Abstract
Reaction of Os 3 (CO) 10 (NCMe) 2 with 3-hydroxy-1,2,3-benzotriazin-4(3H)-one (1) in CH 2 Cl 2 gave the N-oxide complex ( μ-H)Os 3 (CO) 10 ( μ 2 -(2,3-η 2 )-(O)NNNC 7 H 4 O) (2). Following similar conditions, Ru 3 (CO) 10 (NCMe) 2 reacted with 1 to afford ( μ-H)Ru 3 (CO) 10 )( μ 2 -(1,2-η 2 )-NNN(O)C 7 H 4 O) (3). Results from single-crystal X-ray diffraction analyses for 2 and 3 revealed that ligand 1 exhibited different coordination modes towards triosmium and triruthenium clusters. Both structures show that the ligand coordinated axially at two metal centres of the triangular clusters. However, ligand 1 is bound to complex 2 in a μ 2 -(2,3-η 2 -N-O) coordination mode, whereas, it exhibits a μ 2 -(1,2-η 2 -N-N′) coordination mode in 3. Complex 2 crystallized in the monoclinic space group P2 1 /n with a = 8.159(2) Å, b = 19.778(3) Å, c = 13.857(3) Å; β = 95.862(2)°; V = 2224.3(8) Å 3 , Z = 4, R = 3.9%, R w = 4.6%. Complex 3 crystallized in the triclinic space group P - 1 with a = 8.496(2) Å, b = 14.523(2) Å, c = 18.445(1) Å; α = 85.801(9)°, β = 83.874(1)°, γ = 78.825(2)°; V = 2216.8(7) Å 3 , Z = 4, R = 3.1%, R w = 3.2%. © 1997 Elsevier Science S.A.