Complexes have been formed by the coordination of 2,4,6,8-tetra-tert-butylphenoxazin-1-one (PhenoxBQ) with iron(III) and nickel(II). Addition of PhenoxBQ to a solution of anhydrous FeCl3 gives [Fe(PhenoxBQ)(2)Cl-2](FeCl4). Reduction of this complex occurs at the iminoquinone ligands to give Fe(PhenoxSQ)(2)Cl. Crystallographic characterization (triclinic, P ($) over bar 1, a = 14.151(2) Angstrom, b = 15.170(2) Angstrom, c 16.326(2) Angstrom, alpha = 80.73(1)degrees, beta = 77.28(1)degrees, gamma = 64.54(1)degrees, V = 3077;9(7) Angstrom(3), Z = 2, R = 0.063) has shown that the complex molecule is trigonal bipyramidal in structure with:the chloro ligand bonded in an equatorial site. Radical; iminosemiquinone ligands couple antiferromagnetically with the paramagnetic metal to give a magnetic moment of 3.78 mu(B) for the molecule at room temperature. Cyclic voltammograms show that the complex undergoes two oxidations and two reductions within the potential range +/-1.2 V (vs NHE) that are iminoquinone ligand based and a third reduction at the metal at -1.427 V. Addition of PhenoxBQ to Ni(NO3)(2) gives [Ni(PhenoxBQ)2(NO3)] (NO3). Structural characterization (triclinic, P ($) over bar 1, a = 12.752(2) Angstrom, b = 13.700(2) Angstrom, c = 20.676(3) Angstrom, alpha = 102.03(1)degrees, beta = 98.70(1)degrees, gamma = 114.02(1)degrees, V = 3112.4(8) Angstrom(3), Z = 2, R = 0.072) has shown that the complex cation is octahedral with the nitrate ligand chelated through two oxygen atoms. Reduction of this complex also occurs at the iminoquinone ligands to give Ni(PhenoxSQ)2. This molecule is tetrahedral in structure (monoclinic, P2(1)/c, a = 26.029(5) Angstrom, b = 17.604(6) Angstrom, c 12.118(2) Angstrom, beta = 98.23(1)degrees, V = 5496(2) Angstrom(3), Z = 4, R = 0.066) and diamagnetic, due to strong antiferromagnetic coupling between the radical ligands and the metal ion. Electrochemical characterization has shown that the complex undergoes two oxidations and two reductions that are ligand-based, Coordination of PhenoxBQ results in shifts in nu(CO) and nu(CN) to lower energy with further low-energy shifts upon reduction to PhenoxSQ for complexes of both metals. Lengths of the C-O and C-N bonds within the chelate ring are longer than those of free PhenoxBQ and increase further upon reduction. Reduction couples of the PhenoxBQ and PhenoxSQ ligands are shifted positively by nearly 2.0 V upon coordination, and radical iminosemiquinone ligands couple antiferromagnetically with the paramagnetic metal ions.