A Linear RN₂-Transition Metal Linkage. The Structure of Ru(H₂)(N₂)(B₁₀H₈)S(CH₃)(P(C₆H₅)₃)₃.3C₆H₆

The structure of RuH₂(N₂B₁₀H₈S(CH₃)₂)(P(C₆H₅)₃)₃·3C₆H₆ has been determined crystallographically and consists of discrete molecules of the diazo complex and solvent. The complex crystallizes from benzene-methanol in the triclinic space group C_i¹-P1 with two formula units in a unit cell of dimensions a = 23.80 (1) Å, b = 12.683 (6) Å, c = 12.793 (6) Å, α = 105.63 (2)°, β = 99.16 (2)°, γ = 101.00 (3)°, ρ_exptl= 1.25 (3) g/cm³, and ρ_calcd = 1.242 g/cm³. The structure was solved by Patterson methods. Least-squares refinement has led to a final value of the conventional R index for F_o²> 3σ(F_o²) of 0.072 based on 5590 reflections. This complex of Ru(II) possesses pseudooctahedral geometry with cis hydride ligands and meridinal phosphine ligands. The diazo group N₂B₁₀H₈S(CH₃)₂ is trans to H(1): H(1)-Ru-N(1) = 173(2)°. The RuNNB segment is essentially linear: Ru-N(1)-N(2) = 175.9 (6)° and N(1)-N(2)-B(1) = 172.7 (8)°. This is the first reported example of a transition metal-diazo complex containing the totally linear MNNR linkage. The boron cage possesses regular bicapped Archimedean antiprism geometry; the B-B distances within the square plane are 1.83-1.87 Å with B-B-B-bond angles of approximately 90°. The B-B′ distances of bridging boron atoms range from 1.76 to 1.81 Å with B-B′-B angles of approximately 60°. Some important distances are Ru-N(1) = 1.889 (8), N(1)-N(2) = 1.115 (8), and N(2)-B(1) = 1.50 (1) Å.