PAPER
Synthesis of Europium(III) Terpyridyl Chelates
2403
refluxed for 1 h, concentrated by rotary evaporation to a volume of
about 10 mL and filtered through a short silica column (CH2Cl2–
EtOAc, 10:1). The solvent was removed under reduce pressure, the
residue was stirred in EtOAc (10 mL) and filtered to give 3 (795 mg,
55%); mp 242–243 °C.
(EtOAc–hexane, 1:1) yielded 6 (325 mg, 70%); Rf 0.45; mp 124–
126 °C.
IR (KBr): 2949, 1744, 1436, 1200, 1002, 816 cm–1.
1H NMR (DMSO-d6): = 3.57 (s, 12 H), 3.67 (s, 8 H), 4.01 (s, 4 H),
7.41–7.47 (m, 4 H), 7.51–7.58 (m, 4 H), 7.69 (d, 2 H, J = 8.0 Hz),
7.93 (t, 1 H, J = 8.0 Hz), 8.48 (d, 2 H, J = 8.0 Hz), 8.55 (d, 2 H, J =
8.0 Hz).
13C NMR: 51.4 (+), 54.4 (–), 57.6 (–), 119.7 (+), 121.2 (+), 122.1
(Cquat), 131.2 (+), 131.5 (+), 137.4 (Cquat), 137.8 (+), 138.1 (Cquat),
138.8 (Cquat), 154.2 (Cquat), 154.9 (Cquat), 171.7 (Cquat).
IR (KBr): 3084, 2239, 1585, 1479, 1376, 1180, 1074, 1005, 829
cm–1.
1H NMR (CDCl3): = 7.78–7.85 (m, 4 H), 8.04–8.12 (m, 4 H), 8.32
(t, 1 H, J = 8.0 Hz), 8.92 (d, 2 H, J = 8.0 Hz).
13C NMR: = 114.2 (Cquat), 127.0 (+), 127.7 (Cquat), 129.7 (Cquat),
130.6 (+), 132.6 (Cquat), 132.9 (+), 139.4 (+), 152.1 (Cquat), 156.7
(Cquat), 160.6 (Cquat).
MS (ESI): m/z = 888, 890, 892 [MH]+, 910, 912, 914 [MNa]+.
Anal. Calcd for C41H39Br2N5O8 (889.60): C, 55.36; H, 4.42; N, 7.87.
Found: C, 55.45; H, 4.62; N, 7.78.
MS (EI, 70 eV): m/z (%) = 599 (51) [M]+, 597 (100), [M]+, 595 (49)
[M]+.
Anal. Calcd for C25H11Br2N9 (597.23): C, 50.28; H, 1.86; N, 21.11.
Found: C, 50.17; H, 2.09; N, 20.95.
6,6 -bis[N,N-bis(carboxymethyl)aminomethyl]-5,5 -bis(4-bro-
mophenyl)-2,2 :6 ,2 -terpyridine tetralithium salt (7)
Compound 6 (200 mg, 0.22 mmol) was dissolved in a mixture of
THF (4 mL) and MeOH (1 mL). An aq solution of LiOH (1 M, 2
mL, 2 mmol) was added and the solution was heated under reflux
for 30 min. The reaction mixture was cooled to r.t., the precipitate
was separated by filtration and washed with THF to give 7 (170 mg,
0.20 mmol, 90%); mp > 300 °C.
5,5 -Bis(4-bromophenyl)-6,6 -dicyano-2,2 ,6 2 -terpyridine (4)
Dicyanotriazine 3 (1.65 g, 2.76 mmol) and bicyclo[2.2.1]hepta-2,5-
diene (2.54 g, 3 mL, 27.6 mmol) in toluene (10 mL) was heated un-
der reflux for 24 h. Upon cooling a precipitate of 4 formed, which
was collected by filtration, washed with EtOH and dried to give 4
(1.47 g, 90%).
1H NMR (CDCl3): = 7.49–7.56 (m, 4 H), 7.67–7.74 (m, 4 H), 8.00
(d, 2 H, J = 8.5 Hz), 8.06 (t, 1 H, J = 8.0 Hz), 8.61 (d, 2 H, J = 8.0
Hz), 8.85 (d, 2 H, J = 8.5 Hz).
13C NMR (CDCl3): = 116.9 (Cquat), 128.2 (+), 129.0 (+), 130.3 (+),
131.3 (Cquat), 132.4 (+), 134.0 (Cquat), 137.9 (Cquat), 138.3 (+), 138.6
(+), 140.7 (Cquat), 153.3 (Cquat), 156.0 (Cquat).
IR (KBr): 3080, 2230, 1584, 1433, 1072, 813 cm–1.
MS (CI, NH3): m/z (%) = 595 (50), 593 (100), 591 (47) [M]+.
IR (KBr): 2924, 1592, 1435, 1414, 999, 816 cm–1.
1H NMR (MeOD): = 3.17 (s, 8 H), 3.95 (s, 4 H), 7.31–7.39 (m, 4
H), 7.63–7.70 (m, 4 H), 7.91 (d, 2 H, J = 8.0 Hz), 8.21 (t, 1 H, J =
8.0 Hz), 8.36 (d, 2 H, J = 8.0 Hz), 8.45 (d, 2 H, J = 8.0 Hz).
13C NMR: = 57.4 (–), 59.4 (–), 120.4 (+), 122.0 (Cquat), 122.7 (+),
130.6 (+), 131.4 (+), 136.3 (Cquat), 136.7 (Cquat), 138.9 (+), 139.5
(+), 154.3 (Cquat), 155.5 (Cquat), 155.7 (Cquat), 178.7 (Cquat).
MS (ESI): m/z = 832, 838, 844, 850 (for isotopes 79Br, 7Li).
{6,6 -[N,N-bis(carboxymethyl)aminomethyl]-5,5 -bis(4-bro-
mophenyl)-2,2 :6 ,2 -terpyridine}europium(III) Monolithium
Salt (8)
Anal. Calcd for C29H15Br2N5 (593.28): C, 58.71; H, 2.55; N, 11.80.
Found: C, 58.73; H, 2.57; N, 11.55.
A solution of ligand 7 (86 mg, 0.1 mmol) in MeOH (2mL) was add-
ed to a solution of europium(III) chloride hexahydrate (40 mg, 0.11
mmol) in MeOH. The reaction mixture was stirred at r.t. for 6 h.
Complex 8 crystallizes from the reaction mixture, was separated by
filtration and washed with MeOH to give 8 (74 mg, 75%).
6,6 -Bis(aminomethyl)-5,5 -bis(4-bromophenyl)-2,2 :6 ,2 -ter-
pyridine·5HCl (5)
Dinitrile 4 (617 mg, 1.04 mmol) was dissolved in anhyd THF
(10mL) and degassed, then a BH3·THF solution was added (1 M,
10.4 mL, 10.4 mmol) and the reaction mixture was stirred at r.t. for
24 h. The excess of borane was destroyed with MeOH (5 mL). The
solvent was removed by rotary evaporation, the residue was dis-
solved in HCl-saturated EtOH (10 mL) and refluxed for 2 h yield-
ing, after cooling, a precipitate, which after filtration gave 5 (462
mg, 57%); mp > 300 °C.
IR (KBr): 2921, 1603, 1440, 1400, 1004, 816 cm–1.
MS (FAB): m/z = 985, 987, 989, 991 [C37H2779Br2151EuLiN5O8]
978, 980, 982, 984. [C37H2779Br2151EuN5O8], (for all isotopes of Br
and Eu).
HRMS: m/z calcd for C37H2879Br2151EuN5O8H+, 979.9579; found,
979.9559.
IR (KBr): 3032, 2885, 1610, 1453, 1277, 1074, 1000, 822 cm–1.
1H NMR (DMSO-d6): = 4.27 (br q, 4 H, J = 5.6 Hz), 7.48–7.57
(m, 4 H), 7.75–7.82 (m, 4 H), 8.03 (d, 2 H, J = 8.0 Hz), 8.24 (t, 1 H,
J = 7.8 Hz), 8.59 (br t, 6 H, J = 5.2 Hz), 8.74 (d, 2 H, J = 8.2 Hz),
8.95 (d, 2 H, J = 7.7 Hz).
13C NMR: = 40.7 (–), 119.8 (+), 122.0 (Cquat), 122.2 (+), 131.1 (+),
131.7 (+), 134.7 (Cquat), 136.0 (Cquat), 138.3 (+), 139.1 (+), 149.6
(Cquat), 153.4 (Cquat), 153.9 (Cquat).
2,6-Bis[6-cyano-5-(4-bromophenyl)-3,4-cyclopentenopyridyl-
2]pyridine (9)
1-(4-Morpholino)cyclopentene (1.05 mL, 1.00 g, 6.56 mmol) was
added to a solution of dicyanotriazine 3 (980 mg, 1.64 mmol) in tol-
uene and the reaction mixture was heated to reflux for 12 h. The re-
sulting precipitate was separated by filtration, then heated to reflux
in HOAc for 30 min. Crystals of the product were separated by fil-
tration and recrystallized from DMSO to give 9 (730 mg, 66%); Mp
325 °C (dec.).
MS (ESI): m/z = 600, 602, 604 [MH]+.
6,6 -[N,N]bis(methoxycarbonylmethyl)aminomethyl]-5,5 -
bis(4-bromophenyl)-2,2 :6 ,2 -terpyridine (6)
IR (KBr): 2943, 2870, 2228, 1565, 1489, 1403, 1093, 1006, 828
cm–1.
1H NMR (CDCl3): = 2.12 (q, 4 H, J = 7.5 Hz), 2.92 (t, 4 H, J = 7.5
Hz), 3.46 (t, 4 H, J = 7.5 Hz), 7.33–7.41 (m, 4 H), 7.65–7.72 (m, 4
H), 8.05 (t, 1 H, J = 8.0 Hz), 8.31 (d, 2 H, J = 8.0 Hz).
13C NMR: = 25.2 (–), 32.5 (–), 34.0 (–), 117.1 (Cquat), 122.8 (Cquat),
123.7 (Cquat), 124.0 (+), 129.9 (Cquat), 130.6 (+), 132.2 (+), 133.3
A mixture of the bis-amine 5 (405 mg, 0.52 mmol), sodium carbon-
ate (772 mg, 7.28 mmol) and methyl bromoacetate (318 mg, 2.08
mmol) in anhyd CH3CN was heated under reflux for 24 h. The mix-
ture was concentrated in vacuum, mixed with water and extracted
with CH2Cl2 (3 × 10 mL). The organic extract was dried over sodi-
um sulfate and evaporated. Purification by column chromatography
Synthesis 2003, No. 15, 2400–2404 © Thieme Stuttgart · New York