We have prepared pi-cation radical complexes of iron(III) and oxoiron(IV) chlorins and examined their electronic structures and magnetic properties by NMR spectroscopy. The high- and low-spin iron(III) pi-cation radicals of tetramesitylchlorin (TMC) exhibit well-resolved hyperfine-shifted NMR resonances, which demonstrates that radical orbitals of these pi-cation radicals are of a(2) type. The hyperfine shifts of the pyrroline ring protons revealed the magnetic interaction between the iron spin and pi-radical spin in the iron(III) TMC pi-cation radicals. The large upfield shift (similar to 174 ppm) of the pyrroline proton resonance for the high-spin iron(III) TMC pi-cation radical implies antiferromagnetic coupling between the iron spin (S = 5/2) and pi-radical spin (S = 1/2). On the other hand, large downfield shift (similar to 460 ppm) for the low-spin iron(III) TMC pi-cation radical is rationalized by very weak antiferromagnetic coupling of the iron (S = 1/2) and pi-radical spin (S = 1/2). The antiferromagnetic coupling of the high-spin complex has been verified by the simulation of the temperature dependence of the pyrroline NMR resonance (J = -60 cm(-1)). While deuterium NMR spectra of the oxoiron(IV) TMC pi-cation radical are consistent with at radical state, the detailed electronic structure is unclear because of failure in detection of the pyrroline deuterium signal. We have also examined the reactivities of the oxoiron(IV) chlorin pi-cation radicals for norbornene by using two types of chlorin complexes, TMC and tetrakis(2,6-dichlorophenyl)chlorin (TDCPC). The oxoiron(IV) pi-cation radicals of both chlorins are less reactive than those of the corresponding tetramesitylporphyrin (TMP) complex. Since the ring oxidation potential of (TDCPC)(FeCl)-Cl-III (1.08 V) is nearly identical with that of (TMP) (FeCl)-Cl-III (1.09 V), the lowered reactivity of the chlorin complexes could not be attributed to the oxidation potentials of the chlorin macrocycles.