1712
S. Bolano et al. / Polyhedron 22 (2003) 1711Á
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1717
˜
2. Experimental
Cy), 3.48 (s, 3H, OCH3), 4.22 (m, 2H, CH2), 4.37 (m,
2H, CH2). 13C{1H} NMR (CHCl3-d, 100 MHz): dꢀ
/
2.1. Materials and instrumentation
67.4 (s, Ã
26.3Á
27.8 (m, Cy). 31P{1H} NMR (CHCl3-d, 161
MHz): dꢀ126.1 (s). Anal. Found: C, 42.73; H, 6.78.
Calc. for C27H51Cl2O4P2Re (758.22): C, 42.74; H,
6.77%. MS: m/z (referred to the most abundant
/
(CH2)2Ã
/
), 59.0 (s, OCH3), 40.2Á
/
41.0 (m, Cy),
/
All synthetic operations were performed under dry
argon. A standard vacuum system and Schlenk type
glassware were used in handling metal complexes.
Solvents were pre-dried over sodium wire or calcium
chloride before reflux and subsequent distillation, under
argon, from a suitable drying agent [13]. Deuterated
solvents for NMR measurements (Aldrich) were dried
over molecular sieves. The complex [ReOCl3(AsPh3)2]
was prepared after Michos et al. [14]. All other
commercially available reagents were used as purchased.
The IR spectra of samples in KBr pellets were
recorded on a Bruker Vector IFS28 FT spectrophot-
ometer, and NMR spectra on a Bruker AMX 400
/
isotopes): 758, [M]; 727, [MÃ
/
OCH3]; 723, [MÃ
/
Cl]; 707,
[MÃOÃCl]; 692, [MÃClÃOCH3]. The isotope patterns
/
/
/
/
match those simulated. Single crystals were obtained by
slow evaporation of an MeOH/CH2Cl2 (10:2, v/v)
solution.
2.4. Crystallization of [ReOCl3L2] (2)
This complex was synthesized as previously reported
[11]: [ReOCl3(AsPh3)2] was reacted with L2 in THF. The
addition of methanol to the formed oil produced a violet
precipitate. After dissolving the solid in a Cl2CH2/EtOH
(10:2, v/v) mixture, X-ray suitable crystals were isolated.
1
spectrometer. H and 13C{1H} signals are referred to
internal TMS, and 31P{1H} chemical shifts to 85%
H3PO4, with downfield shifts considered positive.
Mass spectra were recorded in the LSIMS, Csꢁ mode
on a Micromass Autospec M instrument. Elemental
analyses were carried out on a Fisons EA-1108 appara-
tus.
2.5. Preparation of [ReOCl2(OEt)L2] (3)
Hundred milligram of [ReOCl3L2] suspended in
ethanol (20 ml) were refluxed under Ar. After 2Á3 h a
/
2.2. Synthesis of the ligand Cy2POCH2CH2OPCy2 (L1)
change of colour (from violet to pink) was observed.
From this suspension a pink solid was filtered off and
dried in vacuo (80% yield). The same complex was
The ligand was synthesized by the method previously
reported [12]: Cy2PCl (5 g, 21 mmol) was slowly added
obtained as follows:
a
suspension of [Re-
dropwise (ca. 30 min) to a cooled (ꢂ
/
80 8C) solution of
Cl3L2{PPh2(OEt)}] (100 mg) in ethanol (15 ml) was
stirred and air-ventilated for 4 h. The solid formed was
freshly distilled Et3N (2.93 ml, 21 mmol) and ethylene
glycol (0.59 ml, 10 mmol) in 56 ml of toluene. The
solution was stirred for 2 h and the formation of the
ligand was established by the presence of a unique signal
at 150.1 ppm in the 31P{1H} spectrum. The formed
solid, [Et3NH]Cl, was filtered off.
Attempts to isolate this product (by distillation and
column chromatography) were unsuccessful due to its
unstability, as shown by the disappearance of the
characteristic signal in the 31P{1H} spectrum. So that,
a ligand solution in toluene was used for the synthesis of
the complexes, this solution being stable at room
temperature for 1 week when stored under argon.
filtered off and dried under vacuum (70% yield). IR
1
O). H NMR (CHCl3-
(KBr pellets, cmꢂ1): 910s, n(ReÄ
/
d, 400 MHz): d (ppm)ꢀ
2.13 (q, 2H, CH2 Jꢀ7.0 Hz), 4.24Á
7.57Á
8.42 (m, 20H, Ph). 13C{1H} NMR (CHCl3-d, 100
MHz): d (ppm)ꢀ135.3 (t, Co,m Ph, Jꢀ6.0 Hz), 133.2
(s, Cp Ph), 131.9 (t, Co,m Ph, Jꢀ4.8 Hz), 131.8 (s, Cp
Ph), 129.2 (t, Co,m Ph, Jꢀ5.2 Hz), 128.3 (t, Co,m Ph,
Jꢀ5.6 Hz), 66.7 (s, CH2CH2), 64.6 (s, OCH2), 14.4 (s,
CH3). 31P{1H} NMR (CHCl3-d, 161 MHz): dꢀ
104.7
/
ꢂ
/
0.16 (t, 3H, CH3 Jꢀ
/
7.0 Hz),
/
/
4.46 (m, Ã(CH2)2Ã
/
/)
/
/
/
/
/
/
/
(s). Anal. Found: C, 45.02; H, 3.80. Calc. for
C28H29Cl2O4P2Re (748.04): C, 44.92; H, 3.88%. Single
crystals were obtained by slow evaporation of an EtOH/
CH2Cl2 (10:2, v/v) solution.
2.3. Synthesis of [ReOCl2(OMe)L1] (1)
A 0.12 M solution of L1 in toluene (9.2 ml) was added
to a solution of [ReOCl3(AsPh3)2] (1 g, 1 mmol) in
tetrahydrofuran (40 ml). The resulting mixture was
refluxed under argon for 1 h. After stirring for 3 h at
room temperature and concentrating in vacuo a dark oil
was formed. This oil was tritured with methanol,
resulting in a violet precipitate that was filtered off,
2.6. X-ray crystallography
Crystallographic data were collected on a Bruker
Smart CCD diffractometer at 293 K using graphite
˚
0.71073 A) and were
monochromated Mo Ka (lꢀ
/
corrected for Lorentz and polarization effects. The
frames were integrated with the Bruker SAINT [15]
software package and the data were corrected for
absorption using the program SADABS. The structures
were solved by direct methods using the program
washed with methanol and dried under vacuum (0.46 g,
1
O). H
56% yield). IR (KBr pellets, cmꢂ1): 945s, n(ReÄ
/
NMR (CHCl3-d, 400 MHz): dꢀ
/
1.14Á2.89 (m, 44H,
/
Bola?o, Sandra
