The nature of the exchange interactions in three metal-organic coordination networks families is examined. These families have a general form ML2(bpy). Since (bpy) molecules are very long, our networks are reduced to effectively one-dimensional chain systems with very weak interchain interaction. The Bonner–Fisher and Fisher classical spin models are applied to fit the magnetic susceptibility data, and results of the fits are discussed. Metal ions inside MCl2(bpy) and M(N3)2(bpy) interact with ferromagnetic interactions and can be described with Fisher classical spin model, while metal ions in M(ox)(bpy) interact with antiferromagnetic interaction and it can be described with the Bonner–Fisher model. Fitting parameter J produced from our models has higher value in M(N3)2(bpy) than in MCl2(bpy) for the same M. It was found that the total spin value is dominant factor to the strength of the magnetic interaction.