3804
A. de León et al. / Inorganica Chimica Acta 362 (2009) 3801–3806
Table 2
(0.011 g) of pyridine were added. Immediately after, a solution of
0.15 mmol (0.030 g) of AgBF4 in methanol (2 ml) was added under
vigorous stirring. After 5 min, stirring was stopped, and AgCl was
filtered off through a Celite pad. The solvent was partially removed
under vacuum, until the product precipitated as a yellow solid.
This solid was filtered, washed in dichloromethane and dried un-
der vacuum.
Selected bond lengths (Å) and bond angles (°) for [2](BF4)2ꢁ0.5 H2O.
Pd–N(1)
Pd–N(4)
2.034(2)
2.057(2)
Pd–P
Pd–S
2.3229(9)
2.3785(9)
N(1)–Pd–N(4)
N(1)–Pd–P
N(4)–Pd–P
173.87(8)
89.47(5)
95.78(7)
N(1)–Pd–S
N(4)–Pd–S
P–Pd–S
80.42(6)
93.75(7)
163.50 (2)
Yield: 0.021 g (24%). Anal. Calc. for C19H27B2F8N5PdS: C, 35.79;
H, 4.27; N, 10.98; S, 5.03. Found: C, 35.76; H, 4.25; N, 10.97; S,
5.12%. MS(ESI): m/z (%) = 320 (23) [Pd(medꢀ)+CH3CN+2H2O]+;
The Pd–Npz (2.034(2) Å and 2.057(2) Å) and Pd–PPh3
(2.3229(9) Å) bond lengths are of the same order as those found
in the literature. For the Pd–Npz bonds, the literature describes dis-
tances between 1.979 and 2.141 Å [13], and for Pd–PPh3 the bond
distances are between 2.286 and 2.343 Å [4,12]. The Pd–S(thioe-
ther) bond distance (2.3785(9) Å) is longer than that found for
the analogous complex [PdCl(bdtp)](BF4) (2.308(2) Å) [3g], show-
ing the differentiated thermodynamic trans-effect provoked by
chlorine or PPh3 ligands [14].
The bdtp ligand acts as a tridentate chelate, and forms two
PdNNCCS six-membered rings with twist boat conformation. Bite
angles are 93.75(7)° and 80.42(6)° for N(4)–Pd–S and N(1)–Pd–S,
respectively. These bite angles are not similar to those reported
for [PdCl(bdtp)](BF4), (N–Pd–S bites angles are 90.5(2)° and
88.5(2)°) [3g], probably due to the steric hindrance provoked by
the PPh3 ligand.
157 (100) [Hmed+H]+. Conductivity
(X
ꢀ1 cm2 molꢀ1
(C–H)ar, 2965,
(C@C), (C@N))pz
(B–F), 816 (d(C–H)oop py,
(Polyethylene, cmꢀ1): 470, 445
(Pd–N)ar, 334
(Pd–S). 1H NMR (CD3CN solution, 250 Hz, 298 K) d: 8.41, 8.24,
,
1.27 ꢂ
10ꢀ3 M in acetonitrile): 279. IR (KBr, cmꢀ1): 3142
2907 (C–H)al, 1605 ( (C@C), (C@N))py, 1553 (
1449, 1422 (d(C@C), d(C@N))ar, 1036
768 (d(C–H)oop pz.
m
m
m
m
m
m
,
m
)
)
m
m
7.75 [5H, m, py], 6.01 [2H, s, CH(pz)], 4.64 [2H, ddd, 2J = 14.20 Hz,
3J = 3.60 Hz, 3J = 2.67 Hz, NpzCH2CH2S], 4.54 [2H, ddd, 2J =
14.20 Hz, 3J = 11.22 Hz, 3J = 1.50 Hz, NpzCH2CH2S], 3.16 [2H, ddd,
2J = 15.50 Hz, 3J = 2.67 Hz, 3J = 11.22 Hz, NpzCH2CH2S] 2.74 [2H,
ddd, 2J = 15.50 Hz, 3J = 3.60 Hz, 3J = 1.50 Hz, NpzCH2CH2S], 2.46
[6H, s, CH3(pz)], 2.16 [6H, s, CH3(pz)] ppm. 13C{1H} NMR (CD3CN
solution, 63 MHz, 298 K) d: 154.4 (pz-C), 146.2 (pz-C), 154.0–
126.2 (py), 109.4 (CH(pz)), 51.3 (NpzCH2CH2S), 40.0 (NpzCH2CH2S),
15.5 (CH3(pz)), 11.9 (CH3(pz)) ppm.
3. Conclusion
4.2.2. Synthesis of the complex [Pd(bdtp)(PPh3)](BF4)2 ([2](BF4)2)
A solution of 0.10 mmol (0.051 g) of [PdCl(bdtp)](BF4) was dis-
solved in a mixture of dichloromethane (10 ml), methanol (8 ml)
and acetonitrile (5 ml). Then, a solution of 0.10 mmol (0.020 g) of
AgBF4 in methanol (2 ml) was added dropwise with vigorous stir-
ring. After 5 min, stirring was stopped, and AgCl was filtered off
through a Celite pad. Then, a solution of 0.10 mmol (0.026 g) of
PPh3 in methanol (5 ml) was added. When the volume of the resul-
tant solution had been reduced to roughly 5 ml, the product pre-
cipitated as a yellow solid. This solid was filtered off, washed in
dichloromethane and dried under vacuum.
The present paper reports the reaction of complex
[PdCl(bdtp)](BF4) with pyridine, triphenylphosphine, cyanide, thio-
cyanate or azide, in the presence of AgBF4 or NaBF4. The chlorine li-
gand is replaced by these neutral (pyridine, triphenylphosphine) or
anionic ligands (cyanide, thiocyanate, azide) to yield the complexes
[Pd(bdtp)(X)](BF4)2 (X = py, PPh3), and [Pd(X)(bdtp)](BF4) (X = CNꢀ,
SCNꢀ, N3ꢀ). In these complexes, the bdtp ligand shows tridentate
coordination (NSN). The NMR studies of the complexes prove the ri-
gid conformation of the ligands once they have been complexed.
Yield: 0.072 g (88%). Anal. Calc. for C32H37B2F8N4PdPSꢁ0.5H2O:
C, 46.32; H, 4.62; N, 6.75; S, 3.86. Found: C, 46.20; H, 4.91; N,
6.50; S, 3.62%. MS(ESI): m/z (%) = 704 (100) [Pd(bdtp)(PPh3)+H2O+
4. Experimental
4.1. General details
CH3CNꢀH]+). Conductivity (
X
ꢀ1 cm2 molꢀ1, 1.09 ꢂ 10ꢀ3 M in ace-
tonitrile): 300. IR (KBr, cmꢀ1): 3049
m(C–H)ar, 2967, 2922 m(C–
The reactions were carried out under nitrogen atmosphere using
vacuum line and Schlenk techniques. All reagents were commercial
grade materials and were used without further purification. Sol-
vents were dried and distilled according to standard procedures
and stored under nitrogen. Samples of [PdCl(bdtp)](BF4) were pre-
pared as described in the literature [3g]. Elemental analyses (C, H,
N, S) were carried out by the staff of Chemical Analyses Service of
the Universitat Autònoma de Barcelona on a Carlo Erba CHNS EA-
1108 instrument. Conductivity measurements were performed at
room temperature (r.t.) in 10ꢀ3 M acetonitrile solution, employing
a CyberScan CON 500 (Eutech instrument) conductimeter. Infrared
spectra were run on a Perkin–Elmer FT spectrophotometer, series
2000 cmꢀ1 as KBr pellets or polyethylene films in the range 4000–
250 cmꢀ1. 1H NMR, 13C{1H} NMR, 31P{1H}, HSQC, COSY, and NOESY,
spectra were recorded on a NMR-FT Bruker AC-250 MHz spectrom-
eter in CD3CN or (CD3)2CO solutions. All chemical shifts values (d)
are given in ppm. Mass spectra were obtained with an Esquire
3000 ion-trap mass spectrometer from Bruker Daltonics.
H)al, 1554 (
1059 (B–F), 810 d(C-H)oop, 696
(Pd–N), 421 (Pd–P), 357
(Pd–S). 1H NMR (CD3CN solution,
m
(C@C),
m
(C@N))ar, 1467, 1438 (d(C@C), d(C@N))ar,
m
m
(P–C). (Polyethylene, cmꢀ1): 455
m
m
m
250 Hz, 298 K) d: 7.74 [3H, m, ortho-H, PPh3], 7.60 [12H, m,
PPh3], 6.04 [2H, s, CH(pz)], 5.14, 5.00 [2H/2H, m, NpzCH2CH2S],
3.75, 3.31 [2H/2H, m, NpzCH2CH2S], 2.51 [6H, s, CH3(pz)], 2.39
[6H, s, CH3(pz)] ppm. 13C{1H}NMR (CD3CN solution, 63 MHz,
298 K) d: 152.2 (pz-C), 145.1 (pz-C), 135.4-128.4 (PPh3), 109.5
(CH(pz)), 51.4 (NpzCH2CH2S), 40.0 (NpzCH2CH2S), 16.1 (CH3(pz)),
12.4 (CH3(pz)) ppm. 31P{1H} NMR (CDCl3 solution, 81 MHz) d:
21.1 (s, PPh3).
4.2.3. Synthesis of [Pd(CN)(bdtp)](BF4) ([3](BF4))
A solution of 0.13 mmol (0.025 g) of AgBF4 in methanol (5 ml)
was added dropwise under vigorous stirring to a solution of
0.12 mmol (0.061 g) of [PdCl(bdtp)](BF4) in dichloromethane
(10 ml) and acetonitrile (5 ml). After 5 min, stirring was stopped,
and AgCl was filtered off through a Celite pad. A solution of
0.12 mmol (0.006 g) of NaCN in methanol (5 ml) was then added.
The resulting solution was stirred at room temperature for 12 h.
The solution was concentrated until a yellow crystalline precipitate
appeared. The solid was filtered off, washed with diethyl ether
(5 ml) and dried under vacuum.
4.2. Synthesis of the complexes
4.2.1. Synthesis of the complex [Pd(bdtp)(py)](BF4)2 ([1](BF4)2)
To a solution of 0.14 mmol (0.071 g) of [PdCl(bdtp)](BF4) dis-
solved in a mixture of CH2Cl2:methanol (1:1) (10 ml), 0.14 mmol