- Addition of phenylacetylene to the mixed-chalcogenide compounds (CO)6Fe2(μ-SeTe), (CO)6Fe2(μ-SSe), and (CO)6Fe2(μ-STe). Structural characterization of (CO)6Fe2{μ-SeC(H)=C(Ph)Te}
-
From the room-temperature reaction of the mixed-chalcogenide compound Fe2(CO)6(μ-SeTe) with phenylacetylene two isomeric products were isolated, Fe2(CO)6{-SeC(H)=C-(Ph)Te} (1) and Fe2(CO)6{μ-SeC(Ph)=C(H)Te} (2). Fe2(CO)6(μ-SSe) reacted with phenylacetylene to form Fe2(CO)6{μ-SC(Ph)=C(H)Se} (3). The room-temperature reaction of Fe2(CO)6(μ-STe) with phenylacetylene also yielded two isomeric products, Fe2(CO)6(μ-SC-(H)=C(Ph)Te) (4) and Fe2(CO)6(μ-SC(Ph)=C(H)Te) (5). In all of these reactions, the homochalcogenide compounds Fe2(CO)6(μ-EC(H)=C(Ph)E) (E = Se, Te, E = S, Se, and E = S, Te, respectively) were also formed in trace amounts. The new compounds 1-5 were characterized by IR and 1H, 13C, 77Se, and 125Te NMR spectroscopy. Compound 1 was structurally characterized by single-crystal X-ray diffraction methods. It crystallized in the triclinic space group P1 with a = 7.773(9) A?, b = 10.635(9) A?, c = 12.010(10) A?, α = 104.99-(10)°, β = 102.86(11)°, γ = 106.38(9)°, V = 872.1(8) A?3, Z = 2, and D(calc) = 2.241 g cm-3. Full-matrix least-squares refinement of 1 converged to R = 0.077 and Rw = 0.086.
- Mathur, Pradeep,Hossain, Md. Munkir,Umbarkar, Shubhangi,Satyanarayana,Tavale, Sudam S.,Puranik, Vedavati G.
-
p. 959 - 963
(2008/10/09)
-
- Cluster synthesis. 24. Synthesis and characterization of new sulfur-containing tungsten-iron carbonyl cluster complexes
-
The reaction of Fe3(CO)9(μ3-S)2 (1) with W(CO)6 under UV irradiation yielded the W(CO)5 adduct, Fe3(CO)9(μ3-S)(μ 4-S)[W(CO)5] (3), formed by the addition of the W(CO)5 group to one of the sulfido ligands in 1. The reaction of 1 with W(CO)5(PMe2Ph) under UV irradiation yielded the related PMe2Ph derivative of 3, Fe3(CO)9(μ3-S)(μ 4-S)[W(CO)4PMe2Ph] (5), but also two new products WFe2(CO)9(PMe2Ph)(μ3-S) 2 (6) and WFe3(CO)11(PMe2Ph)(μ3-S) 2 (7). Compound 7 can be obtained by UV irradiation of 5. Compound 6 can be obtained from 7 in low yield by reaction with CO but was obtained in a better yield (40%) from the reaction of Fe2(CO)6(μ-S2) (2) with W(CO)5(PMe2Ph) in the presence of UV irradiation. This reaction also yielded a W(CO)5 adduct of 6, WFe2(CO)9(PMe2Ph)(μ3-S)(μ 4-S)[W(CO)5] (8), in very low yield, 3%. Compound 8 was obtained in 37% yield from the reaction of 6 with W(CO)6 under UV irradiation. Compounds 5-8 were characterized by X-ray crystallographic methods. For 5: space group Pnma, a = 24.033 (6) A?, b = 14.226 (4) A?, c = 8.715 (4) A?, Z = 4; solved by direct methods with R = 0.028 for 1579 reflections. For 6: space group P21/n, a = 9.129 (1) A?, b = 15.878 (6) A?, c = 16.208 (3) A?, β = 91.52 (1)°, Z = 4; solved by direct methods with R = 0.029 for 2477 reflections. For 7: space group P1 a = 10.751 (2) A?, b = 13.776 (3) A?, c = 9.424 (3) A?, α = 101.55 (2)°, β = 98.67 (2)°, γ = 76.34 (1)°, Z = 2; solved by direct methods with R = 0.024 for 4069 reflections. For 8: space group C2/c, a = 29.91 (1) A?, b = 13.427 (3) A? c = 17.640 (5) A?, β = 120.48 (2)°, Z = 8; solved by direct methods with R = 0.027 for 3418 reflections. The structure of 6 consists of an open WFe2 cluster with two W-Fe bonds and triply bridging sulfido ligands on opposite sides of the cluster. The structure of 7 consists of a butterfly WFe3 cluster with the tungsten atom in a hinge position. Sulfido ligands bridge the two closed Fe2W triangular groups on opposite sides of the cluster. Compounds 5 and 8 are W(CO)4L adducts of 1, L = PMe2Ph, and 6,L = CO, respectively. The transformation of 5 to 7 is evidence that the sulfido ligand plays a key role in the metal-addition and cluster-forming processes. It is also believed that the lower electron density withdrawal capacity of the PMe2Ph ligand compared to that of CO is one feature that promotes the stabilization of the W-Fe bonds observed in 6 and 7.
- Adams, Richard D.,Babin, James E.,Wang, Jin-Guu,Wu, Wengan
-
p. 703 - 709
(2008/10/08)
-