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A. Palazzi et al. / Journal of Organometallic Chemistry 689 (2004) 2324–2337
Schlenk techniques. Solvents were dried and distilled
under nitrogen prior to use. The prepared deriva-
tives were characterised by elemental analysis and
spectroscopic methods. IR spectra were recorded with
a FT-IR spectrometer Perkin–Elmer Spectrum 2000.
The routine NMR spectra (1H, 13C) were always
(WCOax), 197.7 (WCOeq), 142.4 (NCW), 135.9
(CH3CN), 133.5 132.2, 131.4, 130.9 129.8 (C6H5), 84.9
(C5H5), 5.3 (CH3CN). KM (10ꢀ3 M in CH3CN, r.t.):
125 Xꢀ1 cm2 molꢀ1. Anal. Calc. for C32H23N2O6PFeW:
C, 47.9; H, 2.87; N, 3.5. Found: C, 48.1; H, 2.85; N,
3.7%. (2b) 0.195 g, 41%, red oil. IR (CH2Cl2) mmax
(cmꢀ1): 2196m, 2103w (CN), 2058w, 2024m, 1921vs
1890sh (CO); NMR: dH (CDCl3, 25 ꢀC): 7.5–7.3 (m,
5H, C6H5), 4.9 (s, 5H, C5H5) 2.2 (s, 2H, CH2-Ph), 2.0
(s, 3H, CH3CN); dC (CDCl3, r.t.), 213.5 (Fe–CO), 152.9
(CNBenzyl), 134.8 (CH3CN), 132.3, 129.9, 129.6, 127.6
(C6H5), 83.8 (C5H5), 50.1 (CH2), 5.4 (CH3CN); dC
(CDCl3 )50 ꢀC): 212.7 (Fe–CO), 200.5 (WCOax), 197.1
(WCOeq), 150.9 (CNBenzyl), 142.1 (NCW), 133.2
(CH3CN), 131.4, 129.3, 129.0, 127.0 (C6H5) (C5H5),
49.2 (CH2), 5.4 (CH3CN); KM (10ꢀ3 M in CH3CN,
recorded using
a Varian Gemini 300 instrument
(1H, 300.1; 13C, 75.5 MHz). The spectra were refer-
enced internally to residual solvent resonance, and
were recorded at 298 K for characterisation pur-
poses. Elemental analyses were performed on a Ther-
moQuest Flash 1112 Series EA Instrument. The
compounds
[CpFe(CO)2CN],
Na[M(CO)5(CN)],
(M ¼ Cr, Mo, W) were prepared by the literature
procedures. Cationic precursors like [Cp(CO)-
(L)Fe(THF)]þ, [L ¼ PPh3 (1a), CN-Benzyl (1b), CN-2,6-
Me2C6H3 (1c); CN-But (1d), P(OMe)3 (1e), P(Me)2Ph
(1f), CO (1g)] were prepared from the correspond-
r.t.): 115 Xꢀ1 cm2 molꢀ1
.
Anal. Calc. for
C22H15N3O6FeW: C, 40.2; H, 2.28; N, 6.4. Found: C,
40.5; H, 2.31; N, 6.5%. (2c) 0.200 g, 42%, dark mi-
crocrystalline powder. IR (CH2Cl2) mmax (cmꢀ1): 2157s,
2104w (CN), 2024s, 1921vs, 1890sh (CO); NMR: dH
(CDCl3): 7.3–7.1 (m, 3H, C6H3-2,6-(CH3)2), 5.2 (s, 5H,
C5H5) 2.5 (s, 6H, C6H3-2,6-(CH3)2) 2.3 (s, 3H,
CH3CN); dC (CDCl3); 212.3 (Fe–CO), 163.9
(CNC6H3(CH3)2), 134.7 (CH3CN), 134.9, 129.4, 128.1,
127.4 (C6H3(CH3)2), 84.0 (C5H5), 18.5 (C6H3(CH3)2),
5.0 (CH3CN); KM (10ꢀ3 M in CH3CN, r.t.): 115 Xꢀ1
cm2 molꢀ1. Anal. Calc. for C23H17N3O6FeW: C, 41.1;
H, 2.53; N, 6.3. Found: C, 41.5; H, 2.55; N, 6.2%. (2d)
0.150 g, 33%, yellow oil. IR(CH2Cl2) mmax (cmꢀ1):
2181m, 2104w (CN), 2056w, 2020s, 1921vs (CO);
NMR: dH (CDCl3): 5.1 (s, 5H, C5H5), 2.3 (s, 3H,
CH3CN), 1.6 (s, 9H, C(CH3)3); dC (CDCl3): 213.5 (Fe-
C O), 148.8 (CNBut), 83.7 (C5H5), 60.1 (CCH3), 30.7
(CCH3), 5.0 (CH3CN); KM (10ꢀ3 M in CH3CN, r.t.):
121 Xꢀ1 cm2 molꢀ1. Anal. Calc. for C19H17N3O6FeW:
C, 36.6, H, 2.73, N, 6.7. Found: C, 36.8; H, 2.77; N,
6.5%. (2e) 0.180 g, 38%, red oil. IR (CH2Cl2) mmax
(cmꢀ1): 2103w (CN), 2058w, 2004m, 1920vs, 1890sh
(CO); NMR: dH(CDCl3): 4.9 (s, 5H, C5H5) 3.7 (9H, d,
ing iodides [25] by reaction with
a stoichiome-
tric amount of Ag(CF3SO3) in a THF solution (15 ml)
at room temperature. Filtration through a Celite
pad and subsequent evaporation to dryness afforded
a mixture which was used without any further purifica-
tion. All reactions were monitored by IR spectroscopy.
Petroleum ether (Etp) refers to a fraction of b.p. 60–
80 ꢀC. Typically, all chromatographies were performed
on alumina column (diameter:1.5 cm; height 15 cm)
under Argon atmosphere and using petroleum ether-
dichloromethane mixtures as eluant.
4.2. Typical procedure for the preparation of
[Cp(CO)(L)Fe(NCCH3)][NCW(CO)5] [L ¼ PPh3
(2a); CN-Benzyl (2b); CN-2,6-Me2C6H3 (2c); CN-
But (2d); P(OMe)3 (2e); P(Me)2Ph (2f)]
Complexes 1a–f (0.71 mmol), dissolved in dry ace-
tonitrile (10 ml), was added dropwise to a stirred sus-
pension of Na[W(CO)5(CN)] (0.270 g, 0.71 mmol) in 15
ml of CH3CN. The resulting dark mixture was main-
tained at )30 ꢀC for 2 h, then left to warm to room
temperature. Filtration through a Celite pad and
evaporation to dryness afforded a crude product which
was purified by alumina column chromatography.
CH2Cl2 was first used as eluant to remove neutral im-
purities, after which the fractions containing the title
compounds 2a–f were obtained by eluting with
CH3CN. (2a) 0.270 g, 50%, red crystals obtained from
a dichloromethane solution of pure 2a layered with
diethyl ether at )5 ꢀC. IR (CH2Cl2) mmax (cmꢀ1): 2102w
(CN); 2057w, 1990m,1920vs,1895sh (CO); NMR: dH
(CDCl3) 7.2–7.7 (m, 15H, C6H5), 4.7 (s, 5H, C5H5), 2.0
(s, 3H, CH3CN); dC (CDCl3; 25 ꢀC): 216.4 (FeCO, d,
2JCP ¼ 40 Hz), 135.9 (CH3CN), 133.4 133.2 132.5, 131.6
131.9 129.8 (C6H5); 84.7 (C5H5) 5.2 (CH3CN); dC
3
(OCH3)3, JHP ¼ 9 Hz) 2.3 (s, 3H, CH3CN); dC
3
(CDCl3): 214.1 (FeCO, d, JCP ¼ 45 Hz), 135.3 (CH3C
3
N), 83.8 (C5H5), 53.7 (OCH3, d, JCP ¼ 5 Hz), 5.18
(CH3CN). KM (10ꢀ3 M in CH3CN, r.t.): 116 Xꢀ1 cm2
molꢀ1. Anal. Calc. for C17H17N2O9PFeW: C, 30.7; H,
2.56; N, 4.2. Found: C, 30.9; H, 2.60; N, 4.4%. (2f)
0.238 g; 50%, red oil. IR (CH2Cl2) mmax (cmꢀ1): 2104w,
2059w, 1986m, 1922vs, 1898sh (CO); NMR: dH
(CDCl3) 7.4–7.7 (m, 5H, C6H5), 4.8 (s, 5H, C5H5), 2.3
(s, 6H, CH3), 2.0 (s, 3H, CH3CN); dC (CDCl3): 215.9
(FeCO, d, 3JCP ¼ 30 Hz), 134.8 (CH3C N), 135.9, 135.3,
131.1, 129.6, 129.4, 129.3 (C6H5), 83.6 (C5H5), 16.9,
2
2
(PCH3, d, JCP ¼ 15 Hz), 17.4 (PCH3, d, JCP ¼ 15 Hz),
5.4 (CH3CN); KM (10ꢀ3 M in CH3CN, r.t.): 120 Xꢀ1
cm2 molꢀ1; Anal. Calc. for C22H19N2O6PFeW: C, 38.9;
H, 2.80; N, 4.1. Found: C, 39.1; H, 2.85; N, 4.3%.
2
(CDCl3; )30 ꢀC): 216.6 (FeCO, d, JCP ¼ 35 Hz) 201.1