Several novel diazadioxa ferrocenyl derivatives have been prepared along with their previously unknown electroactive precursor [(C5H5)Fe(C5H4CH2N(CH3) (CH2)(2)OCH2-)](2) (2) Di-N,N'-protonated and -methylated species [2(H)(2)][X](2) (3a-c) (X = CF3SO3, BF4, PF6) and [2(Me)(2)][CF3SO3](2) (5), and N-H-N monoprotonated species [2H][X] (4a-c) have been isolated in high yield. The efficient syntheses of compounds [2Na][PF6] (6), [2Cu][CF3SO3] (7), [2Ag][CF3SO3] (8), and [2MCl(2)] (M = Zn, Hg) (9, 10) are reported. The crystal structure of complex 7 has been determined by X-ray analysis at 180 K. Crystal data: monoclinic P2(1)/c, with a = 11.511(2) Angstrom, b = 19.613(2) Angstrom, c = 14.493(2) Angstrom, beta = 88.32(2)degrees, V = 3273.2(1) Angstrom(3), Z = 4; R = 0.034, R-w = 0.039 for 3379 observations and 407 variable parameters. The copper(I) atom, bound to the two O and two N atoms of the ferrocenyl ligand, is in a very distorted tetrahedral geometry with a large N(1)CuN(2) angle (163.1(2)degrees). In cyclic voltammetry, 4a-c undergo two quasi-reversible (Fe(II)/Fe(III)) redox processes at 0.1 V s(-1). Electrochemical studies of 3a-c, 5, 7, and 8 show that diprotonation and dialkylation of 2 or complexation of a Cu(Ag) salt induces an anodic shift ranging from 240 to 110 mV. Chemical oxidation of 2 (5 equiv of Ag(I)) produces the cation [2(H)(2)](4+) (II). The quantitative two-step electrochemical oxidation of 2 at controlled potential in CH3CN also leads to 11: an ECE mechanism, in which the diprotonated species plays a key role, is proposed. Mossbauer data of 2, 3c, 6, 7, 8, and 11 are also presented.