A highly sensitive "ON-OFF-ON" dual optical sensor for the detection of Cu(II) ion and triazole pesticides based on novel BODIPY-substituted cavitand

The synthesis with full structural characterization including elemental analysis and 1H, 13C, 11B and 19F NMR, FT-IR and MALDI-TOF spectral data, along with the florescence sensing behavior of a new resorcin[4]arene cavitand 3 bearing multiple BODIPY sites achieved by the Cu-catalyzed azide-alkyne cycloaddition (CuAAC) is being reported. The spatial orientation of multiple BODIPY-1,2,3-triazole arms based on the macrocyclic rigid core is of great interest since the resulting structure has been utilized as a fluorescent chemosensor for numerous metal cations. In particular, a remarkable decrease in the fluorescence emission towards Cu(ii) ions, i.e., "turn-off" response, has been obtained giving rise to an optical sensor for the detection of triazole fungicides, namely tebuconazole, triadimenol, triadimefon, i.e. "turn-on" response. Such a molecular system, hence, can be feasibly applied as a dual optical sensor, i.e. "a turn-on-off-on" system, for dangerous contaminants such as heavy metals and pesticides.

Synthesis of a novel resorcin[4]arene–glucose conjugate and its catalysis of the CuAAC reaction for the synthesis of 1,4-disubstituted 1,2,3-triazoles in water

The Cu(i)-catalyzed azide–alkyne cycloaddition (CuAAC) in aqueous media using resorcin[4]arene glycoconjugate (RG) is reported. The eight β-d-glucopyranoside moieties constructed on the resorcin[4]arene upper rim provide a pseudo-saccharide cavity that offers a suitable host environment for water-insoluble hydrophobic azido and/or alkyne substrates in water. The utility of RG was established as an efficient inverse phase transfer catalyst for the CuAAC in water as a green approach for the synthesis of 1,4-disubstituted 1,2,3-triazole species. The catalytic utility of RG (1 mol%) was demonstrated in a multicomponent one-pot CuAAC for various azido/alkyne substrates. The RG acts as a molecular host and a micro-reactor resulting in the 1,4-disubstituted 1,2,3-triazoles in excellent yield.

The Cu(i)-catalyzed azide–alkyne cycloaddition (CuAAC) in aqueous media using resorcin[4]arene glycoconjugate (RG) is reported.

Multifold ring closing metathesis reactions in the formation of resorcin[4]arene cavitands

The formation of the resorcin[4]arene cavitands by the ring closing metathesis (RCM) reaction depends, to a large extent, on the conformation and the substituents on the upper and lower rim of the perallylated resorcin[4]arenes.