Synthesis, spectroscopic characterization, and computed optical analysis of green fluorescent cyclohexenone derivatives

Abstract

Cyclohexenone containing chalcones core is one important class of materials, which exhibit high nonlinear optical (NLO) responses and good crystallizability. The present study reports the successful development of six new fluorescent cyclohexenone derivatives (CDs) via conventional Robinson annulation method. The molecular structures of these newly synthesized CDs were confirmed by using various analytical techniques such as 1 H NMR, 13 C NMR, FTIR, EIMS, UV-Vis spectroscopy and single crystal X-ray diffraction. The crystallographic data revealed that the spatial structure of the representative CD (4BE) belongs to monoclinic, P2 1 /c space group. The results from luminescence studies show that the CDs molecules apparently emit intense green light at room temperature in aqueous media. The relative polarity and molecular chemical stability of the CDs molecules were predicted by measuring the molecular electrostatic potential and frontier molecular orbital energy. In addition, the UV-Vis spectra, transition character and electronic structures of these CDs were computed by using quantum chemical methodology. It was interesting to note that the values of computed and experimental electronic transitions (λ max ) were in good agreement and these CDs display high hyperpolarizability (β) values. The present work will be helpful for systematical understanding of the structures and the optical properties of CDs for studying the structure-activity relationship that will suggest their potential application in photonic devices.Yellow solid, Yield 3.5 g (65.0%); m.p.: 126-127°C. 1 H NMR (CDCl 3 , 300 MHz): δ 1.07 (t, J = 7.2 Hz, 3H), 4.08 (q, J = 7.2 Hz, 2H), 3.03 (dd, J 1 = 2.2 Hz, J 2 = 18.0, 1H), 2.71-2.81 (m, 1H), 3.73 (dd J 1 = 2.9 Hz, J 2 = 6.9, 2H), 6.53 (s, 1H), 7.44 (dd J 1 = 2.8 Hz, J 2 = 6.85, 2H), 7.02 (dd J 1 = 2.5 Hz, J 2 = 6.9, 2H), 6.85 (dd J 1 = 2.1 Hz, J 2 = 6.6, 2H), 7.23 (dd J 1 = 3.0 Hz, J 2 = 6.6, 2H), 1.43 (t, J = 7.2 Hz, 3H), 4.09 (q, J = 7.1 Hz, 2H). 13 C NMR (CDCl 3 , 300 MHz): δ 193.6, 169.3, 160.3, Scheme 1. General methodology for the synthesis of cyclohexenone derivatives

Rational Design and Synthesis of Efficient Sunscreens To Boost the Solar Protection Factor

“…However, 7 is known to be chemically unstable due to the H in position 2. In addition, a fast decay to the ground state was demonstrated for 6 and 8 by NAMD (Supporting Information), with an averaged S 1 life‐time of 239±65 fs ( 8 ), on the same order as the natural sunscreen eumelanin, but much faster than commercial sunscreens components (6 ps for avobenzone in S 1 and 665 ns in T 1 , 600 fs and 2–3 ps for oxybenzone).…”

Rational Design and Synthesis of Efficient Sunscreens To Boost the Solar Protection Factor

“…On the contrary, the positive charge causes stronger,r ed-shifted absorption bands.A saconclusion, 6, 7, and 8 are the most promising cores.However, 7 is known [31,32] to be chemically unstable due to the Hinposition 2. In addition, afast decay to the ground state was demonstrated for 6 and 8 by NAMD (Supporting Information), with an averaged S 1 life-time of 239 AE 65 fs (8), on the same order as the natural sunscreen eumelanin, [27] but much faster than commercial sunscreens components (6 ps for avobenzone in S 1 [28] and 665 ns in T 1 , [29] 600 fs and 2-3 ps for oxybenzone [30] ).…”

Theoretical Investigation of para Amino-Dichloro Chalcone Isomers. Part II: A DFT Structure–Stability Study of the FMO and NLO Properties

“…Structure (III) of Figure 6 is responsible for the ICT that occurs in the (5,7)-dichloro amino chromen due to the push−pull interaction between the amine group and the π-bond system of the dichlorophenyl ring. The other chromen isomers (5,8), (5,6), (6,7), and (6,8) possess at least one resonance structure that accommodates a negative charge due to resonance on the carbon bonded to the chlorine, as shown in Figure 7. Resonance structures of (5,6), (5,8), (6,8), (6,7), and (5,8a)chromen isomers.…”

“…The other chromen isomers (5,8), (5,6), (6,7), and (6,8) possess at least one resonance structure that accommodates a negative charge due to resonance on the carbon bonded to the chlorine, as shown in Figure 7. Resonance structures of (5,6), (5,8), (6,8), (6,7), and (5,8a)chromen isomers. The calculated Mulliken charges reveal a negative charge on carbons 8, 6, 6, and 8 of the (5,8)-, (5,6)-, (6,7)-, and (6,8)chromens, respectively (Table 7).…”