J. Wolf et al., SYNTHESIS AND MOLECULAR-STRUCTURE OF 6-COORDINATE DICHLORODIHYDRIDORUTHENIUM(IV) AND 5-COORDINATE VINYLIDENERUTHENIUM(II) COMPLEXES, EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, (11), 1998, pp. 1827-1834
The dichlorodihydridoruthenium(IV) compound [RuH2Cl2-(PiPr(3))(2)] (4)
was prepared from [RuCl2(C8H12)](n) (3), PiPr(3), and H-2 in 2-butano
l via the chlorohydridoruthenium (II) derivative [RuHCl(H-2)(PiPr(3))(
2)] (5) as an intermediate. The synthesis of 5 was achieved under simi
lar conditions from 3, PiPr3, H-2, and 2-butanol in the presence of NE
t3. Compound 4, which was characterized by X-ray crystal structure ana
lysis, reacts with excess phenylacetylene to give the phenylvinylidene
complex [RuCl2(=C=CHPh) (PiPr(3))(2)] (7) and with propargylic alcoho
ls or derivatives thereof to afford the vinylcarbene complexes [RuCl2(
=CHCH=CR2) (PiPr(3))(2)] (9, 10), respectively. From 5 and terminal al
kynes RC=CH the chlorohydridovinylidene compounds [RuHCl(=C=CHR)(PiPr(
3))(2)] (11, 12) were obtained. The phenylvinylidene complex [RuCl2(=C
= CHPh)(PCy3)(2)] (15) was prepared from phenylacetylene and either [R
uH2Cl2(PCy3)(2)] (14) or one of the carbene derivatives [RuCl2(=CHR)(P
Cy3)(2)] (16, 17) as starting materials. The X-ray crystal structure a
nalysis of 15 confirms a distorted square-pyramidal geometry with the
vinylidene ligand in the apical position. The interconversion of 4 to
5 and of the tricyclohexylphosphane counterparts 14 to 13 was achieved
by hydrogen transfer from 2-propanol in the presence of PR3. The reve
rse reaction occurs upon treatment of 5 or 13 with the corresponding p
hosphonium salt [HPR3]Cl or HCl, respectively.