PREPARATIONS AND STRUCTURES OF 2 POLYNUCLEAR AGGREGATES OBTAINED BY USING THE METALLALIGAND (CLAUPPH2CH2)2ASPH

Treatment of trans-Pd(NCPh)2Cl2 with 2 equiv of (ClAuPPh2CH2)2AsPh produces yellow trans-PdCl2{(ClAuPPh2CH2)2AsPh}2, which crystallizes as a 2.75 dichloromethane solvate in the monoclinic space group P21/n with a = 16.226 (3) Å, b = 17.609 (6) Å, c = 27.780 (6) Å, and β = 102.87 (2)° with Z = 4 at 130 K. Refinement of 3612 reflections with I > 2σ(I) and 334 parameters yields R = 0.110 and Rw = 0.097. The structure consists of a planar trans-PdCl2As2 unit irregularly surrounded by four linear ClAuP units. The Pd⋯Au separations range from 3.358 (6) to 6.389 (6) Å. The electronic absorption spectrum of the complex is similar to that of PdCl2(AsPh3)2; this indicates that the palladium center is electronically unaffected by the presence of its gold neighbors. Reaction of (ClAuPPh2CH2)2AsPh, (Ph2PCH2)2AsPh, and Rh2(CO)4(μ-Cl)2 in dichloromethane followed by the addition of ammonium hexafluorophosphate yields orange [Au2Rh(CO)Cl{μ-(Ph2PCH2)2AsPh}2][PF6]2. This crystallizes as a 0.5 dichloromethane solvate in the triclinic space group [formula omited] with a = 12.217 (3) Å, b = 24.882 (8) Å, c = 26.677 (10) Å, α = 112.83 (3)°, β = 91.19 (3)°, γ = 95.52 (2)°, and Z = 4 at 130 K. Refinement of 8480 reflections with I > 2σ(I) and 738 parameters yielded R = 0.098 and Rw = 0.094. The structure of the cation consists of a planar Rh(CO)ClAs unit surrounded by two, nearly linear P2Au groups with Rh-Au distances of 3.006 (2) and 3.028 (2) Å in one of the two independent cations and 3.034 (2) and 3.074 (2) Å in the other. The electronic absorption spectrum (λmax 464 nm; ϵ 3.8 × 104 M-1 cm-1) indicates that a significant interaction exists between the central rhodium ion and its two gold neighbors. This complex also shows photoluminescence (λmax 620 nm) in dichloromethane solution at 25 °C. © 1990, American Chemical Society. All rights reserved.