RECONCILING THE CRYSTAL-STRUCTURE OF [RU(NH3)(6)]CL-3 WITH ITS ESR PROPERTIES

Hexaammineruthenium(III) trichloride forms a Z = 12 monoclinic crystal , which is related to a simple cubic f.c.c. structure by, dominantly, a rotation of a third of the hexaammineruthenium(III) fragments. The c ell contains four crystallographically inequivalent Ru(NH3)(6) fragmen ts, but two are almost identical in conformation and orientation in th e crystal. In the ESR spectrum only three resolvable crystallographica lly different ions are thus predicted, not four. This is what is obser ved.