{CpFe(CO)Sn(Macrocycle)} Radicals with Intrinsic Charge Transfer from CpFe(CO) to Macrocycles (Cp: Cp or Cp*); Effective Magnetic Coupling between Radical Trianionic Macrocycles.

Neutral {CpFe(CO)[Sn(Pc)]} {Cp is cyclopentadienyl (, ) or Cp* is pentamethylcyclopentadienyl (); Pc: phthalocyanine}, {Cp*Fe(CO)[Sn(Nc)]} (, Nc: naphthalocyanine), and {CpFe(CO)[Sn(TPP)]} (, TPP: tetraphenylporphyrin) complexes in which CpFe(CO) fragments (Cp: Cp or Cp*) are coordinated to Sn(macrocycle) have been obtained. The product complexes were obtained at the reaction of charge transfer from CpFe(CO) (Cp: Cp or Cp*) to [Sn(macrocycle)] to form the diamagnetic Fe and paramagnetic radical trianionic macrocycles. As a result, these formally neutral complexes contain = 1/2 spins delocalized over the macrocycles. This provides alternation of the C-N or C-C 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(CO)Sn(macrocycle)} units (Cp: Cp or Cp*, macrocycle: Pc or Nc) form closely packed π-stacking dimers in and or one-dimensional chains in and with effective π-π interaction between the macrocycles. Such packing allows strong antiferromagnetic coupling between = 1/2 spins. Magnetic interaction can be described well by the Heisenberg model for the isolated dimers in and with exchange interaction / = -78 and -85 K, respectively. Magnetic behavior of and is described well by the model that includes contributions from an antiferromagnetically coupled = 1/2 dimer ( ) and a Heisenberg = 1/2 chain with alternating antiferromagnetic spin exchange between the neighbors ( ). Compound demonstrates large intradimer interaction of / = -54 K and essentially weaker interdimer exchange interactions of / = -6 K, whereas compound shows strong magnetic coupling of spins within the dimers ( / = -170 K) as well as between the dimers ( / = -40 K). Compound {CpFe(CO)[Sn(TPP)]} () 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)[In(Pc)]} (). In this complex, indium(III) atoms are reduced instead of the phthalocyanine macrocycles that explains electron paramagnetic resonance silence of in the 4-295 K range.