USING PHOSPHOHYDRAZIDES AS BUILDING-BLOCKS TO MULTIREDOX POLYMETALLICCOMPOUNDS CONTAINING FERROCENYL GROUPS - ELECTROCHEMICAL AND NMR BEHAVIORS IN SOLUTION

The condensation of phosphodi- or phosphotrihydrazides Ph(3-n)P(X)[N(C H3)NH2](n) (1a (n = 2; X = S); 1b (n = 2; X = O); 2a; (n = 3; X = S); 2b (n = 3; X = O)) with ferrocenecarbaldehyde is a high-yield syntheti c route to new ferrocenyl phosphohydrazone ligands Ph(n)P(X)[N(CH3)N=C HC5H4Fe(C5H5)](3-n) (3a, 3b, 4a, 4b). The structure of 3b has been sol ved by X-ray crystallography. Crystal data at room temperature are a = 15.176(1)Angstrom, b = 15.170(2)Angstrom, c = 12.533(2)Angstrom, beta = 106.582(8)degrees, Z = 4 for a monoclinic system, space group P2(1) /c, V = 2765.5(5) Angstrom(3), Z = 4; R = 0.049, R(w) = 0.056 for 2104 observations and 361 variable parameters. Similar phenyl thiophosphod i- and trihydrazones 6 and 7 were obtained by condensation with benzal dehyde. Depending on the ligand/copper(I) ratio 1a, 3a, or 6 led to [L Cu](2)[SO3CF3](2) or [L(2)Cu][SO3CF3] complexes. For the 1/1 adducts t he sulfur atom of the PS group bridges the two copper centers and the P-N-N arms of each ligand are coordinated to two different copper atom s. For the 2/1 adducts each ligand is bonded by the sulfur and one P-N -N arm, and in solution, NMR gives evidence of an exchange phenomenon between the free and complexed P-N-N arms. The ligand 4a is a bidentat e ligand through the sulfur atom with one of the P-N-N arms toward CuC l and a tridentate one through the P-N-N arms toward CuSO3CF3. Condens ation reactions between ferrocenecarbaldehyde and the complexes of la led to the similar complexes containing the ligand 3a. Electrochemical studies of the ligands containing the ferrocenyl moieties and their c omplexes show that complexation induces, as expected, a shift toward m ore anodic potential. For the [(3a)(2)Cu][SO3CF3] complex, two waves c orresponding to the two different ferrocene environments have been obs erved.