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Q.-X. Liu et al. / Inorganica Chimica Acta 376 (2011) 437–445
reported in ppm relative to the internal standard TMS for both 1H
and 13C NMR. J values are given in Hertz. Elemental analyses were
measured using a Perkin–Elmer 2400C Elemental Analyzer. The
luminescent spectra were conducted on a Cary Eclipse fluorescence
spectrophotometer. GC analysis was carried out using a Shimadzu
GC-17A equipped with an integrator (C-R8A) with a capillary col-
umn (CBP-1 or CBP-5, 0.25 mm i.d. ꢂ 35 m).
Found: C, 39.43; H, 2.64; N, 8.64%. 1H NMR (400 MHZ, [D6]DMSO):
d 2.09 (s, 2H, CH2CN), 5.92 (s, 2H, CH2), 6.06 (s, 2H, CH2), 7.23 (m,
2H, PhH or PyH), 7.48 (m, 4H, PhH or PyH), 7.68 (m, 3H, PhH or
PyH), 8.22 (d, J = 4.8, 2H, PhH or PyH), 8.58 (d, J = 4.0, 2H, PhH or
PyH). 13C NMR (100 MHZ [D6]DMSO): d 185.0 (Ccarbene), 153.5,
150.3, 138.9, 135.7, 133.9, 129.4, 127.5, 126.4, 124.6 (PhC or
PyC), 113.7 (CN), 52.5 (CH2), 52.3 (CH2), 51.7 (CH2CN). IR (KBr):
m
CN, 2150 cmꢀ1
.
2.2. Preparation of [1,3-Diethylbimidazolium][HgI4] (1)
2.6. Preparation of {[(1-picolyl-3-npropylbimy)2Hg][Hg2I6]}n (5)
A
suspension of precursor 1,3-diethylbimidazolium iodide
(0.200 g, 0.499 mmol) and mercury (II) iodide (0.100 g,
0.499 mmol) in acetonitrile (30 mL) was stirred for 24 h at 60 °C,
and a pale yellow solution was formed. The resulting solution
was filtered and concentrated to 8 mL, and Et2O (5 mL) was added
to precipitate a pale yellow powder of 1. Yield: 0.275 g (62%). Anal.
Calc. for C22H30HgI4N4: C, 24.96; H, 2.86; N, 5.29. Found: C, 24.78;
H, 2.64; N, 5.42%. 1H NMR (400 MHZ [D6]DMSO): d = 1.52 (t, J = 3.6,
6H, CH3), 4.49 (m, 4H, CH2), 7.69 (m, 2H, PhH), 8.09 (m, 2H, PhH),
9.80 (s, 2H, 2-benzimiH). 13C NMR (100 MHZ, [D6]DMSO):
d = 142.2 (NCN), 131.6, 131.4, 127.0 and 114.1 (PhC), 47.0 (NCH2),
14.6 (CCH3).
This compound was prepared in a manner analogous to that for
4. Yield: 0.210 g (67%). M.p.: 234–236 °C. Anal. Calc. for
32H34Hg3I6N6: C, 20.60; H, 1.84; N, 4.50. Found: C, 20.73; H,
C
1.76; N, 4.67%. 1H NMR (400 MHZ, [D6]DMSO): d = 0.86 (t, J = 3.6,
6H, CH3), 1.93 (m, 4H, CH2), 4.70 (t, J = 3.6, 4H, CH2), 6.13 (s, 4H,
CH2), 7.42 (t, J = 2.8, 2H, PhH or PyH), 7.70 (m, 4H, PhH or PyH),
7.96 (m, 4H, PhH or PyH), 8.10 (d, J = 3.8, 2H, PhH or PyH), 8.30
(d, J = 2.8, 2H, PhH or PyH), 8.41 (d, J = 2.8, 2H, PhH or PyH). 13C
NMR (100 MHZ [D6]DMSO): d = 181.5 (Ccarbene), 153.4, 150.3,
139.3, 133.5, 133.0, 126.6, 124.5, 124.2, 114.0 and 113.1 (PhC or
PyC), 51.9 (CH2), 50.7 (CH2), 23.6 (CH2), 11.3 (CH3).
2.3. Preparation of [(1,3-diethylbimy)6Ag4I3]I (2)
2.7. Preparation of [(1,3-dipicolylbimy)PdCl]Cl (6)
Silver(I) oxide (0.168 g, 0.726 mmol) was added to a dichloro-
methane (30 mL) solution of 1,3-diethylbimidazolium iodide
(0.200 g, 0.499 mmol) and the suspension solution was stirred for
24 h under refluxing. The resulting solution was filtered and con-
centrated to 10 mL, and Et2O (5 mL) was added to precipitate a
white powder. Isolation by filtration yields 2. Yield: 0.127 g
(58%). M.p.: 198–200 °C. Anal. Calc. for C66H84Ag4I4N12: C, 39.94;
H, 4.27; N, 8.47. Found: C, 39.64; H, 4.63; N, 8.86%. 1H NMR
(400 MHZ [D6]DMSO): d = 1.53 (t, J = 3.6, 36H, CH3), 4.62 (q,
J = 3.6, 24H, CH2), 7.50 (m, 12H, PhH), 7.89 (m, 12H, PhH). 13C
NMR (100 MHZ, [D6]DMSO): d = 133.4, 124.5 and 112.5 (PhC),
44.2 (CH2), 16.6 (CH3). The carbene carbon was not observed.
Silver oxide (0.052 g, 0.22 mmol) was added to a solution
of 1,3-dipicolylbenzimidazolium hexafluorophosphate (0.200 g,
0.45 mmol) in dichloromethane (10 mL) and acetonitrile (20 mL),
and the suspension solution was stirred for 24 h under refluxing.
The resulting solution was filtered, then Pd(CH3CN)2Cl2 (0.119 g,
0.46 mmol) was added to above solution. The suspension solution
was stirred for 24 h under refluxing. The resulting solution was fil-
tered and concentrated to 10 mL, and Et2O (5 mL) was added to
precipitate a brown powder. Isolation by filtration yields 6. Yield:
0.170 g (82%). M.p.: 320–322 °C. Anal. Calc. for C19H16Cl2N4Pd: C,
47.77; H, 3.38; N, 11.73. Found: C, 47.43; H, 3.54; N, 11.46%. 1H
NMR (400 MHZ [D6]DMSO): d 6.06 (s, 4H, CH2), 7.57 (m, 2H,
PhH), 7.72 (m, 2H, PhH), 8.07 (m, 4H, PyH), 8.29 (m, 2H, PyH),
9.42 (m, 2H, PyH). 13C NMR (100 MHZ [D6]DMSO): d 160.5
(Ccarbene), 156.3, 153.4, 141.5, 132.8, 127.2, 125.5, 124.7, 112.4
(PhC or PyC), 51.1 (CH2).
2.4. Preparation of [(1-benzyl-3-picolylbimy)Ag2Br2]n (3)
This compound was prepared in a manner analogous to that for
2. Yield: 0.187 g (72%). M.p.: 240–242 °C. Anal. Calc. for
C
40H34Ag2Br1.22Cl0.78N6: C, 51.13; H, 3.65; N, 8.94. Found: C,
2.8. General procedure for the Suzuki–Miyaura cross-coupling reaction
50.92; H, 3.18; N, 8.52%. 1H NMR (400 MHZ, [D6]DMSO): d = 5.76
(s, 2H, CH2), 5.86 (s, 2H, CH2), 7.30 (m, 8H, PhH or PyH), 7.39 (m,
8H, PhH or PyH), 7.45 (m, 2H, PhH or PyH), 7.80 (m, 6H, PhH or
PyH), 8.46 (d, J = 2.2, 2H, PhH or PyH). 13C NMR (100 MHZ
[D6]DMSO): d = 206.9 (Ccarbene), 155.7, 150.0, 137.8, 136.7, 134.3,
133.7, 129.2, 128.5, 127.8, 124.6, 123.7, 122.6, 112.9 (PhC or
PyC), 53.8 (CH2), 52.3 (CH2).
In a typical reaction, aryl halide (0.5 mmol), phenylboronic acid
(0.6 mmol), base (1.2 mmol), and Pd–NHC complex 6 (0.2 mol %) in
organic solvent (2.5 mL) and water (0.5 mL if needed) was stirred
at 60 °C in air. After the desired reaction time, the reaction was
stopped, and water (20 mL) was added to the reaction mixture.
The mixture was extracted by diethyl ether (5 mL ꢂ 3), and the or-
ganic layer was washed with water (10 mL ꢂ 3) and dried over
anhydrous MgSO4. The solution was filtered. After the solvent of
filtrate was removed, n-hexane (2 mL) was added to the crude
product. The solution was analyzed by GC or separated by a col-
umn to get the product.
2.5. Preparation of [(1-benzyl-3-picolylbimy)HgI(CH2CN)]2 (4)
A suspension of KOtBu (0.112 g, 1.0 mmol), 1-benzyl-3-picolyl-
benzimidazolium hexafluorophosphate (0.200 g, 0.45 mmol) and
HgI2 (0.204 g, 0.45 mmol) in acetonitrile (20 mL) was refluxed for
24 h. A bright yellow solution was formed and the solvent was re-
moved by rotary evaporation. The water (30 mL) was added to the
residue. The solution was extracted with CH2Cl2 (3 ꢂ 20 mL), and
the extracting solution was dried over anhydrous MgSO4.The solu-
tion was concentrated to 10 mL, and Et2O (5 mL) was added to pre-
cipitate a pale yellow powder. Yield: 0.195 g (65%). M.p.: 172–
174 °C. Anal. Calc. for C22H19HgIN4: C, 39.62; H, 2.87; N, 8.40.
2.9. X-ray structure determinations
For complexes 1–6, selected single crystals were mounted on a
Bruker APEX II CCD diffractometer at 293(2) K with Mo K
a radia-
tion (k = 0.71073 Å) by scan mode. Data collection and reduction
x
were performed using the SMART and SAINT software [11] with frames
of 0.6° oscillation in the range of 1.8° < h < 25°. An empirical