New ligand, N 2-(6-aminopyridin-2-yl)-N 6-(pyridin-2-yl)pyridine-2,6-diamine (abbreviated as tripyridyltriamine-H 3 tptra) (1), its protonated analog [H 4 tptra](ClO 4) (2) and copper(II) (3), nickel(II) (4), iron(II) (5) and cobalt(II) (6) complexes have been synthesized and structurally characterized. The protonated ligand cation (2) exhibits an anti-anti-syn-anti-syn conformation. H 3 tptra coordinates to the Cu(II) as a quadridentate ligand in 3. The copper(II) ion is six-coordinated in an elongated octahedral coordination geometry. The perchlorate anions are relatively weakly coordinated in the axial positions. In complexes Ni(II), Fe(II) and Co(II) two ligands are bound directly to the metal ion as tridentate to give a MN 6 chromophore (M-metal atom). Extensive hydrogen bonds are formed and construct the compound 2 into 1D and 3 into 3D supramolecular structure, whereas dimer structure have been found for 4 and 5 complexes through hydrogen bonds. X-band EPR spectra of Cu(II) complex showed well-resolved hyperfine structure resulting from the two paramagnetic isotopes 63 Cu and 65 Cu (g = 2.128 and A 0 = 62.7 × 10-4 cm-1) and also superhyperfine coupling from four 14 N (I = 1) atoms, yielding A // N = 16 × 10-4 cm-1 and A ⊥ N = 9 × 10-4 cm-1. The magnetic behavior of 6 obeys the Curie-Weiss law. The best fitting result according to the Curie-Weiss expression leads to a value of g = 2.49 and θ = −3.71 K.