The emerging field of molecular magnetism constitutes a new branch of materials science that deals with the magnetic properties of molecules, or assemblies of molecules, that contain magnetic centers. The growing interest in understanding the origin of the magnetic ordering in these materials is to obtain novel multiproperty molecular magnetic materials with high transition temperatures. Molecules based on the dicyanamide ion [NΞC-N-CΞN], abbreviated (dca), such as M(dca)₂ [M = Mn, Ni], have shown interesting bulk properties that prompted our inelastic neutron scattering (INS) studies. While the Mn²⁺ ion is isotropic because of its L = 0 configuration, the isostructural Ni analog has S = 1 and demonstrates marked single-ion anisotropy. Mn(dca)₂ is a canted antiferromagnet below 16 K, while Ni(dca)₂ is a ferromagnet below 21 K. INS has been used to investigate the magnetic excitations in Mn(dca)₂ and Ni(dca)₂. For Mn(dca)₂, a Heisenberg model gives good correspondence with the experimental results.