REACTIVITY OF [((ETA-6-ARENE)RUCL(MU-CL))2] TOWARDS SOME POTENTIALLY BIDENTATE LIGANDS - MOLECULAR-STRUCTURE OF [(ETA-6-P-CYMENE)RUCL(TAZ)]PF6 -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-C Npy), o-aminophenol (oap), o-phenylenediamine (opda), p-phenylenediami ne (ppda) and l-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-C Npy (Ia) or oap (IIa)]. [(eta6-C6H6)RuClL2]Cl [L = oap (IIIa); L2 (bid entate) = opda (IVa) or taz (VIa)] or [{(eta6-C6H6)Cl2Ru}2mu-ppda)] (V IIIa). Complexes IVa and VIa undergo anion exchange with KPF6 to give the corresponding hexafluorophosphates (Va and Vlla). The p-cymene ana logues (Ib-VIIIb) have been obtained. Conductance measurements, thermo gravimetry and spectroscopic (IR and H-1 and C-13 NMR) methods have be en used to study the new compounds. The structure of VIIb was determin ed by X-ray diffraction methods. The ruthenium atom of the cation of V IIb is coordinated by the 4-amino (Ru-N = 2.14O(2) angstrom) and 3-thi oxo (Ru-S = 2.354(1) angstrom) groups of the triazine and a chloride l igand (Ru-Cl = 2.394(1) angstrom). The eta6-p-cymene ring completes th e hexacoordination.