Synthesis of Li[Mo(g5-C5H4NMe2)(CO)3]·2DME (Li·7·2D-
ME). Solid [Mo(CO)6] (2.87 g, 10.86 mmol) was added to a
solution of Li(C5H4NMe2) (1.25 g, 10.86 mmol) in 100 mL
dimethoxyethane (DME). The mixture was refluxed for 4 h with
constant stirring. The disappearance of [Mo(CO)6] was followed
by IR spectroscopy. After concentration of the solution and
precipitation with pentane (200 mL), the compound Li·7·2DME
was isolated, washed with pentane (3 × 50 mL) and dried in vacuo
to give a brown oil. The o◦il is very sensitive toward oxidation
and should be kept at −30 C. There are two moles of DME of
Experimental
General procedures
Reactions were carried out under an atmosphere of nitrogen by
means of conventional Schlenk techniques. Hexane was distilled
from sodium/potassium alloy, toluene from sodium, diethyl ether
from sodium/benzophenone, and dichloromethane from calcium
dihydride. When indicated, melting points were determined in
sealed capillaries on a Bu¨chi 510 melting point apparatus and are
uncorrected. Elemental analyses were performed by Analystische
Laboratorien, Prof. Dr. H. Malissa and G. Reuter GmbH, D-
51789 Lindlar, Germany and by the “Service de Microanalyses”,
Universite´ Louis Pasteur, Strasbourg.
NMR spectra were recorded on a Varian Unity 500 (1H,
500 MHz; 13C, 125.7 MHz; 11B, 160.4 MHz; 31P, 202.4 MHz),
a Varian VXR 300 or Bruker Avance 300 (1H, 300 MHz;
13C, 75.47 MHz; 31P, 121.49 MHz) or a Varian Mercury 200
(1H, 200 MHz) spectrometer. Chemical shifts (in ppm) were
measured at ambient temperature and are referenced to internal
TMS for 1H and 13C and to external BF3·OEt2 for 11B, and
external H3PO4 (84%) for 31P, with downfield shifts reported
as positive. The spectra were measured at 298 K. Deuterated
solvents for NMR spectroscopy were degassed, dried and stored
1
solvation per mole of anion, this was determined by H NMR
spectroscopy. Yield 4.45 g, 86%.
Data for Li·7·2DME. 1H NMR ((CD3)2CO): AAꢀXXꢀ system
d 4.76 and 4.45 (2 pseudo-t, 8H, Cp), 3.48 (s, 8H, CH2, DME), 3.30
(s, 12H, CH3, DME), 2.34 (s, 6H, N(CH3)2). IR (THF): m(CO):
1898s, 1799vs, 1773sh, 1709s cm−1.
Synthesis of [Au{Mo(g5-3,5-Me2C5H3BNi-Pr2)(CO)3}(PPh3)]
(Mo–Au) (10). A mixture of [AuCl(PPh3)] (0.60 g, 1.21 mmol)
and Li·6·2DME (0.70 g, 1.23 mmol) in toluene (30 mL) was stirred
for 2 h. The reaction mixture was then filtered through a frit
covered with silica (9 cm layer). Concentration of the filtrate gave a
viscous residue which was triturated with pentane to form a yellow
suspension. The yellow solid was collected on a frit, washed with
pentane (2 × 5 mL) and recrystallized from toluene to afford 10
(0.89 g, 87%); mp 171–172 ◦C.
˚
over molecular sieves (4 A Merck). Assignments are based
on APT and DEPT spectra and 1H, 1H-COSY and 1H, 13C-
HMQC experiments. IR spectra were recorded in the region
4000–400 cm−1 on a Nicolet Avatar 360 FT IR spectrometer or a
IFS66 Bruker spectrometer. The following compounds were syn-
thesized according to literature procedures: Li(3,5-Me2C5H3BNi-
Pr2),11 Li(C5H4NMe2),18 [AuCl(PPh3)],31 trans-[PtCl2(CNt-Bu)2]20
and trans-[PtCl2(NCPh)2].19,32 The compound C5H5NMe2 was
obtained by reaction of TsONMe233 with Na(C5H5)·DME,34 which
is a slight modification of the literature procedure in which
methylsulfonyl chloride was reacted with Li(C5H5).18
Data for 10. Anal. Calc. for C34H38AuBMoNO3P: C, 48.42;
1
H, 4.54; N, 1.66. Found: C, 48.76; H, 4.25; N, 1.98%. H NMR
(C6D6): d 5.08 (br s, couplings not resolved, 1H, H-4), 4.58 (br s,
coupling not resolved, 2H, H-2/6), 2.02 (s, 6H, Me-3/5); Ni-Pr2:
3.57 (sept, 2H, NCH), 1.25 (d, 12H, Me, 3J = 6.8 Hz); PPh3: 7.5
1
(m, 6 Ho), 7.0 (m, 6 Hm + 3 Hp). 13C{ H} NMR (C6D6): d 228.4
(CO), 127.1 (C-3/5), 86.4 (br, C-2/6), 84.2 (C-4), 25.7 (Me-3/5);
Ni-Pr2: 46.2 (NCH), 22.7 (Me); PPh3: 134.3 (d, JPC = 15 Hz, Co),
131.3 (d, JPC = 11 Hz, Cm), 131.1 (d, JPC = 51 Hz, Ci), 129.0 (d,
JPC = 2 Hz, Cp). 11B NMR (C6D6): d 24.7. IR (KBr): m(CO): 1952s,
1862s, 1828s cm−1.
Synthesis of Li[Mo(g5-3,5-Me2C5H3BNi-Pr2)(CO)3]·2 DME
(Li·6·2DME). Solid [Mo(CO)6] (3.98 g, 15.1 mmol) was added to
a warm solution of Li(3,5-Me2C5H3BNi-Pr2) (3.18 g, 15.1 mmol)
in DME (100 mL). The reaction mixture was stirred and heated
to reflux temperature. It slowly turned yellow. After 24 h it was
filtered through a frit covered with silica (4.5 cm layer) and further
eluted with DME (3 × 10 mL). The volatiles were removed from
the filtrate in vacuum. Pentane (50 mL) was then added to the
residue. After stirring the mixture for 1 h the solid product was
collected by filtration, washed with pentane (3 × 50 mL), and dried
under vacuum to give Li·6·2DME (6.70 g, 78%) as a pale yellow
solid; mp 102–103 ◦C, insoluble in pentane, soluble in toluene,
DME and THF.
Synthesis of [Hg{Mo(g5-3,5-Me2C5H3BNi-Pr2)(CO)3}Cl] (Hg–
Mo) (11). Solid HgCl2 (0.50 g, 1.84 mmol) was added to a
suspension of Li·6·2DME (0.95 g, 1.66 mmol) in toluene (40 mL).
After the mixture was stirred for 2 h, the resulting dark yellow
suspension was filtered through a frit covered with silica (4 cm
layer) and further eluted with toluene (2 × 20 mL) in order to
achieve complete extraction. After removal of the volatiles the
yellow residue was triturated and washed with pentane (5 × 3 mL).
It was then recrystallized from a small amount of toluene at
−30 ◦C to give, after drying under vacuum, 11 (0.88 g, 85%) as a
bright yellow crystalline solid; mp 167–168 ◦C (decomp.), soluble
in toluene and insoluble in pentane.
Data for Li·6·2DME. Anal. Calc. for C24H43BLiMoNO7: C,
1
50.46; H, 7.59; N, 2.45. Found: C, 50.56; H, 7.10; N, 2.56%. H
Anal. Calc. for C16H23BClHgMoNO3: C, 30.99; H, 3.74; N, 2.26.
Found: C, 30.89; H, 3.71; N, 2.18%. 1H NMR (C6D6): d 4.84 (br s,
NMR (THF-d8): d 4.69 (t, 1H, H-4), 3.81 (d, 2H, H-2/6, 4J24 = 1.5
Hz), 2.02 (s, 6H, Me-3/5); Ni-Pr2: 3.52 (sept, 2H, NCH), 1.17 (d,
12H, Me, 3J = 6.8 Hz; DME: 3.43 (s, 8H, CH2), 3.27 (s, 12H, Me).
4
couplings not resolved, 1H, H-4), 4.18 (d, 2H, H-2/6, J24 = 1.2
Hz), 1.39 (s, 6H, Me-3/5); Ni-Pr2: 3.29 (sept, 2H, NCH), 1.18 and
1
3
1
13C{ H} NMR (THF-d8): d 232.9 (CO), 125.1 (C-3/5), 84.3 (br,
1.11 (2d, 2 × 6 H, J = 6.8 Hz). 13C{ H} NMR (C6D6): d 221.7
(CO), 123.3 (C-3/5), 85.9 (C-4), 84.7 (br, C-2/6), 23.7 (3-/5-Me);
Ni-Pr2: 46.5 (NCH), 22.5 and 21.6 (Me). 11B NMR (C6D6): d 24.3.
IR (KBr): m(CO): 2020s, 1940s, 1922s cm−1.
C-2/6), 81.0 (C-4), 25.7 (Me-3/5); Ni-Pr2: 46.0 (NCH), 22.8 (Me);
DME: 72.6 (OCH2), 58.7 (OMe). 11B NMR (THF-d8): d 24.3. IR
(KBr): m(CO): 1916s, 1793s, 1747s cm−1.
2956 | Dalton Trans., 2006, 2950–2958
This journal is
The Royal Society of Chemistry 2006
©
Auvray, Nicolas
