- Synthesis, properties and structures of complexes of platinum metal halides and Group 11 metals with two distibinomethane ligands, R2SbCH2SbR2 (R = Me or Ph)
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The reaction of [Ru(dmf)6][CF3SO3]3> LiX and Ph2SbCH2SbPh2 (dpsm) yielded trans-[RuX2(η1-dpsm)4] (X = Cl or Br) or [RuI2(η1-dpsm)2(η2-dpsm)]. The latter was shown by an X-ray study to contain two monodentate and one chelating dpsm ligands and is the first example with any metal of a distibinomethane acting as a chelate to be authenticated crystallographically. The chelate ring is highly strained as shown by the Sb-Ru-Sb angle (74.3°) and the longer Ru-Sb distances than in the η-ligands. Corresponding reactions of 15-[OsX2(dmso)4] and dpsm produced trans-[OsCl2Os-dpsm)n] and [OsBr2(η-dpsm)2(;/2-dpsm)] identified spectroscopically. The reactions of RhX3 (X = Cl, Br or I) with dpsm afford [RhX3(dpsm)2] which on the basis of NMR spectroscopic data contain one chelating and one monodentate dpsm ligand. Palladium(n) and platinum(n) halides form both 1:1 and 1:2 complexes with dpsm. The former are dimeric and crystal structures of [M2X4(dpsm)J (M = Pt, X = Cl or Br; M = Pd, X = Br) revealed a distibine bridged structure with square-planar MX2Sb2 metal centres, one with a cis geometry, the other trans. The structures cw, H£-[X2M(n-dpsm)2MX2] are the first examples of this geometry to be established crystallographically. In contrast [I2M(μ-dpsm)2MI2] are assigned as trans,trans isomers on the basis of spectroscopic data. Multinuclear NMR studies show that [PtX2(dpsm)2] (X = Cl or Br) contain //'-dpsm and are a mixture of m and trans isomers in solution, but the [PtI2(dpsm)2] contains only a single form, probably the trans isomer. The [PdX2(dpsm)2] have also been characterised and for X = Cl shown to undergo facile fragmentation in solution to form trans,trans-[Pd2Cl2(2Cl2(CO)2(μ-L-L)J have also been prepared. All complexes have been characterised by analysis, IR, UV-VIS, multinuclear NMR (1H, 13C-{1H}, 195Pt, 12Cu and I09Ag) spectroscopies as appropriate. Comparisons are drawn between the various co-ordination modes of the distibines and those of Ph2PCH2PPh2 and related ligands. The Royal Society of Chemistry 2000.
- Even, Tina,Genge, Anthony R. J.,Hill, Angela M.,Holmes, Nicholas J.,Levason, William,Webster, Michael
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p. 655 - 662
(2007/10/03)
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