3690
S.I. Pascu et al. / Inorganica Chimica Acta 359 (2006) 3677–3692
inert atmosphere dry box. Inert gases were purified firstly by
passage through columns filled with activated molecular
sieves (4 A) and then either manganese (II) oxide suspended
a purple solution. Removal of the volatiles under reduced
pressure gave [Pd2(l-Br)2{Ph2PCH@C(Ph)N(2,6-iPr2-
C6H3)}2] (3) as a green solid.
˚
on vermiculite, for the Schlenk line, or BASF catalyst, for
the dry box. Celite filtration aid was purchased from Fluka
Chemie and oven-dried at 150 °C prior to use. Solvents were
Spectroscopic data for [Pd2(l-Br)2{Ph2PCH@C
(Ph)N(2,6-iPr2C6H3)}2] (3). Elemental analysis Calc.: C,
59.23; H, 5.13; N, 2.16. Found: C, 58.6; H, 5.3; N, 2.05%.
Mass spectrum (FAB+) m/z 1307.93(100) [M + H]+.
1H NMR (500 MHz, CD2Cl2): 1.45 (d, CH3CHCH3,
˚
pre-dried over activated 4 A molecular sieves and then
distilled under N2 from Na/K alloy (light petroleum ether
b.p. 40–60 °C, diethyl ether, pentane), from sodium (tolu-
ene), from potassium (THF), or from calcium hydride
(dichloromethane). Deuterated NMR solvents (Aldrich,
Goss Scientific) were refluxed and distilled from potassium
metal (d8-toluene) or stirred overnight with calcium hydride
(CD2Cl2) prior to use. Microanalyses were performed by
the microanalytical laboratory of the Inorganic Chemistry
Laboratory, University of Oxford and FAB+ mass-spectra
by the EPSRC National Mass Spectrometry Service Centre,
University of Wales, Swansea, UK.
NMR spectra were recorded using either a Varian Mer-
cury-vx 300 (1H 300 MHz, 13C 75.5 MHz, 19F 282.3 MHz,
31P 121.6 MHz) or a Varian UNITY plus (1H 500 MHz,
11B 160.4 MHz, 13C 125.7 MHz, 31P 202.4 MHz) spectrom-
eter and are at room temperature unless otherwise stated.
The spectra were referenced internally relative to the resid-
ual protio-solvent (1H) and solvent (13C) resonances rela-
tive to tetramethylsilane (1H, 13C, d = 0) or externally to
BF3 Æ Et2O (11B, d = 0); H3PO4 (31P, d = 0) or CFCl3
(19F, d 0). Chemical shifts (d) are expressed in ppm and
coupling constants (J) in Hz.
3
3
12H, JHH = 6.8), d = (d, CH3CHCH3, 12H, JHH = 6.8),
3
3.43 (h, CH3CHCH3, 4H, JHH = 6.8), 3.49 (d, CHP, 2H,
3JPH = 8.5 Hz,), 6.80 (d, 4 H, m-H of 2,6-iPr2C6H3), 7.03
(t, 2H, p-H of 2,6-iPr2C6H3), 7.05 (m, 4H, m-H of Ph-C),
7.18 (m, 2H, p-H of Ph-C), 7.23 (m, 4H, o-H of Ph-C),
7.44 (m, 8H, m-H of PPh2), 7.52 (m, 4H, p-H of PPh2),
7.75 (m, 8H, o-H of PPh2).
13C{1H} NMR (125.7 MHz, CD2Cl2): 23.6 (s,
CH3CHCH3), 24.8 (s, CH3CHCH3), 28.5 (s, CH3CHCH3),
1
2
72.1 (d, CH–P, JPC = 65 Hz), 177.6 (d, N@C, JPC = 23),
i
i
145.2 (s, i-C of Pr2C6H3N), 139.7 (s, o-C of Pr2C6H3N),
i
i
127.1 (s, m-C of Pr2C6H3N), 123.1 (s, p-C of Pr2C6H3N),
132.9 (b, i-C of Ph), 130.9 (s, o-C of Ph), 128.6 (s, m-C of
Ph), 128.4 (s, p-C of Ph), 132.5 (d, o-C of PPh2, 2JPC = 11),
3
129.5 (d, m-C of PPh2, JPC = 12), 133.2 (d, p-C of PPh2,
2JPC = 11).
31P{1H} NMR (202.4 MHz, CD2Cl2): 53.8 (s).
5.1.2. Reaction between [Pd2(l-Br)2{Ph2PCH@C(Ph)-
N(2,6-Me2C6H3)}2] (4), AgBF4 and MeOH
The solids [Pd2(l-Br)2{Ph2PCH@C(Ph)N(2,6-Me2-
C6H3)}2] (4) (0.015 g, 0.0127 mmol) and AgBF4 (0.007 g,
0.0253 mmol) were mixed in a Schlenk tube and a mixture
of 25 mL CH2Cl2 and 1 mL MeOH was added via cannulae.
The reaction mixture was stirred for 1 h at room temperature
which gave a black residue and a yellow supernatant. The
black residue formed was removed by filtration. The yellow
supernatant was concentrated under reduced pressure to
about 5 mL and layered with pentane. After storing for 2
days at 0 °C, yellow-orange crystals were isolated from the
mixture and characterised as [Pd{Ph2PCH2C(Ph)@N(2,6-
Me2C6H3)}]2[BF4]2 (6). Yield 30%.
GC–MS chromatographs and spectra were recorded
using a Hewlett-Packard 5890 Gas Chromatograph fitted
with a non-polar column connected to a Trio-1000 Mass
Spectrometer operating Electron Impact (70 eV) and chem-
ical ionisation (CI) mode (NH3) and detecting positively
charged species. The temperature profile for the GC is:
100 °C (3 min), then 10 °C/min ramp until 280 °C (held
for 10 min).
Complexes [PdBr2{Ph2PCH2C(Ph)@N(2,6-iPr2C6H3)}]
(1), [PdBr2{Ph2PCH2C(Ph)@N(2,6-Me2C6H3)}] (2) and
[Pd2(l-Br)2{Ph2PCH@C(Ph)N(2,6-Me2C6H3)}2] (4) have
been prepared following established procedures [34,35].
All new compounds were characterised by elemental anal-
Spectroscopic data for [Pd2{Ph2PCH2C(Ph)@N(2,6-
Me2C6H3)}2][BF4]2 (6). Elemental analysis Calc.: C,
56.0; H, 4.4; N, 2.3. Found: C, 55.4; H, 4.32; N, 1.92%.
1
ysis, FAB mass spectrometry, H, 31P (and where applica-
ble 19F and 11B8 NMR spectroscopy). In the case of 3, 4b
(the second polymorph of 4) and 6 the X-ray diffraction
structures were determined.
Mass spectrum (FAB+) m/z 1026.6 (45) [M ꢀ 2BF4]2+
,
IR (CD2Cl2)mC@N 1538 cmꢀ1, mBF 1400 cmꢀ1
.
4
1H NMR data (500 MHz, CD2Cl2) 2.30 (s, 12H,
2
Me2C6H3), 5.17 (d, 4H,CH2–P, JPH = 13.4), 6.90 (b, 2H,
5.1.1. Reaction between
p-H of Me2C6H3), 6.86 (d, 4H, m-H of Me2C6H3,
3JHH = 7.6), 7.25 (m, 4H, o-H of Ph), 7.10 (m, 4H, m-H
of Ph), 7.32 (m, 2H, p-H of Ph), 7.61 (m, 4H, o-H of
[PdBr2{Ph2PCH2C(Ph)@N(2,6-iPr2C6H3)}] (1) and KH
[PdBr2{Ph2PCH2C(Ph)@N(2,6-iPr2C6H3)}] (1) (0.11 g,
0.15 mmol) and KH (0.006 g, 0.15 mmol) were mixed in a
Schlenk tube and 50 mL cold THF was added whilst stir-
ring at ꢀ78 °C. The reaction mixture was left stirring to
reach room temperature over 12 h. The volatiles were
removed under reduced pressure and the residue washed
with 100 mL of pentane which gave a dark grey solid.
The solid was extracted with 50 mL CH2Cl2 which gave
3
PPh2, JPH = 13.4), 7.46 (m, 4H, m-H of PPh2,
4JPH = 2.7), 31P{1H} NMR data (202.4 MHz, CD2Cl2)
47.9 (s), 11B{1H} NMR data (160.4 MHz, CD2Cl2) ꢀ0.2
(s), 19F NMR data (282.45 MHz, CD2Cl2) ꢀ150.0 (s),
13C{1H} NMR data (125.7 MHz, CD2Cl2): 19.0 (s,
Me2C6H3N), 68.4 (b, CH2–P), 133–125 (12 aromatic-C
resonances).