83146-93-4Relevant academic research and scientific papers
Synthetic and mechanistic studies on ruthenium dicarbonyl complexes containing PhP(CH2CH2CH2PCy2) 2 (Cyttp) ligand
Blosser, Patrick W.,Wojcicki, Andrew
, p. 2341 - 2348 (2008/10/09)
A synthetic and mechanistic study is reported on ligand substitution and other reactions of six-coordinate ruthenium(II) carbonyl complexes containing tridentate PhP(CH2CH2CH2PCy2) 2 (Cyttp). Carbonylation of cis-mer-Ru(OSO2CF 3)2(CO)(Cyttp) (1) affords [cis-mer-Ru(OSO 2CF3)(CO)2(Cyttp)]O3SCF3 (2(O3SCF3)) and, on longer reaction times, [cis-mer-Ru(solvent)(CO)2(Cyttp)](O3SCF3) 2 (solvent = acetone, THF, methanol). 2(O3SCF3) reacts with each of NaF, LiCl, LiBr, NaI, and LiHBEt3 to yield [cis-mer-RuX(CO)2(Cyttp)]+ (X = F (3), Cl (4), Br (5), I (6), H (7)), isolated as 3-7(BPh4). These conversions proceed with high stereospecificity to afford only a single isomer of the product that is assigned a structure in which the Ph group of Cyttp points toward the CO trans to X (anti when X = F, Cl, Br, or I; syn when X = H). Treatment of 2(O 3SCF3) with NaOMe and CO generates the methoxycarbonyl complex [cis-mer-Ru(CO2Me)(CO)2(Cyttp)]+ (8), whereas addition of excess n-BuLi to 2(O3SCF3) in THF under CO affords mer-Ru(CO)2(Cyttp) (9). The two 13C isotopomers [cis-mer-Ru(OSO2CF3)(CO)(13CO) (Cyttp)]O3SCF3 (2′(O3SCF3): 13CO trans to PC; 2″(O3SCF3): 13CO cis to all P donors) were synthesized by appropriate adaptations of known transformations and used in mechanistic studies of reactions with each of LiHBEt3, NaOMe/CO, and n-BuLi. Whereas LiHBEt3 reacts with 2′(O3SCF3) and 2″(O3SCF 3) to replace triflate by hydride without any scrambling of the carbonyl ligands, the corresponding reactions of NaOMe-CO are more complex. The methoxide combines with the CO cis to triflate in 2, and the resultant methoxycarbonyl ligand ends up positioned trans to the incoming CO in 8. A mechanism is proposed for this transformation. Finally, treatment of either 2′(O3SCF3) or 2″(O3SCF3) with an excess of n-BuLi leads to the formation of the same two ruthenium(0) isomers of mer-Ru(CO)(13CO)(Cyttp). These products represent, to our knowledge, the first example of a syn-anti pair of isomers of a five-coordinate metal complex.
Syntheses and characterization of ruthenium(0) and ruthenium(II) complexes of two flexible chelating triphosphine ligands
Letts, John B.,Mazanec, Terry J.,Meek, Devon W.
, p. 695 - 704 (2008/10/08)
Treatment of RuCl3·3H2O with the triphosphine ligands PhP(CH2CH2CH2PR2)2 (ttp, R = Ph; Cyttp, R = c-C6H11) produces the complexes [RuCl2(ttp)]x, 1, and RuCl2(Cyttp), 2, respectively. The ttp complex is polymeric whereas the Cyttp product is monomeric, presumably due to steric effects of the larger cyclohexyl (Cy) group. Treatment of 1 with carbon monoxide gives cis and trans carbonyl complexes, depending on the method of preparation; only a trans-dichloro carbonyl complex was obtained in the case of Cyttp. On the basis of infrared data (v(S-O) 1280, 1112 cm-1), the SO2 adduct of 2 has a planar geometry around the sulfur atom. Both chloride ligands of 1 can readily be substituted with CH3CN or CO by using Tl+ as a halogen scavenger; the acetate ion replaces only one chloride in the absence of Tl+. Treatment of 1 with NaBH4 produces RuH(η2-BH4)(ttp), which undergoes substitution reactions to yield the cationic hydrido ligand complexes [RuH(L)(L′)(ttp)]Y (L = P (OCH3)3, PF3, CO, NCCH3; L′ = P(OCH3)3, NCCH3, CO; Y = BF4) by treatment with HBF4 and the appropriate ligands. If the ligand substitution reactions are performed in basic solutions, the ligand dihydrido complexes RuH2(L)(ttp) result. The ruthenium(0) complexes Ru(CO)2(ttp), 10, and Ru(CO)2(Cyttp), 11, can be prepared by (i) Na/Hg reduction of 1 or 2, (ii) reduction of the dicarbonyl complexes [Ru(CO)2(ttp)][BF4]2 or [RuH(CO)2(ttp)]BF4, or (iii) triphosphine substitution of Ru3(CO)12. The complex Ru(CO)2(Cyttp), 11, undergoes oxidative addition reactions with halogens and acids to form the cationic, six-coordinate ruthenium(II) dicarbonyls [RuX(CO)2(ttp)]Y (XY = HCl, HBr, HBF4, Cl2, Br2) and with molecular oxygen to give Ru(CO3)(CO)(Cyttp). The preparation and characterization of these new ruthenium(II) and ruthenium(0) triphosphine complexes are reported, and structures are proposed on the basis of their conductivity, elemental compositions, and infrared, 1H, 31P, and 19F NMR spectroscopy.
