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.

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.

Synthesis, photophysical and nonlinear optical properties of a series of ball-type phthalocyanines in solution and thin films

2017 ◽  
Vol 41 (5) ◽  
pp. 2020-2028 ◽  
Author(s):  
Njemuwa Nwaji ◽  
John Mack ◽  
Jonathan Britton ◽  
Tebello Nyokong
Keyword(s):  
Thin Films ◽  
Density Functional Theory ◽  
Optical Properties ◽  
Density Functional ◽  
Nonlinear Optical ◽  
Time Dependent ◽  
Optical Behaviour ◽  
Functional Theory ◽  
Td Dft ◽  
Dependent Density

Ball-type phthalocyanines containing heavy central metals show enhanced nonlinear optical behaviour in solution or when embedded in polymer thin films. Time dependent density functional theory (TD-DFT) calculations were used to explain the spectra.

scholarly journals Spectroscopic (FT-IR, FT-Raman, UV, 1H and 13C NMR) insights, electronic profiling and DFT computations on ({(E)-[3-(1H-imidazol-1-yl)-1-phenylpropylidene] amino}oxy)(4-nitrophenyl)methanone, an imidazole-bearing anti-Candida agent

2018 ◽  
Vol 16 (1) ◽  
pp. 50-63 ◽  
Author(s):  
Lamya H. Al-Wahaibi ◽  
Munusamy Govindarajan ◽  
Ali A. El-Emam ◽  
Mohamed I. Attia
Keyword(s):  
Density Functional Theory ◽  
Title Compound ◽  
Density Functional ◽  
Orbital Method ◽  
Functional Theory ◽  
Nmr Characterization ◽  
Td Dft ◽  
Ft Ir ◽  
C Nmr ◽  
Ft Raman

AbstractThe anti-Candida agent, ({(E)-[3-(1H-imidazol-1-yl)-1-phenylpropylidene]amnio}oxy(4-nitropheny) methanone (IPAONM), was subjected to comprehensive spectroscopic (FT-IR, FT-Raman, UV–Vis 1H and 13C NMR) characterization as well as Hartree Fock and density functional theory computation studies. The selected optimized geometric bond lengths and bond angles of the IPAONM molecule were compared with the experimental values. The calculated wavenumbers have been scaled and compared with the experimental spectra. Mulliken charges and natural bond orbital analysis of the title molecule were calculated and interpreted. The energy and oscillator strengths of the IPAONM molecule were calculated by time-dependent density functional theory (TD-DFT). In addition, frontier molecular orbitals and molecular electrostatic potential diagram of the title compound were computed and analyzed. A study on the electronic properties, such as HOMO, HOMO-1, LUMO and LUMO+1 energies was carried out using TD-DFT approach. The 1H and 13C NMR chemical shift values of the title compound were calculated by the gauge independent atomic orbital method and compared with the experimental results.

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.

Computational approaches to the determination of active site structures and reaction mechanisms in heterogeneous catalysts

2005 ◽  
Vol 363 (1829) ◽  
pp. 913-936 ◽  
Author(s):  
C.R.A Catlow ◽  
S.A French ◽  
A.A Sokol ◽  
J.M Thomas
Keyword(s):  
Active Site ◽  
Reaction Mechanisms ◽  
Density Functional ◽  
Heterogeneous Catalysts ◽  
Bond Activation ◽  
Molecular Cluster ◽  
Chemical Methods ◽  
Functional Theory ◽  
Quantum Chemical Methods

We apply quantum chemical methods to the study of active site structures and reaction mechanisms in mesoporous silica and metal oxide catalysts. Our approach is based on the use of both molecular cluster and embedded cluster (QM/MM) techniques, where the active site and molecular complex are described using density functional theory (DFT) and the embedding matrix simulated by shell model potentials. We consider three case studies: alkene epoxidation over the microporous TS-1 catalyst; methanol synthesis on ZnO and Cu/ZnO and C–H bond activation over Li-doped MgO.

scholarly journals Synthesis, optical and electrochemical study of bipolar heterocyclic systems, including 1,2,4-oxadiazole moiety

2016 ◽  
Vol 4 (1) ◽  
Author(s):  
D. G. Selivanova ◽  
O. A. Mayorova ◽  
A. A. Gorbunov ◽  
A. N. Vasyanin ◽  
M. V. Dmitriev ◽  
...  
Keyword(s):  
Excited States ◽  
Density Functional ◽  
Time Dependent ◽  
Electrochemical Studies ◽  
Absorption Data ◽  
Functional Theory ◽  
Conjugation Chain ◽  
Td Dft ◽  
Triplet Excited States ◽  
New Compounds

AbstractTwo new 3,5-dihetarylsubstituted 1,2,4- oxadiazoles 8 a,b, including N-alkyl substituted carbazole and thiophene moieties, were synthesized as potential components of materials for organic electronics devices. Optical and electrochemical properties of all new compounds were investigated. On the basis of the experimental UV absorption data, the values of bandgap energies equal to 3.44 eV (8a) and 3.05 eV (8b) were determined. The values of their ionization potentials, HOMO levels (−5.62 eV for 8a, −5.46 eV – for 8b), as well as their electron affinity levels, LUMO levels (−2.2 eV for 8a, −2.4 eV – for 8b), were calculated from the results of electrochemical studies. The energy of the triplet excited states of 8 a,b was defined with the help of time-dependent density functional theory (TD-DFT), comprising 2.68 eV (8a) and 2.32 eV (8b), where the greatest value of this parameter was for the compound with a shorter conjugation chain.

scholarly journals New Octadecanoid Enantiomers from the Whole Plants of Plantago depressa

Molecules ◽  
2018 ◽  
Vol 23 (7) ◽  
pp. 1723 ◽  
Author(s):  
Xiu-Qing Song ◽  
Kongkai Zhu ◽  
Jin-Hai Yu ◽  
Qianqian Zhang ◽  
Yuying Zhang ◽  
...  
Keyword(s):  
Density Functional ◽  
Ethanolic Extract ◽  
Raw 264.7 Cells ◽  
No Production ◽  
Functional Theory ◽  
Td Dft ◽  
Whole Plants ◽  
New Compounds ◽  
First Time

In this study, 19 octadecanoid derivatives—four pairs of enantiomers (1–8), two racemic/scalemic mixtures (9–10), and nine biosynthetically related analogues—were obtained from the ethanolic extract of a Chinese medicinal plant, Plantago depressa Willd. Their structures were elucidated on the basis of detailed spectroscopic analyses, with the absolute configurations of the new compounds assigned by time-dependent density functional theory (TD-DFT)-based electronic circular dichroism (ECD) calculations. Six of them (1, 3–6, and 9) were reported for the first time, while 2, 7, and 8 have been previously described as derivatives and are currently obtained as natural products. Our bioassays have established that selective compounds show in vitro anti-inflammatory activity by inhibiting lipopolysaccharide-induced nitric oxide (NO) production in mouse macrophage RAW 264.7 cells.

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