Toward a New Type of Multifunctional Metal–Organic Systems Based on Nucleobase Analogues: First Results Derived From The Use of Aliphatic α,ω-Dicarboxylates

Five new transition metal complexes, containing the purine-mimetic ligands 7-amine-1,2,4-triazolo­[1,5-<i>a</i>]­pyrimidine (7atp) and 4,5-dihydro-5-oxo-1,2,4-triazolo­[1,5-<i>a</i>]­pyrimidine (5HtpO), and also malonate (mal<sup>2–</sup>) and succinate (suc<sup>2–</sup>) as secondary ligands are reported. Their formula are [Mn<sub>2</sub>(μ-7atp)<sub>2</sub>(μ-mal)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>] (<b>1</b>), [Zn<sub>2</sub>(μ-7atp)<sub>2</sub>(μ-mal)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>] (<b>2</b>), [Cu<sub>2</sub>(5HtpO)<sub>2</sub>(mal)<sub>2</sub>(H<sub>2</sub>mal)<sub>2</sub>(μ-H<sub>2</sub>O)<sub>2</sub>] (<b>3</b>), [Cu<sub>2</sub>(μ-5tpO)<sub>2</sub>(μ-Hsuc)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>] (<b>4</b>), and [Cd<sub>2</sub>(μ-5tpO)<sub>2</sub>(μ<sub>4</sub>-suc)­(H<sub>2</sub>O)<sub>2</sub>]<sub><i>n</i></sub> (<b>5</b>). Single-crystal X-ray analysis show that compounds <b>1</b>–<b>4</b> feature all dinuclear units with different topologies while compound <b>5</b> exhibits a 3D-network with small-diameter pores. The variety of coordination modes displayed by both triazolopyrimidine derivatives together with the bridging capability of the aliphatic α,ω-dicarboxylates used lead to compounds with interesting structural features and physical properties. The Cu­(II) malonate dimer <b>3</b> exhibits weak ferromagnetic interactions (<i>J</i> = +1.5 cm<sup>–1</sup>) while a weak and a moderately strong antiferromagnetism are displayed, respectively, in the Mn­(II) (<i>J</i> = −2.1 cm<sup>–1</sup>) and Cu­(II) succinate dimer <b>4</b> (<i>J</i> = −109.7 cm<sup>–1</sup>). On the other hand, solid-state photoluminescent emission is observed for the Zn­(II) compound with a Stokes shift of 73 nm.