H. Lu et al. / Journal of Photochemistry and Photobiology A: Chemistry 215 (2010) 46–51
47
lane [H2N(CH2)2HN(CH2)3SiCH3(OCH3)2, AEP for short] as
a
The preparation of functionalized polysiloxane was as fol-
lows: benzoylamido side functionalized silane (1.59 g, 5 mmol)
(or acetamido side functionalized silane (1.28 g, 5 mmol)),
octamethylcycoltetrasiloxane (7.61 g, 25 mmol), hexamethyldis-
iloxane (0.32 g, 2 mmol) and a stoichiometric proportion tetram-
ethylammonium silanolate (used as catalyzer) were added to
a flask under N2. The mixture was heated to 85–95 ◦C for 8 h
under uniform mechanical stirring. After the catalyzer is decom-
posed at 130–140 ◦C and the low-boilings are removed in vacuum
(10 mm Hg), yellow viscous liquid was obtained.
Benzoylamido side functionalized polysiloxane (BA-PS for
short) (yield 83%): 1H-NMR (CDCl3): ␦7.48 (d, 2H, –phenyl-H–),
7.39 (d, 1H, –phenyl-H–), 7.32 (d, 2H, –phenyl-H–), 8.04 (s, 1H, -
phenyl–CONH–), 3.27 (t, 2H, –CH2–), 3.01 (t, 2H, –CH2–), 2.00 (s,
IH, –N–H–), 1.61 (s, 2H, –CH2–), 0.62 (m, 2H, –CH2–), 0.34 (t, 2H,
–CH2–), 0.05(s, 108H, –Si–CH3).
starting material in this paper. It was modified via acylamidation
with benzoyl chloride (PhCOCl) or acetyl chloride (CH3COCl) to
get two new silane intermediates. Innovation of selecting different
chlorides modification builds upon the introduction of disparate
conjugated systems. Then the intermediates were copolymer-
ized with octamethylcycoltetrasiloxane and hexamethyldisiloxane
to give two different acylamido side functionalized polysilox-
anes, namely benzoylamido side functionalized polysiloxane and
acetamido side functionalized polysiloxane. These functionalized
polysiloxanes are chelated to lanthanide ions (Tb3+, Eu3+, Dy3+ and
Sm3+, separately) at room temperature to obtain the anticipant
luminescent polysiloxane–lanthanide ion composite materials. The
photophysical performances of the materials were discussed and
the intra-molecular energy transfer processes were compared in
detail.
Acetamido side functionalized polysiloxane (AA-PS for short)
(yield 85%): 1H-NMR (CDCl3): ␦6.75 (s, 1H, –CH3–CONH–), 3.01 (t,
2H, –CH2–), 2.91 (t, 2H, –CH2–), 2.78 (t, 2H, –CH2–), 2.44 (s, 3H,
–CH3), 2.01 (s, 1H, –N–H–), 1.62 (m, 2H, –CH2–), 0.52 (t, 2H, –CH2–),
0.05(s, 114H, –Si–CH3).
2. Experimental
2.1. Chemicals and procedures
The luminescent polysiloxane–lanthanide ion composite mate-
rial was achieved as follows: 0.945 g benzoylamido side func-
tionalized polysiloxane (or 0.938 g acetamido side function-
alized polysiloxane) was dissolved in 6 mL CH3Cl with stir-
ring, and 6 mmol Ln(NO3)3·6H2O (0.2736 g Tb(NO3)3·6H2O,
0.2676 g Eu(NO3)3·6H2O, 0.2739 g Dy(NO3)3·6H2O or 0.2666 g
China National Medicines Group and were distilled before utiliza-
tionaccordingto procedures in previousarticles [26–28]. Rare earth
nitrates (Ln(NO3)3·6H2O, Ln = Tb, Eu, Dy or Sm) were obtained from
the corresponding oxides in dilute nitric acid [26,28].
The general procedures for the preparation of acylamido
side functionalized polysiloxanes and luminescent materials are
expounded in the Scheme1. Theacylationreaction was described as
follows: N--aminoethyl-␥-aminopropylmethyldimethoxysilane
(2.47 g, 12 mmol) was first dissolved in 20 mL pyridine by stirring
and then benzoyl chloride (1.68 g, 12 mmol) (or 0.942 g, 12 mmol
acetyl chloride) was added to the solution dropwise at room
temperature. The mixture was refluxing at 70 ◦C for 4 h. After
the filtration, the resulting solution was condensed to evaporate
the solvent and then the residue was dried on a vacuum line
(10 mm Hg). Yellow liquid was obtained with yield of about 91%.
Benzoylamido side functionalized silane (BA-AEP for short):
a
single phase. Then 20 mL methanol was poured into the
mixture. The viscous liquids were collected by filtration and
washed with methanol, water and acetone. After dried under
vacuum at room temperature [26],
a yellow viscous liquid
product (yield among 92–94%) was obtained. The luminescent
polysiloxane–lanthanide ion composite materials were named
BA-PS-Ln (Ln = Tb, Eu, Dy or Sm) and AA-PS-Ln (Ln = Tb, Eu, Dy
or Sm).
2.2. Measurements
C
15H26N2O3Si: 1H-NMR (CDCl3): ␦7.49 (d, 2H, –phenyl-H–), 7.41
(d, 1H, –phenyl-H–), 7.38 (d, 2H, –phenyl-H–), 7.86 (s, 1H, –phenyl-
CONH–), 3.76 (s, 6H, –OCH3), 3.28 (t, 2H, –CH2–), 3.17 (t, 2H, –CH2–),
2.94 (t, 2H, –CH2–), 1.95 (s, IH, –N–H–), 1.63 (m, 2H, –CH2–), 0.64
(t, 2H, –CH2–), 0.15 (t, 3H, –Si–CH3).
Acetamido side functionalized silane (AA-AEP for short):
C15H26N2O3Si: 1H-NMR (CDCl3): ␦6.75 (s, 1H, –CH3–CONH–), 3.51
(s, 6H, –OCH3), 3.02 (t, 2H, –CH2–), 2.90 (t, 2H, –CH2–), 2.77 (t, 2H,
–CH2–), 2.09 (s, 3H, –CH3), 1.86 (s, 1H, –N–H–), 1.61 (m, 2H, –CH2–),
0.63 (t, 2H, –CH2–), 0.15 (t, 3H, –Si–CH3).
Bruker TENSOR27 infrared spectrophotometer was utilized to
record the Fourier transform infrared (FT-IR) spectra with the
KBr pellet technique within the 4000–400 cm−1 region. BRUKER
AVANCE-400 spectrometer was used to determine the Proton
Nuclear Magnetic Resonance (1H-NMR) spectra in CDCl3 without
internal reference. Diffuse reflectance ultraviolet–visible spectra
(DRUVS) of samples were performed with a Shimadzu UV-2500.
Thermal gravimetric analysis (TGA) was performed with a simulta-
neous TGA Q600 under N2. Luminescence (excitation and emission)
Scheme 1. The procedures for the preparation of acylamido side functionalized polysiloxane. (i) RCOCl (R = –CH3, –C6H5), pyridine, 70 ◦C. (ii) Hexamethyldisiloxane,
octamethylcycoltetrasiloxane.