{CpFeII(CO)2SnII(Macrocycle•3–)} Radicals with Intrinsic Charge Transfer from CpFe(CO)2 to Macrocycles (Cp: Cp or Cp*); Effective Magnetic Coupling between Radical Trianionic Macrocycles•3–

Neutral {CpFe II (CO) 2 [Sn II (Pc •3- )]} {Cp is cyclopentadienyl ( 1 , 2 ) or Cp* is pentamethylcyclopentadienyl ( 3 ); Pc: phthalocyanine}, {Cp*Fe II (CO) 2 [Sn II (Nc •3- )]} ( 4 , Nc: naphthalocyanine), and {CpFe II (CO) 2 [Sn II (TPP •3- )]} ( 5 , TPP: tetraphenylporphyrin) complexes in which CpFe II (CO) 2 fragments (Cp: Cp or Cp*) are coordinated to Sn II (macrocycle •3- ) have been obtained. The product complexes were obtained at the reaction of charge transfer from CpFe I (CO) 2 (Cp: Cp or Cp*) to [Sn II (macrocycle 2- )] to form the diamagnetic Fe II and paramagnetic radical trianionic macrocycles. As a result, these formally neutral complexes contain S = 1/2 spins delocalized over the macrocycles. This provides alternation of the C-N imine or C-C meso bonds in the macrocycles, the appearance of new bands in the near-infrared spectra of the complexes, and blue shift of both Soret and Q-bands. The {CpFe II (CO) 2 Sn II (macrocycle •3- )} units (Cp: Cp or Cp*, macrocycle: Pc or Nc) form closely packed π-stacking dimers in 1 and 3 or one-dimensional chains in 2 and 4 with effective π-π interaction between the macrocycles. Such packing allows strong antiferromagnetic coupling between S = 1/2 spins. Magnetic interaction can be described well by the Heisenberg model for the isolated dimers in 1 and 3 with exchange interaction J / k B = -78 and -85 K, respectively. Magnetic behavior of 2 and 4 is described well by the model that includes contributions from an antiferromagnetically coupled S = 1/2 dimer ( J intra ) and a Heisenberg S = 1/2 chain with alternating antiferromagnetic spin exchange between the neighbors ( J inter ). Compound 2 demonstrates large intradimer interaction of J intra / k B = -54 K and essentially weaker interdimer exchange interactions of J inter / k B = -6 K, whereas compound 4 shows strong magnetic coupling of spins within the dimers ( J intra / k B = -170 K) as well as between the dimers ( J inter / k B = -40 K). Compound {CpFe II (CO) 2 [Sn II (TPP •3- )]} ( 5 ) shows no π-π interactions between the porphyrin macrocycles, and magnetic coupling is weak in this case (Weiss temperature is -5 K). Preparation of a similar complex with indium(III) chloride phthalocyanine yields {CpFe(CO) 2 [In(Pc 2- )]} ( 6 ). In this complex, indium(III) atoms are reduced instead of the phthalocyanine macrocycles that explains electron paramagnetic resonance silence of 6 in the 4-295 K range.