Complexes with Pt-Ru Bonds
Organometallics, Vol. 18, No. 11, 1999 2167
had been degassed with three freeze-pump-thaw cycles. The
resulting red-orange solution was allowed to warm to room
temperature and then stirred for 4 days. The solvent was
removed in vacuo, and the residue was chromatographed on
a silica gel column using CH2Cl2 as the eluent. The orange
band was isolated, and the solvent was removed in vacuo. The
residue was recrystalized from CH2Cl2/pentane and dried in
vacuo. Yield: 32 mg, 62%. Anal. Calcd for C56H44O6P4PtRu2:
C, 50.41; H, 3.32. Found: C, 50.29; H, 3.32. IR (Nujol): ν(CO)
2007 (s), 1960 (s), 1940 (sh), 1924 (s), 1893 (s), 1878 (b). NMR
the residue was separated by chromatography (silica gel, CH2-
Cl2/acetone 50:50), and the yellow band was isolated. The
solvent was removed in vacuo, and the residue was recrystal-
ized from CH2Cl2/Et2O. Yield: 85 mg, 74%. Anal. Calcd for
C
52H44Cl2O2P4PtRu: C, 52.40; H, 3.72; Cl, 5.95. Found: C,
52.35; H, 3.71; Cl, 5.81. IR: ν(CO) ) 2025 ss, 1945 ss,1905 sb,
1792 mb. NMR in CD2Cl2: δ(1H) ) 4.70 [m, 2H, PCHHP]; 4.09
1
[m, 2H, PCHHP]. δ(31P) ) 24.3 [m, RuP]; 11.6 [m, J (PtP) )
3060 Hz, PtP]. δ(13C) ) 208.0 [t, 2J (PC) ) 11 Hz, 1J (PtC) )
2
117 Hz]; 192.4 [m, J (PtC) ) 180 Hz].
2
in CD2Cl2: δ(1H) ) 4.48 [PCH2P, m]. δ(31P) ) 16.8 [d, J (PP)
X-r a y Str u ctu r e Deter m in a tion s. [P tRu 2(CO)5(µ-CO)-
(µ-d p p m )2] (4). Crystals of 4 were grown by slow diffusion of
pentane into a methylene chloride solution. A red crystal was
mounted on a glass fiber. Data were collected at 100 K on a
Nonius Kappa-CCD diffractometer using COLLECT (Nonius,
1998) software. The unit cell parameters were calculated and
refined from the full data set. Crystal cell refinement and data
reduction was carried out using the Nonius DENZO package.
The data were scaled using SCALEPACK (Nonius, 1998), and
no other absorption corrections were applied. The reflection
data and systematic absences were consistent with the mono-
clinic space group P21/n. The SHELXTL 5.03 (Sheldrick, G.
M., Madison, WI) program package was used to solve the
structure by direct methods and successive difference Fouriers.
All non-hydrogen atoms were refined with anisotropic thermal
parameters. The hydrogen atoms were calculated geometri-
cally and rode on their respective carbon atoms. The largest
residual electron density peak (1.523 e/Å3) was associated with
the platinum atom.
) 48 Hz, RuP], 8.3 [d, 2J (PP) ) 48 Hz, 1J (PtP) ) 3130 Hz,
3
PtP]. δ(13C) ) 204 [2C, dm, J (PC) ) 21 Hz, equatorial CO];
222 [4C, m, 1J (PtC) ) 34 Hz, axial CO]. If the reaction to form
complex 4 is carried out in situ in CD2Cl2, compound 5 is
observed by 31P NMR as a reaction intermediate.
[P tRu H(CO)3(µ-d p p m )2][Cl] (5). [Pt(dppm)2]Cl2 (30 mg,
0.028 mmol) and PPN[HRu(CO)4] (22 mg, 0.029 mmol) were
placed in an NMR tube and cooled to -80 °C. Deuterated
methylene chloride (0.5 mL) was then added to the tube,
resulting in the formation of an orange solution, which was
allowed to slowly warm to room temperature. Compound 5 is
stable in solution for several hours, but over longer periods it
is transformed into 6 and 7. Attempts to isolate solid samples
of 5 resulted in mixtures of 6 and 7. IR (CH2Cl2 solution): 2042
(m), 1988 (s), 1970 (sh). NMR in CD2Cl2: δ(1H) ) -3.95 [t,
2
1
1H, J (PH) ) 10 Hz, J (PtH) ) 1270 Hz, PtH]; 4.34 [m, 4H,
3J (PtH) ) 30 Hz, PCH2P]. δ(31P) ) 36.8 [m, RuP]; 24.0 [m,
1J (PtP) ) 3260, PtP]. δ(13C) ) 195.5 [t, 1C, J (PC) ) 14 Hz,
2
2J (PtC) ) 28 Hz, CO anti to Pt]; 207.8 [t, 2C, J (PC) ) 13 Hz,
[P t R u Cl2(CO)(µ-CO)(µ-d p p m )2] (7a ). Crystals of 7a ‚
CH2Cl2‚1/2pentane were grown by slow diffusion of pentane
into a methylene chloride solution. A crystal was mounted in
a capillary tube. Data were collected and treated as above.
Systematic absences were consistent with either Cc or C2/c,
but the noncentrosymmetric choice (Cc) had a better combined-
figure-of-merit. The choice was borne out by a successful
solution of the structure. Of the two solvent molecules, the
methylene chloride was well behaved, while the pentane was
disordered. It was modeled by fixing the R and â C-C bond
lengths. An extinction correction was applied, and the absolute
structure parameter was refined to a value of 0.334. The
largest residual electron density peak (1.299 e/Å3) was associ-
ated with the pentane of solvation. The crystal data and
refinement parameters are listed in Table 1. Selected inter-
atomic distances and angles are listed in Table 3.
2
CO syn to Pt].
[P tRu HCl(CO)(µ-CO)(µ-d p p m )2] (6). [Pt(dppm)2]Cl2 (100
mg, 0.096 mmol) was suspended in THF (50 mL). [PPN][HRu-
(CO)4] (72 mg, 0.096 mmol) was dissolved in THF (20 mL) and
added dropwise to the suspension over 30 min, resulting in a
bright yellow solution and a white precipitate. The solvent was
removed in vacuo, and the residue was extracted into THF (2
mL) and filtered. The solvent was removed from the filtrate
in vacuo, and the residue was recrystallized from THF/Et2O/
pentane and dried in vacuo. Yield: 111 mg. The sample
contained small amounts of a second compound, which was
shown to be [PtRu(Cl)2(CO)2(µ-dppm)2] (7). IR: ν(CO) ) 1880
sb, 1770 mb. NMR in CD2Cl2: δ(1H) ) -5.45 [tt, 1H, 2J (HPtP)
3
1
) 16 Hz, J (HPtRuP) ) 3 Hz, J (HPt) ) 1050 Hz, PtH]; 4.23
(m, 1H, CH2); 3.88 [m, 1H, 3J (PtH) ) 70 Hz, CH2]. δ(31P) )
38.0 [m, RuP]; 17.8 [m, 1J (PtP) ) 2940 Hz, PtP]. δ(13C) ) 207.7
[m, 1C]; 225.1 [m, 1C].
Ack n ow led gm en t. We thank the NSERC (Canada)
[P tRu Cl2(CO)2(d p p m )2] (7). PPN[HRu(CO)4] (72 mg, 0.096
mmol) was dissolved in CH2Cl2 (15 mL), and the solution was
cooled to -80 °C. This solution was then added to [Pt(dppm)2]-
[Cl2] (100 mg, 0.096 mmol) in CH2Cl2 (15 mL) also at -80 °C,
resulting in the formation of an orange solution. The solution
was allowed to gradually warm to room temperature and then
stirred for 4 days. The solvent was then removed in vacuo,
and the PRF for financial support.
Su p p or tin g In for m a tion Ava ila ble: Table of X-ray data
in CIF format are available on the web only. This material is
OM990032Z