CRYSTAL AND MOLECULAR-STRUCTURES OF TRANS-BIS(ACETONITRILE)BIS(BIPYRIDINE)RUTHENIUM(II) PERCHLORATE AND TRANS-DIAMMINEBIS(BIPYRIDINE)RUTHENIUM(II) PERCHLORATE

The structures of trans-[(MeCN)2(bpy)2Ru](ClO4)2(I) and trans-[(NH3)2(bpy)2Ru] (ClO4)2(II) have been determined by single crystal X-ray diffraction methods. (I) forms monoclinic crystals in the space group P2(1)/c with a = 8.399(2), b = 10.406(2), c = 15.590(3) angstrom, beta = 93.78(2)-degrees and Z = 2 at T = 293 K. The final refinement gave R = 0.040 for 2448 reflections with F(o)2 > 3sigma(F(o)2). (II)crystallizes in the triclinic space group P1BAR with a = 7.702(1), b = 8.439(2), c = 0.525(2) angstrom, alpha = 107.56(2), beta = 104.63(1), gamma = 100.89(2)-degrees and Z = 1 at T = 293 K. Refinement using 1878 reflections with F(o)2 > 3sigma(F(o)2) produced a final R value of 0.036. Both of these structures have the ruthenium atom located on a crystallographic inversion center. The bipyridine ligands in both structures are in the bowed conformation as a means of circumventing the steric problems associated with the trans arrangement of the bipyridine ligands. The Ru-N(monodentate) distance is longer for the ammonia complex (2.106(3) angstrom) than for the acetonitrile complex (2.008(4) angstrom): there are no significant differences in the distances and angles of the two Ru(bpy)2 frameworks.