Monomeric diaryliron(Il) complexes, Fe(Rind)(2), have been obtained by introducing fused-ring bulky "Rind" groups. For Fe(Eind)(2), a significant orbital contribution of the Fe(II) ion due to the linear two-coordination has been determined by the highly effective magnetic moment (mu(eff) = 5.82 mu(B)) and the extraordinarily large internal hyperfine field (H-n = ca. 140 T) in the Mossbauer spectrum. Variable-frequency out-of-phase ac susceptibility data demonstrate an effective spin-reversal barrier of U-eff = 51.2(7) cm(-1) associated with the single-ion magnet behavior.