1090 Organometallics, Vol. 25, No. 5, 2006
Ara et al.
IR (Nujol, cm-1): 791 and 779 (X-sensitive C6F5 group). 19F NMR
(PPh2C6F5)(µ-I)}2], 10, in keeping with the higher lability of
the palladium derivatives.
3
(293 K, CDCl3, 282.4 MHz, δ): -119.5 (4 o-F, JPt,F ) 300 Hz),
-157.7 (2 p-F), -162.0 (4 m-F) ppm. 31P{1H} NMR (293 K,
It is also noteworthy that although reduction to M(II)
complexes could also occur through the coupling of the PPh2
and I groups (formation of PPh2I), no evidence of such a process
has been obtained. In these complexes the formation of a P-C
bond is preferred to the formation of a P-I one.
The structural, bonding, electronic, and related properties of
all compounds studied herein have been satisfactory described
by DFT computational techniques at the B3LYP/lanl2dz level
of theory. The chemical behavior of the [(C6F5)2M(µ-PH2)2M′-
(NCCH3)2] (M ) M′ ) Pt or Pd, M ) Pt, M′ ) Pd) complexes
toward their reaction with I2 was also explained in the
framework of the qualitative frontier molecular orbital theory.
1
CDCl3, 121.5 MHz, δ): 280.5 (1JPt1,P ) 1135, JPt2,P ) 1716 Hz)
ppm.
M ) Pd, 5. To a yellow suspension of 2 (0.110 g, 0.101 mmol)
in CH2Cl2 (6 mL) at 195 K was added a CH2Cl2 solution (5 mL)
of I2 (0.025 g, 0.101 mmol). After 5 min stirring at 195 K the dark
brown solution was evaporated to 1 mL and a brown solid start to
crystallize. Hexane (4 mL) was added, and the solid 5 was filtered
off and washed with 1 mL of hexane (0.070 g, 55% yield). Anal.
Found (calcd for C36F10H20I2P2PtPd): C, 34.0 (34.3); H, 1.5 (1.6).
IR (Nujol, cm-1): 795 and 784 (X-sensitive C6F5 group). 19F NMR
(213 K, CD2Cl2, 282.4 MHz, δ): -119.1 (4 o-F, 3JPt,F ) 295 Hz),
-157.3 (2 p-F), -161.5 (4 m-F) ppm. 31P{1H} NMR (213 K, CD2-
Cl2, 121.5 MHz, δ): 321.5 (1JPt,P ) 1273 Hz) ppm.
Experimental Section
Reduction of [(C6F5)2Pt(µ-PPh2)2MI2] (M ) Pt 4, Pd 5). M
) Pt. To a red solution of 4 (0.100 g, 0.074 mmol) in CH2Cl2 (8
mL) was added a CH2Cl2 solution (1 mL) of NBu4BH4 (0.040 g,
0.155 mmol). The yellow solution was stirred for 3 h, then
General Procedures and Materials. C, H, and N analyses were
performed with a Perkin-Elmer 240B microanalizer. IR spectra were
recorded on a Perkin-Elmer Spectrum One spectrophotometer
(Nujol mulls between polyethylene plates in the range 4000-350
cm-1). NMR spectra were recorded on a Varian Unity 300
instrument with SiMe4, CFCl3, and 85% H3PO4 as external
references for 1H, 19F, and 31P, respectively. Conductivities (acetone
c ≈ 5 × 10-4 M) were measured with a Philips PW 9509
conductimeter. Literature methods were used to prepare the starting
complexes [(C6F5)2Pt(µ-PPh2)2Pt(NCCH3)2],21 [NBu4]2[(C6F5)2Pt-
(µ-PPh2)2Pd(C6F5)2],19 and [NBu4][(C6F5)2Pd(µ-PPh2)2Pd(acac)].20
Safety Note. Perchlorate salts of metal complexes with organic
ligands are potentially explosive. Only small amounts of materials
should be prepared, and these should be handled with great caution.
Synthesis of [(C6F5)2Pt(µ-PPh2)2Pd(NCCH3)2] (2). To a yellow
solution of [NBu4]2[(C6F5)2Pt(µ-PPh2)2Pd(C6F5)2] (0.300 g, 0.164
mmol) in acetonitrile (15 mL) was added HClO4 (0.327 mmol,
MeOH solution), and a yellow solid, 6, starts to crystallize. After
1.5 h stirring at room temperature the mixture was evaporated to 3
i
evaporated to 1 mL. PrOH (4 mL) was added, and after 15 min
stirring a yellow solid, 6, was filtered off and washed with 2 × 0.5
i
mL of PrOH (0.076 g, 70% yield). Anal. Found (calcd for
C104F20H112I2P4Pt4): C, 42.8 (42.7); H, 4.0 (3.85); N, 1.2 (0.95).
ΛM ) 186 ohm-1 cm2 mol-1. IR (Nujol, cm-1): 782 and 773 (X-
sensitive C6F5 group). 19F NMR (213 K, deuteroacetone, 282.4
MHz, δ): -114.0 (8 o-F, 3JPt,F ) 320 Hz), -166.2 (8 m-F), -167.2
(4 p-F) ppm. 31P{1H} NMR (213 K, deuteroacetone, 121.5 MHz,
δ): -142.3 (1JPt,P ) 1897 and 2447 Hz) ppm.
M ) Pd, 5. The same procedure used for reduction of 4 from 5
(0.100 g, 0.079 mmol) and NBu4BH4 (0.045 g, 0.174 mmol) gives
a black solid, from which complex 7 is identified by spectroscopy.
Synthesis of [NBu4]2[{(C6F5)Pt(µ-PPh2)2Pd(µ-I)}2], 7. To a
yellow solution of [NBu4]2[{(C6F5)Pt(µ-PPh2)2Pd(µ-Cl)}2] (0.160
g, 0.062 mmol) in acetone (20 mL) was added KI (0.096 g, 0.578
mmol). The mixture was stirred at room temperature for 20 h and
evaporated to dryness. The solid was extracted with CH2Cl2 (20
mL), and the solution was evaporated to ca. 1 mL. iPrOH (10 mL)
was added, and after 3 h stirring an orange solid, 7, was filtered
i
mL, and PrOH (3 mL) was added. 6 was collected by filtration
and washed with 2 × 0.5 mL of iPrOH (0.135 g, 76% yield). Anal.
Found (calcd for C40F10H26N2P2PtPd): C, 44.6 (44.8); H, 2.1 (2.4);
N, 2.45 (2.6). IR (Nujol, cm-1): 786 and 774 (X-sensitive C6F5
group);26,27 2313, 2286 (νNtC).53 19F NMR (293 K, deuteroacetone,
282.4 MHz, δ): -114.6 (4 o-F, 3JPt,F ) 327 Hz), -162.4 (6 m- +
p-F) ppm. 31P{1H} NMR (293 K, deuteroacetone, 121.5 MHz, δ):
-130.4 (1JPt,P ) 1785 Hz) ppm.
i
off and washed with 3 × 0.5 mL of PrOH (0.109 g, 64% yield).
Anal. Found (calcd for C104F20H112I2P4Pt2Pd2): C, 45.5 (45.4); H,
4.25 (4.1); N, 1.0 (1.0). ΛM ) 181 ohm-1 cm2 mol-1. IR (Nujol,
cm-1): 785 and 780 (X-sensitive C6F5 group). 19F NMR (213 K,
3
deuteroacetone, 282.4 MHz, δ): -113.6 (8 o-F, JPt,F ) 327 Hz),
-166.2 (8 m-F), -167.2 (4 p-F) ppm. 31P{1H} NMR (213 K,
deuteroacetone, 121.5 MHz, δ): -131.4 (1JPt,P ) 1733 Hz)
ppm.
Synthesis of [(C6F5)2Pd(µ-PPh2)2Pd(NCCH3)2] (3). To a yellow
solution of [NBu4][(C6F5)2Pd(µ-PPh2)2Pd(acac)] (0.440 g, 0.350
mmol) in acetonitrile (5 mL) was added HClO4 (0.350 mmol,
MeOH solution). After 30 min stirring the mixture was evaporated
Synthesis of [{(C6F5)M(µ-PPh2)(µ-I)M′(PPh2C6F5)(µ-I)}2] (M
) M′ ) Pt, 8; M ) Pt, M′ ) Pd, 9; M ) M′ ) Pd, 10). M ) M′
) Pt, 8. A red CH2Cl2 solution (15 mL) of 4 (0.150 g, 0.111 mmol)
was stirred at room temperature for 60 h. The resulting yellow
solution was evaporated to 1 mL, and 8 crystallized as a yellow
solid. Hexane (4 mL) was added, and the solid was filtered off
(0.099 g, 66% yield). Anal. Found (calcd for C72F20H40I4P4Pt4):
C, 32.4 (32.1); H, 1.3 (1.5). IR (Nujol, cm-1): 1522 and 983
(PPh2C6F5); 799 (X-sensitive C6F5 group). 19F NMR (293 K, CD2-
Cl2, 282.4 MHz, δ): -112.9 (2 o-F), -119.0 (2 o-F), -124.2 (2
o-F, PPh2C6F5), -147.9 (2 p-F, PPh2C6F5), -160.2 (4 m-F,
PPh2C6F5), -164.3 (2 p-F), -165.2 (2 m-F), -166.4 (2 m-F) ppm.
31P{1H} NMR (213 K, CDCl3, 121.5 MHz, δ): -1.0 (PPh2C6F5,1JPt,P
) 4684 Hz), -59.7 (PPh2,1JPt,P ) 2592 and 3287 Hz) ppm.
M ) Pt, M′ ) Pd, 9. Complex 9 was prepared in the same way
as for 5 (0.100 g, 0.079 mmol) with 15 h stirring at room
temperature. 9 was formed as a brown solid (0.070 g, 70% yield).
Anal. Found (calcd for C72F20H40I4P4Pd2Pt2): C, 34.2 (34.3); H,
1.9 (1.6). IR (Nujol, cm-1): 1520 and 983 (PPh2C6F5); 804 (X-
sensitive C6F5 group).
i
to ca. 2 mL and PrOH (3 mL) was added. A yellow solid, 6,
crystallized, which was collected by filtration and washed with 0.5
i
mL of PrOH (0.262 g, 75% yield). Anal. Found (calcd for
C40F10H26N2P2Pd2): C, 47.8 (48.1); H, 2.4 (2.6); N, 2.8 (2.8). IR
(Nujol, cm-1): 773 and 763 (X-sensitive C6F5 group); 2317, 2290
(νNtC). 19F NMR (293 K, deuteroacetone, 282.4 MHz, δ): -111.5
(4 o-F), -164.6 (2 p-F), -164.9 (4 m-F) ppm. 31P{1H} NMR (293
K, deuteroacetone, 121.5 MHz, δ): -106.0 ppm.
Synthesis of [(C6F5)2Pt(µ-PPh2)2MI2] (M ) Pt 4, Pd 5). M )
Pt. To a white suspension of 1 (0.200 g, 0.170 mmol) in CH2Cl2
(5 mL)/acetonitrile (8 mL) at 213 K was added an acetonitrile
solution (8 mL) of I2 (0.046 g, 0.181 mmol). The color of the
suspension turned red, and after 20 min stirring at 213 K the mixture
was evaporated to 5 mL. The dark red solid, 4, was filtered off
and washed with 0.5 mL of cold iPrOH (0.179 g, 78% yield). Anal.
Found (calcd for C36F10H20I2P2Pt2): C, 32.0 (32.1); H, 1.3 (1.5).
(53) Murahashi, T.; Nagai, T.; Okuno, T.; Matsutani, T.; Kurosawa, H.
Chem. Commun. 2000, 1689-1690.