Silver(I) sulfate coordination polymers with 4,4′-bipyridazine and pyridazino[4,5-d]pyridazine

Poly[[4-4,4′-bipyridazine-5-sulfato-disilver(I)] mono-hy-drate], {[Ag2(SO4)(C8H6N4)]·H2O} n, (I), and poly[[aqua-4 - pyridazino[4,5-d] pyridazine-3-sulfato-disilver(I)] mono-hydrate], {[Ag2(SO4)(C6H4N4)(H2O)] ·H2O} n, (II), possess three- and two-dimensional polymeric structures, respectively, supported by N-tetra-dentate coordination of the organic ligands [Ag - N = 2.208 (3)-2.384 (3) Å] and O-penta-dentate coordination of the sulfate anions [Ag - O = 2.284 (3)-2.700 (2) Å]. Compound (I) is the first structurally examined complex of the new ligand 4,4′-bipyridazine; it is based upon unprecedented centrosymmetric silver-pyridazine tetra-mers with tetra-hedral AgN2O2 and trigonal-bipyramidal AgN2O3 coordination of two independent Ag^I ions. Compound (II) adopts a typical dimeric silver-pyridazine motif incorporating two kinds of square-pyramidal AgN2O3 Ag^I ions. The structure exhibits short anion-π inter-actions involving noncoordinated sulfate O atoms [O⋯π = 3.041 (3) Å].