New monocyclopentadienyl complexes of titanium(IV) and zirconium(IV) with chelating pyrimidinethiolate, oxypyrimidine, and oxypyridine ligands. Molecular structure of [Zr(η5-C5Me5) (η2-O,N-ON2C6H7)3]

Article abstract of DOI:10.1021/om990335t

New monocyclopentadienyl species of Ti(IV) and Zr(IV), namely Cp*MX(SR)₂, X = Cl, M = Zr 2, X = Ph, M = Zr 5, X = Me, M = Ti 6, bearing the pyrimidinethiolate ligand, SR, were prepared. In addition, tris-oxipyridine and -oxipyrimidine-containing zirconium complexes, Cp*Zr(OR)₃ 9 and 10, were also isolated. The dynamic behavior of some of them was studied by variable-temperature ¹H NMR spectroscopy. The molecular structure of 10 was also established by means of a X-ray diffraction study.

Full text of DOI:10.1021/om990335t

Organometallics 1999, 18, 5219-5224
5219
New Mon ocyclop en ta d ien yl Com p lexes of Tita n iu m (IV)
a n d Zir con iu m (IV) w ith Ch ela tin g P yr im id in eth iola te,
Oxyp yr im id in e, a n d Oxyp yr id in e Liga n d s. Molecu la r
Str u ctu r e of [Zr (η5-C5Me5)(η2-O,N-ON2C6H7)3]†
A. Antin˜olo,‡ F. Carrillo-Hermosilla,‡ A. E. Corrochano,‡ R. Fandos,§
J . Ferna´ndez-Baeza,‡ A. M. Rodr´ıguez,‡ M. J . Ruiz,§ and A. Otero*,‡
Departamento de Quı´mica Inorga´nica, Orga´nica y Bioquı´mica, Facultad de Ciencias
Quı´micas, Universidad de Castilla-La Mancha, Campus de Ciudad Real, 13701-Ciudad Real,
Spain, and Departamento de Quı´mica Inorga´nica, Orga´nica y Bioquı´mica, Facultad de
Ciencias del Medio Ambiente, Universidad de Castilla-La Mancha, Campus de Toledo,
45071-Toledo, Spain
Received May 6, 1999
New monocyclopentadienyl species of Ti(IV) and Zr(IV), namely Cp*MX(SR)2, X ) Cl, M
) Zr 2, X ) Ph, M ) Zr 5, X ) Me, M ) Ti 6, bearing the pyrimidinethiolate ligand, SR,
were prepared. In addition, tris-oxipyridine and -oxipyrimidine-containing zirconium
complexes, Cp*Zr(OR)3 9 and 10, were also isolated. The dynamic behavior of some of them
1
was studied by variable-temperature H NMR spectroscopy. The molecular structure of 10
was also established by means of a X-ray diffraction study.
In tr od u ction
ability to chelate and bridge transition metals, allowing
access to both mono- and oligonuclear products. In
addition, they contain functional groups common in
crude oils (thiolate-S and aromatic-N), and the pyrimi-
dine group is a constituent of nucleic acids.
In this area, we have recently described5 the prepara-
tion of a family of neutral and cationic pyrimidinethio-
late metallocene complexes. The chelating coordination
mode and reactivity observed encouraged us to prepare
analogous monocyclopentadienyl complexes of group 4
metals. The reported examples of this kind of thiolate
compound are very scarce;4 in fact, the first synthesis
of a monocyclopentadienyl zirconium thiolate was pub-
lished in 1995.6
In recent years there has been a major effort aimed
at investigating the chemistry of group 4 and 5 transi-
tion metals with chalcogenide ligands. This interest is
due to the important role that such compounds are
believed to play as intermediates in different reactions
such as desulfurization of organosulfur compounds1,2
and metal-catalyzed synthetic reactions involving C-S
bond cleavage and formation,3 and in this way, a
number of early transition metal thiolate complexes
have been prepared.4
Continued interest in complexes that incorporate
pyridinethiolate and pyrimidinethiolate is caused by
several desirable characteristics. Among these is their
This paper will focus on the synthesis and structural
details of new monocyclopentadienyl complexes of tita-
nium(IV) and zirconium(IV) bearing chelating pyrim-
idinethiolate ligands and analogous oxygen derivatives,
oxypyridine and oxypyrimidine ligands.
† Dedicated to Dr. J . Elguero on the occasion of his 65th birthday.
‡ Departamento de Qu´ımica Inorga´nica, Orga´nica y Bioqu´ımica,
Facultad de Ciencias Qu´ımicas, Campus de Ciudad Real.
§ Departamento de Qu´ımica Inorga´nica, Orga´nica y Bioqu´ımica,
Facultad de Ciencias del Medio Ambiente, Campus de Toledo.
(1) (a) Massoth, F. E. Adv. Catal. 1978, 27, 265. (b) Orr, W. L. Oil
Sand and Oil Shale Chemistry; Verlag Chemie: Weinheim, 1978; p
233. (c) Cyr, T. D.; Payzant, J . D.; Montgomery, D. S.; Srauzs, O. P.
Org. Geochem. 1986, 9, 139. (d) Nishikota, M. Energy Fuels 1988, 2,
214.
Resu lts a n d Discu ssion
Lithium thiolates have been shown to react with early
transition metal chlorides to give metal thiolates in good
yields.7 This methodology has been useful in the syn-
thesis of monocyclopentadienyl-containing bis-thiolate
zirconium complexes, such as Cp*ZrCl(SR)2 (Cp* ) η5-
C5Me5; SR ) C6H7N2S). In fact, the reaction of 1 equiv
of Cp*ZrCl3 (1) with 2 equiv of the appropriate lithium
thiolate in THF at room temperature affords the mono-
(2) (a) Sa´nchez-Delgado, R. A. J . Mol. Catal. 1994, 86, 287. (b)
Kwart, H.; Schuit, G. C. A.; Gates, B. C. J . Catal. 1980, 61, 128. (c)
Zaera, F.; Kollin, E. B.; Gland, J . L. Surf. Sci. 1987, 184, 75. (d) Eisch,
J . J .; Hallenbeck, L. E.; Han, K. L. J . Org. Chem. 1983, 48, 2963. (e)
Antebi, S.; Alper, H. Organometallics 1986, 5, 596. (f) Angelici, R. J .
Acc. Chem. Res. 1988, 21, 387. (g) Angelici, R. J . Coord. Chem. Rev.
1990, 105, 61. (h) Chen, J .; Angelici, R. J . Organometallics 1992, 11,
992. (i) Rauschfuss, T. B. Prog. Inorg. Chem. 1991, 39, 259.
(3) (a) Okamura, H.; Miura, M.; Takei, H. Tetrahedron Lett. 1979,
43. (b) Okamura, H.; Takei, H. Tetrahedron Lett. 1979, 3425. (c)
Murahashi, S.; Yamamura, M.; Yanagisawa, K.; Mita, N.; Kondo, K.
J . Org. Chem. 1979, 44, 2408. (d) Kosugi, M.; Shimizu, T.; Migita, T.
Chem. Lett. 1978, 13. (e) Hutchins, R. O.; Learn, K. J . Org. Chem.
1982, 48, 4380. (f) Wender, E.; Hanna, J . M.; Leftin, M. H.; Michelotti,
E. L.; Potts, K. T.; Usifer, D. J . Org. Chem. 1985, 50, 1125. (g) Tiecco,
M.; Testaferri, L.; Tingoli, M.; Chianelli, P.; Wenkert, E. Tetrahedron
Lett. 1982, 23, 4629. (h) Osakada, K.; Yamamoto, T.; Yamamoto, A.
Tetrahedron Lett. 1987, 27, 6321.
(4) Stephan, D. W.; Nadasdi, T. T. Coord. Chem. Rev. 1996, 147,
147.
(5) Fandos, R.; Lanfranchi, M.; Otero, A.; Pellinghelli, M. A.; Ruiz,
M. J .; Terreros, P. Organometallics 1996, 15, 4725.
(6) Heyn, R. H.; Stephan, D. W. Inorg. Chem. 1995, 34, 2804.
(7) Cardin, D. J .; Lappert, M. F.; Raston, C. L. Chemistry of
Organozirconium and Hafnium Compounds; Ellis Harwood Limited,
Halsted Press: New York, 1986.
10.1021/om990335t CCC: $18.00 © 1999 American Chemical Society
Publication on Web 11/10/1999

5220 Organometallics, Vol. 18, No. 25, 1999
Antin˜olo et al.
Sch em e 1
Sch em e 2
Sch em e 3
cyclopentadienyl bis-thiolate zirconium complex 2 in
63% yield (Scheme 1).
No isolable product was obtained from the reaction
between Cp*ZrCl3 and the lithium thiolate in a 1:1
molar ratio. Furthermore, reaction between Cp*ZrCl3
and LiSR in a 1:3 molar ratio affords the bis-thiolate
complex 2.
Complex 2 was isolated as an air-sensitive yellow
solid that is insoluble in alkanes but soluble in toluene
1
and THF. Complex 2 was characterized by H and 13C
1
NMR and IR spectroscopy. Their room-temperature H
#
Ta ble 1. Estim a ted ∆Gc Va lu es for F lu xion a l
NMR and 13C{1H} NMR (C6D6) spectra indicate that
both thiolate groups are inequivalent and fixed in a rigid
disposition where they act as bidentate ligands at this
temperature (see Experimental Section).
P r ocesses in Com p lex 6
#
Tc (K)
δν (Hz)
∆Gc (kcal‚mol-1
)
335
305
219
106.2
21.1
229.6
16.0(1)
15.5(2)
9.9(2)
Furthermore, it has been extensively described that
early transition metal alkyl complexes react with acidic
reagents, such as alcohols or mercaptans, to yield the
corresponding alkane and the alkoxide or thiolate
complexes, respectively. It has also been pointed out
that the probable mechanism for the protonolysis of the
carbon-metal bonds in these processes requires the
initial donation of an oxygen or sulfur lone pair of
electrons to the metal center.7 This methodology has
proven useful for the synthesis of monocyclopentadienyl-
containing alkanethiolate titanium and zirconium com-
pounds such as Cp*M(R)(SR)2. In this way, the reaction
of 4,6-dimethyl-2-mercaptopyrimidine with Cp*ZrPh3
(3) or with Cp*TiMe3 (4) in a 2:1 molar ratio at room
temperature affords complexes 5 and 6, respectively, as
shown in Scheme 1.
fluxional behavior may be occurring in the molecule.
This behavior is probably due to the interchange of the
positions of the nitrogen atoms of the pyrimidine groups
in the coordination sphere of the titanium atom by
rotation around the S-C bonds (see Scheme 2).
A variable-temperature H NMR study was carried
out. Scheme 3 shows the different situations that must
be considered.
1
1
When the H NMR spectrum was recorded at 183 K,
four different signals corresponding to the methyl
groups of the pyrimidine fragments were found, indicat-
ing that rotation around the S-C bond was hindered
for both thiolate ligands (Scheme 3, situation a). As the
temperature increases, rotation around the C-S bonds
becomes easier, and at temperatures above 219 K, only
three signals are observed for the methyl groups. One
signal integrates as six protons, indicating that while
one thiolate acts as a bidentate ligand, the other is
bonded to the metal center only by the sulfur atom. For
temperature values between 304 and 336 K, the spec-
trum shows only two methyl signals, each of which
integrates as six protons, and one of these signals is
broad (Scheme 3, situation b). Finally, above 335 K, a
single methyl peak was observed, and this corresponds
to free rotation of both ligands, which are now equiva-
lent (Scheme 3, situation c). Three different coalescence
temperatures at 219, 305, and 335 K were found. These
temperatures and the two site exchange equations8 can
be used to estimate the values of ∆G# for the different
exchange processes (Table 1).
The same reaction between 4,6-dimethyl-2-mercap-
topyrimidine and 3 or 4 in a 1:1 molar ratio gives an
intractable mixture of products, which was not charac-
terized. In addition, the reactions in a 3:1 molar ratio
afford complexes 5 and 6.
Complex 5 was isolated as a white air-sensitive solid,
which is virtually insoluble in pentane and partially
soluble in toluene and THF. The 1H and 13C NMR
spectra of complex 5 at room temperature are very
similar to those of complex 2 (see Experimental Section).
Complex 6 was obtained as a red air-sensitive solid that
is soluble in THF and toluene but virtually insoluble in
pentane. This compound has also been characterized by
1H and 13C NMR and IR spectroscopy (see Experimental
Section). The 1H NMR spectrum (toluene-d8) at room
temperature exhibits two signals at 1.97 and 2.33 ppm,
both of which integrate to six protons, and these
correspond to the methyl groups of the inequivalent
thiolate ligands. These resonances appear as a broad
signal and a sharp singlet, respectively, indicating that
Compound 6 reacts readily, in C6D6 in an NMR tube
at room temperature, with 2,6-dimethylphenyl isocya-
(8) Abrahams, R. J .; Fisher, J .; Loftus, P. Introduction to NMR
Spectroscopy; J ohn Wiley and Sons: New York, 1988.

Monocyclopentadienyl Complexes of Ti(IV) and Zr(IV)
Organometallics, Vol. 18, No. 25, 1999 5221
Sch em e 4
Sch em e 6
Sch em e 5
groups of the pyridine moiety (see Experimental Sec-
1
tion). A variable-temperature H NMR study was car-
1
ried out. When the H NMR spectrum was recorded at
193 K, three signals of equal intensity, each integrating
as three protons, were observed for the methyl groups
of the pyridine moieties, indicating that the three
oxypyridine ligands are not equivalent. Different struc-
tural situations could be considered, but on the basis of
the X-ray crystal structure data obtained for complex
10 (see below) a pentagonal bipyramidal geometry in
which the three groups behave as chelate O,N ligands
can be proposed (see Scheme 6).
When the temperature was increased to 223 K two
peaks coalesce and two signals were observed, indicating
that two groups could exchange their positions around
the metal center, probably through a rupture of the
metal-nitrogen bonds (see Scheme 6). This exchange
gives rise to two equivalent and one inequivalent
ligands. At 373 K, a single signal was clearly observed
for the methyl groups, and this is in accordance with
the fact that the third group would take part in the
exchange, giving rise to three equivalent groups (see
Scheme 6). A similar dynamic behavior was observed
for complex 10. However, plausible alternative mecha-
nisms for the interchange process that do not involve
the breaking of the metal-nitrogen bonds cannot be
definitively ruled out.
A single-crystal X-ray analysis of compound 10 was
carried out in order to provide precise structural details
of this compound and the related complex 9. The
structure of complex 10 is shown in Figure 1 together
with the atom-numbering scheme and selected bond
lengths and angles.
The Zr atom has a distorted pentagonal bipyramidal
geometry, with the Cp* ligand occupying an axial
coordination site. The other six sites are occupied by the
oxypyrimidine ligands in a chelate fashion. In this way,
a nitrogen atom of an oxypyrimidine ligand is almost
trans to the Cp* ligand, and the pentagonal base
appears to be constituted by the oxygen atom of the
same oxypyrimidine ligand and the other two hetero-
cyclic groups.
nide in a 1:1 ratio to give the corresponding η2-iminoacyl
complex 7 (Scheme 4) in almost quantitative yield. The
complex is extremely air-sensitive, and all attempts to
prepare and isolate it on a preparative scale were
unsuccessful.
1
The H and 13C NMR spectroscopic data point to an
η2-coordination of the iminoacyl ligand, while the thio-
lates act as monodentate ligands. This is in agreement
with the situation one would expect based on the litera-
ture precedents, which describe early transition metal
iminoacyl complexes to be normally stabilized by coor-
dination of the nitrogen atom to the metal center in an
η2-coordination mode.9 Accordingly, the 13C{1H} NMR
spectrum shows the signal due to the iminoacyl carbon
1
atom at 226.3 ppm,10 and the H NMR spectrum shows
that the four methyl groups in the pyrimidine moieties
are equivalent, which means that free rotation around
the C-S bonds occurs (see Experimental Section).
In a similar way, complexes analogous to 2, 5, and 6
were obtained when 6-methyl-2-hydroxypyridine (HOpy′)
or 2,4-dimethyl-6-hydroxypyrimidine (HOpm′) was re-
acted (Scheme 5) with Cp*ZrMe3 (8) in hexane at room
temperature. In these reactions the alkyl groups were
completely replaced by the hydroxy groups, even when
1:1 or 2:1 stoichiometries were used.
The complexes Cp*Zr(Opy′)3 (9) and Cp*Zr(Opm′)3
(10) were isolated as white air-sensitive solids; they are
sparingly soluble in alkanes but are soluble in toluene
or THF. These compounds have been also characterized
1
by H and 13C NMR and IR spectroscopy (see Experi-
mental Section). Their 1H NMR spectra at room tem-
perature exhibit broad signals for the pyridine or
pyrimidine moieties, indicating that some dynamic
process takes place in these molecules. Therefore, the
room-temperature 1H NMR (toluene-d8) spectrum of
compound 9 shows two broad peaks at 1.81 and 2.44
ppm in a 2:1 ratio, and these correspond to the methyl
The pentagonal bipyramidal geometry is distorted.
First, the Zr atom is out of the equatorial plane. This
can be explained on the basis of an O11-O13 contact
(9) Durfee, L. D.; Rothwell, I. P. Chem. Rev. 1988, 88, 1059.
(10) Martin, A.; Mena, M.; Pellinghelli, M. A.; Royo, P.; Serrano,
R.; Tiripicchio, A. J . Chem. Soc., Dalton Trans. 1993, 2117.

5222 Organometallics, Vol. 18, No. 25, 1999
Antin˜olo et al.
F igu r e 1. ORTEP drawing of complex 10, with the atomic
labeling scheme. The thermal ellipsoids are at the 30% level
of probability. Selected bond distances (Å) and angles (deg),
with esd’s in parentheses, for complex 10: Zr(1)-O(11)
2.162(6); Zr(1)-N(12) 2.337(7); Zr(1)-N(11) 2.409(6); O(11)-
C(11) 1.288(9); O(11)-Zr(1)-O(13) 73.1(2); N(11)-Zr(1)-
N(13) 150.1(2); O(11)-Zr(1)-N(11) 57.7(2); O(11)-C(11)-
N(11) 114.3(7).
F igu r e 2. Schematic drawing of complex 10, indicating
the three inequivalent oxypyrimidine ligands, with the
theoretical plane of symmetry: (a) front view; (b) top view;
the cyclopentadienyl ligand was omitted for clarity.
distance of 2.59 Å (sum of van der Waals radii ) 3.04
Å). In addition, there are two other intramolecular
contacts between O12 and N13 of 2.91 Å (sum of van
der Waals radii ) 3.10 Å), and N11 and N12 of 2.83 Å
(sum of van der Waals radii ) 3.16 Å). These contacts
are probably responsible for the deviation of the oxy-
pyrimidine ligand situated in the pseudoaxial position
and eliminates the theoretical symmetry plane (Figure
2). This distortion makes the three oxypyrimidine
ligands inequivalent around the Zr atom.
and pentane were distilled from sodium/potassium alloy. All
solvents were deoxygenated prior to use.
The following reagents were prepared by literature pro-
cedures: Cp*ZrCl3,11 Cp*ZrMe3,11 Cp*ZrPh3,11 Cp*TiCl3,12
Cp*TiMe3.13 2,6-Dimethylphenyl isocyanide was purchased
from Fluka, stored over molecular sieves, and deoxygenated
before use. Dimethyl-2-mercaptopyrimidine, 2-hydroxy-6-meth-
ylpyridine, and 2,4-dimethyl-6-hydroxypyrimidine were used
as received from Aldrich.
1H and 13C NMR spectra were obtained on a 300 Unity
Varian spectrometer. Trace amounts of protonated solvents
were used as references, and chemical shifts are reported in
parts per million relative to SiMe4. IR spectra were obtained
in the region 200-4000 cm-1 using a Perkin-Elmer 883
spectrophotometer.
Con clu d in g Rem a r k s
In this paper we have reported the synthesis of some
new titanium and zirconium monocyclopentadienyl-
containing complexes with two or three chelating pyri-
midinethiolate, oxypyrimidine, or oxypyridine ligands.
These compounds are prepared by halide or alkyl
displacement.
Whereas zirconium complexes 2 and 5, which bear
two thiolate ligands, are rigid in solution at room
temperature, analogous trisubstituted oxypyridine and
oxypyrimidine complexes 9 and 10, as well as titanium
complex 6, which all bear two thiolate ligands, show a
fluxional behavior in solution.
Syn th esis of Cp *Zr (Cl)(η2-SC6H7N2)2 (2). To a solution
of HS(C6H7N2) (0.22 g, 1.60 mmol) in 5 mL of THF was added
1 mL (1.60 mmol) of nBuLi (1.6 M hexane solution). The
mixture was stirred at room temperature for 30 min. The
solution was then cooled at -78 °C, and 0.27 g (0.80 mmol) of
Cp*ZrCl3 was added. The mixture was allowed to reach room
temperature and stirred for 1 h. The solvent was removed
under vacuum, the residue was extracted with toluene, and
after filtration, the toluene was evaporated and the yellow oil
washed with pentane to afford 0.27 g (63%) of a pale yellow
solid, which was characterized as 2: IR (Nujol/PET, cm-1) 1576
(s), 1529 (s), 1258 (s), 1205 (m), 678 (m), 360 (m), 209 (m); 1H
NMR (300 MHz, C6D6) δ 1.65 (s, 3H, CH3), 1.89 (s, 3H, CH3),
2.00 (s, 15H, Cp*), 2.01 (s, 3H, CH3), 2.35 (s, 3H, CH3), 5.69
(s, 1H, CH pyrimidine), 5.91 (s, 1H, CH pyrimidine); 13C{1H}
NMR (75 MHz, C6D6) δ 12.6 (Cp*), 20.9 (CH3), 23.6 (CH3), 23.8
(CH3), 24.1 (CH3), 114.9 (CH pyrimidine), 117.0 (CH pyrimi-
dine), 124.8 (Cp*), 161.5 (C-CH3), 165.0 (C-CH3), 168.8 (C-
CH3), 169.5 (C-CH3), 175.3 (C-S), 182.5 (C-S). Anal. Calcd
The molecular structure of 10, as determined by X-ray
diffraction studies, shows heptacoordination around the
zirconium atom with the three chelate heterocyclic
substituents in an asymmetric disposition.
We have also studied the reaction of Cp*Ti(Me)(η2-
SC6H7N2)3 (6) and 2,6-dimethylphenyl isocyanide, and
this process gives rise to the corresponding η2-iminoacyl
complex, as indicated by NMR data.
Exp er im en ta l Section
(11) Wolczanski, P. T.; Bercaw, J . E. Organometallics 1982, 1, 793.
(12) (a) Cardoso, A. M.; Clark, R. J . H.; Moorhouse, S. J . J . Chem.
Soc., Dalton Trans. 1980, 1156. (b) Hidalgo, G.; Mena, M.; Palacios,
F.; Royo, P.; Serrano, R. J . Organomet. Chem. 1988, 340, 37.
Gen er a l P r oced u r es. All reactions were carried out using
Schlenk techniques or a glovebox (model VAC HE-2). Hexane

Monocyclopentadienyl Complexes of Ti(IV) and Zr(IV)
Organometallics, Vol. 18, No. 25, 1999 5223
Ta ble 2. Cr ysta l Da ta a n d Str u ctu r e Refin em en t
for Com p lex 10
for C22H29N4ClS2Zr: C, 48.90; H, 5.41; N, 10.37. Found: C,
48.87; H, 5.45; N, 10.12.
Syn th esis of Cp *Zr (P h )(η2-SC6H7N2)2 (5). A mixture of
Cp*ZrPh3 (0.26 g, 0.57 mmol) and HS(C6H7N2) (0.16 g, 1.15
mmol) in 20 mL of pentane was stirred at room temperature
overnight. The white precipitate was separated by filtration,
washed twice with 5 mL of pentane, and vacuum-dried to yield
0.22 g (67%) of 2: IR (Nujol/PET, cm-1) 1600 (m), 1575 (s), 1525
empirical formula
fw
C28H36N6O3Zr
595.85
temperature
293(2) K
wavelength
0.71070 Å
cryst syst, space group
unit cell dimens
Triclinic, P1h
a ) 8.868(4) Å, R ) 100.11(4)°
b ) 11.022(6) Å, â ) 101.50(3)°
c ) 16.599(5) Å, γ ) 111.20(4)°
1426.8(11) Å3
1
(s), 1325 (s), 1258 (s), 1016 (m), 691 (m), 433 (m), 350 (s); H
NMR (300 MHz, C6D6) δ 1.82 (s, 3H, CH3), 1.89 (s, 15H, Cp*),
1.91 (s, 3H, CH3), 2.23 (s, 3H, CH3), 2.27 (s, 3H, CH3), 5.44 (s,
1H, CH pyrimidine), 5.65 (s, 1H, CH pyrimidine), 7.13-7.62
(m, 5H, Ph); 13C{1H} NMR (75 MHz, C6D6) δ 12.5 (Cp*), 23.67
(CH3), 23.71 (CH3), 23.88 (CH3), 23.89 (CH3), 115.1 (CH
pyrimidine), 117.2 (CH pyrimidine), 127.0 (Cp*), 123.8, 125.2,
128.5, 135.0 (Ph), 164.5 (C-CH3), 166.1 (C-CH3), 168.6 (C-
CH3), 168.8 (C-CH3), 176.5 (C-S), 180.0 (C-S). Anal. Calcd
for C28H34N4S2Zr: C, 57.79; H, 5.89; N, 9.62. Found: C, 57.82;
H, 5.90; N, 9.63.
volume
Z, calcd density
abs coeff
2, 1.387 g/cm3
4.25 cm-1
F(000)
620
cryst size
θ range for data
collection
0.4 × 0.3 × 0.2 mm
2.06-28.00°
index ranges
0 e h e 11, -14 e k e 13,
-1 e l e 21
6888/6888
no. of reflns
collected/unique
Syn th esis of Cp *Ti(Me)(η2-SC6H7N2)2 (6). A mixture of
Cp*TiMe3 (0.86 g, 3.76 mmol) and HS(C6H7N2) (1.05 g, 7.52
mmol) in 40 mL of toluene was stirred at room temperature
for 3 h. After filtration the solvent was evaporated and the
red oil was washed with pentane to afford 1.60 g (89%) of a
completeness to 2θ ) 28.00
no. of data/restraints/
params
100.0%
6888/0/344
goodness-of-fit on F2
final R indices [I > 2σ(I)]a
extinction coeff
1.022
R1 ) 0.1068, wR2 ) 0.2500
0.005(2)
red solid, which was characterized as 3: IR (Nujol/PET, cm-1
)
largest diff peak and hole
1.543 and -2.276 e Å-3
1620 (m), 1571 (s), 1520 (s), 1260 (s), 1010 (s), 648 (m), 356
1
-
Fc2)2]/
a
2
(m), 203 (m); H NMR (300 MHz, C6D6) δ 1.02 (s, 3H, CH3-
R1
)
∑||Fo|
-
|Fc||/∑|Fo|; wR2
)
[∑[w(Fo
∑[w(Fo2)2] ]
.
0.5
Ti), 1.92 (s, 15H, Cp*), 1.97 (s, broad, 6H, CH3), 2.33 (s, 6H,
CH3), 5.67 (s, 1H, CH pyrimidine), 5.78 (s, 1H, CH pyrimidine);
1
13C NMR (75 MHz, C6D6) δ 13.3 (q, J C-H ) 126.9 Hz, Cp*),
for 4 h. The white precipitate was separated by filtration,
washed twice with 10 mL of hexane, and vacuum-dried.
Recrystallization from dichloromethane/pentane afforded 0.32
g of 10 as white crystals (85%): IR (Nujol/PET, cm-1) 1657
(m), 1630 (m), 1551 (m), 1030 (m); 1H NMR (300 MHz, toluene-
d8) δ 1.84 (s, 3H, CH3 pyrimidine), 1.93 (s, 15H, Cp*), 2.01 (s,
6H, CH3 pyrimidine), 2.03 (s, 3H, CH3 pyrimidine), 2.69 (s,
6H, CH3 pyrimidine), 5.85 (s, 2H, CH pyrimidine), 5.91 (s, 1H,
CH pyrimidine); 13C{1H} NMR (75 MHz, toluene-d8) δ 11.11
(Cp*), 22.69, 23.02 (CH3 pyrimidine), 23.54, 24.19 (CH3 pyri-
midine), 103.28, 103.68 (C5 pyrimidine), 123.07 (Cp*), 162.05,
165.35 (C4 pyrimidine), 168.18, 169.24 (C2 pyrimidine), 176.58,
177.69 (C6 pyrimidine). Anal. Calcd for C28H36N6O3Zr: C,
56.44; H, 6.09; N, 14.10. Found: C, 56.48; H, 6.31; N, 14.32.
Str u ctu r e Deter m in a tion of Com p lex 10. Crystals of
complex 10 that were suitable for X-ray diffraction were
obtained by crystallization from toluene/hexane. A prismatic
crystal was selected and mounted on a fine glass fiber with
epoxy cement. The crystals were of poor quality and diffracted
rather weakly; unfortunately, no other crystals could be
obtained. Accurate unit-cell parameters were derived from the
least-squares fit of the angular setting of 25 high-order
reflections. The data collection was perfomed on a Nonius-
Mach3 diffractometer equipped with a graphite-monochro-
mated Mo KR radiation source (λ ) 0.7107 Å) using an ω/2θ
scan technique to a maximum value of 56°. The compound
crystallizes in the triclinic group P1h with Z ) 2. The cen-
trosymmetric alternative was initially assumed and later
confirmed by computationally stable refinement. There is one
molecule of 10 per asymmetric unit. Parameters for the
collection and refinement of diffraction data are contained in
Table 2. In addition to the usual corrections for Lorentz and
polarization effects, a semiempirical correction for absorption
correction was applied14 (maximum and minimum values of
the transmission factor were 1.00 and 0.58).
1
1
22.7 (q, J C-H ) 128.4 Hz, CH3), 23.4 (q, J C-H ) 127.4 Hz,
1
1
CH3), 24.0 (q, J C-H ) 127.4 Hz, CH3), 61.6 (q, J C-H ) 125.9
1
Hz, CH3-Ti), 114.5 (d, J C-H ) 164.7 Hz, CH pyrimidine),
1
117.5 (d, J C-H ) 166.7 Hz, CH pyrimidine), 126.5 (s, Cp*),
163.9 (s, C-CH3), 166.4 (s, C-CH3), 167.7 (s, C-CH3), 178.9
(s, C-S), 181.6 (s, C-S). Anal. Calcd for C23H32N4S2Ti: C,
57.97; H, 6.77; N, 11.76. Found: C, 57.23; H, 6.92; N, 11.57.
Syn th esis of Cp *Ti(η2-MeCNXylyl)(η1-SC6H7N2)2 (7). A
mixture of Cp*Ti(Me)(SC6H7N2)2 (0.03 g, 0.06 mmol) and 2,6-
dimethylphenyl isocyanide (0.01 g, 0.06 mmol) in 0.7 mL of
C6D6 was allowed to react at room temperature in an NMR
tube. The 1H and 13C{1H} NMR spectra were recorded, and
the product was identified as 5: 1H NMR (300 MHz, C6D6) δ
1.54 (s, 3H, CH3-Ti), 1.95 (s, 15H, Cp*), 2.01 (s, 6H, CH3),
2.09 (s, 12H, CH3), 5.93 (s, 2H, CH pyrimidine), 6.52-6.83 (m,
3H, xylyl); 13C{1H} NMR (75 MHz, C6D6) δ 12.3 (Cp*), 18.6
(CH3), 19.9 (CH3), 23.9 (CH3), 114.1 (CH pyrimidine), 124.9
(Cp*), 126.0, 127.7, 128.5 (CH, xylyl), 132.4 (C-CH3, xylyl),
144.3 (C-CN, xylyl), 166.4 (C-CH3, pyrimidine), 179.7 (C-
S), 226.3 (CdN).
Syn th esis of Cp *Zr (η2-O,N-ONC6H6)3 (9). A mixture of
Cp*ZrMe3 (0.25 g, 0.92 mmol) and HO(NC6H6) (0.26 g, 2.35
mmol) in 10 mL of hexane was stirred at room temperature
for 4 h. The white precipitate was separated by filtration,
washed twice with 10 mL of hexane, and vacuum-dried.
Recrystallization from dichloromethane/pentane yielded white
crystals of 9 (0.40 g, 80%): IR (Nujol/PET, cm-1) 1650 (m),
1617 (m), 1584 (m), 1030 (m); 1H NMR (300 MHz, toluene-d8)
δ 1.81 (s, 3H, CH3 pyridine), 2.04 (s, 15H, Cp*), 2.44 (s, 6H,
3
CH3 pyridine), 5.61 (d, 1H, J ) 7.00 Hz, CH3or5), 5.95 (d, 2H,
3
3J ) 7.00 Hz, CH3or5), 6.14 (d, 3H, J ) 8.14 Hz, CH3or5), 6.76
3
3
3
(pt, 1H, J ) 8.14 Hz, J ) 7.00 Hz, CH4), 6.90 (pt, 2H, J )
3
8.14 Hz, J ) 7.00 Hz, CH4); 13C{1H} NMR (75 MHz, toluene-
d8) δ 11.29 (Cp*), 21.33, 20.43 (CH3 pyridine), 107.76 (CH5
pyridine), 110.91, 111.65 (CH3 pyridine), 121.88 (Cp*), 140.04,
140.31 (CH4 pyridine), 152.13, 155.05 (C6 pyridine), 173.55,
173.97 (C2 pyridine). Anal. Calcd for C28H33N3O3Zr: C, 61.06;
H, 6.04; N, 7.63. Found: C, 61.23; H, 6.18; N, 7.72.
The structure was solved using direct methods15 and refined
first isotropically by full-matrix least-squares using the
SHELXL-9716 program and then anisotropically by blocked
(13) Mena, M.; Pellinghelli, M. A.; Royo, P.; Serrano, R.; Tiripicchio,
A. J . Chem. Soc., Chem. Commun. 1986, 1118.
(14) North, A. C. T.; Phillips, D. C.; Mathews, F. S. Acta Crystallogr.
1968, A24, 351.
Syn th esis of Cp *Zr (η2-O,N-ON2C6H7)3 (10). A mixture of
Cp*ZrMe3 (0.18 g, 0.92 mmol) and HO(N2C6H7) (0.22 g, 1.80
mmol) in 10 mL of hexane was stirred at room temperature

5224 Organometallics, Vol. 18, No. 25, 1999
Antin˜olo et al.
full-matrix least-squares for all the non-hydrogen atoms. The
hydrogen atoms were included in calculated positions and
refined “riding” on their parent carbon atoms. The final atomic
coordinates for 10 are provided in the Supporting Information.
senjanza SÄ uperior e Investigacio´n C´ıentifica (Grant No.
PB95-0023-C01-C02).
Su p p or tin g In for m a tion Ava ila ble: For 10, all crystal-
lographic data (Table SI), final atomic coordinates for the non-
hydrogen atoms (Table SII), bond lengths and angles (Table
SIII), anisotropic displacement parameters (Table SIV), final
atomic coordinates for the hydrogen atoms (Table SV), inter-
molecular contacts (Table SVI), and possible hydrogen bonds
(Table SVII). This material is available free of charge via the
Internet at http://pubs.acs.org.
Ack n ow led gm en t. We gratefully acknowledge fi-
nancial support from the Direccio´n General de In-
(15) Altomare, A.; Cascarano, G.; Giacovazzo, C.; Guagliardi, A.;
Burla, M. C.; Polidori, G.; Camalli, M. J . Appl. Crystallogr. 1994, 435-
436.
(16) Sheldrick, G. M. Program for the Refinement of Crystal Struc-
tures from Diffraction Data; University of Go¨ttingen: Go¨ttingen,
Germany, 1997.
OM990335T