G. P. M. van Klink, T. Nomoto, M. Lutz, A. L. Spek, O. S. Akkerman, F. Bickelhaupt
FULL PAPER
a Bruker AC 200 spectrometer (1H NMR: δ ϭ 200.1 MHz; 13C 4.47 [s, 4 H, ArCH2 (side-on)], 7.10Ϫ7.14 [m, ArH(4) (rotaxane)],
NMR: δ ϭ 50.32 MHz) or on a Bruker MSL 400 spectrometer
(1H NMR: δ ϭ 400.1 MHz; 13C NMR: δ ϭ 100.6 MHz). HRMS
measurements were performed on a Finnigan MAT 90 spec-
trometer (direct inlet). Caution: Organomercury compounds are
poisonous!
7.22 [t, J ϭ 7.1 Hz, ArH(3.5)], 7.80 [d, 3J ϭ 6.4 Hz, ArH(2.6)], 7.74
[s, 1 H, xylyl-H (side-on)], 8.60 [s, 1 H, xylyl-H (rotaxane)] ppm.
The other signals coincide with those of 9a.
9c: 1H NMR {[D8]toluene, 200.1 MHz, ref. C6D5CD2H: δ ϭ
2.03 ppm}: δ ϭ 4.09 (s, 8 H, ArCH2), 8.56 (s, 2 H, xylyl-H) ppm.
The other signals coincide with those of 9a and 9b.
Diphenylmagnesium: Diphenylmercury (6.39 g, 18 mmol) was
stirred with doubly sublimed magnesium (4.37 g, 180 mmol) in di-
ethyl ether (180 mL) in a fully sealed glass system for three weeks.
After the magnesium amalgam had settled, the clear solution was
decanted into a second vessel, and an aliquot of known volume
Reaction of 8 with One Molar Equivalent of Diphenylmagnesium:
Solutions of 8 (7.55 mg, 0.0147 mmol) in diethyl ether (2 mL) and
of diphenylmagnesium [0.015 mmol in diethyl ether (4 mL)] were
combined in a fully sealed glass system. After formation of a white
was hydrolyzed and titrated (OHϪ and Mg2ϩ [19]
concentration of diphenylmagnesium.
)
to establish the suspension, the diethyl ether was distilled off and replaced by tolu-
ene (10 mL). The clear supernatant was decanted and analyzed by
titration and by 1H NMR spectroscopy in [D8]toluene, which
Bis(p-tert-butylphenyl)magnesium: In a fully sealed glass system,
bis(p-tert-butylphenyl)mercury (9.34 g, 20 mmol) was stirred with
doubly sublimed magnesium (4.86 g, 200 mmol) in diethyl ether
(200 mL) for three weeks. After settling of the magnesium amal-
gam, the clear solution was decanted into a second vessel, and an
aliquot of known volume was hydrolyzed and titrated (OHϪ and
showed that only the starting material 8 was present. The pale
brown precipitate was dissolved in [D8]toluene and showed essen-
1
tially the same H NMR spectrum as that obtained in the reaction
of 8 with two equivalents of Ph2Mg, but with the products 9a and
1
9b in a ratio of 55:45. H NMR signals of 9c were not detected.
Mg2ϩ [19]
)
to establish the concentration of bis(p-tert-butylphe-
Reaction of 8 with Two Molar Equivalents of (p-tBuC6H4)2Mg: A
solution of (p-tBuC6H4)2Mg (0.085 mmol) in diethyl ether (1 mL)
was added to 8 (0.02167 g, 0.0421 mmol) in a fully sealed glass
system, to give a clear yellow solution. After 10 min, a finely di-
vided powder started to precipitate. After 2.5 h, the diethyl ether
was distilled off, and toluene (10 mL) was added to the residue.
The mixture was heated, but a clear solution was not obtained.
Several attempts to crystallize the white residue in order to obtain
suitable crystals for an X-ray crystal structure determination were
nyl)magnesium.
Reaction of 8 with Two Molar Equivalents of Diphenylmagnesium:
Solutions of 8[18] [7.55 mg, 0.0147 mmol in diethyl ether (2 mL)]
and of diphenylmagnesium [0.03 mmol in diethyl ether (8 mL)]
were combined in a fully sealed glass system. Within 15 min, the
clear yellow solution decolorized, and a white precipitate was
formed. After heating at 40 °C for 2 h, the clear supernatant was
carefully decanted. The diethyl ether mother liquor was hydrolyzed,
and the aqueous phase was titrated (OHϪ and Mg2ϩ).[19] This indi-
cated that more than 90% of the Ph2Mg was contained in the pre-
cipitate. This titration sample was carefully extracted with benzene.
The organic layers were combined, dried (MgSO4), filtered, and the
solvents evaporated to dryness. 1H NMR spectroscopy revealed no
signals that could be ascribed to starting material 8. The solid reac-
tion product obtained by decantation was dried by pumping under
high vacuum, and toluene (10 mL) was then added, upon which
most of the solid dissolved. From the supernatant, a sample was
taken for characterization by 1H NMR spectroscopy in [D8]toluene.
To quantify the effects of complexation on the chemical shifts of
the crown ether, a reference spectrum of pure 8 was measured under
identical conditions. 1H NMR spectroscopy revealed that signals
of the free crown ether 8 were absent. Assignment of all signals was
not possible due to overlap and the complexity of the spectrum.
Integration of the benzylic proton signals was used to determine
the following relative yields: 9a (55.9%), 9b (43.2%), and 9c (0.9%).
8: 1H NMR {[D8]toluene, 200.1 MHz, ref. C6D5CD2H: δ ϭ
2.03 ppm}: δ ϭ 3.43Ϫ3.51 (br. s, 32 H, CH2), 4.57 (s, 8 H, ArCH2),
1
unsuccessful. A sample was analyzed by H NMR spectroscopy in
[D8]toluene. Assignment of all signals was not possible due to the
complex nature of the spectrum. The two complexes in a mixture
of 10a and 10b were present in a ratio of 64.5:35.5. In this case, only
a faint signal of the double rotaxane complex 10c was discernible at
δ ϭ 4.08 ppm.
10a: 1H NMR {[D8]toluene, 400.1 MHz, ref. C6D5CD2H: δ ϭ
2.03 ppm}: δ ϭ 1.36 (s, 36 H, tBu), 3.37Ϫ3.45 (m, 32 H, CH2),
4.52 (s, 8 H, ArCH2), 7.45 [d, AB, 3J ϭ 8 Hz, 8 H, ArH(3.5)], 7.89
3
(s, 2 H, xylyl-H), 8.11 [d, BA, J ϭ 8 Hz, 8 H, ArH(2.6)].
10b: 1H NMR {[D8]toluene, 400.1 MHz, ref. C6D5CD2H: δ ϭ
2.03 ppm}: δ ϭ 1.39 (s, 18 H, tBu) 2.93Ϫ2.99 (m, 4 H, CH2),
3.11Ϫ3.12 (m, 4 H, CH2), 3.17Ϫ3.23 (m, 4 H, CH2), 3.32Ϫ3.36
(m, 4 H, CH2), 4.23 [s, 4 H, ArCH2 (rotaxane)], 4.49 [s, 4 H, ArCH2
3
(side-on)], 7.27 [d, AB, J ϭ 7.9 Hz, 4 H, ArH(3.5)], 7.77 [d, BA,
3J ϭ 7.9 Hz, 4 H, ArH(2.6)], 7.89 [s, 1 H, xylyl-H (side-on)], 8.67
[s, 1 H, xylyl-H (rotaxane)] ppm. The other signals overlap with
those of 10a.
Reaction of 8 with Two Molar Equivalents of Hg(SCN)2: A solution
7.93 (s, 2 H, ArH) ppm. 13C NMR {[D8]toluene, 50.32 MHz, ref. of Hg(SCN)2 (0.06335 g, 0.200 mmol) in acetone (2 mL) was added
C6D5CD3: δ ϭ 20.40 ppm}: δ ϭ 69.61 (tt, 1J ϭ 139.9, 2J ϭ 4.2 Hz, to a solution of 8 (0.05143 g, 0.100 mmol) in acetone (2 mL).
4C, CH2O), 71.00 (t, 1J ϭ 141.9 Hz, 4C, CH2O), 71.05 (t, 1J ϭ
Within a few minutes, a white precipitate formed, which was sepa-
139.9 Hz, 4C, CH2O), 71.18 (td, 1J ϭ 140.4, 3J ϭ 3.8 Hz, 4C, rated by filtration and characterized by H NMR spectroscopy as
1
1
ArCH2), 71.46 (tt, J ϭ 140.0, 2J ϭ 2.5 Hz, 4C, CH2O), 128.22 (d, [8·{Hg(SCN)2}2] (11); this assignment was confirmed by the X-ray
1J ϭ 163.8 Hz, 2C, aryl-CH), 135.50 (d, 2J ϭ 3.5 Hz, 2C, aryl-
crystal structure determination.
C) ppm.
11: 1H NMR (CDCl3, 200.1 MHz, ref. CHCl3: δ ϭ 7.27 ppm): δ ϭ
9a: 1H NMR {[D8]toluene, 200.1 MHz, ref. C6D5CD2H: δ ϭ 3.67 (s br., 24 H, CH2), 3.82 (m, 8 H, CH2), 4.78 (s, 8 H, ArCH2),
2.03 ppm}: δ ϭ 3.38 (s br., 16 H, CH2), 3.41 (m, 16 H, CH2), 4.50
8.05 (s, 2 H, ArH) ppm. 13C NMR (CDCl3, 100.6 MHz, ref.
(s, 8 H, ArCH2), 7.24Ϫ7.26 [m, ArH(4)], 7.34 [t br., J ϭ 6.9 Hz, CDCl3: δ ϭ 77.00 ppm): δ ϭ 69.20 (t, 1J ϭ 145.6 Hz, 4C, CH2),
ArH(3.5)], 7.83 (s, 2 H, xylyl-H), 8.11 [d br., 3J ϭ 6.2 Hz, 69.42 (t, 1J ϭ 139.7 Hz, 4C, CH2), 69.74 (t, 1J ϭ 142.7 Hz, 4C,
1
1
ArH(2.6)] ppm.
9b: 1H NMR {[D8]toluene, 200.1 MHz, ref. C6D5CD2H: δ ϭ 4C, ArCH2), 135.72 (d, J ϭ 44.8 Hz, 2C, aryl-CH), 137.69 (br. s,
2.03 ppm}: δ ϭ 2.94Ϫ3.01 (m, 4 H, CH2), 3.12Ϫ3.16 (m, 4 H, 4C, aryl-C) ppm. Contrary to 12 (vide infra), 11 was not volatile
CH2), 3.30Ϫ3.34 (m, 4 H, CH2), 4.20 [s, 4 H, ArCH2 (rotaxane)], under DCI conditions.
CH2), 69.84 (t, J ϭ 141.9 Hz, 4C, CH2), 71.06 (t, J ϭ 140.3 Hz,
2
158
2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2004, 154Ϫ159