RESUMEN

A novel receptor based on azo-derivatives of 1-naphthylamine (2-((E)-((4-chloro-3-(trifluoromethyl)phenyl)imino)methyl)-4-((E)-naphthalene-1-yldiazenyl)phenol(2) abbreviated CTNP was successfully designed and synthesized. Its sensing properties were studied deeply. Systematic studies of CTNP with HCO3- and AcO- anions in DMSO disclosed that there is hydrogen-bonding between CTNP and incoming anions. Significant changes in the visible region of the spectrum, as well as a drastic color change of CTNP from pale yellow to red, observed due to interaction as mentioned earlier. The stoichiometry of [CTNP: HCO3- or AcO-] complexes and association constants determined through Job's method and Benesi-Hildebrand (B-H) plot, respectively. Taking into account the analysis results, CTNP performs the selective recognition of sub-millimolar concentrations of HCO3- and AcO- efficiently. The antifungal activity of the receptor was tested against Aspergillus brasiliensis and Aspergillus niger. CTNP exhibited excellent antifungal activity against both strains. CTNP also represented antibacterial activity against Gram-positive bacteria: Staphylococcus epidermidis. It was cleared that designed receptor can be applied under physiological conditions for a long duration.

Asunto(s)

RESUMEN

A new chromogenic receptor, 4-((2,4-dichlorophenyl)diazenyl)-2-(3-hydroxypropylimino) methyl)phenol, has been designed and synthesized for quantitative and low-cost detection of various biological anions and cations. The dye was characterized by elemental analyses, infrared, UV-visible spectroscopy, and NMR spectroscopy. Upon the addition of F(-) and H2PO4(-) to the solution of chemosensor in DMSO, the dramatic naked eye detectable color changes were observed from yellow to red and orange with a limit of detection (LOD) of 1.66×10(-6)mol. L(-1) and 1.24×10(-6)mol. L(-1) at room temperature, respectively. The chemosensor showed visual changes towards cations, such as Al(3+), Cu(2+), Fe(3+), and Cr(3+), in DMSO/water (9:1). The detection limit of receptor L for the analysis of Al(3+) ion was calculated to be 3.02×10(-6)mol. L(-1). The anion recognition property of the receptor via proton transfer was monitored by UV-visible titration and (1)HNMR spectroscopy. The binding constant (Ka) and stoichiometry of the host-guest complexes formed were determined by the Benesi-Hildebrand (B-H) plot and Job's method, respectively.

RESUMEN

This paper reports results of cooperativity in lithium bonding on the strength of halogen bonding and tetrel bonding in complexes pairing CF3Cl and SiF3Cl with (LiCN)n complexes, where n varies from 1 to 5. Molecular geometries and stabilization energies of title complexes are calculated at the MP2 level with 6-311++G(d,p) basis set. Cooperative effects are found in terms of structural and energetic properties when lithium, halogen, and tetrel bonds are present in these complexes simultaneously. Our results reveal that strength of halogen and tetrel bondings are enhanced due to cooperativity of Li···N interactions in lithium bonded complexes. Good linear correlations between cooperativity parameters and electronic properties of complexes were established in the present study.