6
34
C. Xu
state energy of phenNO was determined to be 20,048
2
1.71 Hz, 1H), 9.31 (dd, J = 4.26, 1.58 Hz, 1H), 9.01 (dd,
J = 8.62, 1.60 Hz, 1H), 8.69 (s, 1H), 8.45 (m, 1H), 7.82
(m, 2H) ppm; IR (KBr): vꢀ = 3,414, 3,080, 1,618, 1,519,
1,419, 1,386, 1,353, 1,202, 1,145, 1,045, 986, 906, 809,
-
cm via the phosphorescence spectra of phenNO and its
1
2
gadolinium complex, which is much higher in energy than
3
the resonance levels of Eu and Sm ions, but lower than
?
3?
3
?
3?
-1
?
those of Tb
and Dy
ions. So it can be predicted
3
734, 623 cm ; EIMS (70 eV): m/z (%) = 225 (64, M ),
179 (100), 167 (37), 152 (24), 125 (17), 99 (10), 75 (13).
?
that phenNO is able to sensitize the luminescence of Eu
2
3
?
and Sm . The values of the emission intensities and the
relative luminescence quantum yields for these two lumi-
nescent complexes, determined to be 20,190, 14.8% and
Preparation of the complexes
1
3,920, 10.2%, respectively, indicate that the europium
Lanthanide oxides (Eu O , Gd O , Sm O , and Dy O )
2 3 2 3 2 3 2 3
complex shows stronger luminescence compared with the
samarium complex, which suggests that the triplet state
were converted to their chlorides by treatment with con-
centrated hydrochloric acid and evaporated just to dryness.
For the preparation of the terbium chloride, whose oxides
energy of phenNO is more suitable for the sensitization of
2
3?
3
?
Eu than for Sm
.
contain the lanthanide in a higher oxidation state (Tb O ),
4 7
hydrogen peroxide was used as the reductant. The corre-
sponding lanthanide complexes with the ligand phenNO2
were prepared by the same method described below.
To a stirred solution of lanthanide chloride (2 mmol) in
Experimental
3
The purity of lanthanide oxides used (Eu O , Tb O , Gd O ,
2
15 cm of deionized water was added a solution of 1.35 g
3
(6.0 mmol) in 100 cm of 95% C
3
4
7
2 3
Sm O , and Dy O ) exceeded 99.99%. Other chemicals
2
phenNO
2
2
H
5
OH. The
3
2 3
were analytical grade and used as received. Elemental
analyses (C, H, N) were performed with a Flash-EA1112
elemental analyzer, and lanthanide ions were analyzed by
complexometric titration with EDTA; the results were found
reaction mixture was stirred at 80 ꢁC for 10 h and then
concentrated under reduced pressure to about 25 cm .
3
After cooling to room temperature the precipitate was fil-
3
tered off, washed with water (2 9 10 cm ) and ethanol
3
(2 9 10 cm ), dried, and stored over silica gel.
1
to be in good agreement with the calculated values. H NMR
spectra were collected on a Bruker-400 spectrometer. Mass
spectra were measured on an Aligent 5975 spectroscopy.
Infrared spectra of KBr pellets were measured at room
Trichlorotri(5-nitro-1,10-phenanthroline)europium(III)
dihydrate (C H Cl N O Eu)
3
6
25
3 9 8
Yield: 1.35 g (70%); IR (KBr): vꢀ = 3,412, 3,079, 1,621,
-
1
temperature in the 400–4,000 cm region by using a Bruker
Tensor 27 FT-IR spectrophotometer. UV spectra of
1
8
,520, 1,420, 1,383, 1,352, 1,200, 1,145, 1,044, 986, 905,
1
-
09, 732, 622 cm
.
-
.0 9 10 mol dm solutions in ethanol were obtained by
5
-3
2
a Perkin-Elmer Lambda 25 spectrophotometer. Lumines-
4
cence and phosphorescence spectra of 5.0 9 10
Trichlorotri(5-nitro-1,10-phenanthroline)terbium(III)
dihydrate (C36 Tb)
-
H25Cl N O
3 9 8
-
3
mol dm solutions in ethanol were recorded in an Hitachi
F-4500 spectrophotometer equipped for both room temper-
ature and 77-K measurements. The luminescence quantum
yields were measured by using quinine sulfate in 1.0 M
H SO (U = 54.6%) as reference [29].
Yield: 1.32 g (68%); IR (KBr): vꢀ = 3,418, 3,082, 1,621,
1,521, 1,420, 1,384, 1,353, 1,201, 1,145, 1,044, 987, 906,
-
1
807, 732, 621 cm
.
Trichlorotri(5-nitro-1,10-phenanthroline)samarium(III)
dihydrate (C H Cl N O Sm)
2
4
3
6
25
3 9 8
5-Nitro-1,10-phenanthroline
The directions given by Hammett et al. [13] were used with
Yield: 1.44 g (75%); IR (KBr): vꢀ = 3,421, 3,085, 1,621,
1,518, 1,419, 1,385, 1,354, 1,202, 1,144, 1,044, 986, 907,
-
807, 733, 621 cm .
1
the following modifications. To a stirred solution of 10.0 g
3
,10-phenanthroline (55.6 mmol) in 15 cm of 95% sulfu-
1
Trichlorotri(5-nitro-1,10-phenanthroline)dysprosium(III)
dihydrate (C H Cl N O Dy)
ric acid was added a mixture of concentrated nitric acid/
3
5% sulfuric acid (1:1, 60 cm ) at such a rate that the
36 25
3 9 8
9
Yield: 1.32 g (72%); IR (KBr): vꢀ = 3,420, 3,083, 1,621,
temperature approached but did not exceed 170 ꢁC.
Heating was then continued for 3 h at reflux. The mixture
was then cooled, poured on ice, and neutralized with 30%
sodium hydroxide solution. The precipitate was filtered,
washed with cold water, and dried. Crystallization from
ethanol yielded 9.8 g (86%) of a light yellow crystalline
1
8
,519, 1,419, 1,386, 1,355, 1,200, 1,143, 1,045, 987, 906,
-
1
07, 731, 622 cm
.
Trichlorotri(5-nitro-1,10-phenanthroline)gadolinium(III)
dihydrate (C36 Gd)
H
25Cl N O
3 9 8
Yield: 1.45 g (75%); IR (KBr): vꢀ = 3,419, 3,081, 1,620,
1,520, 1,419, 1,386, 1,354, 1,201, 1,144, 1,045, 986, 908,
-
806, 732, 622 cm .
1
solid, m.p. 201.8–202.3 ꢁC (Ref. [13] m.p. 202 ꢁC). H
NMR (400 MHz, CDCl3): d = 9.37 (dd, J = 4.34,
1
1
23