A. Romerosa et al. / Inorganica Chimica Acta 353 (2003) 145ꢂ
/150
149
recorded on a Bruker AVANCE DRX 300 spectro-
meter. Peak positions are relative to tetramethylsilane
(1H, 13C{1H}) and were calibrated with respect to the
residual protonated solvent (1H) or to the solvent
resonance (13C). The 31P{1H} NMR spectra are given
with respect to external 85% H3PO4 in D2O with
downfield values taken as positive. Infrared spectra
were recorded (on KBr discs) on a IR-ATI Mattson
Infinity Series. Elemental analysis (C, H, N, S) were
performed on a Fisons Instruments EA 1108 elemental
analyzer. GC/MS analyses were carried out using a
Varian GC/MS Saturn 3 gas chromatograph-ion-trap
mass spectrometer, using a stationary phase column
to ride on their parent C atoms with Uiso(H)ꢀ
for methyl groups, and 1.2Ueq(C) for the phenyl and
/
1.5Ueq(C)
methylene groups. Idealized CÃH distances were fixed
/
˚
at 0.98, 0.95 and 0.99 A, respectively. Hydrogen atoms
corresponding to the water molecules were neither
located nor geometrically placed.
4.3. Synthesis of [PdCl(Py)(PPh3)(8-MTT)]×
(1)
/H2O
The complex trans-[PdCl(PPh3)2(8-MTT)] (0.1 g,
0.0112 mmol) was dissolved in 3 ml of pyridine at
50 8C. After 1 h the orange solution was cooled down to
room temperature and the solvent removed under
vacuum. The orange solid obtained was recrystallized
from CHCl3/pentane. The microcrystalline powder was
DB-5MS (J&W Scientific, Folsom, CA), 30 mꢄ
/
0.25
mm i.d.ꢄ0.25 mm film thickness.
/
4.2. X-ray crystallography
filtered out, washed with pentane (2ꢄ/1 ml), and air
dried.
Yield: 68%. Anal. Calc. for C31H31ClN5O3-
PPdS(726.41): C, 51.2; H, 4.3; N, 9.6; S, 4.4. Found:
A yellow crystal for the X-ray diffraction experiment
(0.42ꢄ0.18ꢄ0.18 mm) was obtained from a solution of
[PdBr(Py)(PPh3)(8-BzTT)] (2) in CHCl3 by slow eva-
poration of the solvent. Single crystal structure deter-
mination of 2 was carried out at 120 K from data
/
/
C, 50.8; H, 4.6; N, 9.2; S, 4.1. IR (cmꢁ1): n(C6Ä
/
O) 1702
N) 1603 (s), 1556
(s). 1H NMR (22 8C, CDCl3): 2.41 (s, SÃ
CH3, 3H), 3.15
(s, N1ÃCH3, 3H), 3.27 (s, N3ÃCH3, 3H), 7.12ꢂ8.10 (m,
Ph, 15H). 31P{1H} NMR (22 8C, CDCl3): 27.45 ppm.
1H NMR (50 8C, Py-d5): 2.43 (s, SÃ
CH3, 3H), 3.51 (s,
8.10 (m, Ph,
(s); n(C2Ä
/
O) 1649 (s). n(CÄ
/
C)ꢃ
/
n(CÄ
/
/
collected using graphite monochromated Mo Ka radia-
/
/
/
˚
0.71073 A) on a Bruker SMART-1K CCD
tion (lꢀ
/
detector diffractometer equipped with a Cryostream N2
open flow cooling device [13]. Series of narrow v-scans
(0.38, 20 s scanꢁ1) were performed at several 8-settings
in such a way as to cover a sphere of data to a maximum
/
N1Ã
/
CH3, 3H), 3.66 (s, N3Ã
/
CH3, 3H), 7.12ꢂ
/
15H). 31P{1H} NMR (50 8C, Py-d5): 27.69 ppm.
˚
resolution of 0.70 A. Cell parameters were determined
4.4. NMR study of the reaction between trans-
[PdCl(PPh3)2(8-MTT)] and Py-d5
and refined using the SMART software [14] from the
centroid values of 675 reflections with 2u values between
25.68 and 45.68. Raw frame data were integrated using
the SAINT program [15]. The structure was solved using
Direct Methods and refined by full-matrix least-squares
on F2 using SHELXTL [16]. The reflection intensities were
corrected for absorption effects by numerical integration
based on measurements and indexing of the crystal
faces, using SHELXTL software [16].
4.4.1. A: Under inert atmosphere
Into a 5 mm NMR tube were introduced trans-
[PdCl(PPh3)2(8-MTT)] (15 mg, 0.017 mmol) and 0.5 ml
of Py-d5. The first 31P{1H} NMR recorded at room
temperature showed no signals apart from those due to
the starting compound. As the temperature raised to
50 8C, after 5 m, an orange solution was obtained,
whose 31P{1H} NMR spectrum contained three singlets
The compound crystallizes in the monoclinic system,
˚
space group P21/c, with aꢀ
/
11.121(3) A, bꢀ
/
15.623(4)
at 27.72, 22.08 and ꢁ
within 12 h at 50 8C. The study of this solution in the
range from 50 to ꢁ60 8C revealed that the signals at
27.72 and ꢁ5.42 ppm were disappearing as the tem-
perature went down, being not observable at ꢁ20 8C.
From ꢁ20 to 50 8C both signals displayed the same
integral. The GCꢂMS analysis of the solution revealed
the presence of free PPh3 in the solution, to which the
/
5.42 ppm, which did not change
3
˚
˚
˚
A, cꢀ
g cmꢁ3 and mꢀ
collected and 10 395 unique reflections (Rint
were used in all calculations (2umax 61.01, hꢀ
15, kꢀ 22 to 21, lꢀ 30ꢂ29). From these, 8697
reflections were considered ‘observed’ (I ꢀ2s(I)). The
/
21.331(5) A, Uꢀ
1.757 mmꢁ1. 46 562 reflections were
0.0433)
14ꢂ
/
3638(2) A , Zꢀ
/
4, Dcalc
ꢀ
/
1.579
/
/
ꢀ
/
/
ꢀ
/
/
ꢁ
/
/
/
/
ꢁ
/
/
ꢁ
/
/
/
/
/
final wR(F2) was 0.1442 (all data) and the final R(F)
was 0.0543 (observed data). All non-hydrogen atoms
were refined with anisotropic atomic displacement
parameters (adps), except the two oxygens of two highly
disordered water molecules. These two oxygens were
refined as disordered over six different positions, all
sharing the same isotropic displacement parameter, with
the sum of their occupancies restrained to be 2.
Hydrogen atoms were geometrically placed and allowed
signal at ꢁ5.42 ppm was assigned. After removal of Py-
/
d5 under vacuum and addition of CDCl3, a new 31P{1H}
NMR spectrum showed the starting compound as the
only one present.
4.4.2. B: Under oxygen
The previous experiment was reproduced under air
atmosphere. In the first instance, the 31P{1H} NMR of
Romerosa, Antonio
