164019-82-3Relevant academic research and scientific papers
An unprecedented bending of a bridging diynyl ligand in an unsymmetrical binuclear rhodium(I) complex
Werner, Helmut,Gevert, Olaf,Steinert, Paul,Wolf, Justin
, p. 1786 - 1791 (2008/10/09)
The reaction of [Rh(η2-O2CCH3)(PiPr3) 2] (2) with 2 equiv of phenylbutadiyne leads, in the presence of Na2CO3, to the formation of the five-coordinate bis(diynyl)hydridorhodium(III) complex [RhH(C≡CC≡CPh)2(PiPr3)2] (3). While 3 reacts with pyridine to give the stable octahedral compound [RhH(C≡CC≡CPh)2(py)(PiPr3)2] (4), on treatment with carbon monoxide the square-planar complex trans-[Rh(C≡CC≡CPh)(CO)(PiPr3)2] (6) is formed via the spectroscopically characterized 1:1 adduct 5 as a labile intermediate. Compound 6, which has also been prepared from [Rh(η3-CH2C6H5)(PiPr 3)2] (7), CO, and phenylbutadiyne, reacts with [RhCl(PiPr3)2]n (1) to yield the binuclear complex [Rh(CO)(PiPr3)2(η1,η 2-C≡CC≡CPh)-RhCl(PiPr3)2] (8). The X-ray structural analysis of 8 (triclinic space group P1 (No. 2) with a = 12.460(2) A?, b = 13.954(2) A?, c = 16.431(2) A?, α = 97.98(1)°, β = 91.47(1)°, γ = 109.61-(1)°, V = 2657(1) A?3, and Z = 2) reveals a square-planar coordination around each of the metal centers which are bridged by a strongly bent diynyl ligand. The reaction of 1 with phenylbutadiyne leads, via the isomeric diyne and diynyl hydrido species 9 and 10 as intermediates, to the alkynyl-substituted vinylidenerhodium(I) complex trans-[RhCl-(=C=CHC≡CPh)(PiPr3)2] (11). In the presence of pyridine the diynyl(hydrido)rhodium derivative [RhH(C≡CC≡CPh)Cl(py)(PiPr3)2] (12) is obtained.
