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.

A Novel Alkali-Metal Hydrido-tris(pyrazolyl)borate (Tp*) Complex. Isolation and Crystal Structure of [(Me2CO)3(NaTp*)2]

2014 ◽  
Vol 69 (7) ◽  
pp. 793-798
Author(s):  
Laurent Plasseraud ◽  
Hélène Cattey
Keyword(s):  
Crystal Structure ◽  
Alkali Metal ◽  
Sodium Hydroxide ◽  
Title Compound ◽  
Room Temperature ◽  
Crystallographic Analysis ◽  
Monoclinic Space Group ◽  
Large Excess ◽  
X Ray ◽  
Acetone Water

The title compound was isolated from the treatment of Tp*Sn(Cl)2Bu (1) with a large excess of sodium hydroxide in a mixture of acetone-water at room temperature. [(Me2CO)3(NaTp*)2] (2) crystallizes at 4 °C as prismatic colorless crystals, in the monoclinic space group P21/c with Z = 4, a = 12.2837(6), b = 24.3197(12), c = 16.9547(8) Å, β = 110.017(1)°, and V = 4759.0(4) Å3. The X-ray crystallographic analysis revealed a dinuclear unit in which two Tp*Na moieties are held together by three bridging acetone molecules acting as oxygen-based donors.

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.

Alkali metal complexes having sterically bulky bis-iminopyrrolyl ligands – control of dimeric to monomeric complexes

RSC Advances ◽  
2016 ◽  
Vol 6 (84) ◽  
pp. 80916-80923 ◽  
Author(s):  
Srinivas Anga ◽  
Indrani Banerjee ◽  
Hari Pada Nayek ◽  
Tarun K. Panda
Keyword(s):  
Alkali Metal ◽  
Metal Complexes ◽  
Molecular Structures ◽  
Metal Salts ◽  
Alkali Metal Salts ◽  
Imine Nitrogen ◽  
Alkali Metal Complexes

Alkali metal salts of {(CHPh2)2-pyr} and {(CPh3)2-pyr} were prepared and in the molecular structures of these complexes a nuclearity shift from the dimer to monomer were observed due to the substitutions of CHPh2 to CPh3 groups in imine nitrogen of the ligand.

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>

scholarly journals Stabilization of an elusive tautomer by metal coordination

2021 ◽  
Vol 77 (7) ◽  
Author(s):  
Emmanuele Parisi ◽  
Roberto Centore
Keyword(s):  
Rational Design ◽  
Tautomeric Form ◽  
Crystallographic Analysis ◽  
Molecular Structures ◽  
The Other ◽  
Tetrahedral Geometry ◽  
Coordination Environment ◽  
X Ray ◽  
Triazole Ligand ◽  
Bromide Ion

The solid-state isolation of the different tautomers of a chemical compound can be a challenging problem. In many cases, tautomers with an energy very close to the most stable one cannot be isolated (elusive tautomers). In this article, with reference to the 4-methyl-7-(pyrazin-2-yl)-2H-[1,2,4]triazolo[3,2-c][1,2,4]triazole ligand, for which the elusive 3H-tautomer has an energy only 1.4 kcal mol−1 greater than the most stable 2H form, we show that metal complexation is a successful and reliable way for stabilizing the elusive tautomer. We have prepared two complexes of the neutral ligand with CuBr2 and ZnBr2, namely, aquabromidobis[4-methyl-7-(pyrazin-2-yl)-3H-[1,2,4]triazolo[3,2-c][1,2,4]triazole]copper(II) bromide trihydrate, [CuBr(C8H7N7)2(H2O)]Br·3H2O, and dibromido[4-methyl-7-(pyrazin-2-yl)-2H-[1,2,4]triazolo[3,2-c][1,2,4]triazole][4-methyl-7-(pyrazin-2-yl)-3H-[1,2,4]triazolo[3,2-c][1,2,4]triazole]zinc(II) monohydrate, [ZnBr2(C8H7N7)2]·H2O. The X-ray analysis shows that, in both cases, the elusive 3H-tautomer is present. The results of the crystallographic analysis of the two complexes reflect the different coordination preferences of CuII and ZnII. The copper(II) complex is homotautomeric as it only contains the elusive 3H-tautomer of the ligand. The complex can be described as octahedral with tetragonal distortion. Two 3H-triazolotriazole ligands are bis-chelated in the equatorial plane, while a water molecule and a bromide ion in elongated axial positions complete the coordination environment. The zinc(II) complex, on the other hand, is heterotautomeric and contains two bromide ions and two monodentate ligand molecules, one in the 2H-tautomeric form and the other in the 3H-tautomeric form, both coordinated to the metal in tetrahedral geometry. The observation of mixed-tautomer complexes is unprecedented for neutral ligands. The analysis of the X-ray molecular structures of the two complexes allows the deduction of possible rules for a rational design of mixed-tautomer complexes.

Molecular Structures of the Heavier Alkali Metal Salts of Supermesitylphosphane:  A Systematic Investigation

1998 ◽  
Vol 37 (17) ◽  
pp. 4235-4245 ◽  
Author(s):  
Gerd W. Rabe ◽  
Henrike Heise ◽  
Glenn P. A. Yap ◽  
Louise M. Liable-Sands ◽  
Ilia A. Guzei ◽  
...  
Keyword(s):  
Alkali Metal ◽  
Systematic Investigation ◽  
Molecular Structures ◽  
Metal Salts ◽  
Alkali Metal Salts

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
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