Ligand-Rearrangement-Induced Transformation from a 3D Supramolecular Network to a Discrete Octanuclear Cluster: A Good Detector for Pb²⁺ and Cr₂O₇^2–

A three-dimensional supramolecular framework containing both left- and right-handed helixes, {[Zn­(TTPA)­Cl2]·1.63H2O}n (1), has been converted to a novel octanuclear cluster containing a metal–organic framework, [Zn8(ptptp)6Cl2]­(ClO4)2·4CH3OH·2H2O (1b), induced by ligand rearrangement during a solvothermal process. The luminescent properties of 1b indicate that the material can act as a selective probe toward Pb2+ and Cr2O72–.