DIFFERENT COORDINATION MODES OF 3-HYDROXY-1,2,3-BENZOTRIAZIN-4(3H)-ONE - MOLECULAR-STRUCTURES OF (MU-H)OS-3(CO)(10)(MU(2)-(2,3-ETA(2))-(O)NNNC7H4O) AND (MU-H)RU-3(CO)(10)(MU(2)-(1,2-ETA(2))-NNN(O)C7H4O)

Reaction of Os-3(CO)(10)(NCMe)(2) with 3-hydroxy-1,2,3-benzotriazin-4( 3H)-one (1) in CH2Cl2 gave the N-oxide complex (mu- H)Os-3(CO)(10)(mu( 2)-(2,3-eta(2))-(O)NNNC7H4O) (2). Following similar conditions, Ru-3(C O)(10)(NCMe)(2) reacted with 1 to afford (mu-H)Ru-3(CO)(10) (mu(2)-(1, 2-eta(2))-NNN(O)C7H4O) (3). Results from single-crystal X-ray diffract ion analyses for 2 and 3 revealed that ligand 1 exhibited different co ordination modes towards triosmium and triruthenium clusters. Both str uctures show that the ligand coordinated axially at two metal centres of the triangular clusters. However, ligand 1 is bound to complex 2 in a mu(2)-(2,3-eta(2)-N-O) coordination mode, whereas, it exhibits a mu (2)-(1,2-eta(2)-N-N') coordination mode in 3. Complex 2 crystallized i n the monoclinic space group P2(1)/n with a = 8.159(2) Angstrom, b = 1 9.778(3) Angstrom, c = 13.857(3) Angstrom; beta = 95.862(2)degrees; V = 2224.3(8) Angstrom(3), Z = 4, R = 3.9%, R-w = 4.6%. Complex 3 crysta llized in the triclinic space group P-1(-) with a = 8.496(2) Angstrom, b = 14.523(2) Angstrom, c = 18.445(1) Angstrom; alpha = 85.801(9)degr ees, beta = 83.874(1)degrees,gamma = 78.825(2)degrees; V = 2216.8(7) A ngstrom(3), Z = 4, R = 3.1%, R-w = 3.2%. (C) 1997 Elsevier Science S.A .