Ortho Position Of Benzene Ring Research Articles

Defects coordination triggers red-shifted photoluminescence in carbon dots and their application in ratiometric Cr(VI) sensing

Hexavalent chromium ion (Cr(VI)) is one of the most severe environmental nonbiodegradable pollutants. Considering its high biological toxicity, it is of great significance to establish a method for Cr(VI) analysis with high sensitivity and reliability. Therefore, a simple and sensitive ratiometric sensor is developed according to the coordination between Cr(VI) and carbon dots (CDs). In the presence of Cr(VI), the original CDs photoluminescence (PL) emission at 445 nm was significantly shifted to 565 nm and gradually intensified. The coordination mechanism was investigated, the results indicated that the dual-amino groups at ortho-position of benzene ring is critical for this coordination. Under the optimal condition, a good linear relationship between the concentration of Cr(VI) and the PL intensity ratio I565/I445 was obtained from 120 nM to 200 µM, with a low detection limit of 37 nM. Moreover, this method is applied into real water samples analysis with a high quality.

Short Intramolecular O···O Contact in Some o-Dialkoxybenzene Derivatives Generates Efficient Hydrogen Bonding Acceptor Area

Statistical analysis of data extracted from the Cambridge Structural Database (CSD) has been used to investigate the crystal structure properties of o-dialkoxybenzene derivatives, compounds containing two ether oxygen acceptors in ortho positions of benzene ring. It has been shown that in more than 90% of cases, the fragment has predictable geometrical characteristics where the two ether oxygens form short interatomic O···O contact (2.57 A in average), while O-substitutents take trans position, both approximately coplanar with the benzene ring. Such arrangement of oxygen acceptors produces a large and uniform area of the negative electrostatic potential suitable for multiple hydrogen bonding. The acceptor abilities of the O···O system have been investigated by the statistical CSD analysis. The ab initio estimation of the interaction energy in the dimer of o-dimethoxybenzene (DMB) and H2O, employed as a model system, is achieved via high-level electron correlation CCSD(T) calculation with the complete basi...

Antifungal Activity and Studies on Mode of Action of Novel Xanthoxyline‐Derived Chalcones

Chalcones and chalcone-like compounds, most of them new ones, prepared by base-catalyzed condensation of appropriate aldehydes and xanthoxyline, were tested for antifungal properties against a panel of yeasts, hialohyphomycetes as well as dermatophytes with the agar dilution assay. Results indicate that neither the sole presence of a "xanthoxyline-like" substitution pattern nor a 2'-OH substituent on ring A are sufficient for these compounds to have antifungal properties. The chalcone 3-(2-chlorophenyl)-1-(2'-hydroxy-4',6'-dimethoxyphenyl)prop-2-en-1-one, with a Cl atom in the ortho position of benzene ring B showed the best antifungal activity against standardized strains of Trichophyton rubrum (MIC = 12.5 microg/mL) and inhibited all of the ten clinical isolates of T. rubrum tested (MIC at which 50 % [MIC(50)] and 90 % [MIC(90)] of the isolates were inhibited = 12.5 and 25 microg/mL). Regarding its mode of action, the Neurospora crassa assay showed a blotchy appearance in the inhibition halo produced by this chalcone, strongly suggesting that it could act by inhibiting the fungal cell wall. This chalcone seems to be an hyphal malformation inducer, since a clear curling of the hypha was observed in this hazy zone at a magnification of x 400. This work strongly contributes to the knowledge of the antifungal properties of hydroxy-chalcones.

Functionalized Alkyl and Aryl Diselenides as Antimicrobial and Antiviral Agents: Synthesis and Properties.

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Functionalized alkyl and aryl diselenides as antimicrobial and antiviral agents: synthesis and properties

The different dialkyl and diaryl diselenides with carbamoyl and sulfamoyl moieties 2, 3, 5 and other substituents in the ortho position of benzene ring 4, 7, 8 as well as derivatives of 1,2,4-benzoselenadiazine ( 6) were designed as antiviral and antimicrobial agents and synthesized. Some of them, particularly 8a and 8b, were found in the antiviral assay in vitro to be strong inhibitors of cytopathic activity encephalomyocarditis virus (EMCV). The compound 4a and 8a were found to have a broad spectrum of acivity against bacteria, yeasts and pathogenic fungi in vitro.

(4,5-Dimethoxy-2-nitrophenyl)-(5-methylfuran-2-yl)methanone

To continue our investigation into the chemistry of furan derivatives [1, 2], we have synthesized furylphenylketone bearing nitro-group in the ortho-position of benzene ring.[...]