NEW DINUCLEAR AND TRINUCLEAR COMPLEXES OF RUTHENIUM WITH OCTAHEDRA JOINED ON FACES OR EDGES .5. FURTHER STUDY OF EDGE-SHARING BIOCATHEDRAL COMPLEXES OF THE TYPE RU2CL6(PR3)4 (R=ET,BU)

The new compound Ru2Cl6(PEt3)4 (2) has been prepared. The EPR spectra for this and for Ru2Cl6(PBu3)4 (1) have been recorded in frozen CH2Cl2-toluene solution at 77 K. The g values are as follows: (1) g'1 = 2.49, g'2 = 1.83, g1 = 2.28, g2 = 2.07, g3 = 1.91; (2) g'1 = 2.49, g'2 = 1.65, g1 = 2.31, g2 = 2.06, g3 = 1.80. The primed g values are assigned to the quasi-axial Ru(III) center by comparison with data for discrete [trans-RuCl4(PR3)2]-ions. These results support the view previously based on structural and magnetic susceptibility evidence for 1 that the two ruthenium atoms in these molecules are not bonded to each other nor even significantly coupled.