Inorganic Chemistry, Vol.37, No.4, 701-707, 1998
Ruthenium(II) complexes with NS2 pyridine-based dithia-containing ligands. Proposed possible structural isomers and X-ray confirmation of their existence
Ligands LX of the type NS2 with S-aryl and S-alkyl substituents which incorporate the unit 2,6-bis(thiomethyl)pyridine are produced. Their reaction with [RuCl2(PPh3)(3)] and [RuCl2(DMSO)(4)] produces the first reported Ru(II)/NS2 complexes. They present the general formulas [RuCl2(LX)L'], where L' = PPh3 or DMSO. Several isomers are possible; however, only two have been found in each reaction. The H-1 NMR spectra show that the HaHb proton atoms of the pyridine-CHaHb-thioether unit are nonisochronous. A Delta delta(HaHb) value close to 1 ppm is observed for the cis complexes while this is smaller for the trans analogues. The possible distinct isomers are discussed in terms of steric effects. It is hypothesized that the trans-dl, the trans-meso, and the cis-meso-E would be the structures more favored. Those structures have been confirmed by X-ray diffraction analysis of trans-dl-[RuCl2(LI)(DMSO)]. 0.5MeOH, cis-[RuCl2(LS)(PPh3)]. CH2Cl2, and trans-meso-[RuCl2(L6)(PPh3)]. 1.5MeOH.
Keywords:NUCLEAR-MAGNETIC-RESONANCE;SULFUR-CONTAINING LIGANDS;CRYSTAL-STRUCTURE;MOLECULAR-STRUCTURE;METAL-IONS;MACROCYCLE;TRIDENTATE;COORDINATION;UNIT;1;4;7-TRITHIACYCLONONANE