Ln–Co coordination networks formed with a tridentate nitronyl nitroxide radical linker, namely, {[Ln7(hfac)21Co2(hfac)4(NIT-PhCN)6(H2O)2]·0.5NIT-PhCN}n (LnIII = Gd 1, Tb 2; NIT-PhCN = 2-(4-cyanophenyl)-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl), are reported. These unique coordination networks exhibit an unprecedented structural motif in which six NIT units bridge seven Ln(III) ions to produce linear [Tb7(NIT)6(H2O)2] spin clusters. These are further linked to Co(II) ions by the coordination of CN groups of the radicals, resulting in 2D-coordination networks. DC magnetic susceptibilities of the two complexes are consistent with discrete [Ln7(NIT)6(H2O)2] magnetic units and reveal predominant ferromagnetic interactions between the Ln-NIT centers. The Tb derivative is a zero-field SMM with an SCM-type relaxation process that is thermally activated (Ueff/kB = 27.1 K).