Lewis acidity of group 14 elements toward intramolecular sulfur in ortho-aryl-thioanisoles

2003 ◽  
Vol 81 (11) ◽  
pp. 1388-1397 ◽  
Author(s):  
Teresita Munguia ◽  
Ioana S Pavel ◽  
Ramesh N Kapoor ◽  
Francisco Cervantes-Lee ◽  
László Párkányi ◽  
...  
Keyword(s):  
Self Assembly ◽  
Silicon Germanium ◽  
Lewis Acidity ◽  
X Ray Diffraction ◽  
Group 14 ◽  
Tetrahedral Geometry ◽  
Triclinic Crystal System ◽  
X Ray ◽  
Distorted Tetrahedral Geometry ◽  
Group 14 Elements

The series of compounds (o-CH3SC6H4)CH2EPh3 (E = Si (1), Ge (2), Sn (3), and Pb (4)) have been synthesized and characterized by NMR spectroscopy and by single crystal X-ray diffraction. Compounds 1 and 2 are isostructural with a triclinic crystal system and P-1 space group; however, morphotropic steps occur between Ge and Sn, and Sn and Pb. While the E-S distances in 1 and 2 are 3.985 and 3.974 Å, respectively, ~100% of the sum of the respective van der Waals (vdW) radii, there is a notable distortion from tetrahedral geometry about E. Compound 3 is also triclinic with P-1 symmetry, but has two molecules in the unit cell that demonstrate a distorted tetrahedral geometry and intramolecular Sn-S distances of 3.699 and 3.829 Å, 88% and 91% of the sum of the vdW radii. Compound 4 has a Pb-S distance of 3.953 Å (91% of Σ vdW radii). The structure of the Grignard coupling product [o-(SCH3)C6H4CH2]2 is also reported.Key words: intramolecular self-assembly, silicon, germanium, tin, lead, sulfur.

Effect of Hydrated Metal Salts on the Coordination Product of Cobalt(II) halide and PNP Type Ligand, 2,6-bis(di-tertbutylphosphinomethyl) pyridine

2018 ◽  
Author(s):  
Tasneem Siddiquee ◽  
Abdul Goni
Keyword(s):  
Metal Salts ◽  
Molar Ratio ◽  
Pincer Complexes ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
Pincer Ligand ◽  
Tetrahedral Geometry ◽  
X Ray ◽  
Distorted Tetrahedral Geometry ◽  
Cobalt Center

Chemical treatment of CoX<sub>2</sub><b><sup>. </sup></b>6H<sub>2</sub>O (X = Cl, Br, I) with the potentially tridentate PNP pincer ligand 2,6-bis(di-<i>tert</i>-butylphosphinomethyl)pyridine in 1:1 molar ratio results in cobalt(II) halide-PNP pincer complexes. The effect of the hydrated metal source on molecular structure and geometry of the complexes was studied by single crystal X-ray diffraction analysis. The complexes are neutral and the cobalt center adopts a penta-coordinate system with potential atropisomerization. Within the unit cell there are two distinct molecules per asymmetric unit. One of the two phosphorus atoms in the PNP ligand was observed to be partially oxidized to phosphinoxide. Disorder in the structure reflects a mixture of square pyramidal and distorted tetrahedral geometry.

[38]Octaphyrin bis-Sn(IV) complexes with unique coordination geometries

2021 ◽  
pp. A-G
Author(s):  
Mondo Izawa ◽  
Akito Nakai ◽  
Taisuke Suito ◽  
Takayuki Tanaka ◽  
Atsuhiro Osuka
Keyword(s):  
Coordination Mode ◽  
Molecular Symmetry ◽  
X Ray Diffraction ◽  
Group 14 ◽  
X Ray ◽  
Aromatic Molecules ◽  
Group 14 Elements ◽  
Cleavage Reactions ◽  
Intramolecular Hydrogen ◽  
Hydrogen Bondings

Metal complexation of octaphyrin(1.1.1.1.1.1.1.1) triggers unique ring-fixation aptitudes or unexpected rearrangement (cleavage) reactions. In this paper, a unique complexation behavior of [38]octaphyrin upon tin(IV) metalation is showcased. Two new [38]octaphyrin bis-Sn(IV) complexes 2Sn and 3Sn were isolated and characterized as weakly aromatic molecules. While 2Sn with the [Formula: see text] molecular symmetry displayed a similar characteristic to octaphyrin bis-Si(IV) and bis-Ge(IV) complexes reported previously, 3Sn showed a different coordination mode that is fixed by intramolecular hydrogen bondings between pyrrolic NH and axially ligated OH on the tin ion as revealed by X-ray diffraction analysis. An unexpected dimeric structure was also observed during an attempt to grow crystals of 2Sn. These characteristic behaviors indicate that the ring-fixation aptitude of octaphyrin is quite sensitive to the nature of metal ions even for the same group 14 elements.

A Spectral and Structural Study of the New Cadmium Salt [(H2L)2][Cd2I6][(NO3)2]

2013 ◽  
Vol 68 (3) ◽  
pp. 272-276 ◽  
Author(s):  
Mohammad Hakimi ◽  
Zahra Mardani ◽  
Keyvan Moeini ◽  
Esther Schuh ◽  
Fabian Mohr
Keyword(s):  
Chair Conformation ◽  
Cyclohexene Oxide ◽  
X Ray Diffraction ◽  
Intermolecular Hydrogen Bonds ◽  
Tetrahedral Geometry ◽  
X Ray ◽  
Distorted Tetrahedral Geometry ◽  
Ft Ir ◽  
Ir And Raman ◽  
Cadmium Salt

The reaction between 2-(piperazin-1-yl)ethanol and cyclohexene oxide under microwave irradiation gave 2-(4-(2-hydroxyethyl)piperazin-1-yl)cyclohexanol (L). The new cadmium salt [(H2L)2][Cd2I6][(NO3)2] (1) was prepared from the reaction of cadmium iodide with L and identified by elemental analysis, FT-IR and Raman spectroscopy, and single-crystal X-ray diffraction. In the crystal structure of 1, there is a [Cd2I6]2- dianion with distorted tetrahedral geometry for each cadmium atom. The piperazine and cyclohexane rings in 1 have a chair conformation. In the crystal there are several intermolecular hydrogen bonds including N-H···O, O-H···O, O-H···I, C-H···O, and C-H···I interactions.

2,6-Bis(benzimidazol-2-yl)pyridine complexes of group 14 elements

2019 ◽  
Vol 48 (22) ◽  
pp. 7835-7843 ◽  
Author(s):  
Ala'aeddeen Swidan ◽  
P. Blake J. St. Onge ◽  
Justin F. Binder ◽  
Riccardo Suter ◽  
Neil Burford ◽  
...  
Keyword(s):  
Lewis Acidity ◽  
Group 14 ◽  
Pyridine Ligand ◽  
X Ray ◽  
X Ray Crystallography ◽  
Pyridine Complexes ◽  
Group 14 Elements

Variants of the 2,6-bis(benzimidazol-2-yl)pyridine ligand are used to synthesize novel group 14 complexes of germanium and tin. The salts are characterized by X-ray crystallography, NMR, UV-vis, and the Lewis acidity of some examples are probed.

scholarly journals Triphenyltin Ortho-Aminophenyl- and 2-Pyridyl-Thiolates: Synthesis and In Vitro Antitumour Activity

1996 ◽  
Vol 3 (2) ◽  
pp. 75-78 ◽  
Author(s):  
Marcel Gielen ◽  
Abdeslam Bouhdid ◽  
Edward R. T. Tiekink ◽  
Dick de Vos ◽  
Rudolph Willem
Keyword(s):  
Cell Lines ◽  
Antitumour Activity ◽  
Spectroscopic Characterization ◽  
X Ray Diffraction ◽  
Tetrahedral Geometry ◽  
X Ray ◽  
Distorted Tetrahedral Geometry ◽  
Monodentate Coordination

The synthesis, spectroscopic characterization and in vitro antitumour activity of two triorganotin compounds, triphenyltin ortho-aminophenylthiolate (1) and triphenyltin 2-pyridylthiolate, compound (2) are reported. The structure of 1 is confirmed by X-ray diffraction, with the tin atom in a distorted tetrahedral geometry because of monodentate coordination, as a thiolate (Sn-S 2.431(2) Å), of the ortho-aminophenylthiolate ligand. The in vitro antitumour activities of 1 and 2, against a number of cell lines, are comparable to those exhibited by methotrexate and doxorubicin, and higher than those of carboplatin and cisplatin.

scholarly journals Crystal Structure of the Protonated Germanide Cluster [HGe9]3−

Crystals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 374 ◽  
Author(s):  
Corinna Lorenz ◽  
Nikolaus Korber
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Diffraction Study ◽  
Liquid Ammonia ◽  
X Ray Diffraction ◽  
Group 14 ◽  
X Ray ◽  
Difference Map ◽  
Group 14 Elements ◽  
Cluster Bonding

A single crystal X-ray diffraction study of the new compound [Rb([2.2.2]crypt)]2[Rb([18]crown−6)][HGe9]·4NH3 revealed the presence of the first protonated nine-atom germanide cluster [HGe9]3−. It forms from Rb4Ge9 in liquid ammonia, so that [Ge9]4− can be considered as the base and [HGe9]3− its formally conjugated acid. The H atom is attached to a germanium vertex atom of the basal square plane, as it is known for [RGe9]3− (R = C5H9, Mes, etc.) or [HE9]3− (E = Si, Sn). In addition, the proton could be located unambiguously in the Fourier difference map. [HGe9]3− also represents a nido cluster species with 22 cluster-bonding electrons, which can be considered the most stable structure for nine-atom cluster species for all group 14 elements.

Effect of Hydrated Metal Salts on the Coordination Product of Cobalt(II) halide and PNP Type Ligand, 2,6-bis(di-tertbutylphosphinomethyl) pyridine

2018 ◽  
Author(s):  
Tasneem Siddiquee ◽  
Abdul Goni
Keyword(s):  
Metal Salts ◽  
Molar Ratio ◽  
Pincer Complexes ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
Pincer Ligand ◽  
Tetrahedral Geometry ◽  
X Ray ◽  
Distorted Tetrahedral Geometry ◽  
Cobalt Center

Chemical treatment of CoX<sub>2</sub><b><sup>. </sup></b>6H<sub>2</sub>O (X = Cl, Br, I) with the potentially tridentate PNP pincer ligand 2,6-bis(di-<i>tert</i>-butylphosphinomethyl)pyridine in 1:1 molar ratio results in cobalt(II) halide-PNP pincer complexes. The effect of the hydrated metal source on molecular structure and geometry of the complexes was studied by single crystal X-ray diffraction analysis. The complexes are neutral and the cobalt center adopts a penta-coordinate system with potential atropisomerization. Within the unit cell there are two distinct molecules per asymmetric unit. One of the two phosphorus atoms in the PNP ligand was observed to be partially oxidized to phosphinoxide. Disorder in the structure reflects a mixture of square pyramidal and distorted tetrahedral geometry.

[Bis(3-methyl-2-thioxo-2,3-dihydro-1H-imidazolyl)borato-κ2 S,S′]dibromoindium(III)

2006 ◽  
Vol 62 (4) ◽  
pp. m702-m704 ◽  
Author(s):  
Sarah C. Hill ◽  
Daniel S. Jones ◽  
Daniel Rabinovich
Keyword(s):  
Solid State ◽  
Single Crystal ◽  
Bond Length ◽  
Title Compound ◽  
Bond Distance ◽  
Mirror Plane ◽  
X Ray Diffraction ◽  
Tetrahedral Geometry ◽  
X Ray ◽  
Distorted Tetrahedral Geometry

The structure of the title compound, [InBr2(C8H12N4BS2)], the first bis(mercaptoimidazolyl)borate (BmMe) complex of indium to be structurally characterized, has been determined by single-crystal X-ray diffraction. The four-coordinate In atom displays a distorted tetrahedral geometry in the solid state and is surrounded by the two thione groups of a BmMe ligand and two bromides, with an average In—Br bond distance of 2.494 Å. The presence of a crystallographically imposed mirror plane results in the observation of a unique In—S bond length of 2.4407 (11) Å.

Electron Microscopy of Human Gallstones

1971 ◽  
Vol 29 ◽  
pp. 296-297
Author(s):  
C. Wolpers ◽  
R. Blaschke
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Bile Pigment ◽  
X Ray Diffraction ◽  
Triclinic Crystal System ◽  
X Ray ◽  
Follow Up Study ◽  
Infra Red ◽  
Main Components

Scanning microscopy was used to study the surface of human gallstones and the surface of fractures. The specimens were obtained by operation, washed with water, dried at room temperature and shadowcasted with carbon and aluminum. Most of the specimens belong to patients from a series of X-ray follow-up study, examined during the last twenty years. So it was possible to evaluate approximately the age of these gallstones and to get information on the intensity of growing and solving.Cholesterol, a group of bile pigment substances and different salts of calcium, are the main components of human gallstones. By X-ray diffraction technique, infra-red spectroscopy and by chemical analysis it was demonstrated that all three components can be found in any gallstone. In the presence of water cholesterol crystallizes in pane-like plates of the triclinic crystal system.

scholarly journals Pyrene Carboxylate Ligand Based Coordination Polymers for Microwave-Assisted Solvent-Free Cyanosilylation of Aldehydes

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1101
Author(s):  
Anirban Karmakar ◽  
Anup Paul ◽  
Elia Pantanetti Sabatini ◽  
M. Fátima C. Guedes da Silva ◽  
Armando J. L. Pombeiro
Keyword(s):  
Coordination Polymer ◽  
Single Crystal ◽  
Coordination Polymers ◽  
Metal Ion ◽  
Solvent Free ◽  
Lewis Acidity ◽  
Carboxylate Ligand ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microwave Assisted

The new coordination polymers (CPs) [Zn(μ-1κO1:1κO2-L)(H2O)2]n·n(H2O) (1) and [Cd(μ4-1κO1O2:2κN:3,4κO3-L)(H2O)]n·n(H2O) (2) are reported, being prepared by the solvothermal reactions of 5-{(pyren-4-ylmethyl)amino}isophthalic acid (H2L) with Zn(NO3)2.6H2O or Cd(NO3)2.4H2O, respectively. They were synthesized in a basic ethanolic medium or a DMF:H2O mixture, respectively. These compounds were characterized by single-crystal X-ray diffraction, FTIR spectroscopy, thermogravimetric and elemental analysis. The single-crystal X-ray diffraction analysis revealed that compound 1 is a one dimensional linear coordination polymer, whereas 2 presents a two dimensional network. In both compounds, the coordinating ligand (L2−) is twisted due to the rotation of the pyrene ring around the CH2-NH bond. In compound 1, the Zn(II) metal ion has a tetrahedral geometry, whereas, in 2, the dinuclear [Cd2(COO)2] moiety acts as a secondary building unit and the Cd(II) ion possesses a distorted octahedral geometry. Recently, several CPs have been explored for the cyanosilylation reaction under conventional conditions, but microwave-assisted cyanosilylation of aldehydes catalyzed by CPs has not yet been well studied. Thus, we have tested the solvent-free microwave-assisted cyanosilylation reactions of different aldehydes, with trimethylsilyl cyanide, using our synthesized compounds, which behave as highly active heterogeneous catalysts. The coordination polymer 1 is more effective than 2, conceivably due to the higher Lewis acidity of the Zn(II) than the Cd(II) center and to a higher accessibility of the metal centers in the former framework. We have also checked the heterogeneity and recyclability of these coordination polymers, showing that they remain active at least after four recyclings.

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