Synthesis, Electronic Structure, and Structural Characterization of the New, "Non-Innocent" 4,5-Dithio-Catecholate Ligand, Its Metal Complexes, and Their Oxidized 4,5-Dithio-o-quinone Derivatives.

The bifunctional Iigand estechol-4,5 dithiol, H2Dtcat, has been synthesized, and the structure of the bin Br adduct, (HS)2C6H2(OH)2·2Ph4Br·H2O, has been determined. The syntheses, molecular structures, electronic structures, and magnetic properties of the monoanionic [(Dtcat2-)2M], (M = Ni, V and M o Cu, VI) complexes have been obtained as Ph4PBr double salts, [M(S2C6H2(OH)2)2][Ph4P]3Br2. These and the antiferromagnetically coupled dimetic [(Dtcal)2 Fe][Ph4P]2·4DMF domplex, VII, have been structurally chaiacterized. The centrosymmetric (M(S2C6H2(OH)f complexes in the X-ray isomorphous V and Vi are connected via H-bonding to Br ions to form one-dimensional chains well separated from each other by the Ph4P+ cations. Magnetic measurements show V to be a S o ½ and VI a S = O molecules. The distribution of electrons in these compounds have been determined by density functional theory calculations which show V to be a radical anion Ni(ll) complex and Via partially otddiced-Iigand, reduced-copper complex. The 4,5 dithio-oquinorle [(Dtoq)2Ni][Ph4P]2 and [(Dtoq)2Cu][Ph4P]2 orthoquinone derivatives of V and VI have been obtained by oxidaton, and their molecular structures have been determined. The dimetic ([FeS2C6H2(OH)2)2)2- complex, (VII) also cystallizes in chains where all OH groups partidpate in extensive H-bonding. The structure of the dianion VII contains S-coordinated Fe(Ill) tais in a square pyramidal coordination. In VII, two low spin Fe(III) (S = ½) sites are weakly coupled antitenomagneticalty with a μeff of 2.81BM at 270 K and 0.91 BM at 10 K. [ABSTRACT FROM AUTHOR]