Conformational Analysis of Alkali Metal Salts of a Synthetic Carboxylic Ionophore by NMR Spectroscopy in Combination with X-ray Crystallography

1995 ◽  
Vol 117 (27) ◽  
pp. 7238-7244 ◽  
Author(s):  
Noriko C. Kasuga ◽  
Hitoshi Kuboniwa ◽  
Seiichi Nakahama ◽  
Kazuo Yamaguchi
Keyword(s):  
Nmr Spectroscopy ◽  
Alkali Metal ◽  
Conformational Analysis ◽  
Metal Salts ◽  
Alkali Metal Salts ◽  
X Ray ◽  
X Ray Crystallography

scholarly journals Peering into buried interfaces with X-rays and electrons to unveil MgCO3 formation during CO2 capture in molten salt-promoted MgO

2021 ◽  
Vol 118 (26) ◽  
pp. e2103971118
Author(s):  
Alexander H. Bork ◽  
Margarita Rekhtina ◽  
Elena Willinger ◽  
Pedro Castro-Fernández ◽  
Jakub Drnec ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Alkali Metal ◽  
Growth Mechanism ◽  
Lattice Mismatch ◽  
Model System ◽  
Metal Salts ◽  
X Rays ◽  
Alkali Metal Salts ◽  
Capture Process ◽  
X Ray

The addition of molten alkali metal salts drastically accelerates the kinetics of CO2 capture by MgO through the formation of MgCO3. However, the growth mechanism, the nature of MgCO3 formation, and the exact role of the molten alkali metal salts on the CO2 capture process remain elusive, holding back the development of more-effective MgO-based CO2 sorbents. Here, we unveil the growth mechanism of MgCO3 under practically relevant conditions using a well-defined, yet representative, model system that is a MgO(100) single crystal coated with NaNO3. The model system is interrogated by in situ X-ray reflectometry coupled with grazing incidence X-ray diffraction, scanning electron microscopy, and high-resolution transmission electron microscopy. When bare MgO(100) is exposed to a flow of CO2, a noncrystalline surface carbonate layer of ca. 7-Å thickness forms. In contrast, when MgO(100) is coated with NaNO3, MgCO3 crystals nucleate and grow. These crystals have a preferential orientation with respect to the MgO(100) substrate, and form at the interface between MgO(100) and the molten NaNO3. MgCO3 grows epitaxially with respect to MgO(100), and the lattice mismatch between MgCO3 and MgO is relaxed through lattice misfit dislocations. Pyramid-shaped pits on the surface of MgO, in proximity to and below the MgCO3 crystals, point to the etching of surface MgO, providing dissolved [Mg2+…O2–] ionic pairs for MgCO3 growth. Our studies highlight the importance of combining X-rays and electron microscopy techniques to provide atomic to micrometer scale insight into the changes occurring at complex interfaces under reactive conditions.

M[P(1,2-O2C6H4)3] (M = K or Na) — Synthesis, characterization, and use in halide abstraction

2012 ◽  
Vol 90 (7) ◽  
pp. 574-583 ◽  
Author(s):  
Paul W. Siu ◽  
Derek P. Gates
Keyword(s):  
Crystal Structure ◽  
Alkali Metal ◽  
Crystallographic Analysis ◽  
Molecular Structures ◽  
The Other ◽  
Metal Salts ◽  
Alkali Metal Salts ◽  
Phosphate Anion ◽  
X Ray ◽  
Outside Diameter

Alkali metal salts of the tris(o-phenylenedioxy)phosphate anion, K[P(1,2-O2C6H4)3] (K[1]) and Na[P(1,2-O2C6H4)3] (Na[1]), were prepared by treating Et3NH[1] with KH or NaH, respectively. X-ray crystallographic analysis of K[1], crystallized in the presence of DMSO, revealed a dimeric structure of formulation K2(DMSO)6[1]2·C7H8. In contrast, the crystal structure of K[1] grown from MeCN consists of fascinating hexagonal macrocycles with formulation {K(MeCN)2[1]}6 with an outside diameter of about 25 Å and a very small hole (≤2.5 Å). Remarkably, these hexagonal macrocycles stack one upon the other with a spacing of about 9.4 Å. The salt, K[1], is an effective halide abstraction agent reacting with (dppp)PdCl2 (dppp = 1,3-bis(diphenylphosphino)propane) (1:1 ratio) or [(cod)RhCl]2 (2:1 ratio) to afford [(dppp)Pd(µ-Cl)]2[1]2 and (cod)Rh[1], respectively. The molecular structures of each complex were determined.

scholarly journals Peering into Buried Interfaces with X-Rays and Electrons to Unveil MgCO3 Formation During CO2 Capture in Molten Salt Promoted MgO

2021 ◽  
Author(s):  
Alexander Hansen Bork ◽  
Margarita Rekhtina ◽  
Elena Willinger ◽  
Pedro Castro-Fernández ◽  
Jakub Drnec ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Alkali Metal ◽  
Growth Mechanism ◽  
Co2 Capture ◽  
Model System ◽  
Metal Salts ◽  
X Rays ◽  
Alkali Metal Salts ◽  
Capture Process ◽  
X Ray

<p>The addition of molten alkali metal salts drastically accelerates the kinetics of CO<sub>2</sub> capture by MgO through the formation of MgCO<sub>3</sub>. However, the growth mechanism, the nature of MgCO<sub>3</sub> formation and the exact role of the molten alkali metal salts on the CO2 capture process remains elusive, holding back the development of more effective MgO-based CO<sub>2</sub> sorbents. Here, we unveil the growth mechanism of MgCO<sub>3</sub> under practically relevant conditions using a well-defined, yet representative, model system that is a MgO(100) single crystal coated with NaNO<sub>3</sub>. The model system is interrogated by in situ X-ray reflectometry coupled with grazing incidence X-ray diffraction, scanning electron microscopy and high-resolution transmission electron microscopy. When bare MgO(100) is exposed to a flow of CO<sub>2</sub>, a non-crystalline surface carbonate layer of ca. 7 Å thickness forms. In contrast, when MgO(100) is coated with NaNO<sub>3</sub> MgCO<sub>3</sub> crystals nucleate and growth. These crystals have a preferential orientation with respect to the MgO(100) substrate, and form at the interface between MgO(100) and the molten NaNO<sub>3</sub>. MgCO<sub>3</sub> grows epitaxially with respect to MgO(100) and the lattice mismatch between MgCO<sub>3</sub> and MgO is relaxed through lattice misfit dislocations. Pyramid shaped pits on the surface of MgO, in the proximity and below the MgCO<sub>3</sub> crystals, point to the etching of surface MgO, providing dissolved [Mg<sup>2+</sup>…O<sup>2–</sup>] ionic pairs for MgCO<sub>3</sub> growth. Our studies highlight the importance of combining X-rays and electron microscopy techniques to provide atomic to micrometer scale insight into the changes occurring at complex interfaces under reactive conditions.</p>

Single-crystal X-ray studies of five alkali metal salts of luminol

2013 ◽  
Vol 66 (21) ◽  
pp. 3722-3739 ◽  
Author(s):  
Ilia A. Guzei ◽  
Myoung-Hee Kim ◽  
Robert West
Keyword(s):  
Alkali Metal ◽  
Single Crystal ◽  
Metal Salts ◽  
Alkali Metal Salts ◽  
X Ray

Synthesis and Reactivity of Novel Alkali Metal Stannides

2004 ◽  
Vol 59 (11-12) ◽  
pp. 1462-1470 ◽  
Author(s):  
Thorsten Schollmeier ◽  
Ulrich Englich ◽  
Roland Fischer ◽  
Ingo Prass ◽  
Karin Ruhlandt ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Alkali Metal ◽  
Synthesis And Characterization ◽  
Metal Compounds ◽  
X Ray ◽  
X Ray Crystallography ◽  
Multinuclear Nmr Spectroscopy ◽  
Alkali Metal Compounds ◽  
Potassium Hydride

Reactivity and side products of reactions of diorganodihydridostannanes (R2SnH2, R = Me, nBu, tBu)) with various alkali metal compounds have been discussed. Alternatively, the synthesis and characterization of a family of novel potassium stannides are described as well. The compounds of type (RR’2Si)R”2SnK (R, R’= Me, Ph; R”= , Me, tBu, Ph) 4 - 9 were synthesized by reaction of potassium hydride with bis(silyl)stannides ((RR’2Si)2SnR”2). All compounds were characterized by multinuclear NMR spectroscopy. In addition, the tri-tert-butyltin compound 3 (LiSntBu3) and the unsymmetrical silyl substituted stannane 10 were characterized by X-ray crystallography.

The Tyrosine Gate of the Bacterial Lectin FimH: A Conformational Analysis by NMR Spectroscopy and X-ray Crystallography

ChemBioChem ◽  
2015 ◽  
Vol 16 (8) ◽  
pp. 1235-1246 ◽  
Author(s):  
Brigitte Fiege ◽  
Said Rabbani ◽  
Roland C. Preston ◽  
Roman P. Jakob ◽  
Pascal Zihlmann ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Conformational Analysis ◽  
X Ray ◽  
X Ray Crystallography
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