Abstract
Reaction of Os 3 (CO) 10 (NCMe) 2 (1) with 1-hydroxybenzotriazole (2) gave the hydrido complex (μ-H)Os 3 (CO) 10 (μ 2 -(2,3-ƞ 2 )-NNN(O)C 6 H 4 ) (3) in 60% yield; reaction of isocyanide complexes Os 3 (CO) 10 (CNR)(NCMe) (4: R = n-Pr, CH 2 Ph) with 2 gave the bridging aminocarbyne products Os 3 (CO) 10 (μ 2 -(2,3-ƞ 2 )-NNN(O)C 6 H 4 )(μ 2 -ƞ 1 -C═NHR) (5 and 6). The O-H bond of the hydroxybenzotriazole ligand was cleaved in these reactions to afford complexes 3, 5, and 6, which contained an Af-oxide moiety. Complexes 5a and 6a as well as 5b and 6b were regioisomers because of the restricted rotation about the C═N double bond in the bridging aminocarbyne. These isomers exhibited different polarities and were separated by chromatography. Results from single-crystal X-ray diffraction analyses for 3, 5a, and 6b revealed the following data. 3: P2 1 /c; a = 8.629(1) Å, b = 9.919(1) Å, c = 25.446(2) Å, β = 95.447(9)°, V = 2168.1(3) Å 3 , Z = 4, R = 2.7%, R w = 3.0%. 5a: P2 1 /c; a = 10.4824(6) Å, b = 15.765(2) Å, c = 16.001(3) Å; β = 97.981(9)°, V = 2618.6(6) Å 3 , Z = 4, R = 3.0%, R w = 3.7%. 6b: P2 1 /c; a = 9.997(2) Å, b = 23.639(4) Å, c = 12.636(2) Å; β = 111.37(1)°, V = 2780.8(8) Å 3 , Z = 4, R = 2.9%, R w = 3.1%. Studies on the structures of 5a and 6b by X-ray methods provided the first evidence indicating the existence of regioisomers with different orientations of the coordinated aminocarbyne group. © 1994, American Chemical Society. All rights reserved.