103190-55-2Relevant academic research and scientific papers
Systematic mixed-metal cluster synthesis. The preparation, structure, and spectroscopic properties of bis((diphenylphosphino)methyl)phenylarsine-bridged complexes containing nearly linear Rh3, RhIrRh, IrRhIr, and Ir3 chains
Balch, Alan L.,Alan Fossett,Olmstead, Marilyn M.,Reedy Jr., Philip E.
, p. 1929 - 1937 (2008/10/08)
Because metal ions prefer binding phosphorus rather than arsenic, reaction between bis((diphenylphosphino)methyl)phenylarsine (dpma) and Rh2(CO)4(μ-Cl)2 or Ir(CO)2Cl(p-toluidine) yields the 12-membered metallocycles Rh2(μ-dpma)2(CO)2Cl2 (1) or Ir2(μ-dpma)2(CO)2Cl2 (2) with uncoordinated arsenic atoms. Trinuclear complexes have been prepared by the addition of a metal ion to the central cavity of these metallocycles. For example, 1 reacts with Ir(CO)2Cl(p-toluidine) in the presence of NaBPh4 to yield [Rh2Ir(μ-dpma)2(CO)3(μ-Cl)Cl][BPh 4] with the RhIrRh sequence, and 2 reacts with Rh2(μ-Cl)2(CO)4 and NaBPh4 to form [Ir2Rh(μ-dpma)2(μ-CO)2(CO) 2(μ-Cl)Cl][BPh4] with an IrRhIr chain. Infrared, electronic, and 31P and 13C NMR spectra of the complexes are reported. The NMR results show that the mixed-metal chains retain their identity under normal handling in solution at room temperature. [Rh2Ir{μ-(C6H5)2PCH 2As(C6H5)CH2P(C6H 5)2}2(CO)3(μ-Cl)Cl][C(C 6H5)4]·2.5CH2Cl2 crystallizes from dichloromethane/ethyl ether in the triclinic space group P1 (No. 2) with a = 12.618 (2) A?, b = 17.057 (5) A?, c = 22.545 (2) A?, α = 85.23 (2)°, β = 79.73 (2)°, and γ = 77.38 (2)° at 140 K. Least-squares refinement of 526 parameters using 7036 reflections yields R = 0.071 and Rw = 0.079. The complex consists of the RhIrRh chain bridged by trans-aligned dpma units. The carbonyl groups are all terminal, one bound to each metal. One chloride bridges one RhIr unit, and the other is a terminal ligand on the other rhodium. The nonbonded Rh?Ir separations are 3.154 (1) and 3.188 (1) A?, and the Rh-Ir-Rh angle is 156.3 (1)°. The electronic absorption spectra of this and related tricarbonyl complexes are analyzed in terms of a dz2 → pz transition.
