Synthesis and characterization of some zirconium and hafnium complexes with a phosphide-pendant cyclopentadienyl ligand

Article abstract of DOI:10.1021/om020916+

Synthesis of some Zr and Hf complexes with a phosphide-pendant cyclopentadienyl ligand was attempted via alkylation (tribenzylation, triallylation, or monotritylation) of the secondary phosphine-pendant trichloride complex [{η⁵-C₅H₄(CH₂)₂P(H)Me s-κP}MCl₃(tht)] (Zr-1, Hf-1; Mes = 2,4,6-trimethylphenyl; tht = tetrahydrothiophene). The phosphide-pendant dibenzyl complex [{η⁵-C₅H₄(CH₂)₂PMes- κP}M(CH₂Ph)₂] (Zr-5, Hf-5) and the phosphidependant diallyl complex [{η⁵-C₅H₄(CH₂)₂PMes- κP}M(allyl)₂] (Zr-7, Hf-7) were successfully prepared through tribenzylation followed by thermolysis and through triallylation, respectively, of Zr-1 or Hf-1. The phosphide-pendant dichloride complex [{η⁵-C₅H₄(CH₂)₂PMes κP}MCl₂(N-methylimidazole)₂] (Zr-13, Hf-13) was also obtained through monotritylation of Zr-1 or Hf-1 followed by the treatment with N-methylimidazole, and the X-ray crystal structure of Zr-13 was determined. In addition, the allyl-chloride exchange reaction between 1 equiv of Hf-1 and 2 equiv of Hf-7 gave the unstable phosphide-pendant monoallyl monochloride Hf complex [{η⁵-C₅H₄(CH₂)₂PMes- κP}HfCl(allyl)] (Hf-8), which was characterized as its derivatives [{η⁵-C₅H₄(CH₂)₂PMes- κP}Hf(f)(allyl)] (Y = C₆F₅, Hf-14; Y = NPh₂, Hf-15; Y = NEt₂, Hf-16). It is proposed that the η³-alkyl-like ligand (benzyl, allyl, or trityl) in the secondary phosphine-pendant complex serves as an effective H-abstracting group to generate the corresponding phosphide-pendant complex with liberation of the alkyl-H coupling product.

Full text of DOI:10.1021/om020916+

1096
Organometallics 2003, 22, 1096-1105
Syn th esis a n d Ch a r a cter iza tion of Som e Zir con iu m a n d
Ha fn iu m Com p lexes w ith a P h osp h id e-P en d a n t
Cyclop en ta d ien yl Liga n d
Takeshi Ishiyama,† Tsutomu Mizuta,† Katsuhiko Miyoshi,*,† and
Hiroshi Nakazawa*,‡
Department of Chemistry, Graduate School of Science, Hiroshima University,
Higashi-Hiroshima 739-8526, J apan, and Department of Chemistry, Graduate School of
Science, Osaka City University, Sumiyoshi-ku, Osaka 558-8585, J apan
Received November 5, 2002
Synthesis of some Zr and Hf complexes with a phosphide-pendant cyclopentadienyl ligand
was attempted via alkylation (tribenzylation, triallylation, or monotritylation) of the
secondary phosphine-pendant trichloride complex [{η5-C5H4(CH2)2P(H)Mes-κP}MCl3(tht)] (Zr -
1, Hf-1; Mes ) 2,4,6-trimethylphenyl; tht ) tetrahydrothiophene). The phosphide-pendant
dibenzyl complex [{η5-C5H4(CH2)2PMes-κP}M(CH2Ph)2] (Zr -5, Hf-5) and the phosphide-
pendant diallyl complex [{η5-C5H4(CH2)2PMes-κP}M(allyl)2] (Zr -7, Hf-7) were successfully
prepared through tribenzylation followed by thermolysis and through triallylation, respec-
tively, of Zr -1 or Hf-1. The phosphide-pendant dichloride complex [{η5-C5H4(CH2)2PMes-
κP}MCl2(N-methylimidazole)2] (Zr -13, Hf-13) was also obtained through monotritylation of
Zr -1 or Hf-1 followed by the treatment with N-methylimidazole, and the X-ray crystal
structure of Zr -13 was determined. In addition, the allyl-chloride exchange reaction between
1 equiv of Hf-1 and 2 equiv of Hf-7 gave the unstable phosphide-pendant monoallyl
monochloride Hf complex [{η5-C5H4(CH2)2PMes-κP}HfCl(allyl)] (Hf-8), which was character-
ized as its derivatives [{η5-C5H4(CH2)2PMes-κP}Hf(Y)(allyl)] (Y ) C6F5, Hf-14; Y ) NPh2,
Hf-15; Y ) NEt2, Hf-16). It is proposed that the η3-alkyl-like ligand (benzyl, allyl, or trityl)
in the secondary phosphine-pendant complex serves as an effective H-abstracting group to
generate the corresponding phosphide-pendant complex with liberation of the alkyl-H
coupling product.
In tr od u ction
C4d) of the amide-pendant cyclopentadienyl complexes
[(η5-C5Me4SiMe2NtBu-κN)TiL2] (L ) Cl, alkyl group)
called constrained-geometry catalysts (CGC)6 (D), which
are effective in olefin copolymerization (Chart 1), be-
The chemistry of transition metal (M) compounds
having covalent bonds with heteroatom ligands (E) is
an interesting subject, since they have the potential to
exhibit novel reactivities which arise from their unique
M-E bonds.1 Additionally, such heteroatom ligands
often play a subtle role as an ancillary ligand to control
the reactivities, in particular for the early transition
metal complexes, which often survive as a less-than-18
electron species. Most of the early transition metal
complexes reported so far have covalent bonds to hard
heteroligands such as alkoxy and dialkylamide groups.
They obey the HSAB principle, are relatively stable, and
so are amenable to detailed studies. In contrast, less
common are early transition metal complexes with soft
ligands, especially phosphide ligands, which are phos-
phorus analogues of hard amide ligands.2-5 These
complexes are antagonistic to the HSAB principle, often
have difficulties in preparation, and so have not yet been
studied fully. Recently, there has been a growing
interest in the phosphide analogues (A,3f,h B,3f-h and
(2) For reviews and examples of phosphide group 4 metallocene
complexes: (a) Hey-Hawkins, E. Chem. Rev. 1994, 94, 1661, and
references therein. (b) Hey-Hawkins, E. In Comprehensive Organo-
metallic Chemistry II; Abel, E. W., Stone, F. G. A., Wilkinson, G., Eds.;
Pergamon: Oxford, U.K., 1995; Vol. 4, pp 501-542. (c) Stephan, D.
W. Angew. Chem., Int. Ed. 2000, 39, 314. (d) Issleib, K.; Ha¨ckert, H.
Z. Naturforsch. Teil B 1966, 21, 519. (e) Chiang, M. Y.; Gambarotta,
S.; Bolhuis, F. Organometallics 1988, 7, 1864. (f) Ho, J .; Stephan, D.
W. Organometallics 1991, 10, 3001. (g) Nielsen-Marsh, S.; Crowte, R.
J .; Edwards, P. G. J . Chem. Soc., Chem. Commun. 1992, 699. (h) Ho,
J .; Stephan, D. W. Organometallics 1992, 11, 1014. (i) Ho, J .; Hou, Z.;
Drake, R. J .; Stephan, D. W. Organometallics 1993, 12, 3145. (j) Ko¨pf,
H.; Richtering, V. J . Organomet. Chem. 1988, 346, 355. (k) Hey, E. J .
Organomet. Chem. 1989, 378, 375. (l) Vaughan, G. A.; Hillhouse G.
L.; Rheingold, A. L. Organometallics 1989, 8, 1760. (m) Arif, A. M.;
Cowley, A. H.; Nunn, C. M.; Pakulski, M. J . Chem. Soc., Chem.
Commun. 1987, 994. (n) Hey, E.; Lappert, M. F.; Atwood, J . L.; Bott,
S. G. Polyhedron 1988, 7, 2083.
(3) For examples of phosphide group 4 nonmetallocene complexes:
(a) Baker, R. T.; Krusic, P. J .; Tulip, T. H.; Calabrese, J . C.; Wreford,
S. S. J . Am. Chem. Soc. 1983, 105, 6763. (b) Danopoulos, A. A.;
Edwards, P. G.; Harman, M.; Hursthouse, M. B.; Parry, J . S. J . Chem.
Soc., Dalton Trans. 1994, 977. (c) Roddick, D. M.; Santarsiero, B. D.;
Bercaw, J . E. J . Am. Chem. Soc. 1985, 107, 4670. (d) Frenzel, C.; Hey-
Hawkins, E.; Mu¨ller, U.; Strenger, I. Z. Anorg. Allg. Chem. 1997, 623,
277. (e) Firth, A. V.; Stephan, D. W. Inorg. Chem. 1998, 37, 4732. (f)
Kunz, K.; Erker, G.; Do¨ring, S.; Fro¨hlich, R.; Kehr, G. J . Am. Chem.
Soc. 2001, 123, 6181. (g) Schottek, J .; Erker, G.; Kunz, K.; Doering, S.
PCT Int. Appl. 2001, p 69. (h) Altenhoff, G.; Bredeau, S.; Erker, G.;
Kehr, G.; Kataeva, O.; Fro¨hlich, R. Organometallics 2002, 21, 4084.
(i) Driess, M.; Aust, J .; Merz, K. Eur. J . Inorg. Chem. 2002, 2961.
* To whom correspondence should be addressed. E-mail: kmiyoshi@
sci.hiroshima-u.ac.jp; nakazawa@sci.osaka-cu.ac.jp.
† Hiroshima University.
‡ Osaka City University.
(1) Beller, M.; Bolm, C. Transition Metals for Organic Synthesis;
Wiley-VCH: Weinheim, 1998; Vol. 2.
10.1021/om020916+ CCC: $25.00 © 2003 American Chemical Society
Publication on Web 01/28/2003

Zirconium and Hafnium Complexes
Organometallics, Vol. 22, No. 5, 2003 1097
Ch a r t 1
Sch em e 1
cause such phosphide complexes are expected to have
unique reactivities based on the M-P covalent bonds.
We report here the synthesis and the characterization
of the dialkyl (benzyl and allyl) (E) and dichloride (F )
complexes of Zr and Hf with an ethylene-linked phos-
phide-cyclopentadienyl ligand and some related com-
plexes.
Sch em e 2
Resu lts a n d Discu ssion
Although the first phosphide complex of a group 4
transition metal has been reported by Issleib et al. in
1966,2d the synthetic methods have not yet been estab-
lished enough to obtain various phosphide complexes
for the purpose. Most of the phosphide complexes
reported for group 4 transition metals are limited to bis-
(cyclopentadienyl) compounds,2 and there are only a few
reports on nonmetallocene type phosphide complexes.3
Most of the synthetic methods reported are classified
into three groups;2a-c (Scheme 1) (i) the salt-elimination
reaction of a group 4 transition metal chloride complex
(LmMCl) with an alkali-metal phosphide (M′PHnR2-n
,
plex. However, the reaction of MCl4 (M ) Zr, Hf) with
the dilithio ligand Li2C5H4(CH2)2PMes (Mes ) 2,4,6-
trimethylphenyl) did not give any products of the [{η5-
C5H4(CH2)2PMes-κP}MCl2] type, in accordance with the
results obtained recently by Hey-Hawkins et al. and
Erker et al. in the similar reactions of ZrCl4 with Li2C5-
Me4SiMe2PR (R ) Mes, Cy).3h,7d
Next, we focused on method (iii), since the starting
alkyl complexes were readily available. The synthetic
route adopted consists of two steps (Scheme 2), i.e.,
preparation of a trichloride complex with a secondary
phosphine-pendant cyclopentadienyl ligand7 and its
subsequent alkylation leading to the desired phosphide
complex with liberation of a coupling product RH. The
synthesis of the secondary phosphine-pendant trichlo-
ride complexes [{η5-C5H4(CH2)2P(H)Mes-κP}MCl3(tht)]
(Zr -1, Hf-1; tht ) tetrahydrothiophene) has been re-
ported in our previous paper.7e
n ) 0, 1), (ii) the oxidative addition of a P-H-function-
alized phosphine PHnR3-n (n ) 1, 2, 3) to a divalent
metallocene complex,2e-i and (iii) the reaction of a
metallocene dialkyl complex with a P-H-functionalized
diphosphine (1,2-(PHPh)2C6H4 or 1,2-(PH2)2C6H4)2j-k or
the similar reaction of a hydride or an amide complex
with a P-H-functionalized phosphine.2i,l,3i The phos-
phide complexes have been prepared almost exclusively
by the first salt-elimination reaction (i). So, we at first
applied the conventional method (i) to the preparation
of the desired phosphide-pendant cyclopentadienyl com-
(4) For examples of phosphide group 3 transition metal complexes:
(a) Cendrowski-Guillaume, S. M.; Ephritikhine, M. J . Organomet.
Chem. 1999, 577, 161. (b) Clegg, W.; Izod, K.; Liddle, S. T. J .
Organomet. Chem. 2000, 613, 128. (c) Clegg, W.; Izod, K.; Liddle, S.
T.; O’Shaughnessy, P.; Sheffield, J . M. Organometallics 2000, 19, 2090.
(d) Tardif, O.; Hou, Z.; Nishiura, M.; Koizumi, T.; Wakatsuki, Y.
Organometallics 2001, 20, 4565.
(5) For examples of phosphide group 5 transition metal complexes:
(a) Domaille, P. J .; Foxman, B. M.; McNeese, T. J .; Wreford, S. S. J .
Am. Chem. Soc. 1980, 102, 4114. (b) Baker, R. T.; Calabrese, J . C.;
Harlow, R. L.; Williams, I. D. Organometallics 1993, 12, 830. (c)
Alcalde, M. I.; Mata, J .; Go`mez, M.; Royo, P.; Sa´nchez, F. J . Organomet.
Chem. 1995, 492, 151. (d) Nikonov, G. I.; Kuzmina, L. G.; Mountford,
P.; Lemenovskii, D. A. Organometallics 1995, 14, 3588. (e) Hadi, G.
A. A.; Fromm, K.; Blaurock, S.; J elonek, S.; Hey-Hawkins, E. Polyhe-
dron 1997, 16, 721.
(7) For examples of related complexes having phosphine-pendant
cyclopentadienyl ligands: (a) Butenscho¨n, H. Chem. Rev. 2000, 100,
1527, and references therein. (b) Krut’ko, D. P.; Borzov, M. V.; Veksler,
E. N.; Churakov, A. V.; Howard, J . A. K. Polyhedron 1998, 17, 3889.
(c) Koch, T.; Hey-Hawkins, E. Polyhedron 1999, 18, 2113. (d) Koch,
T.; Blaurock, S.; Somoza, F. B., J r.; Voigt, A.; Kirmse, R.; Hey-Hawkins,
E. Organometallics 2000, 19, 2556. (e) Ishiyama, T.; Nakazawa, H.;
Miyoshi, K. J . Organomet. Chem. 2002, 648, 231. (f) Ho¨cher, T.;
Blaurock, S.; Hey-Hawkins, E. Eur. J . Inorg. Chem. 2002, 1174.
(6) McKnight, A. L.; Waymouth, R. M. Chem. Rev. 1998, 98, 2587,
and references therein.

1098 Organometallics, Vol. 22, No. 5, 2003
Ishiyama et al.
Sch em e 3
Sch em e 4
Tr ia lk yla tion of th e Secon d a r y P h osp h in e Tr i-
ch lor id e Com p lex. The secondary phosphine-pendant
trichloride complex (Zr -1, Hf-1) was subjected to tri-
alkylation and triarylation. First, Zr -1 or Hf-1 was
allowed to react with 1.5 M MgMe2 or MgEt2 in ether,
but some complicated reactions took place to give
intractable products. Next, we used bulkier alkylation
and arylation reagents such as LiCH2SiMe3, Mg(CH2-
Ph)2(thf)2, and Mg(p-C6H4Me)2(1,4-dioxane)x (Scheme 3).
The reaction with 3 equiv of LiCH2SiMe3 or 1.5 M
Mg(CH2Ph)2(thf)2 proceeded cleanly, in contrast with
that with MgMe2 or MgEt2, to give a brown, oily
complex. In the 31P NMR spectra without proton ir-
radiation, the four products commonly showed a doublet
at -86 to -87 ppm (J PH ) 215-218 Hz), which is close
in chemical shift to that of the metal-free secondary
phosphine-pendant cyclopentadienyl compound Me3-
SiC5H4(CH2)2P(H)Mes (-85.7 ppm (J PH ) 218 Hz),
-86.0 ppm (J PH ) 217 Hz)).7e This suggests that the
secondary phosphine-pendant is not coordinated to the
metal center in any of the four products. On the basis
reaction except decomposition did not occur, probably
because the bulky trimethylsilylmethyl groups pre-
vented the secondary phosphine from approaching the
metal center. In contrast, the tribenzyl complex (Zr -3,
Hf-3) successfully afforded the dibenzyl phosphide
complex (Zr -5, Hf-5) with liberation of PhCH3 in
benzene or toluene at 80 °C (Scheme 4). The thermolysis
in C6D6 was monitored by the 31P and H NMR spectra.
1
In the 31P NMR spectrum without proton irradiation, a
singlet at 126.0 ppm for Zr -5 and at 111.2 ppm for Hf-5
newly appeared at the expense of a doublet due to the
starting complex (-86.9 ppm (J PH ) 215 Hz) for Zr -3
and -86.8 ppm (J PH ) 215 Hz) for Hf-3). The spectral
change for the Zr complex was completed within 20 min,
and that for the Hf complex was accomplished after 4
h. These 31P NMR data indicate the formation of the
M-P covalent bond with the P-H bond instead lost. In
1
of the H, 13C{1H}, and 31P NMR spectra, the products
were identified as tris(trimethylsilylmethyl) complexes
(Zr -2, Hf-2) and tribenzyl complexes (Zr -3, Hf-3), with
the secondary phosphine-pendant freed from the metal
center. The tribenzyl complex (Zr -3, Hf-3) decomposed
slowly in solution when it was concentrated at room
temperature, to afford intractable complexes.
1
the H NMR spectrum, a doublet of multiplets due to
the P-H proton of the starting complex (4.45 ppm for
Zr -3 and 4.39 ppm for Hf-3) disappeared and signals
assignable to toluene appeared (7.13-7.04 ppm (5H)
and 2.16 ppm (3H)). The methylene protons of the
benzyl groups, which had appeared as a singlet at 1.63
ppm (6H) for Zr -3 and at 1.72 ppm (6H) for Hf-3, shifted
to 2.23 ppm (4H) for Zr -5 and to 2.35 ppm (4H) for Hf-
5. These 1H NMR data are consistent with nearly
quantitative formation of the dibenzyl phosphide com-
plex (Zr -5, Hf-5) together with an equimolar amount
of toluene. Zr -5 and Hf-5 decomposed slowly in solution
and could not be isolated as a solid. The thermolysis of
the tri(p-C6H4Me) Hf complex (Hf-4) was also examined
in toluene, but it led only to decomposition even at 40
°C.
The above results prompted us to seek other trialky-
lation reagents to afford isolable phosphide complexes,
and it was found that triallylation was particularly
effective (Scheme 5). The reaction of Zr -1 or Hf-1 with
3 equiv of (allyl)MgCl in ether/THF at room temperature
resulted in direct and almost quantitative formation of
the isolable diallyl phosphide complex [{η5-C5H4(CH2)2-
PMes-κP}M(allyl)2] (Zr -7, 79%; Hf-7, 89%). In this
reaction, the triallyl secondary phosphine-pendant com-
plex [{η5-C5H4(CH2)2P(H)Mes}M(allyl)3] (Zr -6, Hf-6)
corresponding to Zr -3 or Hf-3 in Scheme 4 was probably
once formed, but it was immediately converted into the
diallyl phosphide complex with elimination of propene
even at room temperature. The 1H, 13C{1H}, and 31P
The triarylation reaction of Hf-1 with 1.5 M Mg(p-
C6H4Me)2(1,4-dioxane)x (Scheme 3) gave a yellow pow-
1
der, which was identified by the H, 13C{1H}, and 31P
NMR spectra as the corresponding secondary phos-
phine-pendant tri(p-C6H4Me) Hf complex (Hf-4). In
contrast, the similar triarylation of Zr -1 led to compli-
cated reactions, giving no desired tri(p-C6H4Me) Zr
complex. In the 31P NMR spectrum under off-resonance
conditions, Hf-4 showed a broad doublet at -67.9 ppm
(J PH ) 243 Hz) at 25 °C in toluene. With lowering the
temperature, the signal became split; at -80 °C, Hf-4
showed two broad doublets at -21.0 ppm (J PH ) 314
Hz) and -84.6 ppm (J PH ) 211 Hz). The former is close
in chemical shift to that of Hf-1, having a definite Hf-
P-H bond (-18.8 ppm (J PH ) 333 Hz), -19.1 ppm (J PH
) 329 Hz)), and the latter is close to that of the free
secondary phosphine ligand (vide supra).7e The variable-
temperature 31P NMR spectra suggest that Hf-4 exists
as a dynamic mixture of the secondary phosphine-
coordinated and -uncoordinated species in toluene.
Next, we attempted to convert the trialkyl complexes
thus obtained (Zr -2, Hf-2, Zr -3, Hf-3) into the corre-
sponding phosphide complexes by thermolysis. The tris-
(trimethylsilylmethyl) complex (Zr -2, Hf-2) was heated
at 80 °C for several days in toluene. However, any

Zirconium and Hafnium Complexes
Organometallics, Vol. 22, No. 5, 2003 1099
Sch em e 5
Sch em e 6. P r esu m ed Allyl-Ch lor id e Exch a n ge
Rea ction betw een 2 equ iv of M-1 a n d 1 equ iv of
M-7 (M ) Zr , Hf)
NMR spectra observed are all consistent with the
formation of the diallyl phosphide complex. The 31P
NMR spectrum without proton irradiation showed a
singlet at 147.4 ppm for Zr -7 and at 118.8 ppm for Hf-
7, which is in a reasonable range as judged from that
of the dibenzyl phosphide complex (Zr -5, Hf-5) (vide
1
supra). In the H NMR spectrum, the two allyl groups
were observed as a multiplet due to the CH group
(5.37-5.29 ppm for Zr -7 and 5.47-5.35 ppm for Hf-7)
and as two doublets due to the CH2 group (2.85 ppm
(J HH ) 12.6 Hz) and 2.84 ppm (J HH ) 12.3 Hz) for Zr -
7, and 2.76 ppm (J HH ) 12.5 Hz) and 2.75 ppm (J HH
)
Sch em e 7. Allyl-Ch lor id e Exch a n ge Rea ction
betw een 1 equ iv of Hf-1 a n d 2 equ iv of Hf-7
12.3 Hz) for Hf-7), indicating that the allyl groups are
coordinated to the metal center with an η3-mode on the
NMR time scale.8,9a,b Unfortunately, these diallyl com-
plexes did not grow to be crystals suitable for single-
crystal X-ray analysis. Zr -7 and H f-7 (and Zr -5 and
Hf-5 as well, though unstable and characterized by the
1H and 31P NMR spectra only) are rare examples of half-
sandwich type phosphide complexes of group 4 transi-
tion metals.3c-i
Mon oa llyla tion of th e Secon d a r y P h osp h in e
Tr ich lor id e Com p lex. It was found above that the
allyl group present in the precursor secondary phos-
phine-pendant complex (Zr -6, Hf-6) was effectively
eliminated as propene to leave the corresponding phos-
phide complex (Zr -7, Hf-7). However, the complex Zr -7
or Hf-7 thus obtained has two extra allyl groups
indifferent to the elimination. So, our synthetic interest
prompted us to prepare the dichloride phosphide com-
plex via the monoallyl dichloride complex having a
PHMes moiety as a pendant, since the dichloride
phosphide complex is expected to be a useful precursor
of several kinds of related phosphide derivatives.
To prepare the monoallyl dichloride secondary phos-
phine-pendant complex, we took two synthetic routes,
one of which was the cross reaction,9a,c i.e., the ligand
exchange between 2 equiv of the trichloride secondary
phosphine complex (Zr -1, Hf-1) and 1 equiv of the diallyl
phosphide complex (Zr -7, Hf-7) (Scheme 6), and the
other of which was the reaction of the secondary
phosphine trichloride complex (Zr -1, Hf-1) with 1 equiv
of (allyl)MgCl.
(Zr -10, Hf-10) nor its precursor complex (Zr -9, Hf-9)
predicted in Scheme 6, which was tentatively presumed,
was obtained with only intractable products formed,
probably because Zr -10 or Hf-10 was too labile to
isolate. Then, we altered the target complex to the
monoallyl monochloride phosphide complex (Zr -8, Hf-
8), which might be isolated because the corresponding
diallyl complex (Zr -7, Hf-7) was stable enough. For this
purpose, the mixing ratio of the starting complexes was
changed to M-1:M-7 ) 1:2 (M ) Zr, Hf) so as to enhance
the formation of the target complex (Zr -8, Hf-8) (Scheme
7). Under these conditions, the exchange reaction with
the Zr complexes, however, led to intractable products
again. On the other hand, the similar reaction with the
Hf complexes did yield the target complex Hf-8 quan-
titatively, though fairly unstable. In the 31P NMR
spectrum without proton irradiation, the reaction mix-
ture showed a singlet at 151.0 ppm due to Hf-8 at the
expense of the signals due to the starting complexes
Hf-1 and Hf-7 (vide supra). We propose the mechanism
of this reaction as shown in Scheme 7; the reaction
involves not only the direct formation of Hf-8 but also
First, the exchange reaction was conducted in toluene,
but neither the desired dichloride phosphide complex
(8) Becconsall, J . K.; J ob, B. E.; O’Brien, S. J . Chem. Soc. (A) 1967,
423.
(9) (a) Erker, G.; Berg, K.; Benn, R.; Schroth, G. Chem. Ber. 1985,
118, 1383. (b) Erker, G.; Berg, K.; Angerrmund, K.; Kunz, K. Orga-
nometallics 1987, 6, 2620. (c) Hessen, B.; Heijden, H. J . Organomet.
Chem. 1997, 534, 237.

1100 Organometallics, Vol. 22, No. 5, 2003
Ishiyama et al.
Sch em e 8
the formation of Hf-10 via Hf-9, both as a spectroscopi-
cally undetectable intermediate, followed by the ligand
exchange between Hf-10 and Hf-7 to form Hf-8. The
complex Hf-8 slowly decomposed in solution at room
temperature and was isolated as a crude product, which
was characterized narrowly by the 1H and 31P NMR
spectra, but some related complexes could be derived
from Hf-8 (vide infra).
Similar allyl-chloride exchange reactions were con-
ducted in ether or THF in place of toluene, with the view
of stabilizing the chloride phosphide complexes (Zr -8,
Hf-8, Zr -10, and Hf-10) by solvation with ether or THF,
but no practical improvement was attained.
Next, we examined the other synthetic route to Zr -
10 or Hf-10, i.e., the monoallylation reaction of Zr -1 or
Hf-1 with 1 equiv of (allyl)MgCl in ether, which,
however, gave a few kinds of unexpected products. The
31P NMR spectrum of the reaction mixture indicated
that the major product in the Zr case was the diallyl
phosphide complex Zr -7 with a part of the starting
complex Zr -1 left (eq 1). In the Hf case, the major
product was the monoallyl monochloride phosphide
complex Hf-8 (eq 2). These results and those of the
above exchange reactions indicate that the present
phosphide complexes gain some stability when they
have electron-donating allyl group(s) as an ancillary
ligand.
ppm for Hf-12) at the expense of the doublets due to
the starting complex. The spectral change suggests that
the P-H bond has been converted into the M-P
covalent bond. It is probable that this reaction proceeds
via the trityl complex (Zr -11, Hf-11) as an undetectable
intermediate, which affords immediately and quantita-
tively the dichloride phosphide complex (Zr -12, Hf-12)
with liberation of CHPh3, formation of which was
confirmed by the 1H NMR spectrum. The dichloride
complex must be stabilized by solvation with one or
more THF molecules, because the corresponding solva-
tion-free Zr -10 or Hf-10, if formed in Scheme 6, is too
labile to detect. However, the dichloride complex (Zr -
12, Hf-12) solvated by THF could not be isolated owing
to its very high and similar solubility to that of CHPh3.
To convert it into an isolable derivative, moderately
electron-donating N-methylimidazole was added to re-
sult in narrow isolation of the highly air- and moisture-
sensitive dichloride bis(N-methylimidazole) phosphide
complex (Zr -13, 40%; Hf-13, 39%). The product was
identified by the 1H, 13C{1H}, and 31P NMR spectra. The
complexes Zr -13 and Hf-13 together with Zr -7 and Hf-7
provide rare examples of isolable nonmetallocene type
phosphide complexes of group 4 transition metals.3
The similar reaction with 1 equiv of Li(fluorenide) in
place of NaCPh3 and then with N-methylimidazole gave
the same dichloride phosphide complex (Zr -13, Hf-13)
with liberation of fluorene, but it could not be isolated
in a pure form due to the contamination of several
byproducts.
In addition to the above monoallylation which led
eventually to the multiallylation, monobenzylation,
monomethylation, and mono-p-tolylation of Zr -1 or Hf-1
were examined in ether, but the formation of any
phosphide complexes was not discerned in the 31P NMR
spectra. This observation is also in favor of the view that
the allyl group(s) present as an ancillary ligand stabilize
the present phosphide complexes.
Mon otr ityla tion a n d Mon oflu or en yla tion of th e
Secon d a r y P h osp h in e Tr ich lor id e Com p lex. On the
basis of the above monoallylation reaction (eqs 1 and
2), it is necessary to suppress the multisubstitution so
as to obtain the desired dichloride phosphide complex,
though it does not have enough stability as it is. For
this purpose a bulky allyl analogue such as CPh3 and
fluorenyl groups are chosen, because both are expected
not only to control the reaction sterically but also to
coordinate to the metal center with an η3- or η1-mode
to behave like the allyl group in the elimination process.
Furthermore, it is also necessary more or less to
stabilize the unstable dichloride phosphide complex, for
example, by solvation. So, we examined the reaction of
Zr -1 or Hf-1 with 1 equiv of NaCPh3 or Li(fluorenide)
in THF/ether solution (Scheme 8). In the reaction with
NaCPh3, the 31P NMR spectrum without proton irradia-
tion showed a singlet (236.2 ppm for Zr -12 and 176.9
It should be noted here that the direct reaction
dehydrochlorination of Zr -1 or Hf-1 with a base such
as triethylamine, 1,8-diazabicyclo[5,4,0]undec-7-ene (dbu),
N-methylimidazole, etc., did not give the corresponding
dichloride phosphide complex at all, but led to release
of the secondary phosphine moiety from the metal
center.
A single-crystal X-ray structural analysis was per-
formed on Zr -13, the ORTEP drawing of which is shown
in Figure 1. An asymmetric unit contains a pair of the
enantiomers (Zr -13(i), Zr -13(ii)) represented schemati-
cally in Figure 2 and one disordered solvent THF
molecule. The Zr center has a distorted octahedral
coordination geometry which has two chloride groups
in trans positions. The selected bond distances and
angles are summarized in Table 1. The Zr-P distance
(2.600 and 2.597 Å) is smaller than that in the analo-
gous phosphine-pendant Zr complex [{η5-C5H4(CH2)2-

Zirconium and Hafnium Complexes
Organometallics, Vol. 22, No. 5, 2003 1101
Sch em e 9
suggests that the phosphide ligand interacts with the
Zr center more strongly in the present dichloride
complex Zr -13 than in the diamide complex, which is
attributed probably to the higher σ/π-donor ability of
the NEt2 group than that of the chloride group (vide
infra).
The present structural data are comparable also to
those for other monophosphide Zr metallocene com-
plexes reported so far: [Cp2{P(SiMe3)(2,4,6-tBu3C6H2)}-
ZrCl] (Zr-P ) 2.541 Å, sum of bond angles around
P ) 359.5°),2m [Cp2{P(SiMe3)2}ZrCl] (Zr-P ) 2.548 Å,
F igu r e 1. ORTEP drawing of Zr -13. Ellipsoids are shown
at 50% probability level. Hydrogen atoms are omitted for
clarity.
sum of bond angles around
P
) 344.4°),2n and
[Cp2{P(SiMe3)2}ZrMe] (Zr-P ) 2.629 Å, sum of bond
angles around P ) 349.2°).2a,n
The spectroscopic and/or X-ray structural character-
ization of Zr -13 and Hf-13 thus derived support, though
indirectly, that Zr -12 and Hf-12 are the desired dichlo-
ride phosphide complexes which are probably solvated
with two THF molecules, judging from the X-ray struc-
ture of Zr -13. The higher-field 31P NMR resonances in
Zr -13 and Hf-13 (162.8 and 98.4 ppm, respectively) than
in Zr -12 and Hf-12 (236.2 and 176.9 ppm, respectively)
suggest that the P-to-M donation is weaker in the bis-
(N-methylimidazole) complex (Zr -13, Hf-13), consistent
with the usual expectation that the P-to-M donation is
less significant when the ancillary ligands have higher
donor ability like N-methylimidazole, and vice versa.2a
As described above, all of the tribenzyl (Zr -3, Hf-3),
triallyl (Zr -6, Hf-6), and monotrityl/monofluorenyl (Zr -
11, Hf-11) complexes having a PHMes-pendant serve
as an effective precursor of the phosphide-pendant
complexes. A common characteristic of these ligands is
that they are able to coordinate to the metal center with
an η3-mode. Therefore, it is highly probable that the
π-electrons on the R-carbon of these ligands enhance the
electrophilic attack of the P-H moiety to facilitate the
ligand-H coupling, leading to subsequent formation of
the phosphide complex.
F igu r e 2. Enantiomeric isomers of Zr -13.
Ta ble 1. Selected Bon d Dista n ces (Å) a n d Bon d
An gles (d eg) for Zr -13
Zr -13(i)
Zr -13(ii)
Zr1-P1
Zr1-C11
Zr1-C12
Zr1-N1
Zr1-N3
Zr1-C1
Zr1-C2
Zr1-C3
Zr1-C4
Zr1-C5
2.600(2)
2.537(2)
2.563(2)
2.429(5)
2.366(5)
2.589(7)
2.533(6)
2.475(7)
2.483(7)
2.549(7)
Zr2-P2
2.597(2)
2.567(2)
2.537(2)
2.413(6)
2.376(5)
2.589(7)
2.538(7)
2.490(7)
2.498(7)
2.556(7)
Zr2-C13
Zr2-C14
Zr2-N5
Zr2-N7
Zr1-C25
Zr1-C26
Zr1-C27
Zr1-C28
Zr1-C29
Zr1-P1-C7
Zr1-P1-C8
C7-P1-C8
∑ of angles
around P
110.3(3)
119.4(2)
111.9(3)
341.6(8)
Zr2-P2-C31
Zr2-P2-C32
C31-P2-C32
110.4(3)
120.8(2)
111.1(4)
342.3(9)
Der iva tion fr om Mon oa llyl Mon och lor id e P h os-
p h id e Com p lex Hf-8. Of the phosphide complexes
formed in Schemes 6 and 7, the only monoallyl monochlo-
ride complex Hf-8 had a relatively long lifetime, and so
some of its derivatives were prepared as shown in
Scheme 9. Isolable derivatives [{η5-C5H4(CH2)2PMes-
κP}Hf(Y)(allyl)] (Y ) C6F5, Hf-14; Y ) NPh2, Hf-15; Y
) NEt2, Hf-16) were obtained in the reaction of Hf-8
formed in situ (Scheme 7) with 0.5 M Mg(C6F5)2(1,4-
dioxane)x, 1 equiv of KNPh2, and 1 equiv of LiNEt2,
PPh2-κP}ZrCl3(thf)] (2.847 Å),7b showing that the Zr-P
bond in Zr -13 bears a considerable double-bond char-
acter. The phosphorus atom has a distorted trigonal-
planar geometry with the sum of bond angles around it
being 341.7° or 342.4°, indicating that the phosphide
phosphorus has some sp2-hybridization character.2a The
low-field 31P NMR resonance (162.8 ppm, (s), in C6D6)
for Zr -13 also points to the considerable Zr-P π-interac-
tion.2a The structural comparison with the diamide
phosphide-pendant Zr complex [(η5-C5Me4SiMe2PCy-
κP)Zr(NEt2)2] reported recently by Erker et al. (Zr-P
) 2.648 Å, sum of bond angles around P ) 321.2°)3h
1
respectively. They were characterized by H, 13C{1H},
and 31P NMR spectra. The 31P NMR spectra are sum-
marized in Table 2, where the chemical shifts of Hf-7
and Hf-8 are also given for comparison. It can be seen
there that when Y is an electron-withdrawing group

1102 Organometallics, Vol. 22, No. 5, 2003
Ishiyama et al.
Ta ble 2. 31P NMR Sp ectr a of
synthetic method can be applied widely to the prepara-
tion of a variety of high oxidation state transition metal
phosphide complexes.
[η5:η1-{C5H4(CH2)2P Mes}Hf(Y)(a llyl)]
Y
31P NMR (δ, in C6D6)
Hf-14 C6F5
Hf-8 Cl
Hf-7 allyl
Hf-15 NPh2
Hf-16 NEt2
230.1
151.0
118.8
114.9
42.7
Exp er im en ta l Section
All experiments were performed under nitrogen atmosphere
using Schlenk, glovebox, and vacuum line techniques. All
solvents used were dried over Na/K alloy and distilled before
use. Tetrahydrothiophene and N-methylimidazole were dis-
tilled from CaH2. The compounds [η5-{C5H4(CH2)2PHMes-κP}-
MCl3(tht)] (Zr -1, Hf-1),7e MgR2 (R ) Me,10 R ) Et11), Mg(CH2-
Ph)2(thf)2,12 Mg(p-C6H4Me)2(1,4-dioxane)x,13 and NaCPh314 were
prepared by published procedures. The arylation activities of
Mg(p-C6H4Me)2(1,4-dioxane)x and Mg(C6F5)2(1,4-dioxane)x were
determined before use by HCl titration of the solutions treated
individually with H2O and PhCH2Cl. (Allyl)MgCl and LiCH2-
SiMe3 were obtained from common commercial sources and
such as C6F5 and Cl, the 31P NMR signal is observed at
a considerably low magnetic field, while when Y is an
electron-donating group such as NEt2, the signal ap-
pears at a high magnetic field. These 31P NMR data
indicate that the phosphide ligand acts as a stronger
donor when the complex bears weaker donor(s) as
ancillary ligand(s), and vice versa.
If the phosphide phosphorus has a trigonal-planar
geometry, it should be achiral. In contrast, if it does not,
in other words, if it takes a pyramidal geometry, the
phosphorus becomes a chiral center. If so for Hf-8, Hf-
14, Hf-15, and Hf-16 in which the Hf atom is also a
chiral center, these complexes may consist of diastere-
omers giving rise to two sets of resonances in the 31P
NMR spectra. The 31P NMR spectra of these complexes
show one signal, which indicates either a planar geom-
etry of the phosphorus or rapid inversion between
enantiomeric trigonal geometries. The real reason is not
clear at present.
1
used without further purification. H, 13C{1H}, 19F, 29Si, and
31P NMR spectra were recorded on a J EOL LA-300 multi-
nuclear spectrometer. 1H, 13C{1H}, and 29Si NMR data were
referenced to SiMe4, and 19F and 31P NMR data were refer-
enced to CFCl3 and 85% H3PO4, respectively. Elemental
analysis data were obtained on a Perkin-Elmer 2400 CHN
elemental analyzer, but satisfactory results could not be
accessible for some complexes because of their high air- and
moisture-sensitivities and/or intrinsic instabilities.
Syn th esis of Li2C5H4(CH2)2P Mes. The procedure applied
is a modification of that for Li2C5H4(CH)2PPh.7c BuLi (0.31 mL
of BuLi, 1.65 M hexane solution, 0.51 mmol) in 0.31 mL of
hexane was added to LiC5H4(CH2)2P(H)Mes7e (0.51 mmol) in
15 mL of THF at -78 °C. The reaction mixture was warmed
to room temperature and stirred for 10 min. Li2C5H4(CH2)2-
PMes thus formed quantitatively in THF/hexane was used
directly. 31P NMR (121.5 MHz, THF/hexane): δ -92.1 (s).
Syn th esis of [{η5-C5H4(CH2)2P (H)Mes}Zr (CH2SiMe3)3]
(Zr -2). A pentane solution of LiCH2TMS (1.30 mmol) was
added to a suspension of Zr -1 (0.23 g, 0.43 mmol) in 15 mL of
ether at room temperature. The reaction mixture was stirred
overnight and then filtered. The filtrate was reduced in volume
in vacuo to give a brown oil of Zr -2 (0.23 g, 89%). 1H NMR
(300 MHz, C6D6): δ 6.80 (s, 2H, m-H in Mes), 6.06 (m, 2H,
Cp), 6.00 (m, 2H, Cp), 4.37 (dm, J PH ) 214.1 Hz, 1H, PH),
2.60-2.40 (m, 2H, CpCH2), 2.44 (s, 6H, o-Me in Mes), 2.14 (s,
3H, p-Me in Mes), 2.05-1.75 (m, 2H, PCH2), 0.55 (s, 6H, CH2-
SiMe3), 0.16 (s, 27H, SiMe3). 13C{1H} NMR (75.5 MHz, C6D6):
δ 141.8 (d, J PC ) 11.2 Hz, aromatic-C in Mes), 138.0 (s,
aromatic-C in Mes), 131.2 (d, J PC ) 7.4 Hz, aromatic-C in Mes),
130.3 (s, 1-C in Cp), 129.4 (d, J PC ) 2.5 Hz, aromatic-C in Mes),
Catalytic activities in olefin polymerization are now
under investigation for the phosphide complexes iso-
lated in the present study.
Con sid er a tion of th e P en d a n t Effect. Finally, we
examined if the secondary phosphine-pendant ligand is
a requisite in the present synthetic methods we ex-
ploited. Namely, the reaction of readily available CpMCl3-
(tht)2 (Zr -17, Hf-17) with 3 equiv of (allyl)MgCl or 1
equiv of NaCPh3 in the presence of nonpendant PH-
MeMes in ether was conducted. In the reaction with
(allyl)MgCl (cf. Scheme 5), formation of a phosphide
complex such as CpM(allyl)2PMeMes was not detected
at all by the 31P NMR spectrum, but the reaction gave
only CpM(allyl)3 with the added PHMeMes ligand
intact. CpZr(allyl)3 thus formed was so unstable that it
decomposed immediately even at room temperature.9a,b
Likewise, the similar reaction with 1 equiv of NaCPh3
(cf. Scheme 8) did not afford any phosphide complex.
These results suggest that the formation of the present
phosphide complexes requires the secondary phosphine
to be located close to the coordination sphere of the
metal by the pendant effect.
110.1 (s, Cp), 109.2 (s, Cp), 63.3 (s, CH2SiMe3), 29.2 (d, J PC
8.1 Hz, CpCH2), 23.6 (d, J PC ) 15.5 Hz, PCH2), 23.2 (d, J PC
11.2 Hz, o-Me in Mes), 21.0 (s, p-Me in Mes), 2.90 (s, SiMe3).
29Si NMR (59.6 MHz, C6D6): δ -6.95 (s). 31P NMR (121.5 MHz,
C6D6): δ -87.0 (d, J PH ) 218 Hz).
)
)
Syn th esis of [{η5-C5H4(CH2)2P (H)Mes}Hf(CH2SiMe3)3]
(Hf-2). Treatment of Hf-1 (0.25 g, 0.41 mmol) in 15 mL of ether
with LiCH2SiMe3 (1.30 mmol) in a manner similar to that for
Zr -2 resulted in formation of a brown oil of Hf-2 (0.25 g, 89%).
1H NMR (300 MHz, C6D6): δ 6.80 (s, 2H, m-H in Mes), 5.98
(m, 2H, Cp), 5.93 (m, 2H, Cp), 4.37 (dm, J PH ) 214.8 Hz, 1H,
PH), 2.61-2.44 (m, 2H, CpCH2), 2.44 (s, 6H, o-Me in Mes),
2.14 (s, 3H, p-Me in Mes), 2.03-1.74 (m, 2H, PCH2), 0.25 (s,
6H, CH2SiMe3), 0.17 (s, 27H, SiMe3). 13C{1H} NMR (75.5 MHz,
C6D6): δ 141.8 (d, J PC ) 11.2 Hz, aromatic-C in Mes), 138.0
(s, aromatic-C in Mes), 130.4 (d, J PC ) 7.5 Hz, aromatic-C in
Con clu sion s
The tribenzyl, triallyl, monotrityl, and monofluorenyl
complexes of Zr and Hf carrying a secondary phosphine-
pendant are converted into their phosphide-pendant
derivatives with liberation of a ligand-H coupling
product, wherein these alkyl-like ligands coordinated
with an η3- or η1-mode act as an effective leaving group.
In addition, the formation of the present phosphide
complexes requires the secondary phosphine to be
situated close to the metal center by the pendant effect.
The 31P NMR spectra of the phosphide complexes
indicate that the phosphide ligand acts as a better donor
when the complex has poorer donors as ancillary
ligands, and vice versa. It is expected that the present
(10) Ashby, E. C.; Arnott, R. C. J . Organomet. Chem. 1968, 14, 1.
(11) Ashby, E. C.; Becker, W. E. J . Am. Chem. Soc. 1963, 85, 118.
(12) Schrock, R. R. J . Organomet. Chem. 1976, 122, 209.
(13) Dryden, N. H.; Legzdins, P.; Rettig, S. J .; Veltheer, J . E.
Organometallics 1992, 11, 2583.
(14) Renfrow, W. B., J r.; Hauser, C. R. Org. Synth., II 1943, 603.

Zirconium and Hafnium Complexes
Organometallics, Vol. 22, No. 5, 2003 1103
Mes), 129.9 (s, 1-C in Cp), 129.4 (d, J PC ) 3.0 Hz, aromatic-C
in Mes), 110.1 (s, Cp), 109.7 (s, Cp), 69.7 (s, CH2SiMe3), 29.2
(d, J PC ) 8.1 Hz, CpCH2), 23.8 (d, J PC ) 15.5 Hz, PCH2), 23.2
(d, J PC ) 11.2 Hz, o-Me in Mes), 21.0 (s, p-Me in Mes), 3.2 (s,
SiMe3). 29Si NMR (59.6 MHz, C6D6): δ -5.15 (s). 31P NMR
(121.5 MHz, C6D6): δ -87.1 (d, J PH ) 216 Hz). Anal. Calcd
for C28H53HfPSi3: C, 49.21; H, 7.82. Found: C, 49.06; H, 7.89.
Syn th esis of [{η5-C5H4(CH2)2P (H)Mes}Zr (CH2P h )3] (Zr -
3). A solution of Mg(CH2Ph)2(thf)2 (1.09 g, 3.11 mmol) in 10
mL of ether was added slowly to a suspension of Zr -1 (1.10 g,
2.07 mmol) in 70 mL of ether at room temperature. The
reaction mixture was stirred for 1 h and then filtered. The
filtrate was reduced in volume in vacuo to give a brown oil of
Zr -3 (1.11 g, 88%). 1H NMR (300 MHz, C6D6): δ 7.29-7.04
(m, 9H, Ph), 6.91 (s, 2H, m-H in Mes), 6.59 (m, 6H, Ph), 5.63
(m, 2H, Cp), 5.50 (m, 2H, Cp), 4.45 (dm, J PH ) 214.8 Hz, 1H,
PH), 2.54 (s, 6H, o-Me in Mes), 2.52-2.44 (m, 2H, CpCH2),
2.22 (s, 3H, p-Me in Mes), 2.00-1.83 (m, 2H, PCH2), 1.63 (s,
6H, CH2Ph). 13C{1H} NMR (75.5 MHz, C6D6): δ 143.7 (s, Ph),
141.9 (d, J PC ) 11.8 Hz, aromatic-C in Mes), 138.1 (s,
aromatic-C in Mes), 130.0 (d, J PC ) 6.9 Hz, aromatic-C Mes),
130.0 (s, Ph), 129.4 (s, 1-C in Cp), 129.3 (s, aromatic-C Mes),
127.6 (s, Ph), 123.5 (s, Ph), 111.6 (s, 2,5- or 3,4-C in Cp), 111.5
(s, 2,5- or 3,4-C in Cp), 66.2 (s, CH2Ph), 29.0 (d, J PC ) 8.8 Hz,
CpCH2), 23.3 (d, J PC ) 16.1 Hz, PCH2), 23.2 (d, J PC ) 11.8 Hz,
o-Me in Mes), 21.0 (s, p-Me in Mes). 31P NMR (121.5 MHz,
C6D6): δ -86.9 (d, J PH ) 215 Hz). Anal. Calcd for C37H41PZr:
C, 73.10; H, 6.80. Found: C, 72.84; H, 6.62.
was sealed into an NMR glass tube. The tube was kept at 80
°C, and the thermolysis resulted in quantitative formation of
Zr -5, which was monitored by the NMR measurements. Zr -5
decomposed slowly in solution, which interfered with the 13C-
{1H} NMR measurement. 1H NMR (300 MHz, C6D6): δ 7.20-
6.52 (m, 10H, Ph), 6.93 (s, 2H, m-H in Mes), 5.65 (m, 2H, Cp),
5.55 (m, 2H, Cp), 2.91-2.45 (m, 4H, CH2CH2), 2.48 (s, 6H, o-Me
in Mes), 2.23 (s, 4H, CH2Ph), 2.15 (s, 3H, p-Me in Mes). 31P
NMR (121.5 MHz, C6D6): δ 126.0 (s).
Syn th esis of [{η5-C5H4(CH2)2P Mes-KP}Hf(CH2P h )2] (Hf-
5). A solution of Hf-3 (0.030 g, 0.043 mmol) in 0.4 mL of C6D6
was kept at 80 °C in a manner similar to that for Zr -5. The
thermolysis for 4 h resulted in quantitative formation of Hf-
5. Hf-5 decomposed slowly in solution, which interfered with
the 13C{1H} NMR measurement. 1H NMR (300 MHz, C6D6):
δ 7.28-6.82 (m, 10H, Ph), 7.05 (s, 2H, m-H in Mes), 5.77 (m,
2H, Cp), 5.58 (m, 2H, Cp), 3.16-2.35 (m, 4H, CH2CH2), 2.64
(s, 6H, o-Me in Mes), 2.35 (s, 4H, CH2Ph), 2.22 (s, 3H, p-Me in
Mes). 31P NMR (121.5 MHz, C6D6): δ 111.2 (s).
Syn th esis of [{η5-C5H4(CH2)2P Mes-KP}Zr (a llyl)2] (Zr -7).
A solution of (allyl)MgCl (26.90 mmol) in 12 mL of THF was
added to a suspension of Zr -1 (4.74 g, 8.97 mmol) in 80 mL of
ether at room temperature. After stirring overnight, the
volatiles were evaporated in vacuo. The orange residue ob-
tained was extracted with ether/hexane (2:1) and then filtered.
Removal of the solvents gave a brown powder of Zr -7 (2.95 g,
1
79%). H NMR (300 MHz, C6D6): δ 6.92 (s, 2H, m-H in Mes),
5.37-5.29 (m, 6H, Cp and 2-H in allyl), 2.90 (m, 2H, CpCH2),
2.85 (d, J HH ) 12.6 Hz, 4H, 1,3-H in allyl), 2.84 (d, J HH ) 12.3
Hz, 4H, 1,3-H in allyl), 2.63 (s, 6H, o-Me in Mes), 2.62 (m, 2H,
PCH2), 2.19 (s, 3H, p-Me in Mes). 13C{1H} NMR (75.5 MHz,
C6D6): δ 142.4 (d, J PC ) 4.3 Hz, aromatic-C in Mes), 137.6 (s,
aromatic-C in Mes), 131.2 (s, aromatic-C in Mes), 130.9 (d, J PC
) 3.8 Hz, 2-C in allyl), 129.4 (s, 1-C in Cp), 128.8 (d, J PC ) 5.0
Hz, aromatic-C in Mes), 103.8 (s, 2,5- or 3,4-C in Cp), 101.9
(s, 2,5- or 3,4-C in Cp), 64.4 (s, 1,3-C in allyl), 37.3 (s, CpCH2),
27.5 (d, J PC ) 16.1 Hz, PCH2), 23.7 (d, J PC ) 8.7 Hz, o-Me in
Mes), 21.1 (s, p-Me in Mes). 31P NMR (121.5 MHz, C6D6): δ
147.4 (s). Anal. Calcd for C22H29PZr: C, 63.57; H, 7.03.
Found: C, 63.51; H, 6.97.
Syn th esis of [{η5-C5H4(CH2)2P Mes-KP}Hf(a llyl)2] (Hf-7).
Treatment of Hf-1 (5.95 g, 9.65 mmol) in 100 mL of ether with
(allyl)MgCl (28.95 mmol) in a manner similar to that for Zr -7
resulted in formation of a brown powder of Hf-7 (4.34 g, 89%).
1H NMR (300 MHz, C6D6): δ 6.92 (s, 2H, m-H in Mes), 5.47-
5.35 (m, 2H, 2-H in allyl), 5.42 (m, 2H, Cp), 5.35 (m, 2H, Cp),
2.96 (m, 2H, CpCH2), 2.76 (d, J HH ) 12.5 Hz, 4H, 1,3-H in
allyl), 2.76 (m, 2H, PCH2), 2.75 (d, J HH ) 12.3 Hz, 4H, 1,3-H
in allyl), 2.62 (s, 6H, o-Me in Mes), 2.20 (s, 3H, p-Me in Mes).
13C{1H} NMR (75.5 MHz, C6D6): δ 142.9 (d, J PC ) 4.9 Hz,
aromatic-C in Mes), 137.5 (s, aromatic-C in Mes), 132.1 (d, J PC
) 3.1 Hz, 2-C in allyl), 130.9 (s, 1-C in Cp), 130.4 (s, aromatic-C
in Mes), 128.8 (d, J PC ) 5.6 Hz, aromatic-C in Mes), 103.9 (s,
2,5- or 3,4-C in Cp), 101.9 (s, 2,5- or 3,4-C in Cp), 64.3 (s, 1,3-C
in allyl), 36.5 (s, CpCH2), 27.1 (d, J PC ) 16.1 Hz, PCH2), 23.9
(d, J PC ) 8.7 Hz, o-Me in Mes), 21.0 (s, p-Me in Mes). 31P NMR
(121.5 MHz, C6D6): δ 118.8 (s). Anal. Calcd for C22H29HfP: C,
52.54; H, 5.81. Found: C, 52.18; H, 6.33.
Syn th esis of [{η5-C5H4(CH2)2P Mes-KP}HfCl(a llyl)] (Hf-
8). The mixture of Hf-1 (0.061 g 0.10 mmol) and Hf-7 (0.10 g,
0.20 mmol) was dissolved in 10 mL of toluene with stirring at
room temperature. After 30 min, Hf-8 was quantitatively
formed. The compound decomposed slowly in solution, so that
it was isolated as a crude brown product with difficulty. 1H
NMR (300 MHz, C6D6): δ 6.93 (s, 2H, m-H in Mes), 6.27 (m,
1H, Cp), 6.13 (m, 1H, Cp), 5.95 (m, 1H, Cp), 5.35-5.18 (m,
1H, 2-H in allyl), 4.75 (m, 1H, Cp), 3.33-2.40 (m, 8H, CH2-
CH2 and 1,3-H in allyl), 2.57 (s, 6H, o-Me in Mes), 2.21 (s, 3H,
p-Me in Mes). 31P NMR (121.5 MHz, C6D6): δ 151.0 (s).
Syn th esis of [{η5-C5H4(CH2)2P Mes-KP}Zr Cl2(N-m eth -
ylim id a zole)2] (Zr -13). A solution of NaCPh3, generated in
Syn th esis of [{η5-C5H4(CH2)2P (H)Mes}Hf(CH2P h )3] (Hf-
3). Treatment of Hf-1 (1.54 g, 2.50 mmol) in 70 mL of ether
with Mg(CH2Ph)2(thf)2 (1.32 g, 3.76 mmol) in 10 mL of ether
in a manner similar to that for Zr -3 resulted in formation of
1
a brown oil of Hf-3 (1.59 g, 91%). H NMR (300 MHz, C6D6):
δ 7.29-7.02 (m, 9H, Ph), 6.91 (s, 2H, m-H in Mes), 6.76 (m,
6H, Ph), 5.59 (m, 2H, Cp), 5.53 (m, 2H, Cp), 4.39 (dm, J PH
)
215.0 Hz, 1H, PH), 2.52 (s, 6H, o-Me in Mes), 2.52-2.40 (m,
2H, CpCH2), 2.22 (s, 3H, p-Me in Mes), 1.93-1.89 (m, 2H,
PCH2), 1.72 (s, 6H, CH2Ph). 13C{1H} NMR (75.5 MHz, C6D6):
δ 144.3 (s, Ph), 141.8 (d, J PC ) 11.8 Hz, aromatic-C in Mes),
138.1 (s, aromatic-C in Mes), 131.3 (d, J PC ) 8.1 Hz, aromatic-C
in Mes), 130.0 (s, 1-C in Cp), 129.4 (d, J PC ) 3.2 Hz, aromatic-C
in Mes), 129.2 (s, Ph), 127.7 (s, Ph), 123.2 (s, Ph), 112.7 (s,
Cp), 112.0 (s, Cp), 78.0 (s, CH2Ph), 28.5 (d, J PC ) 8.7 Hz,
CpCH2), 23.2 (d, J PC ) 11.8 Hz, o-Me in Mes), 23.2 (d, J PC
)
14.9 Hz, PCH2), 21.0 (s, p-Me in Mes). 31P NMR (121.5 MHz,
C6D6): δ -86.8 (d, J PH ) 215 Hz). Anal. Calcd for C37H41HfP:
C, 63.92; H, 5.94. Found: C, 64.21; H, 5.70.
Syn th esis of [{η5-C5H4(CH2)2P (H)Mes}Hf(p-tolyl)3] (Hf-
4). A suspension of Mg(p-C6H4Me)2(1,4-dioxane)x (1.48 mmol)
in 10 mL of ether was added to a suspension of Hf-1 (0.61 g,
0.99 mmol) in 30 mL of ether at room temperature. The
reaction mixture was stirred overnight and then filtered. The
filtrate was reduced in volume in vacuo to give a yellow powder
of Hf-4 (0.56 g, 82%). 1H NMR (300 MHz, C6D6): δ 7.76 (d,
J HH ) 7.5 Hz, 6H, tolyl), 7.13 (d, J HH ) 7.5 Hz, 6H, tolyl), 6.70
(s, 2H, m-H in Mes), 6.34 (m, 1H, Cp), 6.29 (m, 1H, Cp), 6.18
(m, 2H, Cp), 4.27 (dm, J PH ) 245.3 Hz, 1H, PH), 2.58-2.33
(m, 2H, CpCH2), 2.18 (s, 15H, p-Me in tolyl and o-Me in Mes),
2.10 (s, 3H, p-Me in Mes), 1.93-1.89 (m, 2H, PCH2). 13C{1H}
NMR (75.5 MHz, C6D6): δ 200.3 (d, J PC ) 1.9 Hz, aromatic-C
in tolyl), 141.8 (d, J PC ) 10.6 Hz, aromatic-C in Mes), 138.1
(s, aromatic-C in Mes), 137.6 (s, aromatic-C in tolyl), 136.3 (s,
aromatic-C in tolyl), 132.6 (s, 1-C in Cp), 129.3 (s, aromatic-C
in Mes), 128.3 (s, aromatic-C in tolyl), 127.2 (s, aromatic-C in
Mes), 113.6 (s, Cp), 113.1 (s, Cp), 112.3 (s, Cp), 111.2 (s, Cp),
28.3 (d, J PC ) 8.7 Hz, CpCH2), 24.1 (d, J PC ) 6.0 Hz, o-Me in
Mes), 22.8 (d, J PC ) 9.3 Hz, PCH2), 21.6 (s, p-Me in tolyl), 20.9
(s, p-Me in Mes). 31P NMR (121.5 MHz, C6D6): δ -66.2 (br d,
J PH ) 243 Hz).
Syn th esis of [{η5-C5H4(CH2)2P Mes-KP}Zr (CH2P h )2] (Zr -
5). A solution of Zr -3 (0.025 g, 0.041 mmol) in 0.4 mL of C6D6

1104 Organometallics, Vol. 22, No. 5, 2003
Ishiyama et al.
situ (0.35 mmol) in 20 mL of ether, was slowly added to a
solution of Zr -1 (0.19 g, 0.35 mmol) in 25 mL of THF at room
temperature. The reaction mixture was stirred for 30 min, and
then the solvents were removed in vacuo. The residue was
dissolved in 20 mL of toluene, and the solution was filtered.
To the filtrate was slowly added a solution of N-methylimi-
dazole (0.039 g, 0.47 mmol) in 10 mL of THF (addition of 2
equiv or more of N-methylimidazole gave rise to decomposition
of the product). After stirring for 10 min, the solution was
reduced in volume in vacuo, and then the residue was washed
with ether, followed by drying it in vacuo to yield a red powder
of Zr -13 (40% based on Zr -1, 0.080 g). 1H NMR (300 MHz,
C6D6): δ 8.33 (s, 1H, imidazole), 8.23 (s, 1H, imidazole), 8.10
(s, 1H, imidazole), 8.00 (s, 1H, imidazole), 6.74 (s, 2H, m-H in
Mes or Cp), 6.67 (s, 2H, m-H in Mes or Cp), 6.17 (s, 2H, Cp),
5.84 (s, 1H, imidazole), 5.69 (s, 1H, imidazole), 3.41 (m, 2H,
CpCH2), 3.21-3.08 (m, 2H, PCH2), 2.70 (s, 6H, o-Me in Mes),
2.15 (s, 6H, MeN), 2.08 (s, 3H, p-Me in Mes). 13C{1H} NMR
(75.5 MHz, C6D6): δ 144.0 (s, imidazole), 143.3 (s, imidazole),
143.2 (s, imidazole), 141.3 (s, imidazole), 139.9 (d, J PC ) 3.7
dissolved in 5 mL of THF at room temperature. The reaction
mixture was stirred for 1 h, and then the solvents were
removed in vacuo. The residue was extracted with toluene, and
the extract was filtered. The filtrate was concentrated in vacuo
1
to give a brown powder of Hf-14 (0.16 g, 85%). H NMR (300
MHz, C6D6): δ 6.86 (s, 2H, m-H in Mes), 6.07 (m, 1H, Cp),
6.02 (m, 1H, Cp), 5.64-5.48 (m, 1H, 2-H in allyl), 5.53 (m, 1H,
Cp), 5.37 (m, 1H, Cp), 3.35-2.00 (m, 14H, CH2CH2, 1,3-H in
allyl, and o-Me in Mes), 2.15 (s, 3H, p-Me in Mes). 19F NMR
(282.7 MHz, C6D6): δ -115.0 (m, 2F), -157.0 (m, 1F), -162.1
(m, 2F). 31P NMR (121.5 MHz, C6D6): δ 230.1 (m). Anal. Calcd
for C25H24F5HfP: C, 47.74; H, 3.85. Found: C, 47.45; H, 3.89.
Syn th esis of [{η5-C5H4(CH2)2P Mes-KP}Hf(NP h 2)(a llyl)]
(Hf-15). The synthetic procedure was similar to that for Hf-
14, using Hf-1 (0.061 g, 0.10 mmol), Hf-7 (0.10 g, 0.20 mmol),
and KNPh2 (0.30 mmol) prepared by the reaction of NHPh2
(0.051 g, 0.30 mmol) with KH (0.012 g, 0.30 mmol) in 10 mL
of THF. A brown powder of Hf-15 was obtained (0.17 g, 89%).
1H NMR (300 MHz, C6D6): δ 7.36-6.71 (m, 12H, Ph and m-H
in Mes), 5.93 (m, 1H, Cp), 5.48 (m, 1H, Cp), 5.40-5.32 (m, 2H,
Cp and 2-H in allyl), 5.14 (m, 1H, Cp), 3.33-2.65 (m, 8H, CH2-
CH2, 1,3-H in allyl), 2.40 (s, 6H, o-Me in Mes) 2.19 (s, 3H, p-Me
in Mes). 31P NMR (121.5 MHz, C6D6): δ 114.9 (s). Anal. Calcd
for C31H34HfNP: C, 59.09; H, 5.44; N, 2.22. Found: C, 59.42;
H, 5.27; N, 2.06.
Syn th esis of [{η5-C5H4(CH2)2P Mes-KP}Hf(NEt2)(a llyl)]
(Hf-16). The synthetic procedure was similar to that for Hf-
14, using Hf-1 (0.061 g, 0.10 mmol), Hf-7 (0.10 g, 0.20 mmol),
and LiNEt2(0.30 mmol) prepared by the reaction of NHEt2
(0.022 g, 0.30 mmol) with BuLi (0.18 mL of BuLi, 1.65 M
hexane solution, 0.30 mmol) in 10 mL of THF. A brown powder
of Hf-16 was obtained (0.13 g, 82%). 1H NMR (300 MHz,
C6D6): δ 7.02 (s, 2H, m-H in Mes), 6.18 (m, 1H, Cp), 5.85 (m,
1H, Cp), 5.32 (m, 1H, Cp), 4.84 (m, 2H, Cp and 2-H in allyl),
3.44-2.64 (m, 12H, CH2CH2, 1,3-H in allyl, and NCH2), 2.54
Hz, aromatic-C in Mes), 138.1 (s, 1-C in Cp), 136.0 (d, J PC
)
1.9 Hz, aromatic-C in Mes), 131.5 (br s, aromatic-C in Mes),
129.9 (s, aromatic-C in Mes), 119.0 (s, imidazole or 2,5- or 3,4-C
in Cp), 117.4 (s, imidazole or 2,5- or 3,4-C in Cp), 116.0 (s,
imidazole or 2,5- or 3,4-C in Cp), 112.1 (s, imidazole or 2,5- or
3,4-C in Cp), 37.5 (s, CpCH2), 32.5 (s, MeN), 32.4 (s, MeN),
27.7 (d, J PC ) 19.8 Hz, PCH2), 24.0 (d, J PC ) 9.9 Hz, o-Me in
Mes), 20.9 (s, p-Me in Mes). 31P NMR (121.5 MHz, C6D6): δ
162.8 (s).
Syn th esis of [{η5-C5H4(CH2)2P Mes-KP}HfCl2(N-m eth -
ylim id a zole)2] (Hf-13). Treatment of Hf-1 (0.17 g, 0.28 mmol)
in 25 mL of THF with NaCPh3 (0.28 mmol) in 20 mL of ether
and then with N-methylimidazole (0.032 g, 0.39 mmol) in 10
mL of THF in a manner similar to that for Zr -13 resulted in
formation of an orange powder of Hf-13 (39% based on Hf-1,
0.071 g). 1H NMR (300 MHz, C6D6): δ 8.20 (s, 2H, imidazole),
7.94 (s, 2H, imidazole), 6.71 (s, 4H, m-H in Mes & Cp), 6.02
(s, 2H, Cp), 5.81 (s, 1H, imidazole), 5.69 (s, 1H, imidazole),
3.66 (m, 2H, CpCH2), 3.31-3.19 (m, 2H, PCH2), 2.74 (s, 6H,
o-Me in Mes), 2.17 (s, 3H, p-Me in Mes), 2.14 (s, 6H, MeN).
13C{1H} NMR (75.5 MHz, C6D6): δ 144.6 (s, imidazole), 143.7
(s, imidazole), 143.6 (s, imidazole), 141.5 (s, imidazole), 141.4
(d, J PC ) 5.1 Hz, aromatic-C in Mes), 136.8 (s, 1-C in Cp), 134.9
(d, J PC ) 1.9 Hz, aromatic-C in Mes), 131.4 (br-s, aromatic-C
in Mes), 129.3 (s, aromatic-C in Mes), 119.3 (s, imidazole or
2,5- or 3,4-C in Cp), 117.3 (s, imidazole or 2,5- or 3,4-C in Cp),
116.4 (s, imidazole or 2,5- or 3,4-C in Cp), 111.1 (s, imidazole
or 2,5- or 3,4-C in Cp), 36.0 (s, CpCH2), 32.6 (s, MeN), 32.5 (s,
MeN), 27.2 (d, J PC ) 22.9 Hz, PCH2), 24.5 (d, J PC ) 11.8 Hz,
o-Me in Mes), 20.8 (s, p-Me in Mes). 31P NMR (121.5 MHz,
C6D6): δ 98.4 (s).
Syn th esis of Mg(C6F 5)2(1,4-d ioxa n e)x. The procedure
applied is a modification of that for Mg(p-C6H4Me)2(1,4-
dioxane)x.13 To a 500 mL ether solution of (C6F5)MgBr15 (0.056
mol) was added slowly 1,4-dioxane (4.77 mL, 0.056 mol). The
white slurry formed was stirred overnight and then centri-
fuged. The supernatant was filtered and concentrated to ca.
250 mL in vacuo. To the solution was added slowly 1,4-dioxane
again (4.77 mL, 0.056 mol) to give a white suspension. After
stirring for 4 h, the solvent was removed in vacuo. A white
residue obtained was washed with hexane, followed by drying
it in vacuo to yield a white powder of Mg(C6F5)2(1,4-dioxane)x
(6.39 g).
(s, 6H, o-Me in Mes) 2.28 (s, 3H, p-Me in Mes), 0.86 (t, J HH
)
7.0 Hz, 6H, CH2CH3). 31P NMR (121.5 MHz, C6D6): δ 42.7 (d,
J PH ) 40 Hz).
Syn t h esis of [η5-Cp Zr Cl3(t h t )2] (Zr -17). Tetrahydro-
thiophene (0.15 g, 1.68 mmol) was added slowly to a suspen-
sion of [η5-CpZrCl3]16 (0.22 g, 0.84 mmol) in 15 mL of toluene
at room temperature. The colorless solution formed was stirred
for 30 min, and then the solvent was removed in vacuo. The
white residue obtained was washed with hexane, followed by
drying it in vacuo to give a white powder of Zr -17 (0.34 g, 92%).
1H NMR (300 MHz, C6D6): δ 6.36 (s, 5H, Cp), 3.44 (br-s, 8H,
tht), 1.44 (m, 8H, tht). 13C{1H} NMR (75.5 MHz, C6D6): δ 120.4
(s, Cp), 37.1 (br s, tht), 30.0 (s, tht). Anal. Calcd for C13H21
-
Cl3S2Zr: C, 35.57; H, 4.82. Found: C, 36.08; H, 4.24.
Syn th esis of [η5-Cp HfCl3(th t)2] (Hf-17). The procedure
applied is a modification of that for [CpHfCl3(SMe2)2].17 Tet-
rahydrothiophene (2.48 g, 28.20 mmol) was added to a suspen-
sion of HfCl4 (4.51 g, 14.10 mmol) in 70 mL of toluene at room
temperature, and then the reaction mixture was treated with
CpSnnBu3 (5.01 g, 14.10 mmol) in 10 mL of toluene. After
stirring overnight at 70 °C to complete the reaction, the solvent
was removed in vacuo. The white residue obtained was washed
with hexane/toluene (1:2) and dried in vacuo to give a white
1
powder of Hf-17 (4.53 g, 61%). H NMR (300 MHz, C6D6): δ
6.16 (s, 5H, Cp), 3.13 (br s, 8H, tht), 1.38 (m, 8H, tht). 13C{1H}
NMR (75.5 MHz, C6D6): δ 117.8 (s, Cp), 37.4 (br s, tht), 30.0
(s, tht). Anal. Calcd for C13H21Cl3HfS2: C, 29.67; H, 4.02.
Found: C, 29.98; H, 3.74.
Syn th esis of [{η5-C5H4(CH2)2P Mes-KP}Hf(C6F 5)(a llyl)]
(Hf-14). A mixture of Hf-1 (0.061 g, 0.10 mmol) and Hf-7 (0.10
g, 0.20 mmol) was dissolved in 10 mL of toluene with stirring.
After 30 min, to the toluene solution containing Hf-8 formed
in situ was added slowly Mg(C6F5)2(1,4-dioxane)x (0.30 mmol)
Syn th esis of P HMeMes. MeI (7.14 g, 50.30 mmol) in 60
mL of THF was added slowly to LiPHMes (50.30 mmol)
prepared from PH2Mes18 (7.55 g, 50.30 mmol) and BuLi (30.48
(16) Erker, G.; Berg, K.; Treschanke L.; Engel, K. Inorg. Chem. 1982,
21, 1277.
(17) Lund, E. C.; Livinghouse, T. Organometallics 1990, 9, 2426.
(18) J empty, T. C.; Gogins, K. A. Z.; Mazur, Y.; Miller, L. L. J . Org.
Chem. 1981, 46, 4545.
(15) Barlow, M. G.; Green, M.; Haszeldine, R. N.; Higson, H. G. J .
Chem. Soc. (C) 1966, 1592.

Zirconium and Hafnium Complexes
Organometallics, Vol. 22, No. 5, 2003 1105
Ta ble 3. Cr ysta l Da ta for (Zr -13)‚(th f)0.5
mL of BuLi, 1.65 M hexane solution, 50.30 mmol) in 200 mL
of THF at -78 °C. The reaction mixture was warmed to room
temperature and stirred for 1 h. The solvent was removed in
vacuo, and then 100 mL of ether and 50 mL of degassed water
were added to the white residue. After LiI was extracted with
degassed water, the ether layer was separated and dried over
MgSO4. The solution was filtered, and then the filtrate was
reduced in volume in vacuo. The residue was distilled under
reduced pressure to give a colorless liquid of PHMeMes (5.18
empirical formula
fw
C26H35Cl2N4O0.5PZr
604.69
cryst dimens
cryst syst
0.50 × 0.40 × 0.05 mm
triclinic
lattice params
a ) 8.0490(2) Å
b ) 16.4160(3) Å
c ) 21.9390(6) Å
R ) 81.054(1)°
â ) 88.255(1)°
γ ) 89.857(1)°
V ) 2862.3(1) Å3
P1h (#2)
1
g, 62%, bp 85 °C/1.5 Torr). H NMR (300 MHz, C6D6): δ 6.79
(s, 2H, m-H in Mes), 4.32 (dm, J PH ) 213.3 Hz, 1H, PH), 2.43
(s, 6H, o-Me in Mes), 2.13 (s, 3H, p-Me in Mes) 1.05 (m, 3H,
PMe). 13C{1H} NMR (75.5 MHz, C6D6): δ 141.6 (d, J PC ) 12.4
Hz, aromatic-C in Mes), 137.8 (s, aromatic-C in Mes), 130.1
(d, J PC ) 3.0 Hz, aromatic-C in Mes), 129.3 (d, J PC ) 3.7 Hz,
aromatic-C in Mes), 22.8 (d, J PC ) 11.8 Hz, o-Me in Mes), 21.0
(s, p-Me in Mes), 4.7 (d, J PC ) 14.3 Hz, PMe). 31P NMR (121.5
MHz, C6D6): δ -105.6 (d, J PH ) 214 Hz).
X-r a y Cr ysta llogr a p h y. The red single crystals of Zr -13
were obtained from its THF/hexane solution. The single crystal
covered with an inert oil was mounted on a glass fiber and
cooled to 200 K with a cold nitrogen gas flow. The measure-
ment was made on a Mac Science DIP2030 imaging plate area
diffractometer with graphite-monochromated Mo KR radiation
(λ ) 0.71069 Å). Indexing was performed from 180 oscillations
which were exposed for 3.3 min. The crystal-to-detector
distance was 100.00 mm with the detector at the zero swing
position. Readout was performed in the 0.10 mm pixel mode.
The data were collected up to a maximum 2θ value of 56°. Cell
parameters and reflection intensities were estimated using the
program package MacDENZO.19 The structure was solved by
direct methods with the SIR-92 program system20 and ex-
panded using Fourier techniques. Non-hydrogen atoms were
space group
Z value
Dcalc
no. of reflns measd
no. of obsd reflns
(I>2.00σ(I), 2θ < 50.00°)
no. of variables
residuals: R; Rw
GOF
4
1.403 g/cm3
12 393
7776
622
0.071; 0.115
1.37
refined anisotropically. Hydrogen atoms were fixed at calcu-
lated positions and included at the final stage of refinements
with fixed parameters. All calculations were carried out using
the teXsan crystallographic software package from the Mo-
lecular Structure Corp.21 The crystallographic data for Zr -13
are summarized in Table 3.
Ack n ow led gm en t. We acknowledge financial sup-
port (14654123 and 14044071) from Ministry of Educa-
tion, Science, Sports, and Culture, J apan.
Su p p or tin g In for m a tion Ava ila ble: Tables giving posi-
tional and thermal parameters, crystallographic data, and
bond lengths and angles for Zr -13. This material is available
free of charge via the Internet at http://pubs.acs.org.
(19) MacDENZO: Gewirth, D. (with the cooperation of the program
authors Otwinowski, Z., and Minor, W.) In The MacDenzo Manual-A
Description of the Programs DENZO, XDISPLAYF, and SCALEPACK;
Yale University: New Haven, CT, 1995.
OM020916+
(20) SIR-92: Altomare, A.; Cascarano, G.; Giacovazzo, C.; Gur-
gliardi, A.; Burla, M. C.; Polidori, G.; Camalli, M.; University of Bari:
Bari, Italy, 1992.
(21) teXsan: Single-Crystal Structure Analysis Software, Version
1.6; Molecular Structure Corp.: The Woodlands, TX, 1993.