86664-82-6Relevant academic research and scientific papers
Structural Determination and Acidolysis Reactions of Ortho-Metalated Rhenium Tetrahydride Compounds Prepared from Reactions of ReH7(PPh3)2 with Benzylic Imines
Moehring, Gregory A.,Williams, Christopher C.,Buford, Jeff,Kaviani, Mansoor,Sulko, Jennifer,Fanwick, Phillip E.
, p. 3848 - 3852 (2008/10/08)
Reactions between ReH7(PPh3)2 and a series of benzylic imines, PhCHNR (R = Me, Ph, or Bn), produce the compounds ReH4[η2-(1,2-C6H4)CHNR](PPh 3)2. One such compound, ReH4[η2-(1,2-C6H 4)CHNPh](PPh3)2, was characterized by X-ray diffraction analysis. The compound ReH4[η2-(1,2-C6H 4)CHNPh](PPh3)2 crystallizes in the P1 space group with the following unit cell dimensions: a = 12.422(3) A, b = 12.696(3) A, c = 13.604(5) A, α = 93.26(2)°, β = 90.66(2)°, γ = 107,03(2)°, V = 2047.2 A3, and Z=2. The structure was refined to R(FO) = 0.029 (Rw(FO) = 0.034) for 5352 data with I > 3.0σ(I). The structure determination indicates that ortho-metalation of the imine reactant occurs during the reaction of ReH7(PPh3)2 with PhCHNPh. The observation of four ν(Re-H) absorptions in the infrared spectrum of each ReH4[η2-(1,2-C6H4)CHNR](PPh 3)2 compound indicates that the rhenium-bound hydrogen atoms, in these compounds, are better regarded as classical hydride ligands rather than as elongated dihydrogen ligands. Acidolysis reactions of the compounds ReH4[η2-(1,2-C6H 4)CHNR]-(PPh3)2, with HBF4-Et2O in acetonitrile, result in loss of the ortho-metalated imine ligands from the rhenium coordination spheres and in reduction of the imine functional groups to secondary ammonium cations. One hydride ligand is transferred to the imine carbon atom, during the course of each acidolysis reaction.
Solvento complexes of tungsten, rhenium, osmium, and iridium and the X-ray crystal structure of [IrH2(Me2CO)2(PPh3) 2]BF4
Crabtree, Robert H.,Hlatky, Gregory G.,Parnell, Charles P.,Segmüller, Brigitte E.,Uriarte, Richard J.
, p. 354 - 358 (2008/10/08)
[WH6(PMe2Ph)3], [ReH5(PMe2Ph)3], [ReH7(PPh3)2], [OsH4(PMe2Ph)3], and [IrH5(PPh3)2] react with HBF4 in MeCN (=S) to give [WH2S3(PMe2Ph)3]2+, [ReHS3(PMe2Ph)3]2+, [ReHS4(PPh3)2]2+, [OsS3(PMe2Ph)3]2+, and [IrH2S2(PPh3)2]+ as the BF4 salts. The reaction mechanism and evidence for the initial protonation of some of the d0 polyhydrides at an M-H bond is discussed. In all but the iridium case, MeOH and Me2CO failed to give analogous complexes and no alkane or alkene dehydrogenation reactions were ever observed with the acetonitrile complexes. In the iridium case a variety of solvento complexes can be obtained. Where S = Me2CO, these are active in alkene and alkane dehydrogenation, and in this case a single-crystal X-ray diffraction study was performed: monoclinic unit cell; a = 10.565 (2) ?; b = 25.315 (7) ?; c = 15.460 (4) ?; β = 95.74 (2)°; V = 4114 (4) ?3; space group P21/c; Z = 4; R = 5.6%. The trans influence of the hydride ligands on the O-bound acetone groups was pronounced: Ir-O = 2.228 (5) ? (av), ca. 10% longer than the expected 2.02 ?. This is consistent with the high reactivity of the acetone complex.
Activation of Mono- and Di-nuclear Polyhydrides of Rhenium: Protonation, Solvation, and Oxidation
Allison, Joe D.,Walton, Richard A.
, p. 401 - 403 (2007/10/02)
Activation of the rhenium polyhydrides ReH5(PPh3)2L (L=monodentate ligand) and Re2H8(PPh3)4 has been achieved through their protonation (using HBF4), the formation of solvento-complexes, and their oxidation to reactive paramagnetic cations, strategies which have led to a range of novel species, including 2+, +, and t)2>+ together with their '17-electron' paramagnetic congeners.
