title: 1,3-Di-amidoquinoline conjugate of calix[4]arene (L) as a ratiometric and colorimetric sensor for Zn2+: spectroscopy, microscopy and computational studies.
abstract: Carboxamidoquinoline appended calix[4]arene-1,3-di-conjugate (L) has been synthesized and characterized and its single crystal XRD structure has been established. L has been shown to act as selective ratiometric turn-on fluorescence sensor for Zn(2+) up to a lowest concentration of 183 ± 18 ppb (2.82 μM) with a nine-fold enhancement by exhibiting blue-green emission. The coordination features of the species of recognition have been computationally evaluated by DFT methods and found to have distorted tetrahedral Zn(2+) center in an N(4) core. The spherical nano-structural features observed for L in TEM are being transformed into the Koosh nano-flower like structure when complexed with Zn(2+) and hence these two can be easily differentiated. Even the features observed in AFM can distinctly differentiate L from its Zn(2+) complex.
authors.affiliation: Bioinorganic Laboratory, Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, 400 076, India.
authors.forename: V V Sreenivasu
authors.initials: VV
authors.lastname: Mummidivarapu
authors.forename: Khatija
authors.initials: K
authors.lastname: Tabbasum
authors.forename: Jugun Prakash
authors.initials: JP
authors.lastname: Chinta
authors.forename: Chebrolu P
authors.initials: CP
authors.lastname: Rao
mesh_terms: D000577:Amides / Q000737:chemistry; D047250:Calixarenes / Q000737:chemistry*; D003124:Colorimetry / Q000379:methods*; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D049329:Nanostructures / Q000737:chemistry / Q000648:ultrastructure; D010636:Phenols / Q000737:chemistry*; D011804:Quinolines / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000379:methods; D015032:Zinc / Q000032:analysis*
chemical_list: D000577:Amides; D010636:Phenols; D011804:Quinolines; C121325:calix(4)arene; D047250:Calixarenes; D015032:Zinc