Oxazine Ring-Related Vibrational Modes of Benzoxazine Monomers Using Fully Aromatically Substituted, Deuterated, 15N Isotope Exchanged, and Oxazine-Ring-Substituted Compounds and Theoretical Calculations

2017 ◽  
Vol 121 (33) ◽  
pp. 6269-6282 ◽  
Author(s):  
Lu Han ◽  
Daniela Iguchi ◽  
Phwey Gil ◽  
Tyler R. Heyl ◽  
Victoria M. Sedwick ◽  
...  
Keyword(s):  
Theoretical Calculations ◽  
Vibrational Modes ◽  
15N Isotope ◽  
Oxazine Ring

A STUDY OF THE STRUCTURES AND VIBRATIONAL SPECTRA OF THE N2O⋯(HX)2 AND ON2⋯(HX)2 WITH X = F, Cl, Br AND CN

2013 ◽  
Vol 12 (05) ◽  
pp. 1350044 ◽  
Author(s):  
NATHÁLIA B. D. LIMA ◽  
MÁRCIA K. D. L. BELARMINO
Keyword(s):  
Nitrous Oxide ◽  
Vibrational Spectra ◽  
Theoretical Calculations ◽  
Bond Formation ◽  
Binding Energies ◽  
Vibrational Modes ◽  
Out Of Plane ◽  
Usual Behavior ◽  
Bending Modes ◽  
Stable Structures

Theoretical calculations 6-311++G(d,p) have been performed in order to obtain binding energies and molecular properties of complexes involving nitrous oxide ( N2O ) and two HX (X = F, Cl, Br and CN ) molecules. Our calculations have revealed the existence of eleven stable structures. The vibrational changes which take place in the HX acid after complexation follow the usual behavior: the HX stretching frequency is shifted downward whereas its IR intensity is much enhanced. The new vibrational modes arising upon H-bond formation, were verified, especially, those associated with the out-of-plane and in-plane HX bending modes, which are pure rotations in the HX isolated molecule.

scholarly journals Vinblastine and vincristine as anticancer molecules stopping the tubulin dimers

2020 ◽  
Vol 9 (1) ◽  
pp. 870-874
Keyword(s):  
Tyrosine Kinase ◽  
Ligand Binding ◽  
Ir Spectra ◽  
Theoretical Calculations ◽  
Vinca Alkaloid ◽  
Dielectric Constants ◽  
Vibrational Modes ◽  
Cell Surfaces ◽  
Hydrophobic Domain ◽  
Chemical Analogue

Vinblastine is belonging to vinca alkaloid family which is a chemical analogue of vincristine molecules. It has a high potential for attaching to tubulin of microtubules, therefore inhibiting the assembly of that biomolecules. Human EGFRs receptors are cell surfaces receptors proteins including three different domains which are known extracellular ligand-binding domain, trans-membranes hydrophobic domain and cytoplasmic C-terminal domain with tyrosine kinase. The Chemical & physical vibrational spectral data obtained from NMR, NBO and IR spectra based on the results of the theoretical calculations using DFT and HF methods. The fundamental vibrational modes were characterized depending on the stabilities of Herceptin in different dielectric constants. Thus, the goal of this article is to evaluate and quantify and qualify of the mechanism in various solvents.

Theoretical calculations of vibrational modes in endohedral metallofullerenes: La@C82and Sc2@C84

2003 ◽  
Vol 101 (1-2) ◽  
pp. 249-254 ◽  
Author(s):  
KAORU KOBAYASHI ◽  
SHIGERU NAGASE
Keyword(s):  
Theoretical Calculations ◽  
Vibrational Modes ◽  
Endohedral Metallofullerenes

INTERACTIONS OF THz VIBRATIONAL MODES WITH CHARGE CARRIERS IN DNA: POLARON-PHONON INTERACTIONS

2007 ◽  
Vol 17 (02) ◽  
pp. 293-309 ◽  
Author(s):  
DINAKAR RAMADURAI ◽  
TAKAYUKI YAMANAKA ◽  
YANG LI ◽  
MILANA VASUDEV ◽  
VISWANATH SANKAR ◽  
...  
Keyword(s):  
Charge Transport ◽  
Electrical Transport ◽  
Theoretical Calculations ◽  
Charge Trapping ◽  
Directed Assembly ◽  
Charge Carriers ◽  
Vibrational Modes ◽  
Electrical Transport Properties ◽  
One Dimensional ◽  
Phonon Absorption

This paper presents models and experimental measurements that shed light on THz-phonon mediated transport of polarons in biomolecules. Polaron transport in DNA has been considered recently in view of the expected derealization of charge carriers on a one-dimensional wire as well as the highly charged nature of DNA.1,2 An understanding of the electrical transport properties and THz-phonon interactions of biomolecules is important in view of DNA's potential applications both as electrically conductive wires and as structures that facilitate the chemically-directed assembly of massively integrated ensembles of nanoscale semiconducting elements into terascale integrated networks. Moreover, understanding these interactions provides information of the THz spectrum of vibrational modes in DNA. A primary focus of this paper is on charge transport in biomolecules using indirect-bandgap colloidal nanocrystals linked with biomolecules.3 Through a combination of theoretical and experimental approaches,4-7 this paper focuses on understanding the electrical properties and THz-frequency interactions of DNA. Moreover, this paper presents observed charge transport phenomena in DNA and discusses how these measurements are related to carrier scattering from the THz vibrational modes in DNA. Indeed, carrier transport in DNA is analyzed in light of theoretical calculations of the effects of THz-frequency phonon emission by propagating carriers, THz-frequency phonon absorption by propagating and trapped carriers, and effective mass calculations for specific sequences of the DNA bases.1-7 These studies focus on THz-phonon-mediated processes since an extra carrier on a one-dimensional chain minimizes its energy by forming an extended polaron, and since many biomolecules, including DNA, exhibit THz vibrational spectra.8 Accordingly, these calculations focus on THz-phonon-mediated processes. These results are discussed in terms of the role of THz-phonon-mediated charge trapping and detrapping effects near guanine-rich regions of the DNA as well as on the understanding and identification of DNA with specific base sequences that promote charge transport. As in previous studies, optical excitation is used to inject carriers into DNA wires. Moreover, this paper reports on the use of gel electrophoresis to study charge-induced cleavage of DNA and the related transport of charge in DNA. Phonon absorption and emission from polarons in DNA,9 is analyzed using parameters from the well-known Su-Schrieffer-Heeger Hamiltonian.

Theoretical modelling of surface phonons

Open Physics ◽  
2009 ◽  
Vol 7 (2) ◽  
Author(s):  
Gyaneshwar Srivastava ◽  
Huseyin Tütüncü
Keyword(s):  
Density Functional ◽  
Theoretical Calculations ◽  
Group Iv ◽  
Solid Surfaces ◽  
Theoretical Modelling ◽  
Semiconductor Surfaces ◽  
Vibrational Modes ◽  
Phonon Modes ◽  
Surface Phonons ◽  
Bond Charge

AbstractWe present a mini review of progress made towards theoretical modelling of surface phonons. We outline the essential ingredients of two theoretical methods, viz. an adiabatic bond charge method for semiconductor surfaces and the ab-initio density-functional perturbation method for solid surfaces in general. From the results of theoretical calculations we establish trends and criteria for the existence of localized phonon modes on group-IV(001) and III-V(110) semiconductor surfaces. We further obtain signatures of characteristic vibrational modes which develop during dissociative molecular adsorption on Si(001) surfaces. The results are compared with available experimental measurements. Some remarks are forwarded regarding manipulation of surface phonon modes for scientific advances and technological applications.

scholarly journals Charge-sensitive vibrational modes in the (EDT-TTF-OX)2AsF6 chiral molecular conductors

Open Physics ◽  
2014 ◽  
Vol 12 (3) ◽  
Author(s):  
Iwona Olejniczak ◽  
Arkadiusz Frąckowiak ◽  
Jacek Matysiak ◽  
Augustin Madalan ◽  
Flavia Pop ◽  
...  
Keyword(s):  
Density Functional ◽  
Theoretical Calculations ◽  
Charge Ordering ◽  
Racemic Mixture ◽  
Vibrational Modes ◽  
Frequency Range ◽  
Donor Molecule ◽  
Dft Methods ◽  
Molecular Conductors ◽  
Functional Theory

AbstractInfrared and Raman spectra of three chiral molecular conductors (EDT-TTF-OX)2AsF6, comprising of two salts based on enantiopure EDT-TTF-OX donor molecules and one based on their racemic mixture, have been measured as a function of temperature. In the frequency range of the C=C stretching vibrations of EDT-TTF-OX, charge-sensitive modes are identified based on theoretical calculations for neutral and oxidized EDT-TTF-OX using density functional theory (DFT) methods. The positions of C=C stretching modes in both Raman and infrared spectra of the (EDT-TTF-OX)2AsF6 materials are analyzed assuming a linear relationship between the frequency and charge of the molecule. The charge density on the EDTTTF-OX donor molecule is estimated to be +0.5 in all investigated materials and does not change with temperature. Therefore we suggest, that M-I transition observed in (EDT-TTF-OX)2AsF6 chiral molecular conductors at low temperature is not related to the charge ordering mechanism.

Regulating vibrational modes to improve quantum efficiency: insights from theoretical calculations on iridium(iii) complexes bearing tridentate NCN and NNC chelates

2019 ◽  
Vol 48 (15) ◽  
pp. 5064-5071 ◽  
Author(s):  
Yuanqing Lei ◽  
Hao Guo ◽  
Jian Wang ◽  
Ran Jia
Keyword(s):  
Quantum Efficiency ◽  
Theoretical Calculations ◽  
Vibrational Modes

Rational modification of a ligand can boost phosphorescence quantum efficiency.

XUV Absorption Spectra of Carbon Ions

1988 ◽  
Vol 102 ◽  
pp. 71-73
Author(s):  
E. Jannitti ◽  
P. Nicolosi ◽  
G. Tondello
Keyword(s):  
Absorption Spectra ◽  
Cross Section ◽  
Theoretical Calculations ◽  
Photoionization Cross Section ◽  
Carbon Ions

AbstractThe photoabsorption spectra of the carbon ions have been obtained by using two laser-produced plasmas. The photoionization cross-section of the CV has been absolutely measured and the value at threshold, σ=(4.7±0.5) × 10−19cm2, as well as its behaviour at higher energies agrees quite well with the theoretical calculations.

Relative Intensities in ED Patterns From Thin Gold Films

1972 ◽  
Vol 30 ◽  
pp. 636-637
Author(s):  
R. H. Morriss ◽  
J. D. C. Peng ◽  
C. D. Melvin
Keyword(s):  
Theoretical Calculations ◽  
Diffraction Theory ◽  
Gold Films ◽  
Reasonable Accuracy ◽  
Experimental Conditions ◽  
Crystal Perfection ◽  
Heavy Atoms ◽  
Fine Focus ◽  
Convergent Beam ◽  
Beam Diffraction

Although dynamical diffraction theory was modified for electrons by Bethe in 1928, relatively few calculations have been carried out because of computational difficulties. Even fewer attempts have been made to correlate experimental data with theoretical calculations. The experimental conditions are indeed stringent - not only is a knowledge of crystal perfection, morphology, and orientation necessary, but other factors such as specimen contamination are important and must be carefully controlled. The experimental method of fine-focus convergent-beam electron diffraction has been successfully applied by Goodman and Lehmpfuhl to single crystals of MgO containing light atoms and more recently by Lynch to single crystalline (111) gold films which contain heavy atoms. In both experiments intensity distributions were calculated using the multislice method of n-beam diffraction theory. In order to obtain reasonable accuracy Lynch found it necessary to include 139 beams in the calculations for gold with all but 43 corresponding to beams out of the [111] zone.

Effects of Higher-Order Laue Zone reflections on structure images

1993 ◽  
Vol 51 ◽  
pp. 450-451
Author(s):  
H. S. Kim ◽  
S. S. Sheinin
Keyword(s):  
Wave Vector ◽  
Theoretical Calculations ◽  
Reciprocal Lattice ◽  
Image Plane ◽  
Bloch Wave ◽  
Dynamical Theory ◽  
Higher Order ◽  
Lattice Image ◽  
Lattice Vector ◽  
Image Position

The importance of image simulation in interpreting experimental lattice images is well established. Normally, in carrying out the required theoretical calculations, only zero order Laue zone reflections are taken into account. In this paper we assess the conditions for which this procedure is valid and indicate circumstances in which higher order Laue zone reflections may be important. Our work is based on an analysis of the requirements for obtaining structure images i.e. images directly related to the projected potential. In the considerations to follow, the Bloch wave formulation of the dynamical theory has been used.The intensity in a lattice image can be obtained from the total wave function at the image plane is given by: where ϕg(z) is the diffracted beam amplitide given by In these equations,the z direction is perpendicular to the entrance surface, g is a reciprocal lattice vector, the Cg(i) are Fourier coefficients in the expression for a Bloch wave, b(i), X(i) is the Bloch wave excitation coefficient, ϒ(i)=k(i)-K, k(i) is a Bloch wave vector, K is the electron wave vector after correction for the mean inner potential of the crystal, T(q) and D(q) are the transfer function and damping function respectively, q is a scattering vector and the summation is over i=l,N where N is the number of beams taken into account.

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