SPECTROSCOPIC AND QUANTUM-CHEMICAL INVESTIGATION OF TESTOSTERONE PROPIONATE, A COMMONLY MISUSED ANABOLIC STEROID

2021 ◽  
Author(s):  
Nikola Ristivojević ◽  
◽  
Dušan Dimić ◽  
Marko Đošić ◽  
Stefan Mišić ◽  
...  
Keyword(s):  
Quantum Chemical ◽  
Density Functional ◽  
Testosterone Propionate ◽  
Anabolic Steroids ◽  
Chemical Methods ◽  
Dft Methods ◽  
Functional Theory ◽  
Quantum Chemical Methods ◽  
Td Dft ◽  
Ir And Raman

Anabolic steroids are a group of commonly counterfeit substances used by individuals who want to gain weight and muscles. Testosterone propionate (TP), an ester analog of testosterone, belongs to this group and its spectroscopic analysis is important especially when it is improperly labeled and misused. In this contribution quantum chemical methods, at the B3LYP/6- 311++G(d,p) level of theory, were applied for the prediction of the vibrational (IR and Raman) and UV-VIS spectra of TP. The applicability of the chosen level of theory was proven based on the comparison between experimental and theoretical bond lengths and angles. The most prominent bands in the IR and Raman spectra were assigned and correlated with the calculated ones. The electronic spectra were also analyzed and the assignments were made based on the Time-Dependent Density Functional Theory (TD-DFT) calculations. The orbitals included in the most intense transitions were visualized and possible solvent effects were discussed. The presented results proved the applicability of the DFT methods for the prediction of spectra that could lead to the counterfeit substances determination.

Halogen bonded supramolecular capsules: a challenging test case for quantum chemical methods

2016 ◽  
Vol 52 (64) ◽  
pp. 9893-9896 ◽  
Author(s):  
Rebecca Sure ◽  
Stefan Grimme
Keyword(s):  
Density Functional Theory ◽  
Quantum Chemical ◽  
Density Functional ◽  
State Of The Art ◽  
Test Case ◽  
Binding Affinities ◽  
Chemical Methods ◽  
Functional Theory ◽  
Quantum Chemical Methods

By state-of-the-art dispersion corrected density functional theory, the complexation properties of a recently synthesized halogen-bonded capsule with about 400 atoms are investigated and predictions for improved binding affinities are made.

Spin-state energetics of metallocenes: How do best wave function and density functional theory results compare with the experimental data?

2021 ◽  
Vol 23 (1) ◽  
pp. 151-172
Author(s):  
Gabriela Drabik ◽  
Janusz Szklarzewicz ◽  
Mariusz Radoń
Keyword(s):  
Experimental Data ◽  
Density Functional Theory ◽  
Wave Function ◽  
Spin State ◽  
Quantum Chemical ◽  
Density Functional ◽  
Chemical Methods ◽  
Functional Theory ◽  
Quantum Chemical Methods

Benchmarking quantum-chemical methods against experiment-derived spin-state energetics of metallocenes.

Quantum chemical treatments of metal clusters

2010 ◽  
Vol 368 (1915) ◽  
pp. 1245-1263 ◽  
Author(s):  
Florian Weigend ◽  
Reinhart Ahlrichs
Keyword(s):  
Quantum Chemical ◽  
Density Functional ◽  
Metal Clusters ◽  
Potential Surface ◽  
A Priori ◽  
Chemical Methods ◽  
Functional Theory ◽  
Chemical Treatments ◽  
Quantum Chemical Methods ◽  
Different Types

This work focuses on finding and rationalizing the building principles of clusters with approximately 300 atoms of different types of metals: main group elements (Al, Sn), alkaline earth metals (Mg), transition metals (Pd) and clusters consisting of two different elements (Ir and Pt). Two tools are inevitable for this purpose: (i) quantum chemical methods that are able to treat a given cluster with both sufficient accuracy and efficiency and (ii) algorithms that are able to systematically scan the (3 n −6)-dimensional potential surface of an n -atomic cluster for promising isomers. Currently, the only quantum chemical method that can be applied to metal clusters is density functional theory (DFT). Other methods either do not account for the multi-reference character of metal clusters or are too expensive and thus can be applied only to clusters of very few atoms, which usually is not sufficient for studying the building principles. The accuracy of DFT is not known a priori , but extrapolations to bulk values from calculated series of data show satisfying agreement with experimental data. For scans of the potential surface, simulated annealing techniques or genetic algorithms were used for the smaller clusters (approx. 20–30 atoms), and for the larger clusters considerations were restricted to selected packings and shapes. For the mixed-metallic clusters, perturbation theory turned out to be efficient and successful for finding the most promising distributions of the two atom types at the different sites.

STRUCTURAL, ELECTRONIC AND OPTICAL PROPERTIES OF THIOPHENE AND THIENOTHIOPHENE CONTAINING DIKETO-PYRROLO-PYRROLES (DPPs) IN POLAR APROTIC SOLVENTS

2013 ◽  
Vol 01 (01) ◽  
pp. 1250003 ◽  
Author(s):  
HONGJUN LIU ◽  
ERIC ASSEN B. KANTCHEV ◽  
HUEI SHUAN TAN ◽  
TYLER B. NORSTEN
Keyword(s):  
Optical Properties ◽  
Density Functional ◽  
Chemical Methods ◽  
Functional Theory ◽  
Molecular Conformations ◽  
Quantum Chemical Methods ◽  
Td Dft ◽  
Ct Complex ◽  
New Compounds ◽  
C Nmr

Thiophene (T) and thienothiophene (TT) containing 2,5-dihydro-pyrrolo[3,4-c]pyrrole-1,4-dione (DPP) compounds were prepared according to the succinic ester route from the corresponding heterocyclic nitrile precursors. As is typical of most DPP pigments, the new compounds showed high thermal stability and could be obtained in pure form as determined by elemental analysis. The bulk properties and molecular structure of the compounds were further characterized by thin film, powder XRD and solid state CP-MAS 13 C NMR. Density functional theory (DFT) and time-dependent (TD) DFT were employed to study the geometric and electronic structures of these molecules in the ground state. The optical properties were investigated by UV-Vis absorption and fluorescence spectroscopies in dimethylsulfoxide (DMSO) and N,N-dimethylacetamide (DMA), which revealed that the absorption maximum of the thiophene diketo-pyrrolo-pyrroles (TDPP) and thienothiophene diketo-pyrrolo-pyrroles (TTDPP) in solution were red shifted up to 25 nm and 60 nm, respectively, relative to Pigment Red 255 (PhDPP), while a new absorption band appeared at longer wavelengths in N-methyl pyrolidone (NMP) and N,N′-dimethylpropylene urea (DMPU) which is ascribed to solvent induced charge transfer (CT) complex. The molecular conformations and absorption spectra of TDPP and TTDPP were characterized by quantum chemical methods in order to better understand the observed behavior.

Enhancing the blue phosphorescence of iridium complexes with a dicyclometalated phosphite ligand via aza-substitution: a density functional theory investigation

2014 ◽  
Vol 2 (39) ◽  
pp. 8364-8372 ◽  
Author(s):  
Gahungu Godefroid ◽  
Liu Yuqi ◽  
Si Yanling ◽  
Su Juanjuan ◽  
Qu Xiaochun ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Quantum Chemical ◽  
Density Functional ◽  
Photophysical Properties ◽  
Iridium Complexes ◽  
Chemical Methods ◽  
Functional Theory ◽  
Quantum Chemical Methods ◽  
Blue Phosphorescent

The influence of azasubstitution on electronic and photophysical properties of iridium complexes of blue phosphorescent dicyclometalated phosphite has been explored using quantum chemical methods.

scholarly journals Sulfate radical oxidation of aromatic contaminants: a detailed assessment of density functional theory and high-level quantum chemical methods

2017 ◽  
Vol 19 (3) ◽  
pp. 395-404 ◽  
Author(s):  
Sangavi Pari ◽  
Inger A. Wang ◽  
Haizhou Liu ◽  
Bryan M. Wong
Keyword(s):  
Density Functional Theory ◽  
Quantum Chemical ◽  
Density Functional ◽  
Sulfate Radical ◽  
Chemical Methods ◽  
Functional Theory ◽  
Radical Oxidation ◽  
Quantum Chemical Methods ◽  
Detailed Assessment ◽  
High Level

DFT and high-level quantum methods are utilized to explore sulfate radical-driven oxidation.

Comparative DFT study for molecular geometries and spectra of methyl pheophorbides-a: test of M06-2X and two other functionals

2010 ◽  
Vol 14 (07) ◽  
pp. 592-604 ◽  
Author(s):  
Do Sung Huh ◽  
Sang Joon Choe
Keyword(s):  
Density Functional Theory ◽  
Standard Deviation ◽  
Density Functional ◽  
Visible Spectrum ◽  
Mean Value ◽  
Time Dependent ◽  
Dft Methods ◽  
Functional Theory ◽  
Td Dft ◽  
The Mean

The recent interest in the application of density functional theory (DFT) has prompted us to test several functions in molecular geometries of methyl pheophorbides-a (MPa), an important starting material in photodynamic therapy (PDT). In this study, we report on tests for three popular DFT methods: M06-2X, B3LYP, and LSDA. Based on the standard deviation and the mean value, and by using the difference between optimized calculated value and experimental value in geometries, we drew the following conclusions: M06-2X/6-311+G(d,p) attained the smallest standard deviation of difference among the tested DFT methods in terms of bond length, whereas the standard deviation of bond angle in LSDA/6-311+G(d,p) was the smallest. In terms of absolute value, the mean value of LSDA/6-311+G(d,p) calculation was larger than that of M06-2X/6-311+G(d,p). We found that M06-2X/6-311+G(d,p) gave the best performance for MPa in the molecular geometries. The UV-visible spectrum was calculated with time-dependent density-functional theory (TD-DFT). Time-dependent M06-2X/6-311+G(d,p) gave the best performance for MPa in CH2Cl2 solution. In general, TD-DFT calculations in CH2Cl2 solution were more red-shifted compared with those in the solid state.

scholarly journals How accurate are approximate quantum chemical methods at modelling solute–solvent interactions in solvated clusters?

2020 ◽  
Vol 22 (7) ◽  
pp. 3855-3866 ◽  
Author(s):  
Junbo Chen ◽  
Bun Chan ◽  
Yihan Shao ◽  
Junming Ho
Keyword(s):  
Ab Initio ◽  
Quantum Chemical ◽  
Interaction Energies ◽  
Chemical Methods ◽  
Dft Methods ◽  
Solvent Interactions ◽  
Quantum Chemical Methods ◽  
Composite Methods ◽  
Wide Range

In this paper, the performance of ab initio composite methods, and a wide range of DFT methods is assessed for the calculation of interaction energies of thermal clusters of a solute in water.

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