The preparation and characterisation of a series of cationic bimetallic linear triphos-bridged complexes.

Article abstract of DOI:10.1016/S0277-5387(98)00346-5

Equimolar quantities of [Mo(CO)(η²-RC₂R′)₂Cp][BF₄] (R = R′ = Me,Ph; R = Me, R′ = Ph) and L,L′ or L″ {L,L′ or L″ = [WI₂ (CO){PhP(CH₂CH₂PPh₂) ₂-P,P′}(η²-RC₂R′)]} (L,R = R′ = Me; L′,R = R′ = Ph; L″,R = Me, R′ = Ph) react in CH₂Cl₂ at room temperature to give the new bimetallic complexes, [Mo(CO)(L,L′ or L″-P)(η²-RC₂R′)Cp][BF₄] (1-9) via displacement of the alkyne ligand on the molybdenum centre. The complexes have been characterised by elemental analysis, IR and ¹H NMR spectroscopy, and in selected cases by ³¹P NMR spectroscopy.

Full text of DOI:10.1016/S0277-5387(98)00346-5

\
PERGAMON
Polyhedron 07 "0888# 618Ð622
The preparation and characterisation of a series of cationic
bimetallic linear triphos!bridged complexes of the type
ðMo"CO#"L\L? or LýÐP#"h1!RC1R?#CpŁðBF3Ł
"L\L? or LýꢀðWI1"CO#"PhP"CH1CH1PPh1#1ÐP\P?#"h1!RC1R?#Ł
"L\RꢀR?ꢀMe^ L?\RꢀR?ꢀPh^ Lý\RꢀMe\R?ꢀPh#
Paul K[ Bakerꢁ\ David E[ Belcher
Department of Chemistry\ University of Wales\ Bangor\ Gwynedd LL46 1UW\ U[K[
Received 2 July 0887^ accepted 10 September 0887
Abstract
Equimolar quantities of ðMo"CO#"h1!RC1R?#1CpŁðBF3Ł "RꢀR?ꢀMe\Ph^ RꢀMe\ R?ꢀPh# and L\L? or Lý "L\L? or LýꢀðWI1
"CO#"PhP"CH1CH1PPh1#1!P\P?#"h1!RC1R?#Ł# "L\RꢀR?ꢀMe^ L?\RꢀR?ꢀPh^ Lý\RꢀMe\ R?ꢀPh# react in CH1Cl1 at room tem!
perature to give the new bimetallic complexes\ ðMo"CO#"L\L? or LýÐP#"h1!RC1R?#CpŁðBF3Ł "0Ð8# via displacement of the alkyne
ligand on the molybdenum centre[ The complexes have been characterised by elemental analysis\ IR and 0H NMR spectroscopy\
and in selected cases by 20 P NMR spectroscopy[ Þ 0888 Elsevier Science Ltd[ All rights reserved[
Keywords] Bimetallic * linear triphos!bridged^ Molybdenum"II#^ Tungsten"II#^ Alkyne complex^ Cyclopentadienyl
0[ Introduction
molybdenum complexes ðMo"CO#"h1!RC1R?#1CpŁðBF3Ł
"RꢀR?ꢀMe\Ph^ RꢀMe\ R?ꢀPh# to a}ord the bimet!
allic linear!triphos!bridged complexes ðMo"CO#"L\L? or
LýÐP?#"h1!RC1R?# CpŁðBF3Ł[
Over the years\ bimetallic\ bidentate phosphine!
bridged transition!metal complexes have been extensively
investigated ð0Ð03Ł\ whereas potentially tridentate phos!
phine!bridged multimetallic complexes have received
much less attention[ In 0851\ Hewertson and Watson
ð04Ł\ described the _rst synthesis of linear triphos\
PhP"CH1CH1PPh1#1\ and more recently King and
Kapoor ð05Ł developed an improved synthesis of linear
triphos[ An example\ of the use of this ligand to prepare
trimetallic\ linear!triphos bridged complexes is\ ð"M"CO#4#2
"m2!PhP"CH1CH1PPh1#1ÐP\P?\Pý#Ł "MꢀCr\Mo# which
have been described by Horng et al[ in 0883 ð06Ł[
In 0885 ð07Ł\ we described the synthesis and crystallo!
graphic characterisation "RꢀR?ꢀMe^ RꢀMe\ R?ꢀPh#
of the bidentately!coordinated linear triphos complexes\
ðWI1"CO#"PhP"CH1CH1PPh1#1ÐP\P?#"h1!RC1R?#Ł "Rꢀ
R?ꢀMe\Ph^ RꢀMe\ R?ꢀPh#[ In this paper we describe
the reactions of ðWI1"CO#"PhP"CH1CH1PPh1#1ÐP\P?#
"h1!RC1R?#Ł "RꢀR?ꢀMe\Ph^ RꢀMe\ R?ꢀPh# as
monodentate phosphines "L\L? or Lý# with the cationic
1[ Experimental
All reactions were carried out under a nitrogen atmo!
sphere according to standard vacuum:Schlenk line pro!
cedures[ All chemicals were obtained commercially^
diethyl ether and dichloromethane were dried\ distilled
and purged with nitrogen before use[
Elemental analyses were determined using a Carlo
Erba Elemental Analyser MOD 0097 "using helium as a
carrier gas#[ IR spectra were recorded as CH1Cl1 _lms
between NaCl plates on a Perkin!Elmer 0599 Series FTIR
spectrophotometer[ 0H and 20 P NMR spectra were rec!
orded on a Bruker AC149 MHz instrument at room tem!
perature\ referenced to SiMe3 for 0H and to 74) H2PO3
for 20 P NMR spectra[
The starting materials ðWI1"CO#"PhP"CH1CH1PPh1#1Ð
P\P?#"h1!RC1R?#Ł "RꢀR?ꢀMe\Ph^ RꢀMe\ R?ꢀPh#
were prepared in accordance with the published method
ð07Ł[ The method described by Bottrill and Green ð08Ł
ꢁ Corresponding author[ Fax] ¦33!01!3726!947[
9166!4276:88:, ! see front matter Þ 0888 Elsevier Science Ltd[ All rights reserved[
PII] S9166!4276 "87#99235!4

629
P[K[ Baker\ D[E[ Belcher:Polyhedron 07 "0888# 618Ð622
Table 0
Physical and analytical dataa for the bimetallic complexes ðMo"CO#"L\L? or LýÐP#"h1!RC1R?#CpŁðBF3Ł "0Ð8#
Complex
Yield ")#
Colour
C ")# "calcd[#
H ")# "calcd[#
0
1
2
3
4
5
6
7
8
ðMo"CO#"LÐP#"h1!MeC1Me#CpŁðBF3Ł
ðMo"CO#"LÐP#"h1!MeC1Ph#CpŁðBF3Ł
ðMo"CO#"LÐP#"h1!PhC1Ph#CpŁðBF3Ł
ðMo"CO#"L?ÐP#"h1!MeC1Me#CpŁðBF3Ł
ðMo"CO#"L?ÐP#"h1!MeC1Ph#CpŁðBF3Ł
ðMo"CO#"L?ÐP#"h1!PhC1Ph#CpŁðBF3Ł
ðMo"CO#"LýÐP#"h1!MeC1Me#CpŁðBF3Ł
ðMo"CO#"LýÐP#"h1!MeC1Ph#CpŁðBF3Ł
ðMo"CO#"LýÐP#"h1!PhC1Ph#CpŁðBF3Ł
41
20
20
59
47
32
39
24
12
pale violet
very pale violet
dull\ pale green
green
dull green
green
dull green
dull\ pale green
dull\ pale green
30[6 "31[9#
33[3 "33[2#
34[1 "35[3#
35[1 "34[5#
37[6 "38[9#
49[9 "49[3#
33[5 "33[7#
36[9 "36[9#
37[7 "49[9#
2[7 "2[5#
2[7 "2[5#
2[6 "2[3#
2[6 "2[5#
2[5 "2[5#
2[7 "2[5#
2[7 "2[5#
2[7 "2[5#
2[8 "2[5#
aCalculated values in parentheses] LꢀðWI1"CO#"PhP"CH1CH1PPh1#1!P\P?#"h1!MeC1Me#Ł\ L?ꢀðWI1"CO#"PhP"CH1CH1PPh1#1!P\P?#"h1!
PhC1Ph#Ł\ LýꢀðWI1"CO#"PhP"CH1CH1PPh1#1!P\P?#"h1!MeC1Ph#Ł[
was used to prepare the complexes ðMo"CO#"h1!
Table 1
Infrared dataa for the bimetallic complexes ðMo"CO#"L\L? or Lý!P#"h1!
RC1R?#CpŁðBF3Ł "0Ð8#
RC1R?#1CpŁðBF3Ł "RꢀR?ꢀMe\Ph^ RꢀMe\ R?ꢀPh#[
1[0[ Preparations ðMo"CO#"LÐP?#"h1!MeC1Me#CpŁ
Complex
n"C0O# "cm−0
#
n"C0C# "cm−0
#
ðBF3Ł
"LꢀðWI1"CO#"PhP"CH1CH1PPh1#1ÐP\P?#
"h1!MeC1Me#Ł# "0#
0
1
2
3
4
5
6
7
8
0853 "s\ br#
0857 "s\ br#
0850 "s\ br#
0858 "s\ br#
0857 "s\ br#
0879 "s\ br#
0869 "s\ br#
0863 "s\ br#
0865 "s\ br#
0541"br\ w#
0546 "br\ w#
0543 "br\ w#
0575 "br\ w#
0543 "br\ w#
0542 "br\ w#
0549 "br\ w#
0547 "br\ w#
0559 "br\ w#
To a stirred solution of ðMo"CO#"h1!MeC1Me#1CpŁ
ðBF3Ł "9[29 g\ 9[670 mmol# was added ðWI1"CO#"PhP
"CH1CH1PPh1#1ÐP\P?#"h1!MeC1Me#Ł
"9[71 g\
9[670
mmol# in 14 cm2 of CH1Cl1 under a nitrogen atmosphere
for 1 h at room temperature and stirred continuously[
The reaction mixture was then _ltered through celite and
09 cm2 of dried\ distilled and degassed Et1O was added
to precipitate the bimetallic product[ The liquid portion
was syringed o} and another 09 cm2 measure of Et1O
added to wash the product[ This washing procedure was
carried out until the liquid portion became colourless[
All residual solvent was then removed in vacuo to give
the pale violet analytically pure product\ ðMo"CO#
"LÐP#"h1!MeC1Me#CpŁðBF3Ł "0# "yieldꢀ9[46 g\ 41)#[
Similar reactions of ðMo"CO#"h1!RC1R?#1CpŁðBF3Ł
with equimolar quantities of L\L? or Lý in CH1Cl1 at
room temperature gave the bimetallic complexes\ ðMo
"CO#"L\L? or LýÐP#"h1!RC1R?#CpŁðBF3Ł "on Mo centre
RꢀR?ꢀMe\Ph^ RꢀMe\ R?ꢀPh^ L\RꢀR?ꢀMe^
L?\RꢀR?ꢀPh^ Lý\RꢀMe\ R?ꢀPh# "1Ð8# "see Table 0
for physical and analytical data#[
aSpectra recorded as thin CH1Cl1 _lms between NaCl plates[
brꢀbroad^ sꢀstrong[
phine ligands\ ðWI1"CO#"PhP"CH1CH1PPh1#1ÐP\P?#"h1!
RC1R?#Ł "RꢀR?ꢀMe\Ph^ RꢀMe\ R?ꢀPh# were syn!
thesised by treating the bis"alkyne# complexes\ ðWI1
"CO#"NCMe#"h1!RC1R?#1Ł "RꢀR?ꢀMe\Ph^ RꢀMe\
R?ꢀPh# ð19Ł with one equivalent of linear triphos\
PhP"CH1CH1PPh1#1 in CH1Cl1 at room temperature ð07Ł[
Reaction of equimolar amounts of ðMo"CO#"h1!
RC1R?#1CpŁðBF3Ł "RꢀR?ꢀMe\Ph^ RꢀMe\ R?ꢀPh# and
L\L? or Lý "L\L? or LýꢀðWI1"CO#"PhP"CH1CH1PPh1#1Ð
P\P?#"h1!RC1R?#Ł "L\RꢀR?ꢀMe^ L?\RꢀR?ꢀPh^ Lý\
RꢀMe\ R?ꢀPh# in CH1Cl1 at room temperature yielded
the bimetallic linear triphos!bridged complexes ðMo
"CO#"L\L? or Lý!P#"h1!RC1R?#CpŁðBF3Ł "0Ð8# in good
yield[
2[ Results and discussion
The molybdenum starting materials used in this
research\ ðMo"CO#"h1!RC1R?#1CpŁðBF3Ł "RꢀR?ꢀMe\
Ph^ RꢀMe\ R?ꢀPh# were prepared by the oxidative!
cleavage of the MoÐMo bond in ð"Mo"CO#2Cp#1Ł with
AgðBF3Ł in the presence of RC1R? as described by Bottrill
and Green ð08Ł[ The organotungsten monodentate phos!
Complexes 0Ð8 have been characterised by elemental
0
analysis "C\ H and N# Table 0\ IR "Table 1#\ and H
NMR spectroscopy\ and in selected cases by 20 P NMR
spectroscopy "Table 2#[ Complexes 0Ð8 are all moderately
soluble in CH1Cl1 and CHCl2\ but as expected totally

P[K[ Baker\ D[E[ Belcher:Polyhedron 07 "0888# 618Ð622
620
Table 2
0H and selected 20 P "0H # NMR dataa for the bimetallic complexes ðMo"CO#"L\L? or Lý!P#"h1!RC1R?#CpŁðBF3Ł "0Ð8#
Complex 0H "d# "ppm# 20 P "d# "ppm#:J "Hz#
0
1
2
3
4
6[6Ð6[9 "br m\ 14H\ Ph#^ 5[14\ 5[24 "1s\ 4H\ Cp#^ 2[0\ 2[9\ 1[7\ 1[64 "3s\ 01H\ C1Me#^
1[5Ð1[24 "m\ 7H\ PhPCH1CH1#
6[74Ð6[94 "br m\ 29H\ Ph#^ 5[1\ 5[04 "1s\ 4H\ Cp#^ 2[14\ 2[04\ 1[74 "2s\ 8H\ C1Me#^
1[54Ð1[24 "m\ 7H\ PhPCH1CH1#
6[6Ð6[5 "br m\ 24H\ Ph#^ 4[6\ 4[5 "1s\ 4H\ Cp#^ 2[0\ 1[7\ 1[5 "2s\ 5H\ C1Me#^ 1[5Ð1[24
"m\ 7H\ PhPCH1CH1#
6[6Ð5[6 "br m\ 24H\ Ph#^ 4[6\ 4[5 "1s\ 4H\ Cp#^ 2[0\ 1[7\ 1[5 "2s\ 5H\ C1Me#^ 1[5Ð1[24
"m\ 7H\ PhPCH1CH1#
6[6Ð6[9 "br m\ 39H\ Ph#^ 4[54\ 4[44 "1s\ 4H\ Cp#^ 2[14 "s\ 2H\ C1Me#^ 1[5Ð1[24 "m\ 7H\
PhPCH1CH1#
−
38[5 "s#^ 37[4 "s#^ 12[38 "s#^ 08[7 "s#^ 3[22 "s#
38[93 "s#^ 36[80 "s#^ 12[24 "s#^ 08[7 "s#^ 1[49
"d# ðJꢀ34[34 HzŁ
−
38[48 "s#^ 37[56 "s#^ 15[54 "s#^ 19[65 "s#^
−2[93 "d# ðJꢀ27[27 HzŁ
5
6
7[9Ð6[9 "br m\ 34H\ Ph#^ 4[5\ 4[4 "1s\ 4H\ Cp#^ 1[5Ð1[24 "m\ 7H\ PhPCH1CH1#
6[6Ð6[1 "br m\ 29H\ Ph#^ 4[4\ 4[24 "1s\ 4H\ Cp#^ 2[04 "s\ 8H\ C1Me#^ 1[6Ð1[3 "m\ 7H\
PhPCH1CH1#
6[44Ð6[94 "br m\ 24H\ Ph#^ 4[54\ 4[44 "1s\ 4H\ Cp#^ 2[1 "s\ 5H\ C1Me#^ 1[5Ð1[24 "m\
7H\ PhPCH1CH1#
−
38[55 "d# ðJꢀ22[22 HzŁ^ 12[81 "s#^ 08[72
"d# ðJꢀ20[20 HzŁ^ −9[64 "s#^ −0[82 "s#
37[59 "s#^ 12[67 "s#^ 6[90 "s#^ −0[95 "s#^
−1[91 "s#
7
8
6[64Ð6[04 "br m\ 39H\ Ph#^ 4[6\ 4[5 "1s\ 4H\ Cp#^ 2[1 "s\ 2H\ C1Me#^ 1[5Ð1[3 "m\ 7H\
PhPCH1CH1#
−
aSpectra recorded in CDCl2 "¦14>C# and referenced to SiMe3 "0H# and 74) H2PO3 "20 P "0H # #[brꢀbroad\ sꢀsinglet\ dꢀdoublet\ mꢀmultiplet[
insoluble in diethyl ether and hydrocarbon solvents[ The
1!butyne complexes are the most soluble\ and the
diphenylacetylene complexes are the least soluble[ Com!
plexes 0Ð8 are all air!sensitive in solution\ but can be
stored in the solid state under dinitrogen[
the di}erence in the electron donating ability of PPh2 and
the pendant\ Ph1PCH1CH1 on the linear triphos would
not be expected to be very di}erent[ Complexes 0Ð8 all
showed alkyne stretching bands "Table 1# at considerably
lower wavenumber compared to the uncoordinated
alkyne ligands[ The "C2C# stretching bands for unco!
ordinated MeC1Me and MeC1Ph are 1202 and 1159 cm−0
respectively[ The carbonyl stretching bands for com!
plexes 0Ð8 are in a narrow range "y"CO#ꢀ0850 to
0879 cm−0#\ and no real trend exists for the variation of
R on the alkyne to the carbonyl and alkyne stretching
bands\ which are also in a narrow range "y"C2C#ꢀ0549
to 0575 cm−0#[ All complexes 0Ð8 have strong broad
bands at y"BF#ꢀ0989 cm−0 due to the tetra~uoroborate
anion\ which con_rms the cationic nature of these com!
plexes[
It is likely that the reactions of ðMo"CO#"h1!
RC1R?#1CpŁðBF3Ł with an equimolar amount of L\L? or
Lý "L\L? or LýꢀðWI1"CO#"PhP"CH1CH1PPh1#1Ð
P\P?#"h1!RC1R?#Ł proceed via associative mechanisms
involving the formation of the intermediates\ ðMo"C2
O#"L\L? or LýÐP# "h1!RC1R?#1CpŁðBF3Ł\ which have two
electron donating alkyne ligands\ before loss of alkyne to
give the observed products 0Ð8[ Green et al[ ð10Ł have
described the reactions of ðMo"CO#"h1!RC1R?#1"Cp or h4!
C8H6#ŁðBF3Ł with equimolar amounts of L to a}ord the
alkyne displaced complexes ðMo"CO#L"h1!RC1R?#"Cp or
h4!C8H6#ŁðBF3Ł " for Cp\ RꢀR?ꢀMe\ LꢀPEt2\ PPh2\
PCy2^ RꢀR?ꢀPh\ LꢀPEt2\ PPh2^ RꢀMe\ R?ꢀPh\
LꢀPEt2\ PPh2^ RꢀMe\ R?ꢀPh\ LꢀPPh2^ RꢀH\ R?ꢀ
iPr\ LꢀPPh2^ for h4!C8H6\ RꢀR?ꢀMe\ LꢀPEt2\ PPh2#\
and they proposed these reactions react by an associative
mechanism[
0
The H NMR spectra of 0Ð8 all have two cyclo!
pentadienyl resonances\ which indicates the presence of
two isomers[ The X!ray crystal structure of the 1!butyne
complex
ðWI1"CO#"PhP"CH1CH1PPh1#1ÐP\P?#"h1!Me
C1Me#Ł shows the complex crystallises as two dias!
tereoisomers in the single crystal chosen for X!ray crys!
tallography ð07Ł\ in an approximately 0]0 ratio[ One
diastereoisomer has the uncoordinated CH1CH1PPh1
group pointing up\ and the other pointing down[ This is
also observed in solution as shown by its20 P NMR spec!
trum ð07Ł[ Since the structure of ðMo"CO#"PEt2#"h1!Me
C1Me#CpŁðBF3Ł has been crystallographically determined
ð10Ł\ the likely structure of the two diastereoisomers of
for example\ complex 0 are shown in Fig[ 0[ The 20 P "0H #
NMR spectra of 1\ 2\ 4\ 6 and 7 all show 4 resonances
"Table 2# which is similar to the two diastereoisomers
The IR spectra of complexes 0Ð8 all have a very broad
carbonyl band which can be attributed to a combination
of the carbonyl stretching band on the molybdenum"II#
and tungsten"II# metal centres[ This was expected since
the carbonyl stretching bands as a nujol mull for the
1!butyne triphenylphosphine molybdenum"II# complex\
ðMo"CO#"PPh2#"h1!MeC1Me#CpŁðBF3Ł is 0862 cm−0\ and
for the 1!butyne linear triphos tungsten"II# complex
ðWI1"CO#"PhP"CH1CH1PPh1#1ÐP\P?#"h1!MeC1Me#Ł is
0846 cm−0[ These stretching frequencies are similar\ and

621
P[K[ Baker\ D[E[ Belcher:Polyhedron 07 "0888# 618Ð622
Fig[ 0[ Proposed structures of the two diastereoisomers of ðMo"CO#"LÐP#"h1!MeC1Me#CpŁðBF3Ł "0#[
of ðWI1"CO#"PhP"CH1CH1PPh1#1ÐP\P?#"h1!MeC1Me#Ł
ð07Ł\ which has resonances at d "CDCl2\ ¦14>C ref!
erenced to 74) H2PO3# at −02[6 "m\ 1P\ CH1CH1PPh1
"uncoord##\ −1[6 "s\ 0P\ CH1CH1PPh1#\ 3[2 "s\ 0P\
CH1CH1PPh#\ 08[4 "d\ 0P\ JPPꢀ29\ CH1CH1PPh1#\ 12[0
"d\ 0P\ JPPꢀ14\ CH1CH1PPh1#[ As expected the res!
onance at dꢀ−02[6 due to the uncoordinated phos!
phorus atom in ðWI1"CO#"PhP"CH1CH1PPh1#1!P\P?#"h1!
MeC1Me#Ł is not observed in complexes 1\ 2\ 4\ 6 and 7[
The 20 P "0H # NMR data also conform to the two dias!
tereoisomers shown in Fig[ 0[ A number of unsuccessful
attempts to grow suitable single crystals for X!ray analy!
sis of 0Ð8 were made[ Due to the moderate solubility
of these complexes in CD1Cl1 or d5!acetone\ it was not
possible to obtain satisfactory02 C NMR spectra of com!
plexes 0Ð8[
In conclusion\ this paper describes the successful syn!
thesis of a series of nine bimetallic complexes of the type
ðMo"CO#"L\L? or Lý#"h1!RC1R?#CpŁðBF3Ł "L\L? or
Lý ꢀ ðWI1"CO#"PhP"CH1CH1PPh1#1ÐP\P?#"h1!RC1R?#Ł
"L\ RꢀR?ꢀMe^ L?\ RꢀR?ꢀPh^ Lý\ RꢀMe\ R?ꢀPh#
and in general their IR properties do not re~ect the
expected trend in going from MeC1Me to MeC1Ph to
PhC1Ph[
Acknowledgements
D[ E[ B[ thanks the European Social Fund for support[
References
ð0Ł Albers MO\ Liles DC\ Robertson DJ\ Singleton E[ Organ!
ometallics 0876^5]1068[
ð1Ł Porschke KR\ Tsay Y!H\ Kruger C[ Inorg Chem 0875^14]1986[
Ã
Ã
ð2Ł Manojlovꢂ(c!Muir L\ Muir KW\ Frew AA\ Ling SSM\ Thomson
MA\ Puddephatt RJ[ Organometallics 0873^2]0526[
ð3Ł Green MLH\ Walker NM[ J Chem Soc Chem Commun 0878]0754[
ð4Ł Nadasdi TT\ Huang Y\ Stephan DW[ Inorg Chem 0882^21]236[
ð5Ł Hessen B\ van Bolhuis F\ Teuben JH\ Petersen JL[ J Am Chem
Soc 0877^009]184[
ð6Ł Kakker AK\ Taylor NJ\ Marder TB[ Organometallics 0878^7]0654[
ð7Ł Del Zotto A\ Mezzetti A\ Novelli V\ Rigo P\ Lanfranchi M\
Tiripicchio A[ J Chem Soc Dalton Trans 0889]0924[
ð8Ł Blagg A\ Hutton AT\ Pringle PG\ Shaw BL[ J Chem Soc Dalton
Trans 0873\ 0704[
ð09Ł Iggo JA\ Shaw BL[ J Chem Soc Dalton Trans 0874^0998[
ð00Ł Jacobsen GB\ Shaw BL\ Thornton!Pett M[ J Chem Soc Dalton
Trans 0876]1060[
ð01Ł Gaughan AP\ Ziolo RF\ Dori Z[ Inorg Chem 0860^09]1665[
ð02Ł Hunt CT\ Balch AL[ Inorg Chem 0870^19]1156[

P[K[ Baker\ D[E[ Belcher:Polyhedron 07 "0888# 618Ð622
ð03Ł Schmidbaur H\ Wohlleben A\ Wagner F\ Orama D\ Huttner G[ ð08Ł Bottrill M\ Green M[ J Chem Soc Dalton Trans 0866^1254[
622
Ã
Chem Ber 0866^009]0637[
ð04Ł Hewertson W\ Watson HR[ J Chem Soc 0851^0389[
ð05Ł King RB\ Kapoor PN[ J Am Chem Soc 0860^82]3047[
ð19Ł Armstrong EM\ Baker PK\ Drew MGB[ Organometallics
0877^6]208[
ð10Ł Allen SR\ Baker PK\ Barnes SG\ Green M\ Trollope L\
ð06Ł Horng D!N\ Jeng S!T\ Ueng C!H[ J Chin Chem Soc 0883^30]428[
ð07Ł Baker PK\ Coles SJ\ Hibbs DE\ Meehan MM\ Hursthouse MB[ J
Chem Soc Dalton Trans 0885^2884[
Manojlov(c!Muir L\ Muir KW[ J Chem Soc Dalton Trans 0870^
ꢂ
762[