Protonated 3-amino-1,2,4-triazole templated luminescent lanthanide isophthalates with a rare (3,6)-connected topology

Although 3-amino-1,2,4-triazole (AmTAZ) is often used as a ligand, its templating behavior has never been explored. Presented here are a series of isomorphous lanthanide isophthalates, [Ln(ip)(2)(H2O)]center dot(HAmTAZ) (Ln La (1), Sm (2), Tb (3); ip isophthalate, AmTAZ 3-amino-1,2,4-triazole), templated by protonated HAmTAZ(+) cations. The three-dimensional (3D) anionic [Ln(ip)(2)(H2O)](n) framework based on rod-like [Ln(COO)(4)(H2O)] n secondary building units (SBUs) exhibits rare (3,6)-connected (4(2).6)(2)(4(4).6(2).8(7).10(2)) topology, and the guest HAmTAZ+ cations are trapped in the channels. Both compounds 2 and 3 show interesting luminescence properties.