Reactions of cis and trans beat, aryl osmium complexes (cat == l,2-O2CeH4). Bis(bcat) complexes of osmium and ruthenium and a structural comparison ofcis and trans isomers of Os(Bcat)I(CO)2(PPh3)2

Article abstract of DOI:10.1021/om0004601

Reaction of Os(Bcat)Cl(CO)(PPh3)2 (1) (HBcat = catecholborane or 1,3,2-benzodioxaborole) with o-tolyllithium gives the yellow,; five-coordinate Beat, aryl complex Os(Bcat)(o-tolyl)(CO)(PPh3)2 (2). Treatment of 2 with carbon monoxide or p-tolylisocyanide gives the corresponding saturated Beat, aryl complexes cis-Os(Bcat)(o-tolyl)(CO)2(PPh3)2 (3) and c/sOs(Bcat)(o-tolyl)(CO)(CN-p-tolyl)(PPh3)2 (4). Complexes 3 and 4 decompose in benzene solution at room temperature to give o-tolylBcat and the orthometalated triphenylphosphine complexes Os(c5lJph2)H(CO)2(PPh3) (5) and Os(C6H4PPh2)H(CO)(CN-p-tolyl)(PPh3) (as a mixture of two isomers, 6a and 6b), respectively. In the presence of B2cat2, 3 and 4 react to give the bis(Bcat) complexes Os(Bcat)2(CO)2(PPh3)2 (7) and Os(Bcat)2(CO)(CN-p-tolyl)(PPh3)2 (8). Complex 3 also reacts with HBcat to produce Os(Bcat)H(CO)2(PPh3)2 (9). The bis(Bcat) ruthenium complexes Ru(Bcat)2(CO)2(PPh3)2 (10) and Ru(Bcat)2(CO)(CN-tolyl)(PPh3)2 (11) can be prepared by treatment of Ru(CO)2(PPh3)3 or Ru(CO)(CN-p-tolyl)(PPh3)3 with B2cat2. Complex 3 reacts with C12C=CC12 or CHC13 to produce OsCl(CCl=CCl2)(CO)2(PPh3)2 (12) or OsCl2(CO)2(PPh3)2, respectively. Complex 1 when treated with CO gives cis-Os(Bcat)Cl(CO)2(PPh3)2 (13), which in turn with phenyllithium or o-tolyllithium gives ￡rans-Os(Bcat)(Ph)(CO)2(PPh3)2 (14) orrans-Os(Bcat)(o-tolylXCO)2(PPh3)2 (15). Complex 15 reacts with I2 to give a mixture of ra7i$-Os(Bcat)I(CO)2(PPh3)2 (16) and rans-Os(o-tolyl)I(CO)2(PPh3)2 (17). Complex 16 is also formed by heating cts-Os(Bcat)I(CO)2(PPh3)2 (18) in benzene. Crystal structures of complexes, 5, 8,10, 11, 12, 16, and 18 are reported.

Full text of DOI:10.1021/om0004601

4344
Organometallics 2000, 19, 4344-4355
Rea ction s of cis a n d tr a n s Bca t, Ar yl Osm iu m Com p lexes
(ca t ) 1,2-O2C6H4). Bis(Bca t) Com p lexes of Osm iu m a n d
Ru th en iu m a n d a Str u ctu r a l Com p a r ison of cis a n d
tr a n s Isom er s of Os(Bca t)I(CO)2(P P h 3)2
Clifton E. F. Rickard, Warren R. Roper,*,† Alex Williamson, and
L. J ames Wright*
Department of Chemistry, The University of Auckland, Private Bag 92019,
Auckland, New Zealand
Received May 31, 2000
Reaction of Os(Bcat)Cl(CO)(PPh3)2 (1) (HBcat ) catecholborane or 1,3,2-benzodioxaborole)
with o-tolyllithium gives the yellow, five-coordinate Bcat, aryl complex Os(Bcat)(o-tolyl)-
(CO)(PPh3)2 (2). Treatment of 2 with carbon monoxide or p-tolylisocyanide gives the
corresponding saturated Bcat, aryl complexes cis-Os(Bcat)(o-tolyl)(CO)2(PPh3)2 (3) and cis-
Os(Bcat)(o-tolyl)(CO)(CN-p-tolyl)(PPh3)2 (4). Complexes 3 and 4 decompose in benzene
solution at room temperature to give o-tolylBcat and the orthometalated triphenylphosphine
complexes Os(C6H4PPh2)H(CO)2(PPh3) (5) and Os(C6H4PPh2)H(CO)(CN-p-tolyl)(PPh3) (as a
mixture of two isomers, 6a and 6b), respectively. In the presence of B2cat2, 3 and 4 react to
give the bis(Bcat) complexes Os(Bcat)2(CO)2(PPh3)2 (7) and Os(Bcat)2(CO)(CN-p-tolyl)(PPh3)2
(8). Complex 3 also reacts with HBcat to produce Os(Bcat)H(CO)2(PPh3)2 (9). The bis(Bcat)
ruthenium complexes Ru(Bcat)2(CO)2(PPh3)2 (10) and Ru(Bcat)2(CO)(CN-p-tolyl)(PPh3)2 (11)
can be prepared by treatment of Ru(CO)2(PPh3)3 or Ru(CO)(CN-p-tolyl)(PPh3)3 with B2cat2.
Complex 3 reacts with Cl2CdCCl2 or CHCl3 to produce OsCl(CCldCCl2)(CO)2(PPh3)2 (12) or
OsCl2(CO)2(PPh3)2, respectively. Complex 1 when treated with CO gives cis-Os(Bcat)Cl(CO)2-
(PPh3)2 (13), which in turn with phenyllithium or o-tolyllithium gives trans-Os(Bcat)(Ph)-
(CO)2(PPh3)2 (14) or trans-Os(Bcat)(o-tolyl)(CO)2(PPh3)2 (15). Complex 15 reacts with I2 to
give a mixture of trans-Os(Bcat)I(CO)2(PPh3)2 (16) and trans-Os(o-tolyl)I(CO)2(PPh3)2 (17).
Complex 16 is also formed by heating cis-Os(Bcat)I(CO)2(PPh3)2 (18) in benzene. Crystal
structures of complexes, 5, 8, 10, 11, 12, 16, and 18 are reported.
In tr od u ction
comparison of cis- and trans-isomers of Os(Bcat)I(CO)2-
(PPh3)2. Some preliminary results from this work,
specifically the preparation and characterization of the
five-coordinate o-tolyl, Bcat complex, Os(Bcat)(o-tolyl)-
(CO)(PPh3)2 (2), have already been published as a
Communication.4
Compounds with transition metal-boron, 2c-2e bonds
(LnM-BR2) have been widely studied in the past decade
primarily because of the recognition that these com-
pounds are key intermediates in the metal-catalyzed
syntheses of boron-functionalized organics. Several
reviews have covered developments in this area.1-3 In
this paper we examine two features central to the role
of metal boryl complexes as catalysts in organic trans-
formations. The first of these involves the synthesis of
metal complexes containing both boryl and σ-bound
carbon ligands, LnM(BR2)R, and studies of the reductive
elimination of BR3 from these complexes. The second
involves the collection of further information on the
nature of the metal-boron bond, through a structural
Resu lts a n d Discu ssion
Red u ctive Elim in a tion of o-Tolyl-Bca t fr om cis-
o-Tolyl, Bca t Com p lexes in th e Absen ce of Oth er
Rea cta n ts. Reaction between the previously reported
coordinatively unsaturated osmium boryl complex Os-
(Bcat)Cl(CO)(PPh3)2 (1)5 and o-tolyllithium produces the
five-coordinate boryl, aryl complex Os(Bcat)(o-tolyl)-
(CO)(PPh3)2 (2).4 Treatment of 2 with either carbon
monoxide or p-tolylisocyanide produces the correspond-
ing saturated complexes cis-Os(Bcat)(o-tolyl)(CO)2-
(PPh3)2 (3)4 and cis-Os(Bcat)(o-tolyl)(CO)(CN-p-tolyl)-
(PPh3)2 (4), respectively (see Scheme 1). The spectroscopic
* Corresponding author. Phone: +64 9 373 7599 ext 8320. Fax: +64
9 373 7422.
† E-mail: w.roper@auckland.ac.nz.
(1) Wadepohl, H. Angew. Chem., Int. Ed. Engl. 1997, 36, 2441.
(2) Braunschweig, H. Angew. Chem., Int. Ed. Engl. 1998, 37, 1786.
(3) (a) Irvine, G. J .; Lesley, M. J . G.; Marder, T. B.; Norman, N. C.;
Rice, C. R.; Robins, E. G.; Roper, W. R.; Whittell, G. R.; Wright, L. J .
Chem. Rev. 1998, 98, 2685. (b) Marder, T. B.; Norman, N. C. Topics in
Catalalysis; Leitner, W., Blackmond, D. G., Ed.; Baltzer Science
Publishers: Amsterdam, 1998; Vol. 5, p 63. (c) Smith, M. R., III. Prog.
Inorg. Chem. 1999, 48, 505. (d) Chen, H.; Hartwig, J . F. Angew. Chem.,
Int. Ed. Engl. 1999, 38, 3391.
(4) Rickard, C. E. F.; Roper, W. R.; Williamson, A.; Wright, L. J .
Angew. Chem., Int. Ed. 1999, 38, 1110.
(5) (a) Irvine, G. J .; Roper, W. R.; Wright, L. J . Organometallics
1997, 16 (6), 2291. (b) Rickard, C. E. F.; Roper, W. R.; Williamson, A.;
Wright, L. J . Organometallics 1998, 17, 4869.
10.1021/om0004601 CCC: $19.00 © 2000 American Chemical Society
Publication on Web 09/14/2000

Bis(Bcat) Complexes of Os and Ru
Organometallics, Vol. 19, No. 21, 2000 4345
Sch em e 1
spectrum the hyride signals for each isomer appear as
a doublet of doublets, and these multiplicities, together
with the chemical shift positions, are indicative of the
geometries with trans phosphorus atoms, as indicated
in Scheme 1. No absolute assignment of the two isomers
(6a or 6b) has been made. The facile B-C bond
formation observed in the chemistry discussed above,
resulting from reductive elimination of cis boryl and
σ-bound carbon ligands, is a step that has been postu-
lated to occur both in metal-catalyzed hydroborations1,2
and in the borylation of arenes as described by Hartwig.7
It should be noted also that theoretical studies have
predicted very low barriers to reductive eliminations of
this type.8,9
Red u ctive Elim in a tion of o-Tolyl-Bca t fr om cis-
o-Tolyl, Bca t Com p lexes in th e P r esen ce of Com -
p ou n d s w ith B-H a n d B-B Bon d s. An important
mechanistic step often proposed in metal-catalyzed
hydroborylation or diborylation of alkenes/alkynes is the
oxidative addition of a B-H bond or B-B bond to a
reactive intermediate, thus regenerating complexes with
M-B bonds and so maintaining the catalytic cycle.
Reductive elimination of o-tolyl-Bcat from complexes 3
or 4 (giving the four-coordinate complexes “Os(CO)2-
(PPh3)2” and “Os(CO)(CN-p-tolyl)(PPh3)2”) in the pres-
ence of B2cat2 produces the bis(boryl) complexes Os-
(Bcat)2(CO)2(PPh3)2 (7) and Os(Bcat)2(CO)(CN-p-tolyl)-
(PPh3)2 (8), respectively (Scheme 2), thereby modeling
two consecutive steps for the proposed catalyzed addi-
tion of a B-B bond in diborylation reactions. Complexes
7 and 8 are the first reported bis(boryl) complexes of
osmium, and both contain cis-disposed phosphine ligands,
cis-Bcat ligands, and trans-carbonyl ligands. The struc-
ture of complex 8 was confirmed by X-ray crystal-
lography (see below).
The corresponding ruthenium bis(boryl) complexes
Ru(Bcat)2(CO)2(PPh3)2 (10) and Ru(Bcat)2(CO)(CN-p-
tolyl)(PPh3)2 (11) can be prepared by a direct oxidative
addition of B2cat2 to the zero oxidation state complexes
Ru(CO)2(PPh3)3 or Ru(CO)(CN-p-tolyl)(PPh3)3 (Scheme
3). Complexes 10 and 11 were both characterized by
X-ray crystallography (see below), and the arrange-
ments of the ligands are similar to that of the osmium
complex 8. It should be noted that the osmium bis(Bcat)
complexes 7 and 8 are not accessible through oxidative
addition of B2cat2 to the corresponding osmium zero
oxidation state complexes.
data for 4, and for all other new compounds reported in
this paper, are presented in Table 1 (IR), Table 2 (1H
NMR), Table 3 (13C NMR), and Table 4 (11B NMR). The
11B NMR data are not particularly informative because
there is only a very small variation in the 11B chemical
shifts over all the compounds measured. Apart from the
following two generalizations, these data will not be
further discussed in this paper. First, the one five-
coordinate compound measured, Os(Bcat)(o-tolyl)(CO)-
(PPh3)2 (2), has a 11B chemical shift value significantly
further upfield than the values for the six-coordinate
Bcat complexes. Second, where comparison can be made
between corresponding ruthenium and osmium com-
plexes, the ruthenium complexes show chemical shifts
at lower field values.
Complex 3 slowly decomposes in benzene solution at
room temperature to give o-tolyl-Bcat and the ortho-
metalated complex Os(C6H4PPh2)H(CO)2(PPh3) (5).6 The
nature of 5 was confirmed both by comparing the IR
spectrum with that of an authentic sample6 and by an
X-ray crystal structure determination, which is reported
in this paper. The first step in the formation of 5 is most
likely the reductive elimination of o-tolyl-Bcat, giving
the reactive, four-coordinate species “Os(CO)2(PPh3)2”,
which, in the absence of a suitable reactant, undergoes
Reductive elimination of o-tolyl-Bcat from complex 3
in the presence of HBcat cleanly produces Os(Bcat)H-
(CO)2(PPh3)2 (9) (Scheme 2), thereby modeling both the
key product-forming step and the catalyst-regenerating
step in catalytic hydroboration reactions. The triphen-
ylphosphine ligands in 9 are mutually trans, as indi-
cated by both the 1H and 13C NMR spectra, and the
presence of two carbonyl bands in the IR spectrum
indicates that the two carbonyl ligands are mutually cis.
The above observations make it clear that complex 3
can serve as a convenient precursor for “Os(CO)2(PPh3)2”
and treatment of 3 with Cl2CdCCl2 or CHCl3 gives
orthometalation to form Os(C6H4PPh2)H(CO)2(PPh3)
(see Scheme 1). The reductive elimination of o-tolyl-Bcat
1
in CDCl3 was monitored by H NMR spectroscopy and
found to be approximately half completed, at 25 °C, after
100 min. Under these conditions the osmium complex
formed is OsCl2(CO)2(PPh3)2, which results from reac-
tion of “Os(CO)2(PPh3)2” with the solvent (see below).
Complex 4 also readily eliminates o-tolyl-Bcat to give
the orthometalated complex Os(C6H4PPh2)H(CO)(CN-
p-tolyl)(PPh3) (6), as a mixture of two isomers (6a and
6b). These have not been separated, but both have the
two phosphorus atoms arranged mutually trans, as
shown by the large J PP values observed in the 31P NMR
(7) Waltz, K. M.; Muhoro, C. N.; Hartwig, J . F. Organometallics
1999, 18, 3383.
(8) (a) Musaev, D. G.; Mebel, A. M.; Morokuma K. J . Am. Chem.
Soc. 1994, 116, 10693. (b) Dorigo, A. E.; von R. Schleyer, P. Angew.
Chem., Int. Ed. Engl. 1995, 34, 115.
1
spectrum (see Experimental Section). In the H NMR
(6) Clark, G. R.; Headford, C. E. L.; Marsden, K.; Roper, W. R. J .
Organomet. Chem. 1982, 231, 335.
(9) Sakaki, S.; Kai, S.; Sugimoto, M. Organometallics 1999, 18, 4825.

4346 Organometallics, Vol. 19, No. 21, 2000
Rickard et al.
a
Ta ble 1. In fr a r ed Da ta (cm -1
)
for Ru th en iu m a n d Osm iu m Bor yl Com p lexes a n d Der ived Com p lexes
complex
ν(CdO)
1941s
ν(CdN)
other bandsb
cis-Os(Bcat)(o-tolyl)(CO)(CN-p-tolyl)(PPh3)2 (4)
2097s
1237m, 1117m, 1081s,
1005w, 813m
1884mc
2009vs, 1956vs
1959m, br,
Os(C6H4PPh2)H(CO)2(PPh3) (5)
2089m,br
2141m
Os(C6H4PPh2)H(CO)(CN-p-tolyl)(PPh3) (6)
1935m, br,
1913m, bre
1964vs
Os(Bcat)2(CO)(CN-p-tolyl)(PPh3)2 (8)
Os(Bcat)H(CO)2(PPh3)2 (9)
1236s, 1128m, 1102s,
1072s, 1011m, 811w
1895s,c 1235s, 1135m,
1015m, 813w
1971s,
2009s
Ru(Bcat)2(CO)2(PPh3)2 (10)
1975vs,
2057w
1236s, 1137m, 1112s,
1104m, 1072s, 1027w,
811w
Ru(Bcat)2(CO)(CN-p-tolyl)(PPh3)2 (11)
Os(CCldCCl2)Cl(CO)2(PPh3)2 (12)
cis-Os(Bcat)Cl(CO)2(PPh3)2 (13)
1974vs
2141s
1235s, 1119m, 1063s,
1012m, 809m
2027vs,
1952vs
2025m,
1965m,
1941vsd
1948vs,
1920w
1970vs,
2064w
2020s,
1231m, 1149w, 1109m,
1031w, 813w
trans-Os(Bcat)(Ph)(CO)2(PPh3)2 (14)
trans-Os(Bcat)I(CO)2(PPh3)2 (16)
cis-Os(Bcat)I(CO)2(PPh3)2 (18)
1234m, 1121m, 1083s,
1104m, 809w
1235m, 1135w, 1092s,
1028w, 810w
1237s, 1149m, 1116s,
1099s, 1029m, 814w
1958vs
a
b
d
Spectra recorded as Nujol mulls between KBr plates. Bands associated with boryl ligand unless denoted otherwise. c ν(OsH). Solid-
state splitting. e Distinction between ν(CO) and ν(OsH) has not been made.
OsCl(CCldCCl2)(CO)2(PPh3)2 (12) and OsCl2(CO)2(PPh3)2,
respectively (Scheme 4). An X-ray crystallographic
structure determination of 12 (see below) confirmed the
presence of a metal-bound trichlorovinyl ligand cis to a
chloride ligand, with mutually trans triphenylphosphine
ligands and mutually cis carbonyl ligands.
elimination of aryl-Bcat at room temperature or even
when heated under reflux in benzene for several hours.
However, under the same conditions but with addition
of irradiation with a 1000 W tungsten-halogen lamp,
the aryl-Bcat molecule is eliminated and the orthometa-
lated complex Os(C6H4PPh2)H(CO)2(PPh3) is formed.
Presumably under these conditions the trans-isomer
must first rearrange to form the cis-isomer, which then
rapidly undergoes elimination and orthometalation.
Reaction of 15 with I2 gives an approximately 1:1
mixture of two osmium complexes (Scheme 5), which
can be separated easily by column chromatography. The
two products, trans-Os(Bcat)I(CO)2(PPh3)2 (16) and
trans-Os(o-tolyl)I(CO)2(PPh3)2 (17), are formed by cleav-
age of the Os-C(o-tolyl) and Os-B bonds, respectively.
The trans arrangement of the boryl and iodide ligands
in 16 was confirmed by X-ray crystallography (see
below). Since the corresponding cis-isomer was easily
accessible, the opportunity was taken to examine the
structural parameters, and hence the bonding proper-
ties, of the Bcat ligand in these two isomeric complexes.
The cis-isomer was made by treating Os(Ph)I(CO)-
(PPh3)2 with HBcat to afford Os(Bcat)I(CO)(PPh3)2,
which in turn reacts with carbon monoxide to form cis-
Os(Bcat)I(CO)2(PPh3)2 (18) (Scheme 6). The structure
of 18 was determined by X-ray diffraction analysis. The
trans-isomer 16 is more thermodynamically stable than
the cis-isomer 18, since upon heating under reflux in
benzene solution for 2 h, 18 is completely converted to
the trans-isomer 16. For octahedral dicarbonyl com-
plexes it is usual to find that the cis-dicarbonyl isomer
is thermodynamically more stable than the correspond-
ing trans-isomer. That this is not so in the above
example is once again testimony to the fact that a trans-
disposition of a Bcat ligand and a π-accepting CO ligand
is an unfavorable bonding combination (see later discus-
sion of the structures of 16 and 18).
Syn th esis a n d Rea ction s of tr a n s-Os(Bca t)(P h )-
(CO)2(P P h 3)2 (14) a n d tr a n s-Os(Bca t)(o-tolyl)(CO)2-
(P P h 3)2 (15). Carbonylation of the five-coordinate com-
plex 1 produces the expected saturated complex cis-
Os(Bcat)Cl(CO)2(PPh3)2 (13), in which the carbonyl
ligands are mutually cis and the triphenylphosphine
ligands are mutually trans. Treatment of 13 with
phenyllithium or o-tolyllithium produces the trans aryl,
boryl complexes trans-Os(Bcat)(Ph)(CO)2(PPh3)2 (14) or
trans-Os(Bcat)(o-tolyl)(CO)2(PPh3)2 (15), respectively
(see Scheme 5). We have proposed4 that this reaction
proceeds initially by nucleophilic attack by the aryl
anion at the carbonyl ligand trans to the Bcat ligand.
This is followed by loss of the chloride ligand to form a
neutral complex in which the acyl ligand may adopt
either an η1- or an η2-bonding mode. This neutral
intermediate then undergoes reverse migratory inser-
tion, placing the aryl ligand trans to the boryl ligand.
The carbonyl ligand trans to the Bcat ligand in 13 is
activated toward nucleophilic attack by being located
trans to the boryl ligand. Other related complexes, viz.,
trans-Ru(Bcat)Cl(CO)2(PPh3)2, trans-Os(Bcat)I(CO)2-
(PPh3)2, Os(Bcat)Cl(CO)(CN-p-tolyl)(PPh3)2, and Os(Si-
{OEt}3)Cl(CO)2(PPh3)2, which contain a carbonyl ligand
located trans to one of the following ligands, CO, isocy-
anide, triethoxysilyl, do not show a similar reaction with
aryllithium reagents. This emphasizes the specific acti-
vating effect of the Bcat ligand. The X-ray crystal struc-
ture of 154 confirms that it is a geometric isomer of 3.
Because of the trans disposition of the boryl and aryl
groups, complexes 14 and 15 do not undergo reductive

Bis(Bcat) Complexes of Os and Ru
Organometallics, Vol. 19, No. 21, 2000 4347
Ta ble 2. 1H NMR Da ta a for Ru th en iu m a n d Osm iu m Bor yl Com p lexes a n d Der ived Com p lexes
complex
1H, δ (ppm)
cis-Os(Bcat)(o-tolyl)(CO)(CN-p-tolyl)(PPh3)2 (4)b
1.89 (s, 3H, C6H4Me), 2.33 (s, 3H,
CNC6H4Me), 6.16-6.63 (m, 5H, C6H4Me,
CNC6H4Me), 6.76 (m, 2H, Bcat), 6.82 (m,
2H, Bcat), 7.03-7.39 (m, 33H, PPh3, C6H4Me
and CNC6H4Me)
2
2
- 4.75 (dd, J HP ) 21.4 Hz, J HP ) 18.6 Hz,
1H, OsH), 6.63 (m, 1H, OsC6H4), 6.87-7.04
(m, 3H, OsC6H4), 7.35-7.43 (m, 15H, PPh3
and PPh2), 7.57-7.66 (m, 8H, PPh3 and
PPh2), 7.88-7.94 (m, 2H, PPh2)
Os(C6H4PPh2)H(CO)2(PPh3) (5)
2
2
Isomer 1: - 5.59 (dd, J HP ) 20.2 Hz, J HP
17.4 Hz, 1H, OsH), 2.22 (s, 3H,
)
Os(C6H4PPh2)H(CO)(CN-p-tolyl)(PPh3) (6)
3
CNC6H4CH3), 5.99 (d, J HH ) 8.1 Hz, 2H,
CNC6H4CH3), 6.67 (m, 1H, OsC6H4) 6.82 (d,
J ) 8.1 Hz, 2H, CNC6H4CH3)
2
2
Isomer 2: - 4.58 (dd, J HP ) 20.8 Hz, J HP
)
19.2 Hz, 1H, OsH), 2.29 (s, 3H,
3
CNC6H4CH3), 6.62 (d, J HH ) 8.3 Hz, 2H,
CNC6H4CH3), 6.74 (m, 1H, OsC6H4)
Overlapping resonances of both isomers:
6.85-7.24 (m, OsC6H4 and CNC6H4CH3),
7.29-7.42, 7.63-7.74, 7.98-7.80 (m, PPh3
and PPh2)
Os(Bcat)2(CO)(CN-p-tolyl)(PPh3)2 (8)
2.38 (s, 3H, CNC6H4Me), 6.65 (m, 4H, Bcat),
6.78 (m, 4H, Bcat), 6.97 (d, J HH ) 8.2 Hz,
3
CNC6H4Me), 7.03 (m, 12H, PPh3), 7.11 (m,
8H, PPh3 and CNC6H4Me), 7.31-7.35 (m,
12H, PPh3)
2
Os(Bcat)H(CO)2(PPh3)2 (9)
-7.18 (t, J HP ) 21.5 Hz, 1H, OsH), 6.61 (m,
4H, Bcat), 7.20-7.23 (m, 18H, PPh3),
7.50-7.56 (m, 12H, PPh3)
6.70 (m, 4H, Bcat), 6.82, (m, 4H, Bcat), 7.09
(m, 12H, PPh3), 7.17 (m, 6H, PPh3),
7.27-7.33 (m, 12H, PPh3)
2.38 (s, 3H, CNC6H4Me), 6.65 (m, 4H, Bcat),
6.76 (m, 4H, Bcat), 6.97-7.03 (m, 14H, PPh3
and CNC6H4Me), 7.09-7.14 (m, 8H,
CNC6H4Me and PPh3), 7.32-7.36 (m, 12H,
PPh3)
Ru(Bcat)2(CO)2(PPh3)2 (10)
Ru(Bcat)2(CO)(CN-p-tolyl)(PPh3)2 (11)
Os(CCldCCl2)Cl(CO)2(PPh3)2 (12)
cis-Os(Bcat)Cl(CO)2(PPh3)2 (13)
trans-Os(Bcat)(Ph)(CO)2(PPh3)2 (14)
7.36-7.44 (m, 18H, PPh3), 7.57-7.65 (m,
12H, PPh3)
6.74-6.82 (m, 4H, Bcat), 7.23-7.26 (m, 18H,
PPh3), 7.61-7.66 (m, 12H, PPh3)
6.62 (m, 2H, Ph), 6.69 (m, 2H, Bcat), 6.75 (m,
3H, Bcat and Ph), 7.09-7.17 (m, 20H, PPh3
and Ph), 7.27-7.32 (m, 12H, PPh3)
6.61 (m, 2H, Bcat), 6.71 (m, 2H, Bcat),
7.17-7.24 (m, 18H, PPh3), 7.61-7.67 (m,
12H, PPh3)
trans-Os(Bcat)I(CO)2(PPh3)2 (16)
cis-Os(Bcat)I(CO)2(PPh3)2 (18)
o-tolyl-Bcat
6.76-6.82 (m, 4H, Bcat), 7.22-7.24 (m, 18H,
PPh3), 7.62-7.67 (m, 12H, PPh3)
2.74 (s, 3H, C6H4CH3), 7.13 (m, 2H, Bcat),
7.28-7.34 (m, 4H, C6H4CH3 and Bcat), 7.45
(apparent td, J ) 7.7 Hz, J ) 1.3 Hz, 1H,
C6H4CH3), 8.11 (apparent dd, J ) 7.7 Hz, J )
1.3 Hz, 1H, C6H4CH3)
a
Spectra recorded in CDCl3 at 25 °C unless indicated otherwise. Chemical shifts are referenced to Me4Si (δ ) 0.00). Splitting patterns
b
and line shapes are indicated thus: s ) singlet, d ) doublet, t ) triplet, q ) quartet, br ) broad. Recorded at -40 °C.
Cr ysta l Str u ctu r e Deter m in a tion s. The crystal
structures of complexes 3 and 15 have been reported
previously.4 In this paper we report crystal structure
determinations for complexes 5, 8, 10, 11, 12, 16, and
18. The crystal and refinement data are presented in
Table 5, and selected bond distances and angles for
these complexes are presented in Tables 6-12.
was located at an Os-H distance of 1.68(3) Å. Other
features of the structure are unremarkable and similar
to those of other ortho-metalated triphenylphosphine
complexes.10
Str u ctu r es of th e Bis(Bca t) Com p lexes 8, 10, a n d
11. The molecular structures of 8, 10, and 11 are shown
in Figures 2-4. All three compounds have essentially
(10) (a) Bennett, M. A.; Berry, D. E.; Bhargava, S. K.; Ditzel, E. J .;
Robertson, G. B.; Willis, A. C. J . Chem. Soc., Chem. Commun. 1987,
1613. (b) Bruce, M. I.; Cifuentes, M. P.; Humphrey, M. G.; Poczman,
E.; Snow, M. R.; Tiekink, E. R. T. J . Organomet. Chem. 1988, 338,
237. (c) Fryzuk, M. D.; Montgomery, C. D.; Rettig, S. J . Organometallics
1991, 10, 467. (d) Chappell, S. D.; Engelhardt, L. M.; White, A. H.;
Raston, C. L. J . Organomet. Chem. 1993, 462, 295.
Str u ctu r e of Os(C6H4P P h 2)H(CO)2(P P h 3) (5). The
molecular structure of 5 is shown in Figure 1. The
geometry about osmium is approximately octahedral,
with the two phosphorus atoms mutually trans and the
two carbonyl ligands mutually cis. The hydride ligand

4348 Organometallics, Vol. 19, No. 21, 2000
Rickard et al.
Ta ble 3. 13C NMR Da ta a for Ru th en iu m a n d Osm iu m Bor yl Com p lexes a n d Der ived Com p lexes
complex
13C, δ (ppm)
cis-Os(Bcat)(o-tolyl)(CO)(CN-p-tolyl)(PPh3)2 (4)d
21.36 (CNC6H4Me), 32.19 (C6H4Me),
110.40 (Bcat), 119.35 (Bcat), 121.73
(C6H4Me), 121.97 (C6H4Me), 124.74
(CNC6H4Me), 126.28 (C6H4Me), 127.08
2,4
(t′,
J
) 9 Hz, o-PPh3), 128.98 (p-PPh3),
CP
3,5
129.71 (CNC6H4Me), 133.87 (t′,
10 Hz, m-PPh3), 134.73 (t′,
J
)
CP
1,3
J
) 50 Hz,
CP
i-PPh3), 138.05 (CNC6H4Me), 147.79 (t,
2J CP ) 11 Hz, i-C6H4Me), 148.24
(C6H4Me), 150.06 (C6H4Me), 150.25
(Bcat), 186.22 (CO)b,c
124.44-139.34 (complex overlapping
Os(C6H4PPh2)H(CO)2(PPh3) (5)
2
2
resonances), 154.46 (dd, J CP ) 57 Hz, J CP
2
) 3 Hz, Os-i-C6H4), 183.90 (dd, J CP ) 7
2
Hz, J CP ) 2 Hz, CO), 185.35 (apparent t,
2,2
J
) 6 Hz, CO)
CP
Os(Bcat)2(CO)(CN-p-tolyl)(PPh3)2 (8)
21.37 (CNC6H4Me), 110.36 (Bcat), 119.52
(Bcat), 125.67 (CNC6H4Me), 127.27
2,4
(CNC6H4Me), 127.54 (t′,
J
) 10 Hz,
CP
o-PPh3), 128.86 (p-PPh3), 129.59
3,5
(CNC6H4Me), 133.40 (t′,
J
) 12 Hz,
CP
m-PPh3), 137.52 (m, i-PPh3), 138.03
(CNC6H4Me), 150.61 (Bcat), 153.46 (t,
2J CP ) 10.5 Hz, CNC6H4Me), 192.16 (t,
2J CP ) 7.5 Hz, CO)
Os(Bcat)H(CO)2(PPh3)2 (9)
110.32 (Bcat), 119.60 (Bcat), 127.76 (t′,
2,4
J
) 10 Hz, o-PPh3), 129.62 (p-PPh3),
CP
3,5
133.60 (t′,
J
) 11 Hz, m-PPh3), 136.24
CP
1,3
(t′,
J
) 53 Hz, i-PPh3), 150.13 (Bcat),
CP
2
186.24 (t, J CP ) 6 Hz, CO)e
Ru(Bcat)2(CO)2(PPh3)2 (10)
110.74 (Bcat), 120.10 (Bcat), 127.93 (t′,
2,4
J
) 8 Hz, o-PPh3), 129.24 (p-PPh3),
CP
3,5
133.16 (t′,
J
) 12 Hz, m-PPh3), 136.47
CP
2
(m, i-PPh3), 149.72 (Bcat), 204.21 (t, J CP
9.5 Hz, CO)
)
Ru(Bcat)2(CO)(CN-p-tolyl)(PPh3)2 (11)
21.36 (CNC6H4Me), 110.36 (Bcat), 119.55
(Bcat), 125.52 (CNC6H4Me), 127.01
2,4
(CNC6H4Me), 127.62 (t′,
J
) 7 Hz,
CP
o-PPh3), 128.63 (p-PPh3), 129.61
3,5
(CNC6H4Me), 133.36 (t′,
J
) 12 Hz,
CP
m-PPh3), 137.65 (m, i-PPh3), 138.14
(CNC6H4Me), 150.17 (Bcat), 168.30
2
(CNC6H4Me),c 207.10 (t, J CP ) 10 Hz,
CO)
3
Os(CCldCCl2)Cl(CO)2(PPh3)2 (12)
118.91 (t, J CP ) 4 Hz, CCl2), 127.96
(t′, 2,4J CP ) 10 Hz, o-PPh3), 130.49 (t′,
1,3
J
) 52 Hz, i-PPh3), 130.69 (p-PPh3),
CP
3,5
134.39 (t′,
J
) 10 Hz, m-PPh3), 143.10
CP
2
(t, J CP ) 12.5 Hz, CCldCCl2), 176.06 (t,
2J CP ) 8.5 Hz, CO), 179.83 (t, J CP ) 7.5
2
Hz, CO)
cis-Os(Bcat)Cl(CO)2(PPh3)2 (13)
110.93 (Bcat), 120.26 (Bcat), 127.91 (t′,
2,4
J
) 10 Hz, o-PPh3), 130.05 (p-PPh3),
CP
1,3
133.32 (t′,
(t′,
J
) 53 Hz, i-PPh3), 133.80
CP
3,5
J
) 11 Hz, m-PPh3), 149.88 (Bcat),
CP
2
177.87 (t, J CP ) 7.5 Hz, CO), 182.05 (t,
2J CP ) 9 Hz, CO)
trans-Os(Bcat)(Ph)(CO)2(PPh3)2 (14)
110.09 (Bcat), 119.67 (Bcat), 121.45 (Ph),
2,4
127.12 (Ph), 127.49 (t′,
o-PPh3), 129.47 (p-PPh3), 133.66 (t′,
) 10 Hz, m-PPh3), 134.75 (t′,
Hz, i-PPh3), 141.25 (t, J CP ) 9 Hz, i-Ph),
J
) 9 Hz,
CP
3,5
J
CP
) 52
1,3
J
CP
2
2
147.16 (Ph), 150.33 (Bcat), 190.30 (t, J CP
) 11 Hz, CO)
trans-Os(Bcat)I(CO)2(PPh3)2 (16)
cis-Os(Bcat)I(CO)2(PPh3)2 (18)
110.57 (Bcat), 120.11 (Bcat), 127.92 (t′,
2,4
J
) 10 Hz, o-PPh3), 130.11 (p-PPh3),
CP
1,3
133.71 (t′,
(t′,
J
) 54 Hz, i-PPh3), 133.99
CP
3,5
J
) 10 Hz, m-PPh3), 149.95 (Bcat),
CP
2
185.14 (t, J CP ) 10 Hz, CO)
111.02 (Bcat), 120.32 (Bcat), 127.74 (t′,
2,4
J
) 10 Hz, o-PPh3), 130.02 (p-PPh3),
CP
1,3
134.03 (t′,
(t′,
J
) 54 Hz, i-PPh3), 134.07
CP
3,5
J
) 10 Hz, m-PPh3), 150.19 (Bcat),
CP
2 2
175.12 (t, J CP ) 7 Hz, CO), 179.45 (t, J CP
) 9 Hz, CO)
o-tolyl-Bcat
22.44 (C6H4CH3), 112.54 (Bcat), 122.70
(Bcat), 125.21 (C6H4CH3), 130.32
(C6H4CH3), 132.09 (C6H4CH3), 136.59
(C6H4CH3), 145.57 (C6H4CH3),148.43
(Bcat)f
a
Spectra recorded in CDCl3 at 25 °C unless indicated otherwise. Chemical shifts are referenced to CDCl3 (δ ) 77.00). t′ denotes signal
has apparent triplet multiplicity, m,nJ CP is the sum of the two coupling constants mJ CP and J CP as explained in ref 11. b CN-p-tolyl resonance
n
obscured. c Coupling to P not observed. Recorded at -40 °C. e Second carbonyl not observed. f ipso-C6H4CH3 not observed.
d

Bis(Bcat) Complexes of Os and Ru
Organometallics, Vol. 19, No. 21, 2000 4349
Ta ble 4. 11B NMR Da ta a for Selected Bor yl
Com p lexes
Sch em e 5
complex
11B, δ (ppm)
Os(Bcat)(o-tolyl)(CO)(PPh3)2 (2)
cis-Os(Bcat)(o-tolyl)(CO)2(PPh3)2 (3)
cis-Os(Bcat)(o-tolyl)(CO)(CN-p-tolyl)(PPh3)2 (4)
Os(Bcat)2(CO)2(PPh3)2 (7)
Os(Bcat)2(CO)(p-CNC6H4Me)(PPh3)2 (8)
Os(Bcat)H(CO)2(PPh3)2 (9)
26.5
46.0
47.2
43.9
45.6
45.2
48.2
50.0
43.3
43.3
36.6b
44.3
Ru(Bcat)2(CO)2(PPh3)2 (10)
Ru(Bcat)2(CO)(CN-p-tolyl)(PPh3)2 (11)
trans-Os(Bcat)(Ph)(CO)2(PPh3)2 (14)
trans-Os(Bcat)(o-tolyl)(CO)2(PPh3)2 (15)
trans-Os(Bcat)I(CO)2(PPh3)2 (16)
cis-Os(Bcat)I(CO)2(PPh3)2 (18)
a
Spectra recorded in CDCl3 at 25 °C unless indicated otherwise.
b
Chemical shifts are referenced to BF3‚OEt2 (δ ) 0.00). Spectrum
recorded in CDCl3/CH2Cl2.
Sch em e 2
Sch em e 6
carbonyl and isocyanide) ligands occupying axial sites.
All metal-phosphorus distances are closely similar as
are the P(1)-M-P(2) angles, which range between
103.75(4)° and 109.51(3)°. The M-B bond distances are
almost constant over the three compounds (2.086(3)-
2.104(6) Å). An interesting feature is that in each case
the Bcat ligands are arranged face-to-face with acute
B(1)-M-B(2) angles of 77.0(2)°, 75.43(14)°, and 75.57-
(12)° for 8, 10, and 11, respectively. Similar small angles
have been noted for other bis(boryl) metal complexes.2,3
As would be expected, the cis triphenylphosphine ligands
have P(1)-M-P(2) bond angles greater than 90° and
the two carbonyl (or carbonyl and isocyanide) ligands
are very close to linear.
Sch em e 3
Sch em e 4
St r u ct u r e of Os(CCldCCl2)Cl(CO)(P P h 3)2 (12).
The molecular structure of 12 is shown in Figure 5. The
geometry about osmium is approximately octahedral
with the two phosphorus atoms mutually trans and the
two carbonyl ligands mutually cis. The C(3)-C(4)
distance in the trichlorovinyl ligand is 1.293(9) Å,
appropriate for a double bond. There is significant
variation in the C-Cl distances, the longest being that
between the osmium-bound carbon and chloride, i.e.,
C(4)-Cl(4), which is 1.847(7) Å. The angle Os-C(4)-
C(3) is opened considerably from the idealized 120° to
134.2(5)°, while both the angles Os-C(4)-Cl(4) (114.7-
(3)°) and C(3)-C(4)-Cl(4) (110.9(5)°) are reduced.
Str u ctu r es of th e Os(Bca t)I(CO)2(P P h 3)2 Isom er s
16 a n d 18. The molecular structures of trans-Os(Bcat)I-
(CO)2(PPh3)2 (16) and cis-Os(Bcat)I(CO)2(PPh3)2 (18) are
shown in Figures 6 and 7, respectively. In both cases
the geometry about osmium is approximately octahe-
the same arrangement of ligands about the metal
centers. The two mutually cis triphenylphosphine ligands
and the two mutually cis Bcat ligands are approximately
coplanar, with the accompanying two carbonyl (or

4350 Organometallics, Vol. 19, No. 21, 2000
Ta ble 5. Cr ysta l a n d Refin em en t Da ta for 5, 8, 10, 11, 12, 16, a n d 18
Rickard et al.
5
8
10
11
formula
molecular weight
temp, K
C
38H30O2OsP2
C57H45B2O5OsP2
1097.7
203
C50H38B2O6P2Ru. C7H8
1011.57
203
C57H45B2O5P2Ru
1008.57
203
770.76
203
wavelength, Å
cryst syst
space group
a, Å
b, Å
c, Å
0.71073
monoclinic
P21/n
16.35510(10)
10.99250(10)
17.71080(10)
97.350(1)
3157.92(4)
4
1.621
1520
4.172
0.40 × 0.37 × 0.26
1.6-27.1
-20 e h e 20,
0 e k e 14,
0 e l e 22
18 839
0.71073
monoclinic
P21/c
10.3198(2)
26.6368(4)
18.3147(1)
102.171(1)
4872.9(1)
4
1.496
2200
2.733
0.35 × 0.11 × 0.11
1.4-27.5
-13 e h e 13,
0 e k e 34,
0 e l e 23
28 732
0.71073
monoclinic
P21/c
13.7644(3)
19.0556(4)
18.7402(1)
94.342(1)
4901.2(9)
4
0.71073
monoclinic
P21/c
10.3153(3)
26.6868(5)
18.1026(5)
102.177(1)
4871.2(3)
4
1.375
2071
0.438
0.36 × 0.10 × 0.08
1.4-28.2
-12 e h e 12,
0 e k e 34,
0 e l e 22
29 954
â, deg
V, Å3
Z
d(calc), g cm-3
F(000)
1.371
2080
0.437
µ, mm-1
cryst size, mm
2θ (min - max), deg
h,k,l range
0.57 × 0.47 × 0.11
1.5-28.3
-18 e h e 17,
0 e k e 24,
0 e l e 23
28 827
no. of reflns collected
no. of independent reflns
A (min, max)
function minimized
no. of data/restraints/params
goodness of fit on F2
R (obsd data)a
6764, Rint 0.0189
0.2861, 0.4101
10 623, Rint 0.0526
0.448, 0.753
10 975, Rint 0.0326
0.789, 0.953
10 908, Rint 0.0405
0.858, 0.966
2
2
2
2
2
2
2
2
2
2
2 2
∑w(Fo - Fc
)
∑w(Fo - Fc
)
∑w(Fo - Fc
)
∑w(Fo - Fc )
6764/0/391
1.060
10 623/0/614
1.096
10 975/0/578
0.949
10 908/0/614
1.072
R1 ) 0.0222
wR2 ) 0.0545
R1 ) 0.0251
wR2 ) 0.0565
0.0230, 5.2423
+1.76, -0.91
R1 ) 0.0481
wR2 ) 0.0698
R1 ) 0.0869
wR2 ) 0.0836
0.0000, 11.605
+0.99, -0.99
R1 ) 0.0400
wR2 ) 0.0926
R1 ) 0.0693
wR2 ) 0.01104
0.0538, 4.893
+0.59, -0.56
R1 ) 0.0416
wR2 ) 0.0678
R1 ) 0.0737
wR2 ) 0.0788
0.0111, 3.860
+0.37, -0.43
R (all data)
least-squares weights a, b
diff map (min, max), e Å-3
12
40H30Cl4O2OsP2
936.58
203
16
18
formula
molecular weight
temp, K
C
C44H34BIO4OsP2.CH2Cl2
1101.49
C44H34BIO4OsP2‚CH2Cl2
1101.49
203
203
wavelength, Å
cryst syst
space group
a, Å
b, Å
c, Å
0.71073
orthorhombic
Pbca
12.0712(1)
17.2622(1)
34.6301(1)
0.71073
monoclinic
P21/c
17.0528(2)
13.2932(1)
19.4297(2)
109.013(1)
4274.05(7)
4
0.71073
orthorhombic
P212121
11.2964(1)
11.9060(1)
31.3608(3)
â, deg
V, Å3
7216.06(8)
8
1.724
3680
3.955
4217.97(5)
14
1.735
2144
4.000
Z
d(calc) g cm-3
F(000)
1.712
2144
3.948
µ, mm-1
cryst size, mm
2θ (min, max) deg.
h,k,l range
0.42 × 0.21 × 0.13
0.38 × 0.30 × 0.30
0.55 × 0.36 × 0.27
2.1, 27.2
1.9, 28.3
1.3, 26.5
0 e h e 15,
0 e k e 21,
0 e l e 44
43 497
-23 e h e 21,
0 e k e 17,
0 e l e 25
25 972
-14 e h e 14,
0 e k e 24,
0 e l e 39
23 823
no. of reflns collected
no. of ind reflns
A (min, max)
function minimized
no. of data/restraints/params
goodness of fit on F2
R (obsd data)
7861, Rint 0.0255
0.287, 0.627
9540, Rint 0.0152
0.315, 0.383
8615, Rint 0.0394
0.217, 0.411
2
2
2
2
2
2
2
2 2
∑w(Fo - Fc
)
∑w(Fo - Fc
)
∑w(Fo - Fc
)
7861/0/442
1.393
9540/0/500
1.104
8615/0/506
1.015
R1 ) 0.0434
R1 ) 0.0207
R1 ) 0.0249
wR2 ) 0.0547
R1 ) 0.0276
wR2 ) 0.0560
0.0000, 0.1000
+0.89, -0.77
wR2 ) 0.0902
R1 ) 0.0468
wR2 ) 0.0914
0.0000, 49.27
+1.47, -2.15
wR2 ) 0.0540
R1 ) 0.0228
wR2 ) 0.0553
0.0235, 6.110
+1.18, -0.83
R (all data)
least-squares weights a, b
diff map (min, max), e Å-3
R ) ∑||Fo| - |Fc||/∑|Fo|. wR2 ) {∑[w(Fo - Fc2)2]/∑[w(Fo2)2]}1/2. Weight ) 1.0/[σ2(Fo2) + aP2 + bP]; P ) (Fo +2Fc2)/3.
a
2
2
dral, with the two phosphorus atoms mutually trans and
the two carbonyl ligands either mutually trans (16) or
cis (18). In complex 16 the boryl ligand is located trans
to the iodide ligand and a strong trans influence is
apparent from a long Os-I bond distance of 2.8346(2)
Å. The carbonyl ligands are displaced toward the Bcat
ligand (angle C(1)-Os-B, 84.85(12)° and angle C(2)-
Os-B, 82.60(12)°), and the orientation of the plane of
the Bcat ligand is tilted by 11.83(13)° with respect to
the plane of best fit through the Os, B, C(1), C(2), and
I atoms. The average Os-CO bond distance is 1.941(3)
Å and the Os-B bond distance is 2.090(3) Å, much

Bis(Bcat) Complexes of Os and Ru
Organometallics, Vol. 19, No. 21, 2000 4351
Ta ble 6. Selected Bon d Dista n ces (Å) a n d An gles
(d eg) for Com p lex 5
Ta ble 9. Selected Bon d Dista n ces (Å) a n d An gles
(d eg) for Com p lex 11
Interatomic Distances
Interatomic Distances
Os-H(1)
Os-C(2)
Os-C(1)
Os-C(12)
Os-P(1)
Os-P(2)
O(1)-C(1)
1.68(3)
O(2)-C(2)
1.153(4)
1.396(4)
1.420(4)
1.405(4)
1.397(4)
1.387(5)
1.388(5)
Ru-B(1)
Ru-B(2)
Ru-C(1)
Ru-C(2)
Ru-P(1)
Ru-P(2)
2.093(3)
2.086(3)
1.890(3)
1.987(3)
2.4255(7)
2.4438(7)
C(1)-O(1)
C(2)-N(1)
B(1)-O(2)
B(1)-O(3)
B(2)-O(4)
B(2)-O(5)
1.146(3)
1.164(3)
1.427(4)
1.418(4)
1.424(4)
1.421(4)
1.908(3)
1.943(3)
2.166(3)
2.3512(7)
2.3637(7)
1.141(4)
C(11)-C(16)
C(11)-C(12)
C(12)-C(13)
C(13)-C(14)
C(14)-C(15)
C(15)-C(16)
Interatomic Angles
Interatomic Angles
C(1)-Ru-B(1)
C(1)-Ru-B(2)
C(1)-Ru-C(2)
C(1)-Ru-P(1)
C(1)-Ru-P(2)
C(2)-Ru-B(1)
C(2)-Ru-B(2)
C(2)-Ru-P(1)
C(2)-Ru-P(2)
85.25(13)
85.55(12)
170.52(11)
87.69(9)
P(1)-Ru-P(2)
P(1)-Ru-B(1)
P(1)-Ru-B(2)
P(2)-Ru-B(1)
P(2)-Ru-B(2)
B(1)-Ru-B(2)
O(1)-C(1)-Ru
N(1)-C(2)-Ru
104.00(3)
165.69(9)
91.50(9)
89.45(9)
163.83(9)
75.57(12)
176.1(3)
178.5(2)
H(1)-Os-C(2)
H(1)-Os-C(1)
C(2)-Os-C(1)
H(1)-Os-C(12)
C(2)-Os-C(12)
C(1)-Os-C(12)
H(1)-Os-P(1)
C(2)-Os-P(1)
C(1)-Os-P(1)
C(12)-Os-P(1)
H(1)-Os-P(2)
C(2)-Os-P(2)
C(1)-Os-P(2)
C(12)-Os-P(2)
P(1)-Os-P(2)
85.4(11) C(31)-P(1)-C(21)
176.4(11) C(11)-P(1)-Os
96.47(13) C(31)-P(1)-Os
86.1(11) C(21)-P(1)-Os
168.24(12) O(1)-C(1)-Os
91.68(11) O(2)-C(2)-Os
86.7(11) C(16)-C(11)-C(12) 123.4(3)
105.15(9) C(16)-C(11)-P(1)
89.82(8) C(12)-C(11)-P(1)
66.28(8) C(13)-C(12)-C(11) 116.5(3)
85.5(11) C(13)-C(12)-Os
92.49(9) C(11)-C(12)-Os
97.46(8) C(14)-C(13)-C(12) 120.2(3)
94.86(8) C(15)-C(14)-C(13) 121.6(3)
160.07(3) C(16)-C(15)-C(14) 120.2(3)
104.86(13)
87.64(9)
119.21(9)
122.26(10)
174.8(3)
99.45(9)
91.56(12)
85.01(12)
93.41(8)
177.9(3)
137.0(2)
99.58(19)
89.43(8)
Ta ble 10. Selected Bon d Dista n ces (Å) a n d An gles
(d eg) for Com p lex 12
137.3(2)
106.27(19)
Interatomic Distances
1.901(8)
1.941(6)
2.151(6)
2.4421(14)
2.4477(14)
2.4757(16)
Os-C(1)
Os-C(2)
Os-C(4)
Os-P(2)
Os-P(1)
Os-Cl(1)
Cl(2)-C(3)
Cl(4)-C(4)
Cl(3)-C(3)
O(1)-C(1)
O(2)-C(2)
C(3)-C(4)
1.707(8)
1.847(7)
1.768(7)
1.034(8)
1.128(7)
1.293(9)
C(11)-P(1)-C(31) 111.53(13) C(15)-C(16)-C(11) 118.0(3)
C(11)-P(1)-C(21) 109.88(14)
Ta ble 7. Selected Bon d Dista n ces (Å) a n d An gles
(d eg) for Com p lex 8
Interatomic Angles
C(1)-Os-C(2)
C(1)-Os-C(4)
C(2)-Os-C(4)
C(1)-Os-P(2)
C(2)-Os-P(2)
C(4)-Os-P(2)
C(1)-Os-P(1)
C(2)-Os-P(1)
C(4)-Os-P(1)
P(2)-Os-P(1)
C(1)-Os-Cl(1)
C(2)-Os-Cl(1)
93.(2)
94.4(2)
C(4)-Os-Cl(1)
P(2)-Os-Cl(1)
P(1)-Os-Cl(1)
O(1)-C(1)-Os
O(2)-C(2)-Os
C(4)-C(3)-Cl(2)
C(4)-C(3)-Cl(3)
Cl(2)-C(3)-Cl(3)
C(3)-C(4)-Cl(4)
C(3)-C(4)-Os
Cl(4)-C(4)-Os
92.22(18)
84.89(5)
95.83(5)
175.2(6)
174.6(5)
121.9(5)
126.7(6)
111.3(4)
110.9(5)
134.2(5)
114.7(3)
Interatomic Distances
Os-B(1)
Os-B(2)
Os-C(1)
Os-C(14)
Os-P(1)
Os-P(2)
2.104(6)
2.093(6)
1.892(5)
1.986(5)
2.4134(12)
2.4305(13)
C(1)-O(1)
1.160(5)
1.162(6)
1.434(7)
1.422(7)
1.439(6)
1.428(6)
172.3(3)
94.22(18)
88.78(17)
92.57(16)
85.13(18)
91.84(17)
86.89(16)
179.12(5)
173.31(18)
80.39(18)
C(2)-N
B(1)-O(2)
B(1)-O(3)
B(2)-O(4)
B(2)-O(5)
Interatomic Angles
C(1)-Os-B(1)
C(1)-Os-B(2)
C(1)-Os-C(2)
C(1)-Os-P(1)
C(1)-Os-P(2)
C(2)-Os-B(1)
C(2)-Os-B(2)
C(2)-Os-P(1)
C(2)-Os-P(2)
85.2(2)
85.9(2)
171.0(2)
87.77(15)
99.03(15)
92.1(2)
85.1(2)
93.12(14)
89.49(14)
P(1)-Os-P(2)
P(1)-Os-B(1)
P(1)-Os-B(2)
P(2)-Os-B(1)
P(2)-Os-B(2)
B(1)-Os-B(2)
O(1)-C(1)-Os
N-C(2)-Os
103.75(4)
166.32(17)
90.82(15)
88.95(16)
164.73(15)
77.0(2)
Ta ble 11. Selected Bon d Dista n ces (Å) a n d An gles
(d eg) for Com p lex 16
176.4(4)
178.5(4)
Interatomic Distances
Os-B
2.090(3)
1.938(3)
1.944(3)
2.8346(2)
2.3995(6)
Os-P(2)
C(1)-O(1)
C(2)-O(2)
B-O(3)
2.3821(6)
1.137(3)
1.130(3)
1.415(3)
1.410(4)
Os-C(1)
Os-C(2)
Os-I
Ta ble 8. Selected Bon d Dista n ces (Å) a n d An gles
(d eg) for Com p lex 10
Os-P(1)
B-O(4)
Interatomic Distances
Interatomic Angles
Ru-B(1)
Ru-B(2)
Ru-C(1)
Ru-C(2)
Ru-P(1)
Ru-P(2)
2.100(3)
2.095(4)
1.919(3)
1.914(3)
2.4508(8)
2.4583(9)
C(1)-O(1)
C(2)-O(2)
B(1)-O(3)
B(1)-O(4)
B(2)-O(5)
B(2)-O(6)
1.143(4)
1.140(4)
1.412(4)
1.404(4)
1.417(4)
1.409(4)
C(1)-Os-B
C(1)-Os-C(2)
C(1)-Os-I
C(1)-Os-P(1)
C(1)-Os-P(2)
C(2)-Os-B
C(2)-Os-I
C(2)-Os-P(1)
C(2)-Os-P(2)
84.85(12)
166.93(12)
98.68(8)
90.01(8)
88.53(8)
82.60(12)
94.09(8)
93.54(8)
88.12(8)
P(1)-Os-P(2)
178.19(2)
88.656(16)
89.65(8)
92.493(16)
91.30(8)
174.88(8)
173.6(3)
173.8(3)
P(1)-Os-I
P(1)-Os-B
P(2)-Os-I
P(2)-Os-B
I-Os-B
Interatomic Angles
O(1)-C(1)-Os
O(2)-C(2)-Os
C(1)-Ru-B(1)
C(1)-Ru-B(2)
C(1)-Ru-C(2)
C(1)-Ru-P(1)
C(1)-Ru-P(2)
C(2)-Ru-B(1)
C(2)-Ru-B(2)
C(2)-Ru-P(1)
C(2)-Ru-P(2)
86.01(13)
86.94(15)
171.09(14)
97.64(10)
88.65(11)
87.25(13)
85.73(14)
87.12(10)
96.90(10)
P(1)-Ru-P(2)
P(1)-Ru-B(1)
P(1)-Ru-B(2)
P(2)-Ru-B(1)
P(2)-Ru-B(2)
B(1)-Ru-B(2)
O(1)-C(1)-Ru
O(2)-C(2)-Ru
109.51(3)
162.46(10)
87.59(10)
87.65(10)
162.76(10)
75.43(14)
177.2(3)
Os-CO bond distance for the carbonyl ligand trans to
the Bcat ligand is significantly longer (1.968(5) Å) than
the Os-CO bond distance for the carbonyl ligand which
is trans to the iodide ligand (1.867(4) Å) and longer even
than the Os-CO bond distances for the mutually trans
CO ligands in 16. These observations are consistent
with the Bcat ligand having a large trans influence and
considerable π-acceptor character. In 18, where Bcat
and CO are trans to one another, the Os-B bond
distance (2.145(5) Å) is much longer than the corre-
sponding distance in 16 (2.090(3) Å). This further
176.8(3)
shorter than the Os-B bond distance for the cis isomer
(see below).
In complex 18, despite being trans to a carbonyl
ligand, the Os-I bond length is 2.7883(3) Å, a distance
that is much shorter than that found in 16. Also, the

4352 Organometallics, Vol. 19, No. 21, 2000
Rickard et al.
F igu r e 3. Molecular structure of Ru(Bcat)2(CO)2(PPh3)2
(10) with thermal ellipsoids at the 50% probability level.
F igu r e 1. Molecular structure of Os(C6H4PPh2)H(CO)2-
(PPh3) (5) with thermal ellipsoids at the 50% probability
level.
F igu r e 2. Molecular structure of Os(Bcat)2(CO)(CN-p-
tolyl)(PPh3)2 (8) with thermal ellipsoids at the 50% prob-
ability level.
F igu r e 4. Molecular structure of Ru(Bcat)2(CO)(CN-p-
tolyl)(PPh3)2 (11) with thermal ellipsoids at the 50%
probability level.
Ta ble 12. Selected Bon d Dista n ces (Å) a n d An gles
(d eg) for Com p lex 18
is tilted by 2.41(8)° with respect to the plane of best fit
through the Os, B, C(1), C(2), and I atoms.
Interatomic Distances
Os-B
2.145(5)
1.867(4)
1.968(5)
2.7883(3)
2.3934(10)
Os-P(2)
C(1)-O(1)
C(2)-O(2)
B-O(3)
2.3972(10)
1.155(5)
1.094(5)
1.419(5)
1.408(5)
Con clu sion s
Os-C(1)
Os-C(2)
Os-I
The successful synthesis and characterization of
compounds with either cis or trans arrangements of
Os-B and Os-C(aryl) reveals that the cis arrangement
readily undergoes reductive elimination of organobo-
rane, thus verifying theoretical predictions. In contrast
the trans isomer is stable in this respect. The elimina-
tion process offers a simple route to four-coordinate
osmium(0) complexes which have been trapped through
oxidative addition reactions involving B-H, B-B, and
C-Cl bonds. In the absence of trapping reagents ortho-
metalation of one of the triphenylphosphine phenyl
rings occurs. Many of these products have been struc-
turally characterized, including a novel pair of geo-
metrical isomers, cis- and trans-Os(Bcat)I(CO)2(PPh3)2.
The structural parameters of these two compounds
indicate that the Bcat ligand has significant π-acceptor
character. This conclusion is further supported by the
thermal isomerization of cis-Os(Bcat)I(CO)2(PPh3)2 (where
Os-P(1)
B-O(4)
Interatomic Angles
C(1)-Os-B
C(1)-Os-C(2)
C(1)-Os-I
C(1)-Os-P(1)
C(1)-Os-P(2)
C(2)-Os-B
C(2)-Os-I
C(2)-Os-P(1)
C(2)-Os-P(2)
84.52(18)
93.85(17)
170.37(13)
90.46(12)
91.97(12)
178.35(17)
95.76(12)
91.34(12)
92.06(12)
P(1)-Os-P(2)
175.68(4)
88.84(2)
88.47(12)
88.17(2)
88.20(12)
85.87(12)
178.1(4)
173.6(4)
P(1)-Os-I
P(1)-Os-B
P(2)-Os-I
P(2)-Os-B
I-Os-B
O(1)-C(1)-Os
O(2)-C(2)-Os
supports the notion that the Bcat ligand is behaving as
a π-acceptor ligand, which in this position is in competi-
tion with CO. Both the iodide and the carbonyl ligand
cis to Bcat in 18 are slightly displaced toward the boryl
ligand at angles of 85.87(12)° and 84.52(18)°, respec-
tively, and the orientation of the plane of the Bcat ligand

Bis(Bcat) Complexes of Os and Ru
Organometallics, Vol. 19, No. 21, 2000 4353
F igu r e 7. Molecular structure of cis-Os(Bcat)I(CO)2(PPh3)2
(18) with thermal ellipsoids at the 50% probability level.
F igu r e 5. Molecular structure of OsCl(CCldCCl2)(CO)2-
(PPh3)2 (12) with thermal ellipsoids at the 50% probability
level.
MHz, respectively. Resonances are quoted in ppm and 1H NMR
spectra referenced to either tetramethylsilane (0.00 ppm) or
the proteo impurity in the solvent (7.25 ppm for CHCl3). 13C
NMR spectra were referenced to CDCl3 (77.00 ppm), 31P NMR
spectra to 85% orthophosphoric acid (0.00 ppm) as an external
standard, and 11B NMR spectra to BF3‚OEt2 as an external
standard. Mass spectra were recorded with a Varian VG 70-
SE mass spectrometer. Elemental analyses were obtained from
the Microanalytical Laboratory, University of Otago.
cis-Os(Bca t)(o-tolyl)(CO)(CN-p-tolyl)(P P h 3)2 (4). A solu-
tion of p-tolylisocyanide (37 mg, 0.32 mmol) in benzene was
added to a solution of Os(Bcat)(o-tolyl)(CO)(PPh3)2 (252 mg,
0.264 mmol) in benzene (20 mL), whereupon the mixture
became a pale yellow color. The solution was concentrated to
ca. 1 mL in vacuo and hexane then added to give pure 4 as a
white microcrystalline solid, which was collected on a glass
frit and washed with EtOH and hexane (yield 256 mg, 90%).
Anal. Calcd for C58H48BNO3OsP2: C, 65.11; H, 4.52. Found:
C, 65.20; H, 4.31.
Os(C6H4P P h 2)H(CO)2(P P h 3) (5). A solution of cis-Os-
(Bcat)(o-tolyl)(CO)2(PPh3)2 (151 mg, 0.154 mmol) in benzene
(10 mL) was stirred at 20 °C for 16 h. The resulting solution
was filtered, and the benzene was then removed in vacuo. The
solid residue was recrystallized from CH2Cl2/EtOH to give pure
5 as a white microcrystalline solid, which was collected on a
glass frit and washed with EtOH and hexane (yield 95 mg,
F igu r e 6. Molecular structure of trans-Os(Bcat)I(CO)2-
(PPh3)2 (16) with thermal ellipsoids at the 50% probability
level.
2
80%). 31P NMR (CDCl3): δ -65.58 (d, J PP ) 218 Hz), 13.95
Bcat is trans to CO) to trans-Os(Bcat)I(CO)2(PPh3)2
(where Bcat is trans to I and the two CO ligands are
mutually trans).
2
(d, J PP ) 217 Hz). Anal. Calcd for C38H30O2OsP2: C, 59.21;
H, 3.92. Found: C, 59.17; H, 3.82.
o-tolylBca t. The filtrate obtained in the recrystallization
of 5 from CH2Cl2/EtOH above was dissolved in light petroleum
and filtered. The solvent was then removed in vacuo to give
crude o-tolyl-Bcat as a white solid. It was not possible to
completely purify the sample, and hence acceptable elemental
analysis was not obtained. The compound was characterized
by 1H and 13C NMR spectroscopy (see Tables 2 and 3), 11B NMR
spectroscopy (CDCl3, δ, 32.3 ppm), and mass spectrometry,
which showed a prominent signal corresponding to the mo-
lecular ion (EI+, m/z ) 210).
Exp er im en ta l Section
Gen er a l Con sid er a tion s. The general experimental and
spectroscopic techniques employed in this work were the same
as those described previously.11 Os(Bcat)Cl(CO)(PPh3)2,5 Os-
(Bcat)(o-tolyl)(CO)(PPh3)2,4 trans-Os(Bcat)(o-tolyl)(CO)2(PPh3)2,4
Ru(CO)2(PPh3)3,12 and Ru(CO)(CN-p-tolyl)(PPh3)3 were pre-
13
pared as reported previously.
Infrared spectra (4000-400 cm-1) were recorded as Nujol
mulls between KBr plates on a Perkin-Elmer Paragon 1000
spectrometer. NMR spectra were obtained on a Bruker DRX
400 at 25 °C. 1H, 13C, 11B, and 31P NMR spectra were obtained
operating at 400.1 (1H), 100.6 (13C), 128.0 (11B), and 162.0 (31P)
Os(C6H4P P h 2)H(CO)(CN-p-tolyl)(P P h 3) (6a a n d 6b). A
solution of cis-Os(Bcat)(o-tolyl)(CO)(CN-p-tolyl)(PPh3)2 (87 mg,
0.081 mmol) in benzene (10 mL) was stirred at 20 °C for 16 h.
The resulting cloudy solution was filtered through Celite, and
the benzene was then removed in vacuo. The resulting solid
residue was recrystallized from CH2Cl2/EtOH to give 6 as a
pale yellow microcrystalline solid, which was collected on a
glass frit and washed quickly with hexane (yield 34 mg, 49%).
The product could not be obtained in highly pure form due to
(11) Maddock, S. M.; Rickard, C. E. F.; Roper, W. R.; Wright, L. J .
Organometallics 1996, 15, 1793.
(12) Cavit, B. E.; Grundy, K. R.; Roper, W. R. J . Chem. Soc., Chem.
Commun. 1972, 60.
(13) Christian, D. F.; Clark, G. R.; Roper, W. R.; Waters, J . M.;
Whittle, K. R. J . Chem. Soc., Chem. Commun. 1972, 458.

4354 Organometallics, Vol. 19, No. 21, 2000
Rickard et al.
its high solubility in organic solvents. 1H and 31P NMR
spectroscopy showed that the product exists as two isomers
in a ratio of approximately 2:1. 31P NMR (CDCl3) major
isomer: δ -62.46 (d, 2J PP ) 232 Hz), 16.50 (d, 2J PP ) 232 Hz).
Minor isomer: δ -63.59 (d, J PP ) 230 Hz), 17.29 (d, J PP ) 230
Hz). Anal. Calcd for C45H37NOOsP2: C, 62.85; H, 4.34; N, 1.63.
Found: C, 61.85; H, 4.43; N, 1.50.
Os(Bca t)2(CO)(CN-p-tolyl)(P P h 3)2 (8). A mixture of cis-
Os(Bcat)(o-tolyl)(CO)(CN-p-tolyl)(PPh3)2 (104 mg, 0.0972 mmol)
and B2cat2 (46 mg, 0.19 mmol) was dissolved in benzene (12
mL), and the colorless solution was stirred at 20 °C for 16 h.
The benzene was removed in vacuo from the resulting pale
yellow solution, and then CH2Cl2 (10 mL) was added to the
solid residue. The resulting suspension was filtered through
Celite, and EtOH (5 mL) was added to the filtrate. The CH2-
Cl2 was removed in vacuo to give pure 8 as a white microc-
rystalline solid, which was collected on a glass frit and washed
with EtOH and hexane (yield 92 mg, 86%). Anal. Calcd for
cis-Os(Bca t)Cl(CO)2(P P h 3)2 (13). A stream of CO gas was
passed through a solution of Os(Bcat)Cl(CO)(PPh3)2 (100 mg,
0.111 mmol) in CH2Cl2 (10 mL) for 5 s, turning it colorless.
Addition of EtOH (10 mL) and removal of the CH2Cl2 in vacuo
gave pure 13 as a white microcrystalline solid, which was
collected on a glass frit and washed with EtOH and hexane
(yield 93 mg, 90%). Anal. Calcd for C44H34BClO4OsP2: C, 57.12;
H, 3.70. Found: C, 56.82; H, 3.49.
tr a n s-Os(Bca t)(P h )(CO)2(P P h 3)2 (14). A solution of LiPh
in Et2O (0.82 M, 0.32 mL, 0.27 mmol) was added slowly to a
rapidly stirred colorless solution of cis-Os(Bcat)Cl(CO)2(PPh3)2
(205 mg, 0.222 mmol) in benzene (15 mL) at 5 °C, turning the
mixture pale yellow and cloudy. The mixture was allowed to
warm to 20 °C and then stirred for 30 min. The benzene was
then removed in vacuo and the solid residue dissolved in
CH2Cl2 (10 mL). Addition of EtOH (5 mL) followed by re-
moval of the CH2Cl2 in vacuo gave pure 14 as a white micro-
crystalline solid, which was collected on a glass frit and washed
with EtOH and hexane (yield 137 mg, 64%). Anal. Calcd for
C50H39BO4OsP2: C, 62.12; H, 4.07. Found: C, 61.96; H, 4.14.
tr a n s-Os(Bca t)I(CO)2(P P h 3)2 (16). Meth od 1. A mixture
of trans-Os(Bcat)(o-tolyl)(CO)2(PPh3)2 (107 mg, 0.109 mmol)
and I2 (34 mg, 0.13 mmol) was dissolved in CH2Cl2 (15 mL) to
give a purple solution, which was stirred for 3 h. Addition of
EtOH to the resulting orange solution followed by removal of
the CH2Cl2 in vacuo gave a yellow solid, which was collected
on a glass frit and washed with EtOH and hexane. This solid
was then dissolved in CH2Cl2 and passed down a column (silica
gel/CH2Cl2/hexane, 1:1 as eluant). The first fraction to elute
was yellow, and removal of the solvent in vacuo followed by
recrystallization from CH2Cl2/EtOH afforded pure trans-Os-
(o-tolyl)I(CO)2(PPh3)2 (yield 45 mg, 42%). IR (KBr, Nujol):
ν(CO) ) 1947vs cm-1. Anal. Calcd for C45H37IO2OsP2: C, 54.66;
H, 3.77. Found: C, 54.57; H, 3.86.
The second fraction was colorless, and collection and re-
moval of solvent in vacuo, followed by recrystallization from
CH2Cl2/EtOH, afforded pure trans-Os(Bcat)I(CO)2(PPh3)2 as
colorless crystals (yield 54 mg, 49%). 1H NMR spectroscopy
showed 0.8 equiv of CH2Cl2 present as solvate. Anal. Calcd
for C44H34BIO4OsP2‚0.8CH2Cl2: C, 49.63; H, 3.31. Found: C,
49.66; H, 3.18.
Meth od 2. A solution of cis-Os(Bcat)I(CO)2(PPh3)2 (141 mg,
0.14 mmol) in toluene (20 mL) was heated under reflux for 1
h. The solution was cooled to 20 °C and concentrated to ca. 1
mL in vacuo. Addition of hexane gave pure 16 as a white
microcrystalline solid, which was collected on a glass frit and
washed with EtOH and hexane (yield 102 mg, 72%). Charac-
terization was by comparison of spectral properties with those
of a sample prepared as above.
cis-Os(Bca t)I(CO)2(P P h 3)2 (18). A solution of NaI (0.460
mg, 3.07 mmol) in EtOH (5 mL) was added to a solution of
Os(Ph)Cl(CO)(PPh3)2 (263 mg, 0.307 mmol) in CH2Cl2 (15 mL),
and the resulting mixture was stirred for 30 min to give a deep
red cloudy solution. The solvent was removed in vacuo and
the residue extracted into CH2Cl2 and filtered through Celite.
The solvent was removed from the filtrate in vacuo, and a
solution of HBcat (0.035 mL, 0.33 mmol) in benzene (15 mL)
was then added. The dark red mixture was heated under reflux
for 20 min to give an orange solution, which was cooled to 20
°C. A stream of CO gas was then passed through the solution
for 20 s, turning it yellow. The benzene was removed in vacuo
and the solid residue dissolved in CH2Cl2 (10 mL). Addition of
EtOH (10 mL) followed by removal of the CH2Cl2 in vacuo gave
pure 18 as a white microcrystalline solid, which was collected
on a glass frit and washed with EtOH and hexane (yield 213
mg, 68%). Anal. Calcd for C44H34BIO4OsP2: C, 51.98; H, 3.37.
Found: C, 51.89; H, 3.40.
C
57H45B2NO5OsP2: C, 62.37; H, 4.13; N, 1.28. Found: C, 62.10;
H, 4.08; N, 1.49.
Os(Bca t)H(CO)2(P P h 3)2 (9). A mixture of cis-Os(Bcat)(o-
tolyl)(CO)2(PPh3)2 (106 mg, 0.108 mmol) and HBcat (0.020 mL,
0.19 mmol) was dissolved in benzene (12 mL), and the colorless
solution was stirred at 20 °C for 16 h. The benzene was
removed in vacuo from the resulting orange suspension, and
then CH2Cl2 (10 mL) was added to the solid residue. The
resulting suspension was filtered through Celite, and EtOH
(5 mL) was added to the filtrate. Removal of the CH2Cl2 in
vacuo gave 9 as a white microcrystalline solid, which was
collected on a glass frit and washed with EtOH and hexane
(yield 90 mg, 93%). Anal. Calcd for C44H35BO4OsP2: C, 59.33;
H, 3.96. Found: C, 59.11; H, 3.78.
Ru (Bca t)2(CO)2(P P h 3)2 (10). A mixture of Ru(CO)2(PPh3)3
(200 mg, 0.212 mmol) and B2cat2 (62 mg, 0.26 mmol) was
dissolved in toluene (15 mL), and the yellow solution was
irradiated for 5 min by a 1000 W tungsten-halogen lamp held
10 cm from the flask. The solution was then stirred at 20 °C
for 1.5 h without irradiation. The solvent was removed in vacuo
from the resulting pale yellow solution, and CH2Cl2 (10 mL)
was added to the solid residue. Addition of EtOH (10 mL) and
removal of the CH2Cl2 in vacuo gave pure 10 as a white
microcrystalline solid, which was collected on a glass frit and
washed with EtOH and hexane (yield 97 mg, 50%). X-ray
diffraction analysis confirmed 1 equiv of toluene present as
solvate in the single crystal used for the X-ray analysis. Anal.
Calcd for C50H38B2O6P2Ru‚C7H8: C, 67.68; H, 4.58. Found: C,
67.73; H, 4.52.
Ru (Bca t)2(CO)(CN-p-tolyl)(P P h 3)2 (11). A mixture of Ru-
(CO)(CN-p-tolyl)(PPh3)3 (150 mg, 0.145 mmol) and B2cat2 (47
mg, 0.20 mmol) was dissolved in benzene (15 mL) and the
orange solution irradiated for 5 min by a 1000 W tungsten-
halogen lamp held 10 cm from the flask. The solution was then
stirred at 20 °C for 1.5 h without irradiation. The solvent was
removed from the resulting pale yellow solution in vacuo, and
CH2Cl2 (10 mL) was added. Addition of EtOH (10 mL) and
removal of the CH2Cl2 in vacuo gave pure 11 as a white
microcrystalline solid, which was collected on a glass frit and
1
washed with EtOH and hexane (yield 68 mg, 47%). H NMR
spectroscopy showed 0.25 equiv of CH2Cl2 present as solvate.
Anal. Calcd for C57H45B2NO5P2Ru‚0.25 CH2Cl2: C, 66.79; H,
4.45; N, 1.36. Found: C, 66.93; H, 4.34; N, 1.24.
Os(CCldCCl2)Cl(CO)2(P P h 3)2 (12). A colorless solution of
cis-Os(Bcat)(o-tolyl)(CO)2(PPh3)2 (100 mg, 0.102 mmol) and
C2Cl4 (0.50 mL, 4.9 mmol) in benzene (12 mL) was stirred for
16 h at 20 °C to give a pale yellow solution. The benzene
was removed in vacuo, and the solid residue was dissolved in
CH2Cl2 (10 mL). Addition of EtOH (5 mL) followed by removal
of the CH2Cl2 in vacuo gave pure 12 as a white microcrystalline
solid, which was collected on a glass frit and washed with
X-r a y Diffr a ction Stu d ies of 5, 8, 10, 11, 12, 16, a n d 18.
Intensity data were collected using a Bruker SMART diffrac-
tometer. Data collection covered either a sphere or hemisphere,
and unit cell parameters were from all data with I > 10σ(I).
EtOH and hexane (yield 68 mg, 71%). Anal. Calcd for C40H30
Cl4O2OsP2: C, 51.29; H, 3.23. Found: C, 51.76; H, 3.29.
-

Bis(Bcat) Complexes of Os and Ru
Organometallics, Vol. 19, No. 21, 2000 4355
Data were corrected for Lorentz and polarization effects and
empirical absorption corrections (SADABS) applied.
Structure solution was by Patterson and difference Fourier
methods, and refinement was by full-matrix least-squares of
F2. All non-hydrogen atoms were allowed to refine anisotro-
pically. Hydrogen atoms were placed geometrically and refined
with a riding model with thermal parameters fixed at 20%
(50% for methyl groups) greater than the carrier atom. Data
collection and refinement parameters are summarized in
Table 5.
Ack n ow led gm en t. We thank the Marsden Fund,
administered by the Royal Society of New Zealand, for
supporting this work and for granting a Postdoctoral
Fellowship award to A.W.
Su p p or tin g In for m a tion Ava ila ble: Tables of crystal
data, collection and refinement parameters, positional and
anisotropic displacement parameters, and bond distances and
angles for 5, 8, 10, 11, 12, 16, and 18. This material is available
free of charge via the Internet at http://pubs.acs.org.
Programs used for structure solution were SHELXS-97 (G.
M. Sheldrick, University of Go¨ttingen, 1997) and SHELXL-
97 (G. M. Sheldrick, University of Go¨ttingen, 1997).
OM0004601