Syntheses, structures, and photoluminescent properties of three silver(I) cluster-based coordination polymers with heteroaryldicarboxylate

Three silver(l) cluster-based coordination polymers, namely, [Ag-3(podc)(H2O)].2H(2)O (1), [Ag-2(pidc)] (2), and [Ag-2(pidc)(H2O)] (3) (H(3)podc = 3,5-pyrazoledicarboylic acid and H(2)pidc = 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(l) cluster subunits [Ag...Ag 2.778(1) and 3.230(2) Angstrom]; 2 features new parallel single-strand silver(I) helices that propagate by the 4(1)-screw symmetry with short Ag...Ag contacts [Ag2...Ag2 3.158(1) Angstrom] along the c-axis and display the same handedness, while 3 features hexagonal Ag-4(mu(2)-O)(2) cores, in which the Ag...Ag separation is 3.150(2) Angstrom. These complexes display room temperature photolumineseence 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.