scholarly journals Spectral and quantum chemical analysis of ethyl 4-[3-(adamantan-1-yl)-4-phenyl-5-sulfanylidene-4,5-dihydro-1H-1,2,4-triazole-1-yl]methylpiperazine-1-carboxylate

2019 ◽  
Vol 18 (06) ◽  
pp. 1950029
Author(s):  
Hanan A. Al-Ghulikah ◽  
Darya Meniailava ◽  
Ulada Vysotskaya ◽  
Anna Matsukovich ◽  
Ali A. El-Emam ◽  
...  
Keyword(s):  
Raman Spectra ◽  
Quantum Chemical ◽  
Intramolecular Charge Transfer ◽  
Population Analysis ◽  
Quantum Chemical Analysis ◽  
Experimental Ir ◽  
Chemical Modeling ◽  
Tddft Calculations ◽  
The Fourier Transform ◽  
Ir And Raman

The Fourier transform infrared and Raman spectra of the adamantane-based compound ethyl 4-[3-(adamantan-1-yl)-4-phenyl-5-sulfanylidene-4,5-dihydro-1H-1,2,4-triazol-1-yl]methylpiperazine-1-carboxylate were recorded in the ranges of 3200–650[Formula: see text]cm[Formula: see text] and 3200–150[Formula: see text]cm[Formula: see text], respectively. The UV/Vis spectrum of solution of the title compound in ethanol was measured in the range of 450–200[Formula: see text]nm. The DFT calculations at the B3LYP/cc-pVDZ and B3LYP/cc-pVTZ levels of the theory were performed to obtain the equilibrium geometric structure and to predict vibrational IR and Raman spectra of the title molecule. The TDDFT calculations at the CAM-B3LYP/cc-pVTZ level of the theory, as well as MRPT calculations at the CASSCF(4,5)/XMCQDPT2 level of the theory were carried out to reproduce the electronic absorption spectrum. The experimental IR, Raman and UV/Vis spectra were interpreted on the basis of results of quantum chemical modeling. Based on Mulliken and Löwdin atomic population analysis, it was established that the compound under study exhibits features of an intramolecular charge transfer.

scholarly journals STUDY OF STRUCTURAL ORGANIZATION OF SYSTEMS ON BASIS OF p-n-PROPYLOXICINNAMIC ACID AND NONMESOGENES OF Ph–X–Ph TYPE

2019 ◽  
Vol 62 (4) ◽  
pp. 87-94
Author(s):  
Ivan S. Lebedev ◽  
Ivan A. Filippov ◽  
Kseniya E. Bubnova ◽  
Nina I. Giricheva ◽  
Mikhail S. Fedorov ◽  
...  
Keyword(s):  
Quantum Chemical ◽  
Structural Organization ◽  
Intermolecular Interaction Energy ◽  
Phenyl Benzoate ◽  
Experimental Ir ◽  
Structural Units ◽  
Similar System ◽  
Chemical Modeling ◽  
Low Probability ◽  
Complexation Reactions

The variants of structural organization in the systems “mesogen – nonmesogen” are considered. The systems contain p-n-propyloxycinnamic acid (A), as a mesogenic component, and nonmesogenic Ph–X–Ph compounds: phenyl benzoate (B, where X = –COO–), azobenzene (C, where X = –N=N–) and N-benzylideneaniline (D, where X = –CH=N–). Quantum-chemical modeling of possible structural units in such systems has been performed. It was shown that all assumed A∙∙∙X(Ph)2 H-complexes do not have electronic and geometric anisotropy and have a lower intermolecular interaction energy than the cyclic dimer of acid A∙∙∙A. The calculated values of the Gibbs free energy of complexation reactions also indicate a low probability of the formation of A∙∙∙X(Ph)2 type H-complexes. It is noted that the “length” of the A∙∙∙A dimer is comparable with the doubled “length” of Ph–X–Ph molecules, which, like the acid dimer, have a rod-like structure favorable for the formation of nematic and smectic LC phases. Based on the analysis of the quantum chemical calculations, it was assumed that Ph–X–Ph can be embedded between acid cyclic dimers A∙∙∙A and can facilitate reduce intermolecular interactions in the system, which reduces the temperature of Cr–LC transitions. The proposed structural organization of systems A: Ph–X–Ph is confirmed by an experimental IR spectrum for a similar system, in which the bands corresponding to the vibrational frequencies of the acid dimer and to individual molecules of alkyloxy substituted phenyl benzoate B are recorded.

Structural, Vibrational and UV/Vis Studies of Adamantane-Containing Triazole Thiones by Spectral, DFT and Multi-reference ab initio Methods

2020 ◽  
Vol 234 (1) ◽  
pp. 85-106 ◽  
Author(s):  
Maksim Shundalau ◽  
Yuliya L. Mindarava ◽  
Anna S. Matsukovich ◽  
Sergey V. Gaponenko ◽  
Ali A. El-Emam ◽  
...  
Keyword(s):  
Raman Spectra ◽  
Vibrational Spectra ◽  
Density Functional ◽  
Geometry Optimization ◽  
Density Functional Theory Calculations ◽  
Equilibrium Geometry ◽  
Full Geometry Optimization ◽  
Analgesic Activities ◽  
The Fourier Transform ◽  
Ir And Raman

AbstractThe Fourier transform infrared and Raman spectra of two adamantane-containing triazole thiones, namely 3-(adamantan-1-yl)-1-[(4-benzylpiperazin-1-yl)methyl]-4-phenyl-1H-1,2,4-triazole-5(4H)-thione and 3-(adamantan-1-yl)-4-phenyl-1-[(4-phenylpiperazin-1-yl)methyl]-1H-1,2,4-triazole-5(4H)-thione, were examined in the ranges of 3200–650 cm−1 and 3200–150 cm−1, respectively. The density functional theory calculations were performed for the geometric structures and vibrational spectra for the title molecules. The accurate equilibrium geometry structures of the molecules were determined on the basis of full geometry optimization at the B3LYP/cc-pVDZ level of the theory. The IR and Raman vibrational spectra were calculated and compared with the experimental ones. The experimental vibrational FT-IR and Raman spectra were interpreted. Based on the structure of the molecules the biological activity indices were predicted. It is established that compounds under consideration are very likely to exhibit the analgesic activities. The UV/Vis spectra of solution of the compounds in ethanol were measured in the range of 450–200 nm. The UV/Vis spectra simulations at the Time-Dependent DFT and Multi-Reference Perturbation Theory levels of theory demonstrate unsuitability of the TDDFT for description of the experimental spectra of the title molecules. It is highly probable that this is a consequence of the intramolecular charge transfer. In contrast, the MRPT results are in a good agreement with the experimental spectra.

Sign in / Sign up

Export Citation Format

Share Document