REACTIVITY OF [((ETA-6-ARENE)RUCL(MU-CL))2] TOWARDS SOME POTENTIALLY BIDENTATE LIGANDS - MOLECULAR-STRUCTURE OF [(ETA-6-P-CYMENE)RUCL(TAZ)]PF6 (P-CYMENE=P-MEC6H4CH-ME2-TAZ=2,6-DIMETHYL-5-OXO-3-THIOXO-2,3,4,5-TETRAHYDRO-1,2,4-TRIAZINE)

Reactions of [{(eta6-arene)RuCl(mu-Cl)}2] [arene = benzene or p-cymene (p-isopropyltoluene)] have been carried out with 4-cyanopyridine (4-CNpy), o-aminophenol (oap), o-phenylenediamine (opda), p-phenylenediamine (ppda) and 2,6-dimethyl-5-oxo-3-thioxo-2,3,4,5-tetrahydro-1,2,4-triazine (taz). The isolated complexes are of the types [(eta6-C6H6)RuCl2L] [L = 4-CNpy (Ia) or oap (IIa)]. [(eta6-C6H6)RuClL2]Cl [L = oap (IIIa); L2 (bidentate) = opda (IVa) or taz (VIa)] or [{(eta6-C6H6)Cl2Ru}2mu-ppda)] (VIIIa). Complexes IVa and VIa undergo anion exchange with KPF6 to give the corresponding hexafluorophosphates (Va and Vlla). The p-cymene analogues (Ib-VIIIb) have been obtained. Conductance measurements, thermogravimetry and spectroscopic (IR and H-1 and C-13 NMR) methods have been used to study the new compounds. The structure of VIIb was determined by X-ray diffraction methods. The ruthenium atom of the cation of VIIb is coordinated by the 4-amino (Ru-N = 2.14O(2) angstrom) and 3-thioxo (Ru-S = 2.354(1) angstrom) groups of the triazine and a chloride ligand (Ru-Cl = 2.394(1) angstrom). The eta6-p-cymene ring completes the hexacoordination.