NEW DINUCLEAR AND TRINUCLEAR COMPLEXES OF RUTHENIUM WITH OCTAHEDRA JOINED ON FACES OR EDGES .3. NEW TRINUCLEAR COMPOUNDS OF THE TYPE [(R3P)2CLRUCL3RUCL3RUCL(PR3)2]N (N = 0, +1) - STRUCTURES, EPR SPECTROSCOPY, ELECTROCHEMISTRY, AND MOLECULAR-ORBITALS

We report here the preparation and characterization of four new compounds of the type (R3P)2ClRuCl3RuCl3RuCl(PR3)2 as well as a cationic oxidation product of one of them. The new compounds that have been crystallographically characterized are as follows: Ru3Cl8(PEt3)4 (3), monoclinic, space group P2(1)/n, a = 11.041 (5) angstrom, b = 14.484 (5) angstrom, c = 12.939 (4) angstrom, beta = 102.92 (3)-degrees, V = 2106 (3) angstrom3, Z = 2, Ru-Ru = 2.862 (1) angstrom; Ru3Cl8(PMe3)4 (4a), monoclinic, space group P2(1)/n, a = 13.292 (3) angstrom, b = 7.128 (1) angstrom, c = 16.667 (5) angstrom, beta = 109.16 (2)-degrees, V = 1491.6 (6) angstrom3, Z = 2, Ru-Ru = 2.828 (1) angstrom; Ru3Cl8(PMe3)4.C6H6 (4b), triclinic, space group P1BAR, a = 9.038 (4) angstrom, b = 13.253 (4) angstrom, c = 7.503 (2) angstrom, alpha = 101.31 (2)-degrees, beta = 100.00 (3)-degrees, gamma = 97.09 (3)-degrees, V = 856.2 (5) angstrom3, Z = 1, Ru-Ru = 2.842 (0) angstrom; [Ru3Cl8(PEt3)4][SbF6] (5), monoclinic, space group P2(1)/a, a = 14.558 (5) angstrom, b = 31.81 (2) angstrom, c = 15.049 (6) angstrom, beta = 93.95 (3)-degrees, V = 6952 (9) angstrom3, Z = 6, average Ru-Ru = 2.906 (3) angstrom. In addition, Ru3Cl8(PMe2Ph)4 (2) and the PMe3 (6) and PBu3 (7) homologues of 5 are reported. Together with the previously reported Ru3Cl8(PBu3)4 (1), this gives four such molecules, one (with PMe3) known in two crystal forms. A detailed SCF-X-alpha-SW study of these species is reported and compared with previous results for [Ru3Cl12]4-. The electrochemistry of all four of these molecules and of 5 as well as the EPR spectrum of 5 are presented and discussed. From the electrochemistry as well as by reactions with AgSbF6, Cp2Co, and Na/Hg, it has been shown that besides the neutral molecules the +1, -1, and -2 ions also exist, although only the first has so far been isolated and characterized as compound 5.