A series of neutral and cationic mesityleneosmium(II) complexes containing bulky phosphines with various functionalities as ligands

Article abstract of DOI:10.1021/om980909e

Mono- and dihydridoosmium(II) compounds with [(mes)Os{iPr₂P(CH₂)_nY}] (mes = mesitylene, 1,3,5-trimethylbenzene; n = 2, Y = NMe₂, OMe; n = 3, Y = NMe₂) as a molecular unit are prepared from the dichlor

Full text of DOI:10.1021/om980909e

Organometallics 1999, 18, 1185-1195
1185
A Ser ies of Neu tr a l a n d Ca tion ic Mesitylen eosm iu m (II)
Com p lexes Con ta in in g Bu lk y P h osp h in es w ith Va r iou s
F u n ction a lities a s Liga n d s
Helmut Werner,*,† Gerhard Henig,† Bettina Windmu¨ller,† Olaf Gevert,†
Christopher Lehmann,‡ and Regine Herbst-Irmer‡
Institut fu¨r Anorganische Chemie, Universita¨t Wu¨rzburg, Am Hubland,
D-97074 Wu¨rzburg, Germany, and Institut fu¨r Anorganische Chemie, Universita¨t Go¨ttingen,
Tammannstrasse 4, D-37077 Go¨ttingen, Germany
Received November 6, 1998
Mono- and dihydridoosmium(II) compounds with [(mes)Os{iPr2P(CH2)nY}] (mes ) mesi-
tylene, 1,3,5-trimethylbenzene; n ) 2, Y ) NMe2, OMe; n ) 3, Y ) NMe2) as a molecular
unit are prepared from the dichloro derivatives [(mes)OsCl2{iPr2P(CH2)nY}] and magnesium
amalgam in THF in the presence of ethanol. Upon treatment of [(mes)Os(X)Cl{κ1(P)-iPr2P-
(CH2)2Y}] (X ) H, Cl) with AgPF6 in CH2Cl2 cationic complexes with iPr2P(CH2)2Y as a
chelating ligand are obtained. The compounds with Y ) OMe react (for X ) Cl) with L )
CO and CNMe by opening of the chelate bond to give the PF6 salts [(mes)Os(L)Cl{κ1(P)-
iPr2P(CH2)2Y}]PF6 and (for X ) H) with KOtBu by fragmentation of the functionalized
phosphine to afford the neutral complex [(mes)OsH(OMe)(iPr2PCHdCH2)]. The reaction of
the chelate compound [(mes)OsCl{κ2(P,O)-iPr2PCH2C(OMe)O}]PF6 with KOtBu leads to the
formation of the corresponding uncharged phosphanyl ester enolate-osmium(II) complex
by proton abstraction from the PCH2 unit. The ester enolate complex reacts with phenyl
isocyanate and diphenylketene by insertion of the heterocumulene into the enolate C-H
bond and with water by ester hydrolysis to yield the phosphanyl carboxylate derivative [(mes)-
OsCl(κ2(P,O)-iPr2PCH2CO2)]. The molecular structures of compounds 9, 11, 22, and 23 have
been determined by X-ray crystallography.
In tr od u ction
enolate-metal complexes have been prepared and found
to be useful starting materials for C-C coupling reac-
tions with activated alkynes and isocyanates4 as well
as for the reversible binding of carbon dioxide.5
Owing to their important role in homogeneous ca-
talysis,1,2 the chemistry of functionalized phosphines of
the general composition R2P(CH2)nY and their transi-
tion-metal complexes has been an area of active re-
search in recent years.3 In particular for compounds
where Y is OMe, C(O)R′, or CO2R′, the oxygen donor
atoms are able to protect temporarily a vacant coordina-
tion site and thus allow the addition of other (better)
donor ligands to the metal center under fairly mild
conditions. Moreover, with â-phosphanyl ketones or
esters as starting materials a number of phosphanyl
In a continuation of our work on the behavior of
[(mes)OsCl2]n (1) toward trialkylphosphines,6 we re-
cently reported the synthesis of the monomeric com-
pounds [(mes)OsCl2(L)] with phosphanyl ethers and
phosphanyl esters as ligands.7 We also illustrated that,
depending on the reaction conditions, the corresponding
complex with L ) iPr2PCH2CO2Me reacts with hydride
sources to give either the dihydridoosmium(II) deriva-
tive [(mes)OsH2(L)] or, by elimination of HCl, the novel
phosphanylmethanide compound [(mes)OsCl{κ2(P,C)-
iPr2PCHCO2Me}].7 In this paper we describe the prepa-
ration of a series of neutral mesityleneosmium(II)
complexes with bulky phosphines containing dimethyl-
amino, methoxy, or carbomethoxy functionalities, their
conversion into cationic species, and the reactivity of
these cations toward nucleophilic and electrophilic
† Universita¨t Wu¨rzburg.
‡ Universita¨t Go¨ttingen.
(1) (a) Keim, W. J . Mol. Catal. 1989, 52, 19-25. (b) Britovsek, G. J .
P.; Keim, W.; Mecking, S.; Sainz, D.; Wagner, T. J . Chem. Soc., Chem.
Commun. 1993, 1632-1634. (c) Keim, W.; Maas, H.; Mecking, S. Z.
Naturforsch., B: Anorg. Chem., Org. Chem. 1995, 50, 430-438.
(2) (a) Lindner, E.; Meyer, S.; Wegner, P.; Karle, B.; Sickinger, A.;
Steger, B. J . Organomet. Chem. 1987, 335, 59-70. (b) Braunstein, P.;
Chauvin, Y.; Mercier, S.; Saussine, L.; De Cian, A.; Fischer, J . J . Chem.
Soc., Chem. Commun. 1994, 2203-2204. (c) Matt, D.; Huhn, M.;
Bonnet, M.; Tkatchenko, I.; Englert, U.; Kla¨ui, W. Inorg. Chem. 1995,
34, 1288-1291.
(3) (a) J effrey, J . C.; Rauchfuss, T. B. Inorg. Chem. 1979, 18, 2658-
2666. (b) Bader, A.; Lindner, E. Coord. Chem. Rev. 1991, 108, 27-
110. (c) Lindner, E.; Pautz, S.; Haustein, M. Coord. Chem. Rev. 1996,
155, 145-162.
(5) (a) Braunstein, P.; Matt, D.; Dusausoy, Y.; Fischer, J .; Mitschler,
A.; Ricard, L. J . Am. Chem. Soc. 1981, 103, 5115-5125. (b) Braunstein,
P.; Matt, D.; Nobel, D. Chem. Rev. 1988, 88, 747-764.
(6) Werner, H.; Stahl, S.; Kohlmann, W. J . Organomet. Chem. 1991,
409, 285-289.
(7) Werner, H.; Henig, G.; Wecker, U.; Mahr, N.; Peters, K.; von
Schnering, H. G. Chem. Ber. 1995, 128, 1175-1181.
(8) Henig, G.; Werner, H.; Wecker; U. International Symposium on
Molecular Reaction Mechanisms involving Transition Metals; Florence,
1994, Abstr. p 56.
(4) (a) Bouaoud, S.-E.; Braunstein, P.; Grandjean, D.; Matt, D.;
Nobel, D. Inorg. Chem. 1988, 27, 2279-2286. (b) Braunstein, P.; Gomes
Carneiro, T. M.; Matt, D.; Balegroune, F.; Grandjean, D. Organome-
tallics 1989, 8, 1737-1743. (c) Braunstein, P.; Nobel, D. Chem. Rev.
1989, 89, 1927-1945.
(9) Polzer, T.; Ellebracht, A.; Kiefer, W.; Wecker, U.; Werner, H. J .
Organomet. Chem. 1992, 438, 319-328.
10.1021/om980909e CCC: $18.00 © 1999 American Chemical Society
Publication on Web 03/04/1999

1186 Organometallics, Vol. 18, No. 7, 1999
Werner et al.
Sch em e 1
Sch em e 2
derivative [(mes)OsHCl(κ1(P)-iPr2PCH2CH2CO2Et)],7 com-
pound 9 forms yellow, slightly air-sensitive crystals
which (even under argon) slowly decompose at room
temperature but can be stored at -20 °C for weeks.
With regard to the spectroscopic data of 9 we note that
owing to the chirality of the molecule the protons of the
CH2 units of the functionalized phosphines are diaste-
reotopic and thus four multiplets are observed. The
same happens for the CH3 protons of the isopropyl
groups, which give rise to four doublets of doublets in
the range δ 1.17-0.95.
The structure of 9 was confirmed by single-crystal
X-ray structure analysis. The ORTEP structure plot
(Figure 1) reveals that the metal center is coordinated
by the mesitylene ring and the three monodentate
ligands in a piano-stool fashion. Probably due to the
dangling of the phosphanyl ether unit, there is a slight
disorder in the CH2OMe fragment. Although the mesi-
tylene ring is almost planar, the Os-C10 to Os-C15
bond lengths differ by ca. 0.12 Å. The shortest distance
Os-C13 (2.168(5) Å) is that to the ring carbon atom
which is nearest to the hydride ligand, while the longest
distance Os-C10 (2.289(5) Å) is trans to Os-H. Hence,
substrates. Part of this work has already been com-
municated.8
Resu lts a n d Discu ssion
1. Mon o- a n d Dih yd r id oosm iu m (II) Com p ou n d s
w ith [(m es)Os{iP r 2P (CH2)n Y}] a s a Molecu la r Un it.
Under conditions similar to those with phosphanyl
ethers, ketones and esters, the chloro-bridged complex
1 reacts with phosphanylamines iPr2P(CH2)nNMe2 (n
) 2, 3) to give the mononuclear products 2 and 3
(Scheme 1) in almost quantitative yield. They are orange
solids which are practically air-stable and moderately
soluble in polar organic solvents such as CH2Cl2 and
1
acetone. While the H NMR data of 2 and 3 deserve no
further comment, it should be mentioned that the
expected singlet in the 31P NMR spectra is associated
1
with two satellites arising from J (187Os31P) coupling of
ca. 277 Hz.
The experiments aimed at substituting the chloro
ligands in 2 and 3 by hydride ions led to some unex-
pected results. When we tried to prepare the complexes
[(mes)OsH2(L)] (6, 7) from the precursors 2, 3 and Mg/
Hg in THF in the presence of EtOH, following the
method which we applied to the synthesis of the
corresponding dihydridoosmium(II) compounds with L
) CO, CNMe,9 we obtained a mixture of 4 and 6 or 5
and 7, respectively, in different ratios. Despite several
attempts we failed to separate these mixtures by column
chromatography or fractional crystallization. Therefore,
we characterized the chloro hydrido and dihydrido
complexes by spectroscopic techniques. The 1H NMR
spectra of 4 and 5 display a hydride signal at ca. δ -9.0
and those of 6 and 7 at ca. δ -12.1, both of which are
split into a doublet with a large P-H coupling of 38-
44 Hz. The 31P NMR spectra of 4-7 show a singlet
resonance which under off-resonance conditions is split
into either a doublet (4, 5) or a triplet (6, 7).
In contrast to the reactions of 2 and 3, the reaction of
the phosphanyl ether complex 8 with magnesium amal-
gam in THF/EtOH proceeds very selectively and affords
the chlorohydridoosmium(II) derivative 9 (Scheme 2) in
88% isolated yield. Like the related phosphanyl ester
F igu r e 1. ORTEP drawing of 9.

Os(II) Mesitylene Complexes with Phosphine Ligands
Organometallics, Vol. 18, No. 7, 1999 1187
Ta ble 1. Selected Bon d Dista n ces a n d An gles w ith
Esd ’s for Com p ou n d 9
Bond Distances (Å)
Os-Cl
2.419(2)
2.302(2)
2.289(5)
2.274(5)
2.231(5)
Os-C13
Os-C14
Os-C15
C3-C4
C4-O1
2.168(5)
2.197(5)
2.259(5)
1.516(8)
1.344(7)
Os-P
Os-C10
Os-C11
Os-C12
Bond Angles (deg)
Cl-Os-P
P-C3-C4
87.12(6)
117.6(4)
C3-C4-O1
C4-O1-C5
109.4(5)
113.0(5)
Sch em e 3
F igu r e 2. ORTEP drawing of 11.
Ta ble 2. Selected Bon d Dista n ces a n d An gles w ith
Esd ’s for Com p ou n d 11
Bond Distances (Å)
Os1-Cl1
Os1-P1
Os1-N1
Os1-C1
Os1-C2
2.4363(11)
2.3544(11)
2.225(3)
2.250(4)
2.252(4)
Os1-C3
Os1-C4
Os1-C5
Os1-C6
2.254(4)
2.197(5)
2.245(4)
2.197(4)
Bond Angles (deg)
Cl1-Os1-P1
Cl1-Os1-N1
P1-Os1-N1
Os1-P1-C13
87.19(4)
84.22(10)
81.74(10)
103.20(15)
Os1-N1-C12
N1-C12-C13
P1-C13-C12
110.8(3)
111.2(4)
109.0(3)
it seems that both steric requirements and eletronic
effects (i.e., the trans influence of the hydride) are
responsible for the differences in bond lengths. The
distances Os-Cl and Os-P (Table 1) are in the expected
range7,10 and thus deserve no further comment.
nuclei in the 31P NMR spectra of 11-13 is shifted to
lower field by 35-44 ppm compared with the neutral
compounds 2, 8, and 9, respectively. The 1H NMR
spectrum of 13 displays the hydride signal at δ -8.29,
and this is also at lower field compared with 9 (δ
-12.20).
The molecular structure of the cationic complex 11 is
shown in Figure 2, and bond distances and angles are
given in Table 2. The osmium and the functionalized
phosphine form a five-membered chelate ring with a
P-Os-N bond angle of 81.74(10)°. This “bite angle” of
the phosphanylamine is almost identical with that of
the phosphanylethanolate in the related neutral com-
pound [(mes)Os(Ph)(κ2(P,O)-iPr2PCH2CPh2O)] (81.3(1)°),
which was obtained upon treatment of 17 with Ph-
MgBr.7 The Os-N bond length of 11 (2.225(3) Å) is
significantly shorter than in [OsCl(CO)(κ2(C,P)-iPr2-
PCH2CH2NMeCH)(κ2(P,N)-iPr2PCH2CH2NMe2)]Cl (2.333-
(5) Å),11b which we assume is due to the steric crowding
around the metal center in the non-mesitylene-contain-
ing chelate complex.
Treatment of the chloro hydrido complex 9 with a
larger excess of Mg/Hg in THF/EtOH produces in part
the dihydridoosmium(II) derivative 10, which can be
separated from the starting material 9 by chromato-
graphic techniques. The isolated yield of 10 (a colorless,
air-sensitive, and thermally unstable solid) was 58%.
The presence of two hydride ligands is indicated by the
1H NMR spectrum, which displays a doublet at δ -12.20
with an intensity of 2H. Under off-resonance conditions,
in the 31P NMR spectrum a triplet is observed. Attempts
to prepare the dihydrido complex 10 from the dichloro
compound 8 and NaBH4 led to a mixture of 9 and 10 in
the molar ratio of 1:1, indicating that this method is
not an alternative for the synthesis of the OsH2 species.
Both the dichloro compounds 2 and 8 and the chloro
hydrido derivative 9 react with an equimolar amount
of AgPF6 in CH2Cl2 by abstraction of a chloride ligand
to give the cationic complexes 11-13 (Scheme 3) in good
to excellent yield. Compounds 11-13 are yellow solids,
the composition of which has been confirmed not only
by elemental analysis but also by conductivity measure-
ments. Due to the deshielding effect of the positive
charge at the metal center, the signal for the phosphorus
The reactions of compounds 12 and 13 with some
nucleophiles are summarized in Scheme 4. When the
stability of cationic carbonylosmium(II) complexes such
as [(C6H6)OsI(CO)(PR3)]PF6 is taken into account,12 the
(10) Inter alia: (a) Aslanov, L.; Mason, R.; Wheeler, A. G.; Whimp,
P. O. J . Chem. Soc. D 1970, 30-31. (b) Werner, H.; Esteruelas, M. A.;
Otto, H. Organometallics 1986, 5, 2295-2299. (c) Aracama, M.;
Esteruelas, M. A.; Lahoz, F. J .; Lopez, J . A.; Meyer, U.; Oro, L. A.;
Werner, H. Inorg. Chem. 1991, 30, 288-293. (d) Pertici, P.; Pitzalis,
E.; Machetti, F.; Rosini, C.; Salvadori, P.; Bennett, M. A. J . Organomet.
Chem. 1994, 466, 221-231.
(11) (a) Werner, H.; Weber, B.; Nu¨rnberg, O.; Wolf, J . Angew. Chem.
1992, 104, 1105-1107; Angew. Chem., Int. Ed. Engl. 1992, 31, 1025-
1026. (b) Weber, B. Ph.D. Thesis, Universita¨t Wu¨rzburg, 1995.
(12) (a) Werner, H.; Werner, R. Chem. Ber. 1982, 115, 3766-3780.
(b) Roder, K.; Werner, H. Chem. Ber. 1989, 122, 833-840.

1188 Organometallics, Vol. 18, No. 7, 1999
Werner et al.
Sch em e 4
Sch em e 5
somewhat surprising observation is that the corre-
sponding mesitylene compound 14 is rather labile and
decomposes in solution within a few hours. The IR
spectrum of 14 (in CH2Cl2) shows the ν(CO) frequency
at 1990 cm-1, i.e., at a similar position as [(C6H6)OsI-
(CO)(PiPr3)]PF6.12b In contrast to 14, the related methyl
isocyanide derivative 15 is quite stable and can be
stored under argon for weeks. We conclude that the
increase in the thermodynamic stability when CO is
replaced by CNMe is attributed to the stronger donor
ability of the isocyanide, which is also reflected in the
shift of the phosphorus resonance by ca. 8 ppm to higher
field in the 31P NMR spectrum of 15 compared to that
of 14.
metal derivatives 2, 8, and 9, the related phophanyl
ester compound 177 also reacts with AgPF6 in CH2Cl2
to give the chelate complex 19a (Scheme 5) in 85% yield.
An alternative route to this compound as well as to the
-
analogous BF4-, CF3CO2-, and CF3SO3 salts 19b-d
of the [(mes)OsCl{κ2(P,O)-iPr2PCH2C(OMe)O}]+ cation
consists of the reaction of the phosphanylmethanide
complex 18 with acid HX. Compound 18 was obtained
by attempting to prepare the phosphanyl ester enolate-
osmium(II) derivative [(mes)OsCl{κ2(P,O)-iPr2PCHd
C(OMe)O}] from 17 and NaH in the presence of Al2O3.7
With regard to the thermodynamic stability of isomeric
complexes such as 18 and 20 (see Scheme 6), it should
be noted that recent work from our laboratory has
shown that in the corresponding mesityleneruthenium-
(II) system a thermodynamic preference for a three-
instead of a five-membered chelate ring exists.14 The
IR spectra of the yellow, nearly air-stable solids 19a ,b
display a CdO stretching frequency at 1595 cm-1 (19a )
and 1604 cm-1 (19b), which is lowered by ca. 120-130
cm-1 if compared with the frequency for 17.7 We
therefore conclude that the phosphanyl ester ligand in
the cationic species 19a -d is coordinated via the
phosphorus and the carbonyl oxygen (but not the
methoxy group) to the metal center.
The attempt to abstract the coordinated hydride
ligand from 13 by KOtBu led to a puzzling result.
Instead of generating the compound [(mes)Os(κ2(P,O)-
iPr2PCH2CH2OMe)], a cleavage of the C-OMe bond of
the chelate unit occurred and the hydridomethoxy-
osmium(II) complex 16 with diisopropylvinylphosphine
as ligand was formed. The pale yellow oily substance is
readily soluble in common organic solvents and decom-
1
poses slowly at room temperature. The H NMR spec-
trum of 16 displays a doublet resonance at δ -8.55 for
the hydride and three signals for the vinylic protons H1,
H2, and H3 (see Scheme 4) at δ 6.32, 5.59, and 5.44
corresponding to an ABC pattern. These signals appear
in the 1H{31P} spectrum as doublets of doublets with
the expected different H-H coupling for the cis, trans,
and geminal protons of the CHdCH2 fragment. With
regard to the mechanism of formation of 16 we assume
that in the initial step the strong base KOtBu abstracts
a proton from either the OCH3 or the PCH2 moiety of
the functionalized phosphine ligand. The coordinated
iPr2PCHCH2OMe systems, once formed, could be trans-
formed by breaking the H2C-OMe bond to a methoxy
and a vinylphosphine unit, a process that is reminiscent
of the fragmentation of dialkyl ethers by NaNH2,
organoalkali-metal compounds, or other strong bases.13
2. P h osp h a n yl Ester - a n d P h osp h a n yl Ester
En ola te-Osm iu m (II) Com p lexes. Like the above-
mentioned phosphanyl ether and phosphanylamine
In contrast to 17, which upon treatment with bases
gives 18, the cationic complex 19a reacts with KOtBu
in THF to afford the phosphanyl ester enolate compound
20 in excellent yield. The structural proposal (Scheme
6) for the yellow, very moisture-sensitive substance is
1
mainly supported by the H NMR spectrum, in which a
characteristic signal (doublet) for the PCH proton at
δ 3.48 appears. The 13C NMR spectrum of 20 displays
two resonances for the O-C-C-P carbon atoms of the
chelate ring at δ 184.4 (O-C) and 45.6 (C-P), the
chemical shift and the P-C coupling constant of which
are quite similar to those of phosphanyl ester enolate-
ruthenium(II) and -platinum(II) derivatives.5a,14
While compound 20 is inert toward CO2, it reacts with
phenyl isocyanate in benzene to give a mixture of
products, among which the neutral complex 21 is the
(13) (a) Ko¨brich, G. Angew. Chem. 1962, 74, 453-465; Angew.
Chem., Int. Ed. Engl. 1962, 1, 382-399. (b) Maercker, A.; Demuth,
W. J ustus Liebigs Ann. Chem. 1977, 1909-1937. (c) DePuy, C. H.;
Bierbaum, V. M. J . Am. Chem. Soc. 1981, 103, 5034-5038.
(14) Henig, G.; Schulz, M.; Werner, H. Chem. Commun. 1997, 2349-
2350.

Os(II) Mesitylene Complexes with Phosphine Ligands
Organometallics, Vol. 18, No. 7, 1999 1189
Sch em e 6a
a
E ) CO2Me.
dominating species. This ring-substituted derivative of
20 formally results from the addition of the C-H bond
of the phosphino ester enolate across the CdN bond of
the substrate. Insertion reactions of this type are not
without precedent and have been studied in detail,
particularly by Braunstein, Matt, and their co-workers.4
Characteristic spectroscopic features of 21 are the N-H
stretching frequency at 3405 cm-1 in the IR and the
signal for the N-H proton at δ 9.13 in the 1H NMR
spectrum.
compared to a normal CdC bond, the distance C2-O1
(1.28(1) Å) lies between that of a C-O single and a Cd
O double bond, indicating some electron delocalization
within the enolate ligand. In analogy to 9 and 11, the
Os-C24 to Os-C29 bond lengths differ by ca. 0.14 Å
(Table 3), for which both steric and electronic effects
could be responsible.
The reaction of 22 with C2(CO2Me)2 (DMAD) in the
presence of 1 equiv of AgPF6 in CH2Cl2 led to the
replacement of the chloride by the alkyne and gave the
Not only phenyl isocyanate but also diphenylketene
forms the 1:1 adduct 22 with the enolate complex 20. If
the reaction is carried out in hexane/dichloromethane
(3:1) and the reaction mixture worked up by column
chromatography with basic Al2O3, the product is isolated
in 63% yield. The composition of the pale yellow, only
moderately air- and moisture-sensitive solid was sub-
stantiated not only by elemental analysis and spectro-
scopic techniques but also by X-ray crystallography. The
presence of the uncoordinated CO2Me group is indicated
by the CdO absorption in the IR spectrum at 1671 cm-1
and the 13C NMR resonance (singlet) at δ 194.6. The
signal for the C-O enolate carbon atom appears at δ
182.3 and is split into a doublet due to P-C coupling.
The result of the single-crystal X-ray structure analy-
sis of 22 is shown in Figure 3. The ORTEP diagram
(Figure 3) reveals that the molecule possesses a similar
piano-stool configuration as the cationic complex 11 with
bond angles between the three “legs” of 88.6(1)° (P-Os-
Cl), 83.8(2)° (O1-Os-Cl), and 79.6(2)° (O1-Os-P). The
five-membered phosphanyl enolate-osmium unit is
almost planar, with the carbon atoms C3 and C5 of the
substituents lying in the ring plane. While the bond
length C1-C2 (1.36(1) Å) is only slightly elongated
F igu r e 3. ORTEP drawing of 22.

1190 Organometallics, Vol. 18, No. 7, 1999
Werner et al.
Ta ble 3. Selected Bon d Dista n ces a n d An gles w ith
Esd ’s for Com p ou n d 22
Ta ble 4. Selected Bon d Dista n ces a n d An gles w ith
Esd ’s for Com p ou n d 23
Bond Distances (Å)
Bond Distances (Å)
Os-Cl
2.389(3)
2.341(3)
2.074(7)
2.29(1)
2.19(1)
2.21(1)
2.17(1)
2.15(1)
Os-C29
O1-C2
C1-C2
C2-C5
P-C1
C1-C3
C3-O2
C3-O3
2.23(1)
1.28(1)
1.36(1)
1.55(1)
1.79(1)
1.47(2)
1.21(1)
1.36(1)
Os-O1
Os-P1
2.052(4)
2.374(2)
2.095(7)
2.147(7)
2.274(7)
2.350(7)
2.316(7)
2.246(7)
2.253(8)
2.324(8)
1.803(6)
O1-C1
C1-C2
C1-C7
C2-C5
O2-C5
O3-C5
O3-C6
C3-C4
C3-C30
C4-C40
1.304(7)
1.372(9)
1.542(8)
1.465(9)
1.188(8)
1.341(8)
1.438(9)
1.243(9)
1.48(1)
Os-P
Os-O1
Os-C24
Os-C25
Os-C26
Os-C27
Os-C28
Os-C3
Os-C4
Os-C10
Os-C11
Os-C12
Os-C13
Os-C14
Os-C15
P1-C2
Bond Angles (deg)
88.6(1)
83.8(2)
1.47(1)
Cl-Os-P
C2-C1-C3
123.0(9)
113.7(8)
123.3(8)
129(1)
110(1)
121(1)
Cl-Os-O1
P-Os-O1
Os-O1-C2
Os-P-C1
O1-C2-C1
O1-C2-C5
C1-C2-C5
P-C1-C2
79.6(2)
P-C1-C3
Bond Angles (deg)
122.8(6)
100.7(3)
122.8(9)
113.3(9)
123.9(9)
C1-C3-O2
C1-C3-O3
O2-C3-O3
C3-O3-C4
P1-Os-O1
P1-Os-C3
P1-Os-C4
O1-Os-C3
O1-Os-C4
C3-Os-C4
Os-C3-C4
Os-C4-C3
Os-O1-C1
Os-P1-C2
P1-C2-C1
79.0(1)
92.6(2)
88.8(2)
84.7(2)
117.1(2)
34.1(2)
75.3(5)
70.6(5)
123.5(4)
100.1(2)
113.1(5)
P1-C2-C5
O1-C1-C2
O1-C1-C7
C2-C1-C7
C1-C2-C5
O2-C5-C2
O2-C5-O3
C2-C5-O3
C5-O3-C6
C3-C4-C40
C4-C3-C30
124.3(5)
122.0(6)
113.8(5)
124.1(6)
122.5(6)
127.6(7)
121.5(7)
110.9(6)
116.1(6)
147.7(8)
146.2(7)
116(1)
bond angles of 146.2(7) and 147.7(8)°, respectively. A
similar degree of bending has also been found in other
(alkyne)osmium complexes.15 The distances from the
metal to the mesitylene ring carbon atoms in 23 are
approximately 0.08 Å longer than in 22, which could
be due to the decrease in back-donation by increasing
the positive charge at the metal center.
In the presence of water in acetone solution, hydroly-
sis of the enolate function of compound 20 takes place
and the phosphanyl acetate complex 24 (see Scheme 6)
is formed in 92% yield. A related metal-assisted trans-
formation of a phosphanyl enolate to a corresponding
acetate was recently observed by us16 as well as by
Braunstein et al.17 in the case of square-planar iridium
and palladium derivatives. The IR and NMR data of 23
(a pale yellow, almost air-stable solid) are similar to
those of [(mes)RuCl(κ2(P,O)-Ph2PCH2CO2)], which was
obtained by acid hydrolysis of [(mes)RuCl2(κ1(P)-Ph2-
PCH2CO2Me)].18 It should be mentioned that upon
treatment of 20 with HCl, instead of cleavage of the
O-CH3 bond of the enolate moiety protonation of the
PCHd carbon atom occurs and the dichloroosmium(II)
complex 14 is generated quantitatively.
F igu r e 4. ORTEP drawing of 23.
cationic complex 23 as an orange solid in almost
quantitative yield. The aim of this experiment was to
find out whether compound 22 behaves similarly to
phosphanyl keto enolates of nickel, palladium, and
platinum, which react with DMAD by insertion to form
a new C-C bond.4b However, with 22 as the starting
material such a coupling process does not occur.
The coordination of the acetylene derivative in 23 via
the triple bond, as indicated by the appearance of the
ν(CtC) stretching vibration at 1863 cm-1 in the IR and
the two signals for the alkyne carbon atoms at δ 95.9
and 95.4 in the 13C NMR spectrum, was confirmed by
an X-ray structure analysis. As the ORTEP plot (Figure
4) reveals, the steric requirements around the osmium
are quite severe, and this may explain why the DMAD
ligand is not symmetrically coordinated to the metal
center. The difference in the bond lengths Os-C3 and
Os-C4 is ca. 0.05 Å (Table 4). The DMAD backbone
C30-C3-C4-C40 is not linear, possessing C-C-C
Con clu sion s
The work presented in this paper has shown that
bulky, functionalized phosphines of the general compo-
sition iPr2P(CH2)nY with n ) 1-3 and Y ) OMe, NMe2,
CO2Me behave in half-sandwich-type (arene)osmium-
(II) complexes as monodentate (P-bonded) as well as
bidentate ligands. In contrast to ruthenium for which
numerous compounds with coordinated phosphanyl
derivatives R2P(CH2)nY (R mainly phenyl) are known,3,18
related osmium complexes are quite rare and up to now
have been mainly described from our laboratory.7,11 Not
(15) (a) Ball, R. G.; Burke, M. R.; Takats, J . Organometallics 1987,
6, 1918-1924. (b) Marinelli, G.; Streib, W. E.; Huffman, J . C.; Caulton,
K. G.; Gagne´, M. R.; Takats, J .; Dartiguenave, M.; Chardon, C.;
J ackson, S. A.; Eisenstein, O. Polyhedron 1990, 9, 1867-1881. (c)
Espuelas, J .; Esteruelas, M. A.; Lahoz, F. J .; Lopez, A. M.; Oro, L. A.;
Valero, C. J . Organomet. Chem. 1994, 468, 223-228.
(16) Steinert, P.; Werner, H. Chem. Ber. 1997, 130, 1591-1603.
(17) Braunstein, P.; Matt, D.; Nobel, D.; Bouaoud, S.-E.; Grandjean,
D. J . Organomet. Chem. 1986, 301, 401-410.
(18) Demerseman, B.; Renouard, C.; Le Lagadec, R.; Gonzalez, M.;
Chrochet, P.; Dixneuf, P. H. J . Organomet. Chem. 1994, 471, 229-
239.

Os(II) Mesitylene Complexes with Phosphine Ligands
Organometallics, Vol. 18, No. 7, 1999 1191
g of Hg, 9.97 mmol) in 5 mL of THF and 0.2 mL of ethanol.
The reaction mixture was rigorously stirred for 2 h at room
temperature. After the solution and the solid material became
separated, the solution was decanted and the solid was washed
twice with 10 mL portions of THF. The combined liquid phases
were brought to dryness in vacuo, and the residue was
extracted with 30 mL of benzene. The solvent was removed
from the extract, and the residue was recrystallized from CH2-
unexpectedly, the state of the art is that the functional
group Y of the substituted phosphines iPr2P(CH2)nY
form stronger bonds to Os than to Ru with the conse-
quence that these phosphines are not typical hemilabile
chelating systems if bonded to osmium. The advantage
of forming stronger chelate bonds is that it is easier to
transform the original phosphanyl compounds into
phosphanyl enolate or phosphanylmethanide deriva-
tives and these, as it was illustrated by several examples
reported here, are useful starting materials for further
synthesis.
1
Cl2/hexane to give a yellow solid. The H and 31P NMR spectra
confirmed that the solid consists of a 2:1 mixture of compounds
4 and 6, which could not be separated either by column
chromatography or by fractional crystallization. 4: 1H NMR
(400 MHz, C6D6) δ 4.64 (s, 3H, C6H3Me3), 2.83, 2.55 (both m,
2H, CH2NMe2), 2.38 (m, 1H, PCHCH3), 2.26 (m, 1H, PCH2),
2.17 (s, 6H, NMe2), 2.09 (s, 9H, C6H3Me3), 1.95 (m, 1H,
PCHCH3), 1.86 (m, 1H, PCH2), 1.19 [dd, J (PH) ) 14.1, J (HH)
) 7.2 Hz, 3H, PCHCH3], 1.06 [dd, J (PH) ) 12.7, J (HH) ) 7.4
Hz, 3H, PCHCH3], 1.04 [dd, J (PH) ) 14.9, J (HH) ) 7.4 Hz,
3H, PCHCH3], 1.01 [dd, J (PH) ) 12.7, J (HH) ) 7.1 Hz, 3H,
PCHCH3], -9.08 [d, J (PH) ) 44.2 Hz, 1H, OsH]; 31P NMR
(162.0 MHz, C6D6) δ 13.1 [s; d in off-resonance, J (187Os31P) )
266.2 Hz]. 6: 1H NMR (400 MHz, C6D6) δ 4.83 (s, 3H, C6H3-
Me3), 2.63 (m, 2H, CH2NMe2), 2.34 (s, 6H, NMe2), 2.14 (s, 9H,
C6H3Me3), 1.83 (m, 2H, PCH2), 1.64 (m, 2H, PCHCH3), 1.00,
0.99 (both m, 12H, PCHCH3), -12.15 [d, J (PH) ) 37.9 Hz, 2H,
OsH2]; 31P NMR (162.0 MHz, C6D6) δ 30.3 [s; t in off-resonance,
J (187Os31P) ) 267.9 Hz].
Exp er im en ta l Section
Gen er a l Con sid er a tion s. All experiments were carried out
under an atmosphere of argon by Schlenk techniques. Solvents
were dried by known procedures and distilled before use. The
starting materials 1,19 8,7 17,7 and 18,7 as well as the
functionalized phosphine ligands iPr2P(CH2)nNMe2,20 were
prepared as described in the literature.
P h ysica l Mea su r em en ts. NMR spectra were recorded at
room temperature or at the temperature mentioned in the
appropriate procedure on Bruker AC 200 and Bruker AMX
400 instruments. Chemical shifts are expressed in ppm down-
field from SiMe4 (1H and 13C) and (85%) H3PO4 (31P). Abbrevia-
tions used: s, singlet; d, doublet; q, quartet; sept, septet; m,
multiplet; br, broadened signal. Coupling constants J are given
in hertz. The conductivity Λ was measured in nitromethane
with a Schott Konduktometer CG 851 instrument, and melting
and decomposition points were determined by DTA.
P r ep a r a tion of [(m es)OsCl2(K1(P )-iP r 2P CH2CH2NMe2)]
(2). A suspension of 1 (242 mg, 0.32 mmol for n ) 2) in 30 mL
of CH2Cl2 was treated dropwise with iPr2PCH2CH2NMe2 (310
µL, 1.47 mmol) and stirred for 2.5 h at room temperature. The
solution was filtered, the solid residue on the filter disk was
washed three times with 10 mL portions of CH2Cl2, and the
combined filtrates were concentrated to ca. 6-8 mL in vacuo.
Upon addition of 30 mL of hexane an orange solid precipitated,
which was separated from the mother liquor, washed with 5
mL of hexane, and dried: yield 317 mg (87%); mp 136 °C dec.
1H NMR (400 MHz, C6D6): δ 4.85 (s, 3H, C6H3Me3), 2.73 (m,
2H, CH2NMe2), 2.58 (m, 2H, PCH2), 2.31 (m, 2H, PCHCH3),
2.14 (s, 6H, NMe2), 1.94 (s, 9H, C6H3Me3), 1.14 [dd, J (PH) )
13.2, J (HH) ) 7.0 Hz, 6H, PCHCH3], 1.08 [dd, J (PH) ) 14.4,
J (HH) ) 7.0 Hz, 6H, PCHCH3]. 31P NMR (162.0 MHz, C6D6):
δ -9.5 [s, J (187Os31P) ) 278.0 Hz]. Anal. Calcd for C19H36Cl2-
NOsP (570.6): C, 40.00; H, 6.36; N, 2.45. Found: C, 40.32; H,
6.59; N, 2.34.
P r ep a r a tion of [(m es)OsCl2(K1(P )-iP r 2P CH2CH2CH2N-
Me2)] (3). This compound was prepared as described for 2,
using 1 (340 mg, 0.45 mmol for n ) 2) and iPr2PCH2CH2CH2-
NMe2 (400 µL, 1.58 mmol) as starting materials: orange solid;
yield 493 mg (94%); mp 144 °C dec. 1H NMR (400 MHz,
C6D6): δ 4.90 (s, 3H, C6H3Me3), 2.40 (m, 2H, PCH2), 2.27 (m,
2H, PCHCH3), 2.15 [t, J (HH) ) 7.0 Hz, 2H, CH2NMe2], 2.08
(s, 6H, NMe2), 1.97 (s, 9H, C6H3Me3), 1.86 (m, 2H, CH2CH2-
NMe2), 1.11 [dd, J (PH) ) 12.6, J (HH) ) 6.9 Hz, 6H, PCHCH3],
1.10 [dd, J (PH) ) 14.1, J (HH) ) 7.2 Hz, 6H, PCHCH3]. 31P
NMR (162.0 MHz, C6D6): δ -9.4 [s, J (187Os31P) ) 277.3 Hz].
Anal. Calcd for C20H38Cl2NOsP (584.6): C, 41.09; H, 6.55; N,
2.40. Found: C, 41.51; H, 6.83; N, 2.18.
P r ep a r a tion of [(m es)OsHCl(K1(P )-iP r 2P CH2CH2CH2-
NMe2)] (5) an d [(m es)OsH2{K1(P )-iP r 2P CH2CH2CH2NMe2)]
(7). This was carried out as described for 4/6, from 3 (103 mg,
0.18 mmol) and magnesium amalgam (30 mg of Mg, 1.23
mmol; 2.0 g of Hg, 9.97 mmol) in THF/ethanol. A yellow solid
was obtained, the NMR spectra of which revealed that it is a
10:1 mixture of compounds 5 and 7. After column chromatog-
raphy (basic Al2O3, activity grade III, height of column 5 cm)
a product was isolated which still contained small amounts of
7. 5: 1H NMR (400 MHz, C6D6) δ 4.64 (s, 3H, C6H3Me3), 2.37,
2.29, 2.25, 2.23, 1.95 (all m, 6H, PCH2, CH2NMe2 and PCHCH3),
2.12 (s, 6H, NMe2), 2.09 (s, 9H, C6H3Me3), 1.76, 1.64 (both m,
2H, PCH2CH2), 1.20 [dd, J (PH) ) 14.0, J (HH) ) 7.1 Hz, 3H,
PCHCH3], 1.06 [dd, J (PH) ) 12.7, J (HH) ) 7.1 Hz, 3H,
PCHCH3], 1.01, 0.99 (both m, 6H, PCHCH3), -9.01 [d, J (PH)
) 43.2 Hz, 1H, OsH]; 31P NMR (C6D6, 162.0 MHz) δ 14.7 [s; d
in off-resonance, J (187Os31P) ) 266.2 Hz]. Typical data for 7:
1H NMR (400 MHz, C6D6) δ 4.84 (s, 3H, C6H3Me3), 2.34 (s,
6H, NMe2), 2.11 (s, 9H, C6H3Me3), -12.11 [d, J (PH) ) 38.2
Hz, 2H, OsH2]; 31P NMR (162.0 MHz, C6D6) δ 31.9 [s; t in off-
resonance].
P r ep a r a tion of [(m es)OsHCl(K1(P )-iP r 2P CH2CH2OMe)]
(9). This compound was prepared as described for the mixture
of 4/6, from 8 (141 mg, 0.25 mmol) and magnesium amalgam
(30 mg of Mg, 1.23 mmol; 2.0 g of Hg, 9.97 mmol) in THF/
ethanol: yellow solid; yield 117 mg (88%); mp 132 °C dec; MS
(70 eV) m/z 524 (M+). IR (KBr): ν(OsH) 2040, ν(C-O) 1103
cm-1. 1H NMR (400 MHz, C6D6): δ 4.62 (s, 3H, C6H3Me3), 3.90,
3.72 (both m, 2H, CH2OMe), 3.18 (s, 3H, OCH3), 2.49 (m, 1H,
PCH2), 2.26 (m, 1H, PCHCH3), 2.07 (s, 9H, C6H3Me3), 1.98 (m,
1H, PCH2), 1.91 (m, 1H, PCHCH3), 1.17 [dd, J (PH) ) 14.3,
J (HH) ) 7.0 Hz, 3H, PCHCH3], 1.02 [dd, J (PH) ) 13.2, J (HH)
) 7.0 Hz, 3H, PCHCH3], 0.96 [dd, J (PH) ) 14.4, J (HH) ) 7.0
Hz, 3H, PCHCH3], 0.95 [dd, J (PH) ) 13.1, J (HH) ) 7.0 Hz,
3H, PCHCH3], -9.18 [d, J (PH) ) 44.4 Hz, 1H, OsH]. 31P NMR
(162.0 MHz, C6D6): δ 12.7 [s; d in off-resonance, J (187Os31P) )
267.0 Hz]. Anal. Calcd for C18H34ClOOsP (523.1): C, 41.33;
H, 6.55. Found: C, 41.74; H, 6.71.
P r ep a r a tion of [(m es)OsHCl(K1(P )-iP r 2P CH2CH2NMe2)]
(4) a n d [(m es)OsH2(K1(P )-iP r 2P CH2CH2NMe2)] (6). A solu-
tion of 2 (92 mg, 0.16 mmol) in 7 mL of THF was added to a
mixture of magnesium amalgam (30 mg of Mg, 1.23 mmol; 2.0
P r ep a r a tion of [(m es)OsH2(K1(P )-iP r 2P CH2CH2OMe)]
(10). A solution of 9 (110 mg, 0.21 mmol) in 7 mL of THF was
added to a mixture of magnesium amalgam (100 mg of Mg,
4.11 mmol; 2.0 g of Hg, 9.97 mmol) in 5 mL of THF and 0.5
mL of ethanol. After the reaction mixture was rigorously
stirred for 2 h at room temperature, it was worked up as
(19) Stahl, S.; Werner, H. Organometallics 1990, 9, 1876-1881.
(20) (a) Werner, H.; Hampp, A.; Peters, K.; Walz, L.; von Schnering,
H. G.; Z. Naturforsch., B: Anorg. Chem., Org. Chem. 1990, 45, 1548-
1558. (b) Werner, H.; Hampp, A.; Windmu¨ller, B. J . Organomet. Chem.
1992, 435, 169-183.

1192 Organometallics, Vol. 18, No. 7, 1999
Werner et al.
described for 4/6. The crude product (yellow solid) was dis-
solved in 3 mL of benzene, and the solution was chromato-
graphed on Al2O3 (basic, activity grade III, column length 5
cm). With benzene, a yellow fraction was eluted which
contained unreacted 9 (32 mg; 29%). A second fraction was
eluted with CH2Cl2, from which the white solid 10 was
isolated: yield 60 mg (58%); mp 74 °C; MS (70 eV) m/z 488
(M+). IR (KBr): ν(OsH) 2042 cm-1. 1H NMR (400 MHz, C6D6):
δ 4.82 (s, 3H, C6H3Me3), 3.77 (m, 2H, CH2OMe), 3.16 (s, 3H,
OCH3), 2.32 (s, 9H, C6H3Me3), 2.03 (m, 2H, PCH2), 1.61 (m,
2H, PCHCH3), 0.98 [dd, J (PH) ) 14.8, J (HH) ) 7.0 Hz, 6H,
PCHCH3], 0.95 [dd, J (PH) ) 13.6, J (HH) ) 7.0 Hz, 6H,
PCHCH3], -12.20 [d, J (PH) ) 36.0 Hz, 2H, OsH2]. 31P NMR
(162.0 MHz, C6D6): δ 27.5 [s; t in off-resonance]. Anal. Calcd
for C18H35OOsP (488.7): C, 44.24; H, 7.22. Found: C, 44.28;
H, 8.07.
Rea ction of Com p ou n d 8 w ith Na BH4. A suspension of
8 (200 mg, 0.36 mmol) in 10 mL of benzene was treated first
with an excess of NaBH4 (ca. 200 mg) and then dropwise with
1 mL of methanol. After the reaction mixture was stirred for
1 h at room temperature, the solvent was removed and the
residue was extracted with 20 mL of benzene. The extract was
worked up as described for 10. The chromatographic separa-
tion afforded both 9 (84 mg) and 10 (82 mg) in, respectively,
45% and 47% yield.
144 °C dec; Λ ) 69 cm2 Ω-1 mol-1. IR (KBr): ν(OsH) 2061,
ν(C-O) 1037 cm-1. 1H NMR (400 MHz, CD2Cl2): δ 5.26 (s, 3H,
C6H3Me3), 3.85 (s, 3H, OCH3), 3.67, 3.26 (both m, 2H, CH2-
OMe), 2.40 (s, 9H, C6H3Me3), 2.28 (m, 2H, PCH2 and PCHCH3),
1.66 (m, 1H, PCHCH3), 1.43 (m, 1H, PCH2), 1.34 [dd, J (PH) )
15.5, J (HH) ) 6.4 Hz, 3H, PCHCH3], 1.29 [dd, J (PH) ) 11.4,
J (HH) ) 7.6 Hz, 3H, PCHCH3], 1.00 [dd, J (PH) ) 15.3, J (HH)
) 7.6 Hz, 3H, PCHCH3], 0.90 [dd, J (PH) ) 17.8, J (HH) ) 7.6
Hz, 3H, PCHCH3], -8.29 [d, J (PH) ) 36.9 Hz, 1H, OsH]. 31P
NMR (162.0 MHz, CD2Cl2): δ 55.4 [s; d in off-resonance,
J (187Os31P) ) 274.7 Hz, PiPr2], -144.4 [sept, J (PF) ) 710.6
Hz, PF6-]. Anal. Calcd for C18H34F6OOsP2: C, 34.18; H, 5.42.
Found: C, 33.93; H, 5.34.
Rea ction of [(m es)OsCl(K2(P ,O)-iP r 2P CH2CH2OMe)]-
P F 6 (12) w ith CO. A stream of CO was passed through a
solution of 12 (73 mg, 0.11 mmol) in 2 mL of CH2Cl2 for 1 min
at room temperature. This was repeated four times in 1 h. The
solvent was removed, and the remaining yellow solid was
washed repeatedly with 5 mL portions of ether and dried. The
1H and 31P NMR spectra revealed that besides [(mes)OsCl-
(CO)(κ1(P)-iPr2PCH2CH2OMe)]PF6 (14) small amounts of 12
were still present, which could not removed by fractional
crystallization or other separation techniques. Data for 14: IR
1
(CH2Cl2) ν(CO) 1990; H NMR (200 MHz, CD2Cl2) δ 6.02 (s,
3H, C6H3Me3), 3.65 (m, 2H, CH2OMe), 3.37 (s, 3H, OCH3), 2.61
(s, 9H, C6H3Me3), 2.49 (m, 4H, PCH2 and PCHCH3), 1.53 (m,
3H, PCHCH3), 1.38 (m, 6H, PCHCH3), 1.27 (m, 3H, PCHCH3);
13C NMR (50.3 MHz, CD2Cl2) δ 189.2 [d, J (PC) ) 22.0 Hz, CO],
105.9 [d, J (PC) ) 1.2 Hz, CMe of mes], 82.2 (s, CH of mes),
67.8 (s, CH2OMe), 59.0 (s, OCH3), 26.2 [d, J (PC) ) 29.8 Hz,
PCHCH3], 25.8 [d, J (PC) ) 31.5 Hz, PCHCH3], 22.0 [d, J (PC)
) 31.0 Hz, PCH2], 19.4, 19.0, 18.8 (all s, PCHCH3), 18.6 (s,
CH3 of mes), 18.4 [d, J (PC) ) 2.2 Hz, PCHCH3]; 31P NMR (81.0
MHz, CD2Cl2) δ 10.9 (s, PiPr2), -143.9 [sept, J (PF) ) 710.7
Hz, PF6-].
P r epar ation of [(m es)OsCl(K2(P ,N)-iP r 2P CH2CH2NMe2)]-
P F 6 (11). A solution of 2 (178 mg, 0.31 mmol) in 15 mL of
CH2Cl2 was treated with a solution of AgPF6 (79 mg, 0.31
mmol) in 10 mL of CH2Cl2 and stirred for 45 min at room
temperature. The reaction mixture was filtered with Celite,
and the filtrate was brought to dryness in vacuo. The residue
was repeatedly washed with ether and then dissolved in 2 mL
of CH2Cl2, and the solution was layered with 10 mL of hexane.
Orange crystals slowly precipitated which (after 5 days) were
filtered, washed twice with ether, and dried: yield 158 mg
(52%); mp 157 °C dec; Λ ) 75 cm2 Ω-1 mol-1 1H NMR (400
.
P r ep a r a tion of [(m es)OsCl(CNMe)(K1(P )-iP r 2P CH2CH2-
OMe)]P F 6 (15). A solution of 12 (180 mg, 0.27 mmol) in 10
mL of CH2Cl2 was treated with methyl isocyanide (15 mg, 0.37
mmol) and stirred for 30 min at room temperature. After
removal of the solvent in vacuo, a pale yellow solid was
isolated, which was washed repeatedly with 5 mL portions of
ether and dried: yield 184 mg (96%); mp 144 °C dec; Λ ) 74
MHz, CDCl3): δ 5.97 (s, 3H, C6H3Me3), 3.09 (m, 2H, CH2NMe2),
3.05 (s, 6H, NMe2), 2.73, 2.57 (both m, 2H, PCHCH3), 2.38 (s,
9H, C6H3Me3), 1.97, 1.87 (both m, 2H, PCH2), 1.44 [dd, J (PH)
) 15.0, J (HH) ) 7.2 Hz, 3H, PCHCH3], 1.35, 1.33, 1.31 (all m,
9H, PCHCH3). 13C NMR (100.6 MHz, CDCl3): δ 93.2 [d, J (PC)
) 2.1 Hz, CMe of mes], 78.6 [d, J (PC) ) 1.9 Hz, CH of mes],
65.2 [d, J (PC) ) 2.3 Hz, CH2NMe2], 59.6, 57.3 (both s, NMe2),
26.4 [d, J (PC) ) 29.5 Hz, PCHCH3], 24.1 [d, J (PC) ) 30.5 Hz,
PCHCH3], 22.1 [d, J (PC) ) 27.1 Hz, PCH2], 19.5, 19.0, 18.5,
18.3 (all s, PCHCH3), 18.4 (s, CH3 of mes). 31P NMR (162.0
MHz, CDCl3): δ 27.3 (s, PiPr2), -144.2 [sept, J (PF) ) 712.7
Hz, PF6-]. Anal. Calcd for C19H36ClF6NOsP2 (680.1): C, 33.56;
H, 5.34; N, 2.06; Os, 27.97. Found: C, 33.43; H, 5.32; N, 2.00;
Os, 27.80.
cm2 Ω-1 mol-1. IR (CH2Cl2): ν(CtN) 2183, ν(C-O) 1101 cm-1
.
1H NMR (400 MHz, CD2Cl2): δ 5.62 (s, 3H, C6H3Me3), 3.85 [d,
J (PH) ) 1.2 Hz, 3H, CNCH3], 3.60 (m, 2H, CH2OMe), 3.32 (s,
3H, OCH3), 2.49 (m, 2H, PCH2), 2.42 (s, 9H, C6H3Me3), 2.31
(m, 2H, PCHCH3), 1.26 (m, 3H, PCHCH3), 1.24 (m, 6H,
PCHCH3), 1.19 (m, 3H, PCHCH3). 13C NMR (50.3 MHz, CD2-
Cl2): δ 171.2 (s, CNMe), 107.0 [d, J (PC) ) 1.5 Hz, CMe of mes],
84.6 (s, CH of mes), 68.4 (s, CH2OMe), 58.7 (s, OCH3), 31.0 (s,
CNCH3), 27.4 [d, J (PC) ) 30.2 Hz, PCHCH3], 26.6 [d, J (PC)
) 32.0 Hz, PCHCH3], 22.5 [d, J (PC) ) 31.4 Hz, PCH2], 19.5,
19.0 (both s, PCHCH3), 19.1 (s, CH3 of mes), 18.6 [d, J (PC) )
2.4 Hz, PCHCH3]. 31P NMR (162.0 MHz, CD2Cl2): δ 3.4 (s,
PiPr2), -144.3 [sept, J (PF) ) 710.6 Hz, PF6-]. Anal. Calcd for
C20H36ClF6NOOsP2 (708.1): C, 33.92; H, 5.12; N, 1.98; Os,
26.86. Found: C, 33.93; H, 5.16; N, 1.92; Os, 26.65.
P r ep a r a tion of[(m es)OsCl(K2(P ,O)-iP r 2P CH2CH2OMe)]-
P F 6 (12). This compound was prepared as described for 11,
from 8 (524 mg, 0.94 mmol) and AgPF6 (237 mg, 0.94 mmol)
as starting materials: pale yellow solid; yield 596 mg (95%);
mp 134 °C dec; Λ ) 68 cm2 Ω-1 mol-1 1H NMR (400 MHz,
.
CDCl3): δ 5.75 (s, 3H, C6H3Me3), 4.01 (s, 3H, OCH3), 3.57, 3.28
(both m, 2H, CH2OMe), 2.81, 2.64 (both m, 2H, PCH2), 2.28
(s, 9H, C6H3Me3), 1.74, 1.70 (both m, 2H, PCHCH3), 1.33, 1.25
(both m, 12H, PCHCH3). 13C NMR (100.6 MHz, CDCl3): δ 92.9
[d, J (PC) ) 2.0 Hz, CMe of mes], 78.0 [d, J (PC) ) 2.0 Hz, CH
of mes], 77.1 [d, J (PC) ) 3.0 Hz, CH2OMe], 71.5 (s, OCH3),
26.7 [d, J (PC) ) 30.5 Hz, PCHCH3], 24.4 [d, J (PC) ) 31.5 Hz,
PCHCH3], 22.4 [d, J (PC) ) 27.5 Hz, PCH2], 19.3, 18.8, 18.5,
18.3 (all s, PCHCH3), 18.7 (s, CH3 of mes). 31P NMR (162.0
MHz, CDCl3): δ 34.5 [s, J (187Os31P) ) 287.7 Hz, PiPr2], -144.2
[sept, J (PF) ) 712.8 Hz, PF6-]. Anal. Calcd for C18H33ClF6-
OOsP2 (667.0): C, 32.41; H, 4.99. Found: C, 32.32; H, 4.77.
P r ep a r a tion of [(m es)OsH(K2(P ,O)-iP r 2P CH2CH2OMe)]-
P F 6 (13). This compound was prepared as described for 11,
from 9 (65 mg, 0.12 mmol) and AgPF6 (30 mg, 0.12 mmol) as
starting materials: pale yellow solid; yield 70 mg (92%); mp
P r ep a r a tion of [(m es)OsH(OMe)(iP r 2P CHdCH2)] (16).
A solution of 13 (70 mg, 0.11 mmol) in 15 mL of THF was
treated with KOtBu (120 mg, 1.07 mmol) and stirred for 2 h
at room temperature. The solvent was removed, and the
remaining oily residue was extracted with 20 mL of hexane/
benzene (2:1). The extract was brought to dryness in vacuo,
and the remaining pale yellow oil was washed twice with 2
mL portions of hexane (0 °C): yield 39 mg (72%). IR (hexane):
ν(OsH) 2048, ν(CdC) 1567 cm-1. 1H NMR (400 MHz, C6D6): δ
6.32 [m; in 1H{31P} dd, J (H1H3) ) 18.9, J (H1H2) ) 12.8 Hz,
1H, PCH1dCH2], 5.59 [m; dd in 1H{31P}, J (H1H2) ) 12.8,
J (H2H3) ) 2.0 Hz, 1H, H2], 5.44 [m; dd in 1H{31P}, J (H1H3) )
18.9, J (H2H3) ) 2.0 Hz, 1H, H3], 4.69 (s, 3H, C6H3Me3), 4.05
(s, 3H, OCH3), 2.36, 1.94 (both m, 2H, PCHCH3), 2.08 (s, 9H,

Os(II) Mesitylene Complexes with Phosphine Ligands
Organometallics, Vol. 18, No. 7, 1999 1193
C6H3Me3), 1.22, 1.09 [both dd, J (PH) ) 14.9, J (HH) ) 7.0 Hz,
6H, PCHCH3], 1.00, 0.91 [both dd, J (PH) ) 13.5, J (HH) ) 6.8
Hz, 6H, PCHCH3], -8.55 [d, J (PH) ) 43.2 Hz, 1H, OsH]. 13C
NMR (100.6 MHz, C6D6): δ 133.0 [d, J (PC) ) 37.6 Hz, PCHd
CH2], 127.0 [d, J (PC) ) 2.0 Hz, PCHdCH2], 93.6 [d, J (PC) )
3.0 Hz, CMe of mes], 74.1 [d, J (PC) ) 3.1 Hz, CH of mes],
71.6 [d, J (PC) ) 3.1 Hz, OCH3], 24.7 [d, J (PC) ) 32.6 Hz,
PCHCH3], 21.4 [d, J (PC) ) 30.5 Hz, PCHCH3], 20.1 (s, CH3 of
mes), 18.6, 18.4 [both d, J (PC) ) 2.3 Hz, PCHCH3], 18.2, 18.1
(both s, PCHCH3). 31P NMR (162.0 MHz, C6D6): δ 18.3 [s, d
solid was obtained: yield 73 mg (80%); mp 90 °C dec; MS (70
eV) m/z 536 (M+). IR (CH2Cl2): ν(CdO + CdC) 1536 cm-1. 1H
NMR (200 MHz, C6D6): δ 4.69 (s, 3H, C6H3Me3), 3.57 (s, 3H,
OMe), 3.48 [d, J (PH) ) 1.4 Hz, 1H, PCHCO2], 2.51, 2.02 (both
m, 2H, PCHCH3), 1.91 (s, 9H, C6H3Me3), 1.32, 1.24, 1.11, 0.92
(all m, 12H, PCHCH3). 13C NMR (100.6 MHz, C6D6): δ 184.4
[d, J (PC) ) 27.0 Hz, CO2], 93.3 [d, J (PC) ) 2.3 Hz, CMe of
mes], 72.6 [d, J (PC) ) 3.5 Hz, CH of mes], 53.7 [d, J (PC) )
1.7 Hz, OCH3], 45.6 [d, J (PC) ) 73.9 Hz, PCHCO2], 26.1 [d,
J (PC) ) 30.5 Hz, PCHCH3], 25.6 [d, J (PC) ) 27.0 Hz,
PCHCH3], 20.2 [d, J (PC) ) 2.3 Hz, PCHCH3], 19.9 [d, J (PC)
) 3.5 Hz, PCHCH3], 19.4 [d, J (PC) ) 2.3 Hz, PCHCH3], 19.1
[d, J (PC) ) 1.2 Hz, PCHCH3], 18.8 (s, CH3 of mes). 31P NMR
(C6D6, 81.0 MHz): δ 20.8 (s). Anal. Calcd for C18H30ClO2OsP
(535.1): C, 40.41; H, 5.64. Found: C, 40.64; H, 5.64.
in off-resonance, J (187Os31P) ) 286.5 Hz]. Anal. Calcd for C18
33OOsP (486.6): C, 44.43; H, 6.83. Found: C, 44.65; H, 7.10.
P r epar ation of [(m es)OsCl{K2(P ,O)-iP r 2P CH2C(OMe)O}]-
-
H
P F 6 (19a ). This compound was prepared as described for 11,
from 17 (270 mg, 0.47 mmol) and AgPF6 (119 mg, 0.47 mmol)
as starting materials: pale yellow solid; yield 272 mg (85%);
mp 162 °C dec; Λ ) 82 cm2 Ω-1 mol-1. IR (KBr): ν(CdO) 1595
Rea ction of Com p ou n d 20 w ith P h NCO. A solution of
20 (82 mg, 0.15 mmol) in 10 mL of benzene was treated with
PhNCO (24 mg, 0.20 mmol) and stirred for 2 h at room
temperature. A gradual change of color from yellow to brown-
ish occurred. The solvent was removed, and the residue was
cm-1 1H NMR (400 MHz, CDCl3): δ 5.62 (s, 3H, C6H3Me3),
.
4.03 (s, 3H, OCH3), 3.14 [d, J (PH) ) 9.2 Hz, 2H, PCH2], 2.76,
2.65 (both m, 2H, PCHCH3), 2.34 (s, 9H, C6H3Me3), 1.33, 1.31
(both m, 6H, PCHCH3), 1.24 [dd, J (PH) ) 14.0, J (HH) ) 7.2
Hz, 3H, PCHCH3], 1.15 [dd, J (PH) ) 17.2, J (HH) ) 7.2 Hz,
3H, PCHCH3]. 13C NMR (50.3 MHz, CD2Cl2): δ 191.1 [d, J (PC)
) 8.3 Hz, CO2], 98.5 (s, CMe of mes), 72.7 [d, J (PC) ) 3.7 Hz,
CH of mes], 57.7 (s, OCH3), 29.5 [d, J (PC) ) 32.3 Hz, PCH2],
25.3 [d, J (PC) ) 26.8 Hz, PCHCH3], 24.3 [d, J (PC) ) 30.5 Hz,
PCHCH3], 19.2 (s, CH3 of mes), 18.8, 18.2, 16.9, 16.8 (all s,
PCHCH3).31P NMR (162.0 MHz, CDCl3): δ 33.9 [s, J (187Os31P)
) 265.9 Hz, PiPr2], -144.2 [sept, J (PF) ) 712.8 Hz, PF6-].
Anal. Calcd for C18H31ClF6O2OsP2 (681.0): C, 31.75; H, 4.59.
Found: C, 31.60; H, 4.26.
P r epar ation of [(m es)OsCl{K2(P ,O)-iP r 2P CH2C(OMe)O}]-
BF 4 (19b). A solution of 18 (85 mg, 0.16 mmol) in 10 mL of
ether was treated dropwise with a 0.1 M solution of HBF4 in
ether (1.6 mL, 0.16 mmol) at room temperature. A yellow solid
slowly precipitated. After the reaction mixture was stirred for
5 min, the solution was decanted, and the residue was washed
twice with 10 mL portions of ether and dried: pale yellow
microcrystalline solid; yield 95 mg (96%); mp 182 °C dec; Λ )
78 cm2 Ω-1 mol-1. The IR and NMR data of 19b-d are almost
identical with those of 19a . However, in the 1H NMR spectrum
of 19b (and similarly in the spectra of 19c and 19d ) the signals
for the PCH2 protons appear as AB parts of an ABX spectrum
with δ(HA) 3.23, δ(HB) 3.18, J (PHA) ) 9.5, J (PHB) ) 8.7, and
2J (HAHB) ) 17.5 Hz. Anal. Calcd for C18H31BClF4O2OsP
(622.9): C, 34.71; H, 5.02. Found: C, 34.18; H, 4.87.
1
washed repeatedly with 5 mL portions of hexane. The H and
31P NMR spectra of the yellow solid revealed that the crude
product consisted mainly (ca. 85%) of [(mes)OsCl{κ2(P,O)-iPr2-
PC(CONHPh)dC(OMe)O}] (21) and at least one other byprod-
uct which could not be separated by column chromatography
or fractional crystallization. Data for 21: IR (KBr) ν(NH) 3405,
ν(CdO) 1625, ν(CdO + CdC) 1590 cm-1; 1H NMR (400 MHz,
C6D6) δ 9.13 (s, 1H, NH), 8.06-6.79 (m, 5H, C6H5), 4.64 (s,
3H, C6H3Me3), 3.54 (s, 3H, OMe), 2.35, 2.20 (both m, 2H,
PCHCH3), 1.82 (s, 9H, C6H3Me3), 1.22 [dd, J (PH) ) 14.1, J (HH)
) 7.0 Hz, 3H, PCHCH3], 0.90 (m, 6H, PCHCH3), 0.85 (m, 3H,
PCHCH3); 31P NMR (162.0 MHz, C6D6) δ 28.8 (s).
P r ep a r a tion of [(m es)OsCl{K2(P ,O)-iP r 2P C(CO2Me)dC-
(CHP h 2)O}] (22). A solution of 20 (154 mg, 0.29 mmol) in 10
mL of hexane/CH2Cl2 (3:1) was treated with diphenylketene
(112 mg, 0.58 mmol) and stirred for 1 h at room temperature.
The solvent was removed, and the residue was washed twice
with 5 mL portions of hexane and then dissolved in 1 mL of
benzene. The solution was chromatographed on Al2O3 (basic,
activity grade III, height of column 5 cm). With benzene, a
yellow fraction was eluted which was brought to dryness in
vacuo. The residue was recrystallized from toluene/hexane (1:
5) to give a pale yellow crystalline solid: yield 132 mg (63%);
mp 107 °C dec; MS (70 eV) m/z 730 (M+). IR (KBr): ν(CdO)
1671, ν(CdO +CdC) 1597 cm-1. 1H NMR (400 MHz, C6D6): δ
7.66, 7.51, 7.22, 7.12, 7.04 (all m, 10H, C6H5), 4.52 (s, 3H, C6H3-
Me3), 3.57 (m, 1H, PCHCH3), 3.45 (s, 3H, OCH3), 2.25 (m, 1H,
PCHCH3), 2.10 (s, 1H, CHPh2), 1.70 (s, 9H, C6H3Me3), 1.62
[dd, J (PH) ) 12.8, J (HH) ) 7.1 Hz, 3H, PCHCH3], 1.56 [dd,
J (PH) ) 15.3, J (HH) ) 7.0 Hz, 3H, PCHCH3], 1.12 [dd, J (PH)
) 19.8, J (HH) ) 7.2 Hz, 3H, PCHCH3], 0.86 [dd, J (PH) ) 16.4,
J (HH) ) 7.0 Hz, 3H, PCHCH3]. 13C NMR (100.6 MHz, C6D6):
δ 194.6 (s, CO2), 182.3 [d, J (PC) ) 28.5 Hz, CO], 143.2, 142.8,
130.2, 130.0, 129.3, 128.5, 126.2, 126.0 (all s, C6H5), 93.2 [d,
J (PC) ) 2.4 Hz, CMe of mes], 82.6 [d, J (PC) ) 62.1 Hz, PCd
C], 74.3 [d, J (PC) ) 2.9 Hz, CH of mes], 59.8 [d, J (PC) ) 4.4
Hz, CHPh2], 52.8 (s, OCH3), 30.1 [d, J (PC) ) 32.3 Hz,
PCHCH3], 24.2 [d, J (PC) ) 38.3 Hz, PCHCH3], 20.9 [d, J (PC)
) 2.0 Hz, PCHCH3], 20.4 [d, J (PC) ) 7.0 Hz, PCHCH3], 19.8
[d, J (PC) ) 5.0 Hz, PCHCH3], 18.7 (s, PCHCH3), 18.2 (s, CH3
of mes). 31P NMR (C6D6, 162.0 MHz): δ 29.5 (s). Anal. Calcd
for C32H40ClO3OsP: C, 52.70; H, 5.53. Found: C, 52.17; H, 5.50
P r ep a r a tion of [(m es)Os{K2(P ,O)-iP r 2P C(CO2Me)dC-
(CHP h 2)O}{C2(CO2Me)2}]P F 6 (23). A solution of 22 (137 mg,
0.19 mmol) in 10 mL of CH2Cl2 was treated with C2(CO2Me)2
(57 mg, 0.40 mmol) and then dropwise with a solution of AgPF6
(48 mg, 0.19 mmol) in 15 mL of CH2Cl2. After the reaction
mixture was stirred for 15 min at room temperature, the
solution was filtered and the filtrate was brought to dryness
in vacuo. The oily residue was treated with 10 mL of ether,
and when the mixture was stirred for 12 h, a solid was
P r epar ation of [(m es)OsCl{K2(P ,O)-iP r 2P CH2C(OMe)O}]-
CF 3CO2 (19c). A solution of 18 (73 mg, 0.14 mmol) in 10 mL
of methanol was treated with CF3CO2H (23 mg, 0.20 mmol)
and stirred for 20 min at room temperature. The solvent was
removed, and the residue was washed three times with 5 mL
portions of ether and dried: pale yellow solid; yield 84 mg
(95%); mp 166 °C dec; Λ ) 79 cm2 Ω-1 mol-1. Anal. Calcd for
C
20H31ClF3O4OsP (649.1): C, 37.01; H, 4.81. Found: C, 36.87;
H, 4.78.
P r epar ation of [(m es)OsCl{κ2(P ,O)-iP r 2P CH2C(OMe)O}]-
CF 3SO3 (19d ). A solution of 18 (154 mg, 0.29 mmol) in 10 mL
of benzene was treated with CF3SO3H (100 µL, 0.88 mmol)
and stirred for 1 h at room temperature. After the solvent was
removed, a pale yellow oil was obtained, which was washed
twice with 5 mL portions of hexane and dried in vacuo: yield
177 mg (94%); Λ ) 72 cm2 Ω-1 mol-1. Anal. Calcd for C19H31
-
ClF3O5OsPS (685.2): C, 33.31; H, 4.56; S, 4.68. Found: C,
33.24; H, 4.70; S, 4.72.
P r ep a r a tion of [(m es)OsCl{K2(P ,O)-iP r 2P CHdC(OMe)-
O}] (20). A suspension of 16a (115 mg, 0.17 mmol) in 5 mL of
THF was treated with a suspension of KOtBu (19 mg, 0.17
mmol) in 5 mL of THF and stirred for 30 min at room
temperature. The solvent was removed, and the residue was
extracted with 30 mL of hexane/CH2Cl2 (2:1). After the extract
was brought to dryness in vacuo, a pale yellow microcrystalline

1194 Organometallics, Vol. 18, No. 7, 1999
Ta ble 5. Cr ysta llogr a p h ic Da ta for 9, 11, 22, a n d 23
Werner et al.
C18H34ClOOsP (9)
C19H36ClF6NOsP2 (11)
C32H40ClO3OsP (22)
C38H46F6O7OsP2 (23)
fw
523.07
680.08
729.26
980.89
cryst size, mm3
0.1 × 0.25 × 0.5
0.40 × 0.40 × 0.20
orthorhombic
Pbcn (No. 60)
8192 rflns, 2° < θ < 25°
16.144(2)
0.05 × 0.13 × 0.15
0.08 × 0.20 × 0.35
cryst syst
space group
cell dimens determn
a, Å
b, Å
c, Å
triclinic
monoclinic
monoclinic
P1h (No. 2)
23 rflns, 10° < θ < 14°
P21/n (No. 14)
23 rflns, 10° < θ < 14°
11.455(4)
12.731(4)
23.013(2)
P21/c (No. 14)
24 rflns, 5° < θ < 18°
10.550(3)
13.840(3)
28.130(3)
8.060(4)
8.481(4)
15.46(1)
79.67(4)
89.56(4)
78.05(4)
1017(1)
2
16.481(1)
18.289(3)
R, deg
â, deg
γ, deg
V, Å3
Z
92.04(2)
99.820(5)
4866(1)
8
1.857
3354(2)
4
1.444
4047(2)
4
1.610
d
calcd, g cm-3
1.709
temp, K
293(2)
6.494
ω/θ
48
193(2)
5.535
æ/ω
50.12
293(2)
3.964
ω/θ
48
293(2)
3.309
ω/θ
48
µ, mm-1
scan method
2θ(max), deg
tot. no. of rflns
3446
37 863
5535
5562
no. of unique rflns
no. of obsd rflns (I > 2σ(I))
no. of rflns used for
refinement
3186 (R(int) ) 0.0106)
42854 (R(int) ) 0.0452)
3800
4284
5240 (R(int) ) 0.0202)
4027
5239
5178 (R(int) ) 0.0213)
3846
5177
3085
3186
no. of params refined
final R indices (I > 2σ(I))
210
314
351
487
R1 ) 0.0219,
wR2 ) 0.0590a
R1 ) 0.0232,
wR2 ) 0.0599a
1.055/-0.889
R1 ) 0.0262,
wR2 ) 0.0633a
R1 ) 0.0320,
wR2 ) 0.0661
2.561/-0.760
R1 ) 0.0439,
wR2 ) 0.1294a
R1 ) 0.0753,
wR2 ) 0.1439a
2.556/-0.479
R1 ) 0.0331,
wR2 ) 0.0687a
R1 ) 0.0668,
wR2 ) 0.0812a
0.655/-0.430
R indices (all data)
resid electron density, e Å-3
a
2
2
2
w-1 ) [σ2Fo + (0.040P)2 + 1.2636P] (9), w-1 ) [σ2Fo + (0.03252 + 11.6154P] (11), w-1 ) [σ2Fo + (0.0346P)2 + 13.7168P] (22), and
w-1 ) [σ2Fo + (0.0271P)2 + 10.3744P] (23), where P ) (Fo + 2Fc2)/3.
2
2
1
obtained. The orange solid was separated from the mother
liquor, washed with small amounts of ether, and dried: yield
164 mg (89%); mp 142 °C dec; Λ ) 68 cm2 Ω-1 mol-1. IR
(KBr): ν(CtC) 1863, ν(CdO) 1725, 1715, 1700, ν(CdO +Cd
eV) m/z 521 (M+). IR (CH2Cl2): ν(CdO) 1644 cm-1. H NMR
(400 MHz, C6D6): δ 4.69 (s, 3H, C6H3Me3), 3.13 [dd, J (PH) )
10.2, J (HH) ) 16.0 Hz, 1H, one H of PCH2], 2.55 [dd, J (PH) )
9.1, J (HH) ) 16.0 Hz, 1H, one H of PCH2], 2.44 (m, 1H,
PCHCH3), 1.91 (s, 9H, C6H3Me3), 1.77 (m, 1H, PCHCH3), 0.95
[dd, J (PH) ) 15.7, J (HH) ) 7.4 Hz, 3H, PCHCH3], 0.87, 0.85
(both m, 6H, PCHCH3), 0.76 [dd, J (PH) ) 13.1, J (HH) ) 6.9
Hz, 3H, PCHCH3]. 13C NMR (100.6 MHz, CDCl3): δ 182.6 [d,
J (PC) ) 7.6 Hz, CO2], 95.7 [d, J (PC) ) 1.9 Hz, CMe of mes],
72.7 [d, J (PC) ) 3.8 Hz, CH of mes], 27.3 [d, J (PC) ) 33.4 Hz,
PCH2], 25.4 [d, J (PC) ) 29.5 Hz, PCHCH3], 24.0 [d, J (PC) )
30.5 Hz, PCHCH3], 19.2 (s, PCHCH3), 19.1 (s, CH3 of mes),
18.8 [d, J (PC) ) 1.6 Hz, PCHCH3], 17.5 [d, J (PC) ) 4.2 Hz,
PCHCH3]. 31P NMR (162.0 MHz, CDCl3): δ 13.4 [s, J (187Os31P)
) 257.7 Hz]. Anal. Calcd for C17H28ClO2OsP: C, 39.19; H, 5.42.
Found: C, 39.01; H, 5.69.
X-r a y Str u ctu r a l Deter m in a tion of Com p ou n d s 9, 11,
22, a n d 23. Single crystals of 9 were grown from hexane at 0
°C, those of 11 and 23 from hexane/CH2Cl2 (6:1) at 10 °C, and
those of 22 from hexane/toluene (5:1) at room temperature.
Crystal data collection parameters are summarized in Table
5. Intensity data were corrected by Lorentz and polarization
effects, and a semiempirical absorption correction was applied
in each case (minimum transmission 44.55% (9), 21.56% (11),
73.37% (22), and 59.72% (23); maximum transmission 40.40%
(11), near 100% (9, 22, and 23). The structures of 11, 22, and
23 were solved by direct methods (SHELXS-86 and SHELXS-
97),21 and that of 9 was solved by the Patterson method
(SHELXS-86). Atomic coordinates and the anisotropic thermal
parameters of non-hydrogen atoms were refined by full-matrix
least squares on F2 (SHELXL-93 and SHELXL-97).22 In 11
there are two PF6 anions in the asymmetric unit lying on 2-fold
axes. One of them is disordered and was refined with distance
restraints. Both anions were refined with restraints for the
anisotropic displacement parameters. For 11 an extinction
1
C), 1505 cm-1. H NMR (400 MHz, CDCl3): δ 7.31, 7.22, 7.13
(all m, 10H, C6H5), 6.40 (s, 3H, C6H3Me3), 3.92, 3.68 (both s,
6H, OCH3), 3.32 (m, 1H, PCHCH3), 3.14 (s, 3H, OMe), 2.50
(m, 1H, PCHCH3), 2.11 (s, 1H, CHPh2), 1.97 (s, 9H, C6H3Me3),
1.41 [dd, J (PH) ) 14.6, J (HH) ) 6.8 Hz, 3H, PCHCH3], 1.05
[dd, J (PH) ) 18.8, J (HH) ) 7.3 Hz, 3H, PCHCH3], 0.92 [dd,
J (PH) ) 16.4, J (HH) ) 7.2 Hz, 3H, PCHCH3], 0.85 [dd, J (PH)
) 17.8, J (HH) ) 6.8 Hz, 3H, PCHCH3]. 13C NMR (100.6 MHz,
CD3NO2): δ 201.0 [d, J (PC) ) 11.1 Hz, CO], 167.9 [d, J (PC) )
4.0 Hz, PCCO2], 160.6, 159.7 (both s, CCO2), 143.4, 141.3,
131.1, 131.0, 129.9, 128.4, 128.1 (all s, C6H5), 116.7 (s, CMe of
mes), 101.6 (s, CH of mes), 95.9, 95.4 (both s, CdC), 67.0 [d,
J (PC) ) 59.4 Hz, PCdC], 56.6 [d, J (PC) ) 6.1 Hz, CHPh2],
55.2, 54.0, 51.9 (all s, OCH3), 36.1 [d, J (PC) ) 33.2 Hz,
PCHCH3], 25.2 [d, J (PC) ) 34.2 Hz, PCHCH3], 19.8 (s,
PCHCH3), 19.0 [d, J (PC) ) 5.1 Hz, PCHCH3], 18.5 (s, CH3 of
mes), 18.3 [d, J (PC) ) 2.0 Hz, PCHCH3], 17.5 [d, J (PC) ) 3.1
Hz, PCHCH3]. 31P NMR (162.0 MHz, CDCl3): δ 55.7 (s, PiPr2),
-144.3 [sept, J (PF) ) 712.1 Hz, PF6-]. Anal. Calcd for
C
38H46F6O7OsP2 (980.9): C, 46.53; H, 4.73. Found: C, 46.27;
H, 4.62.
Rea ction of Com p ou n d 20 w ith HCl. A slow stream of
dry HCl was passed for 20 s through a solution of 20 (65 mg,
0.12 mmol) in 10 mL of benzene at room temperature. After
the reaction mixture was stirred for 10 min, the solvent was
removed and the orange residue dried in vacuo. It was
1
identified by comparison of the H and 31P NMR spectra with
those of an authentic sample as [(mes)OsCl2{κ1(P)-iPr2PCH2-
CO2Me}] (14).7 The yield was quantitative.
P r ep a r a tion of [(m es)OsCl{K2(P ,O)-iP r 2P CH2C(O)O}]
(24). A solution of 20 (135 mg, 0.25 mmol) in 5 mL of acetone
was treated with excess water (ca. 100 µL) and stirred for 10
min at room temperature. The solvent was removed, and the
yellow residue was washed three times with 5 mL portions of
ether and dried: yield 121 mg (92%); mp 196 °C dec; MS (70
(21) Sheldrick, G. M. Acta Crystallogr. Sect. A 1990, 46, 467-473.
(22) (a) Sheldrick, G. M. SHELXL-93; University of Go¨ttingen,
Go¨ttingen, Germany, 1993. (b) Sheldrick, G. M. SHELXL-97; Univer-
sity of Go¨ttingen, Go¨ttingen, Germany, 1997.

Os(II) Mesitylene Complexes with Phosphine Ligands
Organometallics, Vol. 18, No. 7, 1999 1195
correction with an coefficient of 0.000 49(5) was applied. The
positions of all hydrogen atoms were calculated according to
ideal geometry and were refined by using the riding method,
except for all hydrogen atoms of 9, which were found and
refined isotropically.
analysis), and Degussa AG (gifts of chemicals). G.H. is
particularly grateful to the Alexander von Humboldt
Foundation for supporting a 3 month visit to the
Australian National University.
Ack n ow led gm en t . We thank the Deutsche For-
schungsgemeinschaft (Grant No. SFB 347) and the
Fonds der Chemischen Industrie for financial support.
Moreover, we gratefully acknowledge support by R.
Schedl and C. P. Kneis (DTA and elemental analysis),
M.-L. Scha¨fer and Dr. W. Buchner (NMR spectra), Prof.
Dr. D. Stalke and B. Weberndo¨rfer (X-ray structure
Su p p or tin g In for m a tion Ava ila ble: Tables of data col-
lection parameters, bond lengths and angles, positional and
thermal parameters, and least-squares planes for 9, 11, 22,
and 23. This material is available free of charge via the
Internet at http://pubs.acs.org.
OM980909E