Isolation and characterization of Stigmasta-7, 22-dien-3-ol (α-Spinasterol) from Entada africana stem bark crude extract

Kwaji, A.; Adamu, Haruna; Chindo, IY

doi:10.21839/jaar.2019.v4i3.294

Cited by 2 publications

(1 citation statement)

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“…The C-C single bond stretching vibrations of FTPF occurred within the range 1124-1390 cm -1 , with all having relative low PED, a basic property of saturated C-C IR stretches of alkyl groups. Unsaturated C=C stretching vibrations occurred at higher frequencies when compared to the saturated vibrations, which agrees to the theory that stronger bond exhibits vibration at higher frequencies [53]. Notable C=C stretching vibrations are 1623.58 cm -1 (PED; 75), 1617.25 cm -1 (PED; 78), 1585.58 cm -1 (PED; 62).…”

Section: C-c Vibrationssupporting

confidence: 87%

Understanding the Electronic Interactions, Vertical Excitation Analysis, and the Photovoltaic Properties of 5-(2-ethylhexyl)-1,3-di(furan-2-yl)-4H-thieno[3,4-c]pyrrole-4,6-dione

Enudi

Louis

Ogunwale

et al. 2021

Preprint

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Organic photovoltaic (OPV) are a promising new class of photovoltaic as they offer several advantageous features including large surface area to volume ratio, low cost, lightweight properties, and durability. The limitation of OPV that prevented their adoption for use in the past was their low power conversion efficiency (PCE) but that drawback has been solved by the development of the donor-acceptor-donor (D-A-D) system with high conversion efficiencies. Herein, 5-(2-ethylhexyl)-1,3-di (furan-2-yl)-4H-thieno [3,4-c]pyrrole-4,6(5H)-dione (FTPF), a donor-acceptor-donor monomer was investigated for its optoelectronic, excited state, and photovoltaic properties using a density functional theory (DFT) and time-dependent density function theory (TD-DFT) at the B3LYP/6-31+G(d,p) theoretical method. The spectral analysis (FT-IR, UV-vis, and NMR), electronic molecular properties, natural bonding orbitals (MOs and NBOs) analyses, and excitation were studied at this level in gas, hexane, DMF, and THF. The UV-Vis spectrum showed that FTPF exhibited mono-absorption in non-polar gas and hexane, but dual absorptions in polar solvents (DMF and THF) having maximum wavelength (λmax) at 351, 359, 371 and 373 nm in gas, hexane, THF, and DMF respectively, showing a major red shift as solvent became polar. The hole-electron excitation studies of the first five singlet states: S0→S1/S2/S3/S4/S5 in gas and DMF phases showed that S0→S1 is a delocalized π→π* Rydberg excitations originating from the D-A-D C=C π bonds, S0→S2 is π→π* local excitation, while S0→S3 in water occurred as an n→π* from the carbonyl and azolide groups of the acceptor unit, but n→π* charge transfer (CT) in DMF. The S0→S5 in water and S0→S4 are n→π* LE type excitations, while S0→S5 in DMF conformed to a delocalized π→π* excitation extended over the D-A-D conjugated backbone. FTPF provided efficient electron injection in all studied solvent; showing that FTPF is a sure-bet for opto-electronic application.

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Section: C-c Vibrationssupporting

confidence: 87%