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)A, 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)A, consistent with a metal–metal bond.