In the organometallic silver(I) supramolecular complex poly[[silver(I)-mu(3)-3-[4-(2-thienyl)-2H-cyclopenta[d]pyridazin-1-yl]benzonitrile] perchlorate methanol solvate], {[Ag(C(18)H(11)N(3)S)](ClO(4)).CH(3)OH}(n), there is only one type of Ag(I) center, which lies in an {AgN(2)Spi} coordination environment. Two unsymmetric multidentate 3-[4-(2-thienyl)-2H-cyclopenta[d]pyridazin-1-yl]benzonitrile (L) ligands link two Ag(I) atoms through pi-Ag(I) interactions into an organometallic box-like unit, from which two 3-cyanobenzoyl arms stretch out in opposite directions and bind two Ag(I) atoms from neighboring box-like building blocks. This results in a novel two-dimensional network extending in the crystallographic bc plane. These two-dimensional sheets stack together along the crystallographic a axis to generate parallelogram-like channels. The methanol solvent molecules and the perchlorate counter-ions are located in the channels, where they are fixed by intermolecular hydrogen-bonding interactions. This architecture may provide opportunities for host-guest chemistry, such as guest molecule loss and absorption or ion exchange. The new fulvene-type multidentate ligand L is a good candidate for the preparation of Cp-Ag(I)-containing (Cp is cyclopentadienyl) organometallic coordination polymers or supramolecular complexes.