with a signiÐcant amount of [Ru(ttpy)(tpy-z-OH)]2`. Chro-
exchange with KPF . The product was identiÐed by NMR
6
matography was repeated using a superior grade of silica
and MS as [Ru(ttpy)(tpy-OH)](PF )
2.08 ] 10~5 mol, 17%). 1H NMR (500 MHz, CD CN)
(assigned using 1HÈ1H COSY): d 8.96 (s, 2H, H3{ ttpy), 8.62
(yield 20 mg,
6 2
(ICN Biomedicals, 32È63, 60 A) and CH CN as the principal
3
3
eluant rather than a mixture of acetonitrile and acetone. The
polarity of the eluant was increased as before and the fractions
(d, 2H, J 8.0, H3 ttpy), 8.40 (d, 2H, J 8.4, H3 HO-tpy), 8.22 (s,
2H, H3{, HO-tpy), 8.09 (d, 2H, J 8.0, H2 phenyl), 7.90 (two
overlapping m, 4H, apparent J 8.4, H4 both terpys), 7.57 (d,
2H, J 7.8, H3 phenyl), 7.45 (d, 2H, J 5.0, H6 one terpy), 7.36 (d,
2H, J 5.4 Hz, H6 one terpy), 7.15 (two overlapping m, 4H, H5
subjected to anion exchange with KPF . Although, again, the
6
bulk of the product eluted as a mixture, a small amount of
[Ru(ttpy)(tpy-z-z-NO )]2` was obtained free of the second
2
complex (yield 6 mg, 6%); spectroscopic data was consistent
with that for the product obtained from reaction of
both terpys), 2.53 (s, 3H, tolyl CH ). ES-MS: m/z 672 ([M]`,
3
Ru(ttpy)Cl with the ligand tpy-z-z-NO .32 1H NMR (500
12), 336 ([M]2`, 100%). UV-Vis j /nm (CH CN): 490, 303,
3
2
max
3
MHz, d6-acetone) (assigned using 1HÈ1H NOESY): d 9.41 (s,
284, 273 sh; [in KNO (aq)]: 498, 304, 280. Emission (j
498 nm, 293 K, KNO (aq)]: j \ 651 nm.
\
3
ex
2H, H3{, NO -z-z-tpy), 9.31 (s, 2H, H3{, ttpy), 8.95 (two over-
lapping d, 4H, J 9, H3 both terpys), 8.43 (d, 2H, J 8.5, Hb),
2
3
max
8.32 (d, 2H, J 8.5, Hx), 8.15 (d, 2H, J 8.5, H2 phenyl ttpy), 8.10
(d, 2H, J 8.5, Ha), 8.07 (d, 2H, J 8.5, Hy), 7.99 (two overlapping
m, 4H, apparent J 7.5, H4 both terpys), 7.72 (two overlapping
m, 4H, apparent J 5, H6 both terpys), 7.46 (d, 2H, J 8.5, H3
phenyl ttpy), 7.24 (two overlapping m, apparent J 6.5 Hz, H5
both terpys), 2.42 (s, 3H, CH ). ES-MS: m/z 999 ([MPF ]`,
Cross-coupling reaction of [Ru(ttpy)L7](PF ) with 4º-
6 2
solution
(dimethylamino)benzeneboronic
acid.
A
of
[Ru(ttpy)L7](PF ) (196 mg, 1.94 ] 10~4 mol, 1 equiv.) in
6 2
DMSO (7 mL) was added to Pd(PPh ) (13 mg, 1.15 ] 10~5
3 4
mol, 0.06 equiv.) in the same solvent (1 mL) in a small Schlenk
tube under nitrogen. The mixture was stirred for 10 min while
3
6
3), 426 ([M]2`, 100%). UV-Vis (CH CN) j /nm: 492, 328
max
degassing with N . A suspension of 4-(dimethylamino)benze-
3
2
(sh), 311, 285 (sh).
neboronic acid (63 mg, 3.82 ] 10~4 mol, 2 equiv.) in DMSO
(3 mL) was added to the solution, followed by 2 M Na CO
(aq) (288 lL, 3 equiv.). The mixture was degassed further
2
3
[Ru(ttpy)(L7)](PF ) . This complex was prepared in the
6 2
same way as [Ru(ttpy)L3](PF ) (method A, above) from
before heating at 85 ¡C for 18 h under N . TLC after 18 h
6 2
2
Ru(ttpy)Cl (321 mg, 6.05 ] 10~4 mol, 1 equiv.) but using
3
showed that the starting complex had been completely con-
ligand L7 (189 mg, 6.05 ] 10~4 mol) in place of L3. At the end
sumed. It should be noted that under di†erent reaction condi-
of the reaction in ethanol, a precipitate formed rapidly which
was collected by centrifugation and washed once with ethanol.
tions (DMEÈCH CNÈEtOH as the solvent system and
3
reaction time of 6 h) only partial conversion to product
The 1H NMR of the solid, after anion exchange with KPF ,
occurred. The reaction mixture was diluted with CH CN and
6
3
added dropwise to a saturated KPF (aq) solution. The pre-
6
showed a good level of purity of the desired product. Never-
theless, further puriÐcation was carried out by chromatog-
raphy under the conditions described above followed by anion
exchange of the eluted fractions, leading to the desired
complex as a redÈbrown solid (yield 329 mg, 3.21 ] 10~4 mol,
cipitate which initially formed was washed with water and
found to be the spectroscopically pure product (yield 126 mg,
1.18 ] 10~4 mol, 61%). A further 56 mg of crude product sub-
sequently precipitated, which could be puriÐed chromato-
graphically on silica using CH CNÈacetone, H O and KNO
53%). 1H NMR (500 MHz, CD CN) (assigned using 1HÈ1H
3
3
2
3
COSY and NOESY): d 8.98 (s, 4H, H3{ both terpys), 8.63 (d,
as the eluants. 1H NMR (500 MHz, d6-acetone) (assigned
2H, J 8.0, H3 one terpy only), 8.49 (d, 2H, J 7.8, H3 one terpy
only), 8.10 (d, 2H, J 8.4, H2 phenyl), 7.94 (td, 4H, J 7.9, 1.4, H4
both terpys), 7.57 (d, 2H, J 8.0, H3 phenyl), 7.45 (dd, 2H, J 5.4,
0.8, H6 one terpy only), 7.37 (dd, 2H, J 5.4, 0.8 Hz, H6 one
terpy only), 7.18 (m, 4H, H5 both terpys), 2.53 (s, 3H, tolyl
CH ). 13C and 1HÈ13C HETCOR (500 MHz, CD CN): d
using 1HÈ1H NOESY): d 9.38 (s, 2H, H3{ ttpy or Me N-z-
2
tpy), 9.30 (s, 2H, H3{ ttpy or Me N-z-tpy), 9.00 (dd, 4H, J 7.8,
2
5.3, H3 both terpys) 8.22 (m, 4H, H2 on phenyl both terpys),
8.05 (tdd, 4H, J 9.0, 3.5, 1.3, H4 both terpys), 7.81 (d, 2H, J 5.0,
H6 either ttpy or Me N-z-tpy), 7.74 (d, 2H, J 4.8, H6 either
2
ttpy or Me N-z-tpy), 7.54 (d, 2H, J 8.0, H3 on phenyl ttpy),
3
3
2
158.4 (C), 157.3 (C), 156.5 (C), 155.5 (C), 152.8 (C), 148.9 (CH,
Hs at d 7.45 and 7.37), 141.4 (C), 138.4 (C), 134.1 (CH, H at d
7.94), 130.6 (C), 128.1 (C), 127.9 (C), 127.6 (C), 127.0 (CH, H at
d 7.57), 125.1 (CH, H at d 7.18), 124.8 (CH, H at d 8.10 and
7.18), 123.6” (CH, H at d 8.98), 121.7 (CH, Hs at d 8.63 and
8.49), 20.7 (tolyl CH ). ES-MS: m/z 882 ([MPF ]`, 11), 367
7.30 (m, 4H, H5, both terpys), 7.01 (d, 2H, J 9.0 Hz, H3 on
phenyl Me N-z-tpy), 3.13 [s, 6H, (CH ) N], 2.49 (s, 3H, ttpy
2
3 2
CH ). 13C NMR (500 MHz, d6-acetone): d 159.74, 159.58,
156.81, 156.19, 153.45, 153.19, 149.53, 148.85, 141.69, 138.95,
3
134.67, 131.14, 131.04, 129.42, 128.58, 128.44, 125.42, 125.41,
123.62, 121.98, 120.31, 113.24, 40.23 [(CH ) N], 21.34 (ttpy
3
6
3 2
([M]2`, 100%). UV-Vis j /nm (CH CN): 486, 308, 283,
max
275; [KNO (aq)]: 485, 307, 282, 274. Emission [j \ 485
ex
CH ). ES-MS: m/z 388 ([M]2`, 100%). UV-Vis j /nm
3
3
max
(CH CN): 501, 310, 286 (sh) nm. Emission (j \ 498 nm, 293
3
3
ex
nm, 293 K, KNO (aq)]: j \ 650 nm.
K, CH CN): j \ 659 nm.
max
3
max
3
Reaction of [Ru(ttpy)L7](PF ) with B neo , leading to
6 2
2
2
[Ru(ttpy)(tpy-OH)]2‘. Dry, degassed DMSO (3 mL) was
Acknowledgements
added to
a
mixture of [Ru(ttpy)L7](PF ) (126 mg,
6 2
1.23 ] 10~4 mol), B neo (55 mg, 2.46 ] 10~4 mol, 2 equiv.),
Financial support from the EPSRC is gratefully acknow-
ledged. We should also like to thank Professor Todd Marder
for helpful discussions on boronic acid chemistry and Dr
Andrew Beeby for access to instrumentation for time-resolved
luminescence measurements.
2
2
PdCl (dppf) (10.1 mg, 1.23 ] 10~5 mol, 0.1 equiv.) and KOAc
2
(48 mg, 4.91 ] 10~4 mol, 4 equiv.) in a small Schlenk tube
under nitrogen, and the mixture heated at 80 ¡C. After 3 h,
dppf (7 mg, 1.23 ] 10~5 mol, 0.1 equiv.) was added, and
heating continued for a further 2.5 h. After anion exchange
with KPF , the residue was chromatographed on silica, initial
6
eluant acetonitrileÈacetone (1 : 1), and polarity increased with
References and notes
H O and KNO (aq). The fractions containing a pure product
eluted with 0.4È0.8% KNO
CH CNÈMe CO (1 : 1) and were subjected to further anion
2
3
1
2
N. Miyaura and A. Suzuki, Chem. Rev., 1995, 95, 2457.
The unifying chemistry behind many such coupling procedures is
discussed in: Organometallics in Synthesis, ed. M. Schlosser,
Wiley, Chichester, 1994.
and 12% H O in
3
2
3
2
” From cross-peak in HETCOR only; signal not detectable in the
1-dimensional 13C spectrum.
3
E. C. Constable and M. D. Ward, J. Chem. Soc., Dalton T rans.,
1990, 1405.
1146
New J. Chem., 2001, 25, 1136È1147