130
H.G. Alt, M. Jung / Journal of Organometallic Chemistry 568 (1998) 127–131
3.2. Chemicals
second heating phase (20 K min−1) from 50 to 200°C,
second cooling phase (−20 K min−1) −50°C. The
temperature was linearly corrected relative to indium
(m.p. 156.6°C); the fusion enthalpy of indium (DHm=
28.45 J g−1) was used for calibration. To determine the
crystallinity degree h, the relationship h=DHm/DHm0
was used. DHm derives from the data of the second
heating course of the DSC. DH0m as fusion enthalpy for
100% crystalline polyethylene was assumed to be 290 J
g−1 [10].
Fluorene and indene (Fluka) were purified by filtra-
tion of their pentane solutions over silica.
Methylaluminoxane (Witco, Bergkamen) was used as
a 30 wt.% solution in toluene (average molecular weight
1100 g mol−1; total aluminum content 13.1 wt.% Al
with 3.5 wt.% as trimethylaluminum).
All other commercially available chemicals were em-
ployed without further purification.
3.3. NMR spectroscopy
3.6.2. Viscosimetry
The intrinsic viscosity Mp was determined using an
(
The NMR spectrometers Jeol JNM-EX 270 E,
Bruker ARX 250 and Bruker DRX 500 were available
to record the NMR spectra. The samples were filled
under argon and routinely measured in CDCl3 at 25°C.
The chemical shifts in 1H-NMR spectra refer to the
residual proton signal of the solvent (l=7.24 for
CHCl3), the shifts in the 13C-NMR spectra to the
solvent signal (l=77.0 for CDCl3) and in 31P-NMR
spectra to the resonance of external aqueous phosphoric
acid (l=0.0).
Ubbelohde precision capillary viscometer in cis/trans
decalin at 13590.1°C. Prior to the measurements, the
samples were weighed into sealable small flasks and
dissolved in an exactly measured amount of decalin at
140–150°C over a period of 3–4 h. Calibration curves
(
were available for the determination of Mp. Each poly-
mer sample was weighed and measured twice to reduce
the error.
3.7. Synthesis of fluorenyl phenyl chloro phosphine (1)
3.4. Mass spectroscopy
At −78°C, 18.8 ml n-butyllithium (1.6 M in hexane)
were added dropwise to a solution of 5.0 g (30 mmol)
fluorene in 100 ml diethylether. The solution was stirred
for 6 h at room temperature. The solvent was evapo-
rated and the residue washed twice with 50 ml pentane
and then dried under high vacuum. Fluorenyllithium
remained as a yellow solid. At −78°C, the solids were
added to a solution of 8.07 g (45.0 mmol) phenyl
dichloro phosphine and 200 ml pentane. Immediately, a
white precipitate was formed. The reaction mixture was
stirred overnight at room temperature. For processing
and separation of unsubstituted and disubstituted side
products, the reaction mixture was filtered over sodium
sulfate, the residue washed twice with 20 ml pentane and
the product extracted with diethylether. After the sol-
vent was evaporated, the product remained as white
powder. Yield: 3.7 g (40%).
Routine measurements were performed with a Varian
MAT CH7 instrument (direct inlet system, electron
impact ionization 70 eV). GC/MS spectra were recorded
using a Varian 3700 gas chromatograph in combination
with a Varian MAT 312 mass spectrometer.
3.5. Gas chromatography
A Carlo Erba HRGC gas chromatograph with flame
ionization detector was used to analyze organic com-
pounds. The gas chromatograph was equipped with a 30
m long J&W fused silica column (DB1, film thickness
0.25 mm). Helium served as carrier gas; the flow through
the column was 3.8 ml min−1, split 1:30, septum flush-
ing 1.3 ml min−1. The following temperature program
was routinely used: 3 min at 50°C (starting phase), 5 K
min−1 (heating phase), 15 min at 310°C (plateau phase).
The retention time was indicated in seconds.
3.8. Synthesis of fluorenyl indenyl phenyl phosphine (2)
At −78°C, 4.0 ml n-butyllithium (1.6 M in hexane)
were added dropwise to a solution of 0.75 ml (6.5 mmol)
indene in 30 ml diethylether. The mixture was stirred for
6 h at room temperature. At −78°C, 2.0 g (6.5 mmol)
fluorenyl phenyl chloro phosphine (1) were added to the
solution and the reaction mixture was stirred overnight
at room temperature. For processing, the reaction mix-
ture was filtered over sodium sulfate, the residue washed
twice with 20 ml pentane and the product extracted with
toluene. After the evaporation of the solvent the
product remained as yellow powder. Yield: 1.25 g
(80%).
3.6. Characterization of the polymer samples
3.6.1. Differential scanning calorimetry
A Perkin Elmer DSC-7 calorimeter was available to
measure the thermal properties of the polymer samples.
Prior to the measurements, the polymer samples were
dried in vacuo. To determine the fusion enthalpies, 3–5
mg of the polymer were fused into standard aluminum
pans and measured using the following temperature
program: first heating phase (20 K min−1) from 50 to
200°C, first cooling phase (−20 K min−1) −50°C,