CHEMPLUSCHEM
FULL PAPERS
163.8, 160.5, 158.2, 155.3, 152.6, 136.5, 135.2, 125.1, 124.6, 122.0,
121.7, 62.7, 62.6, 14.5, 14.3 ppm; HRMS (ESI): m/z calcd for
C32H32Cl2N4O8NaRu [M+Na]+: 795.0533; found: 795.0531.
1.23 Hz, 1H), 7.95 (dd, J=8.19, 5.31 Hz, 1H), 7.89 (dd, J=5.81,
1.78 Hz, 1H), 7.86 (dd, J=5.86, 1.76 Hz, 1H), 7.83–7.66 (m, 9H),
7.61 (dd, J=8.66, 5.25 Hz, 1H), 7.47–7.41 (m, 3H), 6.77 (AA’ of
AA’BB’, 2H), 4.52–4.35 (m, 8H), 1.42–1.28 ppm (m, 12H); 13C NMR
(100 MHz, [D6]DMSO, 258C): d=163.46, 163.44, 163.37, 163.36,
159.13, 159.11, 157.29, 157.19, 157.06, 157.04, 154.28, 153.03,
152.92, 152.54, 152.48, 150.85, 149.99, 144.57, 144.54, 138.45,
138.41, 138.33, 137.78, 136.80, 136.17, 131.42, 131.08, 130.84,
130.81, 130.61, 130.56, 128.96, 128.74, 128.57, 127.52, 126.71,
126.65, 125.87, 125.48, 123.94, 123.90, 123.82, 122.26, 121.45,
119.53, 119.06, 115.36, 115.12, 62.34, 62.30, 62.27, 14.05, 14.03 ppm;
19F NMR (376 MHz, [D6]DMSO, 258C): d=ꢀ77.75 ppm; HRMS (ESI):
5a: Compound 3a (1.50 g, 4.80 mmol) and [Ru(bpy)2Cl2] (2.07 g,
4.00 mmol) in ethylene glycol (40 mL) were heated in a round-bot-
tomed flask at 1208C for 20 h. The reaction mixture was cooled to
RT before the addition of H2O (720 mL), which resulted in a clear
red solution. A solution of NaOTf (13.8 g, 10 mmol) in H2O (40 mL)
was added dropwise with stirring. The precipitate was collected by
filtration and washed with a small amount of cold H2O and large
amounts of diethyl ether and finally dried under vacuum to give
an orange powder (3.78 g, 92%). 1H NMR (400 MHz, [D6]DMSO,
258C): d=14.14 (brs, 1H), 10.11 (s, 1H), 9.09 (d, J=8.22 Hz, 2H),
8.88 (d, J=8.25 Hz, 2H), 8.84 (d, J=7.95 Hz, 2H), 8.22 (ddd, J=
8.02, 7.94, 1.50 Hz, 2H), 8.16 (AA’ of AA’BB’, 2H), 8.11 (ddd, J=7.91,
7.88, 1.48 Hz, 2H), 8.04 (dm, J=5.05 Hz, 2H), 7.91 (m, 2H), 7.84
(dm, J=5.71 Hz, 2H), 7.67–7.51 (m, 4H), 7.34 (ddd, J=7.20, 5.68,
1.26 Hz, 2H), 7.02 ppm (AA’ of AA’BB’, 2H); 13C NMR (100 MHz,
[D6]DMSO, 258C): d=159.64, 156.78, 156.56, 153.32, 151.44, 151.37,
149.76, 149.45, 144.99, 144.48, 137.93, 137.77, 136.87, 130.49,
130.30, 128.43, 127.87, 127.72, 127.15, 126.31, 126.05, 125.48,
124.44, 124.35, 122.27, 121.15, 120.38, 119.07, 115.96, 62.78 ppm;
19F NMR (376 MHz, [D6]DMSO, 258C): d=ꢀ77.75 ppm; HRMS (ESI):
m/z calcd for C39H27N8ORu [5aꢀ2OTfꢀH]+: 725.1346; found:
725.1362.
m/z calcd for C57H48N8O9Ru [5cꢀ2OTf]2+
: 545.1288; found:
545.1307.
6a: Compound 5a (1.0 g, 0.98 mmol) and hexamethylenetetramine
(2.74 g, 19.5 mmol) were added to a microwave tube. The vessel
was flushed with argon followed by the addition of TFA (6 mL) and
finally the tube was sealed. After heating for three days at 1108C,
4m HCl (30 mL) was added and the mixture was transferred to
a 500 mL E-flask and stirred at RT for 3 h. The pH was adjusted to
approximately three with an aqueous saturated solution of
NaHCO3 (ꢁ110 mL), resulting in a red and sticky fraction, which
was dissolved by successively adding small portions of H2O, vigo-
rous stirring and decantation. The resulting slightly cloudy red so-
lution was filtered and washed with H2O. In total, 200 mL of H2O
was added. An orange precipitate formed upon the addition of
NaOTf (3.36 g, 19.5 mmol) dissolved in water (6 mL). This suspen-
sion was left to stand overnight before final filtration and drying
under vacuum. The orange product, 6a (0.802 g, 78%; xTFA =0.904
and xOTf =1.096), appeared as a double salt with varying distribu-
tion of the triflate and trifluoroacetate anions, depending on the
batch (determined by 19F NMR spectroscopy). 1H NMR (400 MHz,
[D6]DMSO, 258C): d=14.64 (brs, 1H), 10.42 (s, 2H), 9.15 (m, 2H),
8.94 (s, 2H), 8.89 (d, J=8.22 Hz, 2H), 8.85 (d, J=7.98 Hz, 2H), 8.22
(t, J=7.82 Hz, 2H), 8.11 (t, J=8.03 Hz, 2H), 8.06 (d, J=5.20 Hz, 2H),
7.94 (m, 2H), 7.85 (d, J=5.27 Hz, 2H), 7.67–7.53 (m, 4H), 7.35 ppm
(t, J=6.76 Hz, 2H); 13C NMR (100 MHz, [D6]DMSO, 258C): d=
191.31, 164.13, 156.79, 156.55, 151.52, 151.38, 150.96, 149.87,
145.04, 137.96, 137.80, 133.86, 130.56, 127.88, 127.75, 124.95,
124.47, 124.39, 122.27, 120.76, 119.07 ppm; 19F NMR (376 MHz,
[D6]DMSO, 258C): d=ꢀ73.47, ꢀ77.75 ppm; HRMS (ESI): m/z calcd
for C41H27N8O3Ru [6aꢀOTfꢀTFAꢀH]+: 781.1244; found: 781.1246.
5b: Compounds 3a (0.262 g, 0.84 mmol) and 4b (0.541 g,
0.70 mmol) in EtOH (99%, 7 mL) were heated in a sealed tube at
1208C for 19 h. The reaction mixture was cooled to RT before dilu-
tion with H2O (126 mL) and the dropwise addition of an aqueous
solution (7 mL) containing NaOTf (2.41 g, 14 mmol). The formed
gel was heated at 1008C for 1 h with slow stirring and cooled to
RT with continued slow stirring, and then stored in the refrigerator
overnight. The product was collected by filtration, washed with
small amounts of cold water followed by a large amount of Et2O,
and finally dried in vacuum to yield an orange powder (0.88 g,
96%). 1H NMR (400 MHz, [D6]DMSO, 258C): d=14.13 (brs, 1H),
10.15 (s, 1H), 9.35 (d, J=1.83 Hz, 2H), 9.33 (d, J=1.77 Hz, 2H), 9.11
(m, 2H), 8.15 (AA’ of AA’BB’, 2H), 8.10 (d, J=5.96 Hz, 2H), 8.08 (dm,
J=4.77 Hz, 2H), 7.91 (brm, 2H), 7.88 (dd, J=5.83, 1.78 Hz, 2H),
7.81 (m, 2H), 7.73 (m, 2H), 7.03 (AA’ of AA’BB’, 2H), 4.46 (q, J=
7.05 Hz, 4H), 4.40 (q, J=7.11 Hz, 4H), 1.37 (t, J=7.12 Hz, 6H),
1.31 ppm (t, J=7.03 Hz, 6H); 13C NMR (100 MHz, [D6]DMSO, 258C):
d=163.47, 163.37, 159.73, 157.32, 157.06, 153.48, 153.00, 152.54,
138.40, 138.27, 138.17, 138.04, 131.04, 128.44, 126.69, 123.91,
123.84, 122.27, 120.31, 119.06, 116.00, 62.34, 62.26, 14.05,
13.98 ppm; 19F NMR (376 MHz, [D6]DMSO, 258C): d=ꢀ77.76 ppm;
HRMS (ESI): m/z calcd for C51H43N8O9Ru [5bꢀ2OTfꢀH]+: 1013.2191;
found: 1013.2189.
6b: TFA (3 mL) was added to an argon-flushed tube containing 5b
(0.656 g, 0.5 mmol) and hexamethylenetetramine (1.402 g,
10.0 mmol). The tube was sealed and heated at 1108C for 3 days.
4m HCl (15 mL) was added to the reaction mixture and the red so-
lution was quickly transferred to a 250 mL Erlenmeyer flask, and
within a few minutes a dark-red sticky fraction was formed. The re-
action mixture was stirred for another 3 h at RT before the pH was
adjusted to approximately three with a saturated aqueous solution
of NaHCO3 (ꢁ44 mL). With successive additions of small portions
of water, vigorous stirring and decantation, the sticky fraction of
water was dissolved. In total, 500 mL of water was used. This
slightly cloudy solution was filtered before the addition of a solu-
tion of NaOTf (1.720 g, 10.0 mmol) in water (5 mL), which resulted
in the formation of an orange precipitate. After keeping the sus-
pension in the refrigerator overnight, the powder was collected by
filtration, washed with a small amount of cold water and a large
amount of diethyl ether, and dried under vacuum to yield 6b
(0.479 g, 71%) as a double salt, in which xTFA =0.45 and xOTf =1.55.
1H NMR (400 MHz, [D6]DMSO, 258C): d=14.28 (brs, 1H), 10.37 (s,
2H), 9.35 (m, 2H), 9.32 (m, 2H), 9.15 (m, 2H), 8.74 (s, 2H), 8.10 (d,
5c: Compounds 3b (0.70 g, 1.80 mmol) and 4b (1.16 g, 1.50 mmol)
in EtOH (99%, 15 mL) were heated in a sealed tube at 1208C for
19 h. After being cooled to RT, H2O (210 mL) was added. A clear
orange solution was obtained by filtration and being subsequently
washed with H2O (60 mL). The addition of NaOTf (5.16 g, 30 mmol)
in H2O (15 mL) under stirring resulted in the formation of a fine
precipitate. Larger particles formed when this suspension was
heated at 1008C for 1 h. The precipitate was filtered, washed with
small amounts of H2O and large amounts of Et2O, and dried in
1
vacuum to give 5c as a powder (1.94 g, 93%). H NMR (400 MHz,
[D6]DMSO, 258C): d=10.04 (s, 1H), 9.36 (d, J=1.77 Hz, 1H), 9.34 (d,
J=1.80 Hz, 1H), 9.34 (d, J=1.78 Hz, 1H), 9.30 (d, J=1.86 Hz, 1H),
9.24 (dd, J=8.30, 1.31 Hz, 1H), 8.16 (dd, J=5.29, 1.39 Hz, 1H), 8.12
(d, J=5.83 Hz, 1H), 8.06 (d, J=5.82 Hz, 1H), 8.01 (dd, J=5.27,
ꢂ 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
ChemPlusChem 2014, 79, 936 – 950 947