193470-89-2Relevant academic research and scientific papers
Alkyne or alkene binding versus hydrogenation in reactions with [Ir2H(CO)2(μ-H)2(Ph2PCH 2PPh2)2] [BF4]. Structure of [Ir2(C2H4)(CO)2(μ-H)(Ph 2PCH2PPh2)2] [BF4]
Antwi-Nsiah, Fred H.,Torkelson, Jeff R.,Cowie, Martin
, p. 213 - 226 (1997)
The reactions of [Ir2H(CO)2(μ-H)2(dppm)2] [BF4] (1) (dppm = Ph2PCH2PPh2) with the alkynes, dimethyl acetylenedicarboxylate, hexafluoro-2-butyne or acetylene yield the respective products [Ir2(H)2(CO)2(μ-H)(μ-RCCR)(dppm) 2] [BF4] (R = CO2Me, CF3, H) in which the alkyne bridges the metals, bound in a parallel orientation. With tetrafluoroethylene the analogous olefin-bridged product [Ir2(H)2(CO)2(μ-H)(μ-C2F 4)(dppm)2] [BF4] is obtained. The reactions of 1 with diphenylacetylene or ethylene result in hydrogenation, to yield cis-stilbene and ethane, respectively, with subsequent reaction of the resulting unsaturated intermediate with additional substrate to give [Ir2(CO)2(μ-H)(μ-PhCCPh)(dppm)2] [BF4] or [Ir2(C2H4)(CO)2(μ-H)(dppm) 2] [BF4]. In the diphenylacetylene adduct this group is bound in a parallel position bridging the metals whereas the ethylene ligand binds to one metal in a terminal position opposite the Ir-Ir bond. The structure of this ethylene adduct has been determined by X-ray crystallography. This compound crystallizes in the monoclinic space group P21/n, having a = 13.6872(7), b = 15.459(2), c = 23.813(2) A?, β = 97.870(5)° and Z = 4. The carbonyl and ethylene ligands are disordered, but their positions have been adequately resolved and the structure has refined (on F2) to R1(F0) = 0.0344 (observed data) for 8699 unique reflections (6638 observations) and 653 parameters varied.
