Synthesis and characterization of 1,1′-diphospharuthenocenes

Article abstract of DOI:10.1021/om020189i

Reaction of [RuCl₂(cod)]_n (cod = 1,5-cyclooctadiene) with lithium 2,5-dialkylphospholide or 1-stannyl-2,5-dialkylphosphole gives Ru(η⁵-PC₄H₂-2,5-R₂)₂ (R = (-)-menthyl, 4a; or cyclohexyl, 4b). Steric bulkiness of the R groups is a crucial factor for the successful preparation of the 1,1′-diphospharuthenocenes. The structure of the complex 4b was studied by X-ray single-crystal structure determination, which clarified the distance between the nearly planar η⁵-phospholyl ligand and the ruthenium center in the complex, being 1.811 A?.

Full text of DOI:10.1021/om020189i

3062
Organometallics 2002, 21, 3062-3065
Syn th esis a n d Ch a r a cter iza tion of
1,1′-Dip h osp h a r u th en ocen es
Masamichi Ogasawara,* Takashi Nagano, Kazuhiro Yoshida, and
Tamio Hayashi*
Department of Chemistry, Graduate School of Science, Kyoto University,
Sakyo, Kyoto 606-8502, J apan
Received March 7, 2002
Summary: Reaction of [RuCl2(cod)]n (cod ) 1,5-cyclooc-
tadiene) with lithium 2,5-dialkylphospholide or 1-stan-
nyl-2,5-dialkylphosphole gives Ru(η5-PC4H2-2,5-R2)2 (R
) (-)-menthyl, 4a ; or cyclohexyl, 4b). Steric bulkiness
of the R groups is a crucial factor for the successful
preparation of the 1,1′-diphospharuthenocenes. The struc-
ture of the complex 4b was studied by X-ray single-
crystal structure determination, which clarified the
distance between the nearly planar η5-phospholyl ligand
and the ruthenium center in the complex, being 1.811
Å.
thenocenes Ru(η5-PC4H2-2,5-R2)2 (R ) (-)-menthyl, 4a ;
R ) cyclohexyl, 4b), which are the first examples of
homoleptic phospholyl-Ru(II) complexes. The single-
crystal X-ray diffraction study of 4b clarified the mo-
lecular structure of the diphospharuthenocene.
In tr od u ction
Phospholyl (phosphacyclopentadienyl) anions show a
variety of coordination modes and are interesting sub-
jects for coordination chemistry.1 Since Mathey’s first
discovery of monophosphaferrocene in 19772 and 1,1′-
diphosphaferrocene in 1978,3 many (η5-phospholyl)iron-
(II) complexes have been prepared and they have
provided rich and diverse chemistry in this field.1,4 On
the other hand, investigations on (η5-phospholyl)ruthe-
nium(II) complexes, heavier homologues of the phos-
phaferrocenes, have received little attention. The first
report on this class of compounds, (η5-C5Me5)Ru(η5-
PC4H2-2,5-tBu2) (1), appeared in 1994.5 More recently,
a (η5-PC4Me4)Ru(II) moiety was reported as substruc-
tures in a cationic triple-decker iron(II)-ruthenium(II)
complex (2)6 and half-sandwich complexes (3).7 Several
(η5-polyphosphacyclopentadienyl)ruthenium(II) species
have been reported as well.8,9 Here we wish to report
the synthesis and characterization of 1,1′-diphospharu-
Resu lts a n d Discu ssion
The reaction of [RuCl2(cod)]n and lithium 2,5-di((-)-
menthyl)phospholide (6a ; 2 equiv to Ru) in THF led to
the formation of a pale yellow 1,1′-diphospharuthenocene
Ru[η5-PC4H2-2,5-((-)-menthyl)2]2 (4a ) in 69% yield
(Scheme 1, method A). The phosholide 6a was generated
from a corresponding 1-phenylphoshole 5a 10 by treat-
ment with 2 equiv of lithium metal, and co-generated
phenyllithium was selectively quenched with anhydrous
11
(1) (a) Mathey, F.; Fischer, J .; Nelson, J . H. Struct. Bonding 1983,
55, 153. (b) Mathey, F. New J . Chem. 1987, 11, 585. (c) Mathey, F. J .
Organomet. Chem. 1990, 400, 149. (d) Mathey, F. Coord. Chem. Rev.
1994, 137, 1.
AlCl3 prior to the reaction with [RuCl2(cod)]n. It was
found that 1-tributylstannyl-2,5-di((-)-menthyl)phos-
phole 7a was also effective as a phospholyl transfer
reagent for the synthesis of 4a (Scheme 1, method B).
The stannylphosphole 7a was readily prepared in situ
according to a sequence illustrated in Scheme 112 and
used for the diphospharuthenocene synthesis without
(2) (a) Mathey, F.; Mitschler, A.; Weiss, R. J . Am. Chem. Soc. 1977,
99, 3537. (b) Mathey, F. J . Organomet. Chem. 1977, 139, 77.
(3) (a) de Lauzon, G.; Mathey, F.; Simalty, M. J . Organomet. Chem.
1978, 156, C33. (b) de Lauzon, G.; Deschamps, B.; Fischer, J .; Mathey,
F.; Mitschler, A. J . Am. Chem. Soc. 1980, 102, 994. (c) de Lauzon, G.;
Deschamps, B.; Mathey, F. Nouv. J . Chim. 1980, 4, 683.
(4) For the recent application of phosphaferrocenes to organic
synthesis, see: (a) Ganter, C.; Kaulen, C.; Englert, U. Organometallics
1999, 18, 5444. (b) Shintani, R.; Lo, M. M.-C.; Fu, G. C. Org. Lett. 2000,
2, 3695. (c) Tanaka, K.; Qiao, S.; Tobisu, M.; Lo, M. M.-C.; Fu, G. C. J .
Am. Chem. Soc. 2000, 122, 9870. (d) Sava, X.; Ricard, L.; Mathey, F.;
Le Floch, P. Organometallics 2000, 19, 4899. (e) Ogasawara, M.;
Yoshida, K.; Hayashi, T. Organometallics 2001, 20, 3913.
(5) Carmichael, D.; Ricard, L.; Mathey, F. J . Chem. Soc., Chem.
Commun. 1994, 1167.
(8) (a) Scherer, O. J .; Bru¨ck, T.; Wolmersha¨user, G. Chem. Ber. 1988,
121, 927. (b) Hitchcock, P. B.; Matos, R. M.; Nixon, J . F. J . Organomet.
Chem. 1993, 462, 319. (c) Hitchcock, P. B.; Nixon, J . F.; Matos, R. M.
J . Organomet. Chem. 1995, 490, 155. (d) Rink, B.; Scherer, O. J .;
Wolmersha¨user, G. Chem. Ber. 1995, 128, 71. (e) Hitchcock, P. B.;
J ohnson, J . A.; Nixon, J . F. Organometallics 1995, 14, 4382.
(9) Diphosphastibolyl-Ru(II) complexes are also known. See: (a)
Francis, M. D.; Hibbs, D. E.; Hursthouse, M. B.; J ones, C.; Malik, K.
M. A. Chem. Commun. 1996, 1591. (b) Black, S. J .; Francis, M. D.;
J ones, C. J . Chem. Soc., Dalton Trans. 1997, 2183.
(6) (a) Herberich, G. E.; Ganter, B. Organometallics 1997, 16, 522.
(b) Herberich, G. E.; Ganter, B.; Englert, U. Struct. Chem. 1998, 9,
359.
(7) Desmurs, P.; Dormond, A.; Nief, F.; Baudry, D. Bull. Soc. Chim.
Fr. 1997, 134, 683.
(10) Ogasawara, M.; Yoshida, K.; Hayashi, T. Organometallics 2001,
20, 1014.
(11) Mathey, F.; de Lauzon, G. Organomet. Synth. 1986, 3, 259.
10.1021/om020189i CCC: $22.00 © 2002 American Chemical Society
Publication on Web 06/08/2002

Notes
Organometallics, Vol. 21, No. 14, 2002 3063
Sch em e 1
n
separating from co-generated Bu3SnPh. Treatment of
[RuCl2(cod)]n with 7a (2 equiv to Ru) in ethanol gave
4a in 79% yield.13 The diphospharuthenocene 4a was
isolated as a moderately air-sensitive, poorly crystalline
solid by silica gel chromatography. The complex is
thermally stable and further purified by sublimation
under high vacuum.
The present synthetic methods of 1,1′-diphospharu-
thenocene are highly sensitive to steric characteristics
of the phospholyl-transfer reagents 6 and 7. While both
methods afford the diphospharuthenocene 4a in good
yields, the corresponding cyclohexyl analogue 4b was
obtained in a reasonable yield only by method A. The
yields of 4b by methods A and B are 71% and 4%,
respectively. Because (-)-menthyl and cyclohexyl groups
possess similar electronic characteristics, the present
results should be attributed to a difference in the steric
nature between the two. The complex 4b was isolated
as a thermally stable pale yellow solid by silica gel
chromatography followed by vacuum sublimation, and
thus the low yield by method B cannot be accounted for
by instability of 4b. Attempts to prepare analogous
diphospharuthenocenes using sterically more compact
phospholes, such as 5c or 5d , were unsuccessful.5
Apparently, steric protection of the nucleophilic phos-
phorus atoms in 6 and 7 was the key to success in the
preparation of 4. The present results suggest that the
two (-)-menthyl groups in 6a /7a are highly effective in
shielding the phosphorus lone pair.
F igu r e 1. Figure 1. ORTEP drawing of 4b with 50%
thermal ellipsoids. All hydrogen atoms are omitted for
clarity. Selected bond lengths (Å) and angles (deg): P(1)-
C(1) ) 1.786(2), P(1)-C(4) ) 1.789(2), C(1)-C(2) ) 1.416-
(2), C(2)-C(3) ) 1.424(2), C(3)-C(4) ) 1.416(2), Ru(1)-
phopsholyl ) 1.811(2); C(1)-P(1)-C(4) ) 90.37(8), P(1)-
C(1)-C(2) ) 111.7(1), C(1)-C(2)-C(3) ) 113.2(1), C(2)-
C(3)-C(4) ) 113.1(1), P(1)-C(4)-C(3) ) 111.6(1).
Hz) and 89.7 (J PC ) 3.6 Hz). These chemical shifts and
coupling constants are comparable to those reported for
the monophospharuthenocene 1.5
The complex 4b was characterized by X-ray crystal
structure analysis, which confirmed the η5-coordination
of the phospholyl ligand to the ruthenium center (Figure
1). For structural comparison, the homologous diphos-
phaferrocene Fe(η5-2,5-Cy-phospholyl)2 (8) was prepared
and the structure was also determined by X-ray analysis
(Figure 2). The complexes 4b and 8 are nearly isostruc-
tural, and the ruthenium in 4b and the iron in 8 are
located at the center of symmetry. No intermolecular
interaction was detected for both 4b and 8. In each
complex, the two phospholyl rings are parallel and
attain a staggered conformation. The nearly planar
phospholyl ligands are slightly distorted, and the phos-
phorus atom lies out of the C(1)-C(2)-C(3)-C(4) plane
by 0.035 Å in 4b and 0.029 Å in 8 away from the central
metal. The distance between a least-squares plane of
the phospholyl ligand and the metal center is 1.811(2)
Å in 4b and 1.671(3) Å in 8. The distance in 4b is about
8% longer than that in 8, which can be attributed to
The NMR data of 4a are consistent with coordination
of the phospholyl ligand in an η5-fashion in the complex.
The C2-symmetry of the free phospholyl, which has the
chiral (-)-menthyl substituents, is broken by the η5-
coordination to the ruthenium center. Indeed, the two
â-hydrogens of the η5-phospholyl in 4a are inequivalent
to each other and give two resonances at δ 5.10 and 5.45
in the 1H NMR spectrum. The 13C NMR spectrum of
1
4a showed two CR signals with a large J PC coupling
constant at δ 110.6 (J PC ) 66.2 Hz) and 113.2 (J PC
)
67.2 Hz) as well as two Câ signals at δ 79.9 (J PC ) 3.6
(12) Roberts, R. M. G.; Silver, J .; Wells, A. S. Inorg. Chim. Acta 1986,
119, 1.
(13) It was reported that a reaction of stannylcyclopentadiene with
[RuCl2(cod)]n in ethanol gave ruthenocene in high yield. See: (a) Liles,
D. C.; Shaver, A.; Singleton, E.; Wiege, M. B. J . Organomet. Chem.
1985, 288, C33. (b) Albers, M. O.; Liles, D. C.; Robinson, D. J .; Shaver,
A.; Singleton, E.; Wiege, M. B.; Boeyens, J . C. A.; Levendis, D. C.
Organometallics 1986, 5, 2321.

3064 Organometallics, Vol. 21, No. 14, 2002
Notes
prior to use. Ethanol was dried over magnesium, distilled, and
stored in a flask with a Teflon stopcock. Phenylphosphine,16
1,4-dicyclohexyl-1,3-butadiyne,17 1-phenylphospholes (5a,10 5c,18
5d 19), and [RuCl2(η4-C8H12)]n were prepared as reported.
20
nBu3SnCl was purchased from Tokyo Chemical Industry and
used after appropriate purification. Lithium metal, anhydrous
AlCl3, and Fe2(CO)9 were purchased from Aldrich Chemical
n
Co. and used as received. BuLi in hexane was obtained from
Kanto Chemicals. NMR spectra were recorded on a J EOL J NM
LA500 spectrometer (1H, 500 MHz; 13C, 125 MHz; 31P, 202
MHz). 1H and 13C chemical shifts were referenced to the
residual solvent (or the solvent) resonances and reported with
respect to tetramethylsilane. 31P NMR chemical shifts are
externally referenced to 85% H3PO4. Optical rotations were
measured on a J ASCO DIP-370 polarimeter.
1-P h en yl-2,5-d icycloh exylp h osp h ole (5b). A solution of
n-butyllithium in hexane (1.59 mol/L, 17.5 mL, 27.8 mmol) was
added dropwise to a solution of PhPH2 (3.02 g, 27.4 mmol) in
THF-C6H6 (80 mL, 1:1 mixture) at 0 °C. The resulting yellow
solution was added dropwise to a THF (20 mL) solution of 1,4-
dicyclohexyl-1,3-butadiyne (1.96 g, 9.14 mmol) by means of
cannula transfer. After the addition, the wine-red mixture was
heated to reflux for 2 h to give the reddish-brown suspension.
This suspension was quenched with water (ca. 1.5 mL), and
the mixture was evaporated to dryness under reduced pres-
sure. The residue was chromatographed on silica gel (elution
with hexane-CHCl3, 10:1) under nitrogen and then further
purified by recrystallization from hot EtOH to give the
analytically pure compound as colorless crystals. Yield: 1.64
F igu r e 2. ORTEP drawing of 8 with 50% thermal el-
lipsoids. All hydrogen atoms are omitted for clarity.
Selected bond lengths (Å) and angles (deg): P(1)-C(1) )
1.787(2), P(1)-C(4) ) 1.780(2), C(1)-C(2) ) 1.410(3), C(2)-
C(3) ) 1.415(3), C(3)-C(4) ) 1.415(3), Fe(1)-phopsholyl
) 1.671(3); C(1)-P(1)-C(4) ) 90.3(1), P(1)-C(1)-C(2) )
111.6(2), C(1)-C(2)-C(3) ) 113.3(2), C(2)-C(3)-C(4) )
113.1(2), P(1)-C(4)-C(3) ) 111.7(2).
Sch em e 2
1
g (5.05 mmol, 55%). Mp: 70.0-70.5 °C. H NMR (CDCl3): δ
1.05-1.25 (m, 10H), 1.57-1.60 (m, 2H), 1.66 (br, 4H), 1.77-
1.79 (m, 4H), 2.25-2.31 (m, 2H), 6.53 (d, J
) 12.9 Hz, 2H),
PH
7.25-7.34 (m, 5H). 13C{1H} NMR (CDCl3): δ 26.1, 26.6, 35.1
(d, J PC ) 45.3 Hz), 39.9 (d, J PC ) 15.7 Hz), 128.4 (d, J PC ) 8.2
Hz), 129.3 (d, J PC ) 1.6 Hz), 129.9 (d, J PC ) 10.3 Hz), 132.1
(d, J PC ) 9.8 Hz), 134.2 (d, J PC ) 19.4 Hz), 157.9 (d, J PC ) 4.9
Hz). 31P{1H} NMR (CDCl3): δ 2.55 (s). Anal. Calcd for
C
22H29P: C, 81.44; H, 9.01. Found: C, 81.56; H, 8.97.
Bis[η5-2,5-di((-)-m en th yl)-1-ph osph acyclopen tadien yl]-
the larger atomic radius of Ru than that of Fe. The
phospholyl-Fe distance in 8 is within the range of those
in the other structurally characterized diphosphafer-
rocenes;3b,4d,14 steric influence from the bulky cyclohexyl
sidearms was hardly detected in the solid state struc-
ture of 8. Thus, it can be deduced that the observed
structure of 4b, which is the homologue of 8, reflects
an electronic structure of an (η5-C4P)2Ru core.
r u th en iu m (II) (4a ). (a ) F r om th e Lith iu m P h osp h olid e
(m eth od A). A THF (3 mL) solution of the phosphole 5a (95.2
mg, 0.218 mmol) was treated with lithium metal (16.7 mg, 2.40
mmol), and the mixture was stirred at room temperature until
disappearance of 5a (checked by TLC). The mixture was
filtered through a glass filter, and to the filtrate was added
anhydrous AlCl3 (10.0 mg, 0.0750 mmol) at 0 °C. After allowing
to warm to room temperature, the THF solution was trans-
ferred onto a slurry of [RuCl2(η4-C8H12)]n (30.5 mg, 0.109 mmol/
Ru) in THF (1 mL), and the mixture was refluxed for 48 h.
After cooling the mixture, all the volatiles were removed under
reduced pressure. The residue was extracted with hexane. The
crude product was purified by preparative TLC on silica gel
(elution with hexane) under an argon atmosphere to give the
title compound in pure form. Yield: 61.7 mg (75.2 mmol, 69%).
Mp: 95-98 °C. 1H NMR (toluene-d8, 50 °C): δ 0.78 (d, J )
7.0 Hz, 6H), 0.80-1.09 (m, 44H), 1.25-1.33 (m, 6H), 1.57-
1.82 (m, 14H), 2.09 (sept of d, J ) 7.0 and 2.3 Hz, 2H), 2.17-
2.19 (m, 2H), 2.31 (sept of d, J ) 7.0 and 2.3 Hz, 2H), 5.09-
5.10 (br, 2H), 5.44-5.46 (br, 2H). 13C{1H} NMR21 (toluene-d8,
50 °C): δ 79.9 (d, J PC ) 3.6 Hz), 89.7 (d, J PC ) 3.6 Hz), 110.6
(d, J PC ) 66.2 Hz), 113.2 (d, J PC ) 67.2 Hz). 31P{1H} NMR
As reported for phosphaferrocenes3c,15a and phosphacy-
mantrenes,15b the diphospharuthenocenes have localized
lone pairs on the phosphorus atoms. Treatment of 4b
with 2.1 equiv of Fe2(CO)9 in boiling benzene gave a bis-
Fe(CO)4 complex 9 in nearly quantitative yield (Scheme
2). The complex 9 showed NMR characteristics (down-
field shift of the 31P NMR resonance and the smaller
1J CP value) similar to those of the previously known
phosphametallocene-P-Fe(CO)4 species.3c,15
Exp er im en ta l Section
Gen er a l Con sid er a tion s. All anaerobic and/or moisture-
sensitive manipulations were carried out with standard Schlenk
techniques under predried nitrogen or with glovebox tech-
niques under prepurified argon. Tetrahydrofuran and benzene
were distilled from sodium benzophenone-ketyl under nitrogen
(toluene-d8, 50 °C): δ -35.0 (s). [R]20 -224 (c 0.418, CHCl3).
D
(16) Bourumeau, K.; Gaumont, A.-C.; Denis, J .-M. J . Organomet.
Chem. 1997, 529, 205.
(17) Zweifel, G.; Lynd, R. A.; Murray, R. E. Synthesis 1977, 52.
(18) Breque, A.; Mathey, F.; Savignac, P. Synthesis 1981, 983.
(19) Fagan, P. J .; Nugent, W. A.; Calabrese, J . C. J . Am. Chem. Soc.
1994, 116, 1880.
(20) Albers, M. O.; Singleton, E.; Yates, Y. E. Inorg. Synth. 1989,
26, 253.
(21) Only the data for the phospholyl ring-carbon signals are given.
(14) (a) Hitchcock, P. B.; Lawless, G. A.; Maziano, I. J . Organomet.
Chem. 1997, 527, 305. (b) Qiao, S.; Hoic, D. A.; Fu, G. C. Organome-
tallics 1998, 17, 773.
(15) (a) Mathey, F. J . Organomet. Chem. 1978, 154, C13. (b) Breque,
A.; Mathey, F.; Santini, C. J . Organomet. Chem. 1979, 165, 129.

Notes
Organometallics, Vol. 21, No. 14, 2002 3065
Ta ble 1. Cr ysta llogr a p h ic Da ta for Com p lex 4b
a n d 8
Anal. Calcd for C48H80P2Ru: C, 70.29; H, 9.83. Found: C,
70.42; H, 10.10.
(b) F r om th e 1-Sta n n ylp h osp h ole (m eth od B). A THF
solution of the phosphole 5a (105 mg, 0.240 mmol) was treated
with lithium metal (16.7 mg, 2.40 mmol), and the mixture was
stirred at room temperature until disappearance of 5a (checked
by TLC). The mixture was filtered through a glass filter, and
to the filtrate was added tributyltin chloride (156 mg, 0.480
mmol) at 0 °C. After allowing to warm to room temperature,
THF was removed under reduced pressure and the residue
was dissolved in EtOH. The solution was added to [RuCl2(η4-
C8H12)]n (33.6 mg, 0.120 mmol/Ru), and the mixture was
refluxed for 48 h. After cooling the mixture, it was evaporated
to dryness under reduced pressure. The crude product was
purified by preparative TLC on silica gel (elution with hexane)
under an argon atmosphere to give the title compound in pure
form. Yield: 78.1 mg (95.2 mmol, 79%). All the spectroscopic
data are consistent with those described above.
4b
8
formula
fw
C
32H48P2Ru
C32H48P2Fe
550.53
595.75
color, habit
cryst size (mm)
cryst syst
space group
a (Å)
b (Å)
c (Å)
R (deg)
â (deg)
γ (deg)
V (Å3)
pale yellow, prismatic orange, prismatic
0.35 × 0.26 × 0.11
triclinic
P1h
0.10 × 0.15 × 0.20
triclinic
P1h
9.821(3)
13.428(3)
6.146(2)
100.83(2)
104.87(2)
72.24(2)
740.7(3)
1
1.335
6.56
314.00
Mo KR
0.71069
296
9.643(3)
13.394(7)
6.203(3)
100.97(4)
104.68(3)
71.66(3)
730.3(6)
1
Z
D
calc (g cm-3
)
1.252
6.44
296.00
Mo KR
0.71069
296
60
4624
µ (cm-1)
Bis(η5-2,5-d icycloh exyl-1-p h osp h a cyclop en t a d ien yl)-
r u th en iu m (II) (4b). The compound was prepared by either
method A or B as described above and purified by recrystal-
lization from hot hexane. Mp: 207-208 °C. 1H NMR (CDCl3):
δ 1.08-1.25 (m, 20H), 1.62-1.64 (m, 4H), 1.70-1.85 (m, 20H),
5.15 (d, J PH ) 4.8 Hz, 4H). 13C{1H} NMR (CDCl3): δ 26.21 (s),
26.80 (s), 26.87 (s), 36.37 (d, J PC ) 9.8 Hz), 37.06 (d, J PC ) 4.1
Hz), 40.24 (d, J PC ) 14.0 Hz), 80.63 (d, J PC ) 4.7 Hz), 112.49
(d, J PC ) 64.7 Hz). 31P{1H} NMR (CDCl3): δ -46.2 (s). Anal.
Calcd for C32H48P2Ru: C, 64.52; H, 8.12. Found: C, 64.25; H,
8.05.
F000
radiation type
wavelength (Å)
T (K)
2θmax (deg)
total no. of data
60
4558
no. of unique data 4324
4295
no. of obsd data
no. of variables
4021 (I > 3.00σ(I))
3031 (I > 3.00σ(I))
184
184
b
R,a Rw
0.024, 0.025
1.09
+0.67, -0.52
0.037, 0.038
1.14
+0.78, -0.28
gof
residual F (e Å-3)
Bis(η5-2,5-d icycloh exyl-1-p h osp h a cyclop en t a d ien yl)-
ir on (II) (8). A THF (15 mL) solution of the phosphole 5b (650
mg, 2.00 mmol) was treated with lithium metal (100 mg, 14.5
mmol), and the mixture was stirred at room temperature until
disappearance of 5b (checked by TLC). The mixture was
filtered through a glass filter, and to the filtrate was added
anhydrous AlCl3 (135 mg, 0.670 mmol) at 0 °C. After allowing
to warm to room temperature, the THF solution was trans-
ferred onto a slurry of anhydrous FeCl2 (130 mg, 1.03 mmol)
in THF (10 mL) by means of cannula. After stirring the
mixture for 12 h at room temperature, all the volatiles were
removed under reduced pressure. The residue was extracted
with hot octane, and the extract was passed through a short
pad of silica gel. Recrystallization from hot octane gave two
crops of prismatic bright-red crystals. Yield: 381 mg (692
mmol, 67%). Mp: 187-188 °C. 1H NMR (CDCl3): δ 1.10-1.36
(m, 20H), 1.65-1.68 (m, 4H), 1.74-1.78 (m, 8H), 1.92-1.95
(m, 4H), 1.99-2.08 (m, 8H), 4.82 (d, J PH ) 4.6 Hz, 4H). 13C-
{1H} NMR (CDCl3): δ 26.31 (s), 26.80 (s), 26.89 (s), 36.59 (d,
J PC ) 9.8 Hz), 36.69 (d, J PC ) 2.1 Hz), 40.44 (d, J PC ) 15.0
Hz), 79.84 (d, J PC ) 5.2 Hz), 111.28 (d, J PC ) 62.1 Hz). 31P-
{1H} NMR (CDCl3): δ -64.3 (s). Anal. Calcd for C32H48P2Fe:
C, 69.82; H, 8.79. Found: C, 69.80; H, 8.55.
a
b
2
R ) ∑||Fo| - |Fc||/∑|Fo|. Rw ) [∑w(|Fo| - |Fc|)2/∑w|Fo| ]1/2
where w ) 1/σ2(|Fo|).
Because of the light-sensitivity of the complex, satisfactory
elemental analysis data were not obtained.
X-r a y Str u ctu r e Deter m in a tion of 4b a n d 8. Suitable
crystals were obtained by recrystallization from hexane (4b)
or octane (8). Crystal data and other details of the structure
analyses are summarized in Table 1 and the Supporting
Information. Crystals of suitable size were mounted on glass
fibers and then transferred to a goniostat for characterization
and data collection. The data were corrected for Lorentz and
polarization effects. The structures were solved by direct
methods (SIR88 for 4b, SIR92 for 8) and expanded using
Fourier techniques. In the final cycles of refinement, the non-
hydrogen atoms were varied with anisotropic thermal param-
eters and the hydrogen atoms were varied with isotropic
thermal parameters. All calculations were performed using the
CrystalStructure22,23 crystallographic software package.
Ack n ow led gm en t. This work was supported by the
“Research for the Future” Program, the J apan Society
for the Promotion of Science, and a Grant-in-Aid for
Scientific Research, the Ministry of Education, J apan.
K.Y. thanks the J apan Society for the Promotion of
Science for the award of a fellowship for graduate
students.
Bis(η5-2,5-d icycloh exyl-P -tetr a ca r bon ylir on (0)-1-p h os-
p h a cyclop en ta d ien yl)r u th en iu m (II) (9). A mixture of 4b
(60 mg, 0.10 mmol) and Fe2(CO)9 (75 mg, 0.21 mmol) was
suspended in benzene (5 mL) and refluxed for 8 h. The cooled
mixture was evaporated to dryness under reduced pressure.
The residue was chromatographed on silica gel with deoxy-
genated hexane-benzene (80:20). After removal of the solvent
under reduced pressure, the title complex was obtained as a
yellow powder. Yield: 85 mg (90%). The complex was light-
sensitive and slowly decomposed into uncharacterized species.
1H NMR (CDCl3): δ 1.16-1.35 (m, 20H), 1.56-1.94 (m, 24H),
5.50 (d, J PH ) 16.5 Hz, 4H). 13C{1H} NMR (CDCl3): δ 25.85
(s), 26.77 (s), 26.95 (s), 33.91 (vt, J PC ) 3.1 Hz), 37.00 (br),
37.85 (vt, J PC ) 5.7 Hz), 80.94 (d, J PC ) 4.1 Hz), 105.13 (d, J PC
) 3.6 Hz), 214.66 (br). 31P{1H} NMR (CDCl3): δ 32.95 (s).
Su p p or tin g In for m a tion Ava ila ble: Tables of crystal-
lographic data for 4b and 8. This material is available free of
charge via the Internet at http://pubs.acs.org.
OM020189I
(22) CrystalStructure 2.00, Crystal Structure Analysis Package;
Rigaku and MSC, 2001.
(23) Watkin, D. J .; Prout, C. K.; Carruthers, J . R.; Betteridge, P.
W. CRYSTALS Issue 10; Chemical Crystallography Laboratory: Ox-
ford, UK.