A series of mono- and dihydrido- as well as mono- and dimethylosmium(II) complexes containing [(mes)Os(CNR)] as a building block

Article abstract of DOI:10.1016/S0022-328X(99)00394-0

The dihydridoosmium(II) complexes [(mes)OsH₂(CNR)] (7-10) were prepared in excellent yield from the dichloroosmium(II) precursors [(mes)OsCl₂(CNR)] upon treatment with 10% magnesium amalgam in THF in the presence of ethanol. Under similar conditions, the methylisocyanide derivative [(mes)OsH₂(CNMe)] (6) as well as the monohydrido compounds [(mes)OsH(X)(CNMe)] (11, 13) were obtained. The same methodology using [(mes)OsCl(C₆H₅)(CNR)] as the starting material was applied for the preparation of the hydrido(phenyl)osmium(II) complexes [(mes)OsH(C₆H₅)(CNR)] (19-23) which were also isolated in almost quantitative yield. Treatment of these complexes with HCl in CH₂Cl₂ at -78°C led to the cleavage of the osmium-phenyl but not the osmium-hydride bond. Reactions of [(mes)OsCl₂(CNR)] with MeLi/LiCl gave exclusively the dimethylosmium(II) compounds [(mes)Os(CH₃)₂(CNR)] (29-32) while the corresponding reactions with MeLi/LiI afforded a mixture of 29-32 and the monomethyl derivatives [(mes)OsI(Me)(CNR)] (26, 33-35). A cyclic carbeneosmium(II) complex 37 was obtained from [(mes)OsCl₂(CNPh)] and MeLi/LiI followed by treatment with deactivated Al₂O₃. The etheneosmium(0) compound [(mes)Os(C₂H₄)(CNMe)] (38) was prepared from the dimethylosmium(II) precursor 29 and briefly investigated as starting material for photochemical C-H activation reactions.

Full text of DOI:10.1016/S0022-328X(99)00394-0

www.elsevier.nl/locate/jorganchem
Journal of Organometallic Chemistry 593–594 (2000) 192–201
A series of mono- and dihydrido- as well as mono- and
dimethylosmium(II) complexes containing [(mes)Os(CNR)] as a
building block
H. Werner *, U. Wecker
Institut fu¨r Anorganische Chemie der Uni6ersita¨t Wu¨rzburg, Am Hubland, D-97074 Wu¨rzburg, Germany
Received 4 June 1999; accepted 5 July 1999
Dedicated to Professor Fausto Calderazzo, a good friend and a creative scientist, on the occasion of his 70th birthday.
Abstract
The dihydridoosmium(II) complexes [(mes)OsH2(CNR)] (7–10) were prepared in excellent yield from the dichloroosmium(II)
precursors [(mes)OsCl2(CNR)] upon treatment with 10% magnesium amalgam in THF in the presence of ethanol. Under similar
conditions, the methylisocyanide derivative [(mes)OsH2(CNMe)] (6) as well as the monohydrido compounds
[(mes)OsH(X)(CNMe)] (11, 13) were obtained. The same methodology using [(mes)OsCl(C6H5)(CNR)] as the starting material was
applied for the preparation of the hydrido(phenyl)osmium(II) complexes [(mes)OsH(C6H5)(CNR)] (19–23) which were also
isolated in almost quantitative yield. Treatment of these complexes with HCl in CH2Cl2 at −78°C led to the cleavage of the
osmiumꢀphenyl but not the osmiumꢀhydride bond. Reactions of [(mes)OsCl2(CNR)] with MeLi/LiCl gave exclusively the
dimethylosmium(II) compounds [(mes)Os(CH3)2(CNR)] (29–32) while the corresponding reactions with MeLi/LiI afforded a
mixture of 29–32 and the monomethyl derivatives [(mes)OsI(Me)(CNR)] (26, 33–35). A cyclic carbeneosmium(II) complex 37 was
obtained from [(mes)OsCl2(CNPh)] and MeLi/LiI followed by treatment with deactivated Al2O3. The etheneosmium(0) compound
[(mes)Os(C2H4)(CNMe)] (38) was prepared from the dimethylosmium(II) precursor 29 and briefly investigated as starting material
for photochemical CꢀH activation reactions. © 2000 Elsevier Science S.A. All rights reserved.
Keywords: Osmium; Arene complexes; Isocyanide complexes; Hydrido complexes; Alkyl complexes; C–H activation
1. Introduction
Taking the similar s-donor/p-acceptor capabilities of
CO and CNR into consideration, we started a program
to prepare a series of halfsandwich-type mesityle-
neosmium(II) complexes in which apart from halide,
hydride, alkyl and aryl groups also various isocyanides
are coordinated to the metal center. In two recent
articles we described the preparation of the dichloro
compounds [(mes)OsCl2(CNR)] (R=Me, tBu, Ph, Cy,
Xyl) and their reactions with some organolithium and
Grignard reagents [6,7]. Moreover, we reported about
the synthesis and vibrational analysis of the dihydri-
doosmium(II) derivative [(mes)OsH2(CNMe)] which
was obtained from [(mes)OsCl2(CNMe)] and Mg/Hg in
THF in the presence of ethanol as a proton source [8].
The present paper is not only an extension of this
work but it also describes the preparation of a series
of monohydridoosmium(II) complexes [(mes)OsH-
(X)(CNR)] with X=Cl, Br, I and Ph as well as
of related mono- and dimethylosmium(II) counter-
Some years ago, we described a new family of
mesityleneosmiumcarbonyl complexes in which the
[(mes)Os(CO)] fragment (mes=mesitylene=1.3.5-
trimethylbenzene) was linked to two formally anionic
ligands such as H, Cl, Br, I, CH3, C6H5 and other
C-bonded units [1–3]. The aim of these studies was to
find out whether 18-electron compounds of the general
composition [(mes)OsX(X%)(CO)] are stable and usable
as precursors to generate 16-electron species
[(mes)Os(CO)] which, like the structurally related
[(C5R5)Ir(CO)] counterpart [4], could be a candidate for
activating CꢀH bonds. Based on a collaboration with
the Perutz group, an account of this work has already
appeared [5].
* Corresponding author.
0022-328X/00/$ - see front matter © 2000 Elsevier Science S.A. All rights reserved.
PII: S0022-328X(99)00394-0

H. Werner, U. Wecker / Journal of Organometallic Chemistry 593–594 (2000) 192–201
193
parts. Some preliminary results on intra- and inter-
molecular CꢀH activation reactions of the ethe-
neosmium(0) derivative [(mes)Os(C2H4)(CNMe)] will
also be discussed.
2. Results and discussion
The synthesis of the formerly unknown dihydridoos-
mium(II) complexes 7–10 followed the route which we
already described for the analogous compound 6.
Treatment of the dichloroosmium(II) precursors 2–5
(Scheme 1) with a slurry of magnesium amalgam (10%
of Mg) in THF and a small amount of ethanol gave
after workup and recrystallization from CH2Cl2–hex-
ane or sublimation in vacuo the OsH2 derivatives 7–10
in almost quantitative yield. The off-white solids, which
are soluble in all common organic solvents, were char-
acterized by elemental analysis, mass spectra and IR as
well as NMR spectroscopic techniques. The most typi-
cal feature of the NMR spectra is the high-field reso-
Scheme 2.
The hydrido(iodo)osmium(II) complex 13, which can
be considered as a counterpart of compound 11, was
obtained as a byproduct in the reaction of the diiodo
derivative 12 with Mg/Hg in THF/EtOH (Scheme 3).
The H-NMR spectrum of 13, which like 11 is a yellow
air-sensitive solid, displays the hydride resonance at l
−10.00 and thus in the same region as the related
dihydrido complex. In contrast, the H-NMR spectrum
of 11 exhibits the signal of the metal-bonded hydrogen
at l −8.27.
1
1
nance for the hydrido ligands in the H-NMR which
1
appears between l −10.00 and −10.25 as a singlet.
With regard to the reactivity of various hydridometal
compounds toward chloroform and other halocarbons
[9] we note that solutions of 6 in CHCl3 and CH2Cl2 are
stable for ca. 20 h without decomposition.
The bromo- and iodo(phenyl)osmium(II) compounds
14–18, which are readily accessible from the dichloro
derivatives 1–5 upon treatment with either PhMgBr or
PhMgI [6,7], also react with magnesium amalgam in
THF in the presence of ethanol to afford the hydri-
do(phenyl) complexes 19–23 in nearly quantitative
yield. While 19 and 23 are yellow, modestly air-sensitive
solids, the analogous compounds 20–22 are yellow oils
which like the analogous mono- and dihydrido deriva-
tives 6–11 and 13 are soluble in all common organic
solvents. The relevant spectroscopic data of 19–23 (i.e.
the CꢁN stretching vibration in the IR, the hydride
An alternative method for the preparation of the
dihydrido complex 6 with methylisocyanide as co-lig-
and consists in the reaction of 1 with an excess of zinc
dust in methanol in the presence of glacial acetic acid
(Scheme 2). After chromatographic separation of the
products, compound 6 was isolated in 63% yield. If the
starting material 1 was treated with Mg/Hg in THF in
the absence of ethanol, instead of the dihydrido com-
plex 6 the corresponding chloro(hydrido)osmium(II)
derivative 11 was formed in moderate yield. Although
we cannot exclude that traces of water were present in
the reaction system, we assume that for the generation
of 11 the solvent THF behaves as the proton source.
Earlier observations by S. Stahl are in agreement with
this hypothesis [10].
1
resonance in the H-NMR and the signal for the CNR
nuclei in the 13C-NMR spectra) are similar to those of
the other hydridoosmium(II) complexes prepared in
this work and thus deserve no further comments.
The reactivity of the new OsH(C6H5) derivatives
toward HCl was studied using 19, 20 and 22 as exam-
ples. The crucial question was whether the attack of the
electrophile would lead preferentially to a cleavage of
the OsꢀH or the OsꢀC6H5 bond. The answer is clear: if
a slow stream of dry HCl was passed through a solu-
tion of 19, 20 or 22 in CH2Cl2 at −78°C, a rapid
reaction occurred which gave the chloro(hy-
Scheme 1.
Scheme 3.

194
H. Werner, U. Wecker / Journal of Organometallic Chemistry 593–594 (2000) 192–201
Scheme 4.
drido)osmium(II) complexes 11, 24 and 25 in 90–95%
isolated yield (see Scheme 4). Under the chosen condi-
tions, neither the OsꢀH nor the OsꢀCNR bond are
attacked by the proton source. Therefore, the iso-
cyanide compounds 19, 20 and 22 behave similarly to
the carbonyl derivative [(mes)OsH(C6H5)CO] which re-
acts with HCl to form [(mes)OsHCl(CO)] and not
[(mes)OsCl(C6H5)(CO)] [11].
[(mes)OsCl(CH3)(CNR)] could not be detected. In con-
trast, if the methyllithium is generated from CH3I and,
therefore, the solution contains apart from MeLi also
LiI,
a mixture of both the dimethyl- and the
iodo(methyl)osmium(II) complexes is obtained. The
yield of the latter (26 and 33–35) is about 30–40%.
Similar
observations
had
been
made
with
[(mes)Os(CO)Cl2] as the starting material which upon
treatment with MeLi/LiI also gave a mixture of
[(mes)Os(CH3)2(CO)] and [(mes)OsI(CH3)(CO)], respec-
tively [1b].
The bromo(hydrido)osmium(II) complex 28 contain-
ing CNXyl as the isocyanide ligand was obtained on an
unexpected route. After we found that compound 1
reacted with both CH3MgI and C6H5MgI to give a
mixture of [(mes)OsI(R%)(CNMe)] (R%=Me, Ph) and
[(mes)OsI2(CNR)] [6], we studied also the reactivity of 1
and 5 toward other Grignard reagents. Treatment of 1
with C2H5MgI in ether gave, apart from 12 as the main
product, small amounts of the ethyl(iodo)osmium(II)
derivative 27 (Scheme 5), which was isolated as an
orange–yellow solid in 6% yield. Even with an excess of
C2H5MgI, the bis(ethyl) complex [(mes)Os(C2H5)2-
(CNMe)] could not be obtained. The reaction of the
xylylisocyanide complex 5 with C6H11MgBr led instead
of a mono- or bis(alkyl)osmium(II) compound to the
bromo(hydrido) complex 28 in 70% yield. Since we
observed the formation of cyclohexene as a byproduct,
it is conceivable that 28 is generated via a b-hydride
shift from the supposed bromo(cyclohexyl)osmium(II)
species [(mes)OsBr(C6H11)(CNXyl)] as an intermediate.
The 1H-NMR spectrum of 28 exhibits the hydride
signal at l −8.78, i.e. with a chemical shift between
that of 11 and 13.
The dimethylosmium(II) compounds 29–32 are yel-
low air-sensitive solids which are readily soluble in
organic solvents and can be sublimed in vacuo. In
solution (particularly in CHCl3 and CH2Cl2), even un-
1
der argon, slow decomposition occurs. The H-NMR
spectra of 29–32 display the signal for the OsCH3
protons at l 0.86–0.93 and thus significantly upfield
compared with the iodo(methyl) derivatives 26 [6] and
33–35 (l 1.62–1.74). In the 13C-NMR spectra of 29
and 32 the resonance of the methylcarbon nuclei ap-
pears also at relatively high field (l −21.7 and −20.5,
respectively). We note that although among the prod-
ucts of the reaction of 1, 2, 4 and 5 with MeLi/LiCl the
monomethyl complexes [(mes)OsCl(CH3)(CNR)] were
The results covering the reactivity of the dichloroos-
mium(II) complexes 1, 2, 4 and 5 toward methyllithium
are summarized in Scheme 6. The important point is
that the course of the reaction depends on the starting
material from which MeLi is generated. If CH3Cl is
used, the reagent consists of a mixture of MeLi and
LiCl and under these conditions the dimethylosmi-
um(II) compounds 29–32 are formed as the dominating
products in good to excellent yield. In this case, the
formation of the corresponding monomethyl derivatives
Scheme 5.

H. Werner, U. Wecker / Journal of Organometallic Chemistry 593–594 (2000) 192–201
195
Scheme 6.
not observed, the xylylisocyanide compound 32, which
was taken as an example, reacts with HCl in CH2Cl2 at
−78°C to give apart from [(mes)OsCl2(CNXyl)] (5)
also the chloro(methyl) derivative 36 as a minor
product.
this process a cationic intermediate [(mes)OsH(C2H4)-
(CNMe)]+ is generated together with some byproducts
possibly formed via attack of the electrophile at the
isocyanide ligand. The BF4 salt 39 (a yellow–brown,
extremely air-sensitive solid) of the supposed intermedi-
ate was obtained by protonation of 38 with HBF4 and
characterized by spectroscopic means.
The phenylisocyanide complex 3 behaves differently
toward methyllithium than the other compounds of the
general composition [(mes)OsCl2(CNR)] (see Scheme
7). If a suspension of 3 in benzene is treated with a
solution of MeLi/LiI in ether and the reaction mixture
worked up by chromatographic techniques, an orange–
red solid is isolated the analytical composition of which
corresponds to [(mes)OsI(CH3)(CNPh)]. The spectro-
scopic data reveal, however, that the compound is not
an isocyanideosmium(II) derivative but instead the
cyclic carbene complex 37 containing an ortho-meta-
lated phenyl ring. The most characteristic features in
Taking into consideration that the photochemistry of
halfsandwich-type
complexes
[(h5-C5R5)M(L)(L%)]
(M=Rh, Ir) [4,14,15] and [(h6-C6R6)M%(L)(L%)] (M%=
Ru, Os) [5,16], where the ligands L and L% were CO,
C2H4, PMe3, PiPr3, etc., provided an excellent opportu-
nity to develop routes for the inter- and intramolecular
activation of CꢀH bonds [17], the photochemical be-
havior of compound 38 was briefly investigated. Irradi-
ation of 38 in benzene at 5°C for 2 h results in the
elimination of ethene and the generation of the hydri-
do(phenyl)osmium(II) complex 19 which was first pre-
pared from 14 by iodide/hydride exchange (see Scheme
4). During the photolysis of 38 in benzene at 5°C, small
amounts of free mesitylene were equally formed. We
note that Jones and Feher reported that the bis(iso-
cyanide)rhodium(I) derivative [(h5-C5Me5)Rh(CNCH2-
CMe3)2] produces the imine PhCHꢂNCH2CMe3 upon
irradiation in benzene possibly via the hydri-
do(phenyl)rhodium(III) intermediate [(h5-C5Me5)RhH-
(C6H5)(CNCH2CMe3)] [18]. In our system, an ana-
logous CꢀC coupling reaction has not been observed.
In contrast to the photochemical reaction of 38 in
benzene at 5°C resulting in an intermolecular CꢀH
activation, irradiation of 38 in toluene-d8 at −85°C
1
the H-NMR spectrum of 37 are the NH resonance at
l 10.00 and the pattern for the C6H4 protons consisting
of three signals at l 7.73, 7.01 and 6.71 with the
intensity ratio 1:1:2. The 13C-NMR spectrum of 37
exhibits a low-field resonance at l 230.0, which is
typical for the carbene carbon atom of aminocarbene
complexes of this type [6,7]. In this context it should be
mentioned that compound 3 reacts with PhLi to give a
mixture of products among which is a relative of 37
containing two phenyl groups linked to the metal and
the carbene carbon atom. This complex was character-
ized by an X-ray crystal structure analysis [7].
The dimethylosmium(II) compound 29 can be em-
ployed as the starting material for the preparation of
the ethene(isocyanide)osmium(0) complex 38 (Scheme
8). Following earlier work from our laboratory about
the synthesis of ethenemetal derivatives [M(C2H4)Ln]
from dimethylmetal precursors [M(CH3)2Ln] [12,13], we
found that stepwise treatment of 29 with an equimolar
amount of [CPh3]PF6 in CH2Cl2 and subsequent reac-
tion with NaH in THF gave the osmium(0) compound
38 as a yellow air-sensitive solid in moderate yield.
There is spectroscopic evidence that in the initial step of
Scheme 7.

196
H. Werner, U. Wecker / Journal of Organometallic Chemistry 593–594 (2000) 192–201
Scheme 8.
leads to an isomerization of the starting material to give
40. The H-NMR spectrum of 40 displays the hydride
7: Yield 81 mg (93%), m.p. 102°C (dec.). Anal.
Found: C, 42.76; H, 6.10; N, 3.65. Calc. for
C14H23NOs: C, 42.51; H, 5.86; N, 3.54%. MS (70 eV):
m/z 397 (1, M+), 395 (2, M+−H2). IR (CH2Cl2):
1
resonance at l −9.71 while the signal pattern for the
vinyl protons appears at l 8.40, 6.85 and 5.83, respec-
tively. As expected from recent investigations of related
hydrido(vinyl) metal complexes [5,14–16,19], com-
pound 40 is stable in solution at room temperature (r.t.)
and does not isomerize back to 38 under ambient
conditions. Likewise to the behavior of 19, an insertion
of the isocyanide ligand into the vinylꢀosmium bond of
40 does not occur.
1
w(CN), w(OsH) 2101, 2056 cm−1. H-NMR (C6D6, 90
MHz): l 4.88 (s, 3H, C6H3 of mes), 2.32 (s, 9H, C6Me3
of mes), 1.07 (s, 9H, tBu), −10.24 (s, 2H, OsH2).
8: Yield 83 mg (91%), m.p. 100°C (dec.). Anal.
Found: C, 46.48; H, 4.58; N, 3.64. Calc. for
C16H19NOs: C, 46.25; H, 4.61; N, 3.37%. MS (70 eV):
m/z 415 (0.1, M+−H2). IR (CH2Cl2): w(CN), w(OsH)
1
2057, 2003 cm−1. H-NMR (C6D6, 90 MHz): l 6.98
(m, 5H, C6H5), 4.91 (s, 3H, C6H3 of mes), 2.25 (s, 9H,
C6Me3 of mes), −10.01 (s, 2H, OsH2).
3. Experimental
9: Yield 84 mg (90%), m.p. 74°C (dec.). Anal. Found:
C, 45.79; H, 6.28; N, 3.27. Calc. for C16H25NOs: C,
45.48; H, 5.98; N, 3.32%. MS (70 eV): m/z 423 (0.1,
M+), 421 (0.1, M+−H2). IR (CH2Cl2): w(CN), w(OsH)
All experiments were carried out under an atmo-
sphere of argon by using Schlenk techniques. The start-
ing materials 1–5, 12, and 14–18 were prepared
according to published methods [6,7]. IR: Perkin–
Elmer 1320. NMR: Jeol FX 90Q, Bruker AMX 400.
Mass spectra: Finnigan 90 MAT and 8200 MAT. Melt-
ing and decomposition points were determined by
DTA.
1
2084, 2062 cm−1. H MNR (C6D6, 90 MHz): l 4.90 (s,
3H, C6H3 of mes), 3.33 (m, 1H, CH of C6H11), 2.34 (s,
9H, C6Me3 of mes), 1.25 (m, 10H, CH2 of C6H11),
−10.25 (s, 2H, OsH2).
10: Yield 91 mg (93%), m.p. 119°C (dec.). Anal.
Found: C, 48.70; H, 5.27; N, 3.10. Calc. for
C18H23NOs: C, 48.74; H, 5.23; N, 3.16%. MS (70 eV):
m/z 445 (14, M+), 443 (17, M+−H2). IR (CH2Cl2):
3.1. Preparation of [(mes)OsH2(CNR)] (7–10)
1
w(CN), w(OsH) 2055, 1998 cm−1. H-NMR (C6D6, 400
A suspension of 0.22 mmol of the starting material
2–5 in 5 ml of THF was added dropwise to a slurry of
10% magnesium amalgam (formed from 25.0 mg of Mg
and 2.0 g of Hg) in 5 ml of THF and 0.1 ml of EtOH.
After the mixture was vigorously stirred for 1 h at r.t.,
the solution was decanted and the residue was washed
twice with 10 ml of THF. The combined solutions were
evaporated to dryness in vacuo, the remaining oily
residue was extracted three times with 10 ml of benzene
each, and the solvent was removed from the extracts.
An off-white solid was obtained, which was either
recrystallized from dichloromethane–hexane or sub-
limed in vacuo (60°C/5×10−5 mbar). On this route,
the methylisocyanide complex 6 had also been prepared
[6].
MHz): l 6.74 (s, 3H, C6H3 of Xyl), 4.92 (s, 3H, C6H3 of
mes), 2.32 (s, 6H, C6Me2 of Xyl), 2.29 (s, 9H, C6Me3 of
mes), −10.01 (s, 2H, OsH2). 13C-NMR (C6D6, 100.6
MHz): l 161.3 (s, CNXyl), 134.3 (s, CCH3 of Xyl),
132.1 (s, ipso-C of Xyl), 127.8, 125.0 (both s, CH of
Xyl), 99.1 (s, CCH3 of mes), 79.2 (s, CH of mes), 21.4
(s, CH3 of mes), 19.3 (s, CH3 of Ph and Xyl).
3.2. Alternati6e preparati6e procedure for
[(mes)OsH2(CNMe)] (6)
A suspension of 105 mg (0.25 mmol) of 1 in 15 ml of
methanol and 1.5 ml of acetic acid (99%) was treated
with excess of zinc dust (ca. 200 mg) and stirred for 4 h

H. Werner, U. Wecker / Journal of Organometallic Chemistry 593–594 (2000) 192–201
197
at r.t. The solvent was removed in vacuo, the residue
was extracted with 2 ml of benzene and the solution
was chromatographed on Al2O3 (basic, activity grade
III, height of column 5 cm). With benzene, a pale
yellow fraction was eluted which after it was brought to
dryness in vacuo gave an off-white solid. Yield 55 mg
(63%).
extracted twice with 10 ml of 1:1 hexane–benzene, and
the solvent was removed from the extracts. In the case
of 19 and 23 yellow microcrystalline solids, while in the
case of 20–22 yellow oils were obtained.
19: Yield 76 mg (88%), m.p. 83°C (dec.). Anal.
Found: C, 47.80; H, 4.98; N, 3.25. Calc. for
C17H21NOs: C, 47.53; H, 4.93; N, 3.26%. MS (70 eV):
m/z 431 (1, M+), 354 (1, M+−C6H5), 3.53 (1, M+−
C6H6). IR (CH2Cl2): w(CN), w(OsH) 2116 (br) cm−1
.
3.3. Preparation of [(mes)OsHCl(CNMe)] (11)
1H-NMR (C6D6, 90 MHz): l 7.98 (m, 2H, C6H5), 7.16
(m, 3H, C6H5), 4.66 (s, 3H, C6H3 of mes), 2.43 (s, 3H,
CNMe), 2.01 (s, 9H, C6Me3 of mes), −9.38 (s, 1H,
OsH).
This compound was prepared analogously as de-
scribed for 7–10 from 95 mg (0.22 mmol) of 1, but in
the absence of ethanol. After recrystallization from
dichloromethane–hexane a light yellow solid was ob-
tained. Yield 40 mg (47%), m.p. 155°C (dec.). Anal.
Found: C, 33.86; H, 4.07; N, 3.38. Calc. for
C11H16ClNOs: C, 34.06; H, 4.16; N, 3.61%. MS (70 eV):
m/z 389 (4, M+), 353 (7, M+−HCl). IR (CH2Cl2):
20: Yield 83 mg (88%), yellow oil. Anal. Found: C,
51.28; H, 5.81; N, 2.95. Calc. for C20H27NOs: C, 50.93;
H, 5.77; N, 2.97%. MS (70 eV): m/z 473 (5, M+), 395
(7, M+−C6H6), 312 (3, M+−C6H6−CNtBu). IR
1
(CH2Cl2): w(CN), w(OsH) 2101, 2064 cm−1. H-NMR
1
w(CN) 2158, w(OsH) 2039 cm−1. H-NMR (C6D6, 400
(C6D6, 90 MHz): l 7.95 (m, 2H, C6H5), 7.16 (m, 3H,
C6H5), 4.64 (s, 3H, C6H3 of mes), 2.01 (s, 9H, C6Me3 of
mes), 1.02 (s, 9H, tBu), −9.33 (s, 1H, OsH).
MHz): l 4.57 (s, 3H, C6H3 of mes), 2.42 (s, 3H,
CNMe), 2.08 (s, 9H, C6Me3 of mes), −8.27 (s, 1H,
OsH).
21: Yield 86 mg (88%), yellow oil. Anal. Found: C,
54.28; H, 4.81; N, 2.95. Calc. for C22H23NOs: C, 53.75;
H, 4.72; N, 2.85%. MS (70 eV): m/z 493 (4, M+), 415
(7, M+−C6H6). IR (CH2Cl2): w(CN), w(OsH) 2061,
3.4. Preparation of [(mes)OsHI(CNMe)] (13)
This compound was prepared analogously as de-
scribed for 7–10, using 133 mg (0.22 mmol) of 12 and
10% Mg/Hg in THF/EtOH as starting materials. After
the crude product was extracted from the reaction
mixture with benzene, the extract was concentrated to
ca. 2 ml in vacuo and the solution was then chro-
matographed on Al2O3 (basic, activity grade III, height
of column 5 cm). With hexane, a pale yellow fraction
was eluted which contained the dihydrido complex 6;
yield 51 mg (65%). Subsequently, with benzene a yellow
fraction was eluted from which after removal of the
solvent a yellow solid 13 was obtained; yield 27 mg
(26%), m.p. 124°C (dec.). Anal. Found: C, 27.86; H,
3.38; N, 2.70. Calc. for C11H16INOs: C, 27.56; H, 3.36;
N, 2.92%. MS (70 eV): m/z 481 (15, M+), 439 (8,
M+−H−CNMe), 354 (3, M+−I). IR (CH2Cl2):
1
2019 cm−1. H-NMR (C6D6, 90 MHz): l 8.00 (m, 4H,
C6H5), 6.83 (m, 6H, C6H5), 4.68 (s, 3H, C6H3 of mes),
1.97 (s, 9H, C6Me3 of mes), −9.19 (s, 1H, OsH).
22: Yield 87 mg (87%), yellow oil. Anal. Found: C,
53.53; H, 6.22; N, 2.74. Calc. for C22H29NOs: C, 53.09;
H, 5.87; N, 2.81%. MS (70 eV): m/z 499 (42, M+), 421
(55, M+−C6H6), 390 (100, M+−CNCy), 389 (83,
M+−H−CNCy), 312 (26, M+−C6H6−CNCy). IR
1
(CH2Cl2): w(CN), w(OsH) 2109, 2104 cm−1. H-NMR
(C6D6, 400 MHz): l 7.99 (m, 2H, C6H5), 7.13 (m, 3H,
C6H5), 4.67 (s, 3H, C6H3 of mes), 3.25 (m, 1H, C6H11),
2.04 (s, 9H, C6Me3 of mes), 1.38 (m, 6H, C6H11), 0.95
(m, 4H, C6H11), −9.30 (s, 1H, OsH). 13C-NMR (C6D6,
100.6 MHz): l 147.9 (s, CNCy), 146.4, 145.5, 126.6,
121.3 (all s, C6H5), 100.9 (s, CCH3 of mes), 78.2 (s, CH
of mes), 53.7 (s, CH of C6H11), 34.0, 25.4, 23.1, (all s,
CH2 of C6H11), 20.1 (s, CH3 of mes).
1
w(CN) 2151, w(OsH) 2043 cm−1. H-NMR (C6D6, 400
MHz): l 4.63 (s, 3H, C6H3 of mes), 2.54 (s, 3H,
CNMe), 2.08 (s, 9H, C6Me3 of mes), −8.27 (s, 1H,
OsH).
23: Yield 96 mg (92%), m.p. 95°C (dec.). Anal.
Found: C, 55.74; H, 5.29; N, 2.76. Calc. for
C24H27NOs: C, 55.47; H, 5.24; N, 2.70%. MS (70 eV):
m/z 521 (12, M+), 443 (5, M+−C6H6). IR (CH2Cl2):
3.5. Preparation of [(mes)OsH(C6H5)(CNR)] (19–23)
1
w(CN), w(OsH) 2059, 2024 cm−1. H-NMR (C6D6, 400
MHz): l 7.98 (m, 2H, C6H5), 7.11 (m, 3H, C6H5), 6.69
(s, 3H, C6H3 of Xyl), 4.70 (s, 3H, C6H3 of mes), 2.18 (s,
6H, C6Me2 of Xyl), 2.01 (s, 9H, C6Me3 of mes), −9.18
(s, 1H, OsH). 13C-NMR (C6D6, 100.6 MHz): l 159.6 (s,
CNXyl), 145.6, 143.9, 134.5, 131.4, 127.7, 126.9, 125.4,
121.6 (all s, ring-C of Xyl) 102.8 (s, CCH3 of mes), 80.1
(s, CH of mes), 20.2 (s, CH3 of mes), 19.0 (s, CH3 of
Xyl).
A solution of 0.20 mmol of the starting material
14–18 in 5 ml of THF was added dropwise to a slurry
of 10% magnesium amalgam (formed from 25.0 mg of
Mg and 2.0 g of Hg) in 5 ml of THF and 0.1 ml of
EtOH. After the mixture was stirred for 1.5 h, the
solution was decanted and the residue was washed
twice with 10 ml of THF. The combined solutions were
evaporated to dryness in vacuo, the oily residue was

198
H. Werner, U. Wecker / Journal of Organometallic Chemistry 593–594 (2000) 192–201
3.6. Preparation of [(mes)OsHCl(CNR)] (11, 24, 25)
from 19, 20, 22
for C13H20INOs: C, 30.77; H, 3.97; N, 2.76%. MS (70
eV): m/z 509 (1, M+), 480 (0.4, M+−C2H5), 439 (15,
M+−C2H5−CNMe). IR (CH2Cl2): w(CN) 2148
1
A slow stream of dry HCl was passed through a
solution of 0.20 mmol of 19, 20 or 22 in 5 ml of CH2Cl2
for 30 s at −78°C. The solvent was removed, the
residue was dissolved in 2 ml of benzene and the
solution was chromatographed on Al2O3 (basic, activity
grade III, height of column 5 cm). With 1:2 C6H6–
CH2Cl2 a yellow fraction was eluted which was evapo-
rated to dryness in vacuo. The remaining yellow solid
was washed twice with 1 ml of pentane (−30°C) and
dried. With 19 as the starting material, compound 11
was obtained; yield 73 mg (94%).
cm−1. H-NMR (C6D6, 90 MHz): l 4.46 (s, 3H, C6H3
of mes), 3.17, 2.18 (both m, 1H each, OsCH2), 2.65 (s,
3H, CNMe), 2.00 (s, 9H, C6Me3 of mes), 1.83 (dd,
J(HH)=7.6 Hz, 3H, CH2CH3).
3.8. Preparation of [(mes)OsHBr(CNXyl)] (28)
A suspension of 120 mg (0.23 mmol) of 5 in 8 ml of
benzene was treated at 5°C with 2.3 ml of a 0.25 M
solution (0.58 mmol) of C6H11MgBr in ether. After
warming to r.t., the reaction mixture was worked up
analogously as described for 26. With benzene, a yellow
fraction was eluted from which after removal of the
solvent a yellow solid was isolated; yield 84 mg (70%),
m.p. 146°C (dec.). Anal. Found: C, 41.09; H, 4.40; N,
2.60. Calc. for C18H22BrNOs: C, 41.38; H, 4.24; N,
2.68%. MS (70 eV): m/z 523 (1, M+), 522 (1, M+−H),
391 (2, M+−H−CNXyl). IR (CH2Cl2): w(CN),
24: Yield 78 mg (91%), m.p. 106°C (dec.). Anal.
Found: C, 39.54; H, 5.18; N, 3.15. Calc. for
C14H22ClNOs: C, 39.11; H, 5.16; N, 3.26%. MS (70 eV):
m/z 431 (25, M+), 347 (28, M+−H−CNtBu), 339
(100, (mes)OsHCN+), 312 (14, (mes)Os+). IR
(CH2Cl2): w(CN), w(OsH) 2125 (br) cm−1 1H-NMR
.
(C6D6, 400 MHz): l 4.59 (s, 3H, C6H3 of mes), 2.10 (s,
9H, C6Me3 of mes), 1.05 (s, 9H, tBu), −8.28 (s, 1H,
OsH). 13C-NMR (C6D6, 100.6 MHz): l 136.9 (s,
CNtBu), 99.2 (s, CCH3 of mes), 76.7 (s, CH of mes),
56.4 (s, CCH3 of tBu), 31.1 (s, CH3 of tBu), 19.9 (s,
CH3 of mes).
1
w(OsH) 2089, 2020 cm−1. H-NMR (C6D6, 400 MHz):
l 6.73 (s, 3H, C6H3 of Xyl), 4.63 (s, 3H, C6H3 of mes),
2.35 (s, 6H, C6Me2 of Xyl), 2.11 (s, 9H, C6Me3 of mes),
−8.78 (s, 1H, OsH).
25: Yield 85 mg (93%), m.p. 114°C (dec.). Anal.
Found: C, 41.82; H, 5.03; N, 3.03. Calc. for
C16H24ClNOs: C, 42.14; H, 5.30; N, 3.07%. MS (70 eV):
m/z 457 (5, M+), 422 (2, M+−HCl), 347 (5, M+−
H−CNCy), 312 (2, (mes)Os+). IR (CH2Cl2): w(CN),
w(OsH) 2130, 2048 cm−1.1H-NMR (C6D6, 400 MHz): l
4.60 (s, 3H, C6H3 of mes), 3.35 (m, 1H, CH of C6H11),
2.12 (s, 9H, C6Me3 of mes), 1.53 (m, 2H, C6H11), 1.37
(m, 4H, C6H11), 1.02, 0.93 (both m, 2H each, C6H11),
−8.21 (s, 1H, OsH).
3.9. Preparation of [(mes)Os(CH3)2(CNR)] (29–32)
A suspension of 0.25 mmol of 1, 2, 4 or 5 in 10 ml of
benzene was treated at 5°C with 0.55 ml of a 0.9 M
solution (0.50 mmol) of MeLi/LiCl in ether. After the
reaction mixture was warmed to r.t., it was stirred for
2.5 h and then ca. 100 mg of basic Al2O3 was added.
The solvent was removed in vacuo, the residue was
extracted with 2 ml of benzene and the extract was
chromatographed on Al2O3 (basic, activity grade III,
height of column 4 cm). With hexane, a yellow fraction
was eluted from which, after the solvent was evapo-
rated, a yellow solid was isolated.
3.7. Preparation of [(mes)OsI(C2H5)(CNMe)] (27)
This was carried out analogously as described for 26
[6]: a suspension of 150 mg (0.36 mmol) of 1 in 10 ml
of benzene was treated at 5°C with 2.2 ml of a 0.25 M
solution (0.55 mmol) of C2H5MgI in ether. After warm-
ing to r.t., the reaction mixture was stirred for 30 min,
and then ca. 100 mg of basic Al2O3 was added. The
solvent was removed in vacuo, the residue was ex-
tracted with 3 ml of 1:1 C6H6–CH2Cl2 and the extract
was chromatographed on Al2O3 (basic, activity grade
III, height of column 4 cm). With benzene an orange
fraction and with dichloromethane a red fraction were
eluted. From the latter, a red solid was isolated after
removal of the solvent and identified as 12 by compari-
son of the spectroscopic data with those of an authentic
sample [6]; yield 200 mg (92%). From the orange frac-
tion, an orange–yellow solid 27 was obtained; yield 10
mg (6%). Anal. Found: C, 31.09; H, 4.55; N, 2.35. Calc.
29: Yield 74 mg (79%). 13C-NMR (C6D6, 100.6
MHz): l 152.4 (s, CNMe), 99.0 (s, CH of mes), 77.8 (s,
CCH3 of mes), 28.5 (s, CH3 of CNMe), 18.5 (s, CH3 of
mes), −21.7 (s, OsCH3). Other spectroscopic and ana-
lytical data were already reported [6].
30: Yield 57 mg (54%), m.p. 46°C (dec.). Anal.
Found: C, 45.84; H, 6.65; N, 3.26. Calc. for
C16H27NOs: C, 45.37; H, 6.42; N, 3.31%. MS (70 eV):
m/z 425 (19, M+), 410 (10, M+−CH3), 327 (5, M+−
CH3−CNtBu), 312 (1, (mes)Os+). IR (CH2Cl2):
1
w(CN) 2100, 2045 cm−1. H-NMR (C6D6, 400 MHz): l
4.36 (s, 3H, C6H3 of mes), 1.97 (s, 9H, C6Me3 of mes),
1.17 (s, 9H, tBu), 0.86 (s, 6H, OsCH3).
31: Yield 84 mg (75%), m.p. 23°C (dec.). Anal.
Found: C, 47.99; H, 6.31; N, 3.20. Calc. for
C18H29NOs: C, 48.08; H, 6.50; N, 3.12%. MS (70 eV):
m/z 451 (42, M+), 436 (69, M+−CH3), 338 (100,

H. Werner, U. Wecker / Journal of Organometallic Chemistry 593–594 (2000) 192–201
199
(mes)OsCN+), 327 (7, M+−CH3−CNtBu), 312 (3,
OsCH3), 1.63 (m, 2H, C6H11), 1.46 (m, 4H, C6H11),
1.06, 0.96 (both m, 2H each, C6H11). 13C-NMR (C6D6,
100.6 MHz): l 136.8 (s, CNCy), 97.7 (s, CCH3 of mes),
78.0 (s, CH of mes), 54.0 (s, CH of C6H11), 34.1, 25.2,
23.0 (all s, CH2 of C6H11), 19.4 (s, CH3 of mes), −24.3
(s, OsCH3).
1
(mes)Os+). IR (CH2Cl2): w(CN) 2081, 2051 cm−1. H-
NMR (C6D6, 400 MHz): l 4.39 (s, 3H, C6H3 of mes),
3.38 (m, 1H, CH of C6H11), 2.00 (s, 9H, C6Me3 of mes),
1.56 (m, 4H, C6H11), 1.43, 1.08, 0.99 (all m, 2H each,
C6H11).
32: Yield 91 mg (77%), m.p. 122°C (dec.). Anal.
Found: C, 50.89; H, 5.89; N, 2.98. Calc. for
C20H27NOs: C, 50.93; H, 5.77; N, 2.97%. MS (70 eV):
m/z 473 (43, M+), 458 (54, M+−CH3), 327 (5, M+−
CH3−CNXyl), 312 (1, (mes)Os+). IR (CH2Cl2): w(CN)
35: Yield 47 mg (32%), m.p. 158°C (dec.). Anal.
Found: C, 39.56; H, 4.37; N, 2.43. Calc. for
C19H24INOs: C, 39.11; H, 4.15; N, 2.40%. MS (70 eV):
m/z 585 (37, M+), 570 (100, M+−CH3), 439 (81,
M+−CH3−CNXyl). IR (CH2Cl2): w(CN) 2082, 2017
1
2048, 2015 cm−1. H-NMR (C6D6, 400 MHz): l 6.80
cm−1 1H-NMR (C6D6, 400 MHz): l 6.75 (m, 3H,
.
(s, 3H, C6H3 of Xyl), 4.41 (s, 3H, C6H3 of mes), 2.33 (s,
6H, C6Me2 of Xyl), 1.95 (s, 9H, C6Me3 of mes), 0.93 (s,
6H, OsCH3). 13C-NMR (C6D6, 100.6 MHz): l 162.2 (s,
CNXyl), 133.7, 132.0, 127.8, 125.0 (all s, ring-C of
Xyl), 101.3 (s, CCH3 of mes), 80.0 (s, CH of mes), 19.4
(s, CH3 of Xyl), 18.6 (s, CH3 of mes), −20.5 (s,
OsCH3).
C6H3 of Xyl), 4.48 (s, 3H, C6H3 of mes), 2.37 (s, 6H,
C6Me2 of Xyl), 2.02 (s, 9H, C6Me3 of mes), 1.74 (s, 3H,
OsCH3). 13C-NMR (C6D6, 100.6 MHz): l 147.9 (s,
CNXyl), 135.1, 129.9, 127.9, 126.8 (all s, ring-C of
Xyl), 99.4 (s, CCH3 of mes), 80.1 (s, CH of mes), 19.6
(s, CH3 of Xyl), 19.5 (s, CH3 of mes), −24.0 (s,
OsCH3).
3.10. Reaction of compounds 1, 2, 4 and 5 with
MeLi/LiI
3.11. Preparation of [(mes)Os(CH3)Cl(CNXyl)] (36)
A slow stream of dry HCl was passed through a
solution of 71 mg (0.15 mmol) of 32 in 5 ml of CH2Cl2
for 30 s at −78°C. The solvent was removed, the
residue was dissolved in 2 ml of benzene and the
solution was chromatographed on Al2O3 (basic, activity
grade III, height of column 4 cm). With 1:3 C6H6–
CH2Cl2 a yellow fraction, and with CH2Cl2 an orange
fraction were eluted. From the latter, the dichloro
complex 5 (49 mg, 64%) was isolated. The yellow
fraction afforded after evaporation of the solvent com-
pound 36 as a yellow solid; yield 20 mg (27%), m.p.
146°C (dec.). Anal. Found: C, 46.66; H, 4.84; N, 2.86.
Calc. for C19H24ClNOs: C, 46.38; H, 4.92; N, 2.85%.
MS (70 eV): m/z 493 (10, M+), 478 (51, M+−CH3),
347 (49, M+−CH3−CNXyl). IR (CH2Cl2): w(CN)
2089 cm−1. 1H-NMR (C6D6, 400 MHz): l 6.74 (m, 3H,
C6H3 of Xyl), 4.45 (s, 3H, C6H3 of mes), 2.33 (s, 6H,
C6Me2 of Xyl), 1.94 (s, 9H, C6Me3 of mes), 1.60 (s, 3H,
OsCH3).
A suspension of 0.25 mmol of 1, 2, 4 or 5 in 10 ml of
benzene was treated at 5°C with 0.35 ml of a 1.5 M
solution (0.53 mmol) of MeLi/LiI in ether. After the
reaction mixture was warmed to r.t., it was worked up
analogously as described for 29–32. By chromatogra-
phy on Al2O3 two fractions were eluted: with 3:1 hex-
ane–benzene
a
yellow fraction and with 2:1
benzene–dichloromethane an orange fraction. From
the first, a yellow solid consisting of 29, 30, 31 or 32
was obtained; yield 40–55%. The orange fraction gave
after removal of the solvent an orange–yellow solid
consisting of 26, 33, 34 or 35. For 26, the yield was 37
mg (30%). For analytical and spectroscopic data of 26
see Ref. [6].
33: Yield 56 mg (42%), m.p. 111°C (dec.). Anal.
Found: C, 33.79; H, 4.63; N, 2.91. Calc. for
C15H24INOs: C, 33.65; H, 4.52; N, 2.62%. MS (70 eV):
m/z 537 (44, M+), 522 (28, M+−CH3), 466 (100,
M+−NtBu), 439 (93, (mes)OsI+). IR (CH2Cl2): w(CN)
1
2119, 2081 cm−1. H-NMR (C6D6, 90 MHz): l 4.44 (s,
3.12. Preparation of [(mes)Os{ꢂC(CH3)NHC6H4}I]
(37)
3H, C6H3 of mes), 2.03 (s, 9H, C6Me3 of mes), 1.62 (s,
3H, OsCH3), 1.15 (s, 9H, tBu). 13C-NMR (C6D6, 100.6
MHz): l 138.1 (s, CNtBu), 97.9 (s, CCH3 of mes), 78.0
(s, CH of mes), 56.5 (s, CCH3 of t-Bu), 31.6 (s, CH3 of
tBu), 19.4 (s, CH3 of mes), −24.3 (s, OsCH3).
A suspension of 130 mg (0.27 mmol) of 3 in 10 ml of
benzene was treated with 0.4 ml of a 1.5 M solution
(0.60 mmol) of MeLi/LiI in ether. After the reaction
mixture was warmed to r.t., it was worked up
analogously as described for 29–32. Column chro-
matography on Al2O3 (basic, activity grade III) with
benzene afforded a red fraction from which after re-
moval of the solvent an orange–red solid was obtained;
yield 66 mg (44%), m.p. 160°C (dec.). Anal. Found: C,
36.52; H, 3.50; N, 2.46. Calc. for C17H20INOs: C, 36.76;
H, 3.63; N, 2.52%. MS (70 eV): m/z 557 (85, M+), 439
34: Yield 47 mg (34%), m.p. 70°C. Anal. Found: C,
36.38; H, 4.60; N, 2.54. Calc. for C17H26INOs: C, 36.36;
H, 4.67; N, 2.49%. MS (70 eV): m/z 563 (42, M+), 548
(55, M+−CH3), 466 (100, M+−NCy), 439 (81, M+
−CH3−CNCy), 436 (44, M+−I), 312 (1, (mes)Os+).
1
IR (CH2Cl2): w(CN) 2125 cm−1. H-NMR (C6D6, 400
MHz): l 4.46 (s, 3H, C6H3 of mes), 3.47 (m, 1H, CH of
C6H11), 2.04 (s, 9H, C6Me3 of mes), 1.71 (s, 3H,

200
H. Werner, U. Wecker / Journal of Organometallic Chemistry 593–594 (2000) 192–201
(3, M+−CH3−CNPh), 430 (34, M+−I). IR
(CH2Cl2): w(NH) 3358 cm−1 1H-NMR (CDCl3, 400
solution displayed besides the signals of 38 (ca. 25%)
and free mesitylene (ca. 10%) those of the hydrido
complex 19; yield ca. 65%.
.
MHz): l 10.0 (br s, 1H, NH), 7.73, 7.01, 6.71 (all m,
4H, C6H4), 4.95 (s, 3H, C6H3 of mes), 3.09 (s, 3H,
ꢂCCH3), 2.20 (s, 9H, C6Me3 of mes). 13C-NMR
(CDCl3, 100.6 MHz): l 230.0 (s, OsꢂC), 152.0, 151.2,
140.4, 123.7, 121.5 (all s, ring-C of C6H4), 94.3 (s,
CCH3 of mes), 81.5 (s, CH of mes), 37.9 (s, ꢂCCH3),
19.8 (s, CH3 of mes).
3.16. Low-temperature photolysis of compound 38 in
toluene-d8
A solution of 15 mg (0.04 mmol) of 38 in 0.5 ml of
toluene-d8 was irradiated at −80°C in an NMR tube
with a 500 W UV lamp (Osram HBO) for 3 h. After the
1
3.13. Preparation of [(mes)Os(C2H4)(CNMe)] (38)
UV irradiation was stopped, the H-NMR spectrum of
the solution displayed besides the signals of free
1
A solution of 85 mg (0.22 mmol) of 29 in 4 ml of
ether was treated dropwise at −78°C with a solution of
82 mg (0.21 mmol) of [CPh3]PF6 in 3 ml of CH2Cl2.
After the reaction mixture was warmed to r.t., it was
stirred for 30 min and then concentrated to ca. 3 ml in
vacuo. Addition of 10 ml of ether led to the formation
of a brown oily precipitate, which was separated from
the mother liquor and washed three times with 5 ml of
ether. The oily residue was dissolved in 7 ml of THF
and under vigorous stirring the solution was treated
with an excess (ca. 150 mg) of NaH. After the reaction
mixture was stirred for 90 min, the solvent was re-
moved and the residue was extracted three times with
10 ml of benzene. The combined extracts were filtered,
the filtrate was evaporated in vacuo and the crude
product was recrystallized from hexane at −78°C. A
pale yellow solid was obtained; yield 27 mg (33%), m.p.
75°C (dec.). Anal. Found: C, 41.44; H, 5.08; N, 3.88.
Calc. for C13H19NOs: C, 41.14; H, 5.05; N, 3.69%. MS
(70 eV): m/z 381 (9, M+), 353 (15, M+−C2H4). IR
mesitylene those of compound 40; yield ca 35%. H-
NMR (toluene-d8, 90 MHz): l 8.40 (ddd, J(HH)=
18.0, 11.0, 1.5 Hz, 1H, OsCHꢂCH2), 6.85 (dd,
J(HH)=11.0, 4.8 Hz, 1H, one H of ꢂCH2 cis to
OsCH), 5.83 (dd, J(HH)=18.0, 4.8 Hz, 1H, one H of
ꢂCH2 trans to OsCH), 4.63 (s, 3H, C6H3 of mes), 2.70
(s, 3H, CNMe), 2.14 (s, 9H, C6Me3 of mes), −9.71 (br
s, 1H, OsH).
Acknowledgements
We gratefully acknowledge financial support from
the Deutsche Forschungsgemeinschaft (SFB 347), the
Fonds der Chemischen Industrie (Doktoranden-
stipendium for U.W.) and Degussa AG. Moreover, we
thank Dr. G. Lange and F. Dadrich (mass spectra),
M.-L. Scha¨fer and Dr. W. Buchner (NMR spectra), R.
Schedl (DTA measurements) and C.P. Kneis (elemental
analysis).
.
(hexane): w(CN) 1920 cm−1 1H-NMR (C6D6, 90
MHz): l 4.68 (s, 3H, C6H3 of mes), 2.71 (s, 3H,
CNMe), 2.19 (m, 2H, C2H4), 2.10 (s, 9H, C6Me3 of
mes), 1.72 (m, 2H, C2H4).
References
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Werner, S. Stahl, M. Schulz, Chem. Ber. 124 (1991) 707. (c) S.
Stahl, H. Werner, J. Am. Chem. Soc. 113 (1991) 2944.
[2] U. Wecker, H. Werner, J. Organomet. Chem. 424 (1992) 199.
[3] U. Wecker, H. Werner, K. Peters, H.-G. von Schnering, Chem.
Ber. 127 (1994) 1021.
[4] (a) J.K. Hoyano, W.A.G. Graham, J. Am. Chem. Soc. 104
(1982) 3723. (b) J.K. Hoyano, A.D. McMaster, W.A.G. Gra-
ham, J. Am. Chem. Soc. 105 (1983) 7190. (c) A.J. Rest, I.
Whitwell, W.A.G. Graham, J.K. Hoyano, A.D. McMaster, J.
Chem. Soc. Chem. Commun. (1984) 624. (d) W.A.G. Graham, J.
Organomet. Chem. 300 (1986) 81.
3.14. Preparation of [(mes)OsH(C2H4)(CNMe)]BF4 (39)
A solution of 30 mg (0.08 mmol) of 38 in 5 ml of
ether was treated at −78°C with a solution of HBF4 in
ether until the yellow color disappeared. A yellow–
brown solid precipitated which was separated from the
mother liquor, washed 5 times with 5 ml of ether and
dried; yield 32 mg (86%). IR (CH2Cl2): w(CN), w(OsH)
2200 cm−1. 1H-NMR (CD2Cl2, 90 MHz): l 5.99 (s, 3H,
C6H3 of mes), 3.54 (s, 3H, CNMe), 2.61 (m, 2H, C2H4),
2.44 (s, 9H, C6Me3 of mes), 2.23 (m, 2H, C2H4),
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1
irradiation was stopped, the H-NMR spectrum of the
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