Group 13 NHC Analogues Complexed with Metal Carbonyl Fragments
4
.12 [br. m, 8 H, CH(CH
3
)
2
, NCH], 7.02–7.38 (br. m, 12 H, ArH)
Conclusions
1
3
1
ppm.
C{ H} NMR (100.6 MHz, C , 298 K): δ = 24.0
6 6
D
A series of complexes of four-membered gallium(I) and [CH(CH ) ], 25.3 (CH ), 26.5 (CH ), 27.0 [CH(CH ) ], 28.1
3
2
2
2
3 2
indium(I) heterocycles with transition metal carbonyl frag- [CH(CH
3
)
2
], 35.0 (CH
2
), 60.0 (NCH), 124.3, 126.0, 139.7, 145.4
), 207.5 (CO) ppm. IR (Nujol): ν˜ =
031 (s, CO), 1992 (s, CO), 1955 (s, br., CO), 1937 (s, br., CO)
ments have been prepared. As in previous studies, these het- (ArC), 167.5, (backbone CN
3
2
erocycles have been shown to act as σ-donor ligands, but
–
1
+
cm . MS (EI, 70 eV): m/z (%) = 544.5 (100) [GisoH ].
they appear not to be as nucleophilic as group 13 diyls,
:
MR (M = Ga or In). Moreover, the indium heterocycle is [Ru(CO) (PPh ) {Ga(Giso)}] (5): A solution of [Ga(Giso)] (90 mg,
2 3 2
a weaker σ-donor than its gallium counterpart. A compari- 0.15 mmol) in toluene (7 mL) was added to a stirred slurry of
son of the structural and spectroscopic properties of a gal-
2 3 3
[Ru(CO) (PPh ) ] (139 mg, 0.15 mmol) in toluene (5 mL) at –80 °C
over 10 min. The reaction mixture was warmed to room tempera-
ture overnight, with constant stirring. A change in solution color
to orange was noted. Volatiles were removed in vacuo, and the
residue was extracted with hexane (8 mL), giving an orange solu-
tion. Concentration of the solution to ca. 5 mL and subsequent
lium–iron complex, [Fe(CO) {Ga(Giso)}], with those of re-
4
lated complexes led to the conclusion that there is little
FeǞGa π-bonding in this compound, and therefore, that
the gallium heterocycle is a relatively poor π-acid. We con-
tinue to explore the coordination chemistry of low-oxi-
dation-state group 13 heterocycles.
cooling to –30 °C overnight yielded red-orange crystals of 5 (yield
1
8
7 mg, 45%); m.p. Ͼ 150 °C (dec.). H NMR (400.13 MHz, 300 K,
C
6
D
6
): δ = 0.83 (m, 8 H, CH
2
), 1.34–1.57 (m, 12 H, CH
HH ≈ 6.8 Hz, 24 H, CH(CH ], 3.77 (m, 2 H,
= 6.8 Hz, 4 H, CH(CH ) ], 6.85–8.01 (m,
2
), 1.52 [2
3
overlapping d,
CHN), 4.02 [sept, J
J
3 2
)
3
Experimental Section
HH
1
3 2
3
1
36 H, ArH) ppm. P{ H} NMR (121.65 MHz, 300 K, C
6
D
6
): δ =
General: All manipulations were carried out by using standard
Schlenk and glove-box techniques under high-purity argon. Hex-
ane and toluene were distilled from Na/K alloy under dinitrogen.
Infrared spectra were obtained as Nujol mulls by using a Perkin–
Elmer 1600 series FTIR spectrometer with NaCl plates. NMR
spectroscopy was carried out by using either Jeol Eclipse 300 or
Bruker DPX 400 spectrometers. Mass spectra were obtained from
the EPSRC Mass Spectrometry Service, Swansea. The microanaly-
sis was carried out by Medac Ltd. UK. Melting points were deter-
mined in sealed glass capillaries under argon and are uncorrected.
–
1
56.85 ppm. IR (Nujol): ν˜ = 1948 (s, CO), 1884 (s, CO) cm . MS
+
(
EI, 70 eV): m/z (%) = 544.5 (100) [GisoH ].
[Ru(CO) (PPh {In(Giso)}] (6): A solution of [In(Giso)] (0.10 g,
0.15 mmol) in toluene (5 mL) was added to a stirred slurry of
[Ru(CO) (PPh ] (143 mg, 0.15 mmol) in toluene (20 mL) at
2
3 2
)
2
3 3
)
–80 °C over 5 min. The reaction mixture was warmed to room tem-
perature overnight, yielding an orange solution. Volatiles were re-
moved in vacuo, and the red/orange residue was extracted with
toluene (8 mL). Concentration of the extract to ca. 5 mL and sub-
[
12]
[12]
[27]
[:Ga(Giso)], [:In(Giso)] and [Ru(CO)
2
(PPh
3
)
3
]
were synthe-
sequent slow cooling to –30 °C overnight afforded red/orange crys-
1
sized by literature procedures. All other starting materials were pur-
chased and used as received.
tals of
(400.13 MHz, 300 K, C
6
[yield 145 mg (vacuum-dried), 72%].
H
NMR
), 1.37 [d,
], 1.43–1.65 (m, 12 H, Cy-CH ),
], 3.73 (m, 2 H, CHN),
], 6.85–8.04 (m, 36 H,
): δ = 59.69
ppm. IR (Nujol): ν˜ = 1937 (s, CO), 1869 (s, CO) cm . MS: m/z (%)
6
6 2
D ): δ = 0.87 (m, 8 H, Cy-CH
3
J
HH = 6.8 Hz, 12 H, CH(CH
3
)
2
2
[
0
(
Fe(CO)
.245 mmol) in toluene (10 mL) was added to a slurry of Fe
CO) (0.10 g, 0.275 mmol) in toluene (5 mL) at –80 °C. The mix-
4
{Ga(Giso)}] (3): A solution of [Ga(Giso)] (0.15 g,
1
3
.49 [d, 3JHH = 6.8 Hz, 12 H, CH(CH
3
)
2
2
-
3
.91 [sept, JHH = 6.8 Hz, 4 H, CH(CH
3
)
2
9
3
1
1
6 6
ArH) ppm. P{ H} NMR (121.65 MHz, 300 K, C D
ture was slowly warmed to room temperature and stirred overnight.
All volatiles were removed in vacuo, and the residue was extracted
into hexane (15 mL). The extract was concentrated to ca. 7 mL and
–
1
+
=
544.5 (100) [GisoH ]. C82
1 3 2 2
H94In N O P Ru (6·toluene) (1431.49):
calcd. C 68.80, H 6.62, N 2.94; found C 68.27, H 6.43, N 2.86.
placed at –30 °C for 20 h to afford pale yellow crystals of 3 (yield
1
0
C
CH
3
.11 g, 58%). M.p. Ͼ 180 °C (dec.). H NMR (400 MHz, 296 K,
[CpMo(CO) {[(Giso)Ga] OH}] (7): A few crystals of compound 7
were obtained from a reaction of [Ga(Giso)] with 0.5 equiv. of
], [{CpMo(CO)
] in toluene. M.p. 220–225 °C (dec.). 1H NMR
and NCH], 7.05–7.30 (br. m, 6
(400 MHz, 296 K, C ): δ = 0.28–0.83 (m, 12 H, CH ), 0.90–1.89
2
2
6
D
6
): δ = 0.69–0.84 (br. m, 6 H, CH
), 1.35 [br. d, 12 H, CH(CH ], 1.67 [br. d, 12 H, CH(CH
.50–3.80 [br. m, 6 H, CH(CH
2
), 1.30–1.90 (br. m, 14 H,
)
2
3
)
2
2 2
}
2
3
)
2
6
D
6
2
3
13
1
H, ArH) ppm. C{ H} NMR (100.6 MHz, C , 298 K): δ = 22.6
[m, 77 H CH(CH , CH , OH], 3.38–3.60 [m, 12 H, NCH,
), 27.1 [CH(CH
], 29.7 CH(CH ], 4.44 (s, 5 H, C ), 6.79–7.23 (m, 12 H, ArH) ppm.
), 61.0 (NCH), 124.6, 127.4, 139.2, 144.7 IR (Nujol): ν˜ = 3635 (OH), 1901 (s, CO), 1837 (s, CO) cm . MS
D
6
3
)
2
2
6
[
[
CH(CH
CH(CH
3
)
)
2
], 25.7 (CH
], 35.5 (CH
2
), 26.8 (CH
2
3
)
2
3
)
2
5 5
H
–
1
3
2
2
+
+
(
ArC), 170.1 (backbone CN
3
), 215.7 (CO) ppm. IR (Nujol): ν˜ =
(EI, 70 eV): m/z (%) = 1460.7 (2) [MH ], 544.5 (100) [GisoH ].
2
026 (s, CO), 1970 (s, CO), 1945 (s, br., CO), 1916 (s, br., CO)
X-ray Single-Crystal Structural Analyses: Crystals of 3, 4,
–1
+
+
cm . MS (EI 70 eV): m/z (%) = 779.2 (2) [M ], 751.2 (3) [M
CO], 695.2 (8) [M – 3 CO], 667.3 (100) [M – 4 CO]. EI MS:
calcd. for [M ] 779.2871; found 779.2872.
–
6·(toluene)1.5 and 7·(hexane)0.25 suitable for X-ray structural deter-
+
+
mination were mounted in silicone oil. Crystallographic measure-
+
ments were made by using a Nonius Kappa CCD diffractometer.
2
[(CO)
3
Co{µ-Ga(Giso)}
2
Co(CO)
3
] (4): A solution of [Ga(Giso)] The structures were solved by direct methods and refined on F by
full-matrix least squares (SHELX97)[ using all unique data. Two
31]
(0.16 g, 0.261 mmol) in toluene (10 mL) was added to a solution of
Co
2
(CO)
8
(0.10 g, 0.288 mmol) in toluene (5 mL) at –80 °C. The crystallographically independent molecules were refined in the
resultant mixture was warmed to room temperature and stirred for
h. All volatiles were then removed in vacuo and the residue ex-
tracted with hexane (10 mL). The extract was concentrated to ca.
asymmetric unit of 3. There are no significant geometric differences
between them. The absolute structure parameter for the structure
of 7 is 0.002(12). All non-hydrogen atoms are anisotropic with hy-
drogen atoms included in calculated positions (riding model). Crys-
tal data, details of data collections and refinement are given in
2
8
4
2
7
mL and placed at –30 °C for 1 week to afford yellow crystals of
(yield 30 mg, 15%). M.p. 180–190 °C (dec.). H NMR (400 MHz,
1
96 K, C
6
D
6
): δ = 0.68–0.98 (br. m, 12 H, CH
2
), 1.22–1.93 [br. m,
Table 2. CCDC-730325 (3), -730326 (4), -730327 [6·(toluene)1.5]
6 H, CH(CH
3
)
2
, CH ], 3.62–3.80 [br. m, 4 H, CH(CH )
2
3 2
], 3.92– and -730328 [7·(hexane)0.25] contain the supplementary crystallo-
Eur. J. Inorg. Chem. 2009, 3593–3599
© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
3597