TY - JOUR
T1 - Ligand Substitution Reactions in Metal Cluster Complexes. Evidence for Unusually Facile Metal-Metal Bond Cleavages in the Reactions of Os3(CO)11(NCMe) and Os3(CO)10(NCMe)2 with CNCF3 Including the Isolation and Structural Characterization of Intermediates
AU - Adams, Richard D.
AU - Chi, Yun
AU - DesMarteau, Darryl D.
AU - Lentz, Dieter
AU - Marschall, Robert
AU - Scherrmann, Andreas
PY - 1992/12/1
Y1 - 1992/12/1
N2 - The reaction of Os3(CO)11(NCMe) with an excess of CNCF3 at 25 °C yielded two products Os3(CO)11(μ-CNCF3)2 (1), 35%, and Os3(CO)10(μ-CNCF3)2 (2), 4%. Compound 1 was converted to 2 in 87% yield at 80 °C. Both compounds 1 and 2 were characterized crystallographically. Compound 1 consists of an open triosmium cluster with CNCF3 ligands bridging each of the two metal-metal bonds. Compound 2 consists of a closed triosmium cluster with two CNCF3 ligands bridging the same edge of the cluster. Compound 2 was the principal product obtained from the reaction of Os3(CO)10(NCMe)2 with an excess of CNCF3; however, two additional products Os3(CO)10(NCMe)(μ-CNCF3)2 (3), 17% yield, and Os3(CO)9(NCMe)(μ-CNCF3)2 (4), 2% yield, were also obtained. Compound 3 is structurally analogous to 1 except for the presence of a NCMe ligand coordinated to the central osmium atom. Compound 4 is analogous to 2 except for the presence of a NCMe ligand coordinated to the unique metal atom. When heated to reflux in CH2Cl2, 3 was transformed into a mixture of 2 and 4. Although they can be isolated, compounds 1 and 3 are also intermediates en route to 2 and 4. Their characterization demonstrates the viability of previously proposed cluster-opening ligand addition steps as part of a mechanism of ligand substitution in the reactions of some metal cluster complexes. Crystal data: for 1, space group = Pca21 a = 14.456 (2) Å, b = 11.077 (2) Å, c = 14.301 (4) Å, Z = 4, 1714 reflections, R = 0.029; for 2, space group = Pbcn, a = 26.940 (6) Å, b = 11.361 (3) Å, c = 14.450 (2) Å, Z = 8, 1644 reflections, R = 0.034; for 3, space group = P1, a = 10.390 (3) Å, b = 15.416 (3) Å, c = 8.079 (1) Å, α = 99.16 (2)°, β = 104.61 (2)°, γ = 94.40 (2)°, Z = 2, 2475 reflections, R = 0.024; for 4, space group = P21/n, a = 19.065 (4) Å, b = 13.080 (2) Å, c = 9.418 (2) Å, β = 90.12 (2)°, Z = 4, 2362 reflections, R = 0.036.
AB - The reaction of Os3(CO)11(NCMe) with an excess of CNCF3 at 25 °C yielded two products Os3(CO)11(μ-CNCF3)2 (1), 35%, and Os3(CO)10(μ-CNCF3)2 (2), 4%. Compound 1 was converted to 2 in 87% yield at 80 °C. Both compounds 1 and 2 were characterized crystallographically. Compound 1 consists of an open triosmium cluster with CNCF3 ligands bridging each of the two metal-metal bonds. Compound 2 consists of a closed triosmium cluster with two CNCF3 ligands bridging the same edge of the cluster. Compound 2 was the principal product obtained from the reaction of Os3(CO)10(NCMe)2 with an excess of CNCF3; however, two additional products Os3(CO)10(NCMe)(μ-CNCF3)2 (3), 17% yield, and Os3(CO)9(NCMe)(μ-CNCF3)2 (4), 2% yield, were also obtained. Compound 3 is structurally analogous to 1 except for the presence of a NCMe ligand coordinated to the central osmium atom. Compound 4 is analogous to 2 except for the presence of a NCMe ligand coordinated to the unique metal atom. When heated to reflux in CH2Cl2, 3 was transformed into a mixture of 2 and 4. Although they can be isolated, compounds 1 and 3 are also intermediates en route to 2 and 4. Their characterization demonstrates the viability of previously proposed cluster-opening ligand addition steps as part of a mechanism of ligand substitution in the reactions of some metal cluster complexes. Crystal data: for 1, space group = Pca21 a = 14.456 (2) Å, b = 11.077 (2) Å, c = 14.301 (4) Å, Z = 4, 1714 reflections, R = 0.029; for 2, space group = Pbcn, a = 26.940 (6) Å, b = 11.361 (3) Å, c = 14.450 (2) Å, Z = 8, 1644 reflections, R = 0.034; for 3, space group = P1, a = 10.390 (3) Å, b = 15.416 (3) Å, c = 8.079 (1) Å, α = 99.16 (2)°, β = 104.61 (2)°, γ = 94.40 (2)°, Z = 2, 2475 reflections, R = 0.024; for 4, space group = P21/n, a = 19.065 (4) Å, b = 13.080 (2) Å, c = 9.418 (2) Å, β = 90.12 (2)°, Z = 4, 2362 reflections, R = 0.036.
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U2 - 10.1021/ja00053a018
DO - 10.1021/ja00053a018
M3 - RGC 21 - Publication in refereed journal
SN - 0002-7863
VL - 114
SP - 10822
EP - 10826
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 27
ER -