COORDINATION OF POLYTHIAETHER MACROCYCLES TO METAL CLUSTER COMPLEXES .3. SYNTHESIS, STRUCTURE, AND DYNAMICAL ACTIVITY OF THE CLUSTER COMPLEXES RU-3(CO)(7)(MU-CO)(2)(1,1,1-ETA(3)-12S3) AND RU-3(CO)(7)(MU-CO)(2)(1,1,1-ETA(3)-9S3)

The compounds Ru-3(CO)(7)(mu-CO)2(1,1,1-eta(3)-12S3), 1 (12S3 = 1,5,9-trithiacyclododecane), and Ru-3(CO)(7)(mu-CO)(2)(1,1,1-eta(3)-9S3), 2 (9S3 = 1,4,7-trithiacyclononane), were obtained in 83% yields from the reactions of Ru-3(CO)(12) with 12S3 and 9S3, respectively. Both compounds were characterized crystallographically and were shown to possess Fe-3(CO)12-like structures having two bridging CO ligands across one of the Ru-Ru bonds and tridentate 12S3 and 9S3 ligands, respectively. Both compounds exhibit dynamical ligand activity on the NMR time scale at 25 degrees C. The dynamical activity of the CO ligands in 1 was characterized in detail by C-13 NMR spectroscopy through a combination of variable temperature and EXSY magnetization transfer measurements. There is evidence for at least two mechanisms. The lowest temperature process can be explained by a series of bridge-terminal exchange processes involving the CO ligands. Compound 2 was transformed into the new compound Ru-2(CO)(6)(mu-eta(2)-SCH2CH2S), 3 (16%), and the known compound Ru-3(CO)(9)(mu-eta(3)-SCH2CH2SCH2- CH2S), 4 (32%), by degradation of the 9S3 ligand when solutions in THF solvent were heated to reflux. Crystal data for 1: space group = P2(1)/n, a = 9.316(2) Angstrom, b = 15.688(5) Angstrom, c = 16.826(3) Angstrom, beta = 93.30(2)degrees, Z = 4,2217 reflections, R = 0.032. For 2: space group = P2(1)/c, a = 13.976(2) Angstrom, b = 10.123(2)Angstrom, c = 15.538(2) Angstrom, beta = 97.967(9)degrees, Z = 4, 1910 reflections, R = 0.025.