Dataset Information

Photocatalytic Reduction of Fluorescent Dyes in Sunlight by Newly Synthesized Spiroindenoquinoxaline Pyrrolizidines.

ABSTRACT: Spiroindenoquinoxaline pyrrolizidines (SIQPs)-7-nitro-2'-phenyl-5',6',7',7a'-tetrahydrospiro[indeno[1,2-b]quinoxaline-11,3'-pyrrolizine]-1',1'(2'H)-dicarbonitrile (SIQP I), 2'-(4-cyanophenyl)-7-nitro-5',6',7',7a'-tetrahydrospiro[indeno[1,2-b]quinoxaline-11,3'-pyrrolizine]-1',1'(2'H)-dicarbonitrile (SIQP II), and 2'-(4-methoxyphenyl)-7-nitro-5',6',7',7a'-tetrahydrospiro[indeno[1,2-b]quinoxaline-11,3'-pyrrolizine]-1',1'(2'H)-dicarbonitrile (SIQP III)-have been synthesized through a one-pot cascade Knoevenagel condensation reaction in acetonitrile (ACN) with 91, 98, and 87% yields, respectively. Structures are characterized by ¹H NMR and ¹³C NMR spectroscopy, nuclear Overhauser enhancement spectroscopy (NOESY), Fourier transform infrared (FT-IR) and UV-vis spectroscopy, thermogravimetric analysis (TGA), high-resolution mass spectroscopy (HRTEM), fluorescence and Raman spectroscopy, and energy-dispersive analysis by X-ray (EDX) spectroscopy. SIQPs in ACN photocatalyzed methylene blue (MB) but not phenolphthalein (HIn). SIQPs distinguished the quaternary atoms and dipoles of the fluorescent dye (MB) contrary to the quinonoid HIn structure. In sunlight, SIQPs without electricity input acted as a photonic sensor to detect fluorescent dyes in waste effluents of textile, paper, dyes, and other industries. Activation energy (E _a), enthalpy (ΔH), entropy (ΔS), and Gibbs free energy (ΔG) calculated from UV-vis absorption spectra show photocatalytic reduction (PCR) activities in the order SIQP II > III > I. The N-atom of pyrrolizidine and -NO₂ of nitro-indenoquinoxaline (NIQ) induced the highest occupied molecular orbital (HOMO) to the lowest unoccupied molecular orbital (LUMO) electrodynamics to enable the SIQPs to catalyze biochemical activities.

SUBMITTER: Kumari R

PROVIDER: S-EPMC7495801 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature

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Photocatalytic Reduction of Fluorescent Dyes in Sunlight by Newly Synthesized Spiroindenoquinoxaline Pyrrolizidines.

Kumari Renu R Singh Man M

ACS omega 20200901 36

Spiroindenoquinoxaline pyrrolizidines (SIQPs)-7-nitro-2'-phenyl-5',6',7',7a'-tetrahydrospiro[indeno[1,2-b]quinoxaline-11,3'-pyrrolizine]-1',1'(2'H)-dicarbonitrile (SIQP I), 2'-(4-cyanophenyl)-7-nitro-5',6',7',7a'-tetrahydrospiro[indeno[1,2-b]quinoxaline-11,3'-pyrrolizine]-1',1'(2'H)-dicarbonitrile (SIQP II), and 2'-(4-methoxyphenyl)-7-nitro-5',6',7',7a'-tetrahydrospiro[indeno[1,2-b]quinoxaline-11,3'-pyrrolizine]-1',1'(2'H)-dicarbonitrile (SIQP III)-have ...[more]

PMID: 32954171

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Project description:In this work, lanthanide sulphide nanorods (LSNRs) of neodymium (Nd2S3), europium (Eu2S3), erbium (Er2S3), and ytterbium (Yb2S3) were prepared with a LnCl3·6H2O salt, sodium metal, and H2S gas through a crash reaction methodology (CRM) at NTP. The LSNRs were doped with gadolinium ions (Gd3+) and coated with graphene oxide (GO) to prepare bimetallic LSNRs (B@LSNRs) and GO templates (B@LGTs), respectively. LSNRs, B@LSNRs, and B@LGTs were characterised using XRD, FT-IR spectroscopy, BET analysis, UV/vis spectroscopy, HR-TEM, SEM, TGA/DTG, XPS, Raman spectroscopy, and elemental analysis. The B@LGTs as interstitial photocatalysts photocatalytically reduced the Coomassie brilliant blue red (BBR) dye, transition metal ions (TMIs), and quinonoid phenolphthalein (QHIn) in aqueous solutions under visible light. Experimental parameters including pollutant concentrations, B@LGT dosages, physicochemical properties (PCPs), and pH were optimized for achieving monodispersion and maximum PCR. The PCPs like density, viscosity, sound velocity, surface tension, friccohesity, and isentropic compressibility have predicted the spontaneity and sustainability at 288.15, 298.15, and 310.15 K with photocatalysing medium. B@Nd2S3:GO, B@Eu2S3:GO, B@Er2S3:GO, and B@Yb2S3:GO with 2.23, 2.28, 2.38, and 1.88 eV bandgaps (E g) and -670.14, -829.18, -767.39, and -925.57 J mol-1 activation energies (E a) having -0.9869, 0.8843, -1.4011, and -1.2102 J mol-1 entropies (ΔS) photocatalytically reduced a dye with 96.35, 96.67, 97.60, and 99.17% quantum yields (Φ), respectively. The above-mentioned data indicated that the B@LGTs are robust photocatalysts that photocatalytically reduce BBR in 48 and 30 times shorter duration than LSNRs and B@LSNRs, respectively. It was found that 0.01 g% B@LGTs photocatalytically reduced 40 ppm BBR and 20 ppm CrCl3, NiCl2, CuCl2, and QHIn in 30, 20, 40, 35, and 15 min, respectively. Kinetic rate constants of 3.25 × 10-2, 3.21 × 10-2, 3.18 × 10-2 and 3.15 × 10-2 min-1 for BBR were in the order of B@Nd2S3:GO > B@Er2S3:GO > B@Eu2S3:GO > B@Yb2S3:GO with 4f3e, 4f11e, 4f6e, and 4f13e electrons, respectively. This indicated first-order reaction similar to QHIn and TMIs. Furthermore, the B@LGTs exhibited favourable stabilities, with 58.1-68.05% PCR efficiencies after 10 cycles of reduction experiments.

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Dataset Information

Photocatalytic Reduction of Fluorescent Dyes in Sunlight by Newly Synthesized Spiroindenoquinoxaline Pyrrolizidines.

Publications

Photocatalytic Reduction of Fluorescent Dyes in Sunlight by Newly Synthesized Spiroindenoquinoxaline Pyrrolizidines.

Similar Datasets

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