Reaction systems with a constant 2:1 Na2edt:M(II,III) mole ratio (edt = ethane-1,2-dithiolate) have been shown to yield the following complexes, isolated as quaternary ammonium salts: [Ti(edt )3]2™ (1), [V2(edt)4]2" (2), [Cr(edt)2]2" (3), [Mn(edt)2]2' (4), [Mn2(edt)4]2-(5), [Fe2(edt)4]2" (6), [Co(edt)2]2" (7), [Co(edt)2]" (8), [Ni2(edt)3]2" (9), [Cu3(edt)3]3-(10), [Zn(edt)2]2" (11), and [Cd(edt)2]2" (12). The following compounds have been structurally characterized by single-crystal X-ray diffraction (space group; crystal parameters; Z; unique data (/ > (2-3)[

No abstract

M-X stretching constant force.From the data available we are not able to assess the contribution of the impurities to the conduction mechanism.To summarize, this is the first reported example of this type of linear-chain nickel compounds.28The only example where mixed-valence Ni ions are present is in the class of compounds having the formula L¡xNi¡_x0.29 The higher oxidation state, Niln or NiIV, occurs in few compounds, all of them having coordination numbers of 5 or 6, and are present, in the solid state, as discrete molecules.30•31

The first systematic investigation of Mn-thiolate complexes is described. Anaerobic reaction of MnCl2 with 2.5 equiv of NaSPh in methanol affords [Mn4(SPh)10]1 2". The compound (Me4N)2[Mn4(SPh)10] crystallizes in triclinic space group PI with a = 13.184 (3) A, b = 23.743 (4) A, c = 12.930 (3) A, a = 91.63 (2)°, ß = 113.76 (1)°, y = 79.53 (2)°, and Z = 2. The structure was refined to R (Pw) = 4.5% (4.8%) with use of 5787 unique data (I > 3 (/)). The anion contains an adamantane-like 4(µ-8)6 cage composed of a nearly regular Mn4 tetrahedron and an irregularly distorted S6 octahedron and exhibits terminal and bridging Mn-S mean distances of 2.376 (7) and 2.46 (2) Á, respectively. Selected structural features are compared with those of five other 4(µ-8)6 cages. Anaerobic reaction of MnCl2 with 2 equiv of Na2(l,2-S2C2H4) in methanol forms extremely oxygen-sensitive [Mn(S2C2H4)2]2~. The compound (Me4N)2[Mn(S2C2H4)2]-MeCN crystallizes in monoclinic space group P2\/n with a = 9.833 (5) A, b = 17.325 (7) A, c = 13.819 (6) A, ß = 93.43 (2)°, and Z = 4. The structure was refined to R (Pw) = 4.4% (4.5%) with use of 1893 unique data (I > 3 (/)). The anion is tetrahedral with mean dimensions Mn-S = 2.432 (7) Á, chelate ring zS-Mn-S = 91.5°, and a 92.3°dihedral angle between MnS2 planes. Exposure of a solution of [Mn(S2C2H4)2]2~t o air results in the immediate formation of a dark green color and thereafter isolation of salts of [Mn2(S2C2H4)4]2'. (Et4N)2[Mn2(S2C2H4)4] crystallizes in monoclinic space group P2Jn with a = 12.039 (4) A, b = 10.699 (2) A, c = 15.012 (3) X, ß = 110.89 (2)°, and Z = 2. The structure was refined to R (R") = 4.4% (4.9%) with use of 2175 unique data (/ > 3 (/)). The centrosymmetric anion exhibits the lateral dimer structure in which bis chelate monomers are joined by two Mn-S bonds of length 2.632 (2) Á. The two Mn-Ss coordination units approach a trigonal-bipyramidal arrangement and are separated by a Mn-Mn distance of 3.596 (3) Á. [Mn2(S2C2H4)4]2™ is the first characterized Mn(III) thiolate. A compilation of the limited set of all known Mn-S bond distances is provided.[Mn(S2C2H4)2]2-and [Mn4(SPh)10]2" contain tetrahedral Mn(II) sites; [Mn(S2C2H4)2]2" remains tetrahedral and high spin in acetonitrile and DMF solutions. Magnetic and spectral properties of solutions prepared from [Mn2(S2C2H4)4]2ĩ ndicate that the dimer partially (acetonitrile) or completely (Me2SO, DMF) dissociates in solution to form monomeric [Mn(S2C2H4)2(solv)2]_. Cyclic voltammetry of these species are in accord with an E¡C¡ mechanism, in which the initial reduction product, [Mn(S2C2H4)2(solv)2]2~, rapidly and irreversibly converts to [Mn(S2C2H4)2]2~. This species is irreversibly oxidized to [Mn(S2C2H4)2(solv)2]~a t less cathodic potentials. The large £ values (0.52 V (acetonitrile), 0.76 V (DMF)) are consistent with different electroactive orbitals of [Mn(S2C2H4)2]2~a nd [Mn(S2C2H4)2(solv)2]~required by tetrahedral and six-coordinate structures, respectively. Spectral evidence is presented for Mn(III) species of the type [Mn(S2C2H...

No abstract

No abstract

No abstract

No abstract