M.I. Bruce et al. / Journal of Organometallic Chemistry 693 (2008) 1400–1404
1403
The relatively low yield of 3 precludes any more than
speculation on its possible mode of formation. Ready
exchange of phenylethynyl for chloride, followed by coor-
dination of Cu to the Ru–C„CPh fragment, has been
reported earlier [9] and the lability of the ligands on an
RuL2Cp* centre resulting from steric interactions is well-
known. The isolation of the carbonyl complex
Ru(C„CPh)(CO)(PPh3)Cp* suggests that interaction of
an ethynyl-ruthenium intermediate with adventitious water
(to give a hydroxyvinylidene and hence carbonyl and benz-
aldehyde) or oxygen (or both) has occurred. Consequently,
it is reasonable to suggest that interaction of RuCl-
(PPh3)2Cp* with {CuCCPh}n initially gives Ru(C„
CPh)(PPh3)2Cp*, which interacts further with a second
CuCCPh moiety to give the bis-alkynyl complex
Ru(C„CPh)2(PPh3)Cp* A (Scheme 1), possibly retaining
an interaction with Cu. Intramolecular coupling to give
ruthenacyclopentadiene B, followed by insertion of a third
phenylethynyl group to give a ruthenacyclohexadiene C,
has some precedent in the recently proposed mechanism
for formation of a binuclear substituted cyclopentadienyl-
osmium complex, which incorporates six phenylethynyl
groups [16], although in the present case, insertion into
an Ru–C bond, followed by displacement and ring-closure
to the g-cyclopentadienyl ligand shown in C, occurs. The
formation of Ru complexes containing bulky Cp ligands
formed directly from solvated RuCl3 and HC„CBut has
also been described recently [17]. This could be followed
by attack of a second molecule of A at Cb of one of the
phenylethynyl groups to give the substituted vinylidene,
again interacting with one of the two Cu atoms present
in 3. The second Cu atom retains one of the Cl ligands dis-
placed by phenylethynyl, the second possibly being trapped
together with the displaced PPh3 ligand(s) as a CuCl(PPh3)
complex.
NMR (d6-acetone): d 1.26 [s(br), 15H, Cp*], 1.47 [s(br),
15H, Cp*], 2.65 (s, 1H), 3.88 (s, 1H), 6.88–7.75 (m, 40H,
Ph). 31P NMR (d6-acetone): d 50.9 [s(br), PPh3]. ES-MS
(positive ion mode, MeOH + MeCN, m/z): 1411
[M+MeCNꢀCl]+; 1370 [MꢀCl]+. Crystals for the X-ray
study were obtained from acetone.
3.1. Structure determinations
Full spheres of diffraction data were measured at ca
100 K using a CCD area-detector instrument. Ntot reflec-
tions were merged to N unique (Rint cited) after ‘‘empiri-
cal”/multiscan
absorption
correction
(proprietary
software), No with F > 4r(F) being considered ‘‘observed”.
All data were measured using monochromatic Mo Ka radi-
3
˚
ation, k = 0.7107 A . Anisotropic displacement parameter
forms were refined for the non-hydrogen atoms, (x, y, z,
Uiso H following a riding model. Neutral atom complex
)
scattering factors were used; computation used the SHEL-
XL97 program system [21]. Pertinent results are given below
and in the figure (which shows non-hydrogen atoms with
50% probability amplitude displacement ellipsoids and
˚
hydrogen atoms with arbitrary radii of 0.1 A) and in the
caption thereto.
3 Ru2Cu2(C2Ph){C5H2Ph2(CHPhCPh@C)}(Cl)(PPh3)-
Cp*2 ꢁ 2.5Me2CO ꢁ 0.5H2O ꢂ C78H72ClCu2PRu2 ꢁ 2.5C3H6O ꢁ
0.5H2O, MW = 1559.29. Monoclinic, space group P21/c,
˚
˚
˚
a = 15.4970(5) A, b = 16.4088(9) A, c = 28.1825(6) A,
3
˚
b = 94.418(2)°, V = 7145 A , Z = 4. 2hmax = 63. Dc =
1.448 g cmꢀ3, l = 1.11 mmꢀ1, ‘T’min/max = 0.96. Crystal
0.25 ꢃ 0.18 ꢃ 0.16 mm. Ntot = 75496, N = 22735 (Rint
=
0.028), No = 15123, R1 = 0.037, wR2 = 0.096.
The recorded polymorph of Ru(C„CPh) (CO)-
(PPh3)Cp* [22] is monoclinic, P21/n, Z = 4 (as also is the
˚
˚
present), a = 8.7254(2) A, b = 17.8548(2) A, c = 19.5265
3
˚
˚
(5) A, b = 98.9732(3)°, V = 3005 A (223 K). For the pres-
ent form (C37H35OPRu, M = 627.7), a = 10.5262(7) A,
˚
3. Experimental
˚
˚
b = 10.7300(10) A, c = 26.921(3) A, b = 98.495(7)°,
3
General experimental details have been described else-
where [18]. The complexes RuCl(PPh3)2Cp* [19] and
{Cu(CCPh)}n [20] were obtained as previously described.
A mixture of RuCl(PPh3)2Cp* (108 mg, 0.136 mmol)
and {Cu(CCPh)}n (112.2 mg, 0.68 mmol) was heated in
refluxing benzene (20 ml) for 4.5 h. the liquid turning dark
brown, with some precipitate present. This was filtered off
to give a dark green solid (not further characterised), while
the filtrate was evaporated and separated by preparative
t.l.c. (silica gel, acetone–hexane, 1/4). A broad yellow band
(Rf = 0, 45) contained Ru(C„CPh)(CO)(PPh3)Cp*
(34 mg, 14%), obtained as pale yellow crystals of a previ-
ously unidentified polymorph (from CH2Cl2/hexane), iden-
tified by XRD (see below). The second orange band
(Rf = 0.29) afforded orange-red crystals of 3 (8.1 mg,
8.5%). Anal. Calc. for C78H72ClCu2PRu2: C, 66.66; H,
5.17; M, 1406. Found: C, 66.70; H, 5.12%. IR (CH2Cl2,
cmꢀ1): m(C„C) 2014w; other bands at 1720m, 1673w,
V = 3007 A
(100 K), Dc = 1.386 g cmꢀ3
,
lMo = 0.60
˚
mmꢀ1
;
specimen: 0.33 ꢃ 0.12 ꢃ 0.11 mm; ‘T’min/max
=
=
0.93. 2hmax = 68°; Ntot = 58518, N = 11681 (Rint
0.031), No = 8839; R1 = 0.032, wR2 = 0.081. In the present
[cf. previous] Ru–P, C(O), C are 2.3113(4) [2.3144(10)],
˚
1.852(2) [1.850(4)], 2.020(2) [2.030(5)] A.
4. Supplementary material
CCDC 656852 and 656898 contain the supplementary
crystallographic data for this paper. These data can be
obtained free of charge from The Cambridge Crystallo-
Acknowledgements
We thank Professor Brian Nicholson (University of
Waikato, Hamilton, New Zealand) for providing the mass
1
1600s, 1483m, 1451m, 1378m, 1178w, 1094m, 1071m. H
Bruce, Michael I.
