Three complexes with the general formula (C6H9N2)2[MIIBr4] with MII = Cu (1), Co (2) and Zn (3) have been grown by the slow evaporation method at room temperature. These compounds were subjected to the following characterization techniques: single crystal X-ray diffraction, thermal analysis (ATG-TD), In situ X-ray powder diffraction and temperature dependent magnetic susceptibility measurements. The crystals of (C6H9N2)2[CuBr4] belong to the triclinic P1¯ space group, whereas (C6H9N2)2[CoBr4] and (C6H9N2)2[ZnBr4] crystallize in the orthorhombic system with the Pbcn space group. Molecular structures of the three coordination compounds consist of [MBr4]2- anions and 2-amino-6-methylpyridinium cations linked together via non-covalent interactions including hydrogen bonding, π···π stacking and halogen···halogen interactions which lead to three-dimensional supramolecular architecture. The thermal decomposition of the copper compound reveals the slow crystallization of CuBr at 130 °C. Both compounds 1 and 2 exhibit weak antiferromagnetic interactions. © 2017 Elsevier B.V.