scholarly journals Vibrational Analysis of “Dimethylbipyridinylzinc (0) [C12H14N2Zn]”: A DFT Approach

Author(s):  
Tanveer Hasan ◽  
P. K. Singh ◽  
S. H. Mehdi

Theoretical quantum chemical studies and spectroscopic investigations on “Dimethylbipyridinylzinc (0) C12H14N2Zn” have been carried out. The quantum chemical density functional theory (DFT) method at B3LYP/3-21G level is used to obtain the equilibrium geometries. We have also performed vibrational analysis of the title compound at their equilibrium geometries and established the complete assignments of the significant vibrational modes. The NLO behaviour of the title compound is described by electric parameters like dipole moment, polarizability and first hyperpolarizability. Besides it the thermodynamical and electronic parameters are also calculated to get a better insight of the molecule under study.

Author(s):  
Tanveer Hasan ◽  
P. K. Singh ◽  
S. H. Mehdi

Vibrational investigations along with theoretical quantum chemical studies on “2-Diphenylphosphanyl-6-fluoro-pyridine (C17H14NFP)” have been carried out. The quantum chemical density functional method at B3LYP/3-21Glevel is used to obtain the equilibrium geometries of the title compound. We have also performed vibrational analysis of the title compound at their equilibrium geometries and established the complete assignments of the significant vibrational modes. Electronic parameters such as HOMO, LUMO and frontier orbital energy band gap, has been calculated. Besides it the thermodynamical parameters like internal thermal energy, entropy and constant volume specific heat capacity have been calculated.


Author(s):  
Tanveer Hasan ◽  
P. K. Singh

Spectroscopic investigations along with theoretical quantum chemical studies on “2-Arsanyl-Pyridine (C5H7AsN)” have been carried out. The quantum chemical density functional method at B3LYP/6-31+g(d,p) level, is used to obtain the equilibrium geometries of the title compound. We have also performed vibrational analysis of the title compound at their equilibrium geometries and established the complete assignments of the significant vibrational modes. The calculated vibrational frequencies are shown to be in perfect agreement with the theoretically observed FTIR spectra of the molecule under study.


2012 ◽  
Vol 67 (10) ◽  
pp. 1061-1069 ◽  
Author(s):  
Dieter Hess ◽  
Bernd Hannebauer ◽  
Matthias Königa ◽  
Matthias Reckers ◽  
Stefan Buchholz ◽  
...  

Hydroformylation of 1-butene using a triphenylphosphine-modified iridium catalyst was investigated by operando infrared spectroscopy. The spectra were interpreted by comparison with quantumchemically calculated vibrational spectra at the density functional theory level. The processes during activation of the catalyst and hydroformylation were investigated in detail, and the results are discussed. The recently discovered phenomenon of activity enhancement in iridium-catalyzed hydroformylation by a preceding activation step, in which the reaction mixture is treated with synthesis gas containing an excess of carbon monoxide under pressure, could be correlated with the appearance of a complex HIr(PPh3)(CO)3. The similarities and differences between iridium- and rhodium-catalyzed hydroformylation are discussed.


2015 ◽  
Vol 44 (35) ◽  
pp. 15450-15462 ◽  
Author(s):  
Biswajit Sadhu ◽  
Mahesh Sundararajan ◽  
Gunasekaran Velmurugan ◽  
Ponnambalam Venuvanalingam

Quantum chemical studies predict the binding of Cesium salts to multitopic ion-pair receptor is through cooperative mechanism.


2015 ◽  
Vol 21 (9) ◽  
pp. 2717-2726
Author(s):  
Md. Shahzad Khan ◽  
Md. Mushtaque ◽  
Mohd. Shahid Khan ◽  
Anurag Srivastava ◽  
Kakul Husain

1975 ◽  
Vol 28 (11) ◽  
pp. 2343 ◽  
Author(s):  
RC Haddon

The MINDO/3 SCF MO method has been used to investigate the equilibrium geometries, electronic structure and ground state properties of ply and its univalent ions. The results indicate that ply has a low energy of disproportionation and that electron addition or removal leads to little structural change. From an analysis of the results it is concluded that odd-alternant hydrocarbons, and systems based on the ply nucleus in particular, have many of the characteristics which are considered to be important in the design of organic metals and superconductors.


2020 ◽  
Vol 644 ◽  
pp. A146
Author(s):  
Tao Chen ◽  
Yang Wang

Context. Polycyclic aromatic hydrocarbons (PAHs) and fullerenes are the largest molecules found in the interstellar medium (ISM). They are abundant and widespread in various astronomical environments. However, the detailed connection between these two species is unknown; in particular, no quantum chemical studies have been performed. Aims. In this work, we investigate a vital step in transforming planar PAHs to fullerenes, that is, the tubulation processes of PAHs. Methods. We used density functional theory for this study. The molecular structures and vibrational frequencies were calculated using the hybrid density functional B3LYP method. To better describe intermolecular forces, we considered Grimme’s dispersion correction in the calculations for this work. Intrinsic reaction coordinate calculations were also performed to confirm that the transition state structures are connected to their corresponding local potential energy surface minima. Results. As expected, we find that it is easier to bend a molecule as it gets longer, whereas it is harder to bend the molecule if it gets “wider” (i.e., with more rows of benzene rings). The change of multiplicity slightly alters the bending energies, while (a complete) dehydrogenation alleviates the bending barrier significantly and facilitates the formation of pentagons, which may act as an indispensable step in the formation of fullerenes in the ISM.


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