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solid. Subsequent recrystallization from CH Cl /Et O afforded com-
7.97 (d, 2H, J=5.7 Hz; H3 of Ph -phen), 7.80–7.60 (m, 23H; H8 and
2
2
2
2
1
plex 1 as red crystals. Yield: 60.5 mg (68%); H NMR (300 MHz,
CD COCD , 298 K): d=9.49 (s, 1H; H3 of bpy-nitrone-Me), 8.84 (d,
phenyl ring of Ph -phen and H6’ of bpy-nitrone-Me), 7.38 (d, 1H,
2
J=5.7 Hz; H5’ of bpy-nitrone-Me), 4.00 (s, 3H; CH3 of nitrone
3
3
4
H, J=8.1 Hz; H3 and H3’ of bpy), 8.61 (s, 1H; H3’ of bpy-nitrone-
moiety of bpy-nitrone-Me), 2.63 ppm (s, 3H; CH of pyridyl ring of
3
ꢁ
1
Me), 8.28–8.04 (m, 11H; H4, H4’, H6, and H6’ of bpy and H5, H6,
and CH=N of nitrone moiety of bpy-nitrone-Me), 7.89 (d, 1H, J=
5
bpy-nitrone-Me); IR (KBr): n=1617 (C=N), 1178 (NꢁO), 838 cm
ꢁ
ꢁ
+
(PF ); MS (ESI, positive-ion mode): m/z: 1140.1 [MꢁPF ] , 497.2
6
6
ꢁ
2+
.7 Hz; H6’ of bpy-nitrone-Me), 7.60 (t, 4H, J=6.6 Hz; H5 and H5’
[Mꢁ2ꢁPF
]
;
elemental
analysis
calcd
(%)
for
6
of bpy), 7.45 (d, 1H, J=5.7 Hz; H5’ of bpy-nitrone-Me), 4.00 (s, 3H;
RuC H N OP F ·3H O: C 54.79, H 3.84, N 7.33; found: C 54.82, H
61 45 7 2 12 2
CH of nitrone moiety of bpy-nitrone-Me), 2.62 ppm (s, 3H; CH of
3.86, N 7.30.
3
3
pyridyl ring of bpy-nitrone-Me); IR (KBr): n=1618 (C=N), 1190 (Nꢁ
N-Phenylhydroxylamine:
A
mixture of nitrobenzene (1 g,
ꢁ
1
ꢁ
O), 841 cm
(PF ); MS (ESI, positive-ion mode): m/z: 786.6
6
8.13 mmol), NH Cl (500 mg, 9.35 mmol), and zinc dust (1.18 g,
4
ꢁ
+
ꢁ 2+
[
MꢁPF ] , 320.7 [Mꢁ2ꢁPF ] ; elemental analysis calcd (%) for
6
6
17.89 mmol) was stirred in H O (15 mL) at room temperature for
4 h. The solution was filtered and extracted with CH Cl (50 mLꢁ3).
The combined organic phase was dried over MgSO and evaporat-
2
RuC H N OP F ·H O: C 41.78, H 3.29, N 10.34; found: C 41.94, H
3
3
29
7
2
12
2
2
2
3
.21, N 10.25.
4
ed to dryness under vacuum, leaving a yellow solid. Subsequent
[
Ru(bpyC4) (bpy-nitrone-Me)](PF ) (2): The synthetic procedure
2
6 2
recrystallization from CH Cl /Et O afforded the product as a pale
was similar to that for complex 1, except that cis-[Ru(b-
pyC4) Cl ]·2H O (70.0 mg, 0.08 mmol) was used instead of cis-
2
2
2
1
yellow solid. Yield: 530 mg (60%); H NMR (300 MHz, CDCl3,
98 K): d=7.32 (t, 2H, J=8.4 Hz; H3 and H5), 7.08–6.98 (m, 3H;
H2, H4, and H6), 6.90–6.70 (m, 2H; OH and NH); MS (ESI, positive-
2
2
2
2
[
Ru(bpy) Cl ]·2H O. Subsequent recrystallization from CH Cl /Et O
2 2 2 2 2 2
1
afforded complex 2 as red crystals. Yield: 63.7 mg (63%); H NMR
300 MHz, CD COCD , 298 K): d=9.48 (s, 1H; H3 of bpy-nitrone-
+
+
ion mode): m/z: 110.4 [M+H ] .
(
3
3
Me), 9.17 (s, 4H; H3 and H3’ of bpyC4), 8.63 (s, 1H; H3’ of bpy-ni-
trone-Me), 8.36–8.21 (m, 8H; H6, H6’, and CONH of bpyC4), 8.18–
[Ru(bpy) (bpy-nitrone-Ph)](PF ) (5): A solution of [Ru(bpy) (bpy-
2
6
2
2
CHO)](PF ) (20 mg, 0.02 mmol) and N-phenylhydroxylamine (4 mg,
6
2
8
.03 (m, 3H; H5, H6, and CH=N of nitrone moiety of bpy-nitrone-
0.04 mol) in CH Cl (5 mL) was stirred at room temperature for 72 h
2 2
Me), 7.96–7.86 (m, 5H; H5 and H5’ of bpyC4 and H6 of bpy-ni-
trone-Me), 7.44 (d, 1H, J=5.1 Hz; H5’ of bpy-nitrone-Me), 4.00 (s,
to precipitate a red solid. The red solid was collected and washed
with CH Cl and Et O. Subsequent recrystallization from acetone/
2
2
2
3
6
H; CH3 of nitrone moiety of bpy-nitrone-Me), 3.44 (t, 8H, J=
.0 Hz; CH CH CH CH of bpyC4), 2.62 (s, 3H; CH of pyridyl ring of
Et O afforded complex 5 as red crystals. Yield: 17 mg (77%);
2
1
3
2
2
2
3
H NMR (300 MHz, CD COCD , 298 K): d=9.73 (s, 1H; H3 of bpy-ni-
3
3
bpy-nitrone-Me), 1.68–1.52 (m, 8H; CH CH CH CH of bpyC4), 1.48–
trone-Ph), 8.86 (d, 4H, J=8.1 Hz; H3 and H3’ of bpy), 8.78 (s, 1H;
CH=N of nitrone moiety of bpy-nitrone-Ph), 8.67 (s, 1H; H3’ of
bpy-nitrone-Ph), 8.38 (d, 1H, J=6.3 Hz; H5 of bpy-nitrone-Ph),
8.30–7.90 (m, 12H; H4, H4’, H6, and H6’ of bpy and H6, H6’, and
phenyl ring of bpy-nitrone-Ph), 7.70–7.60 (m, 7H; H5 and H5’ of
bpy and phenyl ring of bpy-nitrone-Ph), 7.48 (d, 1H, J=5.7 Hz; H5’
of bpy-nitrone-Ph), 2.65 ppm (s, 3H; CH3 of bpy-nitrone-Ph); IR
3
2
2
2
1
.32 (m, 8H; CH CH CH CH of bpyC4), 0.95ppm (t, 12H, J=7.4 Hz;
3 2 2 2
CH CH CH CH of bpyC4); IR (KBr): n=1656 (C=O), 1622 (C=N),
3
2
2
2
ꢁ
1
ꢁ
1
544 (NꢁH), 1178 (NꢁO), 844 cm (PF ); MS (ESI, positive-ion
6
ꢁ
+
ꢁ 2+
6
mode): m/z: 1183.0 [MꢁPF ] , 519.1 [Mꢁ2ꢁPF ] ; elemental
6
analysis calcd (%) for RuC H N O P F ·2H O: C 46.70, H 5.10, N
53
65 11
5
2
12
2
11.30; found: C 46.72, H 4.86, N 11.23.
ꢁ
1
ꢁ
(
KBr): n=1618 (C=N), 1088 (NꢁO), 841 cm (PF ); MS (ESI, posi-
[
Ru(phen) (bpy-nitrone-Me)](PF ) (3): The synthetic procedure
6
2
6 2
ꢁ
+
ꢁ 2+
6
tive-ion mode): m/z: 847.8 [MꢁPF ] , 351.7 [Mꢁ2ꢁPF ] ; ele-
was similar to that for complex 1, except that cis-[Ru-
6
mental analysis calcd (%) for RuC H N OP F ·3H O: C 43.60, H
(
[
phen) Cl ]·2H O (45.0 mg, 0.08 mmol) was used instead of cis-
38 31
7
2
12
2
2
2
2
3
.56, N 9.37; found: C 43.53, H 3.77, N 9.40.
Ru(bpy) Cl ]·2H O. Subsequent recrystallization from CH Cl /Et O
2
2
2
2
2
2
1
afforded complex 3 as red crystals. Yield: 62.0 mg (80%); H NMR
300 MHz, CD COCD , 298 K): d=9.52 (s, 1H; H3 of bpy-nitrone-
(
Instrumentation and methods
The instruments for the characterization and photophysical meas-
3
3
Me), 8.87 (d, 2H, J=8.4 Hz; H4 of phen), 8.76 (d, 2H, J=8.4 Hz; H7
of phen), 8.66–8.55 (m, 3H; H2 of phen and H3’ of bpy-nitrone-
Me), 8.47–8.37 (m, 4H; H5 and H6 of phen), 8.28 (d, 2H, J=5.4 Hz;
H9 of phen), 8.09 (s, 1H; CH=N of nitrone moiety of bpy-nitrone-
Me), 8.06–7.96 (m, 4H; H3 of phen and H6 and H6’ of bpy-nitrone-
Me), 7.86 (d, 1H, J=6.0 Hz; H5 of bpy-nitrone-Me), 7.79–7.72 (m,
[
10]
urements have been described previously.
Emission quantum
[32]
yields were measured by using the optically dilute method with
an aerated aqueous solution of [Ru(bpy) ]Cl (F =0.028) as the
3
2
em
[33]
standard solution.
2
3
3
H; H8 of phen), 7.32 (d, 1H, J=4.8 Hz; H5’ of bpy-nitrone-Me),
.98 (s, 3H; CH of nitrone moiety of bpy-nitrone-Me), 2.60 ppm (s,
Kinetics studies
3
H; CH of pyridyl ring of bpy-nitrone-Me); IR (KBr): n=1618 (C=
3
The rate measurements of the SPANC reactions between the com-
plexes (10 mm) and BCN-OH (0.5, 1, 1.5, and 2 mm) in MeOH at
ꢁ1
ꢁ
N), 1178 (NꢁO), 840 cm (PF ); MS (ESI, positive-ion mode): m/z:
6
ꢁ
+
ꢁ 2+
6
8
36.6 [MꢁPF ] , 344.4 [Mꢁ2ꢁPF ] ; elemental analysis calcd
6
2
98 K were conducted by UV/Vis absorption spectroscopy. The re-
(
%) for RuC H N OP F ·2H O: C 43.80, H 3.28, N 9.66; found: C
37 29 7 2 12 2
actions were monitored by following the decrease in the absorb-
ance at 329 nm of the complexes upon addition of BCN-OH. Data
were fitted to a single-exponential equation to give the pseudo-
first-order rate constants kobs, which were then plotted against the
concentrations of BCN-OH to obtain the second-order rate
constant k2.
4
3.77, H 3.15, N 9.61.
[Ru(Ph -phen) (bpy-nitrone-Me)](PF ) (4): The synthetic proce-
2 2 6 2
dure was similar to that for complex 1, except that cis-[Ru(Ph2-
phen) Cl ]·2H O (40.0 mg, 0.05 mmol) was used instead of cis-
2
2
2
[
Ru(bpy) Cl ]·2H O. Subsequent recrystallization from CH Cl /Et O
2 2 2 2 2 2
1
afforded complex 4 as red crystals. Yield: 35.0 mg (60%); H NMR
300 MHz, CD COCD , 298 K): d=9.55 (s, 1H; H3 of bpy-nitrone-
(
3
3
Photophysical changes toward RONS and biothiols
Me), 8.79–8.68 (m, 3H; H2 of Ph -phen and H3’ of bpy-nitrone-Me),
2
8
.57–8.50 (m, 2H; H9 of Ph -phen), 8.40–8.30 (m, 4H; H5 and H6 of
The possible changes in the emission intensity of the complexes
(10 mm) were investigated upon incubation with various RONS
(100 mm) and biothiols (1 mm) in aerated potassium phosphate
2
Ph -phen), 8.17–8.09 (m, 2H; H6 and CH=N of nitrone moiety of
bpy-nitrone-Me), 8.02 (d, 1H, J=5.7 Hz; H5 of bpy-nitrone-Me),
2
Chem. Eur. J. 2016, 22, 1 – 12
9
ꢀ 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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&
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