[en] Ferromagnetic polycrystalline Fe[Se₂CN(C₂H₅)₂]₂Cl is examined, as are several dilute versions of it containing diamagnetic Zn[S₂CN(C₂H₅)₂]₂, present to the extents 3.6, 7.9, 13.7 and 20.2%. The magnetic ordering temperature decreases much less rapidly with dilution than predicted by any standard model such as the nearest neighbor 3D Ising, XY and Heisenberg ones, and the initial slope -(dT_c/dx)/T_c is well below unity. A curvature change of T_c(x) appears at approximately 14% dilution. Extensions of simple models do not account for the results. It is possible, perhaps, that molecular shape factors lead to effectively nonrandom dilution, unexpectedly surviving ferromagnetic interactions, and thus to the unprecedented T_c(x)