With the ligand 1,5-bis(3,5-dimethylpyrazol-1-yl)-3-thiapentane (bdtp) the compounds [M(bdtp)-(NCS)₂](M = Co or Zn), [Ni(bdtp)(NCS)₂(H₂O)], Cu(bdtp)(F)(BF₄), M(bdtp)Cl₂(M = Co or Cu), Zn(bdtp)Cl₂·0.5EtOH, M(bdtp)(NO₃)₂(M = Co or Cu), Cu(bdtp)X (X = Br or Cl), [Cu(bdtp)]BF₄·H₂O and Ag(bdtp)(NO₃) have been isolated. X-Ray single-crystal structures of [Co(bdtp)(NO₃)₂], Cu(bdtp)Br and Ag(bdtp)(NO₃) were determined. The compound [Co(bdtp)(NO₃)₂] crystallizes in the monoclinic space group P2₁/n, with a= 8.984(2), b= 15.342(3), c= 14.888(3)Å, β= 107.28(2)°, Z= 4 and R 0.038 for 2727 observed [F > 2σ(F)] reflections. The cobalt(II) atom is pseudo-octahedrally co-ordinated by three ligand donors, one mono- and one di-dentate. The Co–N [2.072(3) and 2.083(3)Å] and Co–S bond lengths [2.584(1)Å] are normal. The compound Cu(µ(bdtp)Br crystallizes in the monoclinic space group P2₁/n, with a= 9.017(2), b= 14.09(2), c= 13.660(3)Å, β= 97.80(2)°, Z= 4 and R 0.040 for 1655 observed reflections. The pseudo-tetrahedral co-ordination environment of the copper(I) atom is made up by two pyrazole nitrogens [2.120(5) and 2.014(5)Å], one thioether [2.461(2)Å] and one bromide [2.432(1)Å]. The ligand acts as a link between two successive copper centres, resulting in a polymeric compound structurally isomorphous to Cu(bdtp)Cl. The compound Ag(bdtp)(NO₃) crystallizes in the monoclinic space group P2₁/n, with a= 18.710(4), b= 8.828(2), c= 11.162(5)Å, β= 103.13(3)°, Z = 4 and R 0.038 for 2346 observed reflections. The structure, with bridging ligands, is similar to that of Cu(bdtp)Br. The silver(I) atoms are co-ordinated, in a very distorted-tetrahedral fashion, by two nitrogens [2.483(5) and 2.216(4)Å], one thioether [2.571(2)Å] and a monodentate nitrate anion [2.503(5)Å].