The tridentate trianion of N,N-bis(2-hydsoxy-di-3,5-tert-butylphenyl)amine H3L3, forms 1:1 and 2:1 complexes with di-, tri-, or tetravalent transition metal ions where it can exist in four oxidation levels (C28H40NO2)(3-,2-,1-0) kwhich are herein designated as L-3, L-2, L-1, and L-0, respectively; (L2)2- and (L-0)(0) are paramagnetic (S = 1/2): whereas the other two are diamagnetic (S = 0). We have synthesized the complexes [Zn(L-2)(NEt3)] (1), green [zn(L-1)(2)] (2), and red [Zn(L-2)(L-0)] (3). Complexes 1, 2 (Girgis, A. Y.; Balch, A. L. Inorg. Chem. 1975, 14, 2724), and 3 have been characterized by X-ray crystallography: 1, orthorhombic, 1ba2, a = 23.194(4) Angstrom, b = 25.132(4) Angstrom, c = 11.741(2) Angstrom, V= 6844(2) Angstrom 3, Z= 8; 2, orthorhombic, C222(1), a = 19.494(3) Angstrom, b =-24.065(4) Angstrom, c = 23.458(4) Angstrom, V = 11004(3) Angstrom(3), Z = 8; 3, triclinic, P (1) over bar, a 11.677(2) Angstrom, b = 12.192(2) Angstrom, c = 20.522(3) Angstrom, alpha = 83.68(2), beta 74.37(2), gamma = 75.40(2)0, V= 2720.0(8) Angstrom(3), Z= 2. Complexes 1 and 3 are paramagnetic with one and two (uncoupled) unpaired electrons per zinc ion (3-290 K), respectively, whereas 2 is diamagnetic. Complexes 2 and 3 are shown to be ligand-based redox isomers. Red 3 converts into the green form 2 in tetrahydrofuran solution under anaerobic conditions via an intramolecular process (k = 0.7 x 10(-3) s(-1) at 23 degrees C; Delta H-double dagger = 15.6 +/- 0.6 kcal mol(-1), Delta S-double dagger = -20.4 +/- 1.8 cal mo(l-) K-1). The electronic structures of 1 and 3 have been investigated by X-band EPR and H-1 NMR spectroscopy. The electro-, spectroelectrochemistry, and magnetochemistry of all complexes are reported.