Article
Organometallics, Vol. 28, No. 20, 2009 6129
ventilated hood, and then the mixture was extracted with CHCl3
(30 mLꢀ3). After CHCl3 was removed, the remaining red oil was
distilled under vacuum to give the product as a light yellow oil
(0.479 g, 55%), bp 45-46 °C (1 mmHg). This compound was
identified by comparison of its IR and 1H NMR data with those
of an authentic sample prepared by another method.36
Preparation of [(μ-SeCH2)2CH(OH)]Fe2(CO)6 (A). To a deep
green solution of Fe3(CO)12 (0.504 g, 1.00 mmol) in toluene
(25 mL) was added 2-hydroxypropane-1,3-diselenol (0.220 g,
1.00 mmol). The mixture was refluxed for 1.5 h, resulting in a color
change from deep green to dark red. After solvent was removed in
vacuo, the residue was subjected to flash column chromatography
using petroleum ether to remove the soluble and insoluble impu-
rities and then using acetone to elute the major red band. After
acetone was removed in vacuo, the residue was further subjected to
TLC separation using acetone/petroleum ether (1:4 v/v) as eluent.
From the main red band, A was obtained as a red solid (0.253 g,
51%), mp 96-97 °C. Anal. Calcd for C9H6Fe2O7Se2: C, 21.80; H,
1.22. Found: C, 21.75; H, 1.24. IR (KBr disk): νCtO 2068 (s), 2024
(vs), 1989 (vs); νO-H 3418 (m) cm-1. 1H NMR (300 MHz, CDCl3,
Fe2O6PSe2: C, 42.78; H, 2.90. Found: C, 42.72; H, 2.98. IR
(KBr disk): νCtO 2037 (vs), 1975 (vs), 1928 (m); νO-H 3387 (m)
cm-1. 1H NMR (400 MHz, CDCl3, TMS): 1.16 (d, 1H, J=3.6
0
Hz, OH), 1.27 (d, 2Ha, JHaHe=11.2 Hz), 1.54-1.59 (m, 1Ha ),
2.23 (d, 2He, JHeHa=10.0 Hz), 7.45, 7.64 (2s, 15H, 3C6H5) ppm.
31P NMR (162 MHz, CDCl3, 85% H3PO4): 67.88 (s) ppm. 77Se
NMR (57 MHz, CDCl3, Me2Se): 182.38 (s) ppm.
Preparation of [(μ-SeCH2)2CH(OCOPh)]Fe2(CO)5(PPh3)
(2). A solution of 1 (0.365 g, 0.50 mmol) in CH2Cl2 (15 mL)
was cooled to 0 °C, and then Et3N (0.07 mL, 0.50 mmol) and
benzoyl chloride (0.06 mL, 0.50 mmol) were added. The mixture
was warmed to room temperature and stirred at this tempera-
ture for 12 h. After solvent was removed in vacuo, the residue
was subjected to TLC separation using CH2Cl2/petroleum ether
(1:3 v/v) as eluent. From the main red band, 2 was obtained as a
red solid (0.317 g, 76%), mp 95 °C (dec). Anal. Calcd for
C33H25Fe2O7PSe2: C, 47.52; H, 3.02. Found: C, 47.40; H,
3.09. IR (KBr disk): νCtO 2034 (vs), 1977 (vs), 1959 (vs), 1930
1
(s); νCdO 1711 (s) cm-1. H NMR (400 MHz, CDCl3, TMS):
0
1.52 (t, 2Ha, JHaHe=JHaHa =11.4 Hz), 2.47 (d, 2He, J HeHa=10.0
0
Hz), 3.68-3.74 (m, 1Ha ), 7.41-8.08 (m, 20H, 4C6H5) ppm. 31P
0
TMS): 1.53 (t, 2Ha, JHaHe=JHaHa =11.1 Hz), 1.85 (d, 1H, J=5.1
0
NMR (162 MHz, CDCl3, 85% H3PO4): 67.30 (s) ppm. 77Se
Hz, OH), 2.84 (d, 2He, JHeHa=12.0 Hz), 2.97-3.03 (m, 1Ha ) ppm
(Ha and He denote the axially and equatorially bonded H atoms in
NMR (57 MHz, CDCl3, Me2Se): 190.35 (s) ppm.
Preparation of [(μ-SeCH2)2CH(OPPh2)-η1]Fe2(CO)5 (3). To
a red solution of A (0.248 g, 0.50 mmol) in THF (15 mL) cooled
to 0 °C were added Et3N (0.07 mL, 0.50 mmol) and Ph2PCl (0.09 mL,
0.50 mmol). After the mixture was stirred at 0 °C for 0.5 h, it was
allowed to warm to room temperature and stirred at this
temperature for 12 h. Solvent was removed in vacuo, and the
residue was subjected to TLC separation using CH2Cl2/petro-
leum ether (1:2 v/v) as eluent. From the main red band, 3 was
obtained as a red solid (0.255 g, 78%), mp 174 °C (dec). Anal.
Calcd for C20H15Fe2O6PSe2: C, 36.85; H, 2.32. Found: C, 36.93;
H, 2.27. IR (KBr disk): νCtO 2043 (s), 1982 (vs), 1963 (vs), 1925
0
0
CH2Se groups, while Ha and He represent those axially or
equatorially bonded to bridgehead C atom). 77Se NMR (57
MHz, CDCl3, Me2Se): 207.36 (s) ppm.
Preparation of A and (μ-EtSe)[μ-SeCH2CH(OH)(CH2Br)]Fe2-
(CO)6 (B). (i) The procedure for complex A as major product: A
purple-red solution of (μ-Se2)Fe2(CO)6 (0.438 g, 1.00 mmol) in
THF (25 mL) was cooled to -78 °C, and then Et3BHLi (2.0 mL,
2.00 mmol) was added. The mixture was stirred at -78 °C for 20
min to give a brown-red solution containing (μ-LiSe)2Fe2(CO)6.
After 1,3-dibromo-2-propanol (0.12 mL, 1.00 mmol) was added,
the new mixture was warmed to room temperature and stirred at
this temperature for 12 h. Volatiles were removed in vacuo, and the
residue was subjected to TLC separation using CH2Cl2/petroleum
ether (1:1 v/v) as eluent. From the main red band, B was obtained
as a red oil (0.080 g, 13%). When the eluent was changed to
acetone/petroleum ether (1:4 v/v), A was obtained from another
main red band as a red solid (0.111 g, 22%). Complex A was
identified by melting point and IR and 1H NMR spectral compar-
ison with the same compound prepared in the reaction of (HSe-
CH2)2CHOH with Fe3(CO)12. Complex B was characterized by
elemental analysis and spectroscopy. Anal. Calcd for
C11H11BrFe2O7Se2: C, 21.85; H, 1.83. Found: C, 22.01; H, 1.85.
IR (KBr disk): νCtO 2064 (s), 2023 (vs), 1980 (vs); νO-H 3407 (m)
(s) cm-1 1H NMR (300 MHz, CDCl3, TMS): 1.97 (d, 2Ha,
.
J
HaHe=12.3 Hz), 2.60 (d, 2He, JHeHa=9.9 Hz), 4.39-4.48 (m,
1He ), 7.48-7.75 (m, 10H, 2C6H5) ppm. 31P NMR (121 MHz,
CDCl3, 85% H3PO4): 159.47 (s) ppm. 77Se NMR (57 MHz,
CDCl3, Me2Se): 4.35 (s) ppm.
0
Preparation of [(μ-SeCH2)2CH(OPPhCl)-η1]Fe2(CO)5 (4).
To a red solution of A (0.248 g, 0.50 mmol) in MeCN (15 mL)
was added PhPCl2 (0.07 mL, 0.50 mmol), and then the mixture
was stirred at room temperature for 12 h. After solvent was
removed in vacuo, the residue was subjected to TLC separation
using CH2Cl2/petroleum ether (1:3 v/v) as eluent. From the main
red band, 4 was obtained as a red solid (0.210 g, 69%), mp 143 °C
(dec). Anal. Calcd for C14H10ClFe2O6PSe2: C, 27.55; H, 1.65.
Found: C, 27.54; H, 1.63. IR (KBr disk): νCtO 2036 (vs), 1987
cm-1
.
1H NMR (400 MHz, d6-acetone, TMS): 1.19
(t, J=7.6 Hz, a-CH2CH3), 1.44 (t, J=7.6 Hz, e-CH2CH3), 1.49
(t, J = 7.4 Hz, e-CH2CH3), 2.42-3.07 (m, 4H, SeCH2CH3,
SeCH2CH), 3.45-3.64 (m, 2H, BrCH2), 3.74-3.81 (m, e-CH2-
CH), 4.00-4.08 (m, e-CH2CH), 4.10-4.15 (m, a-CH2CH), 4.80
(d, J=5.2 Hz, e-CH2CHOH), 4.99 (d, J=5.2 Hz, e-CH2CHOH),
5.03 (d, J=5.2 Hz, a-CH2CHOH) ppm. 77Se NMR (76 MHz,
CDCl3, Me2Se): 95.73 (s), 146.92 (s), 155.84 (s), 160.81 (s), 203.07
(s), 206.97 (s) ppm. (ii) Another procedure for complex B as
major product: To the prepared THF solution from
(μ-Se2)Fe2(CO)6 (0.438 g, 1.00 mmol) and Et3BHLi (2.0 mL,
2.00 mmol) as described in procedure (i) was added an excess
amount 1,3-dibromo-2-propanol (0.36 mL, 3.00 mmol), and then
the new mixture was stirred at room temperature for 12 h. After
the same workup as that described in procedure (i), complexes B
(0.190 g, 31%) and A (0.015 g, 3.0%) were obtained, respectively.
Preparation of [(μ-SeCH2)2CH(OH)]Fe2(CO)5(PPh3) (1). A
solution of A (0.248 g, 0.50 mmol), PPh3 (0.131 g, 0.50 mmol),
(vs), 1970 (vs), 1941 (s) cm-1 1H NMR (400 MHz, CDCl3,
.
TMS): 1.95, 2.15 (2d, 2Ha, JHaHe=12.8 Hz), 2.54, 2.95 (2d, 2He,
0
J
HeHa=12.8 Hz), 4.62-4.66 (m, 1He ), 7.60-8.02 (m, 5H, C6H5)
ppm. 31P NMR (162 MHz, CDCl3, 85% H3PO4): 207.66 (s) ppm.
77Se NMR (57 MHz, CDCl3, Me2Se): 10.98 (s), 43.03 (s) ppm.
Preparation of (μ-EtSe)[μ-SeCH2CH(CH2Br)(O2CC5H4N-
4)]Fe2(CO)6 (5). A solution of B (0.302 g, 0.50 mmol) in CH2Cl2
(15 mL) was cooled to 0 °C, and then Et3N (0.07 mL, 0.50 mmol)
and 4-pyridinecarboxylic acid chloride (0.071 g, 0.50 mmol) were
added. After the mixture was stirred at 0 °C for 0.5 h, it was
warmed to room temperature and stirred at this temperature for 12
h. Solvent was removed in vacuo, and the residue was subjected to
TLC separation using CH2Cl2 as eluent. From the main orange-
red band, 5 was obtained as a red oil (0.352 g, 99%). Anal. Calcd
for C17H14BrFe2NO8Se2: C, 28.77; H, 1.99; N, 1.97. Found: C,
28.67; H, 2.07; N, 2.08. IR (KBr disk): νCtO 2064 (s), 2025 (vs),
1982 (vs); νCdO 1737 (s) cm-1. 1HNMR(300MHz, CDCl3, TMS):
1.13 (t, J=7.5 Hz, a-CH2CH3), 1.38(t, J=7.5 Hz, e-CH2CH3), 1.45
(t, J = 7.5 Hz, e-CH2CH3), 2.22-3.07 (m, 4H, SeCH2CH3,
SeCH2CH), 3.63-3.71 (m, 2H, BrCH2), 5.03-5.10 (m, e-
CH2CH), 5.37-5.44 (m, e-CH2CH), 5.49-5.55 (m, a-CH2CH),
7.95 (s, 2H, 2 R-H of pyridine ring), 9.00 (s, 2H, 2 β-H of pyridine
and Me3NO 2H2O (0.056 g, 0.50 mmol) in MeCN (15 mL) was
3
stirred at room temperature for 0.5 h. The resulting dark red
solution was evaporated to dryness in vacuo, and the residue
was separated by TLC using acetone/petroleum ether (1:3.5 v/v)
as eluent. From the main red band, 1 was obtained as a red solid
(0.295 g, 81%), mp 150 °C (dec). Anal. Calcd for C26H21-