(2-Diphenylphosphinoethyl)cyclopentadienyl complexes of zirconium (IV): Synthesis, crystal structure and dynamic behaviour in solutions

Article abstract of DOI:10.1016/S0277-5387(98)00167-3

The novel [η⁵:η ¹-(2-diphenylphosphinoethyl)cyclopentadienyl]trichlorozirconium (IV) 3 has been prepared via (2-diphenylphosphinoethyl)(trimethylsilyl)cyclopentadiene 2. The structures of an adduct of 3 with tetrahydrofuran (THF) 3b (two crystal modifications) and of an ionic complex derived from 3 and ZrCl₄ {[η⁵:η¹-(C₅H₄CH ₂CH₂PPh₂)ZrCl]₂(μ-Cl) ₃}⁺₂[(ZrCl₄) ₂(μ-Cl)₂]²- 4 have been determined by an X-ray analysis. The X-ray and NMR data prove the existence of a Zr-P intramolecular coordination in 3 both in solid state and in non-solvating media within a broad range of temperatures. In THF solution the flexible equilibrium between adducts of 3 with one (3b) and two (3c) molecules of THF has been observed by variable-temperature NMR spectroscopy. The synthetic route to the simplest unsymmetrically ligated zirconocene (η⁵-C₅H₄CH₂ CH₂PPh₂)(η⁵-C₅H ₅)ZrCl₂ 5 derived from 3 has also been elaborated.

Full text of DOI:10.1016/S0277-5387(98)00167-3

Polyhedron Vol[ 06\ No[ 11\ pp[ 2778Ð2890\ 0887
Þ 0887 Elsevier Science Ltd
Pergamon
All rights reserved[ Printed in Great Britain
9166Ð4276:87 ,08[99¦9[99
\
PII] S9166Ð4276"87#99056Ð2
"1!Diphenylphosphinoethyl#cyclopentadienyl
complexes of zirconium "IV#] synthesis\ crystal
structure and dynamic behaviour in solutions
Dmitrii P[ Krut|ko\ꢀa Maxim V[ Borzov\a Eduard N[ Veksler\a
Andrei V[ Churakovbc and Judith A[ K[ Howard$c
aDepartment of Chemistry\ Moscow State University\ Leninskie Gory\ Moscow\ 008788\ Russia
bN[S[ Kurnakov Institute of General and Inorganic Chemistry\ Russian Academy of Science\ Leninskii
prospect 20\ Moscow\ 006896\ Russia
cDepartment of Chemistry\ University of Durham\ Science Laboratories\ South Road\ Durham\ DH0
2LE\ United Kingdom
"Received 6 January 0887^ accepted 7 April 0887#
Abstract*The novel ðh4]h0!"1!diphenylphosphinoethyl#cyclopentadienylŁtrichlorozirconium "IV# 2 has been
prepared via "1!diphenylphosphinoethyl#"trimethylsilyl#cyclopentadiene 1[ The structures of an adduct of 2
with tetrahydrofuran "THF# 2b "two crystal modi_cations# and of an ionic complex derived from 2 and ZrCl3
"ðh4]h0−"C4H3CH1CH1PPh1#ZrClŁ1"m−Cl#2#¦1ð"ZrCl3#1"m−Cl#1Ł1− 3 have been determined by an X!ray analy!
sis[ The X!ray and NMR data prove the existence of a ZrÐP intramolecular coordination in 2 both in solid
state and in non!solvating media within a broad range of temperatures[ In THF solution the ~exible equilibrium
between adducts of 2 with one "2b# and two "2c# molecules of THF has been observed by variable!temperature
NMR spectroscopy[ The synthetic route to the simplest unsymmetrically ligated zirconocene "h4!C4H3CH1
CH1PPh1#"h4!C4H4#ZrCl1 4 derived from 2 has also been elaborated[ Þ 0887 Elsevier Science Ltd[ All rights
reserved
Keywords] zirconium^ substituted cyclopentadienes^ crystal structure^ NMR spectroscopy[
———————————————————————————————————————————————
Transition metal complexes with v!hetero! pounds of the general type LnM"C4H3CH1CH1PR1#
atomsubstituted alkylcyclopentadienyl type ligands with M Ga and In ð6Ł\ Fe ð7Ł\ Co ð3Ł\ and Rh and Ir
1
are now under intensive investigation ð0Ł[ However\ ð8Ł have been described[ In connection with this we
only few examples of diorganophosphino!group side considered it attractive to prepare and study the struc!
chain functionalized cyclopentadienyl derivatives of ture
of
ðh4]h0!"1!diphenylphosphinoethyl#cyclo!
the Group 3 metals are known ð1Ð5Ł\ with the only pentadienylŁtrichlorozirconium "IV# 2[ Complex 2 was
representative of monocyclopentadienyl complexes\ initially supposed to exhibit dynamic behaviour in
ðh4−C4H2−0\2−"SiMe1CH1PPri1#1ŁZrCl2 and its solutions[ To estimate the coordination ability of the
alkylation products\ reported ð4\ 5Ł[ Meanwhile\ com! diphenylphosphino group towards a Zr"IV# centre we
carried out the variable!temperature NMR studies of
compound 2 in CD1Cl1 and THF!d7[ Since the mono!
cyclopentadienyltrihalozirconiums "IV# are pre!
ꢀAuthor to whom correspondence should be addressed[
cursors of unsymmetrically ligated dicyclopentadienyl
complexes of Zr "IV#\ we were also interested in ela!
borating a convenient synthetic route to the simplest
E!mail] kdpÝorg[chem[msu[su^ fax "984# 8217735[
$ The second corresponding author^ e!mail] J[A[K[
HowardÝdurham[ac[uk
2778

2789
D[ P[ Krut|ko et al[
zirconocene of this type derived from 2\ "h4!C4H3 "see Scheme 0#[ There are certain reasons to suppose
CH1CH1PPh1#"h4!C4H4#ZrCl1 4[
RESULTS AND DISCUSSION
of "1!diphenylphosphinoethyl#cyclo!
that only isomer 1a is cleaved with ZrCl3 and produces
the desired complex 2[ Meanwhile\ the other isomers
1b\c[[[ are able to react in this manner only after their
slow conversion into 1a and may be involved into
Lewis acid induced diene polymerisation[ Thus\ even
determining of the initially required molar excess of
1 over ZrCl3 presents a problem and polymeric by!
products should be always expected[
Secondly\ if no THF is added\ the unreacted ZrCl3
is hardly removable from the reaction mixture[ Cap!
turing of ZrCl3 was directly con_rmed by the fact\
that the combined saturated mother liquors from the
fractional recrystallizations of crude 2 gave after
standing for 1 months at room temperature a small
amount of crystalline solid "ðh4]h0−"C4H3CH1
CH1PPh1#ZrClŁ1"m−Cl#2#¦1 ðZrCl3#1"m−Cl#1Ł1− 3[ The
structure of compound 3 was established by X!ray
di}raction analysis "see discussion below#[
To prepare the unsymmetrically ligated zirconocene
"h4!C4H3CH1CH1PPh1#"h4!C4H4#ZrCl1 4 derived from
2\ we _rst applied the conventional cyclo!
pentadienylation procedures[ However\ a reaction
between 2b and sodium cyclopentadienide either in
toluene or in THF leads to inseparable mixtures of all
the possible cyclopentadienyl ligand exchange prod!
ucts 4Ð6[ In toluene\ moreover\ zirconocenes 4Ð6 are
formed in a statistical ratio "1]0]0\ respectively# as
white crystalline solids "from ether# "see Scheme 2#[ In
Synthesis
pentadienyl complexes of zirconium "IV#
The SiÐC bond cleavage reaction in silylated cyclo!
pentadienes still remains among the most convenient
approaches
zirconiums "IV# derived from non!hindered cyclo!
pentadienes ð09Ł[ Since lithium "1!
to
monocyclopentadienyltrihalo!
diphenylphosphinoethyl#cyclopentadienide 0 is read!
ily available ð3Ł\ preparation of "1!diphenyl!
phosphinoethyl#trimethylsilylcyclopentadiene 1 meets
no problems "see Scheme 0#[
Mixing of equimolar amounts of 1 and ZrCl3 in
toluene leads to a complete dissolution of the metal
tetrahalide "supposedly caused by initial coordination
of ZrCl3 with the PPh1!groups of 1#\ followed by a
rapid formation of a thick white precipitate[ This pre!
cipitate
presents
crude
ðh4]h0!"1!diphenyl!
phosphinoethyl#cyclopentadienylŁtrichlorozirconium
"IV# 2[ The crude product 2 can be puri_ed both as
an unsolvated form 2a in a very low yield "fractional
recrystallizations from dichloromethane# or\ better\ as
an adduct with one molecule of tetrahydrofuran
"THF# 2b "recrystallization from THF# "see Scheme
1#[ Contrary to the reported for C4H4ZrCl2 ð00Ł\
adduct 2b is thermally stable in a THF solution even
at 89>C "sealed evacuated NMR!tube\ 5 hours#[
contrast\
the
application
of
trimethyl!
cyclopentadienyltin as a gentle cyclopentadienylating
agent gives excellent results and pure zirconocene 4 is
isolated in a good yield[
It is a well known fact that C4H4Na is capable of
introducing more than two cyclopentadienyl ligands
to Zr "IV# centre ð01Ł[ We believe that the observed
ligand randomisation is caused by the traces of
triscyclopentadienylzirconium "IV# species which are
We suppose that the considerable amount of
impurities in crude 2 and the di.culties of its puri!
_cation in the unsolvated form 2a are caused by two
main factors[ First of all\ compound 1 presents an
equilibrium mixture of isomers with allylic "1a# or
vinylic "1b\c[[[# position of the Me2Si!group[ At room
temperature\ the 0H NMR spectroscopically esti! generated when initial 2b and product 4 compete for
mated molar ratio of 1a to 1b\c[[[ is approximately 3]0 C4H−4 in the reaction mixture[ When the reaction is
Scheme 0[

"1!Diphenylphosphinoethyl#cyclopentadienyl complexes of zirconium "IV#
2780
Scheme 1[
performed in toluene\ the initially low solubility of are listed in Table 0[ The molecular structure of 2b
C4H4Na increases\ due to liberation of THF from 2b[ "_rst modi_cation# is shown in Fig[ 0[
As far as 2b is only moderately soluble in toluene\
considerable excess of free cyclopentadienide appears
in the solution\ and\ thus\ cyclopentadienyl ligand
exchange is complete in this case[ In contrast to
C4H−4 \ Me2SnC4H4 does not attack 4 at all\ so
triscyclopentadienylzirconium "IV# species are not
generated and no products of cyclopentadienyl ligand
exchange are formed[
Second modi_cation of 2b "crystallised from THF#
The unit cell contains only one independent
molecule[ The coordination environment of the cen!
tral Zr atom is quite close to that found for the _rst
crystalline modi_cation of 2b[ However\ the con!
formation of phosphino!substituent is completely
di}erent from the previous one "di}erent rotations
around PhÐP bond#[ For the _rst modi_cation of 2b\
all four torsion angles between the planes of phenyl
rings and exocyclic PÐC bonds lie within a range 32[9Ð
35[9>[ As for the second modi_cation\ the same angles
are equal to 4[6 and 89[0>[ Selected bond lengths and
angles are listed in Table 0[ The molecular structure
of 2b "the second modi_cation# is shown in Fig[ 1[
For both modi_cations of 2b\ the Zr atoms possess
a distorted octahedral coordination assuming that Cp!
ligands occupy one site[ The cyclopentadienyl rings
and THF molecules lie in the apical positions while
the phosphino!groups occupy equatorial ones[ The
mean deviation of the Zr atom from the equatorial
X!RAY CRYSTAL STRUCTURE
DETERMINATION OF ðh4]h0!
"C4H3CH1CH1PPh1#ŁZrCl2 = THF 2b AND
"ðh4]h0−"C4H3CH1CH1PPh1#ZrClŁ1
"m−Cl#2#¦1 ð"ZrCl3#1"m−Cl#1Ł1−
3
The structures of two di}erent crystalline modi!
_cations of 2b and ionic complex 3 were determined
by X!ray analysis[
First modi_cation of 2b "crystallised from CH1Cl1#
Ä
plane towards Cp!ligand is 9[38 A[ This polyhedron
The unit cell contains two independent molecules
with similar geometrical parameters[ These molecules
seem to be related by the superposition of the rotation
around the b!axis and 0:3!translation along the same
direction[ Thus\ the correctness of the unit cell dimen!
sions "doubling of axis#\ possibility of twinning and
the space group determination have been specially
checked[
is preferred for monocyclopentadienyl complexes of
Zr"IV# ð0\ 5\ 02Ð07Ł\ except for the cases when the
latter is prohibited by the steric requirements of the
substituted Cp!ligands ð09c\ 08Ł[ Analysis of the Cam!
bridge Structural Database "Release] October 0885#
ð19Ł shows that the ZrÐCl distances "1[3510"00#Ð
Ä
1[4027"09# A# in 2b are of normal values for terminal
Zr"IV#ÐCl bonds in monocyclopentadienyl complexes
The arrangement of molecules in the unit cell is such
that the ZrÐP directions are approximately parallel to
the b!axis "6[7 and 4[2>#[ The orthogonal least!squares
_tting of one independent molecule to the other\ based
on the positions of all non!hydrogen atoms "except
carbons of THF# resulted in an r[m[s[ deviation
Ä
"1[246Ð1[431 A#[ The ZrÐO"THF# bonds "1[249"2#Ð
Ä
1[2502"01# A# are noticeably shorter than it was found
for the same apical bonds in "CpR#ZrCl2 = 1THF
Ä
Ä
"R1
H\ 1[282"2# A\ R Me\ 1[266"1# A# ð02Ł[
1
Ä
9[96 A[ The greatest di}erences were observed for the Crystal structure of complex 3
conformations of the coordinated THF molecules\ as
far as one of them exhibits disorder of the envelope
The crystal structure of 3 is shown in Fig[ 2[ Selected
carbon atom C"72#[ Selected bond lengths and angles bond lengths and angles are listed in Tables 1 and 2\

2781
D[ P[ Krut|ko et al[
Scheme 2[
Ä
Table 0[ Selected bond lengths "A# and angles "># for 2b
First modi_cation
Molecule B
Second modi_cation
Molecule A
1[240"2#
Zr"0#ÐO"0#
Zr"0#ÐCl"01#
Zr"0#ÐCl"02#
Zr"0#ÐCl"00#
Zr"0#ÐP"0#
Zr"0#ÐPL"0#ꢀ
Zr"1#ÐO"1#
Zr"1#ÐCl"11#
Zr"1#ÐCl"12#
Zr"1#ÐCl"10#
Zr"1#ÐP"1#
Zr"1#ÐPL"1#ꢀ
O"1#ÐZr"1#ÐCl"11#
O"1#ÐZr"1#ÐCl"12#
O"1#ÐZr"1#ÐCl"10#
O"1#ÐZr"1#ÐP"1#
Cl"11#ÐZr"1#ÐCl"12#
Cl"11#ÐZr"1#ÐCl"10#
Cl"12#ÐZr"1#ÐCl"10#
Cl"11#ÐZr"1#ÐP"1#
Cl"12#ÐZr"1#ÐP"1#
Cl"10#ÐZr"1#ÐP"1#
1[249"2#
1[3510"00#
1[3794"09#
1[4950"09#
1[7696"00#
1[121"1#
70[42"7#
67[99"7#
65[42"7#
68[14"6#
82[48"3#
89[44"3#
042[17"3#
047[86"2#
89[69"2#
65[66"2#
ZrÐO
1[2502"01#
1[3718"4#
1[3677"4#
1[3870"4#
1[7363"4#
1[125"0#
68[49"2#
67[87"2#
65[58"2#
70[76"2#
80[76"1#
85[16"1#
041[31"1#
050[22"1#
72[31"1#
79[38"1#
1[3634"00#
1[3797"09#
1[4027"09#
1[7618"00#
1[118"1#
70[60"6#
67[03"6#
65[08"6#
66[76"6#
89[48"3#
80[51"3#
042[52"3#
047[55"2#
80[14"2#
66[48"2#
ZrÐCl"1#
ZrÐCl"2#
ZrÐCl"0#
ZrÐP
ZrÐPLꢀ
O"0#ÐZr"0#ÐCl"01#
O"0#ÐZr"0#ÐCl"02#
O"0#ÐZr"0#ÐCl"00#
O"0#ÐZr"0#ÐP"0#
Cl"01#ÐZr"0#ÐCl"02#
Cl"01#ÐZr"0#ÐCl"00#
Cl"02#ÐZr"0#ÐCl"00#
Cl"01#ÐZr"0#ÐP"0#
Cl"02#ÐZr"0#ÐP"0#
Cl"00#ÐZr"0#ÐP"0#
OÐZrÐCl"1#
OÐZrÐCl"2#
OÐZrÐCl"0#
OÐZrÐP
Cl"2#ÐZrÐCl"1#
Cl"1#ÐZrÐCl"0#
Cl"2#ÐZrÐCl"0#
Cl"1#ÐZrÐP
Cl"2#ÐZrÐP
Cl"0#ÐZrÐP
ꢀ PL"0# and PL"1# mean least!squares planes of the cyclopentadienyl rings[
respectively[ The asymmetric unit consists of posi! Zr1"m!Cl#2 motif was reported for several neutral com!
tively charged dimeric particle "ðh4]h0!"C4H3CH1 plexes of zirconium tetrachloride ð11Ł[
CH1PPh1#ZrClŁ1"m!Cl#2#¦ and a half of the centro!
Both zirconium atoms have a distorted octahedral
symmetric ð"ZrCl3#1"m!Cl#1Ł1! dianion[ In addition\ the coordination[ The apical bridging bonds Zr"l#ÐC0"4#
crystal lattice contains disordered CH1Cl1 molecule[ and Zr"1#ÐC0"2# are signi_cantly longer "1[6254"03#
Ä
The
central
"ðh4]h0!"C4H3CH1CH1PPh1#ZrClŁ1 and 1[622"1# A# than four equatorial non!terminal ZrÐ
"m!Cl#2#¦ unit represents the second example of mono! Cl bonds "1[4378"03#Ð1[5143"03# A#[ Previously we
Ä
cyclopentadienyl zirconium complex containing three have observed the same e}ect for similar complexes
bridging chlorine atoms ð10Ł[ However\ the same "h4]h0!C4Me3CH1CH1EMe#ZrCl2\ "E
S\ O# ð03Ł[ Of
1

"1!Diphenylphosphinoethyl#cyclopentadienyl complexes of zirconium "IV#
2782
Fig[ 0[ Molecular structure of 2b "_rst modi_cation#[ Displacement ellipsoids are shown at 49) probability level[ Hydrogen
atoms are omitted for clarity[
of neutral complex ðh4−C4H2−0\2−"SiMe1CH1
i
Ä
PPr 1#1ŁZrCl2 "1[786"0#\ 1[760"0# A# ð5Ł[ The latter can
be explained by the in~uence of the positive charge of
the "ðh4]h0!"C4H3CH1CH1PPh1#ZrClŁ1"m!Cl#2#¦ unit[
NMR study of the dynamic behaviour of complex 2 in
solutions
To determine the coordination ability of the pen!
dant phosphine group in 2a and 2b in solvating and
non!solvating solvents we performed the variable!
temperature NMR spectroscopy investigation of the
samples of 2a in CD1Cl1 and 2b both in THF!d7 and
0
in CD1Cl1[ The signals in the H and 02C!"0H# NMR
Fig[ 1[ Molecular structure of 2b "second modi_cation#[ Dis!
placement ellipsoids are shown at 49) probability level[
Hydrogen atoms are omitted for clarity[
spectra of complexes 2 and 4 "see Experimental# were
assigned on the basis of the homonuclear Overhauser
e}ect\ coupled 02C spectra and selective heteronuclear
decoupling experiments[
The value of 20P chemical shift is a good criterion
Ä
interest\ the longer Zr!"m!Cl# distance "1[683"6# A# was for the presence or absence of the ZrÐP coordination
found in the structure of closely related anionic bond[ Values close to those of free alkyl!
complex
"ðh4!"C4H3CH1CH
1
CH1#ZrCl1Ł1"m!Cl#2#! diphenylphosphines "d ca!04 ppm# are characteristic
ðLi"DME#Ł¦ ð10Ł[
of a non!coordinated PPh1!group\ while the ZrÐP
Ä
The ZrÐP distances "1[791"1#\ 1[706"1# A# are coordination results in the low _eld shifting of the
noticeably shorter than those found in the structure signal up to d ca 4Ð7 ppm[ The similar di}erences

2783
D[ P[ Krut|ko et al[
Fig[ 2[ Molecular structure of 3[ Displacement ellipsoids are shown at 49) probability level[ Hydrogen atoms and solvent
CH1Cl1 molecule are omitted for clarity[ Superscript symbol {{I|| indicates symmetry equivalent atoms[
Ä
Table 1[ Selected bond lengths "A# for 3
Zr"0#ÐCl"1#
Zr"0#ÐC"2#
Zr"0#ÐC"1#
Zr"0#ÐC"3#
Zr"0#ÐC"0#
Zr"0#ÐC"4#
Zr"0#ÐCl"2#
Zr"0#ÐCl"3#
Zr"0#ÐCl"4#
Zr"0#ÐP"1#
P"1#ÐC"6#
P"1#ÐC"10#
P"1#ÐC"20#
C"0#ÐC"1#
C"0#ÐC"4#
C"1#ÐC"2#
C"2#ÐC"3#
C"3#ÐC"4#
C"4#ÐC"5#
C"5#ÐC"6#
Zr"2#ÐCl"03#
Zr"2#ÐCl"00#
Zr"2#ÐCl"09#
1[397"1#
1[355"5#
1[381"5#
1[384"4#
1[416"5#
1[436"4#
1[4378"03#
1[5143"03#
1[6254"03#
1[706"1#
0[729"5#
0[715"5#
0[720"5#
0[288"8#
0[315"7#
0[393"8#
0[391"7#
0[303"7#
0[409"7#
0[410"7#
1[272"1#
1[286"1#
1[305"1#
Zr"1#ÐCl"0#
Zr"1#ÐC"02#
Zr"1#ÐC"01#
Zr"1#ÐC"03#
Zr"1#ÐC"00#
Zr"1#ÐC"04#
Zr"1#ÐCl"2#
Zr"1#ÐCl"3#
Zr"1#ÐCl"4#
Zr"1#ÐP"0#
P"0#ÐC"40#
P"0#ÐC"30#
P"0#ÐC"06#
C"00#ÐC"04#
C"00#ÐC"01#
C"01#ÐC"02#
C"02#ÐC"03#
C"03#ÐC"04#
C"04#ÐC"05#
C"05#ÐC"06#
Zr"2#ÐCl"01#
Zr"2#ÐCl"02#a
Zr"2#ÐCl"02#
1[300"1#
1[378"5#
1[384"5#
1[402"5#
1[414"5#
1[441"5#
1[622"1#
1[5055"02#
1[4419"03#
1[791"1#
0[721"5#
0[810"5#
0[718"5#
0[319"8#
0[323"8#
0[286"8#
0[300"8#
0[308"7#
0[493"7#
0[410"7#
1[316"1#
1[4865"03#
1[531"1#
aSymmetry transformation used to generate equivalent atoms] −x¦0\ −y\ −z[

"1!Diphenylphosphinoethyl#cyclopentadienyl complexes of zirconium "IV#
2784
Table 2[ Selected bond angles "># for 3
Cl"1#ÐZr"0#ÐCl"2# 83[63"4#
Cl"1#ÐZr"0#ÐCl"3# 041[21"4#
Cl"2#ÐZr"0#ÐCl"3# 66[93"3#
Cl"1#ÐZr"0#ÐCl"4# 67[70"4#
Cl"2#ÐZr"0#ÐCl"4# 65[17"3#
Cl"3#ÐZr"0#ÐCl"4# 62[46"3#
Cl"0#ÐZr"1#ÐCl"2# 67[97"4#
Cl"0#ÐZr"1#ÐCl"3# 041[02"4#
Cl"2#ÐZr"1#ÐCl"3# 63[95"3#
Cl"0#ÐZr"1#ÐCl"4# 84[83"4#
Cl"4#ÐZr"1#ÐCl"2# 65[29"3#
Cl"3#ÐZr"1#ÐCl"4# 65[72"3#
Cl"1#ÐZr"0#ÐP"1#
Cl"2#ÐZr"0#ÐP"1#
Cl"3#ÐZr"0#ÐP"1#
Cl"4#ÐZr"0#ÐP"1#
099[22"4#
036[46"4#
65[21"3#
67[69"3#
Cl"0#ÐZr"1#ÐP"0#
Cl"4#ÐZr"1#ÐP"0#
Cl"2#ÐZr"1#ÐP"0#
Cl"3#ÐZr"1#ÐP"0#
099[59"4#
036[30"4#
68[89"3#
64[33"3#
Zr"0#ÐCl"2#ÐZr"1# 78[44"3#
Zr"1#ÐCl"3#ÐZr"0# 89[38"3#
Zr"1#ÐCl"4#ÐZr"0# 78[30"3#
C"10#ÐP"1#ÐC"20# 093[0"2#
C"30#ÐP"0#ÐC"06# 095[9"2#
C"30#ÐP"0#ÐC"40# 094[9"2#
C"06#ÐP"0#ÐC"40# 092[8"2#
C"10#ÐP"1#ÐC"6#
C"20#ÐP"1#ÐC"6#
C"10#ÐP"1#ÐZr"0#
C"20#ÐP"1#ÐZr"0#
C"6#ÐP"1#ÐZr"0#
090[5"2#
095[0"2#
019[1"1#
008[8"1#
091[3"1#
C"30#ÐP"0#ÐZr"1#
C"06#ÐP"0#ÐZr"1#
C"40#ÐP"0#ÐZr"1#
019[7"1#
099[8"1#
007[0"1#
in d"20P# shifts of coordinated and non!coordinated
phosphino groups "Dd ca 19 ppm# in half!sandwich
complexes ðh4−C4H2−0\2−"SiMe1CH1PPri1#1ŁZrR2
"R2 Cl2\ Cl1"CH1Ph# and Me2# were reported pre!
1
viously ð5Ł[
Both non!solvated 2a and solvated 2b forms of 2 in
CD1Cl1 possess coordinated diphenylphosphino
groups "d"20P# from 5 to 7 ppm\ compare with
d"20P#−03[2 ppm for 4\ "see Table 3##[ The tem!
perature decrease down to −69>C does not a}ect
considerably the NMR spectra of both 2a and 2b\ that
points to the retention of ZrÐP coordination bond
over the whole temperature range studied[
Scheme 3[
Distinct deshielding of both the H6 and C6 signals
in 0H and 02C!"0H# NMR spectra of 2 in respect to 4
provides an additional proof that the ZrÐP coor!
dination does take place in the half sandwich complex
2[
is rather evident due to the close similarity of its NMR
parameters to that observed in CD1Cl1 "see Table 3#[
The second component 2c of the equilibrium mixture
exhibits no ZrÐP coordination "d"20P#½ −04 ppm#[
As far as the adducts of "h4!C4H3R#ZrCl2 = 1THF\
All these data on the behaviour of 2 in the non!
solvating CD1Cl1 media are in a good agreement with
those on the structure of the monocyclopentadienyl
complex ðh4−C4H2−0\2−"SiMe1CH1PPri1#1ŁZrCl2 in
toluene solution\ in which the zirconium center is
hexacoordinated over a wide temperature range ð5Ł[
In a THF solution\ the situation is markedly dif!
ferent[ In this case compound 2 presents an equi!
librium mixture of two forms 2b and 2c "see Scheme
"R H\ Me# are well known ð04Ł\ a structure of an
1
adduct with two molecules of THF may be assigned
to complex 2c with a high degree of probability[ The
observed two!site exchange becomes fast on the NMR
time scale at the temperatures exceeding 9>C[ The
content of 2c increases from ½29) at −29>C up to
½49) at −69>C\ that may correspond to the greater
negative DH values "and more strong bonding\ respec!
tively# of Zr!OR1 than Zr!PR2 coordination bond for!
mation for cyclopentadienyltrichlorozirconiums "IV#[
So\ the NMR spectroscopically observed exchange
between 2b and 2c appears to be an example of a
reversible solvent promoted intramolecular dis!
sociation!coordination of a pendant side chain func!
tionality[
0
3#[ The variable!temperature H and 20P!0"H# NMR
spectra of compound 2 in THF!d7 are depicted in Figs
3 and 4ꢀ[ For comparison\ the 0H NMR spectrum of
adduct 2b in CD1Cl1 at −69>C is given in Fig[ 5[ In
this equilibrium\ the participation of monoadduct 2b
ꢀ The assignment of the signals in 0H NMR spectra
depicted in Fig[ 3 to 2b and 2c was performed on the basis
of the homonuclear decoupling experiments and the tem!
perature dependent changes in their relative intensities[
We must admit here that no process of this type
was observed in the cases of !OMe and !SMe side
chain
functionalized
complexes
"h4]h0!C4Me3
CH1CH1EMe#ZrCl2\ "E
1
S\ O# ð03Ł and "h4]h0!

2785
D[ P[ Krut|ko et al[
Fig[ 3[ Variable!temperature 0H NMR spectra of 2b and 2c in THF!d7[ C4H3 and CH1CH1 regions are shown[
C4H3CH1CH1OMe#ZrCl2 ð12Ł in THF[ Thus\ the coor! agents "namely] diethyl ether and THF*with sodium
dination ability of PPh1!group towards Zr"IV# centre benzophenone ketyl\ toluene\ heptane and pentane*
seems to be less than that of methoxy! and methylthio! with Na!K alloy\ CH1Cl1 ! with P1O4 and then with
groups[
CaH1#\ degassed by multiple evacuations of the frozen
solvent "liq[ N1# and distilled in high vacuum directly
into the reaction vessel by trapping into liq[ N1[
EXPERIMENTAL
Initial materials and `eneral techniques
Spiroð1\3Łheptadiene!3\5
pentadienyltin ð14Ł
nylphosphinoethyl#cyclopentadienide ð3Ł
ð13Ł\
and lithium
trimethylcyclo!
"1!diphe!
were
0
All operations were performed in evacuated sealed prepared as described previously^ lithium diphenyl!
glass vessels[ The solvents employed "and their per! phosphide was prepared as a 9[5 M solution in THF
deuterated analogues# were dried with conventional by metallation of diphenylphosphine with n!butyl!

"1!Diphenylphosphinoethyl#cyclopentadienyl complexes of zirconium "IV#
2786
Fig[ 4[ Variable!temperature 20P!"0H# NMR spectra of 2b and 2c in THF!d7[
Fig[ 5[ 0H NMR spectrum of 2b in CD1Cl1 at −69>C[ C4H3 and CH1CH1 regions are shown[

2787
D[ P[ Krut|ko et al[
Table 3[ Selected NMR parameters for 2aÐc and 4 at di}erent temperatures
Complex
Solvent
t\>C
d"20P#"ppm# d"H5#"ppm# d"H6#"ppm# d"C6#"ppm#
2a
2b
2b
2b
2c
4
CD1Cl1
CD1Cl1
CD1Cl1
THF!d7
THF!d7
THF!d7
29
29
−69
−69
−69
29
7[2
5[0
6[1
1[87Ð2[09a
21[1
21[7
1[84 "dt#
2[94 "q#
2[91 "q#
1[70 "dt#
1[72 "dt#
1[75 "q#
1[67 "q#
4[9
2[01 "q#
−04[6
−03[2
1[32 "br t#
1[27 "m#
18[2
abr[ m\ AA?BB?X spin system[
lithium in pentane\ washing the precipitate with the 016[3
" CHÐ#\ 017[5 "p!C in PPh1#\ 017[6 "d\
1
same solvent and taking it up with THF[ Tri! 2JCPꢁ5[1 Hz\ m!C in PPh1# 021[2 "
1
CHÐ#\ 022[0
CHÐ#\ 028[6
1
methylchlorosilane was re~uxed with and distilled "d\ JCPꢁ07[6 Hz\ o!C in PPh1#\ 023[1 "
1
0
from AlCl2 onto aluminium powder\ degassed and "d\ JCPꢁ04[2 Hz\ ipso!C in PPh1#\ 034[8 "d\
operated as it was described for the solvents[ Com! 2JCPꢁ01[5 Hz\ ꢁCCH1CH1P#^ 20P!"0H#] −03[1[
mercially available ZrCl3\ diphenylphosphine and
Me2SnCl were received from Merck and Aldrich[ 0H\
02C!"0H#\ and 20P!"0H# NMR spectra were recorded
ðh4]h0!"1!Diphenylphosphinoethyl#cyclopentadienylŁ
on a Varian VXR!399 spectrometer at 399\ 099\ and
trichloro"tetrahydrofuran#zirconium "IV# 2b
0
051 MHz\ respectively[ For H and 02C!"0H# spectra\
solvent resonances ð6[04 and 017[9 ppm "C5D5#\ 4[21
A solution of 5[18 g "06[84 mmol# of silylated cyclo!
and 42[7 ppm "CD1Cl1#\ 0[62 and 14[2 ppm "THF!d7#Ł
pentadiene 1 was added to a stirred suspension of
were used as internal reference standards[ For 20P!
3[07 g "06[84 mmol# of ZrCl3 in 39 ml of toluene at
"0H# spectra\ 74) H2PO3 was employed as an external
−19>C[ The reaction mixture was allowed to warm
reference[ The temperature of the spectrometer probe
up to room temperature\ with the solid tetrachloride
was calibrated by measuring the shift di}erence of the
meanwhile dissolved[ In 04 minutes a thick white pre!
methanol resonance in the 0H spectrum[ The elemental
cipitate formed[ The reaction mixture was stirred at
analysis was performed on the Carlo!Erba automated
49>C for an additional 1 hours and left to stay over!
analyzer[
night[ The precipitate was _ltered o}\ washed three
times with 49 ml portions of pentane and extracted
Synthetic procedures
with CH1Cl1[ The combined extracts were concen!
"1 ! Diphenylphosphinoethyl#"trimethylsilyl#cyclopenta! trated\ the precipitate _ltered o}\ washed twice with
diene 1 "a mixture of isomers#
49 ml portions of pentane and dried in high vacuum\
that yielded 5[89 g "03[4 mmol\ 70)# of crude complex
13[5 ml of 9[59 M solution of lithium "1!diphe! 2[ Recrystallization from the minimal amount of hot
nylphosphinoethyl#cyclopentadienide in THF THF\ followed by washing with ether and drying in
0
"03[6 mmol# was slowly added to a cooled "−19>C# high vacuum yielded 3[44 g "8[48 mmol\ 42)# of
vigorously stirred solution of 0[76 ml "0[59 g\ monoadduct 2b[ Anal[ found] C\ 49[49^ H\ 3[68^ anal[
03[6 mmol# of trimethylchlorosilane in 09 ml of THF[ calc[ for C12H15Cl2OPZr C\ 49[42^ H\ 3[60[ NMR
The reaction mixture was allowed to warm up to room "CD1Cl1\ 29>C# 0H] 0[48 "m\ 3H\ THF#\ 1[84 "dt\
2
temperature and left to stay overnight[ On removal of 2JHHꢁ5[7 Hz\ JHPꢁ10[9 Hz\ 1H\ H5#\ 2[94 "q\
1
the solvent by trapping it into liq[ N1\ the residue was 2JHHꢁ5[7 Hz\ JHPꢁ5[7 Hz\ 1H\ H6#\ 3[91 "m\ 3H\
2¦3
extracted with pentane\ the extract evaporated and THF#\ 5[37 "virtual t\
J
ꢁ4[5 Hz\ 1H\ H1\4#\ 5[47
HH
2¦3
the crude product puri_ed by distillation\ that gave "virtual t\
J
ꢁ4[5 Hz\ 1H\ H2\3#\ 6[33 "m\ 5H\ m!
HH
3[46 g "02[93 mmol\ 77[4)# of silane 1[ B[p[ 043>C and p!H in PPh1#\ 6[56 "m\ 3H\ o!H in PPh1#^ 02C] 12[7
0
1
"2 = 09−1 torr#[ Anal[ found] C\ 64[86^ H\ 6[71^ anal[ "dt\ JCHꢁ023 Hz\ JCPꢁ8[4 Hz\ C5#\ 14[3 "t\
calc[ for C11H16PSi] C\ 64[28^ H\ 6[65[ NMR "listed 0JCHꢁ023 Hz\ THF#\ 21[7 "dt\ JCHꢁ025 Hz\
0
for 1a# "C5D5\ 292 K# H] −9[09 "s\ 8H\ SiMe2#\ 1[23 0JCPꢁ10[2 Hz\ C6#\ 61[2 "t\ 0JCHꢁ038 Hz\ THF#\ 006[6
0
"m\ 1H\ CH1CH1P#\ 1[53 "q\ 2JHHꢁ7[9 Hz\ "d\ JCHꢁ067 Hz\ C2\3#\ 010[6 "d\ JCHꢁ065 Hz\ C1\4#\
0
0
2JHPꢁ7[9 Hz\ 1H\ CH1CH1P#\ 2[04 "br[ s\ 0H\ CH 018[9 "dd\ JCHꢁ050 Hz\ JCPꢁ7[7 Hz\ m!C in PPh1#\
0
2
0
"SiMe2##\ 5[96 "br[ s\ 0H\ 1CHÐ#\ 5[39 "br[ s\ 0H\ 029[7 "d\ JCHꢁ051 Hz\ p!C in PPh1#\ 020[5 "d\
1CHÐ#\ 5[37 "br[ s\ 0H\ 1CHÐ#\ 6[96 "m\ 5H\ m! and 0JCPꢁ14[9 Hz\ ipso!C in PPh1#\ 022[4 "d\ 2JCPꢁ5[9 Hz\
p!H in PPh1#\ 6[35 "m\ 3H\ o!H in PPh1#[ 02C!"0H#] C0#\ 022[6 "dd\ JCHꢁ050 Hz\ JCPꢁ8[3 Hz\ o!C in
0
1
−1[9 "SiMe2#\ 15[6 "d\ 1JCPꢁ06[8 Hz\ CH1CH1P#\ 18[9 PPh1#^ 20P!"0H#] 5[0[
0
"d\ JCPꢁ02[0 Hz\ CH1CH1P#\ 40[0 "CH"SiMe2##\
A sample of unsolvated complex 2a for NMR

Table 4[ Crystal data\ data collection\ structure solution and re_nement parameters for 2b and 3
Empirical formula
Formula weight
Colour\ habit
Crystal size:mm
Crystal system
Space group
C12H15Cl2OPZr 2b "_rst modi_cation#
435[87
C12H15Cl2OPZr 2b "second modi_cation#
435[87
Colourless block
9[29×9[14×9[19
Monoclinic
P1"0#:c
7[6099"1#
05[9390"2#
05[6368"2#
099[095"0#
1292[42"7#
3
0[466
9[897
0001
C67H65Cl13P3Zr5 3
1424[27
Colourless block
9[19×9[19×9[19
Monoclinic
P1"0#:n
00[2587"0#
06[6707"1#
12[6004"2#
091[949"0#
3577[19"8#
1
Colourless block
9[14×9[19×9[04
Monoclinic
P1"0#:n
6[8607"0#
23[3187"2#
06[0482"0#
81[324"0#
3694[31"7#
7
Ä
Unit cell dimensions] a:A
Ä
b:A
Ä
c:A
b:>
2
Ä
Volume:A
Z
Density "calculated#:g = cm−2
Absorption coe.cient:mm−0
F"999#
0[433
9[778
1113
0[685
0[326
1493
Di}ractometer
Siemens SMART CCD ð15Ł
Temperature:K
Radiation "l:A#
099[9"1#
099[9"1#
049[9"1#
Ä
graphite!monochromated Mo!Ka "9[60962#
Scan mode
v
v
v
Scan step "in v#:>
Time per step:sec
u range:>
9[2
19
9[2
04
9[2
39
0[07 to 15[99
0[66 to 16[37
0[33 to 16[42
Index ranges
−09²h²7−39²k²33−11²l²19
29799
8136 ðRintꢁ9[9506Ł
−00²h²09−19²k²05−10²l²10
05147
4170 ðRintꢁ9[9225Ł
−03²h²02−12²k²11−18²l²29
22600
09654 ðRintꢁ9[0006Ł
Re~ections collected
Independent re~ections
Data reduction
Siemens SAINT ð16Ł
Absorbtion correction
Min[ and Max[ transmission
Solution method
Empirical ð17Ł
9[582 and 9[797
9[518 and 9[783
9[592 and 9[674
Direct methods "SHELX!75# ð18Ł
Full!matrix least!squares on F1 "SHELXL!82# ð29Ł
4937:9:256
Re_nement method
Data:restraints:parameters
8913:9:612
09548:9:404
Weighting scheme w−0
ꢁ
s1"F1#¦"9[941P#1
0[956
s1"F1#¦"9[941P#1¦1[4946P where Pꢀ"1Fc1¦F1o#:2
0[976
s1"F1#¦13[5421P
0[114
Goodness!of!_t on F1
Final R indices ðIŁ1s"I#Ł
R indices "all data#
Extinction coe.cient
R0ꢁ9[9345\ wR1ꢁ9[9862
R0ꢁ9[9623\ wR1ꢁ9[0034
9[99995"7#
R0ꢁ9[9145\ wR1ꢁ9[9419
R0ꢁ9[9224\ wR1ꢁ9[9474
9[99045"03#
R0ꢁ9[9448\ wR1ꢁ9[9860
R0ꢁ9[0995\ wR1ꢁ9[0161
9[99994"4#
−2
Ä
Largest di}[ Peak and hole :e A
9[695 and −0[406 "near Zr atoms#
9[286 and −9[208 "near Zr atom#
0[911 and −9[896 "near Zr atom#
ꢀ

2899
D[ P[ Krut|ko et al[
experiments was prepared by fractional recrys!
tallizations of a portion of crude 2 from CH1Cl1[
Supplementary material available * Further details
of the crystal structure determinations of 2b and 3\ i[e
tables with all atomic coordinates\ thermal
parameters\ interatomic distances\ and structure
factors\ are available from authors[
ðh4!"1!Diphenylphosphinoethyl#cyclopentadienylŁ"h4!
cyclopentadienyl#dichlorozirconium "IV# 4
Acknowled`ements*This investigation was supported by
Russian Foundation for Basic Research "project No 85!92!
23121a#[ A[V[C[ thanks The Royal Society and The Uni!
versity of Durham for _nancial support[
A
solution of 9[20 g "0[10 mmol# of tri!
methylcyclopentadienyltin in 19 ml of toluene and a
suspension of 9[55 g "0[10 mmol# of 2b in 4 ml of tolu!
ene were mixed\ stirred at room temperature for 2
hours and then heated at 59>C for 1 hours[ The volatile
components were removed in high vacuum from hot
water bath "59>C# by trapping into liq[ N1[ The crude
product was washed on a glass _lter three times with
19 ml portions of heptane\ the residue was dried in
high vacuum and recrystallized from ether\ that gave
9[24 g "9[58 mmol\ 46[4)# of zirconocene 4[ Anal[
found] C\ 46[30^ H\ 3[51^ anal[ calc[ for C13H12Cl1PZr
C\ 46[02^ H\ 3[48[ NMR "THF!d7\ 29>C# 0H] 1[27 "m\
REFERENCES
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1H\ H6#\ 1[67 "q\ 2JHHꢁ7[1 Hz\ 2JHPꢁ7[1 Hz\ 1H\ H5#\
2¦3
5[16 "virtual t\
J
ꢁ4[1 Hz\ 1H\ H1\4#\ 5[27 "virtual
HH
3[ Kettenbach\ R[ T[\ Bonrath\ W[ and Butenschon\
Ã
2¦3
t\
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Or`anomet[ Chem[\ 0884\ 492\ 006[
PPh1#^ 02C] 16[3 "dt\ 0JCHꢁ017 Hz\ 1JCPꢁ08[6 Hz\ C5#\
18[2 "dt\ JCHꢁ017 Hz\ JCPꢁ01[2 Hz\ C6#\ 002[4 "d\
0
0
0JCHꢁ063 Hz\ C2\3#\ 005[4 "d\ JCHꢁ063 Hz\ C4H4#\
0
006[6 "d\ 0JCHꢁ063 Hz\ C1\4#\ 018[1 "dd\ 0JCHꢁ059 Hz\
2JCPꢁ5[9 Hz\ m!C in PPh1#\ 018[2 "d\ 0JCHꢁ059 Hz\ p!
C in PPh1#\ 022[5 "dd\ 0JCHꢁ048 Hz\ 1JCPꢁ07[6 Hz\ o!
C in PPh1#\ 024[6 "d\ JCPꢁ02[6\ C0#\ 028[7 "d\
2
0JCPꢁ04[9 Hz\ ipso!C in PPh1#^ 20P!"0H#] −03[2[
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15[00[0858^ Chem[ Abstr[\ 0860\ 64\ 77657^ "b#
X!ray investi`ation of complexes 2b and 3
Single crystals were prepared by crystallisation
from CH1Cl1 "the _rst modi_cation of 2b#\ THF "the
second modi_cation of 2b#\ and saturated mother
liquors from the fractional recrystallizations of crude
2 "complex 3#\ mounted in inert oil on a tip of glass
_bre and transferred to the cold nitrogen stream inside
the di}ractometer[ Crystal data\ data collection\ struc!
ture solution and re_nement parameters for 2b and 3
are listed in Table 4[
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ꢂ
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Bulletin\ 0885\ 34\ 0639[
In the case of _rst modi_cation\ the disordered car!
bon atom C"72# was re_ned isotropically\ all other
non!hydrogen atoms were re_ned with anisotropic
thermal parameters[ All hydrogen atoms were found
from di}erence Fourier syntheses and re_ned iso!
tropically\ except those attached to disordered carbon
atom[ They were placed in calculated positions "d"CÐ
Ä
H#ꢁ9[85 A# and re_ned using a riding model[
In the second case of 2b all non!hydrogen atoms
were re_ned with anisotropic thermal parameters[ All
hydrogen atoms were found from di}erence Fourier
syntheses and re_ned in an isotropic approximation[
As for compound 3\ all non!hydrogen atoms were
re_ned with anisotropic thermal parameters[ All
hydrogen atoms were placed in calculated positions
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Ä
"d"CÐH#ꢁ9[85 A# and re_ned using a riding model[

"1!Diphenylphosphinoethyl#cyclopentadienyl complexes of zirconium "IV#
2890
06[ Mu\ Ying[\ Piers\ W[ E[\ Macgillivray\ L[ R[ and
S[ I[\ Surmina\ L[ S[ and Raschupkina\ Z[ A[\ Zh[
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Nolte\ M[\ J[ Or`anomet[ Chem[\ 0882\ 348\ 096[
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0884[
19[ Allen\ F[ H[ and Kennard\ O[\ Chemical Desi`n 16[ SAINT Version 3[949[ Siemens Analytical X!ray
Automation News\ 0882\ 7\ 0[
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Instruments Inc[\ Madison\ Wisconsin\ USA\
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Siemens Analytical X!ray Instruments Inc[\
Madison\ Wisconsin\ USA\ 0880[
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12[ van der Zeijden\ A[ A[ H[\ Mattheis\ C[\ Frohlich\ 29[ Sheldrick\ G[M[\ SHELXL!82[ Program for the
R[ and Zippel\ F[\ Inor`[ Chem[\ 0886\ 25\ 3333[
13[ Ze_rov\ N[ S[\ Kuznetsova\ T[ S[\ Kozhushkov\
Re_nement of Crystal Structures[ University of
Gottingen\ Germany\ 0882[
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