Computational characterization of organometallic ligands coordinating metal: Case of azopyridine ligands

2015 ◽  
Vol 14 (01) ◽  
pp. 1550006 ◽  
Author(s):  
Sopi Thomas Affi ◽  
Kafoumba Bamba ◽  
Nahossé Ziao
Keyword(s):  
Density Functional ◽  
Membered Ring ◽  
Condensed Phases ◽  
Functional Theory ◽  
H Nmr ◽  
Metal Case ◽  
Azo Group ◽  
Hydrogen Bond Basicity ◽  
Pyridinic Nitrogen

Azpy (2-phenylazopyridine), Nazpy (2-pyridylazonaphtol), Mazpy (2,6-diméthyl-2-phenylazopyridine) and Dazpy (2-phenylazo-4,6-dimethylpyridine) are four pyridylazo ligands that are characterized by density functional theory (DFT) theoretical investigation either in gas or in condensed phases. As they display at least three heteroatoms donors of electrons, hydrogen bond basicity has been experimented via energy and geometrical descriptors to determine which of the donors will link to metal so as to form metallic complexes. The pyridinic Nitrogen ( N py ) and that close to the substituent linked to azo group ( N 2) are the most available with almost the same energy to authorize coordination with metal. Before, prediction of Azpy synthesis was undertaken. 1H NMR was also performed. They showed that the conformational trans or E2-azpy was the most stable existing ligand. Nonetheless, this structure undergoes a modification on behalf of the conformational cis or E1-azpy that is the suitable ligand to provide with two nitrogen atoms with the same energy. Regarding this observation, all calculations were undertaken on the conformational E1 of each pyridylazo ligand. Therefore, the results obtained were consistent with the experimental analysis confirming that all of the four ligands are bidentates. In consequence, all the pyridylazo ligands can be assumed to connect to the metal by two nitrogen atoms forming five membered ring regardless the azo group's substituent nature.

MODELING OF INTERFACIAL BEHAVIOR OF WATER AND ORGANICS

2013 ◽  
Vol 12 (07) ◽  
pp. 1350059 ◽  
Author(s):  
VLADIMIR M. GUN'KO
Keyword(s):  
Density Functional ◽  
Bound Water ◽  
Water Structure ◽  
Structural Features ◽  
Bulk Water ◽  
Interfacial Water ◽  
Interfacial Behavior ◽  
Functional Theory ◽  
H Nmr

Modeling of water structure at a surface of different adsorbents, as well as an influence of dissolved compounds or co-adsorbates on bound water, is of importance to understand the temperature dependence of the characteristics of bound water, especially at T < 273 K, in comparison with bulk water. 1 H NMR spectra giving useful information on the water structure can be obtained using different ways such as experimental measurements, direct ab initio and density functional theory (DFT) calculations or estimation using semiempirical calculations and appropriate calibration functions. Here, application of the last approach is analyzed with respect to a variety of relatively large hydrated systems. Despite the simplicity of this approach, it gives quantitative characterization of structural features of interfacial water and effects of different co-adsorbates and adsorbent surfaces on bound water.

scholarly journals On the Many-Body Expansion of an Interaction Energy of Some Supramolecular Halogen-Containing Capsules

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4431
Author(s):  
Jiří Czernek ◽  
Jiří Brus
Keyword(s):  
Density Functional ◽  
Condensed Phases ◽  
Multicomponent Mixtures ◽  
Many Body ◽  
Symmetric Form ◽  
Functional Theory ◽  
Emergent Features ◽  
The Many ◽  
Surprising Fact ◽  
Dimethyl Benzene

A tetramer model was investigated of a remarkably stable iodine-containing supramolecular capsule that was most recently characterized by other authors, who described emergent features of the capsule’s formation. In an attempt to address the surprising fact that no strong pair-wise interactions between any of the respective components were experimentally detected in condensed phases, the DFT (density-functional theory) computational model was used to decompose the total stabilization energy as a sum of two-, three- and four-body contributions. This model considers complexes formed between either iodine or bromine and the crucial D4h-symmetric form of octaaryl macrocyclic compound cyclo[8](1,3-(4,6-dimethyl)benzene that is surrounded by arenes of a suitable size, namely, either corannulene or coronene. A significant enthalpic gain associated with the formation of investigated tetramers was revealed. Furthermore, it is shown that the total stabilization of these complexes is dominated by binary interactions. Based on these findings, comments are made regarding the experimentally observed behavior of related multicomponent mixtures.

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.

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.

Phosphoramides bearing isoxazole derivative: spectroscopic and structural characterization, study of hydrogen-bonding interactions and two lanthanide complexes (LnIII= Ce and Eu)

2015 ◽  
Vol 71 (2) ◽  
pp. 176-185 ◽  
Author(s):  
Khodayar Gholivand ◽  
Foroogh Molaei ◽  
Mahdieh Hosseini
Keyword(s):  
Lanthanide Complexes ◽  
Density Functional ◽  
Spectroscopic Characterization ◽  
Crystalline Lattice ◽  
Ligand Interaction ◽  
Functional Theory ◽  
X Ray Crystallography ◽  
Isoxazole Derivative ◽  
Characterization Study

In this study, the synthesis and spectroscopic characterization of new phosphoramides based on 3-amino-5-methylisoxazole with the formulaR2P(O)[NH–C4H4NO],R= C6H5O (1), C6H5(2),RP(O)[NH—C4H4NO]2,R= C6H5O (3), CH3—C6H4O (4), C6H5NH (5), (C6H5)ClP(O)[NH–C4H4NO] (6) and two lanthanide complexes [Ln(2)2(NO3)3(EtOH)]·EtOH, LnIII= Ce (7) and Eu (8), have been reported. The structural study of (3) shows the presence of two conformers (crystallographically independent molecules) in the crystalline lattice, caused by different orientations of the phenyl and isoxazole rings. For (3), the intermolecular interactions have been studied by Hirshfeld surface analysis and fingerprint plots. Furthermore, the electronic and energy aspects of hydrogen bonds between molecules of (3) have been explored by density functional theory (DFT) calculations. X-ray crystallography of complexes (7) and (8) reveals that two phosphoramide ligands take part in coordination to the metal, one as monodentate from Ophosphoryl, and the other one as chelate through Ophosphoryland Nring. The complexes are also composed of two conformers in the solid-state structure. Quantum theory of atoms in molecules (QTAIM) analysis discloses the electrostatic nature of the Ln–ligand interaction.

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