Access to unsaturated ruthenium complexes via phosphine complexation with triphenylborane: Synthesis and structure of a zwitterionic arene complex, (η6-Ph-BPh2H)Ru(PMe3)2(SiMe 3)

Article abstract of DOI:10.1021/om9908938

Triphenylborane, BPh₃, serves as a phosphine sponge , scavenging free PMe₃ from alkane solutions of the 18e^- complex (PMe₃)₄Ru(SiMe₃)H to form sparingly soluble Ph₃B-PMe₃ and the 16e^- (PMe₃)₃Ru(SiMe₃)H. Under nitrogen atmosphere the 16e^- (PMe₃)₃Ru(SiMe₃)H forms a dimeric N₂ adduct, [(PMe₃)₃Ru(SiMe₃)H]₂N₂. Both the 16e^- complex and its N₂ adduct exist in equilibrium with the 18e^- silene complex, (PMe₃)₃Ru(CH₂=SiMe₂)H₂. However, long reaction times in the presence of excess borane leads to removal of another phosphine ligand as Ph₃B-PMe₃ and formation of a new zwitterionic complex, (η⁶-PhBPh₂H)Ru(PMe₃)₂(SiMe ₃) (5), in which a molecule of borane has abstracted a ruthenium hydride ligand and also coordinates as an η⁶-arene. The merits and limitations of BPh₃ as a phosphine removal agent are discussed. Compound 5 has been characterized by single-crystal X-ray analysis and exhibits unusually long Ru-C_arene bonds.

Full text of DOI:10.1021/om9908938

3374
Organometallics 2000, 19, 3374-3378
Access to Un sa tu r a ted Ru th en iu m Com p lexes via
P h osp h in e Com p lexa tion w ith Tr ip h en ylbor a n e:
Syn th esis a n d Str u ctu r e of a Zw itter ion ic Ar en e
Com p lex, (η6-P h -BP h 2H)Ru (P Me3)2(SiMe3)
Vladimir K. Dioumaev, Karl Plo¨ssl, Patrick J . Carroll, and Donald H. Berry*
Department of Chemistry and Laboratory for Research on the Structure of Matter,
University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323
Received November 8, 1999
Triphenylborane, BPh3, serves as a phosphine “sponge”, scavenging free PMe3 from alkane
solutions of the 18e- complex (PMe3)4Ru(SiMe3)H to form sparingly soluble Ph3B-PMe3 and
the 16e- (PMe3)3Ru(SiMe3)H. Under nitrogen atmosphere the 16e- (PMe3)3Ru(SiMe3)H forms
a dimeric N2 adduct, [(PMe3)3Ru(SiMe3)H]2N2. Both the 16e- complex and its N2 adduct
exist in equilibrium with the 18e- silene complex, (PMe3)3Ru(CH2dSiMe2)H2. However, long
reaction times in the presence of excess borane leads to removal of another phosphine ligand
as Ph3B-PMe3 and formation of a new zwitterionic complex, (η6-PhBPh2H)Ru(PMe3)2(SiMe3)
(5), in which a molecule of borane has abstracted a ruthenium hydride ligand and also
coordinates as an η6-arene. The merits and limitations of BPh3 as a phosphine removal agent
are discussed. Compound 5 has been characterized by single-crystal X-ray analysis and
exhibits unusually long Ru-Carene bonds.
The reactivity of 18e- phosphine complexes most
and Au(PPh3)(NO3),16 Unfortunately, many of these
phosphine sponges also exhibit considerable activity in
redox and ligand substitution reactions or greatly
complicate isolation of the desired unsaturated metal
species. We recently reported in a preliminary com-
munication that treatment of (PMe3)4Ru(SiMe3)H with
BPh3 yields the 16e- (PMe3)3Ru(SiMe3)H, 2, and the
sparingly soluble BPh3-PMe3.17 In the present contri-
bution we provide more detail regarding the use of
triphenylborane as a convenient phosphine scavenger
in the generation of 2 and a ruthenium silene complex
derived from 2 and the isolation of an unusual ruthe-
nium-borane complex resulting from subsequent reac-
tion of BPh3 with the products.
commonly stems from initial reversible dissociation of
a phosphine ligand, which generates sterically and
electronically unsaturated 16e- species. The ability to
remove free phosphine from solution, hence shifting the
equilibrium in favor of the reactive unsaturated species,
is often a very desirable goal in the quest for more active
catalysts, in synthetic chemistry, and in probing details
of reaction mechanisms. Several reagents for capturing
dissociated phosphine ligands have been reported,
including MeI,1-3 B(C6F5)3,4 (9-BBN)2,5 Me3NdO,6 CS2,7
sulfur,2 CuI,8 [Cu(MeCN)4][PF6],9 Pd(PhCN)2Cl2,2,10
PdCl2(COD),10 PdCl2,11 [Pd(OCMe2)(bipy)(C6F5)][ClO4],7
(acac)Rh(C2H4)2,6,12-14 Ni(COD)2,4,6,14 [RhCl(C6H14)2]2,15
* To whom correspondence should be addressed. Fax: (215) 573-
2112. E-mail: dberry@sas.upenn.edu.
Resu lts a n d Discu ssion
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reagent. Formation of 2 and PMe3-BPh3 is relatively
fast (minutes at room temperature) and proceeds at a
rate qualitatively consistent with phosphine dissociation
from the starting complex. Complex 2 subsequently
undergoes reversible â-hydride elimination from the
silyl ligand, generating equilibrium concentrations of
the silene complex 3, (PMe3)3Ru(CH2dSiMe2)H2 (Scheme
1).17 Furthermore, in the presence of nitrogen, 2 exists
in fast equilibrium with the bridging dinitrogen com-
plex, [(PMe3)3Ru(SiMe3)H]2N2, 4, the structure of which
has been previously reported.17
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10.1021/om9908938 CCC: $19.00 © 2000 American Chemical Society
Publication on Web 07/18/2000

A Zwitterionic Ruthenium Arene Complex
Organometallics, Vol. 19, No. 17, 2000 3375
Sch em e 1
to enhancing the equilibrium concentration of active
unsaturated complexes during catalysis. In theory, one
could devise improved phosphine sponges by employing
triaryl- or trialkylboranes anchored on solid supports,
e.g., analogous to polystyrene-supported PPh3, which
would allow phosphine removal without unduly com-
plicating the separation of products from excess borane.
Syn th esis an d Ch ar acter ization of (η6-P h BP h 2H)-
Ru (P Me3)2(SiMe3). Treatment of (PMe3)4Ru(SiMe3)H
with excess BPh3 (3 equiv) initially produces a mixture
of the unsaturated 2 and the silene complex 3, but both
of these species disappear within 4 h at room temper-
ature. The principal new product is (η6-PhBPh2H)Ru-
(PMe3)2(SiMe3), 5, in which a BPh3H anion is coordi-
nated to ruthenium as an η6-arene (eq 1). Multinuclear
temperature under nitrogen does not consume all of the
starting material, but after 2 h rather produces an
equilibrium mixture containing 1 (42%), 2/4 (16%), 3
(34%), and ca. 8% total of (η6-Ph-BPh2H)Ru(PMe3)2-
(SiMe3) (vide infra) and (PMe3)3Ru(SiMe3)H3 (product
of redistribution and dehydrocoupling of silyl ligands18,19).
The equilibrium is less favorable in C6D6, leading to 53%
1, 18% 2/4, and 20% 3. It is noteworthy how little the
equilibrium is effected by the change of solvent, given
that the borane-phosphine adduct is appreciably more
soluble in C6D6 than in C6D12. Changes in the relative
amounts of 3 and 2/4 may also reflect differences in the
solubility of nitrogen gas. The effectiveness of BPh3 in
this case appears to rely more on the Lewis acidity of
the borane than on the insolubility of the adduct. One
obvious strategy to improve the stoichiometric trapping
and removal of phosphines is to employ stronger Lewis
acids such as B(C6F5)3 and B(C6H3(CF3)2)3, but these
attempts led to extensive decomposition and neither 2/4
nor 3 was observed. It is likely these Lewis acids
indiscriminately abstract hydride and/or silyl ligands,
in addition to trapping dissociated PMe3.
Alternatively, the equilibrium in Scheme 1 can be
driven by the use of excess BPh3, but this accelerates
the slow (hours) formation of (η6-Ph-BPh2H)Ru(PMe3)2-
(SiMe3), 5, at the expense of the desired 2/4 and 3. The
yield of 2/4 and 3 can be improved through the following
procedure performed in aliphatic solvents such as
pentane. An excess of BPh3 is used to shift the equilib-
rium to the right; precipitation of Ph3B-PMe3 occurs
within minutes, and most of the unreacted borane is
removed by addition of polystyrene-supported triphen-
ylphosphine.17 Both solid Ph3B-PMe3 and the polymer-
bound phosphine borane are removed by filtration. Some
borane inevitably remains in solution and slowly reacts
further to form 5 and Ph3B-PMe3, but these contami-
nants can be removed by crystallization from a large
quantity of cold pentane. Prompt recrystallization of the
concentrated mother liquors under nitrogen yields the
bridging N2 complex 4 (64%) as analytically pure
material.
NMR spectra are consistent with the structure indicated
for 5. Features in the 1H NMR spectrum that are
particularly diagnostic include three new signals be-
tween δ 5.88 and 4.49 ppm for the coordinated arene
and a 1:1:1:1 pattern at δ 4.06 ppm for the hydride
bound to four-coordinate boron. The latter is observed
at -9.73 ppm in the 11B NMR (d, J BH ) 82.5 Hz). A
single-crystal X-ray diffraction study confirmed the
proposed zwitterionic structure (vide infra).
Many examples of η6-coordination of tetraphenylbo-
rate anions have been previously reported,20-28 includ-
ing several ruthenium complexes,21-24,29 some of which
were structurally characterized.30-32 On the other hand,
the BPh3H fragment appears to be much less common,
regardless of the coordination mode. A few alkali metal
salts of [BPh3H]- have been reported, generally pre-
pared by treatment of BPh3 with the corresponding
alkali metal hydride.33,34 It is surprising that such a
weak acid as BPh3 can abstract a hydride from a weak
base, the neutral ruthenium-phosphine complex. Cer-
tainly, hydride-,35-48 alkyl-,35,45,49-52 and silyl-abstrac-
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When compared to other phosphine sponges, one can
expect BPh3 to be preferred in instances where the
products do not tolerate strong Lewis acids. Unfortu-
nately, the mild acidity of BPh3 limits its use to
complexes with extremely labile phosphine ligands or
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3376 Organometallics, Vol. 19, No. 17, 2000
Dioumaev et al.
Ta ble 1. Selected Bon d Dista n ces (Å) a n d An gles
(d eg) in (P Me3)2Ru (SiMe3)(η6-P h -BP h 2H)
Ru1-Si1 2.418(2) Ru1-P1
2.307(2) Ru1-P2 2.282(2)
Ru1-C10 2.467(6) C10-C11 1.419(9) C10-B1 1.636(9)
Ru1-C11 2.376(7) C10-C15 1.441(9) C16-B1 1.620(10)
Ru1-C12 2.264(6) C11-C12 1.415(9) C22-B1 1.614(10)
Ru1-C13 2.284(6) C12-C13 1.412(10) B1-H1 1.22(5)
Ru1-C14 2.255(6) C13-C14 1.429(10)
Ru1-C15 2.280(7) C14-C15 1.405(9)
P2-Ru1-P1
P1-Ru1-Si1
P2-Ru1-Si1
C22-B1-C16
C22-B1-C10
94.19(7)
88.66(7)
90.44(7)
113.4(6)
107.0(6)
C16-B1-C10
C22-B1-H1
C16-B1-H1
C10-B1-H1
113.7(5)
104(3)
109(3)
109(3)
Carene bond lengths (Table 1).54 There appears to be no
ambiguity regarding the location of PMe3 and SiMe3
ligands, as attempts to refine the structure with these
groups interchanged or disordered were unsuccessful.
The boron hydride was located and refined isotropically.
The B-H distance (1.22(5) Å) is unexceptional, and
there is no indication of any significant interaction with
the metal center (D(Ru‚‚‚HB) ) 3.91(5) Å.) As previously
found for other η6-borates, the phenyl is coordinated
asymmetrically, with the longest distance between Ru
and the ipso-C (2.467(6) Å), and the B(1)-C(11) vector
nearly eclipsed with that of Ru-P(1). The Ru-Cipso
distance is the longest among all η6-arene complexes of
ruthenium reported in the Cambridge Database,55
except perhaps for one structure containing an η6-arene
indole ligand. The longest Ru-C bond in the latter case
is 2.44(4) Å,56 but the high value of the standard
deviation precludes meaningful comparison to the struc-
ture of 5. Longer Ru-Carene contacts have been observed
in metal clusters.55 However, arenes in these clusters
are not coordinated η6 to any single ruthenium; hence
the Ru-C distances cannot be compared directly to 5.
The elongation of Ru-C bonds in 5 is especially surpris-
ing in light of the formal positive charge on Ru, which
is expected to result in tighter binding of electron-rich
ligands.
In conclusion, BPh3 can be utilized as a phosphine
sponge in the synthesis of coordinatively and electroni-
cally unsaturated organometallic complexes. The mild
reactivity of BPh3 offers distinct advantages over many
other phosphine-trapping reagents in some circum-
stances. However, it is also clear that BPh3 can undergo
secondary reactions with the unsaturated products,
although this can be minimized by prompt removal of
excess borane. Overall, this method of phosphine re-
moval is a potentially useful addition to the methodolo-
gies available to organometallic chemists.
F igu r e 1. ORTEP drawing of (PMe3)2Ru(SiMe3)(η6-Ph-
BPh2H), 5 (30% thermal ellipsoids). Hydrogen atoms other
than the B-H are omitted for clarity.
tion53 reactions by boranes are known, but these are
generally associated with high Lewis acidity (e.g.,
fluorinated arylboranes,35-46,49-52) or chelating effects
(e.g., 1,8-bis(dimethylboranyl)naphthalene, “hydride
sponge”47,48). Compound 5 is most likely formed by
reaction of the unsaturated 2 with BPh3, although the
order of the initial steps is not obvious. It is possible
that η2-arene coordination is assisted by concurrent
borane-hydride association and formation of an η1-
borohydride. In any case, further substitution of PMe3
by the increasing hapticity of the arene would be
assisted by the presence of additional BPh3 to scavenge
free phosphine.
The solid state structure of complex 5 (Figure 1)
adopts a three-legged piano-stool geometry with all
bonds and angles in normal ranges, except for the Ru-
(36) Yang, X.; Stern, C.; Marks, T. J . Angew. Chem., Int. Ed. Engl.
1992, 31, 1375-1377.
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3867.
Exp er im en ta l Section
All manipulations were performed in Schlenk-type glass-
ware on a dual-manifold Schlenk line or in a nitrogen-filled
Vacuum Atmospheres glovebox. NMR spectra were obtained
at 200 and 500 MHz (for 1H) on Bruker AF-200 and AM-500
(44) Dioumaev, V. K.; Harrod, J . F. Organometallics 1997, 16, 2798-
2807.
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1991, 30, 4393-4396.
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113, 3623-3625.
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(54) See the Supporting Information for the full experimental,
spectroscopic, and crystallographic details.
(55) Determined by searching the Cambridge Structural Database,
April 1999 update: Allen, F. H.; Davies, J . E.; Galloy, J . J .; J ohnson,
O.; Kennard, O.; Macrae, C. F.; Mitchell, E. M.; Mitchell, C. F.; Smith,
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A Zwitterionic Ruthenium Arene Complex
Organometallics, Vol. 19, No. 17, 2000 3377
FT NMR spectrometers, respectively. All NMR spectra were
recorded at 303 K unless stated otherwise. Chemical shifts for
1H and 13C spectra are reported relative to tetramethylsilane;
for 11B and 31P experiments external samples of BF3‚OEt2 and
85% H3PO4 were used as references. 11B, 13C, and 31P NMR
spectra were recorded with broadband 1H decoupling, unless
stated otherwise. Infrared spectra were recorded on a Perkin-
Elmer model 1430 spectrometer. Elemental analyses were
performed by Robertson Microlit Laboratory, Inc. (Madison,
NJ ).
was dissolved in C6D12 and thoroughly degassed by four
freeze-thaw cycles to furnish a dark red equilibrium mixture
of nitrogen-free (PMe3)3Ru(H)SiMe3 and (PMe3)3Ru(CH2d
SiMe2)(H)2.
(P Me3)3Ru (H)SiMe3: 1H NMR (C6D12) δ 1.42 (t, J HH ) 2.2
Hz, 18H, PMe3), 1.31 (d, J HH ) 6.0 Hz, 9H, PMe3), 0.048 (s,
9H, SiMe3), -5.94 (∼dt, 1H, J
) 34 Hz, RuH); 13C NMR
PH
(C6D12) δ 27.32 (m, mer-PMe3), 22.33 (tm, J PC ) 13.4 Hz, fac-
PMe3), 12.61 (s, SiMe3); 29Si NMR (C6D12) δ 0.62 (br s, SiMe3);
31P NMR (C6D12) δ 5.58 (d, J PP ) 22.7 Hz, 2P, fac-PMe3), -3.31
(t, J PP ) 22.9 Hz, 1P, mer-PMe3). There is no indication in the
NMR spectra (between +30 and -100 °C in C7D14) that 2
contains any other NMR active ligands, but weak coordination
of hydrocarbon solvent or a C-H bond of a phosphine or silyl
methyl group cannot be rigorously excluded.
Hydrocarbon solvents were dried over Na/K alloy-ben-
zophenone. Benzene-d6 and cyclohexane-d12 were dried over
Na/K alloy. Trimethylsilane was prepared by the reaction of
Me3SiCl and LiAlH4 in nBu2O and purified by trap-to-trap
57
58
vacuum fractionation. (PMe3)4Ru(H)SiMe3 and PMe3 were
synthesized according to the literature procedures. Triphen-
ylborane (Aldrich) was recrystallized from hexanes/toluene
before use.
(P Me3)3Ru (H)2(SiMe2dCH2): 1H NMR (C6D12) δ 1.37 (d,
J PH ) 6.7 Hz, 9H, PMe3), 1.28 (d, J PH ) 6.1 Hz, 18H, PMe3),
0.28 (s, 6H, SiMe2), -0.84 (m, 2H, RuCH2), -10.6 (m, J PH
)
45.6 and 20.5 Hz, 2H, RuH); 13C NMR (C6D12) δ 29.29 (dt,
J PC ) 21.68 and 2.22 Hz, 1PMe3), 24.36 (m, 2PMe3), 2.73 (s,
SiMe2), -20.75 (dt, J PC ) 21.7 and 6.5 Hz, CH2); 29Si NMR
(C6D12) δ -12.93 (∼dt, J PSi ) 4.4 and 2.2 Hz, SiMe2); 31P NMR
Rea ction s of 1 w ith BP h 3 in C6D6 a n d C6D12. Aliquots
of 4 mL of stock solutions of BPh3 and (PMe3)4Ru(H)SiMe3 in
pentane were added to two NMR tubes, and the solvent was
stripped in vacuo before addition of 0.57 mL of C6D6 or C6D12
.
The calculated initial concentrations of 1 and BPh3 were 0.035
M each. A substantial amount of white solid (PMe3-BPPh3)
precipitated within minutes from the cyclohexane tube. 1H
NMR spectra measured after 2 h at room temperature revealed
the following product distributions: C6D12: 42% 1, 16% 2/4,
34% 3, 6% 5, and 2% (PMe3)3Ru(H)3SiMe3. C6D6: 53% 1, 18%
2/4, 20% 3, 9% 5, and small and poorly resolved signal for
(PMe3)3Ru(H)3SiMe3.
(C6D12) δ 0.37 (d, J PP ) 22.5 Hz, 2P, PMe3), -1.41 (t, J PP
22.5 Hz, 1P, PMe3)
)
Syn th esis of (η6-P h -BP h 2H)Ru (P Me3)2(SiMe3) (5). A
toluene solution (5 mL) of BPh3 (72.6 mg, 0.3 mmol) and
(PMe3)4Ru(H)SiMe3 (47.9 mg, 0.1 mmol) was stirred at room
temperature for 4 h. The solvent was evaporated in a vacuum,
and PMe3-BPh3 was removed by sublimation at 120 °C/4 h.
The Ru-containing residue was recrystallized from THF/
toluene at -20 °C to yield 22 mg of colorless crystals (39%).
Anal. Calcd for C27H43B1P2Si1Ru1: C 56.94, H 7.6. Found: C
Syn th esis of [(P Me3)3Ru (H)SiMe3]2N2 (4). BPh3 (290 mg,
1.2 mmol) and (PMe3)4Ru(H)SiMe3 (479 mg, 1.0 mmol) were
suspended in 3 mL of cold (ca. -20 °C) pentane. A color change
from yellow to dark red and formation of a white precipitate
started within seconds. The mixture was stirred for 5 min
warming from -20 °C to room temperature and was kept at
-40 °C for 30 min. The dark red mother liquor was filtered
through a frit, and the precipitate was washed with additional
2 × 1 mL of pentane. The combined extracts were chilled (ca.
-20 °C) and stirred with 200 mg of polymer-supported PPh3
(cross-linked polystyrene beads, 3 mmol of PPh3 per 1 g of
polymer) for 10 min, decanted, treated again with 200 mg of
PPh3-polystyrene beads, and decanted again. The beads were
washed with 2 × 1 mL of cold pentane. The combined extracts
were left overnight at -40 °C to form a fine precipitate of 5
and Ph3B-PMe3. The mother liquor was decanted, reduced
in volume to 2 mL, and left to crystallize under nitrogen at
-40 °C. A color change from dark red to light yellow occurred
upon cooling. [(PMe3)3Ru(H)SiMe3]2N2 formed large colorless
plates on the walls and in the bulk of the solution. Exposure
of the crystals to solvents at room temperature leads to
formation of small amounts of the dark red 3. The crystals of
4 were mechanically separated from the small amount of
microcrystalline 1 on the bottom of the vial. Yield: 267 mg
(64%). Anal. Calcd for C24H74N2Si2P6Ru2: C 34.52, H 8.93, N
3.35. Found: 34.64, H 8.76, N 3.06.
1
57.08, H 7.83. H NMR (C6D6): δ 7.90 (d, J HH ) 7.1 Hz, 4H,
o-Ph), 7.45 (t, J HH ) 7.4 Hz, 4H, m-Ph), 7.29 (t, J HH ) 7.5 Hz,
2H, p-Ph), 5.88 (d, J HH ) 5.6 Hz, 2H, η6-o-Ph), 4.96 (t, J HH
)
5.9 Hz, 1H, η6-p-Ph), 4.49 (t, J HH ) 5.9 Hz, 2H, η6-m-Ph), 4.06
(4 lines, J BH ) 82.5 Hz, 1H, BH), 0.86 (m, 18H, PMe3), 0.07 (s,
9H, SiMe3). 13C{1H} NMR (C6D6): δ 136.0 (o-Ph), 127.3 (p-Ph),
123.8 (m-Ph), 103.9 (η6-o-Ph), 94.7 (η6-p-Ph), 90.1 (η6-m-Ph),
23.1 (dd, J PC ) 17.0 and 15.1 Hz, PMe3), 10.2 (s, SiMe3). 11B
NMR (C6D6): δ -9.73 (d, J BH ) 82.5 Hz). 11B{1H} NMR: δ
-9.73 (s). 31P{1H} NMR (C6D6): δ 4.48. IR (Nujol): ν(BH) 2270
cm-1
.
Sin gle-Cr ysta l X-r a y Diffr a ction An a lysis. Compound
(PMe3)2Ru(SiMe3)(η6-PhBPh2H), RuC27BH43SiP2, crystallizes
in the monoclinic space group P21/c (No. 14) (systematic
absences 0k0: k ) odd and h0l: l ) odd) with a ) 12.3927(2)
Å, b ) 9.7566(1) Å, c ) 24.2436(5) Å, â ) 99.541(1)°, V )
2890.76(8) Å3, Z ) 4, and dcalc ) 1.309 g/cm3. X-ray intensity
data were collected on an Rigaku R-AXIS IIc area detector
employing graphite-monochromated Mo KR radiation (λ )
0.71069 Å) at a temperature of 210 K. Indexing was performed
from a series of 1° oscillation images with exposures of 400 s
per frame. A hemisphere of data was collected using 4°
oscillation angles with exposures of 1500 s per frame and a
crystal-to-detector distance of 82 mm. Oscillation images were
processed using bioteX,59 producing a listing of unaveraged
F2 and σ(F2) values, which were then passed to the teXsan60
program package for further processing and structure solution
on a Silicon Graphics Indigo R4000 computer. A total of 18 351
reflections were measured over the ranges 5.14° e 2θ e 50.68°,
-14 e h e 14, -11 e k e 11, -29 e l e 28, yielding 5123
unique, nonzero reflections (Rint ) 0.0674). The intensity data
were corrected for Lorentz and polarization effects but not for
absorption.
[(P Me3)3(H)(SiR3)Ru ]2N2: 1H NMR (C6D12) δ 1.41 (br t,
J PH ) 2.2 Hz, 18H, PMe3), 1.32 (d, J PH ) 5.6 Hz, 9H, PMe3),
0.061 (s, 9H, SiMe3), -8.1 (dt, 1H, J
) 72 and 32 Hz, RuH);
PH
13C NMR (C6D12) δ 27.32 (m, mer-PMe3), 23.49 (virtual t,
J PC ) 12.8 Hz, fac-PMe3), 12.77 (s, SiMe3); 31P NMR (C6D12) δ
-2.82 (d, J PP ) 22.6 Hz, 2P, fac-PMe3), -11.61 (t, J PP ) 22.6
Hz, 1P, mer-PMe3); IR (powder) ν(N2) 2150, 2070 cm-1, ν(RuH)
1820 cm-1; (solution in C5H12) ν(N2) 2155 cm-1, ν(RuH) 1835
cm-1
.
Syn t h esis of (P Me3)3R u (H)SiMe3 (2) a n d (P Me3)3R u -
(CH2dSiMe2)(H)2 (3). Crystalline [(PMe3)3Ru(H)SiMe3]2N2
(59) bioteX: A Suite of Programs for the Collection, Reduction and
Interpretation of Imaging Plate Data; Molecular Structure Corpora-
tion: 1995.
(60) teXsan: Crystal Structure Analysis Package; Molecular Struc-
ture Corporation: 1985 and 1992.
(57) Procopio, L. J . Ph.D. Thesis, University of Pennsylvania, 1991.
(58) Luetkens, M. L.; Sattelberger, A. P.; Murray, H. H.; Basil, J .
D.; Fackler, J . P. Inorg. Synth. 1989, 26, 7.

3378 Organometallics, Vol. 19, No. 17, 2000
Dioumaev et al.
The structure was solved by direct methods (SIR9261).
Refinement was by full-matrix least-squares based on F2 using
SHELXL-93.62 All reflections were used during refinement
(F2’s that were experimentally negative were replaced by
F2 ) 0). The weighting scheme used was w ) 1/[σ2(Fo2) +
0.0189P2 + 14.5619P] where P ) (Fo2 + 2Fc2)/3. Non-hydrogen
atoms were refined anisotropically, and hydrogen atoms were
refined isotropically. The boron hydride was located and
refined isotropically. Refinement converged to R1 ) 0.0760 and
wR2 ) 0.1248 for 4457 reflections for which F > 4σ(F) and
R1 ) 0.0929, wR2 ) 0.1320, and GOF ) 1.229 for all 5123
unique, nonzero reflections and 461 variables.63 The maximum
∆/ σ in the final cycle of least squares was -0.034, and the
two most prominent peaks in the final difference Fourier were
+0.511 and -0.680 e/Å3.
Ack n ow led gm en t. We are grateful to the National
Science Foundation (CHE-9904798) and Tokyo Electron
Massachusetts for support of this work.
(61) SIR92: Altomare, A.; Burla, M. C.; Camalli, M.; Cascarano, M.;
Giocovazzo, C.; Guagliardi, A.; Polidoro, G. J . Appl. Crystallogr. 1994,
27, 435.
Su p p or tin g In for m a tion Ava ila ble: Details of the X-ray
structure determination (PDF). This material is available free
of charge via the Internet at http://pubs.acs.org.
(62) Sheldrick, G. M. SHELXL-93: Program for the Refinement of
Crystal Structures; Go¨ttingen University: Go¨ttingen, Germany, 1993.
(63) R1 ) ∑(||Fo| - |Fc||)/∑|Fo|. wR2 ) {∑w(Fo - Fc2)2/∑w(Fo2)2}1/2
.
2
GOF ) {∑w(Fo - Fc2)2/(n - p)}1/2 where n ) the number of reflections
and p ) the number of parameters refined.
2
OM9908938