Inorganic Chemistry
Article
of fresh medium was then added, and the resulting suspension was
pelleted in a 1.5 mL eppendorf by centrifuging for 5 min at 1200 rpm.
The pellets were resuspended in 500 μL of fresh medium, and a 50 μL
fraction was separated for cell counting after staining with Trypan
Blue. The suspension was centrifuged again. The medium was
removed, and 0.5 mL of concentrated aqua regia was added for
digestion overnight. The resulting solutions were diluted gravimetri-
cally with ultrapure water and analyzed by ICP-MS. Measurements
were performed by an ICP quadrupole mass spectrometer (Elan
DRC-e, PerkinElmer, Shelton, CT, USA) equipped with a standard
ICP torch, cross-flow nebulizer, nickel sampler, and skimmer cones
and DRC. PTFE vessels, micropipette tips, eppendorfs for digestion,
and polypropylene (PP) tubes were cleaned in 10% HNO3 overnight
and rinsed thoroughly with ultrapure water.
Cell Fluorescence Microscopy Study. The European Collection
of Cell Cultures was maintained in HEPES modified minimum
essential medium (DMEM) supplemented with 5% fetal bovine
serum, penicillin, and streptomycin. A549 cells were detached from
the plastic flask using trypsin-EDTA solution and suspended in an
excess volume of growth medium. A total of 300 μL of a
homogeneous cell suspension was then distributed into an μ-slide 8
well ibiTreat; the cells were allowed to attach for 24 h prior to the
addition of compounds. Then, 200 μL of culture medium was
removed, and 100 μL of a solution of the corresponding complexes
was added to the cells up to a final concentration of 5 or 25 μM. The
complexes were incubated with the cells for 4 or 24 h at 37 °C,
depending on the experiment. Thereafter, 50 μL of MitoTracker Red
or LysoTracker Red DND-99 was added up to a final concentration of
10 nM. They were incubated with the cells for 15 min (MitoTracker)
or 30 min (LysoTracker) at room temperature. Eventually, the
medium was replaced with fresh medium without phenol red.
Preparations were viewed using an Olympus FV10-i Oil type compact
confocal laser microscope using a ×10 or ×60 objective, with
excitation wavelengths at 405, 473, and 588 nm.
Synthesis of Complex 3. To a stirred solution of complex 1 (15
mg, 0.0294 mmol) and [AuClIPr] (36.6 mg, 0.589 mmol) in MeOH
(5 mL) was added a solution of KOH (3.87 mg, 0.0588 mmol) in
MeOH (3 mL). The mixture was stirred 24 h at room temperature
and then purified by alumina column chromatography employing
ether/MeOH (97:3 to 93:7). The product was obtained as a yellow
1
solid (yield 22.4 mg, 45%). H NMR (300 MHz, acetone-d6): δ 8.67
(dbr, J = 5.8 Hz, 2H, H6), 8.22 (dbr, J = 1.6 Hz, 2H, H3), 7.81 (s, 4H,
H10), 7.61 (t, J = 7.8 Hz, 4H, H14), 7.45 (d, J = 7.8 Hz, 8H, H13), 7.24
(dd, J = 5.8, 1.6 Hz, 2H, H5), 2.72 (t, J = 6.9 Hz, 4H, H15), 2.68 (t, J =
6.9 Hz, 4H, H15), 1.39 (d, J = 6.9 Hz, 24H, CH3), 1.27 (d, J = 6.9 Hz,
24H, CH3). 13C NMR (101 MHz, acetone-d6): δ 199.26 (s, CO),
191.08 (s, CO), 189.94 (s, 2C, C9), 156.34 (s, 2C, C2), 152.64 (s, 2C,
C6), 148.63 (s, 2C, C8), 146.68 (s, 4C, C12), 139.06 (s, 2C, C4),
135.40 (s, 4C, C11), 131.41 (s, 2C, C14), 129.78 (s, 2C, C5), 126.91
(s, 2C, C3), 125.32 (s, 4C, C10), 125.00 (s, 8C, C13), 101.18 (s, 2C,
C7), 24.91 (s, 8C, CH3), 24.13 (s, 8C, CH3). IR (υ, cm−1): 2111
(CC), 2016, 1911, 1888 (CO), 1603 (CAr=N).
Synthesis of Complex 4. To a suspension of complex 1 (40 mg,
0.078 mmol) and tert-butylisocyanide gold chloride (49.5 mg, 0.157
mmol) in MeOH (5 mL) was added a solution of KOH (10.3 mg,
0.157 mmol) in MeOH (1 mL), and the mixture was allowed to react
for 12 h at room temperature. The solvent was then evaporated and
the residue dissolved in DCM. After filtration over Celite, the volume
was reduced to 1−2 mL, and ether was added to precipitate complex
4 as a yellow solid (yield 64.5 mg, 77%). 1H NMR (400 MHz,
CDCl3): δ 8.81 (d, J = 5.8 Hz, 2H, H2), 8.04 (d, J = 1.6 Hz, 2H, H5),
7.38 (dd, J = 5.8, 1.6 Hz, 2H, H3), 1.60 (s, 18H, H11). 13C NMR (101
MHz, CDCl3): δ 197.52 (s, CO), 189.91 (s, CO), 155.37 (s, 2C, C6),
152.40 (s, 2C, C2), 137.34 (s, 2C, C9), 136.73 (s, 2C, C4), 129.58 (s,
2C, C3), 126.07 (s, 2C, C5), 99.50 (s, 2C, C7), 59.12 (s, 2C, C10),
29.94 (s, 6C, C11). IR (cm−1): υ 2984 (Csp3−H), υ 2231 (CN), υ
2119 (CC), υ 2016, 1887 (CO), υ 1603 (CArN).
Synthesis of Complex 5. To a stirred solution of 1 (1 equiv, 22.6
mg, 0.013 mmol) in acetonitrile (5 mL) was added AgOTf (1.1 equiv,
3.7 mg, 0.014 mmol), and the reaction mixture was allowed to react at
40 °C overnight. The suspension was then filtrated over Celite, and
the solvent was evaporated. The crude was washed with ether three
times to afford an orange solid corresponding to 5 (18.4 mg, 75%).
1H NMR (400 MHz, CD3CN): δ 8.64 (d, J = 5.8 Hz, 2H, H6), 8.11
(d, J = 1.6 Hz, 2H, H3), 7.64 (t, J = 7.8 Hz, 4H, H14), 7.54 (s, 4H,
H10), 7.46 (d, J = 7.8 Hz, 8H, H13), 7.28 (dd, J = 5.8, 1.6 Hz, 2H, H5),
2.62 (quint, J = 6.9 Hz, 8H, H15), 2.13 (s, 3H, H19), 1.37 (s, 12H,
CH3-IPr), 1.36 (s, 12H, CH3-IPr), 1.29 (s, 12H, CH3-IPr), 1.28 (s,
12H, CH3-IPr). 13C NMR (101 MHz, CD3CN): δ 189.34 (s, 2C, C9)
156.58 (s, 2C, C2), 153.84 (s, 2C, C6), 148.49 (s, C8), 147.01 (s, 8C,
C12), 139.47 (s, 2C, C4), 135.17 (s, 4C, C11), 131.66 (s, 4C, C14),
130.47 (s, 2C, C5), 127.54 (s, 2C, C3), 125.28 (s, 4C, C10), 125.17 (s,
8C, C13), 101.68 (s, 2C, C7), 29.63 (s, 8C, C15), 24.82 (s, 8C, CH3-
IPr), 23.99 (s, 8C, CH3-IPr). IR (cm−1): υ 2961 (Csp3−H), υ 2107
(CC), υ 2032, 1917 (CO), υ 1602 (CArN). MALDI: 1643.4.
Calcd M-NCCH3: 1643.5
Materials and Procedures. The starting material [Au(acac)-
(PPh3)],27 [Au(CNtBu)Cl],28 [AuCl(PPh3)],29 and [AuClIPr]30
were prepared according to literature procedures, and their
experimental data agree with those reported.27−30 All other starting
materials and solvents were purchased from commercial suppliers and
used as received unless otherwise stated.
Synthesis of Complex 1. 4,4′-Alkynyl-2,2′-bipyridine (LNN; 129
mg, 0.632 mmol) and [Re(CO)5Cl] (228.7 mg, 0.632 mmol) were
suspended in toluene (10 mL) and heated at 80 °C for 8 h. The
suspension was cooled to room temperature, and the solid was filtered
and then washed with a small amount of toluene and petroleum ether.
The compound was obtained as an orange solid (306.3 mg, 95%). 1H
NMR (400 MHz, CDCl3): δ 9.01 (d, J = 5.8 Hz, 2H, H6), 8.20 (sbr,
2H, H3), 7.55 (dd, J = 5.8, 1.7 Hz, 2H, H5), 3.65 (s, 2H, H8). 13C
NMR (101 MHz, CDCl3): δ 196.9 (s, CO), 190.3 (s, CO), 155.3 (s,
2C, C6), 153.2 (s, 2C, C2), 133.9 (s, 2C, C4), 129.6 (s, 2C, C3), 128.3
(s, 2C, C8), 125.7 (s, 2C, C5), 87.3 (s, 2C, C7). IR (υ, cm-1): 3222
(CC−H), 3056 (CAr−H), 2107 (CC), 2016, 1884 (CO), 1605
(CArN). HRMS (m/z): 532.9685 [M
− Cl + Na],
Synthesis of Complex 6. To a stirred solution of 1 (1 eq, 50 mg,
0.098 mmol) in acetonitrile (5 mL) was added AgOTf (1.1 eq, 27.8
mg, 0.108 mmol), and the reaction mixture was allowed to react
overnight. The suspension was then filtrated over Celite and
concentrated, and ether was added to precipitate a yellow solid
corresponding to 6 (49.6 mg, 76%). 1H NMR (400 MHz, CD3CN): δ
8.98 (dd, J = 5.8, 0.6 Hz, 1H, H6), 8.58 (d, J = 1.1 Hz, 1H, H3), 7.74
C17H8ClN2NaClO3Re (532.9664).
Synthesis of Complex 2. To a stirred solution of complex 1 (13
mg, 0.0255 mmol) in DCM (2.5 mL) was added [Au(acac)(PPh3)]
(28.2 mg, 0.051 mmol). After 3 h of stirring at room temperature, the
solvent was reduced to minimum volume, and petroleum ether was
added to afford a yellow solid (yield 28.6 mg, 79%).1H NMR (300
MHz, CD2Cl2): δ 8.78 (d, J = 5.8 Hz, 2H, H6), 8.10 (d, J = 1.7 Hz,
2H, H3), 7.63−7.45 (m, 30H, HAr, Ph), 7.41 (dd, J = 5.8, 1.6 Hz, 2H,
(dd, J = 5.8, 1.6 Hz, 1H, H5), 4.16 (s, 1H, H8), 2.05 (s, 3H, H10). 13
C
NMR (101 MHz, CD3CN): δ 156.93 (s, C2), 155.13 (s, C6), 135.75
(s, C4), 131.28 (s, C5), 128.14 (s, C3), 123.68 (s, C9), 89.28 (s, C8),
79.94 (s, C7), 3.99 (s, C10). IR (cm−1): υ 3202 (Csp−H), υ 2104
(CC), υ 2034, 1917 (CO), υ 1609 (CArN). HRMS (m/z):
516.0341 M+, C19H11N3O3Re (516.0353)
Synthesis of Complex 7. To a stirred solution of 6 (1 equiv, 20 mg,
0.03 mmol) in acetonitrile (5 mL) was added [Au(acac)PPh3] (2
equiv, 33.6 mg, 0.06 mmol) with a change in the color of the solution
from yellow to brown. After 3 h of reaction, the solution was filtered
over Celite and concentrated, and ether was added to precipitate a
H5). 13C NMR (75 MHz, CD2Cl2): δ 198.47 (s, CO), 155.85 (s, 2C,
2
C2), 152.76 (s, 2C, C6), 137.62 (s, 2C, C4), 134.86 (d, J
= 13.8
P−C
Hz, 12C, o-C, Ph), 132.38 (s, 12C, p-C, Ph), 129.99 (d, 1J P−C = 57.3
Hz, 6C, i-C, Ph), 129.86 (d, 2J P−C = 11.3 Hz, 12C, m-C, Ph), 129.86
(s, 2C, C5), 126.37 (s, 2C, C3), 110.60 (s, 1C, C8), 100.22 (s, 1C, C7).
31P NMR (121 MHz, CD2Cl2): δ 41.5 (s). IR (υ, cm−1): 3046 (CAr−
H), 2107 (CC), 1998, 1884 (CO), 1600 (CArN). MALDI-
HRMS (m/z): 1391.1089 [M−Cl], C53H36Au2N2O3P2Re
(1391.1090).
H
Inorg. Chem. XXXX, XXX, XXX−XXX