9,10-ethenoanthracene-11,12-bis(diphenylphosphine Oxide)

1997 ◽  
Vol 53 (2) ◽  
pp. 293-299 ◽  
Author(s):  
T. Y. Fu ◽  
Z. Liu ◽  
G. Olovsson ◽  
J. R. Scheffer ◽  
J. Trotter
Keyword(s):  
Solid State ◽  
Single Crystals ◽  
Crystal Structures ◽  
Inclusion Compounds ◽  
Enantiomeric Excess ◽  
Structural Features ◽  
Host Molecule ◽  
Diphenylphosphine Oxide ◽  
Solvent Molecules

Inclusion complexes of 9,10-dihydro-9,10-etheno-anthracene-11,12-bis(diphenylphosphine oxide) (1) as host are synthesized using a variety of guest solvent molecules and the photochemistry of the host molecule is studied in solution and in the crystalline complexes. The crystal structures of four complexes are determined and correlated with their photochemical reactivity. In each case only one dibenzosemibullvalene photoproduct is obtained in the photolysis. Since three of the complexes studied crystallize in the chiral space group P212121, irradiation of single crystals produces a chiral photoproduct in >90% enantiomeric excess. Determination of the absolute configurations of reactants and products allows elucidation of the key structural features that control the enantiospecific solid-state photorearrangements.

A First Comparison of Solid State and Solution Structure of a Complex between Lanthanum Nitrate and 1,9-Diaza-18-crown-6

2001 ◽  
Vol 3 (3) ◽  
pp. 325-327 ◽  
Author(s):  
Alla K. Shestakova ◽  
Vyacheslav A. Chertkov ◽  
Hans-Jörg Schneider ◽  
Konstantin A. Lysenko
Keyword(s):  
Solid State ◽  
Solution Structure ◽  
Lanthanum Nitrate

Hexapodal pyrazole-based receptors: complexes with ammonium ions and solvent molecules in the solid state

Tetrahedron ◽  
2015 ◽  
Vol 71 (47) ◽  
pp. 8965-8974 ◽  
Author(s):  
Niklas Koch ◽  
Wilhelm Seichter ◽  
Monika Mazik
Keyword(s):  
Solid State ◽  
Ammonium Ions ◽  
Solvent Molecules

Solid-State and Solution Structure of Lanthanide(III) Complexes with a Flexible Py-N6Macrocyclic Ligand

2009 ◽  
Vol 2009 (8) ◽  
pp. 1086-1095 ◽  
Author(s):  
Cristina Núñez ◽  
Marta Mato-Iglesias ◽  
Rufina Bastida ◽  
Alejandro Macías ◽  
Paulo Pérez-Lourido ◽  
...  
Keyword(s):  
Solid State ◽  
Solution Structure

Structure, magnetism and colour in simple bis(phosphine)nickel(II) dihalide complexes: an experimental and theoretical investigation

2013 ◽  
Vol 69 (12) ◽  
pp. 1437-1447 ◽  
Author(s):  
Madeleine Schultz ◽  
Philipp-Nikolaus Plessow ◽  
Frank Rominger ◽  
Laura Weigel
Keyword(s):  
Solid State ◽  
Theoretical Investigation ◽  
Density Functional ◽  
Solution Structure ◽  
Room Temperature ◽  
Energy Surface ◽  
H Nmr ◽  
Square Planar ◽  
Phosphine Complex ◽  
Bright Blue

The complex [1,2-bis(di-tert-butylphosphanyl)ethane-κ2P,P′]diiodidonickel(II), [NiI2(C18H40P2] or (dtbpe-κ2P)NiI2, [dtbpe is 1,2-bis(di-tert-butylphosphanyl)ethane], is bright blue–green in the solid state and in solution, but, contrary to the structure predicted for a blue or green nickel(II) bis(phosphine) complex, it is found to be close to square planar in the solid state. The solution structure is deduced to be similar, because the optical spectra measured in solution and in the solid state contain similar absorptions. In solution at room temperature, no31P{1H} NMR resonance is observed, but the very small solid-state magnetic moment at temperatures down to 4 K indicates that the weak paramagnetism of this nickel(II) complex can be ascribed to temperature independent paramagnetism, and that the complex has no unpaired electrons. The red [1,2-bis(di-tert-butylphosphanyl)ethane-κ2P,P′]dichloridonickel(II), [NiCl2(C18H40P2] or (dtbpe-κ2P)NiCl2, is very close to square planar and very weakly paramagnetic in the solid state and in solution, while the maroon [1,2-bis(di-tert-butylphosphanyl)ethane-κ2P,P′]dibromidonickel(II), [NiBr2(C18H40P2] or (dtbpe-κ2P)NiBr2, is isostructural with the diiodide in the solid state, and displays paramagnetism intermediate between that of the dichloride and the diiodide in the solid state and in solution. Density functional calculations demonstrate that distortion from an ideal square plane for these complexes occurs on a flat potential energy surface. The calculations reproduce the observed structures and colours, and explain the trends observed for these and similar complexes. Although theoretical investigation identified magnetic-dipole-allowed excitations that are characteristic for temperature-independent paramagnetism (TIP), theory predicts the molecules to be diamagnetic.

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