Transition metal complexes with sulfur ligands. Part CXXVII. Azido, halido and nitrido ruthenium complexes with sulfur-rich coordination spheres

Article abstract of DOI:10.1016/s0020-1693(97)05782-4

Ru(II) and Ru(III) azido complexes were synthesized as potential precursors for dinitrogen complexes with sulfur-dominated coordination spheres. NEt₄[Ru(N₃)(PCy₃)('S₄')] (1) was obtained from the reaction of [Ru(DMSO)(PCy₃)('S₄')] with NEt₄N₃ ('S₄'^2-=1,2-bis(2-mercaptophenylthio)ethane(2-)). The oxidation of [Ru(DMSO)(PR₃)('S₄')] with I2₂ yielded [Ru(I)(PR₃)('S₄')] (R=Cy 2a, ⁱPr2b). The iodo ligand in 2a and 2b could be exchanged for azide and chloride yielding [Ru(N₃)(PR₃)('S₄')] (R=Cy 3a, ⁱPr 3b) and [Ru(Cl)(PCy₃)('S₄')] (4). The azido ligand of 1 could not be transformed into a N₂ ligand, and the reaction of 3a with HBF₄ yielded the nitrido complex [μ-N(Ru(PCy₃)('S₄')}₂](PF ₆)([5]PF₆) via a labile intermediate exhibiting an IR band at 2070 cm^-1 at -40°C. The molecular structures of 2a, 4 and [5]⁺ as the BPh₄^- salt were determined by X-ray structure analysis. Crystal data of (a) 2a·C₇H₈: triclinic space groupP1; a=1087.4(1), b=1089.5(1), c=1988.8(1) pm; α=74.13(1), β=78.66(1), γ=61.22(1)°; Z=2; (b) 4·CH₂Cl₂: triclinic space group P1; a=1088.7(5), b=1065.6(3), c=1778.4(6) pm; α=80.66(2), β=72.10(4), γ=67.52(3)°; Z=2; (c) [5]BPh₄·3THF: orthorhombic space group Pna2₁; a=1972.9(6), b=2606.3(6), c=1831.1(12) pm; Z=4. The metal centers of all three complexes show pseudo-octahedral coordination and exhibit no anomalies in distances and angles. The two Ru centers in [5] (BPh₄)·3THF are linked via a bent nitrido bridge. 1998 Elsevier Science S.A.