1381755-57-2Relevant articles and documents
Selective recognition of Zn2+ by a triazole linked thiophene-methylimine based derivative of calix[6]arene and the secondary sensing of biothiols by the corresponding zinc complex
Nehra, Anita,Hinge, Vijay Kumar,Nag, Rahul,Rao, Chebrolu Pulla
, p. 1541 - 1549 (2020/06/27)
A 1,3,5-tris-triazole linked thiophene-methylimino appended calix[6]arene conjugate, L has been shown to bind to Zn2+ selectively in ethanol among the metal ions studied which include, alkali and alkaline earth ions, transition metal ions and lanthanides by fluorescence, absorption and ESI-MS. The conjugate, L exhibited ~25 fold increase in its fluorescence intensity at λem = 450 nm in presence of Zn2+ upon exciting at 330 nm with a limit of detection of 25±4 ppb while the Ka is (2.31±0.1)×105 M-1. The control molecules, C1 and C2 which lack iminophenolic core and calix[6]arene platform respectively have been studied. These do not show considerable changes in their fluorescence emission in presence of Zn2+ implying the essential role of both the arene cavity as well as the role of the three arms to bind to Zn2+. Absorption studies further support the binding of Zn2+ to L by exhibiting isosbestic points at 294 and 344 nm and stoichiometry of the 1:1 complex formed between L and Zn2+ was confirmed by ESI-MS. The computationally optimized structure of {L+Zn2+} complex exhibited distorted octahedral geometry about Zn2+ with N3O3 core. The in situ generated complex, {L+Zn2+} interacts with biologically relevant thiols by exhibiting fluorescence quenching of the complex due to the release of Zn2+ from its complex which is further supported by absorption and ESI-MS studies.
Triazole linked picolylimine conjugate of calix[6]arene as a sequential sensor for La3+ followed by F-
Mummidivarapu, V. V. Sreenivasu,Nehra, Anita,Hinge, Vijaya Kumar,Rao, Chebrolu P.
supporting information; experimental part, p. 2968 - 2971 (2012/09/22)
A new 1,3,5-tris-triazole linked picolylimine conjugate of calix[6]arene (L) has been shown to be selective toward La3+ by turn on fluorescence with ～70-fold enhancement and emits blue, with a minimal detection limit of 65 ± 5 ppb (490 nM). The species of recognition has been modeled computationally to have a monocapped twisted square antiprism with a N6O3 binding core about La3+. The in situ complex of L with La3+ recognizes F- via fluorescence quenching. The reversible response of sensing La3+ and F- sequentially by L has been demonstrated.
