The complexes [Ag₂(L)₂(SO₄)]_∞, (L = 2-aminopyrimidine) 1, [Ag(L)_1.5(ClO₄)]_∞, 2, and [Ag(L)(OAc)·2H₂O]_∞, 3, were prepared by layering the aqueous solution of the corresponding Ag(I) salt with L in ethanol, while [Ag(L′)(NO₃)]_∞, 4, and [Ag(L′)(ClO₄)·H₂O]_∞, 5, were prepared by refluxing AgNO₃ and AgClO₄, respectively, with 2-amino-4,6-dimethylpyrimidine (L′) in H₂O. Reaction of Ag₂SO₄ with L′ in methanol afforded the complex [Ag₄(L′)₂(SO₄)₂(H₂O)₄]_∞, 6. In complex 1, the L ligands are coordinated to the Ag(I) metal centers in new tridentate fashions, forming 2-D pleated molecular sheets which are interlinked by the SO₄²⁻ anions to form a 3-D layer structure. Complex 2 forms a pleated molecular sheet consisting of twenty four-membered metallocycles, involving six Ag ions which are bridged by six L ligands through the pyrimidyl nitrogen atoms. Complex 3 forms linear chains with sinusoidal geometry, which are interlinked through extensive Ag⋯Ag interactions (Ag⋯Ag = 3.102 Å) to form 2-D wavy rectangular grids. Complex 4 forms single-strained helical coordination polymers, which are interlinked through a series of Ag⋯O interactions (2.667 and 2.699 Å) to form 2-D chair like grids. The silver atoms of 5 are bound to the nitrogen atoms of two symmetry-related L′ ligands in a distinctly non-linear geometry, forming zigzag chains. The structure of 6 consists of clusters of the formula [Ag₈(L′)₄(SO₄)₄(H₂O)₈], which are interlinked through L′ ligands to form 2-D sheets. The μ₁-O, μ₂-O′- bonding mode of the SO₄²⁻ anion in complex 6 is unique for Ag(I) complexes. Their thermal properties have been investigated by using differential scanning calorimetry (DSC) and thermogravimetric analyses (TGA)