113975-15-8Relevant academic research and scientific papers
Reactions of [WI2(CO)(NCMe)(η2-RC2R)2] (R = Me, Ph) with pyridines and related ligands. X-ray crystal structure of [WI(CO)(bpy)(η2-MeC2Me)2][BPh4]
Baker, Paul K.,Armstrong, Elaine M.,Drew, Michael G. B.
, p. 2287 - 2291 (2008/10/08)
The complexes [WI2(CO)(NCMe)(η2-RC2R)2] (R = Me, Ph) react with 1 equiv of L (L = py, 3-Cl-py, or 3,5-Me2py) in CH2Cl2 at room temperature to give the substituted products [WI2(CO)L(η2-RC2R)2]. Reaction of [WI2(CO)(NCMe)(η2-MeC2Me)2] with 2 equiv of pyridine was followed by infrared spectroscopy. The initially formed mono(alkyne) complex [WI2(CO)(py)2(η2-MeC2Me)] reacted with the displaced but-2-yne ligand to afford the cationic bis(but-2-yne) complex [WI(CO)(py)2(η2-MeC2Me)2]I. These cationic bis(alkyne) complexes containing monodentate pyridine ligands could not be isolated in a pure state. However, reaction of [WI2(CO)(NCMe)(η2-MeC2Me)2] with 1 equiv of LL (LL = 2,2′-bipyridyl or 1,10-phenanthroline) in CH2Cl2 at room temperature gave good yields of the cationic complexes [WI(CO)(LL)(η2-RC2R)2]I. The cationic complexes [WI(CO)(LL)(η2-RC2R)2][BPh4] (R = Me, Ph; LL = 2,2′-bipyridyl, 1,10-phenanthroline, o-phenylenediamine) were also synthesized by reacting [WI2(CO)(NCMe)(η2-RC2R)2] with LL in the presence of Na[BPh4] in a 1:1:1 molar ratio in CH2Cl2 in order to confirm the ionic nature of these compounds. The structure of [WI(CO)(bpy)(η2-MeC2Me)2][BPh4] has been determined and refined to R = 0.064 (Rw = 0.067) by using 4828 independent reflections above background [crystals were triclinic, space group P1; a = 13.904 (8), b = 10.808 (11), c = 13.596 (12) A?; α = 94.1 (1), β= 96.0 (1), γ = 94.4 (1)°; Z = 2]. The molecule adopts a distorted octahedral geometry with both but-2-yne ligands cis and parallel to each other. The carbon monoxide ligand is trans to the iodide ligand with the remaining two sites being occupied by the bipyridyl nitrogen atoms, which are trans to the but-2-yne ligands. The 13C NMR spectra of the [WI2(CO)L(η2-RC2R)2] and [WI(CO)(LL)(η2-RC2R)2]I type complexes indicate that the two alkyne ligands are donating a total of six electrons to the tungsten atom. The complex [WI2(CO)(NCMe)(η2-PhC2Ph)2] can also react with 2 equiv of bpy followed by 2 equiv of Na[BPh4] in CH2Cl2 at room temperature to give the novel dicationic complex [W(CO)(bpy)2(η2-PhC2Ph)][BPh 4]2. The diphenylacetylene ligand is donating four electrons to the metal in this compound.
