RUTHENIUM CARBONYL-COMPLEXES OF THE BRIDGING TETRADENTATE LIGANDS PH(4)P(2)N(4)S(2) AND PH(4)P(2)N(4)S(2)ME(+)

The reaction of Ru(CO)(4)(C2H4) or Ru(CO)(5) with 1,5-Ph(4)P(2)N(4)S(2 ) in CH2Cl2-hexane at 23 degrees C produces the dimer [RU(CO)2(Ph(4)P( 2)N(4)S(2))](2) (4) in 54% and 11% yields, respectively. The treatment of 4 with methyl triflate (1:1 molar ratio) in dichloromethane yields the mono(N-methylated) derivative )(Ph(4)P(2)N(4)S(2))(Ph(4)P(2)N(4)S (2)Me)][CF3SO3] (5) or, in a 1:2 molar ratio, the dimethylated derivat ive [Ru(CO)(2)(Ph(4)P(2)N(4)S(2)Me)](2)[CF3SO3](2), which exists as a ca. equal mixture of two symmetrical isomers on the basis of H-1 and P -31 NMR, and IR spectra. The reaction of 4 with two equivalents of Me( 3)NO in the presence of acetonitrile generates [Ru(CO)(CH3CN)(Ph(4)P(2 )N(4)S(2))](2), which is also formed as a mixture of isomers in a rati o of ca. 2:1 on the basis of H-1 and P-31 NMR, and IR spectra. The X-r ay structure of 4 . CH2Cl2 shows that the P2N4S2 ring is bonded to one ruthenium through two (geminal) nitrogen atoms and the remote sulfur atom while the second sulfur atom acts as a bridge to the other ruthen ium. The crystals of 4 . CH2Cl2 are triclinic, space group <P(1)over b ar> with a = 12.901(1) Angstrom, b = 13.072(1) Angstrom, c = 10.123(1) Angstrom, alpha = 100.88(1)degrees, beta = 98.90(1)degrees, gamma = 6 7.50(1)degrees, V = 1542.4(3) Angstrom(3), and Z = 2. The final R and R(W) values were 0.040 and 0.027, respectively. The X-ray structure of 5 reveals that N-methylation does not significantly perturb the bondi ng between the heterocyclic ligand and ruthenium. The crystals of 5 ar e triclinic, space group <P(1)over bar> with a = 12.912(6) Angstrom, b = 13.435(7) Angstrom, c = 9.948(3) Angstrom, alpha = 105.04(3)degrees , beta = 102.85(3)degrees, gamma = 70.74(4)degrees, V = 1555(1) Angstr om(3), and Z = 2. The final R and R(W) values were 0.063 and 0.071, re spectively.