Palladium (II) complexes of hybrid phosphine - Phosphine oxide ligands

Article abstract of DOI:10.1016/S0277-5387(98)00061-8

Complexes of the type [L₂PdCl₂] , where L = Ph₂PCH₂P (O) Ph₂ (dppmO) , Ph₂P (CH₂) ₂P (O) Ph₂ (dppeO) , Ph₂P (CH₂) ₃P (O) Ph₂ (dpppO) , Ph₂P (CH₂) ₄P (O) Ph₂ (dppbO) , and Ph₂PC₅H₄FeC₅H₄P (O) Ph₂ (dppfcO) , were prepared in high yield from Na₂ [PdCl₄] and 2 equiv. of the corresponding L in dichloromethane-methanol. All complexes, except for [ (dppfcO) ₂PdCl₂] , can exist as the cis and trans isomers, or mixtures of both, with the cistrans ratio decreasing in media of low polarity. The ferrocene containing complex, [ (dppfcO) ₂PdCl₂] , appeared to be exclusively trans in both the solid state and solution, as established by single crystal X-ray diffraction of its 1 : 3 benzene solvate. The ion exchange extraction of dichloromethane solutions of [ (dppmO) ₂PdCl₂] and [ (dppeO) ₂PdCl₂] with aqueous NaBF₄ furnished the corresponding cationic P,O-chelates, cis- [ (dppmO) ₂Pd] ² (BF^-₄)₂ and cis- [ (dppeO) ₂Pd] ² (BF^-₄)₂. Alternatively, these cations can be generated by the reaction between the chloro complexes, [ (dppmO) ₂PdCl₂] and [ (dppeO) ₂PdCl₂] , with Ag⁺. Single crystal X-ray diffraction of cis- [ (dppeO) ₂Pd] ² (BF^-₄)₂ revealed distinct conformations (a puckered chair and a distorted sofa) for the two chelate rings situated around each Pd atom. A polymeric, poorly soluble material, { [ (dpppO) ₂Pd] ² (BF^-₄)₂}_n, was isolated from the reaction between [ (dppO) ₂PdCl₂] and AgNO₃ NaBF₄, with both coordinated and free phosphoryl groups being present in the product (IR) . In dilute solutions of the { [ (dpppO) ₂Pd] ² (BF^-₄)₂}_n, depolymerization occurred, giving rise to the monomeric cationic chelate, cis- [ (dpppO) ₂Pd] ²(BF^-₄)₂.

Full text of DOI:10.1016/S0277-5387(98)00061-8

Polyhedron Vol[ 06\ No[ 07\ pp[ 2948Ð2969\ 0887
Þ 0887 Elsevier Science Ltd
Pergamon
All rights reserved[ Printed in Great Britain
9166Ð4276:87 ,08[99¦9[99
\
PII ] S9166Ð4276"87#99950Ð7
Palladium"II# complexes of hybrid phosphine*
phosphine oxide ligands
Randy J[ Coyle\a Yuri L[ Slovokhotov\bꢀ Mikhail Yu[ Antipinb and
Vladimir V[ Grushina$ꢀ
aDepartment of Chemistry\ Wilfrid Laurier University\ Waterloo\ Ontario\ Canada N1L 2C4
bInstitute of Organo!Element Compounds\ Russian Academy of Sciences\ 17 Vavilov St[\ B!223\ Moscow\
006702\ Russia
"Received 19 October 0886 ^ accepted 17 January 0887#
Abstract*Complexes of the type ðL1PdCl1Ł\ where L ꢁ Ph1PCH1P"O#Ph1 "dppmO#\ Ph1P"CH1#1P"O#Ph1
"dppeO#\ Ph1P"CH1#2P"O#Ph1 "dpppO#\ Ph1P"CH1#3P"O#Ph1 "dppbO#\ and Ph1PC4H3FeC4H3P"O#Ph1
"dppfcO#\ were prepared in high yield from Na1ðPdCl3Ł and 1 equiv[ of the corresponding L in dichloromethane!
methanol[ All complexes\ except for ð"dppfcO#1PdCl1Ł\ can exist as the cis and trans isomers\ or mixtures
of both\ with the cis:trans ratio decreasing in media of low polarity[ The ferrocene containing complex\
ð"dppfcO#1PdCl1Ł\ appeared to be exclusively trans in both the solid state and solution\ as established by single
crystal X!ray di}raction of its 0 ] 2 benzene solvate[ The ion exchange extraction of dichloromethane solutions
of ð"dppmO#1PdCl1Ł and ð"dppeO#1PdCl1Ł with aqueous NaBF3 furnished the corresponding cationic P\O!
chelates\ cis!ð"dppmO#1PdŁ1¦ "BF3−#1 and cis!ð"dppeO#1PdŁ1¦ "BF3−#1[ Alternatively\ these cations can be
generated by the reaction between the chloro complexes\ ð"dppmO#1PdCl1Ł and ð"dppeO#1PdCl1Ł\ with Ag¦[
Single crystal X!ray di}raction of cis!ð"dppeO#1PdŁ1¦ "BF3−#1 revealed distinct conformations "a puckered
chair and a distorted sofa# for the two chelate rings situated around each Pd atom[ A polymeric\ poorly soluble
material\ "ð"dpppO#1PdŁ1¦ "BF3−#1#n\ was isolated from the reaction between ð"dppO#1PdCl1Ł and AgNO2:
NaBF3\ with both coordinated and free phosphoryl groups being present in the product "IR#[ In dilute solutions
of the "ð"dpppO#1PdŁ1¦ "BF3−#1#n\ depolymerization occurred\ giving rise to the monomeric cationic chelate\
cis!ð"dpppO#1PdŁ1¦ "BF3−#1[ Þ 0887 Published by Elsevier Science Ltd[ All rights reserved
Keywords] bis!phosphine mono!oxides ^ palladium ^ chelates[
———————————————————————————————————————————————
The coordination chemistry of bis!phosphine mon! experimental procedure for the synthesis of this com!
oxides "BPMOs# of the general formula R1P!X! plex has been communicated[ The other complex\
P"O#R1\ where X ꢁ any divalent group\ e[g[ "CH1#n\ ð"dppmO#1PdCl1Ł "dppmO ꢁ Ph1PCH1P"O#Ph1#\ has
is still insu.ciently explored[ Although some BPMO
complexes with various metals have been reported ð0Ð
04Ł\ very little is known about palladium derivatives
of BPMOs[ Only two BPMO complexes of Pd have
been described in the literature[ One of them\
ð"dppeO#1PdCl1Ł "dppeO ꢁ Ph1P"CH1#1P"O#Ph1#\ has
been successfully used in catalyst ð09Ł[ However\ no
been reported ð5\02Ł but not characterized by any
spectral or structural means[ It is worth noting that
studying solution behavior of such complexes is
important because of their intriguing catalytic activity
ð09Ł and potential use in synthesis ð02Ł[ In the present
paper we report\ for the _rst time\ the detailed prep!
aration\ full characterization\ and some chemical reac!
tions of a series of palladium complexes containing
monoxides
of
bis"diphenylphosphino#methane
"dppmO#\ 0\1!bis"diphenylphosphino#ethane "dppeO#\
0\2!bis"diphenylphosphino#propane "dpppO#\ 0\3!
bis"diphenylphosphino#butane "dppbO#\ and 0\0?!
bis"diphenylphosphino#ferrocene "dppfcO#[
ꢀ To whom correspondence should be addressed[
$ Present address ] E[ I[ Du Pont de Nemours and Co[ Inc[\
Central Research and Development E217:295\ Experimental
Station\ Wilmington\ Delaware 08779!9217\ U[S[A[
2948

2959
R[ J[ Coyle et al[
rest of the spectra were obtained with D0 ꢁ 0 s[ As
RESULTS AND DISCUSSION
anticipated ð05Ł\ the cis:trans ratio for the equilibrated
Synthesis of ðL1PdCl1Ł "L ꢁ dppmO\ dppeO\ dpppO\ mixtures increased with solvent polarity "see Table 0#[
dppbO\ and dppfcO#
ð"dppmO#1PdCl1Ł[ No NMR spectral charac!
terization of this complex has appeared in the litera!
Adding methanolic Na1ðPdCl3Ł to
a
dichlo! ture[ According to our 20P NMR data "Table 0#\
romethane solution of a BPMO\ L\ "ca 1[0 equiv[# ð"dppmO#1PdCl1Ł in benzene is exclusively trans\
resulted in the formation of the corresponding whereas in methanol it is mostly cis\ with the cisÐtrans
ðL1PdCl1Ł in nearly quantitative yield "eqn "0##[ The ratio being 84 ] 4[ The resonances of both isomers are
isolation and puri_cation "if necessary# of the com! clearly seen in the 20P NMR spectra obtained in
plexes is described in the Experimental Section[
CH1Cl1 and CHCl2\ solvents of intermediate polarity
in comparison with benzene and MeOH[ The small
20PÐ20P coupling constants did not allow us to immedi!
ately assign the observed resonances to the cor!
responding isomers[ However\ the proper assignment
of the lines is easily made by comparison of the spectra
of ð"dppmO#1PdCl1Ł with those of its dppeO analogue
"see Table 0 and text below#[ In line with this assign!
ment of the 20P resonances are the patterns observed
All _ve compounds are stable crystalline solids
which can be stored at room temperature in air for
months with no sign of decomposition[ All of them are
soluble in dichloromethane and chloroform\ slightly
soluble in benzene\ and insoluble in ether and alkanes[
The complexes of dppmO and dppeO are soluble in
methanol\ whereas those containing dpppO and
dppbO are only sparingly soluble in this solvent[ The
dppfcO complex was found to be insoluble in alcohols[
0
in the H NMR spectra of the dppmO complex[ The
0H NMR spectrum of the ð"dppmO#1PdCl1Ł in CDCl2\
where the complex is 89) trans according to the 20P
NMR data\ contains a doublet of virtual triplets "JPÐ
H ꢁ 00[3 Hz ^ 1JPÐH¦3JPÐH ꢁ 6[3 Hz# at 2[8 ppm and a
shoulder at 2[7 ppm due to the minor amount of the
cis isomer[ In methanol!d3\ the cis geometry prevails
"ca 84)# and the resonance from the methylene pro!
tons appears at 3[2 ppm as a doublet of doublets with
JPÐH ꢁ 02[4 and 09[4 Hz[ This pattern was observed
only for the freshly prepared sample\ since the acidic
CH1 protons of the complex were found to undergo
facile H:D exchange with the CD2OD solvent[ As a
result\ the methylene resonance soon began to dim!
inish in intensity while transforming into a complex
multiplet\ and eventually disappeared altogether after
a few days[ As the H:D exchange occurred\ a number
of isotopomers "29[2Ð29[8 ppm# of varying intensities
were observed for the P0Pd resonance in the 20P
NMR spectrum\ due to the molecules containing the
CH1\ CHD\ and CD1 groups[
Solution behavior of ðL1PdCl1Ł "L ꢁ dppmO\ dppeO\
dpppO\ dppbO\ and dppfcO#
Like many square!planar PdII compounds of the
general formula ðL1PdCl1Ł ð05Ł\ complexes with
L ꢁ dppmO\ dppeO\ dpppO\ and dppbO exist in solu!
tion as mixtures of cis and trans isomers "eqn "1#\
Table 0#[ At room temperature\ the isomers seem to
equilibrate much more readily "seconds# than their
monodentate tertiary phosphine counterparts[ This
remarkably facile cisÐtrans isomerization is likely due
to the presence of the phosphoryl groups\ whose oxy!
gen atoms are capable of intramolecularly coor!
dinating to the metal center[ Clearly\ this e}ect is
similar to the free!ligand catalysis in the cisÐtrans iso!
merization reactions of Pd"II# and Pt"II# complexes
ð05Ł[ As described below\ _rm evidence was obtained
for such weak and reversible Pd0O interactions[
ð"dppeO#1PdCl1Ł[ The 20P NMR spectrum of a solid
formulated as ð"dppeO#1PdCl1Ł = 1H1O was reported
ð2Ł to exhibit one singlet at 23[34 ppm[ In another
paper ð09Ł\ two resonances "19[03 and 22[98 ppm#
were observed in the 20P NMR spectrum of ð"dppe!
O#1PdCl1Ł in chloroform!d\ but no information was
provided on the multiplicity of these signals[ We found
that solutions of ð"dppeO#1PdCl1Ł in chloroform!d
contain both the cis and trans isomers\ as can be
clearly seen from the 20P NMR spectrum[ The trans
isomer exhibits a doublet of doublets at 08[8 ppm for
the P atom coordinated to the metal with 2JPÐP ꢁ 17[3
4
Hz and JPÐP ꢁ 14[8 Hz\ and a virtual triplet at 22[1
2
ppm for the phosphoryl group with JPÐP¦4JPÐ
Structures of the isomers and their distribution in P ꢁ 43[9 Hz[ This spectral pattern exhibiting the
0
various solvents were studied by H and 20P NMR remarkable long!range coupling is perfectly consistent
techniques[ To assure reliable 20P NMR integration with the trans geometry[ Two doublets at 29[3 and
measurements\ the spectra of the _rst few samples 21[7 ppm "JPÐP ꢁ 45[0 Hz# were also found in the
were run with delay times D0 ꢁ 0\ 2\ and 4 s[ Since no spectrum\ obviously due to the cis isomer[ Essentially
changes in the integration ratios were noticed\ the the same pattern was observed for solutions of ð"dppe!

Palladium"II# complexes of hybrid phosphine
2950
Table 0[ 20P NMR data for palladium complexes of the type ðL1PdCl1Ł in di}erent solvents
20P NMR\ d
L
Solvent
Geometry
P0Pd
P1O
trans ] cis
099 ] 9
89 ] 09
54 ] 24
4 ] 84
099 ] 9
74 ] 04
74 ] 04
59 ] 39
*
dppmO
Benzene
trans
cis
trans
cis
trans
cis
trans
cis
trans
cis
trans
cis
trans
cis
trans
cis
trans
cis
trans
cis
trans
cis
trans
cis
trans
cis
trans
cis
trans
cis
trans
cis
00[7
None
00[7
11[4
00[7
10[4
01[9
29[5
08[8
None
08[8
29[3
08[6
18[2
19[2
20[9
15[5
None
13[3
13[8
13[1
14[9
33[0
33[0
18[6
None
22[1
21[7
20[4
20[1
26[4
27[9
Chloroform
Dichloromethane
Methanol
dppeO
dpppO
dppbO
dppfcO
Benzene
Chloroform
Dichloromethane
Methanol
Benzene
Insoluble
in benzene
05[2
Chloroform
Dichloromethane
Methanol
21[1
21[3
29[7
29[6
26[5
27[9
17[3
None
21[4
21[1
29[8
29[8
26[1
26[4
14[4
None
17[3
None
16[3
None
74 ] 04
79 ] 19
44 ] 34
099 ] 9
74 ] 04
79 ] 19
34 ] 44
*
29[6
05[1
17[4
05[8
29[6
05[7
None
05[6
17[3
05[6
16[5
06[7
18[5
04[1
None
04[0
None
04[2
None
Benzene
Chloroform
Dichloromethane
Chloroform:methanol
0 ] 09
Benzene
trans
cis
trans
cis
trans
cis
trans
cis
Chloroform
Dichloromethane
Methanol
*
*
Insoluble
in methanol
*
O#1PdCl1Ł in dichloromethane[ It is worth noting that fact\ the 20P NMR spectral patterns for the
the coupling constant measured for the cis isomer is ð"dpppO#1PdCl1Ł and ð"dppbO#1PdCl1Ł are very simi!
close to the values of 36[2Ð37[0 Hz obtained for the lar\ displaying almost identical parameters "Table 0#[
free ligand ð06Ł[ As anticipated\ only the trans isomer The chemical shift values provide information for the
was found in benzene solutions of the complex\ easy and unambiguous assignment of the resonances[
whereas both the cis and trans isomers were present Because of poor solubility no 20P NMR spectra were
when methanol was used as the solvent "Table 0#[ obtained for solutions of ð"dpppO#1PdCl1Ł in benzene
The portionwise addition of water to the methanol and ð"dppO#1PdCl1Ł in methanol[ However\ both iso!
solution lead to a noticeable increase in the cisÐtrans mers of ð"dppbO#1PdCl1Ł in approximately equal
ratio[
quantities were observed in a 0 ] 09 chloroformÐmeth!
ð"dpppO#1PdCl1Ł and ð"dppbO#1PdCl1Ł[ As the num! anol solution of the complex[
ber of methylene groups separating the PIII and PV
ð"dppfcO#1PdCl1Ł[ Like the two preceding
atoms increases\ the spectral behavior of the cor! complexes\ ð"dppfcO#1PdCl1Ł is a new compound[ The
responding Pd complexes becomes less distinct[ In 20P NMR spectra of this complex suggest that in

2951
R[ J[ Coyle et al[
benzene\ chloroform\ and dichloromethane it exists as and 9[91 _ longer than those in the trans!ðL1PdCl1Ł\
0
only one isomer[ In line with this is the H NMR where L ꢁ PPh2 ð10\11Ł and dppeO ð00Ł\ respectively[
spectrum of the complex "see Experimental Section#[ This elongation may be due to the presence of the
Virtual insolubility of the ð"dppfcO#1PdCl1Ł in polar electron!rich\ bulky ferrocene substituents on the
media\ methanol included\ prevented its charac! coordinated phosphorus atoms[ Among other fea!
terization by NMR in such solvents[
tures of the molecular geometry of the ð"dppfcO#1
As clearly seen from the above data\ for the com! PdCl1Ł = 2C5H5 it is worth noting the small di}erence
plexes ðL1PdCl1Ł\ where L ꢁ dppmO\ dppeO\ dpppO\ between the C0P "phosphine# and C0P "phos!
and dppbO\ the existence of both cis and trans isomers phoryl# bond lengths of 0[793Ð0[726"4# and 0[684Ð
0
was reliably established by 20P and H NMR tech! 0[704"4# _\ respectively[ No shortened intramolecular
niques[ This was not the case\ however\ with the or intermolecular contacts were found in the structure
dppfcO complex\ for which only one isomer was found of the complex[
to exist in various solvents[ Due to the steric bulk of
dppfcO ligand the trans geometry for the ð"dppfcO#1
PdCl1Ł seemed to be more plausible[ This conjecture
Cationic palladium bis!chelates\ ð"BPMO#1PdŁ1¦
was examined by X!ray analysis of the compound[
The literature ð09Ð01Ł data and the data described
above provide no _rm evidence for any coordination
Sin`le crystal X!ray diffraction study of ð"dppfcO#1
PdCl1Ł
of the phosphoryl group oxygen atoms to the metal
center in complexes of the general formula
ð"BPMO#1PdCl1Ł in the solid state or in solution[ It
was proposed ð09Ł that such interactions between the
phosphoryl oxygen atoms and the metal center might
be responsible for the unique regioselectivity observed
in the hydroxycarbonylation reaction of ole_ns cat!
alyzed by ð"dppeO#1PdCl1Ł[ Higgins\ Shaw\ and
Taylor ð5Ł demonstrated that ð"dppmO#1PdCl1Ł can be
forced to lose the chloro ligands when treated with 1
equiv[ of AgNO2[ According to their 20P NMR data\
the resulting cationic complex\ ð"dppmO#1PdŁ1¦\ is a
cis!chelate with both oxygens of the phosphoryl
groups coordinated to the metal ð5Ł[ Because of the
ability of Ag¦ to trap Cl− e.ciently this result should
not be regarded as evidence for the existence of equi!
librium 2\ either[
As a new compound ð07Ł\ the dppfcO ligand has
been characterized by elemental analysis and NMR
spectral data ð08Ł[ Although we had attempted a single
crystal X!ray di}raction study of dppfcO twice\ crys!
tallographic disorder did not allow us to obtain accu!
rate molecular parameters of the ligand[ X!ray quality
crystals of ð"dppfcO#1PdCl1Ł were obtained by diluting
its saturated dichloromethane solution with benzene
which caused slow precipitation of the complex as
a 0 ] 2 benzene solvate[ Crystallographic parameters\
data collection\ and structure re_nement summary are
presented in Table 1[ Table 2 lists the most important
bond lengths and bond angles for the complex[ As
anticipated\ the complex has a centrosymmetric trans!
structure "Fig[ 0# with almost ideal square!planar con!
_guration around the Pd atom[ One of the solvate
benzene molecules occupies a general position in the
crystal\ whereas the second one lies on the center of
symmetry[ Both disubstituted ferrocene units possess
slightly twisted conformation\ often called {{skew
rings||\ which is dictated by steric requirements of
diphenylphosphino and diphenylphosphoryl groups[
The pseudo torsion angle P"0#Ðring 0"center#Ðring
1"center#ÐP"1# is equal to 022[6>\ whereas at the ideal
eclipsed conformation of the rings in ferrocene this
angle is 033>[ Both P"0# and P"1# slightly deviate from
the mean planes of the corresponding 4!membered
First evidence for equilibrium 2 was found in our
rings by 9[925 and 9[911 _\ respectively[ The inter! work[ Washing
a dichloromethane solution of
planar angle between the rings is 3[0>[
ð"dppmO#1PdCl1Ł with a few portions of 39) aqueous
Although the dppfcO ligand is certainly bulkier NaBF3 at room temperature lead to the quantitative
than dppeO or PPh2\ the Pd0Cl and the Pd0P bond "20P NMR# formation of ð"dppmO#1PdŁ "BF3#1 which
distances in ð"dppfcO#1PdCl1Ł are only slightly longer was subsequently isolated in 63) yield[ The 20P NMR
than those of trans!ð"dppeO#1PdCl1Ł00 and trans! characterises of this complex were identical to those
ð"Ph2P#1PdCl1 ð10\11Ł[ Thus\ the Pd0Cl bond length described for the cationic species obtained by the reac!
of 1[295 "0# _ was found in ð"dppfcO#1PdCl1Ł\ whereas tion between ð"dppmO#1PdCl1Ł and AgNO2 ð5Ł[ The
the values of 1[181"0# _ ð00Ł and 1[170Ð1[185"0# synthesis of ð"dppeO#1PdŁ "BF3#1 from the cor!
ð10\11Ł have been reported for the dppeO ð00Ł and responding neutral dichloride and NaBF3 was carried
triphenylphosphine ð10\11Ł counterparts[ The Pd0P out in the same manner\ furnishing the cationic com!
bond in the dppfcO complex "1[236"0# _# is ca 9[90 plex in 85) isolated yield "eqn "3##[

Palladium"II# complexes of hybrid phosphine
2952
Table 1[ Crystallographic data for ð"dppfcO#1PdCl1Ł = 2C5H5 and ð"dppeO#1PdŁ "BF3#1
ð"dppfcO#1PdCl1Ł = 2C5H5
ð"dppeO#1PdŁ "BF3#1
Empirical formula
Formula weight
Temperature "K#
Wavelength "_#
Crystal system
Space group
C75H63Cl1Fe1O1P3Pd
0441[2
042"1#
9[60962
monoclinic
P ꢀ 10:c
C41H37B1F7O1P3Pd
0097[7
182"1#
9[60962
monoclinic
P10:c
a "_#
b "_#
c "_#
b ">#
02[609"2#
09[455"1#
14[069"5#
84[18"1#
08[076"7#
02[438"4#
19[014"7#
82[61"4#
Z
1
3
V "_2#
2529"0#
4110"3#
Dcalcd "g:cm2#
Absorption coe.cient
F"999#
0[319
0[300
9[74 min−0
0485
9[434 mm−0
1145
Crystal size "mm#
U range ">#
9[3×9[2×9[1
1[98Ð14[8
5617
5319 "Rint ꢁ 9[945#
Full!matrix L[S[ on F1
5278:9:328
0[950
9[2×9[1×9[1
3[9Ð10[8
4767
4557 "Rint ꢁ 9[010#
Full!matrix L[S[ on F1
4965:9:519
0[035
Re~ections collected
Independent re~ections
Re_nement method
Data:restrains:parameters
Goodness of _t on F1
Final R indices "I×1s"I##
R0 ꢁ 9[940 ^ wR1 ꢁ 9[986
R0 ꢁ 9[007 ^ wR1 ꢁ 9[152
Table 2[ Selected bond lengths "_# and angles "># in the crystal structure of ð"dppfcO#1PdCl1Ł = 2C5H5
Pd"0#0Cl"0#
Fe"0#0C"0#
Fe"0#0C"2#
Fe"0#0C"4#
Fe"0#0C"6#
Fe"0#0C"8#
P"0#0C"0#
P"0#0C"06#
P"1#0C"7#
P"1#0C"18#
C"0#0C"4#
C"2#0C"3#
C"5#0C"6#
C"6#0C"7#
C"8#0C"09#
1[295"0#
1[933"4#
1[959"4#
1[922"4#
1[935"4#
1[916"4#
0[793"4#
0[726"4#
0[684"4#
0[796"4#
0[335"6#
0[308"6#
0[320"6#
0[332"6#
0[307"5#
Pd"0#0P"0#
Fe"0#0C"1#
Fe"0#0C"3#
Fe"0#0C"5#
Fe"0#0C"7#
Fe"0#0C"09#
P"0#0C"00#
P"1#0O"0#
P"1#0C"12#
C"0#0C"1#
C"1#0C"2#
C"3#0C"4#
C"5#0C"09#
C"7#0C"8#
1[236"0#
1[940"4#
1[950"4#
1[958"4#
1[930"3#
1[946"4#
0[711"4#
0[376"2#
0[704"4#
0[328"5#
0[301"6#
0[315"6#
0[300"6#
0[320"5#
Cl"0#0Pd"0#0P"0#
C"0#0P"0#0C"00#
C"00#0P"0#0C"06#
C"00#0P"0#0Pd"0#
O"0#0P"1#0C"7#
C"7#0P"1#0C"18#
C"7#0P"1#0C"12#
C"1#0C"0#0C"4#
C"4#0C"0#0P"0#
C"1#0C"2#0C"3#
C"3#0C"4#0C"0#
C"5#0C"6#0C"7#
C"8#0C"7#0P"1#
C"09#0C"8#0C"7#
82[06"4#
094[7"1#
092[4"1#
095[2"1#
005[9"1#
092[8"1#
093[4"1#
096[2"3#
015[3"3#
098[3"3#
096[7"3#
096[6"3#
015[8"3#
097[9"3#
Cl"0#0Pd"0#0P"0#
C"0#0P"0#0C"06#
C"0#0P"0#0Pd"0#
C"06#0P"0#0Pd"0#
O"0#0P"1#0C"18#
O"0#0P"1#0C"12#
C"18#0P"1#0C"12#
C"1#0C"0#0P"0#
C"2#0C"1#0C"0#
C"2#0C"3#0C"4#
C"09#0C"5#0C"6#
C"8#0C"7#0C"6#
C"6#0C"7#0P"1#
C"5#0C"09#0C"8#
75[72"4#
090[1"1#
004[7"1#
011[4"1#
002[1"1#
009[7"1#
096[6"1#
015[1"3#
096[5"3#
096[6"3#
096[8"3#
096[2"3#
014[7"3#
098[0"3#

2953
R[ J[ Coyle et al[
Fig[ 0[ Molecular structure of trans!ð"dppfcO#1PdCl1Ł with adopted numbering scheme[ Hydrogen atoms are omitted for
clarity[
able that the two six!membered metallacycles appear
to be in di}erent conformations in the crystal state[
For the PdP"0#C"38\49#P"1#O"0# ring a puckered
chair conformation was established ^ the metal\
oxygen\ and both carbon atoms were coplanar within
9[900 _\ whereas P"0# and P"1# deviated from the
plane by ¦9[73 and −9[69 _\ respectively[ A dis!
torted sofa conformation was observed for the other
ring\ PdP"2#C"40\41#P"3#O"1#\ with C"40# deviating
Both tetra~uoroborates\ ð"dppeO#1PdŁ "BF3#1 and
ð"dppmO#1PdŁ "BF3#1\ are air!stable crystalline com!
pounds soluble in dichloromethane and acetone\
slightly soluble in chloroform\ but insoluble in water\
ether\ and hydrocarbon solvents[ Taking into account
the poor a.nity of the tetra~uoroborate anion for
palladium"II# ð12Ł\ it is reasonable to conclude that
an intramolecular replacement of the chloro ligands
by an oxygen of the coordinated BPMO takes place\
followed by Cl−:BF−3 ion exchange[
The structure of the cationic bis!chelate\ ð"dppe!
O#1PdŁ "BF3#1\ was established by a single crystal X!
ray di}raction study[ Selected crystallographic data
obtained\ including experimental and structure
re_nement details\ are given in Table 1[ Some molec!
ular geometry parameters are summarized in Table 3
and a general view of the dication is presented in Fig[
1[ Although crystal disorder of the BF−3 anions and
the single crystal|s insu.cient quality lowered accu!
racy of the structural results\ the cis structure of the
cation\ ð"dppeO#1PdŁ1¦\ in the solid state was estab!
lished beyond any doubt[ The Pd atom and the four
atoms constituting the _rst coordination sphere "P"0#\
P"1#\ O"0#\ and O"1## are coplanar within 9[907 _[
However\ a noticeable distortion from the ideal
by 9[66 _ from the mean plane formed by the other
_ve atoms which are coplanar within 9[95 _[ It is
worth noting the signi_cant di}erence in the
Pd0O0P
bond
angles\
013[0"5#>
for
Pd0O"0#0P"1# and 032[8"5#> for Pd0O"1#0P"3#[
Interestingly\ the Pd0O bond distances "1[977"01#
and 1[008"09# _# are either comparable with or sub!
stantially shorter than the values reported for the
Pd0O bond lengths in various palladium complexes
containing hydroxo "1[96Ð1[17 _# ð13Ł and car!
boxylato "1[01Ð1[06 _# ð14Ł ligands[ This suggests that
the Pd0O coordination bonds are of considerable
strength\ despite the fact that they are trans to phos!
phine ligand whose trans!in~uence is normally sig!
ni_cant[ The Pd0P bond distances "1[139"3# and
1[136"4# _# in the chelate are similar to those in cis!
ð"dmpmO#1PdCl1Ł "1[143"0# and 1[137"0# _# ð01Ł but
shorter by 9[97Ð9[98 _ than the Pd0P bond length
in trans!ð"dppeO#1PdCl1Ł "1[216"0# _# ð00Ł[ The
Pd0P and Pd0O bond lengths measured suggest
that the dication ð"dppeO#1PdŁ1¦ is remarkably stable[
Among other structural characteristics of the che!
late are shortened "2[16Ð2[17 _# intramolecular C= = =C
contacts due to the stacking interaction between the
almost parallel C"0#0C"5# and C"20#0C"25# phenyl
square!planar con_guration is observed in the crystal rings[ Also\ strong distortions are observed in the
structure\ the O0Pd0O and P0Pd0P bond angles tetrahedral environment of P"0# and P"2#\ due to steric
being 73[3"3#> and 86[2"1#>\ respectively[ It is remark! hindrance[ Thus\ Pd0P"0#0C"0# and Pd0P"2#0

Palladium"II# complexes of hybrid phosphine
2954
Table 3[ Selected bond lengths "_# and angles "># in the crystal structure of ð"dppeO#1PdŁ "BF−3 #1
Pd0O"1#
Pd0P"2#
1[977"01#
1[139"3#
0[68"1#
0[75"1#
0[66"1#
0[72"1#
0[70"1#
0[426"01#
0[79"1#
0[42"1#
Pd0O"0#
Pd0P"0#
1[008"09#
1[136"4#
0[68"1#
0[498"00#
0[68"1#
0[79"1#
0[75"1#
0[66"1#
0[70"1#
0[44"2#
P"0#0C"6#
P"0#0C"38#
P"1#0C"49#
P"1#0C"08#
P"2#0C"14#
P"3#0O"1#
P"3#0C"32#
C"38#0C"49#
P"0#0C"0#
P"1#0O"0#
P"1#0C"02#
P"2#0C"40#
P"2#0C"20#
P"3#0C"26#
P"3#0C"41#
C"40#0C"41#
O"1#0Pd0O"0#
O"0#0Pd0P"2#
O"0#0Pd0P"0#
73[3"3#
062[0"2#
78[5"2#
O"1#0Pd0P"2#
O"1#0Pd0P"0#
P"2#0Pd0P"0#
77[7"2#
062[7"2#
86[2"1#
C"6#0P"0#0C"0#
C"0#0P"0#0C"38#
C"0#0P"0#0Pd
098[0"7#
87[0"7#
C"6#0P"0#0C"38#
C"6#0P"0#0Pd
094[6"7#
097[8"5#
009[8"5#
009[5"6#
098[2"6#
096[0"7#
092[4"8#
098[5"5#
019[0"6#
097[9"6#
000[5"7#
000[1"7#
032[8"5#
001[8"01#
001[5"02#
011[6"5#
001[0"6#
097[1"8#
098[3"8#
094[8"8#
095[1"8#
009[4"5#
009[1"7#
096[6"7#
097[1"7#
013[0"5#
007[0"01#
007[9"02#
C"38#0P"0#0Pd
O"0#0P"1#0C"02#
O"0#0P"1#0C"08#
C"02#0P"1#0C"08#
C"40#0P"2#0C"20#
C"40#0P"2#0Pd
C"20#0P"2#0Pd
O"1#0P"3#0C"32#
O"1#0P"3#0C"41#
C"32#0P"3#0C"41#
P"3#0O"1#0Pd
O"0#0P"1#0C"49#
C"49#0P"1#0C"02#
C"49#0P"1#0C"08#
C"40#0P"2#0C"14#
C"14#0P"2#0C"20#
C"14#0P"2#0Pd
O"1#0P"3#0C"26#
C"26#0P"3#0C"32#
C"26#0P"3#0C"41#
P"1#0O"0#0Pd
C"49#0C"38#0P"0#
C"41#0C"40#0P"2#
C"38#0C"49#0P"1#
C"40#0C"41#0P"3#
C"20# bond angles are increased to 011[6"5# and
019[0"6# degrees\ whereas adjacent C"0#0P"0#0
C"38# and C"14#0P"2#0C"20# bond angles are
diminished to 87[0"7# and 092[4"7# degrees\ respec!
tively[ On the contrary\ P"1# and P"3# of the phos!
phoryl groups form tetrahedral bond angles of the
almost ideal value\ varying in the range of 096[0"7# to
001[0"6#>[
According to the room temperature 20P NMR data\
the ð"dppeO#1PdŁ "BF3#1 remains cis in dichloro!
methane or methanol solutions\ with both chelate
rings undergoing conformational changes which are
fast on the NMR time scale[ Two sharp doublets of
doublets at 25[4 and 37[1 ppm with JPÐP ꢁ 09 and
2 Hz were observed in the 20P NMR spectrum of
ð"dppeO#1PdŁ1¦ in aqueous methanol\ indicating that
the geometry around the metal center is cis[
The dpppO counterpart of ð"dppeO#1PdŁ1¦ and
ð"dppmO#1PdŁ1¦ was prepared by the reaction
between ð"dpppO#1PdCl1Ł and AgNO2 in dichloro!
methane:water\ followed by the treatment of the reac!
tion mixture with 39) NaBF3 in water[ Two
broadened singlet resonances were observed in the
20P NMR spectrum of the organic phase\ with the
chemical shifts of 29 "Dn0:1 ꢁ 39 Hz# and 44
"Dn0:1 ꢁ 099 Hz# ppm being indicative of a P\O!coor!
dination mode for the dpppO ligands\ as expected[
Fig[ 1[ Molecular structure of cis!ð"dppeO#1PdŁ1¦ with
adopted numbering scheme for the metallacycle atoms[
Hydrogen atoms are omitted for clarity[

2955
R[ J[ Coyle et al[
However\ once precipitated by adding ether to the 0091Ð0018 cm−0 due to the coordinated phosphoryl
organic layer of the reaction mixture\ the oxygens and no peaks in the range of 0079Ð0199 cm−0
ð"dpppO#1PdŁ "BF3#1 appeared to be very poorly sol! where {{free|| phosphoryl P1O bonds normally
uble in common organic solvents\ dichloromethane absorb ð5\03\04Ł[ At the same time\ two groups of
and acetone included[ In spite of this remarkably low bands were observed in the IR spectrum of the solid
solubility of the isolated crystalline compound\ its 20
P
ð"dpppO#1PdŁ "BF3#1\ at 0012Ð0094 cm−0 and 0084Ð
NMR spectrum in CH1Cl1 was measured\ exhibiting 0064 cm−0[ The former was obviously due to PO
two sharp doublets "JPÐP ꢁ 6 Hz# with virtually the groups coordinated with the metal\ whereas the latter
same chemical shifts "29[3 and 44[5 ppm# as those pointed to the presence of free phosphoryls in the
observed before the complex was isolated[ It is con! sample[ It is clear that in order to contain both types of
ceivable that in the concentrated solution formed the phosphoryl groups while retaining square!planar
upon reacting ð"dpppO#1PdCl1Ł with Ag¦ and then geometry at the Pd centers\ the solid ð"dpppO#1PdŁ
BF−3 \ the structure of the species obtained is somewhat "BF3#1 must possess polymeric or macrocyclic struc!
di}erent from that of the complex which has been ture and should rather be formulated as
isolated and consequently redissolved[ The identical "ð"dpppO#1PdŁ "BF3#1#n[ This is consistent with the
20P NMR chemical shifts suggest that both the P and 20P NMR data obtained for the concentrated solution
O centers participate in coordinative interactions with of oligomeric ð"dpppO#1PdŁ "BF3#1\ prepared upon
the metal ð5\03Ł[ On the other hand\ intermolecular the exhaustive dechlorination of the ð"dpppO#1PdCl1Ł
Pd0O interactions of the type Pd0P0CH1 with Ag¦ "see above#[ The remarkable di}erence in
0CH10CH10PO0Pd might be pictured for the the structure and behaviour of the three cationic com!
concentrated solution of the complex\ resulting in the plexes is de_nitely due to the substantial decrease in
formation of oligometric:polymeric chains "Fig[ 2#[ the magnitude of the chelate e}ect when going from
Facile ligand exchange in the oligomer is likely to be the 4! and 5!membered metallacyles "ð"dppmO#1PdŁ1¦
responsible for the line broadening in the 20P NMR and ð"dppeO#1PdŁ1¦\ respectively# to the analogous\
spectrum of the concentrated solution[ It is note! but much less stable\ 6!membered rings
worthy that the PO0Pd resonance was noticeably "ð"dpppO#1PdŁ1¦ ð15Ł[ For the same reason\ the
broader than the P0Pd signal\ suggesting that the {{silverless|| synthesis of ð"dpppO#1PdŁ "BF3#1 from the
exchange processes involving the oxygen centers may corresponding dichloride requires many more ion!
be faster than those resulting in the cleavage and for! exchange extractions with aqueous NaBF3\ as com!
mation of the P0Pd bonds[ In contrast\ dilute solu! pared with the above described similar preparation of
tions of the isolated complex contain the monomeric ð"dppmO#1PdŁ "BF3#1 and ð"dppeO#1PdŁ "BF3#1[ For
cation\ ð"dpppO#1PdŁ1¦\ as indicated by the 20P NMR instance\ after
data "see above#[ ð"dpppO#1PdCl1Ł had been thoroughly washed with
a dichloromethane solution of
Clearly\ intramolecular vs intermolecular O0Pd 39) aqueous NaBF3 01 times\ the conversion to
coordination modes in the ð"dpppO#1PdŁ1¦ system are ð"dpppO#1PdŁ "BF3#1 was still incomplete "20P NMR#[
strongly in~uenced by concentration e}ects which
Attempted syntheses of ð"dppfcO#1PdŁ1¦ and
were not observed for the ð"dppmO#1PdŁ1¦ and ð"dppbO#1PdŁ1¦ from the corresponding dichloro
ð"dppeO#1Ł1¦ complexes[ Furthermore\ in the solid complexes and aqueous NaBF3 or AgNO2:NaBF3
state both ð"dppmO#1PdŁ1¦ and ð"dppeO#1PdŁ1¦ are were unsuccessful\ and a complex mixture of unidenti!
monomeric chelates\ according to the solubility\ X! _ed products was obtained in both cases "20P NMR#[
ray\ and also IR data[ The IR spectra "KBr# of their The metallacycles formed by the dppbO and dppfcO
tetra~uoroborate salts exhibited strong bands at ligands are apparently too large in size to be
Fig[ 2[ Proposed structure for the "ð"dpppO#1PdŁ1¦#n oligomer containing both coordinated and free phosphoryl groups[

Palladium"II# complexes of hybrid phosphine
2956
su.ciently stable for successful isolation and charac! ð"dpppO#1PdCl1Ł
terization of the corresponding Pd chelates[ Most
likely\ the generated compounds exist as mixtures of
oligomeric species[
A solution of Na1ðPdCl3Ł obtained by dissolving
PdCl1 "419 mg ^ 1[83 mmol# and NaCl "274 mg ^ 5[53
mmol# in hot methanol "39 ml# was added dropwise
to a vigorously stirred solution of dpppO "1[668 g ^
5[38 mmol# in CH1Cl1 "29 ml#[ The mixture was taken
to dryness "rotary evaporation# and the residue was
extracted with CH1Cl1 "199 ml ^ the complex is only
moderately soluble in dichloromethane ð17Ł#[ The
combined dichloromethane extracts were _ltered\
reduced in volume\ and treated with ether to give
a yellow microcrystalline solid which was separated\
washed with ether\ and dried under vacuum[ The yield
of ð"dpppO#1PdCl1Ł = H1O was 2[946 g "87)#[ Anal ]
Calcd for C43H43Cl1O2P3Pd"C43H41Cl1O1P3Pd = H1O# ]
EXPERIMENTAL
NMR spectra were recorded on a Varian VXR!199
spectrometer[ Chemical shifts are reported relative to
TMS "0H# and 74) H2PO3 "20P#[ The BPMO ligands
may be synthesized by the procedures reported in the
literature ð0b\2\5\16Ł[ The phosphorus ligands\
dppmO\ dppeO\ dpppO\ dppbO\ and dppfcO used in
this work were prepared by the selective catalytic
mono!oxidation of the corresponding bis!phosphines
ð07Ł[ All other chemicals were purchased from Organ!
ometallics\ Aldrich\ and Strem and used as received[
The synthesis\ isolation\ and puri_cation of all com!
plexes were conducted in air[
0
C\ 50[5 ^ H\ 4[1[ Found ] C\ 50[6 ^ H\ 3[8[ H NMR
"CDCl2#\ d ] 0[7 "m\ 3H\ CCH1C# ^ 1[3 "m\ 3H\
CH1PPd# ^ 1[5 "m\ 3H\ CH1PO# ^ 6[9Ð6[7 "m\ 39H\
C5H4#[
ð"dppbO#1PdCl1Ł
ð"dppmO#1PdCl1Ł
A solution obtained by dissolving PdCl1 "102 mg ^
0[19 mmol# and NaCl "029 mg ^ 1[13 mmol# in hot
methanol "49 ml# was added dropwise to a vigorously
stirred solution of dppbO "0[105 g ^ 1[64 mmol# in
CH1Cl1 "29 ml# ð17Ł[ Evaporation of the mixture gave
a yellow oil which was dissolved in CH1Cl1 and the
resulting solution was _ltered\ reduced in volume to
ca 4 ml\ and treated with ether "19 ml# to precipitate
the complex[ The crude solid product thus obtained
"contaminated with ca 4) dppbO ^ 20P NMR# was
dissolved in dichloromethane "09 ml#\ the mixture was
diluted with benzene "ca 29 ml#\ and the resulting
yellow solution was slowly reduced in volume to
ca 09 ml "rotary evaporation at room temperature#[
Upon standing for a few hours\ yellow crystals of
A solution of Na1ðPdCl3Ł obtained by dissolving
PdCl1 "154 mg ^ 0[49 mmol# and NaCl "079 mg ^ 2[09
mmol# in hot methanol "19 ml# was added dropwise
to a vigorously stirred solution of dppmO "0[348 g ^
2[54 mmol# in CH1Cl1 "19 ml#[ The mixture was taken
to dryness "rotary evaporation# and the residue was
extracted with CH1Cl1 "29 ml#[ The dichloromethane
solution was _ltered\ reduced in volume to ca 04 ml\
diluted with ether "portionwise\ 3×04 ml#\ and left at
−04>C overnight[ The yellow precipitate was separ!
ated\ washed with ether\ and dried under vacuum[ The
yield of ð"dppmO#1PdCl1Ł was 0[359 g "88)#[ The
20P and 0H NMR spectra of this complex in both
chloroform!d and methanol!d3 are described in the
analytically
and
spectroscopically
pure
0
text and Table 0[ In the H NMR spectra\ aromatic
ð"dppbO#1PdCl1Ł = 1C5H5 precipitated\ which was sep!
arated\ washed with small quantities of benzene\ and
dried[ The yield was 0[332 g "87)#[ Anal ] Calcd for
C57H57Cl1O1P3Pd "C45H45Cl1O1P3Pd = 1C5H5# ] C\
56[9 ^ H\ 4[5[ Found ] C\ 56[3 ^ H\ 4[6[ 0H NMR
"CDCl2#\ d ] 0[5 "m\ 7H\ C"CH1#1C# ^ 1[1 "m\ 3H\
CH1PPd# ^ 1[3 "m\ 3H\ CH1PO# ^ 6[0Ð6[7 "m\
39H¦01H\ C5H4¦C5H5# ^ an intense singlet at 6[2
ppm was observed due to the benzene present in the
solid[
protons of the complex resonate as multiplets at 5[8Ð
7[9 ppm and 6[907[9 ppm in CDCl2 and CD2OD\
respectively[
ð"dppeO#1PdCl1Ł
A solution of Na1ðPdCl3Ł obtained by dissolving
PdCl1 "387 mg ^ 1[70 mmol# and NaCl "250 mg ^ 5[11
mmol# in warm methanol "49 ml# was added dropwise
to a vigorously stirred solution of dppeO "1[503 g ^ trans!ð"dppfcO#1PdCl1Ł
5[12 mmol# in CH1Cl1 "29 ml#[ The mixture was evap!
orated to dryness and the residue was extracted with
A mixture of PdCl1 "196 mg ^ 0[06 mmol# and NaCl
CH1Cl1[ The combined dichloromethane extracts were "028 mg ^ 1[28 mmol# was stirred with methanol "39
_ltered\ reduced in volume\ and treated with ether[ ml# at ca 49>C until the solids dissolved[ The resulting
The yellow precipitate was separated\ washed with brown solution of Na1ðPdCl3Ł was added dropwise to
ether\ and dried under vacuum[ The yield of ð"dppe! a stirring solution of dppfoO ð07\08Ł "0[366 g ^ 1[5
0
O#1PdCl1Ł was 1[566 g "84)#[ H NMR "CDCl2#\ d ] mmol# in CH1Cl1 "19 ml#[ After the dark red mixture
1[5 "m\ 7H\ CH1# ^ 6[9Ð6[8 "m\ 39H\ C5H4#[
was evaporated to dryness the residue was extracted

2957
R[ J[ Coyle et al[
with CH1Cl1 "_rst 19 ml\ then 3×4 ml#\ and the com! of ð"dpppO#1PdCl1Ł "0[99 g ^ 9[86 mmol# in CH1Cl1
bined extracts were _ltered\ reduced in volume to ca "7 ml#\ causing an immediate precipitation of AgCl[
09 ml\ and diluted with ether "portionwise\ 3×4 ml#[ Water "4 ml# and CH1Cl1 "6 ml# were added\ and the
The orange!red crystals were separated\ washed with mixture was stirred for another 4 min[ The organic
ether\ and dried[ The yield of the trans!ð"dppfcO#1 phase was separated\ and the aqueous suspension of
PdCl1Ł = CH1Cl1 was 0[433 g "83)#[ Anal ] Calcd for AgCl was washed with CH1Cl1 several times[ The com!
C58H47Cl3Fe1O1P3Pd "C57H45Cl1Fe1O1P3Pd =CH1Cl1# ] bined dichloromethane solutions were vigorously
0
C\ 48[0 ^ H\ 3[1[ Found ] C\ 48[5 ^ H\ 3[1[ H NMR stirred with 39) NaBF3 "1×19 ml\ 29 min each#\
"CDCl2#\ d ] 3[2 "s\ 1H\ C4H3# ^ 3[3 "s\ 1H\ C4H3# ^ 3[5 separated\ _ltered\ reduced in volume\ and treated
"s\ 1H\ C4H3# ^ 3[8 "s\ 1H\ C4H3# ^ 6[1Ð6[7 "m\ 39H\ with ether[ The light!yellow precipitate was washed
C5H4#[
with ether and dried under vacuum[ The yield of the
cationic complex was 9[73 g "65)#[ Anal ] Calcd for
C43H41B1F7O1P3Pd ] C\ 46[9 ^ H\ 3[5[ Found ] C\ 45[4 ^
cis!ð"dppmO#1PdŁ "BF3#1
0
H\ 3[5[ H NMR "acetone!d5#\ d ] 1[7 "m\ 3H\ CH1# ^
2[9 "m\ 3H\ CH1# ^ 2[1 "m\ 3H\ CH1# ^ 6[0Ð6[8 "m\ 39H\
C5H4#[ 20P NMR "CH1Cl1#\ d ] 29[3 "d\ 1P\ JPÐP ꢁ 6[9
Hz\ PPd# ^ 44[5 "d\ 1P\ JPÐP ꢁ 6[9 Hz\ POPd#[ IR
"KBr#\ cm−0 ] 0084\ 0077\ 0064\ 0012\ 0094 "PO#[
A solution of ð"dppmO#1PdCl1Ł "191 mg ^ 9[10
mmol# in CH1Cl1 "4 ml# was vigorously stirred with
39) aqueous NaBF3 "09 ml# for 04 min[ The aqueous
layer was separated by a pipette\ another 09 ml of
39) NaBF3 were added to the dichloromethane solu!
tion\ and the mixture was stirred for another 04 min[
This procedure was repeated _ve times[ The organic
phase was separated\ _ltered through cotton\ and
evaporated[ The solid residue was recrystallized twice
from CH1Cl1:ether to give 055 mg "63)# of white cis!
ð"dppmO#1PdŁ "BF3# = H1O[ Anal ] Calcd for
C49H35B1F7O2P3Pd "C49H33B1F7O1P3Pd = H1O# ] C\
43[6 ^ H\ 3[1[ Found ] C\ 43[8 ^ H\ 3[1[ 0H NMR "ace!
tone!d5#\ d ] 3[7 "dd\ 3H\ JPÐH ꢁ 8[7 and 02[7 Hz\ CH1# ^
6[1Ð7[9 "m\ 39H\ C5H4#[ 20P NMR "acetone!d5#\ d ]
25[1 "d\ 1P\ JPÐP ꢁ 4[2 Hz\ PPd# ^ 48[6 "d\ 1P\ JPÐ
P ꢁ 4[2 Hz\ POPd#[ IR "KBr#\ cm−0 ] 0018\ 0091 "PO#[
X!ray diffraction studies
X!ray di}raction data were obtained with a Siemens
P2:PC four!circle di}ractometer with MoÐKa!radi!
ation and a graphite monochromator "u:1u scan
method# at 042 K and room temperature for single
crystals of trans!ð"dppfcO#1PdCl1Ł and cis!ð"dppeO#1
PdŁ "BF3#1\ respectively[ The di}raction quality of all
examined crystal samples of the cationic complex was
rather poor\ displaying broad re~ection peaks and
irregular twinning[ As all attempts to cool the samples
led to an increase in the di}raction pro_les\ data col!
lection was performed at room temperature[ An
empirical absorption correction was applied for the
trans!ð"dppfcO#1PdCl1Ł\ but not for the ð"dppeO#1PdŁ
"BF3#1 because of insu.cient di}raction data quality[
The structures were solved by direct methods and
re_ned by the least squares techniques in the aniso!
tropic "isotropic for disordered BF−3 anions# approxi!
mation[ All H atoms were placed in geometrically
calculated positions and included into re_nement
using a riding motion model[ A PC SHELX PLUS
program package was used for all calculations[
Rotational disorder of the BF−3 anions was detected
in the di}erence Fourier maps for the cationic chelate\
and therefore additional orientations of these anions
were taken into account in the _nal re_nement[
cis!ð"dppeO#1PdŁ "BF3#1
A solution of ð"dppeO#1PdCl1Ł "193 mg ^ 9[10 mmol#
in CH1Cl1 "4 ml# was vigorously stirred with 39)
aqueous NaBF3 "09 ml# for 04 min[ The aqueous layer
was separated by a pipette\ another 09 ml of 39)
NaBF3\ were added to the dichloromethane solution\
and the mixture was stirred for another 04 min[ This
procedure was repeated _ve times[ The organic phase
was separated\ _ltered through cotton\ and evap!
orated[ The solid residue was recrystallized from
CH1Cl1:ether "twice# and dried under vacuum to give
104 mg "85)# of pale!yellow cis!ð"dppeO#1PdŁ "BF3#1[
Anal ] Calcd for C41H37B1F7O1P3Pd ] C\ 45[2 ^ H\ 3[3[
Found ] C\ 45[0 ^ H\ 3[2[ 0H NMR "acetone!d5#\ d ] 2[1
"m\ 7H\ CH1# ^ 6[1Ð7[1 "m\ 39H\ C5H4#[ 20P NMR
"MeOH#\ d ] 25[4 "dd\ 1P\ JPÐP ꢁ 09[9 Hz and 2[9 Hz\
PPd# ^ 37[1 "dd\ 1P\ JPÐP ꢁ 09[9 Hz and 2[9 Hz\ POPd#[
20P NMR "acetone!d5#\ d ] 26[7 "dd\ 1P\ JPÐP ꢁ 7[4 Hz
and 3[5 Hz\ PPd# ^ 36[8 "dd\ 1P\ JPÐP ꢁ 7[4 H and 3[5
Hz\ POPd#[ IR "KBr#\ cm−0 ] 0014\ 0092 "PO#[
Acknowled`ement*DuPont and the Science and Technology
Endowment Program "STEP# Council at Wilfrid Laurier
University are gratefully acknowledged for support[
Supportin` information available*Full details of the X!ray
di}raction studies of trans!ð"dppfcO#1PdCl1Ł and cis!ð"dppe!
O#1PdŁ "BF3#1\ including crystallographic data\ data collec!
tion\ structure solution and re_nement\ ORTEP drawings\
full tables of non!hydrogen atom coordinates with isotropic
displacement parameters\ full tables of bond lengths and
bond angles\ hydrogen atom coordinates\ tables of aniso!
tropic displacement parameters "11 pages#\ and two X!ray
structure _les in the CIF format[ Ordering information is
ð"dpppO#1PdŁ "BF3#1
A solution of AgNO2 "9[32 g ^ 1[4 mmol# in water
"1 ml# was added to a vigorously stirred suspension given on any current masthead page[

Palladium"II# complexes of hybrid phosphine
2958
REFERENCES
62[1 "s\ C4H3# ^ 62[2 "d\ JPÐC ꢁ 0[6 Hz\ C4H3# ^ 62[4
"d\ JPÐC ꢁ 0[6 Hz\ C4H3# ^ 017[1 "d\ JPÐC ꢁ 00[9
Hz\ m!C5H4PCp# ^ 017[3 "d\ JPÐC ꢁ 05[6 Hz\ m!
C5H4P"O#Cp# ^ 020[2 "s\ p!C5H4PCp# ^ 020[3 "s\ p!
C5H4P"O#Cp# ^ 020[3 "d\ JPÐC ꢁ 8[6 Hz\ o!
C5H4PCp# ^ 022[3 "d\ JPÐC ꢁ 08[6 Hz\ o!
C5H4P"O#Cp# ^ 023[4 "d\ JPÐC ꢁ 094[5 Hz\ q!
C5H4PCp# ^ 027[7 "d\ JPÐC ꢁ 09[7 Hz\ q!
C5H4P"O#Cp#[ 20P NMR "CDCl2\ 19>C#\ d ]
−05[6 "s\ 0P\ CpPPh1# ^ 17[4 "s\ 0P\ CpP"O#Ph1#[
Anal ] Calcd for C57H47Fe1O2P3 "C23H17FeO!
P1 = 9[4H1O# ] C\ 69[4 ^ H\ 4[9[ Found ] C\ 69[6 ^ H\
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4[9 ^ "b# Although dppfcO itself is
a new
compound\ its rhenium ð08cŁ and tungsten ð08dŁ
complexes have been reported and structurally
characterized[ The Re and W complexes were
obtained by the oxidation of the corresponding
dppfc metal derivatives with H1O1 ^ "c# Hor\ T[ S[
A[\ Chan\ H[ S[ O[\ Tan\ K[!L[\ Phang\ L[!T[\
Yan\ Y[ K[\ Liu\ L[!K[ and Wen\ L[!K[\ Poly!
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11[ Bertseh!Frank\ B[ and Frank\ W[\ Acta Crys!
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gold\ A[ L[\ Wu\ G[ and Heck\ R[ F[\ Inor`[ Chim[
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Grushin\ V[ V[ and Alper\ H[\ Or`anometallics\
0886\ 05\ 86[
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00\ 1101 ^ "c# Grushin\ V[ V[\ 0884\ unpublished
results[
07[ Prepared by the recently developed\ novel cata!
lytic method for the synthesis of BPMOs ]
Grushin\ V[ V[\ unpublished results "0884Ð0885# ^
Patent application has been _led[
Torregrosa\ J[\ Garcia\ G[\ Lopez\ G[\ Chaloner\
ꢂ
P[ A[\ Hitchcock\ P[ B[ and Harrison\ R[ M[\
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New York\ 0877[
08[ "a# Spectral and analytical data for dppfcO ]
NMR "CDCl2\ 19>C#\ d ] 3[9 "m\ 1H\ Cp# ^ 3[1 "m\
1H\ Cp# ^ 3[3 "m\ 1H\ Cp# ^ 3[5 "m\ 1H\ Cp# ^ 6[0Ð
6[6 "m\ 19H\ Ph#[ 02C NMR "CDCl2\ 19>C#\ d ] 16[ "a# Seyferth\ D[\ US Patent 2\315\910\ 0858 ^ "b#
61[8 "s\ C4H3# ^ 62[9 "s\ C4H3# ^ 62[0 "s\ C4H3# ^
Abatjoglou\ A[ G[ and Kapicak\ L[ A[\ US Patent

2969
R[ J[ Coyle et al[
3\318\050\ 0873[ "c# Bondarenko\ N[ A[\ Rudo! 17[ It is worth noting that the solubility of dpppO in
mino\ M[ V[ and Tsvetkov\ E[ N[\ Izv[ Akad[ Nauk
SSSR\ Ser[ Khim[\ 0889\ 1079 ^ Synthesis 0880\
014 ^ "d# Brock\ S[ L[ and Mayer\ J[ M[\ Inor`[
Chem[\ 0880\ 29\ 1027[
CH1Cl1 and CHCl2 is much higher than that of
dppbO\ whereas the solubility of ð"dpppO#1PdCl1Ł
in these solvents is noticeably lower than that of
ð"dppbO#1PdCl1Ł[