scholarly journals Synthesis and Characterization of the Germathioacid Chloride Coordinated by an N-Heterocyclic Carbene §

Inorganics ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 76 ◽  
Author(s):  
Yasunobu Egawa ◽  
Chihiro Fukumoto ◽  
Koichiro Mikami ◽  
Nobuhiro Takeda ◽  
Masafumi Unno
Keyword(s):  
Carboxylic Acid ◽  
Density Functional ◽  
Dft Calculation ◽  
Acid Chlorides ◽  
Carboxylic Acid Chloride ◽  
Functional Theory ◽  
Nitrogen Ligands ◽  
Bond Property ◽  
Nitrogen Bonds

Carboxylic acid chlorides are useful substrates in organic chemistry. Many germanium analogues of carboxylic acid chloride have been synthesized so far. Nevertheless, all of the reported germathioacid chlorides use bidentate nitrogen ligands and contain germanium-nitrogen bonds. Our group synthesized germathioacid chloride, Ge(S)Cl{C6H3-2,6-Tip2}(Im-i-Pr2Me2), using N-heterocyclic carbene (Im-i-Pr2Me2). As a result of density functional theory (DFT) calculation, it was found that electrons are localized on sulfur, and the germanium-sulfur bond is a single bond with a slight double bond property.

The Nature of S-N Bonding in Sulfonamides and Related Compounds: Insights into π-Bonding Contributions from Sulfur K-Edge XAS

2020 ◽  
Author(s):  
Tulin Okbinoglu ◽  
Pierre Kennepohl
Keyword(s):  
Density Functional ◽  
Chemical Properties ◽  
Functional Theory ◽  
Rotational Barriers ◽  
Td Dft ◽  
Nitrogen Bonds ◽  
X Ray Absorption ◽  
Related Compounds ◽  
And Chemical Properties

Molecules containing sulfur-nitrogen bonds, like sulfonamides, have long been of interest due to their many uses and chemical properties. Understanding the factors that cause sulfonamide reactivity is important, yet their continues to be controversy regarding the relevance of S-N π bonding in describing these species. In this paper, we use sulfur K-edge x-ray absorption spectroscopy (XAS) in conjunction with density functional theory (DFT) to explore the role of S<sub>3p</sub> contributions to π-bonding in sulfonamides, sulfinamides and sulfenamides. We explore the nature of electron distribution of the sulfur atom and its nearest neighbors and extend the scope to explore the effects on rotational barriers along the sulfur-nitrogen axis. The experimental XAS data together with TD-DFT calculations confirm that sulfonamides, and the other sulfinated amides in this series, have essentially no S-N π bonding involving S<sub>3p</sub> contributions and that electron repulsion and is the dominant force that affect rotational barriers.

scholarly journals Structural and computational investigation of an imine-based propeller-shaped macrocyclic cage

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Sriram Srinivasa Raghvan ◽  
Suresh Madhu ◽  
Velmurugan Devadasan ◽  
Gunasekaran Krishnasamy
Keyword(s):  
Band Gap ◽  
Density Functional ◽  
Strain Tensor ◽  
Strong Interactions ◽  
Soft Condensed Matter ◽  
Functional Theory ◽  
Self Assembling ◽  
Phenyl Rings ◽  
Crystal Volume

AbstractIn this study, we present the synthesis, spectroscopic and structural characterization of self-assembling gem-dimethyl imine based molecular cage (IMC). Self-assembling macrocycles and cages have well-defined cavities and have extensive functionalities ranging from energy storage, liquid crystals, and catalysts to water splitting photo absorber. IMC has large voids i.e., 25% of the total crystal volume thus could accommodate wide substrates. The synthesized imine-based molecular cages are stabilized by coaxial π bonded networks and long-range periodic van der Waal and non-bonded contacts as observed from the crystal structure. IMC also has typical properties of soft condensed matter materials, hence theoretical prediction of stress and strain tensor along with thermophysical properties were computed on crystal system and were found to be stable. Molecular dynamics revealed IMC is stabilized by, strong interactions between the interstitial phenyl rings. Density functional theory (DFT) based physicochemical properties were evaluated and has band gap of around 2.38ev (520 nm) similar to various photocatalytic band gap materials.

scholarly journals Metal-Rich Metallaboranes: Synthesis, Structures and Bonding of Bi- and Trimetallic Open-Faced Cobaltaboranes

Inorganics ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 28
Author(s):  
Kriti Pathak ◽  
Chandan Nandi ◽  
Jean-François Halet ◽  
Sundargopal Ghosh
Keyword(s):  
Electronic Structures ◽  
Density Functional ◽  
Room Temperature ◽  
Electron Pair ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
Cluster 2 ◽  
Cobalt Center

Synthesis, isolation, and structural characterization of unique metal rich diamagnetic cobaltaborane clusters are reported. They were obtained from reactions of monoborane as well as modified borohydride reagents with cobalt sources. For example, the reaction of [Cp*CoCl]2 with [LiBH4·THF] and subsequent photolysis with excess [BH3·THF] (THF = tetrahydrofuran) at room temperature afforded the 11-vertex tricobaltaborane nido-[(Cp*Co)3B8H10] (1, Cp* = η5-C5Me5). The reaction of Li[BH2S3] with the dicobaltaoctaborane(12) [(Cp*Co)2B6H10] yielded the 10-vertex nido-2,4-[(Cp*Co)2B8H12] cluster (2), extending the library of dicobaltadecaborane(14) analogues. Although cluster 1 adopts a classical 11-vertex-nido-geometry with one cobalt center and four boron atoms forming the open pentagonal face, it disobeys the Polyhedral Skeletal Electron Pair Theory (PSEPT). Compound 2 adopts a perfectly symmetrical 10-vertex-nido framework with a plane of symmetry bisecting the basal boron plane resulting in two {CoB3} units bridged at the base by two boron atoms and possesses the expected electron count. Both compounds were characterized in solution by multinuclear NMR and IR spectroscopies and by mass spectrometry. Single-crystal X-ray diffraction analyses confirmed the structures of the compounds. Additionally, density functional theory (DFT) calculations were performed in order to study and interpret the nature of bonding and electronic structures of these complexes.

Effect of Solute Ta on Grain Refinement of Al-7Si-0.3Mg Based Alloys

2022 ◽  
Vol 327 ◽  
pp. 54-64
Author(s):  
Ivo Spacil ◽  
David Holec ◽  
Peter Schumacher ◽  
Jiehua Li
Keyword(s):  
Grain Refinement ◽  
Density Functional ◽  
Dft Calculation ◽  
Interface Energy ◽  
Special Focus ◽  
Grain Refiner ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Sandwich Configuration ◽  
Scanning Electron

Different Ta concentrations together with stochiometric grain refiner (Al-2.2Ti-1B) in Al-Si-Mg based alloys were investigated with the aim to elucidate grain refinement mechanisms. Post-solidification microstructure was characterised using optical microscopy and scanning electron microscopy (SEM), with a special focus on the Ta-rich layer (more likely to be Al3Ta) on the basal planes (0001) of TiB2. A significant grain refinement was observed by using the solute Ta together with stochiometric grain refiner (Al-2.2Ti-1B). In order to further elucidate the formation of Ta-rich layer on the basal planes (0001) of TiB2, the Density Functional Theory (DFT) calculation were also performed to determine the interface energies of different interfaces and sandwich configurations, including Al (111), Al3Ti (112) and Al3Ta (112) at the interface of TiB2 basal plane (0001). It was found that the interface energy for Ti-terminated TiB2 at the interface throughout all configurations involved in this paper is lower than that for B-terminated TiB2, indicating that Ti-terminated TiB2 is more favourable. It was also found that the Al3Ta configuration yields the same interface energies as the Al3Ti configuration. Furthermore, the interface energy of the sandwich configuration also shows nearly identical values along the TiB2 // Al3Ti and TiB2 // Al3Ta interface energy, strongly indicating that the solute Ti can be fully replaced by the solute Ta.

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