111187-50-9Relevant academic research and scientific papers
Reactions of 5-RC2R)2> (R=Me or Ph) with carbon monoxide to give either 2-MeC2Me)2> or 2-PhC2Ph)2>2. Crystal structure of 2-MeC2Me)2>
Armstrong, Elaine M.,Baker, Paul K.,Drew, Michael G.B.
, p. 377 - 384 (1987)
The complexes 2-RC2R)2> (R=Me and Ph) react in CH2Cl2 with an excess of carbon monoxide to give initially the acetonitrile substituted products 2-RC2R)2>.For R=Me, the complex 2-MeC2Me)2> (1) was isolated and its structure determined by X-ray crystallography.However, for R=Ph, dimerisation occurs to give the iodide-bridged compound 2-PhC2Ph)2>2 (2) with loss of carbon monoxide.These reactions are reversible as 1 and 2 react with acetonitrile to give 2-RC2R)2>.The 13C NMR spectra of 1 and 2 indicate that the two alkyne ligands donate a total of six electrons to the tungsten in these complexes.
Synthesis and spectral properties of [MI2(CO)(NCMe)(η2-RC2R′)2] and [Mo(μ-I)I(CO)(η2-MeC2Me)2]2 bis(alkyne) complexes. X-ray crystal structures of [WI2(CO)(NCMe)(η2-MeC2Me)2] and [WI2(CO)(NCMe)(η2-PhC ...
Armstrong, Elaine M.,Baker, Paul K.,Drew, Michael G. B.
, p. 319 - 325 (2008/10/08)
Full title: Synthesis and spectral properties of [MI2(CO)(NCMe)(η2-RC2R′)2] and [Mo(μ-I)I(CO)(η2-MeC2Me)2]2 bis(alkyne) complexes. X-ray crystal structures of [WI2(CO)(NCMe)(η2-MeC2Me)2] and [WI2(CO)(NCMe)(η2-PhC2Ph)2]. Reaction of the complexes [MI2(CO)3(NCMe)2] (M = Mo or W) with 2 equiv of the alkyne ligands RC2R′ in CH2Cl2 at room temperature (R = R′ = Ph; R = Me, R′= Ph; for M = W, R = R′ = Me, CH2Cl, and p-Tol; R = Ph, R′ = CH2OH) affords high yields of the new bis(alkyne) complexes [MI2(CO)-(NCMe)(η2-RC2R′) 2]. The molybdenum complex [MoI2(CO)(NCMe)(η2-MeC2Me)2] could not be isolated since it rapidly dimerizes with loss of acetonitrile to give the iodide-bridged dimer [Mo(μ-I)I(CO)(η2-MeC2Me)2]2. The analogous tungsten compound is, however, inert to dimerization, even after being refluxed in CHCl3 for 24 h. X-ray single crystallographic studies were carried out on the compounds [WI2-(CO)(NCMe)(η2-RC2R)2] (R = Me and Ph). Crystals of the former (R = Me) are triclinic of space group P1, Z = 2, in a unit cell of dimensions a = 7.282 (8) A?, b = 7.928 (8) A?, c = 15.894 (13) A?, α = 71.8 (1)°, β = 100.7 (1)°, and γ = 87.7 (1)°. Crystals of the latter are monoclinic of space group 12/c, Z = 8, in a unit cell of dimensions a = 31.122 (27) A?, b = 10.470 (9) A?, c = 19.186 (18) A?, and β = 98.5 (1)°. The structures have been refined to R = 0.055 (R = Me) and R = 0.046 (R = Ph) for 2422 and 3283 respective reflections above background. The coordination geometry about the tungsten in each is complex and may be considered to be octahedral, with, as expected, the alkyne ligands parallel to each other and trans to the two iodide ligands, leaving the carbon monoxide and acetonitrile ligands mutually trans. The 13C NMR chemical shifts indicate that the alkyne ligands are donating a total of six electrons to the metal in these complexes.
