Protonation of diphosphine and phosphite derivatives of dodecacarbonyltriruthenium

Synthesis, characterization, and reactivity of a novel ruthenium carbonyl cluster containing tri-O-benzyl-d-glucal as a chiral carbohydrate ligand

“…1 H NMR spectrum of II in (CD 3 ) 2 CO shows signals corresponding to all of the hydrogens in the organic region as in I, hydrogens due to two triphenylphosphine groups, and two hydride ligands coupled to phosphorus atoms in the high field region. The splitting pattern at d À18.30 indicates the substitution of I by triphenylphosphine occurs at a ruthenium atom that is ÔsigmaÕ bonded to the tribenzyl glucal [1,7]. The variabletemperature 1 H NMR of II in the hydride region is shown in Fig.…”

“…1 H NMR spectrum of III in CDCl 3 shows signals corresponding to all of the hydrogens in the organic region as in I, the hydrogens due to the dppe ligand, and the two bridging hydride ligands coupled to phosphorus atoms in the high field region. The triplet at d À20.62 indicates the bridging hydride ligand between the two equivalent phosphorus nuclei and the doublet at d À16.05 is due to the bridging hydride ligand coupled to a phosphorus atom [7]. FAB+ mass spectrum shows a …”

“…2. The 1 H NMR spectrum at +20°C exhibits a broad resonance at d À18.33, which can be assigned to the two bridging hydride ligands migrating over all three edges of the ruthenium framework in a rapid fluxional process [4,7] as shown in Scheme 1. Upon cooling to À50°C, the broad resonance becomes two sharp singlets at d À16.27 and d À20.41 with the integrated ratio 1:1 similar to the compound [Ru 4 (CO) 13 (l-H) 2 (l 4 -AsCF 3 )] [4].…”

Glycal–ruthenium carbonyl clusters: Syntheses, characterization, and anticancer activity

“…Resonances due to the hydrogen atoms of the L-2H appear at d = 4.80-3.00. There are two equal intensity hydride resonances: a triplet at d = À20.62 with P-H coupling, 2 J P-H = 16.63 Hz, typical of a cis orientation of the equivalent phosphorus atoms of the dppe ligand, and the doublet at d = À16.01 ( 2 J P-H = 35.95 Hz) that is attributed to the second bridging hydride ligand which is trans coupled to one of the phosphorus atoms [17]. The 13 C NMR spectrum of 4 in CD 2 Cl 2 at room temperature shows resonances at d = 205.91, 204.97 (br), 204.35, 200.19, 198.19, 193.83 (br), 193.20 (t, 2 J C-P = 11.5 Hz), 188.95 (br) are due to carbonyl groups that are broad due to dynamical activity.…”

“…Proposed structures for isomers of 3 that are consistent with the spectroscopic data are shown in Scheme 4. The first set of signals with intensity 1 is assigned to the major isomer 3a; a virtual doublet at d = À15.97 [ 2 J P-H = 15.4 Hz] is due to a hydride ligand (located between a ruthenium atom that is 'r' bonded to the L-2H ligand and a ruthenium atom p-bonded to L-2H ligand) with coupling to a phosphorus atom and a virtual triplet which is actually a doublet of doublets at d = À19.58 [ 2 J P-H = 13.7 Hz, 13.7 Hz] that is attributed to the second hydride ligand (positioned between the two-ruthenium atoms that are 'r' bonded to the L-2H ligand) due to coupling to the two inequivalent phosphorus atoms [16,17]. The 13 C NMR spectrum of 3 in CD 2 Cl 2 shows strong resonances in the carbonyl region at d = 204.79, 202.09, 198.42, 195.37, 194.65, 193.54, 193.34 (d, 2 J C-P = 8.0 Hz), 192.35, 188.07 due to carbonyl groups of the major isomer along with weaker resonances at d = 206.67, 197.93, 195.04,192.08, 187.91 due to carbonyl groups of the minor isomer in the mixture, multiplets at d = 139.21-126.93 due to C-1 carbon, the three phenyl groups of L-2H ligand, and the phenyl groups of a triphenylphosphine ligands.…”