A tetra-nuclear Cu(ii) complex of amide-imine conjugate: highly-selective ESIPT-based probe for OCl^-

A unique tetra-nuclear Cu(ii) complex (C1) was structurally authenticated by single crystal X-ray diffraction; it had a distorted cubane-like core Cu4O4 and was derived from amide-imine conjugate to selectively recognize OCl(-)via inhibition of the ESIPT process, resulting in the induction of fluorescence. The H-bond-assisted strong interaction between C1 and OCl- is reflected by the binding constant, 1.52 x 10(5) M-1, with an LOD of 13.87 nM.