Topological analysis of metal–ligand and hydrogen bonds in transition metal hybrid structures – A computational study

Polyhedron ◽  
2016 ◽  
Vol 115 ◽  
pp. 193-203 ◽  
Author(s):  
Subramaniam Kavitha ◽  
Palanisamy Deepa ◽  
Mylsamy Karthika ◽  
Ramasamy Kanakaraju
Keyword(s):  
Transition Metal ◽  
Hydrogen Bonds ◽  
Computational Study ◽  
Topological Analysis ◽  
Hybrid Structures ◽  
Metal Ligand

scholarly journals How bulk and surface properties of Ti4SiC3, V4SiC3, Nb4SiC3 and Zr4SiC3 tune reactivity: A computational study

2021 ◽  
Author(s):  
Matthew Quesne ◽  
C. Richard A. Catlow ◽  
Nora Henriette De Leeuw
Keyword(s):  
Carbon Dioxide ◽  
Transition Metal ◽  
Surface Properties ◽  
In Silico ◽  
Computational Study ◽  
Max Phase ◽  
Early Transition Metal ◽  
Silicon Carbides ◽  
Carbon Dioxide Hydrogenation ◽  
Early Transition

We present several in silico insights into the MAX-phase of early transition metal silicon carbides and explore how these affect carbon dioxide hydrogenation. Periodic desity functional methodology is applied to...

ChemInform Abstract: Fragmentation of Realgar, As4S4, Controlled by Transition Metal-Ligand Systems.

ChemInform ◽  
1987 ◽  
Vol 18 (51) ◽  
Author(s):  
M. DI VAIRA ◽  
P. STOPPIONI ◽  
M. PERUZZINI
Keyword(s):  
Transition Metal ◽  
Metal Ligand

Symmetry Violations in Partially Oxidized One-Dimensional (1D)Transition Metal Polymers. Metal-Ligand-Metal(M-L-M) Bridged Systems

1984 ◽  
Vol 39 (9) ◽  
pp. 807-829
Author(s):  
Michael C. Böhm
Keyword(s):  
Transition Metal ◽  
Density Wave ◽  
Tight Binding ◽  
Mean Field ◽  
Valence Bond ◽  
Hole State ◽  
One Dimensional ◽  
Metal Derivatives ◽  
A Charge ◽  
Metal Ligand

The band structure of the metal-ligand-metal (M-L-M) bridged quasi one-dimensional (1D) cyclopentadienylmanganese polymer, MnCp 1, has been studied in the unoxidized state and in a partly oxidized modification with one electron removed from each second MnCp fragment. The tight-binding approach is based on a semiempirical self-consistent-field (SCF) Hartree-Fock (HF) crystal orbital (CO) model of the INDO-type (intermediate neglect of differential overlap) combined with a statistical averaging procedure which has its origin in the grand canonical ensemble. The latter approximation allows for an efficient investigation of violations of the translation symmetries in the oxidized 1D material. The oxidation process in 1 is both ligand- and metal-centered (Mn 3d-2 states). The mean-field minimum corresponds to a charge density wave (CDW) solution with inequivalent Mn sites within the employed repeat-units. The symmetry adapted solution with electronically identical 3d centers is a maximum in the variational space. The coupling of this electronic instability to geometrical deformations is also analyzed. The ligand amplitudes encountered in the hole-state wave function prevent extremely large charge separations between the 3d centers which are found in ID systems without bridging moieties (e.g. Ni(CN)2-5 chain). The symmetry reduction in oxidized 1 is compared with violations of spatial symmetries in finite transition metal derivatives and simple solids. The stabilization of the valence bond-type (VB) solution is physically rationalized (i.e. left-right correlations between the 3d centers). The computational results derived for 1 are generalized to oxidized transition metal chains with band occupancies that are simple fractions of the number of stacking units and to 1D systems that deviate from this relation. The entropy-influence for temperatures T ≠ 0 is shortly discussed (stabilization of domain or cluster structures).

Thermal-induced transformation of glutamic acid to pyroglutamic acid and self-cocrystallization: a charge–density analysis

2022 ◽  
Vol 78 (2) ◽  
Author(s):  
Sehrish Akram ◽  
Arshad Mehmood ◽  
Sajida Noureen ◽  
Maqsood Ahmed
Keyword(s):  
Hydrogen Bonds ◽  
Glutamic Acid ◽  
Single Crystal ◽  
Diffraction Data ◽  
Density Functional ◽  
Quantitative Estimation ◽  
Topological Analysis ◽  
Pyroglutamic Acid ◽  
X Ray Diffraction ◽  
X Ray

Thermal-induced transformation of glutamic acid to pyroglutamic acid is well known. However, confusion remains over the exact temperature at which this happens. Moreover, no diffraction data are available to support the transition. In this article, we make a systematic investigation involving thermal analysis, hot-stage microscopy and single-crystal X-ray diffraction to study a one-pot thermal transition of glutamic acid to pyroglutamic acid and subsequent self-cocrystallization between the product (hydrated pyroglutamic acid) and the unreacted precursor (glutamic acid). The melt upon cooling gave a robust cocrystal, namely, glutamic acid–pyroglutamic acid–water (1/1/1), C5H7NO3·C5H9NO4·H2O, whose structure has been elucidated from single-crystal X-ray diffraction data collected at room temperature. A three-dimensional network of strong hydrogen bonds has been found. A Hirshfeld surface analysis was carried out to make a quantitative estimation of the intermolecular interactions. In order to gain insight into the strength and stability of the cocrystal, the transferability principle was utilized to make a topological analysis and to study the electron-density-derived properties. The transferred model has been found to be superior to the classical independent atom model (IAM). The experimental results have been compared with results from a multipolar refinement carried out using theoretical structure factors generated from density functional theory (DFT) calculations. Very strong classical hydrogen bonds drive the cocrystallization and lend stability to the resulting cocrystal. Important conclusions have been drawn about this transition.

Trapping and sensing of hazardous insecticides by chemically modified single walled carbon nanotubes

2017 ◽  
Vol 19 (35) ◽  
pp. 24059-24066 ◽  
Author(s):  
Arkamita Bandyopadhyay ◽  
Dibyajyoti Ghosh ◽  
Swapan K. Pati
Keyword(s):  
Carbon Nanotubes ◽  
Transition Metal ◽  
Computational Study ◽  
Single Walled Carbon Nanotubes ◽  
Ambient Condition ◽  
Nitrogen Doped ◽  
Chemically Modified ◽  
Nitrogen Doped Carbon ◽  
Walled Carbon Nanotubes ◽  
Incorporated Nitrogen

Computational study demonstrates transition metal incorporated nitrogen doped carbon nanotubes can efficiently trap various harmful insecticides at ambient condition.

Redshift or Adduct Stabilization—A Computational Study of Hydrogen Bonding in Adducts of Protonated Carboxylic Acids

2009 ◽  
Vol 15 (2) ◽  
pp. 239-248 ◽  
Author(s):  
Solveig Gaarn Olesen ◽  
Steen Hammerum
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Bond Strength ◽  
Bond Length ◽  
Carboxylic Acids ◽  
Computational Study ◽  
Proton Affinities ◽  
Oh Groups ◽  
Hydrogen Bond Strength ◽  
Length Changes

It is generally expected that the hydrogen bond strength in a D–H•••A adduct is predicted by the difference between the proton affinities (Δ PA) of D and A, measured by the adduct stabilization, and demonstrated by the infrared (IR) redshift of the D–H bond stretching vibrational frequency. These criteria do not always yield consistent predictions, as illustrated by the hydrogen bonds formed by the E and Z OH groups of protonated carboxylic acids. The Δ PA and the stabilization of a series of hydrogen bonded adducts indicate that the E OH group forms the stronger hydrogen bonds, whereas the bond length changes and the redshift favor the Z OH group, matching the results of NBO and AIM calculations. This reflects that the thermochemistry of adduct formation is not a good measure of the hydrogen bond strength in charged adducts, and that the ionic interactions in the E and Z adducts of protonated carboxylic acids are different. The OH bond length and IR redshift afford the better measure of hydrogen bond strength.

scholarly journals Weak Hydrogen Bonds in Some Six- and Five-atom Interactions: An AIM Topological Analysis

2013 ◽  
Vol 2 (6) ◽  
pp. 343-346 ◽  
Author(s):  
Francisco Sánchez-Viesca ◽  
Fernando Cortés ◽  
Reina Gómez ◽  
Martha Berros
Keyword(s):  
Hydrogen Bonds ◽  
Topological Analysis ◽  
Weak Hydrogen Bonds
Sign in / Sign up

Export Citation Format

Share Document