New precursors to potentially conductive noninteger oxidation state (NIOS) compounds based on metal complexes [ML(2)](n-) [M = Ni, Pd, Pt; L = 5,6-dihydro-1,4-dithiin-2,3-dithiolato (dddt(2-)), 5,7-dihydro-1,4,6-trithiin-2,3-dithiolato (dtdt(2-)), and 2-thioxo-1,3-dithiole-4,5-dithiolato (dmit(2-)); n = 2, 1, 0] have been investigated. Complexes of the series (NR(4))[ML(2)] (R = Me, Et, Bu; L = dddt(2-), dtdt(2-)) have been isolated and characterized, and the crystal structure of (NBu(4))[Pt(dtdt)(2)] (1) has been determined {1 = C24H44NPtS10, a = 12.064(2) Angstrom, b = 17.201(3) Angstrom, c = 16.878(2) Angstrom, beta = 102.22(2)degrees, V = 3423(1) Angstrom(3), monoclinic, P2(1)/n, Z = 4}. Oxidation of these complexes affords the corresponding neutral species [ML(2)](0). Another series of general formula (cation)(n)[M(dmit)(2)] [cation = PPN+, BTP+, and (SMe(y)Et(3-y))(+) with y = 0, 1, 2, and 3, n = 2, 1, M = Ni, Pd] has also been studied. All of these (cation)(n)[M(dmit)(2)] complexes have been isolated and characterized [with the exception of (cation)[Pd(dmit)(2)] for cation = (SMe(y)Et(3-y))(+)]. The crystal structures of (PPN)[Ni(dmit)(2)].(CH3)(2)CO (2) and (SMeEt(2))[Ni(dmit)(2)] (3) have been determined {2 = C45H36NNiS10P2O, a = 12.310(2) Angstrom, b = 13.328(3) Angstrom, c = 15.850(3) Angstrom, alpha = 108.19(3)degrees, beta = 96.64(2)degrees, gamma = 99.67(2)degrees, V = 2373(1) Angstrom(3), triclinic, <(P)over bar 1>, Z = 2; 3 = C11H13NiS11, a = 7.171(9) Angstrom, b = 17.802(3) Angstrom, c = 16.251(3) Angstrom, beta = 94.39(4)degrees, V = 2058(2) Angstrom(3), monoclinic, P2(1)/n, Z = 4} NIOS salts derived from the preceding precursors were obtained by electrochemical oxidation. Electrochemical studies of the [M(dddt)(2)] complexes show that they may be used for the preparation of NIOS radical cation salts and [M(dddt)(2)][M’(dmit)(2)](x) compounds, but not for the preparation of (cation)[M(dddt)(2)](z) NIOS radical anion salts.The electrochemical oxidation of the [M(dtdt)(2)](-) complexes always yields the neutral [M(dtdt)(2)](0) species. The crystal structure of [Pt(dddt)(2)][Ni(dmit)(2)](2) (4) has been determined and is consistent with the low compaction powder conductivity (5 x 10(-5) S cm(-1) at room temperature) {4 = C20H8Ni2PtS28, a = 20.336(4) Angstrom, b = 7.189(2) Angstrom, c = 14.181(2) Angstrom, beta = 97.16(2)degrees, V = 2057(1) Angstrom(3), monoclinic, C2/m, Z = 2}. The crystal structures of the semiconducting NIOS compounds (BTP)[Ni(dmit)(2)](3) (5) and (SMe(3))]Ni(dmit)(2)](2) (6) have been determined {5 = C43H22PNi3S30, a = 11.927(2) Angstrom, b = 24.919(2) Angstrom, c = 11.829(3) Angstrom, alpha = 93.11(1)degrees, beta = 110.22(1)degrees, gamma = 83.94(1)degrees, V = 3284(1) Angstrom(3), triclinic, , Z = 2; 6 = C15H9Ni2S21, a = 7.882(1) Angstrom, b = 11.603(2) Angstrom, c = 17.731(2) Angstrom, alpha = 77.44(1)degrees, beta = 94.39(1)degrees, gamma = 81. 27(1)degrees, V = 1563(1) Angstrom(3), triclinic, , Z = 2}. The parent compound (SEt(3))[Ni(dmit)(2)](z) (unknown stoichiometry) is also a semiconductor with a single-crystal conductivity at room temperature of 10 S cm(-1). By contrast, the single-crystal conductivity at room temperature of (SMeEt(2))[Pd(dmit)(2)](2) (7) is rather high (100 S cm(-1)). 7 behaves as a pseudometal down to 150 K and undergoes an irreversible metal-insulator transition below this temperature. The crystal structure of 7 has been determined {7 = C17H13NPd2S21, a = 7.804(4) Angstrom, b = 36.171(18) Angstrom, c = 6.284(2) Angstrom, alpha = 91.68(4)degrees, beta = 112.08(4)degrees, gamma = 88.79(5)degrees, V = 1643(1) Angstrom(3), triclinic, , Z = 2}. The electronic structure of (SMeEt(2))[Pd(dmit)(2)](2) (7) and the possible origin of the metal-insulator transition at 150 K are discussed on the basis of tight-binding band structure calculations.