79245-24-2Relevant academic research and scientific papers
DEFINITIVE EXAMPLES OF POLYHYDRIDE COMPLEXES WHICH DO NOT ELIMINATE H2 IN THE PRIMARY PHOTOCHEMICAL REACTION. PHOTODISSOCIATION OF PR3 FROM AND COMPLEXES
Roberts, David A.,Geoffroy, Gregory L.
, p. 221 - 232 (1981)
Irradiation of the complexes (L=PMe2Ph, PMePh2, PPh3) and gives efficient loss of phosphine in the primary photochemical reaction, in contrast to most monomeric polyhydride complexes which lose H2 upon photolysis.The 366 nm quantum yields for the complexes range from 0.13-0.18; the 366 nm quantum yield for PMe2Ph loss from is 0.4.Under an H2 atmosphere, is converted into upon photolysis; the pentahydrides in turn lose another equivalent of phosphine to give the corresponding complexes.The heptahydrides are themselves photosensitive and react to give a mixture of and dimers.Photolysis of degassed solutions of the complexes leads to a complex of , , , and .The efficient photoelimination of L from the complexes is discussed in view of the reported photochemistry of which loses H2 upon irradiation.
N-bonded enolatorhenium(I) complexes having dimethylphenylphosphine ligands as active key intermediates in catalytic Knoevenagel and Michael reactions
Hirano, Masafumi,Hirai, Miwa,Ito, Yuji,Tsurumaki, Tsutomu,Baba, Atsushi,Fukuoka, Atsushi,Komiya, Sanshiro
, p. 3 - 14 (2007/10/03)
Enolatorhenium(I) complexes cis-Re(NCCRCO2R′)(NCCHRCO2R′)(PMe 2Ph)4 (R=H, R′=Me (2a); R=H, R′=Et (2b); R=H, R′=n-Bu (2c); R=Me, R′=Et (2d)) are prepared by the reaction of ReH(N2)(PMe2Ph)4 (1) with alkyl cyanoalkyl carboxylate. X-ray structure analysis of 2b shows that it has an octahedral Re geometry, where mutually cis enolato and ester ligands bind to the rhenium via cyano groups. Reaction of 2b with benzaldehyde gives Re(NCCHCO2Et)[NC(EtO2C)C=CHPh]-(PMe2Ph) 4 (4), which is also derived from the ligand exchange reaction of 2b with ethyl (E)-2-cyano-3-phenylpropenoate. These rhenium(I) complexes 1, 2, and 4 catalyze Knoevenagel and Michael reactions under neutral and mild conditions. A possible mechanism for the Knoevenagel reaction has been proposed.
Synthesis and structure of hydrido bis(ethylene) and hydrido dinitrogen complexes of rhenium(I) having dimethylphenylphosphine ligands
Komiya, Sanshiro,Baba, Atsushi
, p. 3105 - 3110 (2008/10/08)
mer-Hydridobis(ethylene)tris(dimethylphenylphosphine)rhenium(I) (1) and cis-hydrido(dinitrogen)-tetrakis(dimethylphenylphosphine)rhenium(I) (2) have been prepared by the reaction of mer-trichloro-tris(dimethylphenylphosphine)rhenium(I) with ethyllithium and n-propyllithium, respectively. X-ray structure analysis reveals that which complexes are octahedral, and in the former complex the two coordinated ethylenes occupy sites perpendicular to each other in cis positions and in the latter complex hydrido and dinitrogen ligands in cis positions. The coordinated ethylene and dinitrogen can be smoothly displaed by dihydrogen to give known trihydrido- or pentahydridorhenium complexes. Crystal data for 1: space group P1, Z = 2, a = 9.285 (3) ?, b = 19.229 (5) ?, c = 9.044 (3) ?, α = 93.47 (3)°, β = 120.16 (2)°, γ = 90.23 (3)°, V = 1392.5 (8) ?3, R = 0.0653, Rw = 0.0641, based on 3959 reflections with F > 3σ(F). Crystal data for 2: space group P21/a, Z = 4, a = 27.49 (1) ?, b = 10.113 (2) ?, c = 12.235 (6) ?, β = 91.94 (4)°, V = 3424 (2) ?3, R = 0.0464, Rw = 0.0533, based on 4129 reflections with F > 3σ(F).
Structure and reactivity of ReH4(PMe2Ph)4+
Lunder, Diane M.,Green, Mark A.,Streib, William E.,Caulton, Kenneth G.
, p. 4527 - 4531 (2008/10/08)
Protonation of ReH3P4 (P = PMe2Ph) with HBF4·OEt2 in Et2O gives ReH4P4+, which neither exchanges with D2 nor reacts with PhC≡CPh, CO, MeCN, or C2H4 under mild conditions. These results, together with an X-ray crystal structure determination, are consistent with a classical tetrahydride formulation for this cation, and the lack of reactivity correlates with the absence of coordinated H2 as a ligand. NEt3 will not deprotonate ReH4P4+ since it is a weaker base than ReH3P4. The implied electron-rich character of ReH3P4 thus rationalizes why protonation results in formal oxidation to Re(V), rather than retention of Re(III) as in Re(H)2(H2)P4+. The T1 value of the hydrogens bound to rhenium is 97 ms at -70°C and 360 MHz.
