47829-28-7Relevant academic research and scientific papers
Acid-base chemistry of the methylrhodium(III) derivative CH3RhI2(PPh3)2
Siedle,Newmark,Pignolet
, p. 855 - 859 (2008/10/08)
Reaction of excess methyl iodide with the 14-electron Rh(I) salt (Ph3P)3Rh+HC(SO2CF3) 2- produces green CH3RhI2(PPh3)2, λmax 500 and 610 nm. Crystal data: monoclinic (centric), C2/c, a = 23.982 (5) A?, b = 9.828 (3) A?, c = 16.063 (6) A?, β = 114.73 (3)°, Z = 4, and V = 3439 (4) A?3. The structure, solved by using 2618 reflections for which Fo2 > 1.0 σ(Fo2), converged at R = 0.022 and Rw = 0.034. The coordination geometry of rhodium(III) is flattened square pyramidal with a C2 axis through rhodium and the methyl carbon. The metal is displaced 0.25 A? toward the apical methyl group from the least-squares plane containing two trans iodines and two trans phosphorus atoms, which comprise the base of the pyramid. Important bond distances are d(Rh-C) = 2.06 (1) A?, d(Rh-I) = 2.635 (1) A?, and d(Rh-P) = 2.365 (2) A?. Ch3RhI2(PPh3)2 has an extensive acid-base chemistry. It is converted by excess carbon monoxide to cis- and trans-CH3CORhI2(PPh3)2CO from which reversible dissociation of the terminal carbonyl ligand leads to CH3CORhI2(PPh3)2. This acetylrhodium(III) compound decomposes by reductive elimination of methyl iodide to form (Ph3P)2Rh(LO)I. Trimethylphosphine and trimethyl phosphite displace triphenylphosphine to yield mer-CH3RhI2L3 (L = (CH3O)3P, (CH3)3P). Migratory insertion of sulfur dioxide into the CH3 bond provides CH3SO2RhI2(PPh3)2.
