Supramolecular Frameworks and a Luminescent Coordination Polymer from New β-Diketone/Tetrazole Ligands

Mixed multidentate linkers with donor groups of different types can be fruitfully exploited in the self-assembly coordination polymers (CPs) and Metal-Organic Frameworks (MOFs). In this work we develop new ligands containing a β-diketone chelating functionality, to better control stereochemistry at metal center, tetrazolyl bridging groups, combination not yet explored for networking ions. The ligands, 1,3-bis(4-(1H-tetrazol-5-yl)phenyl)-1,3-propanedione (H3L1) 1-phenyl-3-(4-(1H-tetrazol-5-yl)phenyl)-1,3-propanedione (H2L2), are synthesized from corresponding nitrile precursors by [2+3] dipolar cycloaddition azide under metal-free catalytic conditions. Crystal structure analysis evidences involvement fragments multiple hydrogen bonding giving 2D 1D supramolecular frameworks. Reactivity salts indicates good coordinating ability, report preparation structural characterization tris–chelate complex [Fe(HL1)3]3− (1) homometallic CP [ZnL2(DMSO)] (2). compound 1 only diketonate is used, whereas partially deprotonated involved bonding, rise framework (6,3)IIa topological type. 2 ligand completely uses both (chelating) tetrazolate fragment (bridging) coordinate Zn(II) resulting neutral network sql topology shows luminescence solid state, which red shifted respect free ligand. Interestingly, it easily exfoliated water give luminescent colloidal solution.