2.1.1 General procedure for the synthesis of MSPPP Chalcone
A novel compound 1-(4-methylsulfonyl phenyl)-3-(4-N, N dimethyl (amino phenyl)-2 propen-1-one (MSPPP) was synthesized using a simple reaction in a vessel containing 4- dimethylaminobenzaldehyde (0.01 mol) and 4-methyl acetophenone (0.01 Mole) in basic condition of Sodium Hydroxide (1.0 gm) and ethanol (50 ml) as a solvent. The vessel was left overnight at room temperature (270C) and then the yield was recrystallized from ethanol. The yellow precipitate formed was washed with water and dried in air after the reaction mixture was stirred for 8 h. The crude product was used for crystal growth. Single crystals of MSPPP were grown from acetone by slow evaporation technique at room temperature. A saturated solution of MSPPP was obtained by dissolving the synthesized material in acetone with continuous stirring (8 h) at room temperature. This saturated solution was filtered using Whatman filter paper and the solution was transferred to a beaker and the solvent was allowed to evaporate slowly. After 6 days, transparent thin plate-like crystals were successfully harvested. The crystal was washed with distilled water, and it had been left to dry. Image of the MPMPP crystal was recorded on Euromex optical microscope equipped with an optical polarizer and CMEX digital camera. The crystal was washed with distilled water and left to dry (yield94%) and characterized using H1NMR, FTIR, and UV–Vis’s spectroscopy, as previously described Attia, M. F. et al. [15]. The molecular structures of MSPPP and DAPPP are presented in Scheme 1.
The product was characterized by by H1 NMR and UV – Vis spectroscopy, 1H NMR: δ 2.86 (6H, s), 3.07 (3H, s), 6.47 (1H, d, J = 15.6 Hz), 6.84 (2H, ddd, J = 8.2, 1.2, 0.4 Hz), 7.47–7.58 (3H, 7.51 (d, J = 15.6 Hz), 7.55 (ddd, J = 8.2, 1.5, 0.5 Hz)), 7.81 (2H, ddd, J = 7.9, 1.9, 0.5 Hz), 8.01 (2H, ddd, J = 7.9, 1.5, 0.5 Hz) ppm (Fig. 1). 13C NMR: δ 40.3 (2C, s), 44.3 (1C, s), 112.0 (2C, s), 121.2 (1C, s), 128.4 (2C, s), 128.6 (2C, s), 128.9 (2C, s), 130.3 (1C, s), 135.5 (1C, s), 137.4 (1C, s), 144.1 (1C, s), 150.9 (1C, s), 188.9 (1C, s) ppm λmax (methanol 419 nm). (Fig. 1a)
The NMR spectrum shows two closely spaced singlets at δ = 3.06 and δ = 2.86 PPM which corresponds to two − OCH 3 groups. Two chalcone protons appeared as two doublets at δ = 7.71 and δ = 7.05 PPM. The aromatic protons of p - methoxyphenyl moiety also appeared as two doublets at δ = 8.01 and δ = 7.75 PPM. (Fig. 1b)