Bivalent ion interaction Studying the reactions of Co (II), Ni (II), Cu (II), and Zn (II) with 4,6-dihydroxy-2-mercaptopyrimidine (DHMP) in the presence of oxalic acid (Ox), malonic acid (Mal), o-phenylene diamine (OPDA), 2,2-bipyridyl (Bipy), 1,10-phenanthroline (phen), and ethylene diamine (En). Compounds of the solid form M-2-MeO-Bz have been synthesised; M denotes the bivalent metals Mn, Co, Ni, Cu, and Zn, while 2-MeO-Bz is 2-methoxybenzoate. Differential scanning calorimetry (DSC), X-ray powder diffractometry, thermogravimetry, and derivative thermogravimetry were all utilised to describe and evaluate the thermal behaviour of these substances.