A new topological design of fluorescent probes for sensing copper ion is disclosed. The calix[4]arene-oxacyclophane (Calix-OCP) receptor, either wired-in-series in arylene-alt-ethynylene conjugated polymers or standing alone as a sole molecular probe, display a remarkable affinity and selectivity for Cu(II). The unique recognition properties of Calix-OCP system toward copper cation stem from its pre-organised cyclic array of O-ligands at the calixarene narrow rim, which is kept in a conformational rigid arrangement by a tethered oxacyclophane sub-unit. The magnitude of the binding constants (Ka = 5.30 − 8.52 × 104 M−1) and the free energy changes for the inclusion complexation (−ΔG = 27.0 − 28.1 kJmol−1), retrieved from fluorimetric titration experiments, revealed a high sensitivity of Calix-OCP architectures for Cu(II) species. Formation of supramolecular inclusion complexes was evidenced from UV-Vis spectroscopy. The new Calix-OCP-conjugated polymers (polymers 4 and 5), synthesized in good yields by Sonogashira–Hagihara methodologies, exhibit high fluorescence quantum yields (ΦF = 0.59 − 0.65). Density functional theory (DFT) calculations were used to support the experimental findings. The fluorescence on–off behaviour of the sensing systems is tentatively explained by a photoinduced electron transfer mechanism.

A group of new tetracoordinate mononuclear 2-(N-phenylformimino)pyrrolyl boron chelates [BX2{κ2N,N’-NC4H3-2-C(H)=N-C6H5}] (X=F 3; mesityl (2,4,6-trimethylphenyl, Mes) 4; C6F55; X2=1,1'-biphenyl-2,2'-di-yl 6) and the related binuclear complex [(C6F5)2B{κ2N,N’-NC4H3-2-C(H)=N-C6H4-N=C(H)-C4H3N-κ2N,N’}B(C6F5)2] 7 were synthesised via...

Six new four-coordinate tetrahedral boron complexes, containing the 9-borafluoren-9-yl and diphenylboron cores attached to orthogonal fluorine- and chlorine-substituted 8-quinolinolato ligand chromophores, have been synthesised, characterised, and applied as emitters in...