Reversible Single‐Crystal to Single‐Crystal Transformation Between Two Copper(II)‐Based Two‐Dimensional Coordination Polymers for Detection of Fe 3+ and 3‐Iodobromobenzene

Abstract A new two‐dimensional copper(II)‐based coordination polymer {[Cu(IBA) 2 ]⋅2DMF} n ( Cu–IBA‐1⋅2DMF ) was successfully obtained through solvothermal reaction with 4‐(1 H ‐imidazol‐1‐yl)benzoic acid (HIBA) as linker. On exposure to air, Cu–IBA‐1⋅2DMF is slowly converted to a new two‐dimensional coordination polymer, namely {[Cu(IBA) 2 ⋅H 2 O]⋅2H 2 O} n ( Cu–IBA‐2⋅2H 2 O ), through a single‐crystal to single‐crystal (SC‐SC) transformation. When suspended in DMF, Cu–IBA‐2⋅2H 2 O regains the initial structure Cu–IBA‐1⋅2DMF , indicating the reversibility of this transformation. Fluorescence spectra measurements show that Cu–IBA‐1⋅2DMF can selectively and sensitively detect Fe 3+ and 3‐iodobromobenzene.