Syntheses, Structures, and Photoluminescent Properties of Three Silver(I) Cluster-Based Coordination Polymers with Heteroaryldicarboxylate

Three silver(I) cluster-based coordination polymers, namely, [Ag3(podc)(H2O)2]·2H2O (1), [Ag2(pidc)] (2), and [Ag2(pidc)(H2O)] (3) (H3podc = 3,5-pyrazoledicarboylic acid and H2pidc = 2,3-pyrazinedicarboxylic acid) have been synthesized. Among them, 1 consists of stairlike one-dimensional chains with boxlike units as well as the zigzag tetranuclear silver(I) cluster subunits [Ag···Ag 2.778(1) and 3.230(1) Å]; 2 features new parallel single-strand silver(I) helices that propagate by the 41-screw symmetry with short Ag···Ag contacts [Ag2···Ag2 3.158(1) Å] along the c-axis and display the same handedness, while 3 features hexagonal Ag4(μ2-O)2 cores, in which the Ag···Ag separation is 3.150(2) Å. These complexes display room temperature photoluminescence in the blue/green region, which may be assigned to an admixture of ligand-to-metal charge transfer and metal-centered (d−s/d−p) transitions.