81624-51-3Relevant academic research and scientific papers
Synthesis and Characterization of an Unsymmetrically Bonded Tetrahydroborato Ruthenium Hydride Complex
Mazanec, Terry J.,Letts, John B.,Meek, Devon
, p. 356 - 358 (1982)
The complex RuH(η2-BH4)(ttp) , obtained by treatment of with excess of sodium tetrahydroborate in refluxing tetrahydrofuran, shows discrete 1H n.m.r. signals for the Ru-H protons, each of the two Ru-H-B bridgi
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.
The Synthesis, Characterization, and Reactivity of an Unusual, Amphoteric (Tetrahydroborato)ruthenium Hydride Complex of a Chelating Triphosphine, Ru(H)(η2-BH4)(ttp)
Letts, John B.,Mazanec, Terry J.,Meek, Devon W.
, p. 3898 - 3905 (2007/10/02)
Treatment of x with excess sodium tetrahydroborate in refluxing tetrahydrofuran produces the yellow, microcrystalline complex RuH(η2-BH4)(ttp), 4, which shows discrete proton NMR signals for the metal hydride, each of the two bridging protons, and the two terminal B-H protons at ambient temperature.A variable-temperature 1H NMR study shows scrambling of the BH4- protons at two different temperatures, and the exchange process can be interpreted as a two-step process.Owing to the presence of both Ru-H and doubly bridged Ru-BH4 linkages in 4, addition of acid or base in the presence of neutral ligands L produces two different series of products, i. e., +, L= CO, CH3CN, and P(OMe)3, and RuH2(L)(ttp), L= CO, PPh3, and P(OMe)3.In the case of P(OMe)3, three different isomers (i. e., trans, cis0syn, and cis-anti) are obtained, depending on the sequence of addition of reagents, solvents, and reaction conditions.The cis-syn and cis-anti isomers of + are the first detected examples where the different structures are due to the fixed stereochemical orientatiin of the phenyl group on the central phosphorus atom of ttp.When P(OPh)3 is used as the ligand, the ortho-metalated product RuH(P(OPH)2OPh)(ttp) is obtained instead of the target complex RuH2(P(OPh3)(ttp, analogous to the RuH2(P(OMe)3(ttp) complex.The complexes have been characterized by elemental analyses, conductivity, infrared, proton, and phosphorus-31 NMR spectra, as well as an X-ray structure determination of complex 5d.Complex 4 in the presence of NEt3 catalytically hydrogenates 1-octene to octane at a rate comparable to that of RhCl(PPH3)3; in the presence of 1 equiv of HBF4*Et2O, 4 catalytically hydrogenates 1-octene at a rate ca. 0.75 that of RhCl(PPh3)3.
