´
´
J. A. Cabeza, J. Garcıa-Dıez, and V. Riera
FULL PAPER
(626.31): calcd. C 28.77, H 1.45, N 4.47; found C 28.51, H 1.58, N
perature for 1 h, but no reaction was observed (IR). The solution
4.09. Ϫ IR (CH2Cl2): ν˜ ϭ 2114 cmϪ1 (m), 2051 (s), 1986 (m). Ϫ was then heated to reflux temperature. After 30 min, the IR spec-
13C{1H} NMR (CD2Cl2): δ ϭ 196.9 (2 CO), 190.2 (2 CO), 181.9 trum showed the complete transformation of 5 into the asymmetric
(1 CO), 148.7 (2 C), 135.4 (1 C), 126.1 (2 C), 125.3 (1 C), 124.5 (2 cationic derivative 7b.
C), 114.7 (2 C) (all singlets); the resonances at δ ϭ 181.9, 126.1,
Thermal Isomerization of 7a to 7b: A solution of 7a[BF4] (50
124.5, and 114.7 are split into doublets in the proton-coupled spec-
mg, 0.046 mmol) in 1,2-dichloroethane (20 ml) was stirred at reflux
trum.
temperarure. The reaction was monitored by IR spectroscopy,
[ Ru2( µ-dan) ( µ-H) ( PPh3) 2( CO) 4] [ BF4] (7a[BF4], symmetric
isomer): Solid 2[BF4] (25 mg, 0.041 mmol) was added to a stirred
solution of PPh3 (22 mg, 0.084 mmol) in dichloromethane (10 ml).
The reaction was instantaneous (IR). No changes were observed in
the IR spectrum of this solution after 20 h. The solvent was re-
moved under reduced pressure and the residue was washed with
hexane (2 ϫ 5 ml) and dried to give 7a[BF4] as a yellow solid (36
mg, 80%). Ϫ C50H39BF4N2O4P2Ru2 (1082.79): calcd. C 55.46, H
which showed the complete transformation of 7a into 7b after 10 h.
When the chloride salt 7a[Cl] was used as starting material, under
analogous conditions, the transformation of 7a into 7b took only
30 min.
Acid-Catalysed Isomerization of 7a to 7b: [HOEt2][BF4] (0.2 ml,
60% solution in diethyl ether) was added to a solution of 7a[BF4]
(50 mg, 0.046 mmol) in dichloromethane (20 ml). The IR spectrum
of the resulting solution showed the complete transformation of 7a
into 7b.
3.63, N 2.59; found C 54.92, H 3.94, N 2.30. Ϫ IR (CH Cl ): ν ϭ
˜
2
2
2063 cmϪ1 (s), 2047 (m), 1998 (s).
[ Ru2( µ-dan) ( µ-H) ( PPh3) 2( CO) 4] [ BF4] (7b[BF4], asymmetric
isomer): An excess of [HOEt2][BF4] (0.2 ml, 60% solution in diethyl
ether) was added to a solution of complex 6 (100 mg, 0.100 mmol)
in dichloromethane (10 ml). The reaction was instantaneous (IR).-
The solvent was removed under reduced pressure and the oily resi-
due was washed with diethyl ether (3 ϫ 5 ml) and dried to give
7b[BF4] as a yellow solid (87 mg, 80%). Ϫ C50H39BF4N2O4P2Ru2
(1082.79): calcd. C 55.46, H 3.63, N 2.59; found C 55.42, H 3.83,
[1]
[2]
[1a]
For reviews on late-transition-metal amido complexes, see:
M. D. Fryzuk, C. D. Montgomery, Coord. Chem. Rev. 1989, 95,
1Ϫ40. Ϫ [1b] H. E. Bryndza, Chem. Rev. 1988, 88, 1163Ϫ1188.
For a review on binuclear ruthenium(I) complexes containing
´
N-donor ligands, see: J. A. Cabeza, J. M. Fernandez-Colinas,
Coord. Chem. Rev. 1993, 126, 319Ϫ336.
[3]
[4]
J. A. Cabeza, V. Riera, M. A. Pellinghelli, A. Tiripicchio, J.
Organomet. Chem. 1989, 376, C23-C25.
´
J. A. Cabeza, J. M. Fernandez-Colinas, V. Riera, M. A. Pel-
N 2.39. Ϫ IR (CH Cl ): ν ϭ 2063 cmϪ1 (m), 2051 (s), 2000 (s). Ϫ
linghelli, A. Tiripicchio, J. Chem. Soc., Dalton Trans. 1991,
371Ϫ377.
˜
2
2
13C{1H} NMR (CDCl3): δ ϭ 196.5 (d, J ϭ 11.1 Hz, 1 CO), 196.4
(d, J ϭ 12.6 Hz, 1 CO), 194.7 (d, J ϭ 12.9 Hz, 1 CO), 190.4 (t,
J ϭ 10.9 Hz, 1 CO), 150.3 (1 C), 147.4 (1 C), 135Ϫ112 (complex
mixture of signals).
[5]
´
J. A. Cabeza, J. M. Fernandez-Colinas, unpublished results.
[6] [6a]
´
J. A. Cabeza, I. del Rıo, V. Riera, F. Grepioni, Organometal-
[6b]
´
J. A. Cabeza, I. del Rıo, V.
lics 1995, 14, 3124Ϫ3126. Ϫ
Riera, F. Grepioni, Organometallics 1997, 16, 812Ϫ815. Ϫ [6c] J.
´
´
A. Cabeza, I. del Rıo, V. Riera, S. Garcıa-Granda, S. B. Sanni,
Protonation of Complex 6 in the Presence of Triphenylphosphane:
An excess of [HOEt2][BF4] (0.2 ml, 60% solution in diethyl ether)
was added to a solution of PPh3 (105 mg, 0.400 mmol) and com-
plex 6 (100 mg, 0.100 mmol) in dichloromethane (10 ml). After 3
min, the IR spectrum of the resulting solution showed only the
presence of the symmetric complex 7a, remaining unchanged after
12 h. The solvent was removed under reduced pressure and the
residue was washed with diethyl ether (3 ϫ 5 ml) and dried to give
pure 7a[BF4] (IR, 31P NMR) (75 mg, 69%).
Organometallics 1997, 16, 1743Ϫ1748.
[7]
[7a] P. L. Andreu, J. A. Cabeza, V. Riera, C. Bois, Y. Jeannin, J.
[7b]
Chem. Soc., Dalton Trans. 1990, 3347Ϫ3353. Ϫ
P. L. An-
dreu, J. A. Cabeza, M. A. Pellinghelli, V. Riera, A. Tiripicchio,
[7c]
Inorg. Chem. 1991, 30, 4611Ϫ4616. Ϫ
P. L. Andreu, J. A.
´
Cabeza, J. L. Cuyas, V. Riera, J. Organomet. Chem. 1992, 427,
[7d]
363Ϫ368. Ϫ
P. L. Andreu, J. A. Cabeza, V. Riera, Inorg.
Chim. Acta 1991, 186, 225Ϫ230.
[8]
[9]
[8a]
See, for example:
G. Lavigne, H. D. Kaesz, J. Am. Chem.
Soc. 1984, 106, 4647Ϫ4648. Ϫ [8b] N. Lugan, G. Lavigne, J. M.
Soulie, S. Fabre, P. Kalck, J. Y. Saillard, J. F. Halet, Organomet-
allics 1995, 14, 1712Ϫ1731 and references therein.
Reaction of Complex 3 with Triphenylphosphane: A solution of
complex 3 (100 mg, 0.187 mmol) and triphenylphosphane (98 mg,
0.375 mmol) in 1,2-dichloroethane (10 ml) was stirred at room tem-
perature for 6 h, when the IR spectrum of the solution showed the
complete transformation of 3 into the symmetric cationic deriva-
tive 7a.
See, for example: [9a] S. H. Han, G. L. Geoffroy, B. D. Dombek,
[9b]
A. L. Rheingold, Inorg. Chem. 1988, 27, 4355Ϫ4361. Ϫ
T.
Chin-Choy, W. T. Harrison, G. D. Stucky, N. Keder, P. C. Ford,
Inorg. Chem. 1989, 28, 2028Ϫ2029 and references therein.
[10]
[11]
[12]
´
J. A. Cabeza, F. J. Lahoz, A. Martın, Organometallics 1992,
11, 2754Ϫ2756.
A. J. Deeming, N. P. Randle, M. B. Hursthouse, R. L. Short, J.
Chem. Soc., Dalton Trans. 1987, 2473Ϫ2477.
C. E. Ash, M. Y. Darensbourg, M. B. Dahl, J. Am. Chem. Soc.
1987, 109, 4173Ϫ4180.
Reaction of Complex 5 with Triphenylphosphane: A solution of
complex 5 (35 mg, 0.056 mmol) and triphenylphosphane (30 mg,
0.113 mmol) in 1,2-dichloroethane (10 ml) was stirred at room tem-
[98118]
1732
Eur. J. Inorg. Chem. 1998, 1729Ϫ1732