Synthesis, crystal structure and solution fluxionality of heterometallic hydride clusters [WRu3L(CO)11(µ-H)2-(AuPPh3)](L = C5H5 or C5Me5)

Abstract

Two heterometallic compounds [WRu₃L(CO)₁₁(µ-H)₂(AuPPh₃)](L = C₅H₅1 or C₅Me₅2) were prepared by hydrogenation of [WRu₃L(CO)₁₂(AuPPh₃)] in refluxing tetrahydrofuran solution. The C₅H₅ derivative possesses a tetrahedral Ru₃W core in which the AuPPh₃ unit bridges a Ru–Ru edge, one hydride caps a nearby WRu₂ face and the second spans a Ru–Ru edge, whereas the corresponding C₅Me₅ derivative adopts a related but distinct molecular geometry in the solid state, in which both hydride ligands span the equivalent Ru–W edges and the AuPPh₃ unit is linked to the Ru atoms supporting the hydrides. The dynamic processes in solution were established for these two derivatives. Crystal data for 1: monoclinic, space group P2₁/c; a= 9.031(2), b= 25.086(4), c= 16.238(3)Å, β= 95.75(2)°, Z= 4; final R= 0.036, R′= 0.032 for 4391 reflections with l > 2σ(l). Crystal data for 2: space group Pna2₁; a= 20.389(3), b= 16.226(3), c= 26.074(4)Å, Z= 8; final R= 0.040, R′= 0.036 for 4556 reflections with l > 2σ(I).