Synthesis and reactions with electrophiles and nucleophiles of the ruthenium(I) complex [Ru2(µ-C10H8N2)(CO)6]. Crystal structure of [Ru2(µ-C10H8N2)(CO)4{P(OPh)3}2](C10H10N2= 1,8-diaminonaphthalene)

Abstract

The ruthenium(I) complex [Ru₂(µ-C₁₀H₈N₂)(CO)₆]1(C₁₀H₁₀N₂= 1,8-diaminonaphthalene) has been prepared by reaction of [Ru₃(CO)₁₂] with an excess of 1,8-diaminonaphthalene under carbon monoxide, at 110 °C. Complex 1 reacts with halogens, tetrafluoroboric acid and dimethyl acetylenedicarboxylate to give the triply bridged complexes [Ru₂(µ-C₁₀H₈N₂)(µ-X)(CO)₆]⁺(X = 1 2, Br 3 or Cl 4)[Ru₂(µ-C₁₀H₈N₂)(µ-H)(CO)₆]BF₄5 and [Ru₂(µ-C₁₀H₈N₂){µ-C₂(CO₂Me)₂}(CO)₆]6, respectively. The complexes [Ru₂(µ-C₁₀H₈N₂)(CO)₄L₂][L = PPhⁱ₃7, PPh₃8, P(OPh)₃9 or dppm-κP12], which contain the introduced ligands trans to the Ru–Ru bond, have been prepared by reaction of 1 with an excess of the appropriate P-donor ligand L. However the reaction of 1 with an excess of trimethyl phosphite renders the trisubstituted compound [Ru₂(µ-C₁₀H₈N₂)(CO)₃{P(OMe)₃}₃]10. The reaction of 1 with one equivalent of bis(diphenylphosphino)methane (dppm), at room temperature, has been found to give a mixture of oligomers containing bridging and monoco-ordinated dppm ligands. These oligomers aggregate in refluxing tetrahydrofuran to give the polymeric compound [{Ru₂(µ-C₁₀H₈N₂)(CO)₄(µ-dppm)}_n]11. The monosubstituted compound [Ru₂(µ-C₁₀H₈N₂)(CO)₅(py)]13 has been prepared by reaction of complex 1 with pyridine (py). Infrared and ¹H and ³¹P-{¹H} NMR spectra of all the compounds are presented and discussed in relation to their structures. The crystal structure of compound 9 has been determined by X-ray diffraction methods. Crystals of 9 are monoclinic, space group P2₁/m, with a= 9.520(4), b= 28.073(8), c= 10.070(5)Å, β= 117.15(2)° and Z= 2. The structure has been solved from diffractometer data by direct and Fourier methods and refined by fullmatrix least squares to R= 0.0658 for 3626 observed reflections. The two Ru atoms are doubly bridged by the nitrogen atoms of the deprotonated 1,8-diaminonaphthalene ligand with a short Ru–Ru separation, 2.571(1)Å, consistent with a metal–metal bond.