187601-99-6Relevant academic research and scientific papers
Methyl(hydrido)platinum(IV) complexes: X-ray structure of the first (μ-hydrido)diplatinum(IV) complex
Hill, Geoffrey S.,Vittal, Jagadese J.,Puddephatt, Richard J.
, p. 1209 - 1217 (2008/10/08)
The complex fac-[PtMe3(SO3CF3)(bu2bpy)] (1) (bu2bpy = 4,4′-di-tert-butyl-2,2′-bipyridine) reacts with NaBH4 to give [Pt2(μ-H)Me6(bu2bpy)2]SO 3CF3 (2), which is the first example of a (μ-hydrido)diplatinum(IV) complex. Complex 2 was fully characterized on the basis of microanalytical, 1H and 195Pt NMR spectroscopic, and X-ray crystallographic data. The reaction of 1 with a large excess of NaBH4 results in the formation of an equilibrium mixture of 2 and fac-[PtHMe3(bu2bpy)] (3). Complex 3 was characterized by 1H NMR spectroscopy in solution but could not be isolated in pure form due to the ease of reversion to 2. Both complexes 2 and 3, which have no ligand than can easily dissociate, are thermally stable to reductive elimination of methane (both in solution and, in the case of complex 2, in the solid state) and to isotopic exchange within Pt(D)CH3 groups, thus giving strong support to the theory that both reactions must occur from within a five-coordinate intermediate. Complex 2 reacts slowly with HX (HX = HCl, HO2CCF3, HSC6H5, NH4+) to give either 2 equiv of fac-[PtClMe3(bu2bpy)] (4), fac- [PtMe3(O2CCF3)(bu2bpy)](5), and fac-[PtMe3(NH3)(bu2bpy)]-SO3CF 3 (6) or 1 equiv of [Pt2(μ-SC6H5)Me6(bu 2bpy)2]SO3CF3 (7), respectively. Qualitatively, the relative rates of these reactions follow the order of acid strength, i.e. HCl ≈ HO2CCF3 ? HSC6H5, indicating that the rate-determining step involves electrophilic attack of H+ on 2. Complex 2 reacts very slowly with nucleophiles such as PPh3 to give 1 equiv of fac-[PtMe3(PPh3)(bu2bpy)]SO3CF 3 (8) and 1 equiv of 3. The reaction of CCl4 with 2 gives fac-[PtClMe3(bu2bpy)] (4), [PtCl2Me2(bu2bpy)] (11), and mer-[PtCl3Me(bu2bpy)] (12) in a 1.0:0.8: 0.2 product ratio but without formation of chloroform.
