Ruthenium complexes containing bis(diarylamido)/thioether ligands: Synthesis and their catalysis for the hydrogenation of benzonitrile

Article abstract of DOI:10.1021/om020340o

Treatment of the thioethers (RNH-o-C₆H₄)₂S (H₂[R₂NSN]; R = Xy, Xyf; Xy = 3,5-Me₂C₆H₃, Xyf = 3,5-(CF₃)₂C₆H₃) with 2 equiv of n-BuLi followed by addition of 0.5 equiv of [(η⁶-C₆H₆)RuCl₂]₂ in THF gave the bis(diarylamido)/thioether complexes [(η⁶-C₆H₆)Ru[R₂NSN]] (R = Xy (1a), R = Xyf (1b)) in moderate yields. In the presence of 1a (1 mol %) and PCy₃ (2 mol %; Cy = cyclohexyl), benzonitrile was catalytically hydrogenated to give benzylamine (72%) and benzylidenebenzylamine (27%) at 80 °C and 30 atm, while the hydrogenation with 1b as a catalyst precursor resulted in the formation of benzylamine (37%) and benzylidenebenzylamine (51%) under the same reaction conditions. The yield of benzylamine was improved up to 92% by using a catalyst mixture of 1a (1 mol %)/PCy₃ (2 mol %)/t-BuONa (10 mol %). On the other hand, the reaction of la with excess PMe₃ afforded the tris(trimethylphosphine) derivative [(PMe₃)₃Ru[Xy₂NSN]] (2). Treatment of 2 with excess PhCN, MeCN, or N₂H₄·H₂O resulted in the replacement of a PMe₃ ligand by these substrates to give [(PMe₃)₂LRu[Xy₂NSN]] (3, L = PhCN; 4, L = MeCN; 5, L = N₂H₄), while the reaction of 2 with benzoylhydrazine gave the κ²-benzoylhydrazido complex [(PMe₃)₂Ru(κ₂-(O,N)-PhC(O)= NNH₂)(H[Xy₂NSN])] (6). Structures of 1a, 1b, 2, 5, and 6 have been determined by X-ray crystallography.

Full text of DOI:10.1021/om020340o

Organometallics 2002, 21, 3897-3904
3897
Ru th en iu m Com p lexes Con ta in in g Bis(d ia r yla m id o)/
Th ioeth er Liga n d s: Syn th esis a n d Th eir Ca ta lysis for
th e Hyd r ogen a tion of Ben zon itr ile
Shin Takemoto,§ Harumi Kawamura,† Yoshiaki Yamada,† Takayoshi Okada,†
Atsushi Ono,† Eri Yoshikawa,† Yasushi Mizobe,‡ and Masanobu Hidai*,†
Department of Materials Science and Technology, Faculty of Industrial Science and
Technology, Science University of Tokyo, Noda, Chiba 278-8510, J apan, and Institute of
Industrial Science, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8505, J apan
Received April 29, 2002
Treatment of the thioethers (RNH-o-C6H4)2S (H2[R2NSN]; R ) Xy, Xyf; Xy ) 3,5-Me2C6H3,
Xyf ) 3,5-(CF3)2C6H3) with 2 equiv of n-BuLi followed by addition of 0.5 equiv of [(η6-C6H6)-
RuCl2]2 in THF gave the bis(diarylamido)/thioether complexes [(η6-C6H6)Ru[R2NSN]] (R )
Xy (1a ), R ) Xyf (1b)) in moderate yields. In the presence of 1a (1 mol %) and PCy3 (2 mol
%; Cy ) cyclohexyl), benzonitrile was catalytically hydrogenated to give benzylamine (72%)
and benzylidenebenzylamine (27%) at 80 °C and 30 atm, while the hydrogenation with 1b
as a catalyst precursor resulted in the formation of benzylamine (37%) and benzylideneben-
zylamine (51%) under the same reaction conditions. The yield of benzylamine was improved
up to 92% by using a catalyst mixture of 1a (1 mol %)/PCy3 (2 mol %)/t-BuONa (10 mol %).
On the other hand, the reaction of 1a with excess PMe3 afforded the tris(trimethylphosphine)
derivative [(PMe3)3Ru[Xy2NSN]] (2). Treatment of 2 with excess PhCN, MeCN, or N2H4‚
H2O resulted in the replacement of a PMe3 ligand by these substrates to give [(PMe3)2LRu-
[Xy2NSN]] (3, L ) PhCN; 4, L ) MeCN; 5, L ) N2H4), while the reaction of 2 with
benzoylhydrazine gave the κ2-benzoylhydrazido complex [(PMe3)2Ru(κ2-(O,N)-PhC(O)d
NNH2)(H[Xy2NSN])] (6). Structures of 1a , 1b, 2, 5, and 6 have been determined by X-ray
crystallography.
In tr od u ction
by the ruthenium(II) complex/diamine/KOH mixture
recently developed by Noyori et al.4 These findings show
the importance of heterolytic H2 activation for the
hydrogenation of CdO and CdN polar bonds. Thus, we
presume that late transition metal amido complexes
serve as catalysts for hydrogenation of a variety of polar
unsaturated substrates other than ketones and imines.
We have long been interested in hydrogenation of the
ΝtΝ triple bond of dinitrogen, which is polarized when
coordinated to a metal center in an end-on fashion.5
Previously, we have reported the reaction of the tung-
sten dinitrogen complex cis-[W(N2)2(PMe2Ph)4] with
acidic ruthenium η2-dihydrogen complexes, which leads
to the protonation of the coordinated dinitrogen on
tungsten by the heterolytic cleavage of the coordinated
dihydrogen on ruthenium.6,7 The reaction results in the
formation of ammonia from N2 and H2; however, elec-
trons for the reduction of N2 are supplied from tungsten
and the reaction is thus stoichiometric. We have now
turned our attention to amido complexes of late transi-
tion metals aiming at development of metal complexes
that effectively coordinate and activate both N2 and H2
molecules. In this paper, we report the synthesis of
Amido-metal bonds in late transition metal amido
complexes are known to react with dihydrogen to form
amine-hydride species.1 This process corresponds to the
heterolytic cleavage of dihydrogen by the aid of an
amido-metal bond to create a protonic N-H hydrogen
and a hydride on the metal. For instance, Fryzuk and
co-workers demonstrated that the ruthenium(II) com-
plex [RuCl(PPh3){(Ph2PCH2SiMe2)2N}] containing a tri-
dentate amido/bis(phosphine) ligand produces an amine-
hydride complex [RuHCl(PPh3){(Ph2PCH2SiMe2)2NH}]
upon treatment with dihydrogen.2 More recently, Morris
et al. have characterized the ruthenium(II) amido-
hydrido complex [RuH(NHCMe2CMe2NH2)(R-binap)]
(binap ) 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl),
which gives the diamine-dihydrido complex [RuH2(NH2-
CMe2CMe2NH2)(R-binap)] under H2.3 The latter reac-
tion provides evidence for involvement of the heterolytic
cleavage of dihydrogen on a Ru-N bond in the hydro-
genation of ketones, aldehydes, and imines catalyzed
† Science University of Tokyo.
‡ The University of Tokyo.
§ Present address: Department of Materials Science, Faculty of
Integrated Arts and Sciences, Osaka Prefecture University, Sakai,
Osaka 599-8531, J apan.
(4) Noyori, R.; Ohkuma, T. Angew. Chem., Int. Ed. 2001, 40, 40-
73.
(1) Fryzuk, M. D.; Montgomery, C. G. Coord. Chem. Rev. 1989, 95,
1-40.
(5) (a) Hidai, M.; Mizobe, Y. Chem. Rev. 1995, 95, 1115-1133. (b)
Hidai, M. Coord. Chem. Rev. 1999, 186, 99-108.
(6) (a) Nishibayashi, Y.; Iwai, S.; Hidai, M. Science 1997, 297, 540-
542. (b) Nishibayashi, Y.; Takemoto, S.; Iwai, S.; Hidai, M. Inorg. Chem.
2000, 39, 5946-5957.
(2) Fryzuk, M. D.; Montgomery, C. G.; Rettig, S. J . Organometallics
1991, 10, 467-473.
(3) Abdur-Rashid, K.; Faatz, M.; Lough, A. J .; Morris, R. H. J . Am.
Chem. Soc. 2001, 123, 7473-7474.
(7) Hidai, M.; Mizobe, Y. Pure Appl. Chem. 2001, 73, 261-263.
10.1021/om020340o CCC: $22.00 © 2002 American Chemical Society
Publication on Web 08/20/2002

3898 Organometallics, Vol. 21, No. 19, 2002
Takemoto et al.
ruthenium complexes containing tridentate bis(diaryl-
amido)/thioether ligands [(RN-o-C6H4)2S]2- ([R2NSN]2-
;
R ) Xy, Xyf; Xy ) 3,5-Me2C6H3, Xyf ) 3,5-(CF3)2C6H3)
and their catalysis for hydrogenation of the CtN triple
bond of benzonitrile, whose structure has some rele-
vance to that of the metal-bound dinitrogen molecule.
Resu lts a n d Discu ssion
Syn th esis of H2[R2NSN] a n d [(η6-C6H6)Ru [R2-
NSN]] (R ) Xy, Xyf). The ligand precursor (XyNH-o-
C6H4)2S (H2[Xy2NSN]) was prepared by the palladium-
catalyzed coupling reaction8 between the diamine (H2N-
o-C6H4)2S and 2 equiv of 5-bromo-m-xylene (eq 1). The
F igu r e 1. ORTEP diagram of 1a drawn at the 50%
probability level. Hydrogen atoms are omitted for clarity.
Ta ble 1. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for 1a a n d 1b
product was isolated as a yellow oil in ∼75% yield after
purification by flash chromatography on silica gel.
An analogous thioether H2[Xyf2NSN] containing 3,5-
(CF3)2C6H3 groups (Xyf) was also synthesized in a
similar manner. The ligands of this type were originally
developed by Schrock et al., who recently reported the
synthesis of a series of group 4 metal complexes
containing [(RN-o-C6H4)2S]2- (R ) i-Pr, t-Bu-d6)9 ligands
as well as the ether analogues [(RN-o-C6H4)2O]2- (R )
i-Pr, Cy, t-Bu-d6, 2,4,6-Me3C6H2)10,11 and demonstrated
that the zirconium complex [((t-Bu-d6-N-o-C6H4)2O)-
ZrMe(PhNMe2)][B(C6F5)4] initiates the living polymer-
ization of 1-hexene.12 We have chosen the bis(diaryl-
amido)/thioether ligand system for an entry into amido-
ruthenium chemistry because the diarylamide ligands
do not suffer from decomposition via the â-H-elimination
to imine-hydrides. Actually, we could not obtain any
amidoruthenium complex from the reaction of [(η6-
C6H6)RuCl2]2 with 2 equiv of the in situ generated
dilithium salt Li2[i-Pr2NSN] in THF. However, when
Li2[Xy2NSN] was employed, the reaction proceeded
smoothly to give the red crystalline bis(diarylamido)/
thioether complex [(η6-C6H6)Ru[Xy2NSN]] (1a ) in ∼60%
yield after recrystallization from dichloromethane-
1a
1b
Ru-N(1)
2.116(3)
2.070(3)
2.3277(11)
1.357(4)
1.420(4)
1.360(4)
1.429(4)
1.777(4)
1.786(4)
85.84(12)
119.2(2)
121.2(2)
117.4(3)
119.9(2)
117.6(2)
119.6(3)
103.72(16)
2.123(3)
2.091(3)
2.3310(7)
1.379(4)
1.409(4)
1.371(4)
1.408(4)
1.777(3)
1.783(3)
86.05(10)
118.69(19)
120.54(19)
117.1(2)
118.76(19)
118.6(2)
118.8(3)
102.17(14)
Ru-N(2)
Ru-S(1)
N(1)-C(1)
N(1)-C(13)
N(2)-C(7)
N(2)-C(19)
S(1)-C(6)
S(1)-C(12)
N(1)-Ru-N(2)
C(1)-N(1)-Ru
C(13)-N(1)-Ru
C(1)-N(1)-C(13)
C(7)-N(2)-Ru
C(19)-N(2)-Ru
C(7)-N(2)-C(19)
C(6)-S(1)-C(12)
1
methanol (eq 2). The H NMR spectrum of 1a exhibits
a resonance for the C6H6 moiety at 4.41 ppm, which is
characteristic of the η6-coordinated benzene ligand. The
simple spectral pattern of the XyNC6H4 moieties includ-
ing a singlet resonance for the methyl protons at 2.23
ppm indicates the presence of a plane of symmetry in
the molecule. The tridentate coordination of the [Xy2-
NSN]2- ligand in 1a was unequivocally confirmed by
an X-ray analysis; the molecular structure of 1a is
shown in Figure 1, and the selected bond lengths and
angles are listed in Table 1. The Ru-N distances of
2.070(3) and 2.116(3) Å are comparable to that of the
Ru-sulfonamido bond observed for the 18-electron
complex [(p-cymene)RuX(TsNCHPhCHPhNH2)] (X ) H,
Cl),13 but longer than that of the Ru-alkylamido bond
(1.897(6) Å) in the 16-electron complex [(p-cymene)Ru-
(TsNCHPhCHPhNH)], in which a significant double-
bond character of the Ru-N bond is implied.13 The sum
(8) (a) Wolfe, J . P.; Wagaw, S.; Buchwald, S. L. J . Am. Chem. Soc.
1996, 118, 7215-7216. (b) Louie, J .; Driver, M. S.; Hamann, B. C.;
Hartwig, J . F. J . Org. Chem. 1997, 62, 1268-1273.
(9) Graf. D. D.; Schrock, R. R.; Davis, W. M.; Stumpf, R. Organo-
metallics 1999, 18, 843-852.
(10) Baumann, R.; Stumpf, R.; Davis, W. M.; Liang, L.-C.; Schrock,
R. R. J . Am. Chem. Soc. 1999, 121, 7822-7836.
(11) Liang, L.-C.; Schrock, R. R.; Davis, W. M. Organometallics 2000,
19, 2526-2531.
(12) Baumann, R.; Davis, W. M.; Schrock, R. R. J . Am. Chem. Soc.
1997, 119, 3830-3831.
(13) Haack, K.-J .; Hashiguchi, S.; Fujii, A.; Ikariya, T.; Noyori, R.
Angew. Chem., Int. Ed. Engl. 1997, 36, 285-288.

Ru Complexes with Bis(diarylamido)/ Thioether
Organometallics, Vol. 21, No. 19, 2002 3899
Ta ble 2. Hyd r ogen a tion of Ben zon itr ilea
yield (%)b,c
entry
catalyst
1a /2PCy3
1a /2PMe3
1a
H2 (atm)
conv (%)
PhCH2NH2
(PhCH2)2NH
PhCHdNCH2Ph
1
2
3
4
5
6
7
8
30
30
30
60
30
30
30
30
60
30
30
30
100
100
7
100
98
98
<1
90
72
61
0
67
92
88
0
37
67
85
80
49
<1
16
<1
<1
4
<1
<1
1
27
23
6
33
2
10
<1
51
26
13
3
1a /2PCy3
1a /2PCy3/10t-BuONa
1a /2PCy3/10EtONa
1b
1b/2PCy3
1b/2PCy3
1b/2PCy3/10t-BuONa
[RuH2(H2)2(PCy3)2]
3
9
100
98
95
7
<1
6
10
11
12
100
16
34
a
Conditions: complexes 1a , 1b, [RuH2(H2)2(PCy3)2], or 3 (0.050 mmol), THF (5 mL), benzonitrile (5.00 mmol), temperature 80 °C, time
18 h. Determined by GLC. c Based on benzonitrile.
b
other ligands, as established for many other arene-
ruthenium(II) complexes.14 Thus, a solution of 1a in
THF was heated at 80 °C for 48 h in the presence of 2
equiv of PCy3 (Cy ) cyclohexyl) in an attempt to trap
the nascent Ru[Xy2NSN] species by PCy3. After recrys-
tallization from THF-hexanes a dark violet crystalline
solid was obtained, which showed resonances ascribed
to the PCy3 and [Xy2NSN]2- ligands in 1:1 intensity
1
ratio in its H NMR spectrum and a singlet resonance
at 62.0 ppm in the 31P{1H} NMR spectrum. No signal
1
assignable to the η6-C6H6 ligand was found in the H
NMR spectrum. These spectroscopic features suggest
that the η6-C6H6 ligand in 1a is displaced by 1 equiv of
PCy3 ligand during the reaction. However, the complex-
ity in the 1H NMR spectrum and failure to obtain
suitable crystals for an X-ray analysis precluded further
characterization of the product. Nevertheless, thermal
displacement of the η6-C6H6 ligand with PCy3 opens up
potentially vacant coordination sites on ruthenium,
which may be used for activation of dihydrogen and
substrates. To test the potential of the Ru[Xy2NSN]
species as a hydrogenation catalyst, benzonitrile was
hydrogenated by using 1a as a catalyst precursor. The
results are summarized in Table 2. In the presence of 1
mol % of 1a and 2 mol % of PCy3, benzonitrile was
smoothly hydrogenated at 80 °C in THF under 30 atm
of H2 with 100% conversion within 18 h to give benzyl-
amine in 72% yield together with benzylidenebenzyl-
amine (27%) and a trace amount of dibenzylamine
(entry 1). These minor products are considered to arise
from the nucleophilic addition of benzylamine to the
coordinated benzonitrile or benzaldehyde imine and
subsequent ammonia elimination/hydrogenation pro-
cesses.15 In place of PCy3, trimethylphosphine can be
used as a coligand. The catalyst 1a /2PMe3 exhibited
almost the same activity as 1a /2PCy3, but caused
formation of an increased amount of dibenzylamine
(entry 2). In the absence of the phosphine ligand,
complex 1a showed a very low catalytic activity (entry
3). For the hydrogenation with the 1a /2PCy3 catalyst
system, increase of the initial H2 pressure from 30 to
60 atm did not largely affect the product selectivity
(entry 4). However, the selectivity toward benzylamine
was remarkably improved when t-BuONa or EtONa (10
F igu r e 2. ORTEP diagram of 1b drawn at the 50%
probability level. Hydrogen atoms are omitted for clarity.
of bond angles around the N(1) and N(2) atoms are
357.8° and 357.1°, respectively, and these nitrogen
atoms adopt almost planar geometry. The C-N bond
lengths in the XyN moieties (1.420(4) and 1.429(4) Å)
are longer than those in the NC6H4 units (1.357(4) and
1.360(4) Å). This indicates a larger degree of delocal-
ization of the lone pair electrons on the amide nitrogen
toward the phenylene ring than to the Xy ring.
A similar reaction between Li2[Xyf2NSN] and [(η6-
C6H6)RuCl2]2 afforded an analogous complex [(η6-
C6H6)Ru[Xyf2NSN]] (1b) (eq 2) in ∼40% yield. The
structure of 1b was also determined by an X-ray
analysis (Figure 2 and Table 1). The bond lengths and
angles around the ruthenium atom are almost the same
as those observed for 1a , and the geometries around the
amide nitrogen atoms are also trigonal planar. The
difference between the two C-N bond lengths in com-
plex 1b (∼0.03 Å) is smaller than that of complex 1a
(∼0.065 Å) (vide supra), probably due to the more
electron-withdrawing nature of the Xyf ring than the
Xy ring.
Hyd r ogen a tion of Ben zon itr ile Ca ta lyzed by 1a
or 1b. Although ruthenium complexes 1a and 1b adopt
coordinatively saturated 18-electron configurations, the
η6-C6H6 ligand is expected to be readily replaced by
(14) Doucet, H.; Ohkuma, T.; Murata, K.; Yokozawa, T.; Kozawa,
M.; Katayama, E.; Englang, A. H.; Ikariya, T.; Noyori, R. Angew.
Chem., Int. Ed. 1998, 37, 1703-1707.
(15) Bianchini, C.; Santo, V. D.; Meli, A.; Oberhauser, W.; Psaro,
R.; Vizza, F. Organometallics 2000, 19, 2433-2444.

3900 Organometallics, Vol. 21, No. 19, 2002
Takemoto et al.
Sch em e 1
mol %) was added as a catalyst component (entries 5
and 6). We presume that the alkoxide base abstracts
the NH proton from the ruthenium amine-hydride
species derived from the heterolytic cleavage of dihy-
drogen by the amidoruthenium complex to generate the
anionic hydridoruthenate species, which may promote
the hydride transfer to the cyano carbon of benzonitrile
much faster than the nucleophilic attack of benzyl-
amine.
To explore the effect of the substituent of amide
ligands on the catalytic performance, we employed 1b
as a catalyst precursor. Although complex 1b itself was
a very poor precatalyst (entry 7), the catalytic activity
of 1b/2PCy3 was as high as that of 1a /2PCy3 (entry 8).
In contrast to the 1a /2PCy3 catalyst system, the catalyst
1b/2PCy3 produced benzylidenebenzylamine as a major
product. When the hydrogenation was conducted with
the initial H2 pressure of 60 atm, the product selectivity
was shifted to benzylamine (entry 9). Therefore, we
presume that the electronic nature of the substituents
on the amide nitrogen affects both the reactivity of the
amidoruthenium species toward dihydrogen and the
relative rate of the hydride transfer and the nucleophilic
attack of benzylamine to the coordinated benzonitrile.
Similarly to the 1a /2PCy3/10t-BuONa catalyst system,
the catalyst 1b/2PCy3/10t-BuONa also produced ben-
zylamine in high selectivity (entry 10).
There are several reports on the homogeneous hydro-
genation of benzonitrile catalyzed by ruthenium com-
plexes. The complex [(triphos)Ru(NCMe)3](CF3SO3)2
(triphos ) (Ph2PCH2)3CMe) has been reported to yield
benzylidenebenzylamine in high selectivity,15 while the
anionic hydridoruthenate complex K[(Ph3P)2(Ph2PC6H4)-
RuH2] has been known to produce benzylamine as a sole
product.16 To reveal the role of the amide-ruthenium
bond in the hydrogenation of benzonitrile presented
here, we employed [RuH2(η2-H2)2(PCy3)2]17 as a refer-
ence catalyst, which showed a catalytic activity compa-
rable to that of 1a /2PCy3, but the product distribution
was different (entry 10). We conclude that the active
catalyst species derived from 1a /2PCy3 is not the same
as that formed from [RuH2(η2-H2)2(PCy3)2], but probably
contains amide-ruthenium bond(s) because the 1H
NMR spectrum of the reaction mixture of the hydroge-
nation of benzonitrile with 1a /2PCy3 did not exhibit
resonances ascribed to the free thioether ligand H2[Xy2-
NSN]. The finding that the product distribution is
significantly affected by the kind of substituent on the
amide ligands also supports the catalysis by an ami-
doruthenium species. A plausible reaction mechanism
for the hydrogenation of benzonitrile with the 1a /2PCy3
catalyst system is depicted in Scheme 1, which includes
the heterolytic activation of dihydrogen on the Ru-N
bond and the subsequent transfer of H+ and H- to the
coordinated nitrile.
[(PMe3)3Ru[Xy2NSN]] (2), which was isolated as yellow
crystals in ∼70% yield (eq 3). The 31P{1H} NMR
spectrum of 2 revealed two phosphorus resonances at
2.2 and -12.9 ppm as a doublet and a triplet, respec-
tively, indicating the presence of three phosphorus
1
nuclei, of which two are chemically equivalent. The H
NMR spectrum of 2 showed a methyl resonance for the
unique PMe3 ligand at 0.53 ppm as a doublet, and that
for the remaining two PMe3 ligands was found at 1.11
ppm as a weakly coupled virtual triplet. An X-ray
diffraction study shows that the structure of 2 is
distorted octahedral and the [Xy2NSN]2- ligand adopts
fac geometry (Figure 3, Table 3). The Ru-N bond
lengths are ∼0.1 Å as long as those in 1a .
When complex 2 was treated with benzonitrile, the
PMe3 ligand located at the position trans to the sulfur
atom was selectively substituted to give the benzonitrile
complex [(PMe3)2(PhCN)Ru[Xy2NSN]] (3) in 49% yield
(eq 4). The 31P{1H} NMR spectra of 3 displayed a singlet
Syn th esis a n d Rea ctivities of [(P Me3)3Ru [Xy2-
NSN]]. Although we could not characterize the product
formed from the reaction between 1a and PCy3 (vide
infra), treatment of 1a with an excess amount of
trimethylphosphine (10 equiv) in DMF at 80 °C for 2
days afforded the tris(trimethylphosphine) derivative
(16) Grey, R. A.; Pez, G. P.; Wallo, A. J . Am. Chem. Soc. 1981, 103,
7536-7542.
(17) Chaudret, B.; Poilblanc, P. Organometallics 1985, 4, 1722-
1726.

Ru Complexes with Bis(diarylamido)/ Thioether
Organometallics, Vol. 21, No. 19, 2002 3901
F igu r e 3. ORTEP diagram of 2 drawn at the 50%
F igu r e 4. ORTEP diagram of 5 drawn at the 50%
probability level. Hydrogen atoms are omitted for clarity.
probability level. Hydrogen atoms are omitted for clarity.
Ta ble 3. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for [(P Me3)2LRu [Xy2NSN]] (L ) P Me3 (2),
L ) N2H4 (5))
We have also investigated the reaction of 2 with
hydrazines. Similarly to the reaction of 2 with organo-
nitriles, the reaction of 2 with hydrazine hydrate
produced the bis(trimethylphosphine)-hydrazine com-
plex [(PMe3)2(N2H4)Ru[Xy2NSN]] (5) in 63% yield (eq
2
5
Ru-N(1)
2.211(3)
2.204(3)
2.3262(9)
2.2997(10)
2.3450(10)
2.3901(10)
2.158(3)
2.194(3)
2.2748(10)
2.2874(11)
2.3145(11)
2.165(3)
1.479(5)
96.88(4)
90.86(8)
95.80(9)
86.43(11)
118.5(2)
1
Ru-N(2)
4). In the H NMR spectrum of 5, the NH protons gave
Ru-S(1)
rise to a multiplet at 3.94 ppm attributed to the Ru-
bound NH2 group and a broad triplet at 2.91 ppm
(3J HH ) 4.4 Hz) assigned to the terminal NH2 group.
These features are consistent with the terminal end-on
coordination of the hydrazine ligand. The structure of
5 was further confirmed by an X-ray analysis (Figure
4), and the selected structural parameters are listed in
Table 3. When complex 2 was treated with benzoylhy-
drazine, the product was not a simple adduct but the
κ2-benzoylhydrazido complex [(PMe3)2Ru(κ2-(O,N)-PhC-
(O)dNNH2)(H[Xy2NSN])] (6), which was isolated in 88%
Ru-P(1)
Ru-P(2)
Ru-L
N(3)-N(4)
P(1)-Ru-P(2)
P(1)-Ru-L
P(2)-Ru-L
N(1)-Ru-N(2)
Ru-N(3)-N(4)
93.13(4)
91.00(3)
100.82(3)
89.01(10)
1
resonance due to the PMe3 ligands, and the H NMR
spectra exhibited a single PMe resonance as a weakly
coupled virtual triplet. The infrared spectra of 3 showed
an absorption band at 2257.2 cm-1, which is character-
istic of the end-on coordinated nitrile ligand. These
features are consistent with substitution of the unique
PMe3 ligand in 2 by the nitrile ligand. Complex 3 may
be an intermediate in the hydrogenation of benzonitrile
with the 1a /2PMe3 catalyst system. Actually, the cata-
lytic activity of 3 is almost comparable to that of 1a /
2PMe3 (Table 2; entries 2 and 12).
1
yield (eq 5). The H NMR spectrum of 6 is consistent
Complex 2 also reacts with acetonitrile, a more
weakly coordinating ligand than benzonitrile, to give an
analogous nitrile complex [(PMe3)2(MeCN)Ru[Xy2NSN]]
(4) in good yield (eq 4). This has prompted us to examine
the reaction of 2 with dinitrogen. When a solution of 2
in THF was treated with 30 atm of N2 at room temper-
ature for 48 h, a new absorption band was observed at
2164.9 cm-1 with a weak intensity in the infrared
spectrum of the solution just after the pressure of N2
was decreased to 1 atm. This may indicate the formation
of [(PMe3)2(N2)Ru[Xy2NSN]]. The band disappeared
when the solution was bubbled with argon or kept for
several hours under ambient N2 pressure. The low
conversion of 2 and the instability of the product
prevented further characterization of the product.
with a formula that has no symmetry about ruthenium,
and the 31P{1H} NMR spectrum of 6 showed two doublet
resonances at 17.7 and 12.4 ppm attributable to the two
inequivalent PMe3 ligands. The structure of 6 was
determined by an X-ray analysis (Figure 5 and Table
4), which revealed the presence of a bidentate mono-
amido/thioether H[Xy2NSN]- ligand with a dangling
XyNHC6H4 arm. The η2-benzoylhydrazido ligand is
bound to ruthenium with the oxygen and terminal
nitrogen atoms forming a five-membered chelate ring.
The N(3)-N(4) and C(35)-O(1) bonds are recognized as
single bonds with bond lengths of 1.475(5) and 1.297(5)

3902 Organometallics, Vol. 21, No. 19, 2002
Takemoto et al.
performed under an inert atmosphere of nitrogen using
standard Schlenk techniques. Toluene, hexanes, diethyl ether
(Et2O), and THF were dried over sodium benzophenone ketyl
and distilled before use. Acetonitrile and dichloromethane were
dried over P2O5 and distilled before use. Methanol was dried
over magnesium methoxide and distilled before use. (H2N-o-
C6H4)2S,9 [Pd(dba)2] (dba ) dibenzylideneacetone),18 [(η6-C6H6)-
RuCl2]2,19 and [RuH2(η2-H2)2(PCy3)2]17 were prepared according
to the literature, while other chemicals were commercially
purchased and used as received. NMR spectra were recorded
on
a J EOL J NM-EX-400 spectrometer. IR spectra were
recorded on a Shimadzu FTIR-8300 spectrometer. Elemental
analyses were performed on a Perkin-Elmer 2400 series II
CHN analyzer. High-resolution FABMS analyses were per-
formed on a J EOL J MS600 instrument. Quantitative GLC
analyses of organic compounds were performed on a Shimadzu
GC-14B instrument equipped with a flame ionization detector
using a 25 m × 0.25 mm CBP1 fused silica capillary column.
GC-MS analyses were carried out on a Shimadzu GC-MS QP-
5050 spectrometer.
P r ep a r a tion of H2[Xy2NSN]. A 200 mL round-bottomed
flask equipped with a magnetic stir bar and a nitrogen inlet
was charged with (H2N-o-C6H4)2S (3.00 g, 13.9 mmol), [Pd-
(dba)2] (400 mg, 0.696 mmol), S-BINAP (433 mg, 0.693 mmol),
t-BuONa (2.94 g, 30.6 mmol), toluene (80 mL), and XyBr (5.14
g, 27.8 mmol). The reaction mixture was magnetically stirred
at 80 °C for 18 h under a nitrogen atmosphere. After cooling
to room temperature, the mixture was filtered and concen-
trated to a small volume on a rotary evaporator. The crude
product was purified by silica gel column chromatography
(hexanes-ethyl acetate). Evaporation of the band eluted with
5% ethyl acetate-hexanes gave H2[Xy2NSN] as a pale yellow
oil. Yield: 4.50 g, 76%. HRFABMS calcd for C28H28N2S: m/e,
424.19733; found 424.19693. 1H NMR (400 MHz, CDCl3): δ
7.31-7.28 (m, 4H, C6H4), 7.17, 6.82 (m, 2H each, C6H4), 6.68
(s, 4H, Me2C6H3), 6.63 (s, 2H, Me2C6H3), 6.30 (br s, 2H, NH),
2.25 (s, 12H, Me2C6H3).
F igu r e 5. ORTEP diagram of 6 drawn at the 50%
probability level. Hydrogen atoms except for the N-H
hydrogen atoms are omitted for clarity.
Ta ble 4. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for 6·(C6H14)0.5·(C6H12)
0.5
Ru-N(1)
Ru-S(1)
Ru-P(1)
Ru-P(2)
Ru-N(3)
2.141(3)
Ru-O(1)
2.115(3)
1.475(5)
1.302(5)
1.297(5)
2.121
2.3137(11)
2.2629(12)
2.2848(12)
2.108(3)
N(3)-N(4)
N(4)-C(35)
C(35)-O(1)
O(1)‚‚‚H(1)
N(1)-Ru-S(1)
P(1)-Ru-P(2)
N(3)-Ru-O(1)
Ru-N(3)-N(4)
82.51(9)
96.21(5)
76.70(12)
113.6(2)
N(3)-N(4)-C(35)
Ru-O(1)-C(35)
O(1)-C(35)-N(4)
N(2)-H(1)‚‚‚O(1)
110.5(3)
112.2(2)
126.9(4)
144.4
P r ep a r a tion of H2[Xyf2NSN]. A 200 mL round-bottomed
flask equipped with a magnetic stir bar and a nitrogen inlet
was charged with (H2N-o-C6H4)2S (2.16 g, 9.99 mmol), [Pd-
(dba)2] (288 mg, 0.50 mmol), S-BINAP (467 mg, 0.75 mmol),
t-BuONa (2.10 g, 21.9 mmol), toluene (50 mL), and 3,5-bis-
(trifluoromethyl)bromobenzene (5.86 g, 20.0 mmol). The reac-
tion mixture was magnetically stirred at 80 °C for 3 days under
a nitrogen atmosphere. After cooling to room temperature, the
mixture was filtered and concentrated to a small volume on a
rotary evaporator. The crude product was purified by column
chromatography on alumina with diethyl ether as eluent to
give H2[Xyf2NSN] as a dark red oil. Yield: 3.5 g, 55%.
HRFABMS calcd for C28H16F12N2S: m/e, 640.08423; found
640.08421. 1H NMR (CDCl3): δ 7.27 (s, 2H, C6H3(CF3)2), 7.19-
7.14 (m, 10H), 6.90 (dt, 2H, C6H4), 6.34 (s, 2H, NH). 13C{1H}
NMR (CDCl3): δ 144.42, 140.84, 133.35, 129.59, 124.57,
124.35, 119.67, 116.50, 114.16, 132.83 (q, 2J CF ) 35 Hz, CF3C),
Å, respectively, while the C(35)-N(4) bond length of
1.302(5) Å falls in the range of double-bond distances.
The N-H hydrogen atom of the XyNHC6H4 moiety was
found at the position close to the O(1) atom with an
O(1)‚‚‚H(1) distance of 2.121 Å and an N(2)-H(1)‚‚‚O(1)
angle of 144.4°, indicating the presence of an N-H‚‚‚O
hydrogen bond between these atoms.
Con clu sion
We have synthesized new amidoruthenium complexes
1a and 1b by employing tridentate bis(diarylamido)/
thioether ligands. Complexes 1a and 1b catalyze the
hydrogenation of benzonitrile when combined with
PCy3. Although the catalytic activity of 1a /2PCy3 is
comparable to that of the hydrido complex [RuH2(η2-
H2)2(PCy3)2], the finding that the product distribution
is significantly affected by the kind of substituent on
the amide ligands supports the catalysis of the ami-
doruthenium complex where the Ru-N bond is retained
during the reaction. Complex 1a reacts with excess
trimethylphosphine to form [(PMe3)3Ru[Xy2NSN]] (2).
The PMe3 ligand trans to the sulfur ligand is readily
substituted by organonitriles and hydrazines. Our stud-
ies are in progress to elucidate the detailed mechanism
of the hydrogenation of benzonitrile catalyzed by the
amidoruthenium complexes.
1
123.83 (q, J CF ) 273 Hz, CF3).
P r ep a r a tion of [(η6-C6H6)Ru [Xy2NSN]] (1a ). To a solu-
tion of H2[Xy2NSN] (2.72 g, 6.41 mmol) in THF (75 mL) was
added a solution of n-BuLi (8.5 mL, 13.5 mmol; 1.59 M in
n-hexane) at -78 °C, and the pale yellow solution was stirred
at -78 °C for 30 min. Then, [(η6-C6H6)RuCl2]2 (1.61 g, 3.22
mmol) was added to the solution, and the mixture was slowly
warmed to room temperature with stirring over 12 h and
stirred at room temperature for 2 days to form a dark red
solution. Solvents were evaporated, and the residue was
extracted with dichloromethane (60 mL). Slow diffusion of
MeOH to the concentrated extract afforded 1a as dark red
(18) Ukai, T.; Kawazura, H.; Ishii, Y.; Bonnet, J . J .; Ibers, J . A. J .
Organomet. Chem. 1974, 65, 253-266.
(19) Bennet, M. A.; Smith, A. K. J . Chem. Soc., Dalton Trans. 1974,
233-241.
Exp er im en ta l Section
Gen er a l P r oced u r es. All manipulations except for the
purification of the thioethers H2[R2NSN] (R ) Xy, Xyf) were

Ru Complexes with Bis(diarylamido)/ Thioether
Organometallics, Vol. 21, No. 19, 2002 3903
0.5·(C6H12
Ta ble 5. Cr ysta llogr a p h ic Deta ils for 1a , 1b·(CH2Cl2)0.5, 2, 5, a n d 6·(C6H14
)
)
0.5
1a
1b‚(CH2Cl2)0.5
2
5
6‚(C6H14)0.5‚(C6H12)
0.5
empirical formula
fw
C34H32N2SRu
601.75
C34.5H21F12ClSRu
860.11
C37H53N2P3SRu
751.85
C34H48N4P2SRu
707.83
C47H65N4OP2SRu
897.10
cryst size (mm)
cryst syst
a (Å)
b (Å)
c (Å)
0.55 × 0.15 × 0.03
monoclinic
17.355(7)
8.359(3)
20.938(8)
110.701(4)
2841.2(19)
P21/n
0.50 × 0.30 × 0.10
monoclinic
34.251(2)
8.7147(4)
22.8057(15)
100.658(3)
6689.8(7)
C2/c
0.55 × 0.15 × 0.03
monoclinic
12.440(3)
16.292(4)
19.821(5)
112.051(3)
3723.3(15)
P21/c
0.40 × 0.10 × 0.10
monoclinic
17.236(6)
11.625(4)
18.245(6)
108.639(4)
3464(2)
P21/a
0.80 × 0.25 × 0.20
monoclinic
14.466(4)
21.312(6)
16.090(5)
103.387(4)
4826(3)
P21/n
â (deg)
V (Å3)
space group
Z
4
8
4
4
4
D
calc (g/cm3)
1.407
0.651
1.708
0.708
1.341
0.634
1.357
0.634
1.235
0.471
abs coeff (mm-1
)
F000
1240
3416
1576
1480
1892
no. of reflns collected
no. of ind reflns
20 436
6481
1.171
0.0615
23 909
7248
1.105
0.0473
27 233
8392
1.047
0.0464
25 280
7861
1.062
0.0502
35 542
11 018
1.049
0.0621
goodness of fit on F2
R1 [I > 2σ(I)]
wR2 (all data)
0.1078
0.1118
0.1141
0.1152
0.1606
largest diff peak and
0.36 and -0.28
0.87 and -0.52
0.99 and -0.41
0.60 and -0.37
1.04 and -0.36
hole (e Å-3
)
crystals. Yield: 2.40 g, 62%. Anal. Calcd for C34H32N2SRu: C,
67.86; H, 5.36; N, 4.66. Found: C, 67.57; H, 5.35; N, 4.63. H
NMR (400 MHz, C6D6): δ 7.65 (d, 2H, C6H4), 6.79-6.70 (m,
4H, C6H4), 6.34 (t, 2H, C6H4), 6.78 (s, 4H, Me2C6H3), 6.72 (s,
2H, Me2C6H3), 4.41 (s, 6H, C6H6), 2.23 (s, 12H, Me2C6H3).
(m, 2H, Ph), 6.64 (m, 2H, C6H4), 6.49 (d, 2H, C6H4), 6.38 (br s,
4H, Me2C6H3), 6.35 (s, 2H, Me2C6H3), 6.00 (t, 2H, C6H4), 1.91
(s, 12H, Me2C6H3), 1.28 (vt, 18H, PMe3). 31P{1H} NMR (CD2-
1
Cl2): δ 9.2 (s). IR (KBr): 2257.2 (ν(CtN)) cm-1
.
P r ep a r a tion of [(P Me3)2(MeCN)Ru [Xy2NSN]] (4). A
suspension of 2‚(THF)2 (448 mg, 0.50 mmol) in MeCN (35 mL)
was stirred at 60 °C for 14 h to form a yellow suspension. The
mixture was heated at reflux to give a yellow solution, from
which yellow crystals of 4 were obtained on cooling to -30 °C.
Yield: 259 mg, 72%. Anal. Calcd for C36H47N3P2SRu: C, 60.32;
P r ep a r a tion of [(η6-C6H6)Ru [Xyf2NSN]]‚0.5CH2Cl2 (1b‚
(CH2Cl2)0.5). To a solution of H2[Xyf2NSN] (0.108 g, 0.169
mmol) in THF (8 mL) was added a solution of n-BuLi (234 µL,
0.374 mmol; 1.6 M in n-hexane) at -78 °C, and the orange
solution was stirred at -78 °C for 30 min. To this was added
[(η6-C6H6)RuCl2]2 (42 mg, 0.0840 mmol), and the mixture was
slowly warmed to room temperature with stirring over 12 h
to form a dark red solution. Solvents were evaporated, and
the residue was extracted with dichloromethane (ca. 10 mL).
The dichloromethane extract was loaded on a column of
alumina and then eluted with diethyl ether to give a red band,
which was collected and evaporated to dryness. Recrystalli-
zation of the red solid from dichloromethane-hexanes afforded
1b‚(CH2Cl2)0.5 as dark red crystals. Yield: 55 mg, 38%. Anal.
Calcd for C34H20N2F12SRu‚0.5CH2Cl2: C, 48.18; H, 2.46; N,
1
H, 6.61; N, 5.86. Found: C, 60.21; H, 6.69; N, 6.11. H NMR
(C6D6): δ 7.75 (dd, 2H, C6H4), 7.13 (dd, 2H, C6H4), 6.93 (dt,
2H, C6H4), 6.61 (br s, 4H, Me2C6H3), 6.56 (s, 2H, Me2C6H3),
6.39 (dt, 2H, C6H4), 2.14 (s, 12H, Me2C6H3), 1.06 (vt, 18H,
PMe3), 0.96 (s, 3H, MeCN). 31P{1H} NMR (C6D6): δ 9.4 (s). IR
(KBr): 2266.2 (ν(CtN)) cm-1
.
P r ep a r a tion of [(P Me3)2(N2H4)Ru [Xy2NSN]] (5). To a
solution of 2‚(THF)2 (100 mg, 0.11 mmol) in THF (5 mL) was
added N2H4‚H2O (56 mg, 1.1 mmol), and the mixture was
stirred at 60 °C for 18 h. Volatiles were removed in vacuo,
and the residue was recrystallized from dichloromethane-
hexanes to give 5 as a yellow crystalline solid. Yield: 49 mg,
63%. Anal. Calcd for C34H48N4P2SRu: C, 57.69; H, 6.83; N,
1
3.26. Found: C, 48.01; H, 2.38; N, 3.17. H NMR (400 MHz,
C6D6): δ 7.57 (s, 2H, C6H3(CF3)2), 7.46 (d, 2H, C6H4), 7.20 (br
s, 4H, C6H3(CF3)2), 6.63 (t, 2H, C6H4), 6.45 (d, 2H, C6H4), 6.34
(t, 2H, C6H4), 4.11 (s, 6H, C6H6).
1
7.92. Found: C, 57.74; H, 6.76; N, 7.80. H NMR (CD2Cl2): δ
7.37 (dd, 2H, C6H4), 6.65 (dt, 2H, C6H4), 6.51 (s, 2H, Me2C6H3),
P r epar ation of [(P Me3)3Ru [Xy2NSN]]‚(THF)2 (2‚(THF)2).
To a solution of 1a (600 mg, 1.0 mmol) in DMF (23 mL) was
added a solution of PMe3 in toluene (1.0 M, 10 mL), and the
mixture was heated at 80 °C for 2 days to form a yellow
solution. Volatiles were removed in vacuo, and the residual
solid was recrystallized from hot THF (10 mL) to give 2‚(THF)2
as yellow crystals. Yield: 650 mg, 73%. Single crystals of 2
suitable for X-ray diffraction study were obtained by recrys-
tallization from toluene-hexanes. Anal. Calcd for C37H53N2P3-
SRu‚2C4H8O: C, 60.32; H, 7.76; N, 3.13. Found: C, 60.17; H,
7.73; N, 3.19. 1H NMR (C6D6): δ 7.82 (dd, 2H, C6H4), 6.96 (dt,
2H, C6H4), 6.95 (br s, 4H, Me2C6H3), 6.86 (dd, 2H, C6H4), 6.66
(s, 2H, Me2C6H3), 6.39 (dt, 2H, C6H4), 2.23 (s, 12H, Me2C6H3),
1.11 (vt, 18H, PMe3), 0.53 (d, 9H, PMe3). 31P{1H} NMR
(C6D6): δ 2.2 (d, J ) 33.1 Hz, 2P), -12.9 (t, J ) 29.4 Hz, 1P).
P r ep a r a tion of [(P Me3)2(P h CN)Ru [Xy2NSN]] (3). To a
solution of 2‚(THF)2 (90 mg, 0.10 mmol) in toluene (5 mL) was
added benzonitrile (206 mg, 2.0 mmol), and the mixture was
stirred at room temperature for 18 h. Volatiles were removed
in vacuo, and the residue was recrystallized from boiling
acetone to give 3 as an orange crystalline solid. Yield: 38 mg,
49%. Anal. Calcd for C41H49N3P2SRu: C, 63.22; H, 6.34; N,
5.39. Found: C, 62.57; H, 6.39; N, 5.71. 1H NMR (C6D6): δ
7.39 (m, 1H, Ph), 7.37 (m, 2H, Ph), 7.34 (m, 2H, C6H4), 7.01
6.50 (dd, 2H, C6H4), 6.39 (s, 4H, Me2C6H3), 6.06 (dt, 2H, C6H4),
3
3.94 (m, 2H, RuNH2NH2), 2.91 (br t, J HH ) 4.4 Hz, 2H,
RuNH2NH2), 2.18 (br s, 12H, Me2C6H3), 1.29 (vt, 18H, PMe3).
31P{1H} NMR (CD2Cl2): δ 9.0 (s).
P r ep a r a tion of [(P Me3)2Ru (K2-(O,N)-P h C(O)dNNH2)-
(H[Xy2NSN])] (6). To a solution of 2‚(THF)2 (65 mg, 0.073
mmol) in toluene (5 mL) was added benzoylhydrazine (14 mg,
0.10 mmol), and the mixture was stirred at 60 °C for 2 days.
Volatiles were removed in vacuo, and the residue was recrys-
tallized from THF-hexanes to give 6 as yellow crystals.
Yield: 52 mg, 88%. Anal. Calcd for C41H52N4OP2SRu: C, 60.65;
1
H, 6.46; N, 6.90. Found: C, 60.94; H, 6.61; N, 7.24. H NMR
(CD2Cl2): δ 8.01 (br s, 1H, XyNH), 7.77 (m, 1H, C6H4), 7.67
(d, 2H, Ph), 7.32 (t, 1H, Ph), 7.25 (d, 2H, Ph), 7.24 (m, 2H,
C6H4), 6.92 (dd, 1H, C6H4), 6.81 (dt, 1H, C6H4), 6.68 (s, 1H,
Me2C6H3), 6.49 (dt, 1H, C6H4), 6.39 (br s, 2H, Me2C6H3), 6.30
(s, 1H, Me2C6H3), 6.17 (br s, 2H, Me2C6H3), 6.01 (dd, 1H, C6H4),
5.95 (dt, 1H, C6H4), 5.32 (m, 1H, NNH2), 4.95 (dd, 1H, NNH2),
2.31, 1.90 (br s, 3H each, Me2C6H3), 1.88 (s, 6H, Me2C6H3), 1.26,
1.17 (d, 9H each, PMe3). 31P{1H} (CD2Cl2): δ 17.7 (d, J ) 33.1
Hz), 12.4 (d, J ) 33.1 Hz).
Hyd r ogen a tion of Ben zon itr ile. A typical procedure for
the hydrogenation of benzonitrile is as follows. A THF solution

3904 Organometallics, Vol. 21, No. 19, 2002
Takemoto et al.
(5 mL) containing complex 1a (30 mg, 0.050 mmol), PCy3 (28
mg, 0.10 mmol), and benzonitrile (516 mg, 5.00 mmol) was
prepared in a Schlenk tube and then transferred to a 50 mL
stainless steel autoclave by syringe. The reactor was pressur-
ized with H2 (30 atm) at room temperature, and the reaction
mixture was heated at 80 °C with stirring for 18 h. After the
mixture was cooled to room temperature, hydrogen gas was
released and the products were analyzed by gas chromatog-
raphy.
(SHELXL97).21 All non-hydrogen atoms were refined with
anisotropic thermal parameters. All C-H hydrogen atoms
were placed at the calculated positions and treated as riding
models. The N-H hydrogen atoms in 6‚(n-C6H14
)0.5‚(cyclo-
C6H12 were found in the difference Fourier map and were
)
0.5
refined isotropically, while those in 5 were not found and were
not included in the calculation. For 1b‚(CH2Cl2)0.5, the two CF3
groups in one of the two Xyf substituents were disordered and
were modeled with six fluorine atoms (50% occupancy) for each
CF3 group. Details of the crystallographic parameters are
summarized in Table 5.
X-r ay Cr ystal Str u ctu r e Deter m in ation of 1b‚(CH2Cl2)0.5
,
2, 5, a n d 6‚(n -C6H14 0.5‚(cyclo-C6H12 0.5. Single crystals suit-
)
)
able for X-ray diffraction study were sealed in a glass capillary
and used for data collection. All measurements were performed
on a Rigaku MercuryCCD system. A total of 720 oscillation
images were collected at 20 °C with the exposure rate of 15 s
for each still. The data reductions were performed using
Rigaku CrystalClear program. Empirical absorption correction
and Lorentz-polarization corrections were applied.
Ack n ow led gm en t. This work was supported by the
J SPS FY2000 and FS2001 “Research for the Future
Program”. We thank Dr. Hidetake Seino at The Uni-
versity of Tokyo for assistance with FABMS analyses.
The structures were solved by direct method (SIR 92)20
and refined by full-matrix least-squares method on F2
Su p p or tin g In for m a tion Ava ila ble: Tables giving X-ray
crystallographic data for 1a , 1b‚(CH2Cl2)0.5, 2, 5, and 6‚(n-
C6H14)0.5‚(cyclo-C6H12)0.5. This material is available free of
charge via the Internet at http://pubs.acs.org.
(20) Altomare, A.; Cascarano, G.; Giacovazzo, C.; Guagliardia, A.
J . Appl. Crystallogr. 1993, 26, 343-350.
(21) Sheldrick, G. M. SHELXL-97, Program for Crystal Structure
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