Toward highly metallized polymers: Synthesis and characterization of silicon-bridged [1]Ferrocenophanes with pendent cluster substituents

Article abstract of DOI:10.1021/om030352p

The acetylide-substituted sila[1]ferrocenophanes [Fe(η-C₅H₄)₂Si(Me)C≡CR] (R = Ph (2a), ⁿBu (2b)) reacted with [Co₂(CO)₈], [{MoCp(CO)₂}₂], or [Ni(cod)₂]/L selectively at the triple bond to give pendent organocobalt [Fe(η-C₅H₄)₂Si(Me){Co₂(CO)₆ C₂R}] (R = Ph (4a), ⁿBu (4b)) or organomolybdenum [Fe(η-C₅H₄)₂Si(Me){Mo₂ Cp₂(CO)₄C₂Ph}] (9) clusters or mononuclear organonickel [Fe(η-C₅H₄)₂Si(Me) {Ni(L)C₂Ph}](L = dmpe (11), L = dppe (12)) complexes. The bis(acetylide)-substituted sila[1]ferrocenophanes [Fe(η-C₅H₄)₂Si(C≡CR)₂] (R = ⁿBu (6a), Ph (6b)) reacted with [Co₂(CO)₈] in an analogous fashion, forming the novel pentametallic silicon-bridged [1]ferrocenophanes with two pendent cobalt clusters [Fe(η-C₅H₄)₂Si{Co₂ (CO)₆C₂R}₂] (R = ⁿBu (7a), R = Ph (7b)). Compound 7b subsequently underwent rapid hydrolytic ring-opening to yield an unusual, highly metallized silanol, [(η-C₅H₅) Fe(η-C₅H₄)Si(OH){Co₂(CO)₆ C₂Ph}₂] (8b). This reaction was found to be much slower for the hexynyl analogue (7a). The organonickel complexes (11 and 12) described in this work represent the first examples of mononuclear complexes prepared directly from an alkyne and [Ni(cod)₂]. We postulate that steric factors prevent the addition of a second nickel fragment to the alkyne. The synthesis of a sila[1]ferrocenophane with a pendent platinum moiety was also attempted. However, reaction of 2a with [Pt(PEt₃)₃] instead gave the platinasila[2]-ferrocenophane [Fe(η-C₅ H₄)₂Pt(PEt₃)₂ Si(Me)C≡CPh] (15) via oxidative insertion of the platinum(0) fragment into a strained ipso-cyclopentadienyl carbon-silicon bond of the sila[1]ferrocenophane.

Full text of DOI:10.1021/om030352p

3796
Organometallics 2003, 22, 3796-3808
Articles
Tow a r d High ly Meta llized P olym er s: Syn th esis a n d
Ch a r a cter iza tion of Silicon -Br id ged [1]F er r ocen op h a n es
w ith P en d en t Clu ster Su bstitu en ts
Wing Yan Chan, Andrea Berenbaum, Scott B. Clendenning, Alan J . Lough, and
Ian Manners*
Department of Chemistry, University of Toronto, 80 St. George Street,
Toronto, Ontario, Canada, M5S 3H6
Received May 12, 2003
The acetylide-substituted sila[1]ferrocenophanes [Fe(η-C5H4)2Si(Me)CtCR] (R ) Ph (2a ),
nBu (2b)) reacted with [Co2(CO)8], [{MoCp(CO)2}2], or [Ni(cod)2]/L selectively at the triple
bond to give pendent organocobalt [Fe(η-C5H4)2Si(Me){Co2(CO)6C2R}] (R ) Ph (4a ), nBu (4b))
or organomolybdenum [Fe(η-C5H4)2Si(Me){Mo2Cp2(CO)4C2Ph}] (9) clusters or mononuclear
organonickel [Fe(η-C5H4)2Si(Me){Ni(L)C2Ph}] (L ) dmpe (11), L ) dppe (12)) complexes.
The bis(acetylide)-substituted sila[1]ferrocenophanes [Fe(η-C5H4)2Si(CtCR)2] (R ) nBu (6a ),
Ph (6b)) reacted with [Co2(CO)8] in an analogous fashion, forming the novel pentametallic
silicon-bridged [1]ferrocenophanes with two pendent cobalt clusters [Fe(η-C5H4)2Si{Co2-
n
(CO)6C2R}2] (R ) Bu (7a ), R ) Ph (7b)). Compound 7b subsequently underwent rapid
hydrolytic ring-opening to yield an unusual, highly metallized silanol, [(η-C5H5)Fe(η-C5H4)-
Si(OH){Co2(CO)6C2Ph}2] (8b). This reaction was found to be much slower for the hexynyl
analogue (7a ). The organonickel complexes (11 and 12) described in this work represent the
first examples of mononuclear complexes prepared directly from an alkyne and [Ni(cod)2].
We postulate that steric factors prevent the addition of a second nickel fragment to the
alkyne. The synthesis of a sila[1]ferrocenophane with a pendent platinum moiety was also
attempted. However, reaction of 2a with [Pt(PEt3)3] instead gave the platinasila[2]-
ferrocenophane [Fe(η-C5H4)2Pt(PEt3)2Si(Me)CtCPh] (15) via oxidative insertion of the
platinum(0) fragment into a strained ipso-cyclopentadienyl carbon-silicon bond of the sila-
[1]ferrocenophane.
In tr od u ction
chemical characteristics.1,2 However, despite the sig-
nificant expansion of the metallopolymer area over the
past decade or so, most materials reported to date still
contain relatively low concentrations of metal atoms.
Metal cluster complexes exhibit many useful catalytic,
optical, and other potentially useful properties for
materials science applications.9 The incorporation of
these remarkable metallo units into high molecular
weight, processable polymers clearly offers exciting
Polymers containing metal atoms as part of the main
chain or side group structure are attracting increasing
attention as they offer potential access to new functional
macromolecular and supramolecular materials with
novel properties.1,2 For example, the presence of transi-
tion metal centers in a polymer allows redox control of
the size and shape of a macroscopic object;3 the “wiring”
of enzymes to electrodes;4 selective binding and sens-
ing;5 the generation of liquid crystallinity,6 magnetic
nanoparticle composites,7 supramolecular materials,8
and a wide variety of other desirable physical and
(5) (a) McQuade, D. T.; Pullen, A. E.; Swager, T. M. Chem. Rev. 2000,
100, 2537-2574. (b) Wang, Z.; McWilliams, A. R.; Evans, C. E. B.; Lu,
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(7) (a) MacLachlan, M. J .; Ginzburg, M.; Coombs, N.; Coyle, T. W.;
Raju, N. P.; Greedan, J . E.; Ozin, G. A.; Manners, I. Science 2000, 287,
1460-1463. (b) Temple, K.; Kulbaba, K.; Power-Billard, K. N.; Man-
ners, I.; Leach, K. A.; Xu, T.; Russell, T. P.; Hawker, C. J . Adv. Mater.
2003, 15, 297-300.
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Mater. 2002, 14, 1225-1230. (b) Massey, J . A.; Winnik, M. A.; Manners,
I.; Chan, V. Z.-H.; Ostermann, J . M.; Enchelmaier, R.; Spatz, J . P.;
Mo¨ller, M. J . Am. Chem. Soc. 2001, 123, 3147-3148.
* Correspondingauthor.E-mail: imanners@alchemy.chem.utoronto.ca.
Fax: (416) 978-6157.
(1) (a) Archer, R. D. Inorganic and Organometallic Polymers; J ohn
Wiley & Sons Inc.: New York, 2001. (b) Manners, I. Science 2001, 294,
1664-1666.
(2) (a) Schubert, U. S.; Heller, M. Chem. Eur. J . 2001, 7, 5252-
5259. (b) Nguyen, P.; Go´mez-Elipe, P.; Manners, I. Chem. Rev. 1999,
99, 1515-1548.
(3) (a) Yoshida, R.; Takahashi, T.; Yamaguchi, T.; Ichijo, H. Adv.
Mater. 1997, 9, 175-178. (b) Arsenault, A. C.; M´ıguez, H.; Kitaev, V.;
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774.
10.1021/om030352p CCC: $25.00 © 2003 American Chemical Society
Publication on Web 08/21/2003

Toward Highly Metallized Polymers
Organometallics, Vol. 22, No. 19, 2003 3797
Sch em e 1. Rea ction of 2a a n d 2b w ith [Co2(CO)8]
a n d Syn th esis of 4a a n d 4b
possibilities, but in general, this area is very poorly
developed. In recent intriguing work, J ohnson and co-
workers have briefly reported the formation of a highly
metallized polymer based on the hexanuclear ruthenium
carbido species Ru6C(CO)15; this material is electron-
beam sensitive and can be used to fabricate ruthenium-
based nanoparticle chains and conducting wires.10 In
addition, Humphrey and co-workers have successfully
developed a polycondensation approach to yield well-
characterized polyurethanes containing tetrahedral
Mo2Ir2 clusters in the backbone with potentially inter-
esting nonlinear optical properties.11
Ring-opening polymerization (ROP) of strained met-
allocenophanes is a versatile methodology for the syn-
thesis of high molecular weight polymetallocenes that
exhibit a range of interesting characteristics.12,13 With
the aim of incorporating a higher concentration of
metals into these polymers, we have recently found that
sila[1]ferrocenophanes 2 with potentially ligating acety-
lenic substituents are readily accessible via the reaction
of sila[1]ferrocenophane 1 with an appropriate lithium
acetylide.14 ROP of species such as 2 yields polyferro-
cenylsilanes 3 with acetylide side groups.14 In a recent
communication,15 we have briefly reported that the
pendent acetylide substituents in both monomer 2a and
polymer 3a can be transformed into tetrahedral Co2C2
clusters on treatment with dicobalt octacarbonyl to
afford species 4a and 5a , respectively. We have also
shown that polymer 5a provides a route to ceramics
containing magnetic Co/Fe alloy nanoparticles in high
yield.15 In this paper we report full details of our studies
on the incorporation of additional metallo fragments via
complexation of the triple bond in acetylide-substituted
sila[1]ferrocenophanes. In future papers we will provide
details on the ROP behavior of these species and the
properties and applications of analogous high polymers.
species with ferrocenyl16 or [Co(CO)4]17 groups. To
provide a general route to such highly metallized
species, we explored complexation to sila[1]ferro-
cenophanes with one or two acetylenic side groups.
Syn th esis a n d Ch a r a cter iza tion of Sila [1]fer r o-
cen op h a n es w ith a P en d en t Or ga n ocoba lt Clu ster
(4a a n d 4b). Reaction of acetylide-substituted sila[1]-
ferrocenophanes 2a and 2b with a slight excess of
dicobalt octacarbonyl, [Co2(CO)8], in hexanes led to
selective clusterization of the triple bond with a dicobalt
hexacarbonyl fragment (Scheme 1). Importantly, ring-
opening of the sila[1]ferrocenophane was not observed,
in contrast to the situation for a tin-bridged analogue18
or a sila[1]ferrocenophane containing a silicon-hydro-
gen bond.17 After workup and recrystallization from
hexanes at -55 °C, we isolated cobalt-clusterized sila-
[1]ferrocenophanes 4a and 4b as red-purple solids in
yields of 65% and 80%, respectively.
The 1H NMR spectrum of 4a showed three resonances
for phenyl protons at δ ) 7.72 (ortho), 7.02 (meta), and
(11) (a) Lucas, N. T.; Humphrey, M. G.; Rae, A. D. Macromolecules
2001, 34, 6188-6195. (b) For some other work on cluster polymers,
see: Kuhnen, T.; Stradiotto, M.; Ruffolo, R.; Ulbrich, D.; McGlinchey,
M. J .; Brook, M. A. Organometallics 1997, 16, 5048-5057.
(12) (a) Foucher, D. A.; Tang, B.-Z.; Manners, I. J . Am. Chem. Soc.
1992, 114, 6246-6248. (b) Foucher, D. A.; Honeyman, C. H.; Nelson,
J . M.; Tang, B.-Z.; Manners, I. Angew. Chem., Int. Ed. Engl. 1993, 32,
1709-1711. (c) Rulkens, R.; Gates, D. P.; Balaishis, D.; Pudelski, J .
K.; McIntosh, D. F.; Lough, A. J .; Manners, I. J . Am. Chem. Soc. 1997,
119, 10976-10986. (d) Resendes, R.; Nelson, J . M.; Fischer, A.; J a¨kle,
F.; Bartole, A.; Lough, A. J .; Manners, I. J . Am. Chem. Soc. 2001, 123,
2116-2126. (e) Kulbaba, K.; Manners, I. Macromol. Rapid Commun.
2001, 22, 711-724.
(13) For work by other groups, see: (a) Sharma, H. K.; Cervantes-
Lee, F.; Mahmoud, J . S.; Pannell, K. H. Organometallics 1999, 18, 399-
403. (b) Mizuta, T.; Imamura, Y.; Miyoshi, K. J . Am. Chem. Soc. 2003,
125, 2068-2069. (c) Herberhold, M.; Hertel, F.; Milius, W.; Wrackm-
eyer, B. J . Organomet. Chem. 1999, 582, 352-357. (d) Calleja, G.;
Carre´, F.; Cerveau, G.; Labbe´, P.; Coche-Gue´rente, L. Organometallics
2001, 20, 4211-4215. (e) Mizuta, T.; Onishi, M.; Miyoshi, K. Organo-
metallics 2000, 19, 5005-5009. (f) Reddy, N. P.; Yamashita, H.;
Tanaka, M. J . Chem. Soc., Chem. Commun. 1995, 2263-2264. (g)
Bucaille, A.; Le Borgne, T.; Ephritikhine, M.; Daran, J .-C. Organome-
tallics 2000, 19, 4912-4914. (h) Osborne, A. G.; Whiteley, R. H. J .
Organomet. Chem. 1975, 101, C27-28. (i) Espada, L. I.; Shadaram,
M.; Robillard, J .; Pannell, K. H. J . Inorg. Organomet. Polym. 2000,
10, 169-176. (j) Broussier, R.; Da Rold, A.; Gautheron, B.; Dromzee,
Y.; J eannin, Y. Inorg. Chem. 1990, 29, 1817-1822. (k) Papkov, V. S.;
Gerasimov, M. V.; Dubovik, I. I.; Sharma, S.; Dementiev, V. V.; Pannell,
K. H. Macromolecules 2000, 33, 7107-7115. (l) Sun, Q.; Xu, K.; Peng,
H.; Zheng, R.; Ha¨ussler, M.; Tang, B.-Z. Macromolecules 2003, 36,
2309-2320.
(14) Berenbaum, A.; Lough, A. J .; Manners, I. Organometallics 2002,
21, 4415-4424.
Resu lts a n d Discu ssion
(15) Berenbaum, A.; Ginzburg-Margau, M.; Coombs, N.; Lough, A.
J .; Safa-Sefat, A.; Greedan, J . E.; Ozin, G. A.; Manners, I. Adv. Mater.
2003, 15, 51-55.
Silicon-bridged [1]ferrocenophanes with pendent met-
allo substituents are rare and at present are limited to
(16) (a) MacLachlan, M. J .; Zheng, J .; Thieme, K.; Lough, A. J .;
Manners, I.; Mordas, C.; LeSuer, R.; Geiger, W. E.; Liable-Sands, L.
M.; Rheingold, A. L. Polyhedron 2000, 19, 275-289. (b) Pannell, K.
H.; Dementiev, V. V.; Li, H.; Cervantes-Lee, F.; Nguyen, M. T.; Diaz,
A. F. Organometallics 1994, 13, 3644-3650, and references therein.
(17) Berenbaum, A.; J a¨kle, F.; Lough, A. J .; Manners, I. Organo-
metallics 2001, 20, 834-843.
(9) (a) Shriver, D. F.; Kaesz, H. D.; Adams, R. D. The Chemistry of
Metal Cluster Complexes; VCH Publishers Inc.: New York, 1990. (b)
Braunstein, P., Oro, L. A., Raithby, P. R., Eds. Metal Clusters in
Chemistry; VCH Publishers Inc.: New York, 1999.
(10) J ohnson, B. F. G.; Sanderson, K. M.; Shephard, D. S.; Ozkaya,
D.; Zhou, W.; Ahmed, H.; Thomas, M. D. R.; Gladden, L.; Mantle, M.
Chem. Commun. 2000, 1317-1318.
(18) Berenbaum, A.; J a¨kle, F.; Lough, A. J .; Manners, I. Organo-
metallics 2002, 21, 2359-2361.

3798 Organometallics, Vol. 22, No. 19, 2003
Ta ble 1. Selected Bon d Len gth s (Å) a n d Bon d An gles (d eg) for 4a
Chan et al.
Si(1)-C(1)
1.889(4)
1.892(4)
1.841(4)
1.334(5)
1.471(5)
1.964(4)
C(12)-Co(2)
C(13)-Co(1)
C(13)-Co(2)
Co(1)-Co(2)
Fe(1)-Si(1)
1.981(4)
1.971(4)
1.971(4)
2.4850(8)
2.6913(11)
96.52(16)
C(11)-Si(1)-C(12)
Si(1)-C(12)-C(13)
C(12)-C(13)-C(14)
Co(1)-C(13)-Co(2)
Co(2)-C(12)-Co(1)
R
111.70(18)
145.7(3)
142.9(3)
78.16(13)
78.07(13)
19.09(21)
Si(1)-C(6)
Si(1)-C(12)
C(12)-C(13)
C(13)-C(14)
C(12)-Co(1)
C(1)-Si(1)-C(6)
Ta ble 2. Selected Bon d Len gth s (Å) a n d Bon d An gles (d eg) for 4b
Si(1)-C(1)
1.878(4)
1.885(4)
1.832(4)
1.340(5)
1.491(5)
1.975(4)
C(12)-Co(2)
C(13)-Co(1)
C(13)-Co(2)
Co(1)-Co(2)
Fe(1)-Si(1)
1.992(4)
1.969(4)
1.975(4)
2.4859(8)
2.6804(12)
97.11(18)
C(11)-Si(1)-C(12)
Si(1)-C(12)-C(13)
C(12)-C(13)-C(14)
Co(1)-C(13)-Co(2)
Co(2)-C(12)-Co(1)
R
111.04(17)
150.5(3)
141.5(4)
78.16(13)
78.14(15)
19.51(19)
Si(1)-C(6)
Si(1)-C(12)
C(12)-C(13)
C(13)-C(14)
C(12)-Co(1)
C(1)-Si(1)-C(6)
6.96 (para) ppm, all significantly shifted downfield from
those of 2a (δ ) 7.50-7.47 (ortho), 6.95-6.92 (meta and
para) ppm).14 The methyl proton resonance also dis-
played a similar downfield shift (4a : δ ) 0.73 ppm; 2a :
δ ) 0.61 ppm).14 Downfield shifts of such magnitude are
common to the highly metallized sila[1]ferrocenophanes
in this work. We observed four resonances at δ ) 4.36,
4.34, 4.25, and 3.93 ppm for cyclopentadienyl (Cp)
protons; this pattern is characteristic of an unsymmetri-
cally substituted sila[1]ferrocenophane. The 13C{1H}
NMR spectrum of 4a showed one broad carbonyl reso-
nance at δ ) 200.1 ppm, likely due to spin-spin
coupling with the quadrupolar cobalt nuclei (I ) 7/2 for
59Co).19 Using CIGAR-HMBC spectroscopy,20 a reso-
nance at δ ) 107.1 ppm was assigned to the acetylenic
carbon bound to the phenyl group and a resonance at
δ ) 74.6 ppm was assigned to the acetylenic carbon
bound to silicon (cf. 2a : δ ) 107.7 and 89.7 ppm for CPh
and CSi, respectively).14 The ipso-Cp carbons of 4a
resonated at δ ) 33.6 ppm, downfield from those of 2a
(δ ) 30.4 ppm).14 The 29Si{1H} NMR spectrum of 4a
showed a singlet at δ ) -11.8 ppm, again shifted
downfield from that of 2a (δ ) -27.8 ppm).14 The four
carbonyl stretches in the infrared spectrum of 4a at
2091, 2055, 2030, and 2013 cm-1 suggested all carbonyl
ligands are terminal.
1
The H NMR spectrum of 4b is again consistent with
selective clusterization of the hexyne moiety, as reso-
nances for protons of the n-butyl chain in 4b are shifted
downfield from those in 2b. The 13C{1H} NMR spectrum
of 4b showed a broad carbonyl resonance at δ ) 200.6
ppm. The ipso-Cp carbons of 4b resonated at δ ) 34.2
ppm, slightly downfield to those of 4a (δ ) 33.6 ppm).
The 29Si{1H} NMR spectrum for 4b contained a singlet
at δ ) -12.5 ppm, significantly shifted downfield from
that of 2b (δ ) -29.1 ppm).14 As with 4a , the infrared
spectrum of 4b showed only terminal carbonyl stretches,
F igu r e 1. (a) Molecular structure of 4a . (b) Molecular
structure of 4b. For both structures, thermal ellipsoids are
displayed at 30% probability and hydrogen atoms have
been omitted for clarity.
that of unclusterized sila[1]ferrocenophane 2a (R )
20.53(14)°).14 The Fe-Si distances in 4a (2.6913(11) Å)
and 4b (2.6804(12) Å) fall within the normal range for
sila[1]ferrocenophanes (cf. d(Fe-Si) ) 2.55-2.75 Å).21,22
As found in other [Co2(CO)6C2R2] clusters, the Co-Co
axis in 4a and 4b is perpendicular to that of the
alkyne.23 Upon cobalt coordination, the geometry of the
alkyne moiety changed from linear to bent. The Si(1)-
C(12)-C(13) angles in 4a and 4b were 145.7(3)° and
150.5(3)°, respectively, and the C(12)-C(13)-C(14)
at 2089, 2051, and 2021 cm-1
.
To confirm the assigned structures and compare
structural details, single-crystal X-ray diffraction stud-
ies were performed for 4a and 4b. Figure 1 shows the
two molecular structures; Tables 1 and 2 list selected
bond lengths and bond angles.
The molecular structures of 4a and 4b confirmed the
expected atom connectivity. The tilt angles between
the Cp rings (R) in 4a and 4b were 19.09(21)° and
19.51(19)°, respectively; these are slightly smaller than
(21) Pudelski, J . K.; Foucher, D. A.; Honeyman, C. H.; Lough, A. J .;
Manners, I.; Barlow, S.; O’Hare, D. Organometallics 1995, 14, 2470-
2479.
(22) Zechel, D. L.; Hultzsch, K. C.; Rulkens, R.; Balaishis, D.; Ni,
Y.; Pudelski, J . K.; Lough, A. J .; Manners, I.; Foucher, D. A. Organo-
metallics 1996, 15, 1972-1978.
(23) Gregson, D.; Howard, J . A. K. Acta Crystallogr. 1983, C39,
1024-1027.
(19) Aime, S.; Milone, L.; Rossetti, R.; Stanghellini, P. L. Inorg.
Chim. Acta 1977, 22, 135-139.
(20) Hadden, C. E.; Martin, G. E.; Krishnamurthy, V. V. Magn.
Reson. Chem. 2000, 38, 143-147.

Toward Highly Metallized Polymers
Organometallics, Vol. 22, No. 19, 2003 3799
Ta ble 3. Selected Bon d Len gth s (Å) a n d Bon d An gles (d eg) for 7a
Si(1)-C(1)
1.887(3)
1.887(3)
1.859(3)
1.844(3)
1.333(4)
1.345(4)
1.502(4)
1.495(4)
1.979(3)
1.965(3)
Co(2)-C(18)
Co(3)-C(30)
Co(1)-C(17)
Co(4)-C(29)
Co(2)-C(17)
Co(3)-C(29)
Co(1)-Co(2)
Co(3)-Co(4)
Fe(1)-Si(1)
C(1)-Si(1)-C(6)
1.962(3)
1.961(3)
2.004(3)
2.003(3)
1.997(3)
2.009(3)
2.4811(6)
2.4649(6)
2.6913(9)
96.52(13)
C(17)-Si(1)-C(29)
Si(1)-C(17)-C(18)
Si(1)-C(29)-C(30)
C(17)-C(18)-C(19)
C(29)-C(30)-C(31)
Co(1)-C(18)-Co(2)
Co(3)-C(30)-Co(4)
Co(1)-C(17)-Co(2)
Co(3)-C(29)-Co(4)
R
114.72(13)
144.4(2)
148.6(2)
148.2(3)
143.3(3)
78.03(11)
77.78(11)
76.65(10)
75.81(11)
19.87(22)
Si(1)-C(6)
Si(1)-C(17)
Si(1)-C(29)
C(17)-C(18)
C(29)-C(30)
C(18)-C(19)
C(30)-C(31)
Co(1)-C(18)
Co(4)-C(30)
Sch em e 2. Rea ction of 6a a n d 6b w ith [Co2(CO)8]
a n d Syn th esis of 7a a n d 7b
angles were 142.9(3)° and 141.5(4)°. The Co(1)-Co(2)
distances in 4a (2.4850(8) Å) and 4b (2.4859(8) Å) are
typical for clusters of disubstituted alkynes (d(Co-Co)
) 2.460-2.477 Å).23
Syn th esis a n d Ch a r a cter iza tion of a Sila [1]-
fer r ocen op h a n e Con ta in in g Tw o Coba lt Clu ster s
(7a ). To increase the metal content of sila[1]ferro-
cenophanes still further, we explored the analogous
complexation of the novel bis(acetylide) monomer 6a .
In a synthesis similar to that of 4a and 4b, we reacted
6a with excess [Co2(CO)8] in hexanes to form 7a
(Scheme 2). We found that it was important to use an
excess of the cobalt reagent, as the use of a stoichio-
metric amount gave a mixture of products with either
one or two clusterized alkyne moieties. After workup
and recrystallization from hexanes at -35 °C, we
isolated 7a as a dark brown solid (yield ) 63%).
F igu r e 2. Molecular structure of 7a (thermal ellipsoids
at 30% probability). Hydrogen atoms have been removed
for clarity.
2.4649(6) Å, respectively; the slight asymmetry of the
two clusters is probably a result of crystal-packing
forces.
Isola tion of a n Un exp ected Sid e P r od u ct; Hy-
d r olytic Rin g-Op en in g of 7b to F or m a Sila n ol (8b).
When a benzene solution of 7a was left at 25 °C, new
1
The H NMR spectrum of 7a showed two resonances
1
for the R- and â-Cp protons at δ ) 4.54 and 4.51 ppm,
respectively (cf. 6a : δ ) 4.48 and 4.42 ppm); this pattern
is characteristic of a symmetrically substituted sila[1]-
ferrocenophane. We observed four resonances at δ )
3.15, 1.84, 1.35, and 0.89 ppm for the four different types
of protons on the n-butyl chains, shifted downfield from
those of 6a (δ ) 2.01, 1.29, and 0.73 ppm). The 13C{1H}
and 29Si{1H} NMR spectra of 7a are similar to those of
4b and are consistent with the assigned structure. The
infrared spectrum of 7a contained three terminal car-
resonances appeared in the H NMR spectrum after 1
day. Among the new signals, the singlet at δ ) 4.05 ppm
is characteristic for a C5H5 moiety and suggests ring-
opening of the sila[1]ferrocenophane to afford 8a .24
When we prepared 7b (the phenylacetylide analogue of
7a ) from 6b and [Co2(CO)8], we found that this conver-
sion was even more facile. Over a three-week recrys-
tallization, the desired product 7b quantitatively con-
verted to the corresponding ring-opened product 8b
(Scheme 3), which was fully characterized. The 1H NMR
spectrum of 8b contained a singlet at δ ) 4.05 ppm for
protons of the free Cp ligand, whereas protons of the
other Cp ligand resonated at δ ) 4.57 and 4.24 ppm. A
singlet at δ ) 2.84 ppm was assigned to a silanol -OH
group. The 13C{1H} NMR spectrum of 8b contained a
broad carbonyl resonance at δ ) 200.0 ppm. We ob-
served five Cp carbon resonances between δ ) 74.7 and
69.1 ppm, in contrast to two for sila[1]ferrocenophane
7a . The 29Si{1H} NMR spectrum of 8b contained a
singlet at δ ) -13.4 ppm. In the IR spectrum of 8b,
four terminal carbonyl stretches were found at 2087,
bonyl stretches, at 2084, 2056, and 2026 cm-1
.
To confirm the assigned structure, we performed a
single-crystal X-ray diffraction study for 7a . Figure 2
shows the molecular structure of 7a , and Table 3 lists
selected bond lengths and bond angles.
The molecular structure of 7a was as expected. The
tilt angle (19.87(22)°) and Fe-Si distance (2.6913(9) Å)
in 7a were very similar to those in the sila[1]ferro-
cenophane containing one cobalt-clusterized hexynyl
substituent (cf. 4b : R ) 19.51(19)°, d(Fe-Si) )
2.6804(12) Å). Both hexynyl moieties in 7a exhibited a
bent geometry, with bond angles around the alkyne
carbons ranging from ca. 143° to 149°. The Co(1)-
Co(2) and Co(3)-Co(4) distances were 2.4811(6) and
2054, 2026, and 2009 cm-1
.
(24) Fischer, A. B.; Kinney, J . B.; Staley, R. H.; Wrighton, M. S. J .
Am. Chem. Soc. 1979, 101, 6501-6506.

3800 Organometallics, Vol. 22, No. 19, 2003
Ta ble 4. Selected Bon d Len gth s (Å) a n d Bon d An gles (d eg) for 8b
Chan et al.
Si(1)-C(1)
1.845(2)
1.843(3)
1.840(2)
1.340(3)
1.346(3)
1.459(3)
1.463(3)
1.992(2)
2.002(2)
2.021(2)
1.997(2)
Co(1)-C(12)
1.959(3)
1.969(2)
1.978(2)
1.981(2)
2.4637(5)
2.4588(4)
1.656(2)
109.59(11)
150.3(2)
149.45(19)
143.6(2)
C(25)-C(26)-C(33)
Co(1)-C(11)-Co(2)
Co(3)-C(25)-Co(4)
Co(1)-C(12)-Co(2)
Co(3)-C(26)-Co(4)
C(1)-Si(1)-C(11)
C(1)-Si(1)-C(25)
C(1)-Si(1)-O(13)
C(11)-Si(1)-C(25)
C(11)-Si(1)-O(13)
C(25)-Si(1)-O(13)
140.3(2)
75.74(9)
75.88(8)
77.49(9)
Si(1)-C(11)
Si(1)-C(25)
C(11)-C(12)
C(25)-C(26)
C(12)-C(19)
C(26)-C(33)
Co(1)-C(11)
Co(3)-C(25)
Co(2)-C(11)
Co(4)-C(25)
Co(3)-C(26)
Co(2)-C(12)
Co(4)-C(26)
Co(1)-Co(2)
76.99(8)
Co(3)-Co(4)
108.07(11)
113.72(11)
110.14(11)
109.59(11)
105.94(11)
109.08(11)
Si(1)-O(13)
C(11)-Si(1)-C(25)
Si(1)-C(11)-C(12)
Si(1)-C(25)-C(26)
C(11)-C(12)-C(19)
Sch em e 3. Rin g-Op en in g of 7a a n d 7b to F or m
Sila n ols 8a a n d 8b
To further confirm the structure of the ring-opened
product, we performed a single-crystal X-ray diffraction
study for 8b. Figure 3 shows the molecular structure of
8b, and Table 4 lists selected bond lengths and bond
angles.
F igu r e 3. Molecular structure of 8b (thermal ellipsoids
at 30% probability). Hydrogen atoms have been removed
for clarity.
The molecular structure of 8b shows two intact cobalt
clusters, in agreement with the assigned structure. The
ring-opening reaction had little effect on the structure
of the cobalt clusters, as the cobalt-cobalt and acety-
lenic bond lengths showed minimal changes. The silicon
atom of 8b displayed a distorted tetrahedral geometry,
with bond angles around silicon ranging from ca. 106°
to 114°. The presence of two bulky cobalt-clusterized
phenylacetylene substituents led to a larger than ideal
C(1)-Si(1)-C(25) angle (113.72(11)°) and a smaller than
ideal C(11)-Si(1)-O(13) angle (105.94(11)°). No inter-
molecular hydrogen bonding is apparent, presumably
due to the steric bulk around silicon. The lack of
hydrogen bonding is in contrast to the situation for
many other ferrocenyl silanol species.16a,25
Sch em e 4. Rea ction of 2a w ith [{MoCp (CO)2}2]
a n d Syn th esis of 9
(para) ppm, downfield to those of 2a .14 Upon coordina-
tion, the resonance for protons of the Cp rings bound to
molybdenum shifted downfield from δ ) 4.62 to 4.99
ppm. The 13C{1H} NMR spectrum of 9 contained two
resonances in the carbonyl region: a broad signal at δ
≈ 233 ppm and a sharp signal at δ ) 230.5 ppm.
However, we would expect four carbonyl resonances
when [{MoCp(CO)2}2] coordinates to an unsymmetrical
alkyne to form a Mo2C2 core. On the basis of a previous
variable-temperature NMR study of [Cp2Mo2(CO)4-
(RCtCR′)] complexes,26 this observation can be ex-
plained by the simultaneous occurrence of a low-energy
and a higher-energy process. The low-energy process
interconverts the two molybdenum atoms, the two Cp
ligands, and the two pairs of carbonyl ligands; the
higher-energy process allows partial rotation of the Mo-
Mo bond. As a result, only two types of carbonyl ligands
are observed at 25 °C. The presence of a single molyb-
denum Cp resonance at δ ) 92.2 ppm also supports this
explanation. Upon coordination to molybdenum, the
resonance for ipso-Cp carbons shifted downfield from δ
) 30.4 to 37.8 ppm. We observed a singlet at δ ) -3.8
ppm in the 29Si{1H} NMR spectrum of 9, significantly
shifted downfield from that of 2a (δ ) -27.8 ppm).14
Syn th esis a n d Ch a r a cter iza tion of a Sila [1]-
fer r ocen op h a n e w ith P en d en t Or ga n om olybd e-
n u m Clu ster s (9). To expand the clusterization chem-
istry to other metals, we explored complexation of the
acetylide group of 2a using an organomolybdenum
reagent. Overnight heating of a toluene solution of 2a
and [{MoCp(CO)2}2] at 75 °C resulted in addition of a
dimolybdenum unit to the triple bond of the phenyl-
acetylene substituent (Scheme 4). After workup and
recrystallization from a mixture of hexanes and dichlo-
romethane at -35 °C, we isolated 9 as a dark red-purple
solid (yield ) 38%). The same clusterization through
decarbonylation of [{MoCp(CO)3}2] proved sluggish,
with less than 10% conversion after 21 h at 85 °C in
tetrahydrofuran.
The 1H NMR spectrum of 9 contained phenyl reso-
nances at δ ) 7.67 (ortho), 7.18-7.12 (meta), and 6.92
(25) For some recent work on ferrocenyl silanols, see: (a) Ma-
cLachlan, M. J .; Zheng, J .; Lough, A. J .; Manners, I.; Mordas, C.;
LeSuer, R.; Geiger, W. E.; Liable-Sands, L. M.; Rheingold, A. L.
Organometallics 1999, 18, 1337-1345. (b) Reyes-Garc´ıa, E. A.; Cer-
vantes-Lee, F.; Pannell, K. H. Organometallics 2001, 20, 4734-4740.
(26) Bailey, W. I., J r.; Chisholm, M. H.; Cotton, F. A.; Rankel, L. A.
J . Am. Chem. Soc. 1978, 100, 5764-5773.

Toward Highly Metallized Polymers
Organometallics, Vol. 22, No. 19, 2003 3801
Ta ble 5. Selected Bon d Len gth s (Å) a n d Bon d An gles (d eg) for 9
Si(1)-C(1)
1.894(4)
1.899(3)
1.841(4)
1.366(5)
1.482(5)
2.181(3)
Mo(2)-C(27)
Mo(1)-C(28)
Mo(2)-C(28)
Mo(1)-Mo(2)
Fe(1)-Si(1)
2.200(3)
2.240(3)
2.170(3)
2.9625(4)
2.7202(11)
95.18(16)
C(28)-Si(1)-C(33)
C(27)-C(28)-Si(1)
C(21)-C(27)-C(28)
Mo(1)-C(27)-Mo(2)
Mo(1)-C(28)-Mo(2)
R
113.16(17)
142.2(3)
136.4(3)
85.11(12)
84.40(12)
20.93(20)
Si(1)-C(6)
Si(1)-C(28)
C(27)-C(28)
C(21)-C(27)
Mo(1)-C(27)
C(1)-Si(1)-C(6)
Sch em e 5. Top : Rea ction of 2a w ith [Ni(cod )2] to
F or m 10. Bottom : Rea ction of 2a w ith [Ni(cod )2]
a n d d m p e or d p p e a n d Syn th esis of 11 a n d 12
F igu r e 4. Molecular structure of 9 (thermal ellipsoids at
30% probability). Hydrogen atoms have been removed for
clarity.
clusterization chemistry to nickel via complexation of
the alkyne substituent in 2a .31 When 2a was reacted
with bis(1,5-cyclooctadiene)nickel(0), [Ni(cod)2], in tolu-
ene, the methyl and phenyl resonances of 2a and the
olefinic resonances of cyclooctadienyl ligand shifted
downfield. This observation is consistent with the ad-
dition of a nickel moiety to the triple bond of the
phenylacetylene substituent of 2a to form 10 (Scheme
5, top). However, all attempts to separate the desired
product from unidentified side products were unsuc-
cessful, possibly due to subsequent dissociation of the
labile cod ligand. We postulated that replacement of the
cod ligand with a stronger donor, such as a bidentate
bisphosphine, should result in stabilization of the
complex. After the reaction of 2a with [Ni(cod)2], 1,2-
bis(dimethylphosphino)ethane (dmpe) or 1,2-bis(diphen-
ylphosphino)ethane (dppe) was added; this led to sub-
stitution of the cod ligand with dmpe or dppe and the
formation of 11 or 12, respectively (Scheme 5, bottom).
After workup and recrystallization from a mixture of
toluene and hexanes at -35 °C, we obtained 11 as a
red-orange solid (yield ) 61%). We isolated 12 as an
orange solid after workup (yield ) 56%).
The infrared spectrum of 9 showed three stretches at
1988, 1923, and 1837 cm-1, suggesting both terminal
and semibridging carbonyl ligands are present.27
To confirm the assigned structure, we performed a
single-crystal X-ray diffraction study for 9. Figure 4
shows the molecular structure of 9, and Table 5 lists
selected bond lengths and bond angles.
The X-ray study confirmed the identity of 9. The tilt
angle (20.93(20)°) and Fe-Si distance (2.7202(11) Å) in
9 are typical for sila[1]ferrocenophanes. Although the
tilt angle remained virtually unchanged (cf. 2a : R )
20.53(14)°) upon molybdenum coordination, the C(1)-
Si(1)-C(6) angle decreased from 96.50(13)° to 95.18(6)°.
Also, the Mo-Mo distance increased from 2.448(1) to
2.9625(4) Å, in agreement with other compounds con-
taining a Mo2C2 core. For example, the analogous
diphenylacetylene and diethylacetylene complexes have
Mo-Mo distances of 2.965(1) and 2.977(1) Å, respec-
tively.26 Bonding between the alkyne and the dimolyb-
denum unit can be described by the Dewar-Chatt-
Duncanson model:28,29 Acetylenic carbons became sp3-
like upon molybdenum coordination, with both sub-
stituents bending back from the C-C bond axis. The
acetylenic C-C bond length increased significantly from
1.197(4) to 1.366(5) Å, slightly longer than that of free
ethylene (d(CdC) ) 1.34 Å).30 The C(27)-C(28)-Si(1)
angle was 142.2(3)°, and the C(21)-C(27)-C(28) angle
was 136.4(3)°. As observed in previously characterized
[Cp2Mo2(CO)4(RCtCR′)] complexes,26 9 also contains a
semibridging carbonyl ligand (see Figure 4).
The 1H NMR spectrum of 11 contained three reso-
nances for phenyl protons at δ ) 8.13 (ortho), 7.28
(meta), and 7.10 (para) ppm and four resonances for Cp
protons at δ ) 4.47, 4.38, 4.29, and 4.15 ppm. A doublet
of triplets at δ ) 1.22 ppm was assigned to the four
methyl groups of dmpe. The four methylene protons
were found as a doublet at δ ) 1.13 ppm. The 13C{1H}
NMR spectrum of 11 contained two resonances for
acetylenic carbons at δ ) 159.1 and 158.8 ppm, ex-
tremely deshielded compared to those of 2a (δ ) 107.7
and 89.7 ppm).14 Nevertheless, downfield shifts of 40
to 55 ppm have been reported in the literature for [Ni-
(dippe)(RCtCR)] complexes (dippe ) bis(diisopropyl-
Syn th esis a n d Ch a r a cter iza tion of Sila [1]fer r o-
cen op h a n es w ith a P en d en t Or ga n on ick el Com -
p lex (11 a n d 12). We also attempted to expand the
(27) Le Berre-Cosquer, B.; Kergoat, R.; L’Haridon, P. Organome-
tallics 1992, 11, 721-728.
(28) Dewar, M. J . S. Bull. Soc. Chim. Fr. 1951, C71-79.
(29) Chatt, J .; Duncanson, L. A. J . Chem. Soc. 1953, 2939-2947.
(30) Elschenbroich, C.; Salzer, A. Organometallics: A Concise
Introduction; VCH Publishers Inc.: New York, 1992.
(31) We also attempted to complex the alkyne substituent using
[Fe2(CO)9]. However, 1H NMR (C6D6) analysis of the reaction mixture
in tetrahydrofuran (2 h, 25 °C) indicated a complex mixture of products.
This clusterization was not further pursued.

3802 Organometallics, Vol. 22, No. 19, 2003
Ta ble 6. Selected Bon d Len gth s (Å) a n d Bon d An gles (d eg) for 11
Chan et al.
Si(1)-C(1)
1.887(2)
1.888(2)
1.811(2)
1.288(3)
1.457(3)
1.905(2)
1.875(2)
Ni(1)-P(1)
2.1602(7)
2.1462(7)
2.7013(7)
96.07(10)
113.97(12)
154.67(19)
143.0(2)
C(12)-Ni(1)-C(13)
P(2)-Ni(1)-C(13)
P(1)-Ni(1)-P(2)
P(1)-Ni(1)-C(12)
R
39.84(10)
116.53(7)
90.13(3)
113.66(8)
19.90(13)
Si(1)-C(6)
Ni(1)-P(2)
Si(1)-C(12)
C(12)-C(13)
C(13)-C(14)
Ni(1)-C(12)
Ni(1)-C(13)
Fe(1)-Si(1)
C(1)-Si(1)-C(6)
C(11)-Si(1)-C(12)
Si(1)-C(12)-C(13)
C(12)-C(13)-C(14)
Ta ble 7. Selected Bon d Len gth s (Å) a n d Bon d An gles (d eg) for 12
Si(1)-C(1)
1.897(3)
1.889(2)
1.823(3)
1.284(3)
1.461(3)
1.904(2)
1.887(2)
Ni(1)-P(1)
2.1434(7)
2.1605(7)
2.7209(7)
95.13(10)
110.61(2)
153.9(2)
C(11)-Ni(1)-C(12)
P(1)-Ni(1)-C(12)
P(1)-Ni(1)-P(2)
P(2)-Ni(1)-C(11)
R
39.60(10)
116.81(8)
89.67(3)
113.68(8)
20.38(10)
Si(1)-C(6)
Ni(1)-P(2)
Si(1)-C(11)
C(11)-C(12)
C(12)-C(13)
Ni(1)-C(11)
Ni(1)-C(12)
Fe(1)-Si(1)
C(1)-Si(1)-C(6)
C(11)-Si(1)-C(19)
Si(1)-C(11)-C(12)
C(11)-C(12)-C(13)
141.5(2)
phosphino)ethane).32 The ipso-phenyl carbon of 11
resonated at δ ) 135.7 ppm, downfield to that of 2a (δ
) 123.0 ppm). The five resonances between δ ) 125-
132 ppm were assigned to the remaining phenyl carbons
and toluene molecules in the crystal lattice. The reso-
nance for ipso-Cp carbons at δ ) 37.6 ppm was also
significantly shifted downfield from that of 2a (δ ) 30.4
ppm).14 All of the carbons in the dmpe ligand coupled
to the phosphorus atoms: Methyl carbons gave four
doublets between δ ) 30.3 and 29.8 ppm, and methylene
carbons gave two doublet of doublets at δ ) 16.6 and
16.0 ppm. Unlike 1H resonances, 13C resonances indicate
the two ends of the dmpe ligand are inequivalent. The
29Si{1H} NMR spectrum of 11 contained a doublet of
doublets at δ ) 23.2 ppm, a result of coupling to two
inequivalent phosphorus atoms (3J SiP ) 16.5 and 11.9
Hz). The two strongly coupled resonances at δ ) 22.44
and 22.40 ppm in the 31P{1H} NMR spectrum of 11
support the assignment of two inequivalent phosphorus
atoms.
1
The H and 13C{1H} NMR spectra of 12 are similar
to those for 11, except P-Ph resonances are present
instead of P-Me signals. The methyl proton resonance
of 12 at δ ) 0.39 ppm is unusual in that it is shifted
upfield from that of 2a (δ ) 0.61 ppm), whereas all other
highly metallized sila[1]ferrocenophanes described in
this work exhibit downfield shifts.14 The ipso-Cp carbons
of 12 resonated at δ ) 36.7 ppm (4J CP ) 3.8 Hz), slightly
downfield to those of 2a (δ ) 30.4 ppm).14 The 29Si{1H}
NMR spectrum of 12 showed a doublet of doublets at δ
) 22.3 ppm (3J SiP ) 17.8, 8.7 Hz), indicative of coupling
to two inequivalent phosphorus atoms. The 31P{1H}
NMR spectrum of 12 contained two doublets at δ ) 52.9
and 51.7 ppm (2J PP ) 61 Hz).
We performed single-crystal X-ray diffraction studies
for 11 and 12 to confirm the assigned structures. Figure
5 shows the molecular structures of 11 and 12; Tables
6 and 7 list selected bond lengths and bond angles. The
X-ray studies confirmed the proposed structures of 11
and 12. The tilt angles in 11 (19.90(13)°) and 12
(20.38(10)°) were slightly smaller than that of 2a (R )
20.53(14)°).14 The C(1)-Si(1)-C(6) angles were
96.07(10)° in 11 and 95.13(10)° in 12, and the corre-
sponding Fe(1)-Si(1) distances were 2.7013(7) and
2.7209(7) Å, respectively. These parameters are similar
to those of 9. In both 11 and 12, the nickel atom had a
F igu r e 5. (a) Molecular structure of 11. (b) Molecular
structure of 12. For both structures, thermal ellipsoids are
displayed at 30% probability and hydrogen atoms have
been removed for clarity.
distorted square-planar geometry. Although the angles
around nickel summed to 360° (11: 360.16°; 12: 359.76°),
the C-Ni-C angle was much more acute than the
remaining angles. Nickel-carbon bond lengths in 11
and 12 ranged from 1.875 to 1.905 Å, similar to those
in [Ni(dmpe)(PhCtCPh)] (d(Ni-C) ) 1.876-1.879 Å).33
(32) Edelbach, B. L.; Lachicotte, R. J .; J ones, W. D. Organometallics
1999, 18, 4040-4049.
(33) Po¨rschke, K. R.; Mynott, R.; Angermund, K.; Kru¨ger, C. Z.
Naturforsch. 1985, 40b, 199-209.

Toward Highly Metallized Polymers
Organometallics, Vol. 22, No. 19, 2003 3803
Sch em e 6. In ser tion of P t(P Et3)2 in to
Sila [1]fer r ocen op h a n es 13 a n d 2a to F or m
P la tin a sila [2]fer r ocen op h a n es 14 a n d 15
F igu r e 6. Molecular structure of 15 (thermal ellipsoids
at 30% probability). Hydrogen atoms have been removed
for clarity.
6, bottom). After workup, we isolated red-orange crystals
of 15 by slowly evaporating a dichloromethane/hexanes
solution at 25 °C (yield ) 55%).
1
We used H, 13C, 29Si, 31P NMR, COSY, HSQC, and
CIGAR-HMBC20 spectroscopy to confirm the assigned
structure for 15, since the 1-D spectra were complex due
to the large number of NMR-active nuclei. The 1H NMR
spectrum of 15 clearly indicates loss of the strained sila-
[1]ferrocenophane structure. We observed eight reso-
nances for Cp protons between δ ) 5.01 and 4.11 ppm,
indicating that the two Cp rings are inequivalent. The
two multiplets at δ ) 2.20-2.08 and 1.99-1.89 ppm
were assigned to diastereotopic methylene protons of the
phosphine ligand cis to the chiral silicon atom. Meth-
ylene protons of the phosphine ligand trans to the silicon
atom were found at δ ) 1.26 ppm as a doublet of
quartets; these protons coupled to a phosphorus atom
(2J HP ) 7.2 Hz) and three neighboring methyl protons
(3J HH ) 7.2 Hz) with the same coupling constant. A
doublet at δ ) 1.12 ppm was assigned to the methyl
group bound to silicon; it showed coupling to phosphorus
(4J HP ) 2.1 Hz) and platinum satellites (3J HPt ) 13.9
Hz). The 13C{1H} NMR spectrum of 15 contained 10
resonances for Cp carbons between δ ) 80.7 and 69.0
ppm. The ipso-Cp carbon bound to silicon resonated at
δ ) 80.7 ppm, and the corresponding carbon bound to
platinum appeared as a doublet of doublets at δ ) 71.6
ppm (2J CP ) 99.9 and 13.3 Hz). These resonances shifted
significantly downfield from that of the ipso-Cp carbons
in 2a (δ ) 30.4 ppm),14 a result of the release of ring
strain in forming a [2]ferrocenophane. In the 29Si{1H}
NMR spectrum of 15, a doublet of doublets with
platinum satellites at δ ) -16.9 ppm (1J SiPt ) 1433 Hz,
2J SiP ) 208.8 and 18.3 Hz) indicated coupling of silicon
to the two phosphorus atoms. The 31P{1H} NMR spec-
trum of 15 contained two doublets with platinum
Acetylenic C-C bond lengths were 1.288(3) and
1.284(3) Å in 11 and 12, respectively, approaching that
of free ethylene (d(CdC) ) 1.34 Å).30 To the best of our
knowledge, 11 and 12 are the first examples of stable
mononuclear nickel alkyne complexes derived from
[Ni(cod)2] and an alkyne, as previous work has shown
that [Ni(cod)2] reacts with dialkyl- and diarylacetylenes
to form a dinuclear cluster, [Ni2(cod)2(RCtCR)].34 Ex-
amination of the molecular structures of 11 and 12
indicated that addition of a second nickel moiety to the
alkyne would probably be sterically unfavored. There-
fore, even when we reacted 2a with excess [Ni(cod)2],
only the mononuclear nickel complex was formed.
Rea ction of Acetylid e-Su bstitu ted Sila [1]fer r o-
cen op h a n e 2a w ith Tr is(tr ieth ylp h osp h in e)p la ti-
n u m (0): In ser tion of a P la tin u m (0) F r a gm en t in to
a n ipso-Cp Ca r bon -Silicon Bon d to for m a [2]-
F er r ocen op h a n e (15). Finally, to expand the cluster-
ization chemistry still further, we explored the possi-
bility of adding platinum(0) units via complexation of
the alkyne substituent in 2a . This is complicated by the
tendency of platinum(0) fragments to undergo oxidative
insertion into an ipso-Cp carbon-silicon bond of sila-
[1]ferrocenophanes: Previous work has shown that
[Pt(PEt3)3] reacts with sila[1]ferrocenophane 13 to give
the platinasila[2]ferrocenophane 14 (Scheme 6, top).35,36
Nevertheless, we wanted to explore if the reactivity of
[Pt(PEt3)3] would be changed by the presence of a
coordinating alkyne substituent. When a toluene solu-
tion of [Pt(PEt3)3] and 2a was stirred at 50 °C for 8 h,
only platinasila[2]ferrocenophane 15 was formed (Scheme
2
satellites at δ ) 12.2 (1J PPt ) 1137 Hz, J PP ) 20.0 Hz)
and 11.7 ppm (1J PPt ) 2132 Hz, 2J PP ) 20.0 Hz), showing
coupling between the two inequivalent phosphorus
atoms. To confirm the assigned structure of 15, we
performed a single-crystal X-ray diffraction study. Fig-
ure 6 shows the molecular structure of 15, and Table 8
lists selected bond lengths and bond angles.
(34) Muetterties, E. L.; Pretzer, W. R.; Thomas, M. G.; Beier, B. F.;
Thorn, D. L.; Day, V. W.; Anderson, A. B. J . Am. Chem. Soc. 1978,
100, 2090-2096.
(35) Sheridan, J . B.; Temple, K.; Lough, A. J .; Manners, I. J . Chem.
Soc., Dalton Trans. 1997, 711-713.
(36) (a) Sheridan, J . B.; Lough, A. J .; Manners, I. Organometallics
1996, 15, 2195-2197. (b) Reddy, N. P.; Choi, N.; Shimada, S.; Tanaka,
M. Chem. Lett. 1996, 649-650.

3804 Organometallics, Vol. 22, No. 19, 2003
Ta ble 8. Selected Bon d Len gth s (Å) a n d Bon d An gles (d eg) for 15
Chan et al.
Si(1)-C(1)
Si(1)-Pt(1)
Pt(1)-C(6)
Pt(1)-P(1)
Pt(1)-P(2)
Si(1)-C(11)
1.871(9)
2.378(2)
2.068(9)
2.291(2)
2.395(2)
1.874(9)
C(1)-Si(1)-C(11)
C(1)-Si(1)-C(19)
C(1)-Si(1)-Pt(1)
C(6)-Pt(1)-Si(1)
Si(1)-Pt(1)-P(1)
P(1)-Pt(1)-P(2)
102.4(4)
105.8(4)
116.5(3)
82.2(2)
92.60(8)
103.39(8)
P(2)-Pt(1)-C(6)
83.3(2)
177.8(8)
178.2(9)
9.36(64)
16.1(4)
6.5(3)
Si(1)-C(11)-C(12)
C(11)-C(12)-C(13)
R
âSi
âPt
All manipulations were performed under an atmosphere of
prepurified nitrogen using Schlenk techniques or in an inert
atmosphere glovebox. Solvents were dried using the Grubbs
method39 or standard methods followed by distillation. 1H (300
MHz), 13C (75.5 MHz), and 31P (121.5 MHz) NMR spectra were
recorded on a Varian Gemini 300 or Mercury 300 spectrometer.
1H (400 MHz), 13C (100.5 MHz), and 29Si (79.4 MHz) NMR
spectra were recorded on a Varian Unity 400 spectrometer.
1H (500 MHz), 13C (125.6 MHz), and 2-D NMR spectra were
The X-ray study confirmed the assigned structure of
15. The tilt angle of 9.36(64)° in 15 suggests it is less
strained than 14 (R ) 11.6(3)°).36 The angle between
the plane of the top Cp ring and the ipso-Cp carbon-
platinum bond (â) was 6.5(3)°, and the â angle between
the plane of the bottom Cp ring and the ipso-Cp carbon-
silicon bond was 16.1(4)°. A difference in â angles was
also observed in 14.36 The platinum atom in 15 had a
distorted square-planar geometry, with a larger than
ideal P(1)-Pt(1)-P(2) angle (103.39(8)°) and smaller
than ideal Si(1)-Pt(1)-C(6) and P(2)-Pt(1)-C(6) angles
(82.2(2)° and 83.3(2)°, respectively). The two platinum-
phosphorus bonds in 15 had almost the same length
(d(Pt-P) ) 2.291(2), 2.395(2) Å), similar to those in 14
(d(Pt-P) ) 2.2931(13), 2.4060(13) Å).36
1
recorded on a Varian Inova 500 spectrometer. H resonances
were referenced internally to the residual protonated solvent
resonances. 13C resonances were referenced internally to the
deuterated solvent resonances. 29Si and 31P resonances were
referenced externally to TMS and H3PO4 resonances, respec-
tively. Mass spectra were recorded with a VG 70-250S mass
spectrometer in electron impact (EI) mode. The calculated
isotopic distribution for each ion was in agreement with
experimental values. Infrared spectra were recorded using a
Perkin-Elmer Spectrum One FT-IR spectrometer. Ultraviolet-
visible spectra were recorded using a Perkin-Elmer Lambda
900 UV/VIS/NIR spectrometer. Elemental analyses were
performed using a Perkin-Elmer 2400 C/H/N analyzer.
Su m m a r y
We have described the synthesis of highly metallized
sila[1]ferrocenophanes containing cobalt, molybdenum,
or nickel units via direct reaction of an acetylide-
substituted sila[1]ferrocenophane with an appropriate
organometallic precursor.31 The nature of the product
depended on the metal: Cobalt and molybdenum gave
dinuclear clusters, while nickel gave mononuclear com-
plexes. The total number of metal clusters was also
controlled by varying the number of acetylenic substit-
uents in the sila[1]ferrocenophane.
The highly metallized sila[1]ferrocenophanes de-
scribed in this work displayed interesting structural
features and reactivity. Species 11 and 12 are the first
examples of stable mononuclear nickel complexes formed
from a disubstituted alkyne and [Ni(cod)2]: The usual
tendency to form a dinuclear cluster is presumably
greatly diminished due to steric crowding around the
alkyne. In the presence of trace amounts of moisture,
sila[1]ferrocenophanes 7a and 7b readily ring-opened
in solution to form silanols with intact cobalt clusters.
The synthesis of a sila[1]ferrocenophane with a pendent
organoplatinum unit remains a challenge, as the reac-
tion of 2a with [Pt(PEt3)3] yielded only a platinasila[2]-
ferrocenophane.
Syn th esis of 4a . [Co2(CO)8] (0.86 g, 2.5 mmol) in hexanes
(150 mL) was added dropwise to a stirred solution of 2a (0.75
g, 2.3 mmol) in hexanes (300 mL). The reaction mixture was
stirred at 25 °C for 2 h while vented through an oil bubbler to
release evolved CO. The flask was cooled to -55 °C, and 4a
precipitated as a red-purple microcrystalline solid, yield 0.92
g (65%). Crystals suitable for X-ray diffraction studies were
obtained from a dichloromethane/hexanes (1:1 v/v) solution at
-30 °C.
1
3
For 4a : H NMR (400 MHz, C6D6, 25 °C) δ ) 7.72 (d, J HH
3
) 7.2 Hz, 2 H, ortho-Ph), 7.02 (t, J HH ) 7.2 Hz, 2 H, meta-
Ph), 6.96 (d, J HH ) 7.2 Hz, 1 H, para-Ph), 4.36 (m, 2 H, Cp),
3
4.34 (m, 2 H, Cp), 4.25 (m, 2 H, Cp), 3.93 (m, 2 H, Cp) 0.73 (s,
3 H, Me); 13C{1H} NMR (100.5 MHz, C6D6, 25 °C) δ 200.1 (CO),
138.6 (ipso-Ph), 130.1, 129.3, 128.4 (Ph), 107.1 (SiCCPh), 78.6,
78.2, 76.0, 75.9 (Cp), 74.6 (SiCCPh), 33.6, (ipso-Cp), -1.9 (Me);
29Si{1H} NMR (79.4 MHz, C6D6, 25 °C) δ -11.8; MS (70 eV,
EI) m/z (%) 656 (24) [(2 × fcSiMe(CCPh))]+, 614 (2) [M]+, 328
(100) [fcSiMe(CCPh)]+, 286 (10) [(Co2(CO)6)]+, 186 (26) [fc]+;
HRMS (70 eV, EI) calcd for C25H16Co256FeO6Si 613.872952,
found 613.873412, fit 0.7 ppm; FT-IR (25 °C, hexanes) ν(CO)
2091 (m), 2055 (s), 2030 (s), 2013 (w) cm-1; UV-vis (25 °C,
THF) λmax ) 443 nm, ꢀ ) 2.2 × 103 L‚mol-1‚cm-1, abs > 0 until
ca. 700 nm.
We are currently exploring the ROP behavior of these
highly metallized sila[1]ferrocenophanes as well as the
properties and applications of the resulting polymers.
The results of these detailed studies will be subjects of
future publications.15
Syn th esis of 4b. [Co2(CO)8] (1.15 g, 3.4 mmol) in hexanes
(200 mL) was added to a stirred solution of 2b (1.04 g, 3.4
mmol) in hexanes (100 mL). The reaction mixture was stirred
at 25 °C for 1 h while vented through an oil bubbler to release
evolved CO, and all volatile materials were removed in vacuo.
The residue was taken up in hexanes and filtered through
glass wool to remove small amounts of insoluble impurities.
Dark red-purple crystals of 4b were obtained at -55 °C, yield
1.61 g (80%). Crystals suitable for X-ray diffraction studies
were obtained from a hexanes solution at -30 °C.
Exp er im en ta l Section
[Ni(cod)2], dmpe, and dppe were purchased from Aldrich and
used as received. [Co2(CO)8] and [{MoCp(CO)3}2] were pur-
chased from STREM; [Co2(CO)8] was sublimed immediately
before use. Reactions involving [Co2(CO)8] require ambient
light to proceed. Compounds 2a ,14 2b,14 6b,14 [{MoCp(CO)2}2],37
and [Pt(PEt3)4]38 were synthesized according to literature
procedures.
For 4b: 1H NMR (400 MHz, C6D6, 25 °C) δ 4.46 (m, 2 H,
Cp), 4.37 (m, 2 H, Cp), 4.23 (m, 2 H, Cp), 3.92 (m, 2 H, Cp),
2.96 (m, 2 H, CH2CH2CH2CH3), 1.76 (m, 2 H, CH2CH2CH2-
(38) Yoshida, T.; Matsuda, T.; Otsuka, S. Inorg. Synth. 1990, 28,
122-123.
(39) Pangborn, A. B.; Giardello, M. A.; Grubbs, R. H.; Rosen, R. K.;
Timmers, F. J . Organometallics 1996, 15, 1518-1520.
(37) Ginley, D. S.; Bock, C. R.; Wrighton, M. S. Inorg. Chim. Acta
1997, 23, 85-94.

Toward Highly Metallized Polymers
Organometallics, Vol. 22, No. 19, 2003 3805
3
CH3), 1.28 (m, 2 H, CH2CH2CH2CH3), 0.84 (t, 3 H, J HH ) 7.2
Hz, CH2CH2CH2CH3), 0.72 (s, 3 H, SiCH3); 13C{1H} NMR
(100.5 MHz, C6D6, 25 °C) δ 200.6 (CO), 113.1 (SiCCPh), 72.5
(SiCCPh) 78.4, 78.1, 75.8, 75.7 (Cp), 34.9 (CH2CH2CH2CH3),
34.8 (CH2CH2CH2CH3), 34.2 (ipso-Cp), 22.9 (CH2CH2CH2CH3),
13.9 (CH2CH2CH2CH3), -2.7 (SiCH3); 29Si{1H} NMR (79.4
MHz, C6D6, 25 °C) δ -12.5; MS (70 eV, EI) m/z (%) 594 (34)
[M]+, 538 (62) [M - 2 CO]+, 510 (53) [M - 3 CO]+, 482 (69) [M
- 4 CO]+, 308 (100) [M - Co2(CO)6]+ ; HRMS (70 eV, EI) calcd
for C23H20Co256FeO6Si 593.904252, found 593.902933, fit 2.2
ppm; FT-IR (25 °C, hexanes) ν(CO) 2089 (m), 2051 (s), 2021
(s) cm-1. Anal. Calcd for C23H20Co2FeO6Si: C 46.49, H 3.39.
Found: C 46.24, H 3.29.
2.49 (s, SiOH), 1.75 (m, CH2CH2CH2CH3), 1.34 (m, CH2CH2CH2-
CH3), 0.89 (m, CH3).
Attem p ted Syn th esis of 7b; Un exp ected F or m a tion of
8b. [Co2(CO)8] (253 mg, 0.74 mmol) in hexanes (10 mL) was
added dropwise to a stirred solution of 6b (100 mg, 0.24 mmol)
in hexanes (10 mL). The solution was stirred at 25 °C for 2 h
while vented to an oil bubbler to release evolved CO. All
volatile material was removed in vacuo to give a dark brown
residue. This was dissolved in ether, and the solution was
allowed to evaporate at 25 °C. Silanol 8b was formed as the
sole product after three weeks. Crystals suitable for X-ray
diffraction studies were obtained from a hexanes/CH2Cl2 (3:1
v/v) solution at -35 °C.
Syn th esis of 6a . This compound was synthesized using a
procedure analogous to that for the phenylacetylide-substi-
tuted analogue (6b).14 Yield: 83% (crude, >95% pure).
For 6a : 1H NMR (500 MHz, C6D6, 25 °C) δ 4.48 (m, 4 H,
For 7b: 1H NMR (400 MHz, C6D6, 25 °C) δ 7.63-7.60 (m, 4
H, ortho-Ph), 6.92-6.89 (m, 6 H, meta-, para-Ph), 4.59 (m, 4
H, Cp), 4.42 (m,4 H, Cp); 13C{1H} NMR (100.5 MHz, C6D6, 25
°C) δ 200.3 (CO), 138.7 (ipso-Ph), 130.7, 129.1 (Ph), 78.8, 76.3
3
(Cp), 34.0 (ipso-Cp).
Cp), 4.42 (m, 4 H, Cp), 2.01 (t, J HH ) 7.0 Hz, 4 H, CH2CH2-
3
For 8b: 1H NMR (400 MHz, C6D6, 25 °C) δ 7.75 (d, J HH
)
3
CH2CH3), 1.29 (m, 8 H, CH2CH2CH2CH3), 0.73 (t, J HH ) 7.0
7.6 Hz, 4 H, ortho-Ph), 7.06 (dd, 3J HH ) 7.6, 7.6 Hz, 4 H, meta-
Hz, 6 H, CH3); 13C{1H} NMR (100.5 MHz, C6D6, 25 °C) δ 110.5
(SiCCBu), 78.28(Cp), 78.24 (SiCCBu), 30.4 (CH2CH2CH2CH3),
29.6 (ipso-Cp), 22.1 (CH2CH2CH2CH3), 19.8 (CH2CH2CH2CH3),
13.6 (CH3); 29Si{1H} NMR (79.4 MHz, C6D6, 25 °C) δ -56.0;
MS (70 eV, EI) m/z (%) 374 (100) [M]+; HRMS (70 eV, EI) calcd
for C22H2656FeSi 374.115319, found 374.115293, fit 0.1 ppm.
Syn th esis of 7a . [Co2(CO)8] (413 mg, 1.2 mmol) in hexanes
(5 mL) was added portionwise to a stirred solution of 6a (152
mg, 0.41 mmol) in hexanes (5 mL). The reaction mixture was
stirred at 25 °C for 1 h while vented through an oil bubbler to
release evolved CO. All volatile materials were removed in
vacuo to give a dark brown solid. Recrystallization from
hexanes at -35 °C gave dark brown crystals from which a
small amount of [Co4(CO)12] was removed by sublimation, yield
243 mg, 63%. Crystals suitable for X-ray diffraction studies
were obtained from the same sublimation.
3
Ph), 6.96 (dd, J HH ) 7.6, 7.6 Hz, 2 H, para-Ph), 4.57 (m, 2 H,
Cp), 4.24 (m, 2 H, Cp), 4.05, (s, 5 H, free Cp), 2.84 (s, 1 H,
SiOH); 13C{1H} NMR (100.5 MHz, C6D6, 25 °C) δ 200.0 (CO),
138.2, 130.5, 129.2, 128.6 (Ph), 106.5 (SiCCPh), 74.7, 72.6, 71.8,
69.6, 69.1 (Cp); 29Si{1H} NMR (79.4 MHz, C6D6, 25 °C) δ -13.4;
MS analysis was not possible due to the low volatility of 8b;
FT-IR (25 °C, hexanes) ν(CO) 2087 (m), 2054 (s), 2026 (s), 2009
(w) cm-1. Anal. Calcd for C38H20Co4FeO13Si: C 45.45, H 2.01.
Found: C 45.39, H 1.91.
Syn th esis of 9. 2a (204 mg, 0.62 mmol) and [{MoCp(CO)2}2]
(274 mg, 0.63 mmol) were dissolved in toluene (20 mL), and
the dark red solution was stirred at 75 °C for 21.5 h. After
cooling to 25 °C, all volatile materials were removed in vacuo.
The residue was recrystallized from hexanes/dichloromethane
(7:6 v/v) at -35 °C to give dark red-purple crystals of 9, yield
181 mg (38%). Crystals suitable for X-ray diffraction studies
For 7a : 1H NMR (500 MHz, C6D6, 25 °C) δ 4.54 (m, 4 H,
3
were obtained by slow evaporation of an ethereal solution.
Cp), 4.51 (m, 4 H, Cp), 3.15 (t, J HH ) 8.5 Hz, 4 H, CH2CH2-
3
For 9: 1H NMR (300 MHz, C6D6, 25 °C) δ 7.67 (d, J HH
)
3
CH2CH3), 1.84 (pentet, J HH ) 8.0 Hz, 4 H, CH2CH2CH2CH3),
1.35 (sextet, 3J HH ) 7.0 Hz, 4 H, CH2CH2CH2CH3), 0.89 (t, 3J HH
) 7.5 Hz, 6 H, CH3); 13C{1H} NMR (75.5 MHz, C6D6, 25 °C) δ
200.7 (CO), 115.1 (SiCCBu), 78.9, 76.5 (Cp), 70.2 (SiCCBu),
35.7 CH2CH2CH2CH3), 35.0 (CH2CH2CH2CH3), 34.6 (ipso-Cp),
23.1 (CH2CH2CH2CH3), 14.1 (CH3); 29Si{1H} NMR (79.4 MHz,
C6D6, 25 °C) δ -18.4; MS analysis was not possible as the
sample decomposed in the spectrometer; also, the molecular
weight of this compound is too high for HRMS; FT-IR (25 °C,
hexanes) ν(CO) 2084 (m), 2056 (s), 2026 (s, contains a shoulder)
cm-1. Anal. Calcd for C34H26Co4FeO12Si: C 43.16, H 2.77.
Found: C 35.65, H 2.68. We attribute the low carbon value to
the presence of a trace amount of [Co4(CO)12]. A band corre-
sponding to [Co4(CO)12] was observed in the infrared spectrum
at 1867 cm-1; the intensity of this band is about 3% of that at
2026 cm-1 ([Co4(CO)12] shows two CO stretches at 1900 and
1867 cm-1 in the bridging region, see ref 40). Despite subliming
the sample at room temperature for 2 days, we were unable
to completely remove [Co4(CO)12]. We were also unable to
separate [Co4(CO)12] from 7a by recrystallization, as both
compounds are soluble in hexanes.
F or m a tion of 8a fr om th e Hyd r olytic Rin g-Op en in g
of 7a . A deuterated benzene solution of crude 7a showed new
1H resonances after standing 1 day at 25 °C (ca. 30% conver-
sion). The new resonances have chemical shifts very similar
to those of 8b. By analogy, the new compound was assigned
as 8a .
For 8a (only partial data are given, as the solution contained
a mixture of 7a and 8a , making it difficult to obtain accurate
integral values.): 1H NMR (500 MHz, C6D6, 25 °C) δ 4.38 (m,
Cp), 4.21 (m, Cp), 4.05 (s, free Cp), 3.01 (m, CH2CH2CH2CH3),
7.6 Hz, 2 H, ortho-Ph), 7.18-7.12 (m, 2 H, meta-Ph), 6.92 (t,
3J HH ) 7.6 Hz, 1 H, para-Ph), 4.99 (br s, 10 H, CpMo), 4.51-
4.49 (m, 2 H, CpFe), 4.41-4.39 (m, 2 H, CpFe), 4.33 (br s, 2 H,
CpFe), 4.03-4.02 (m, 2 H, CpFe), 0.68 (s, 3 H, Me); 13C{1H} NMR
(125.6 MHz, C6D6, 25 °C) δ 233, 230.5 (CO), 147.9 (ipso-Ph),
130.8, 128.3, 126.2 (Ph), 92.2 (CpMo), 78.0, 77.6, 76.2, 76.1
(CpFe), 37.8 (ipso-Cp), -1.7 (Me); 29Si{1H} DEPT NMR (79.4
MHz, C6D6, 25 °C) δ -3.8; MS (70 eV, EI) m/z (%) 552 (1) [M
- 2Cp - 3CO]+, 524 (14) [M - 2Cp - 4CO]+, 432 (19) [M -
2Cp - 4CO - Mo]+; FT-IR (25 °C, CH2Cl2) ν(CO) 1988 (m),
1923 (s), 1837 (w) cm-1. Anal. Calcd for C33H26FeMo2O4Si: C
51.99, H 3.44. Found: C 51.54, H 3.46.
Attem p ted Syn th esis of 10. In the absence of light,
[Ni(cod)2] (84 mg, 0.31 mmol) was added to a stirred solution
of 2a (101 mg, 0.31 mmol) in toluene (5 mL). The mixture was
stirred at 25 °C for 15 min, and all volatile material was
removed in vacuo. Recrystallization from hexane/toluene (4:1
v/v) at -35 °C failed to remove the unidentified side products.
For 10: 1H NMR (300 MHz, C6D6, 25 °C) δ 7.78-7.74 (m, 2
H, ortho-Ph), 7.17-7.12 (m, 2 H, meta-Ph), 7.08-7.04 (m, 1
H, para-Ph), 5.95 (s, 2 H, cod), 5.50 (s, 2 H, cod), 4.44, 4.41,
4.26, 4.08 (m, 8 H, Cp), 2.18-2.02 (m, 4 H, cod), 1.98-1.84
(m, 4H, cod), 0.67 (s, 3 H, Me).
Syn th esis of 11. In the absence of light, [Ni(cod)2] (136 mg,
0.49 mmol) was added to a stirred solution of 2a (160 mg, 0.49
mmol) in toluene (14 mL). The mixture was stirred at 25 °C
for 10 min, and a solution of dmpe (73 mg, 0.49 mmol) in
toluene (2 mL) was added. After 30 min, all volatile materials
were removed in vacuo to give an orange solid. Recrystalliza-
tion from toluene/hexanes (2:1 v/v) at -35 °C gave red-orange
crystals, yield 175 mg, 61%. Crystals suitable for X-ray
diffraction studies were obtained from the same recrystalli-
zation.
(40) Darensbourg, D. J .; Incorvia, M. J . Inorg. Chem. 1980, 19,
2585-2590.

3806 Organometallics, Vol. 22, No. 19, 2003
Chan et al.
Ta ble 9. Selected Cr ysta l, Da ta Collection , a n d Refin em en t P a r a m eter s for 4a , 4b a n d 7a
4a
4b
7a
formula
Mr
C
25H16Co2FeO6Si
C23H20Co2FeO6Si
594.19
C34H26Co4FeO12Si
946.21
614.18
cryst syst
space group
a, Å
b, Å
c, Å
R, deg
â, deg
γ, deg
V, Å3
triclinic
P1h
8.2617(4)
8.3552(17)
18.4860(7)
99.881(3)
100.468(3)
101.146(2)
1202.6(3)
monoclinic
P21/c
14.3173(4)
11.5858(3)
15.4520(5)
90
111.1340(10)
90
2390.74(12)
4
1.651
2.057
triclinic
P1h
11.6454(3)
12.5364(4)
13.7397(5)
83.3740(10)
75.3260(10)
70.852(2)
1831.95(10)
2
Z
F
2
calc, g cm-3
1.696
2.048
616
1.715
2.253
948
µ(Mo KR), mm-1
F(000)
1200
cryst size, mm3
θ range, deg
0.15 × 0.13 × 0.07
2.56-27.50
26 617
5498 (Rint ) 0.039)
semiempirical from equivalents
0.8699 and 0.7487
328
1.138
0.0465
0.1094
0.545 and -0.633
0.24 × 0.10 × 0.06
0.24 × 0.12 × 0.08
2.70-27.56
25 842
8400 (Rint ) 0.0712)
semiempirical from equivalents
0.678 and 0.614
470
1.001
0.0397
0.0885
2.83-25.01
no. of reflns collected
no. of indep reflns
abs corr
14 450
4201 (Rint ) 0.081)
semiempirical from equivalents
0.8865 and 0.6381
301
0.986
0.0411
max. and min. transmn coeff
no. of params refined
GoF on F2
R1a (I>2σ(I))
wR2b (all data)
peak and hole, e Å-3
0.0916
0.384 and -0.364
0.502 and -0.636
R1 ) ∑||Fo| - |Fo||/∑|Fo|. wR2 ) {∑[w(Fo - Fc2)2]/∑[w(Fo2)2]}1/2
.
a
b
2
3
For 11: 1H NMR (300 MHz, C6D6, 25 °C) δ 8.13 (d, J HH
)
4J CP ) 13.8 Hz, para-Ph of dppe), 128.7 (d, 3J CP ) 9.1 Hz, meta-
3
3
7.5 Hz, 2 H, ortho-Ph), 7.28 (t, J HH ) 7.5 Hz, 2 H, meta-Ph),
Ph of dppe), 128.5 (d, J CP ) 8.3 Hz, meta-Ph of dppe), 128.3,
3
4
7.10 (t, J HH ) 7.5 Hz, 1 H, para-Ph), 4.47 (m, 2 H, Cp), 4.38
126.6 (Ph), 77.2 (Cp × 2), 77.0, 75.1 (Cp), 36.7 (d, J CP ) 3.8
1
2
(m, 2 H, Cp), 4.29 (m, 2 H, Cp), 4.15 (m, 2 H, Cp), 1.22 (dt,
Hz, ipso-Cp), 29.4 (dd, J CP ) 19.1 Hz, J CP ) 15.3 Hz, CH2),
1 2
2J HP ) 40.8 Hz, J HH ) 3.0 Hz, 12 H, CH3 of dmpe), 1.13 (d,
29.0 (dd, J CP ) 19.1 Hz, J CP ) 15.3 Hz, CH2), -2.9 (SiCH3);
29Si{1H} DEPT NMR (79.4 MHz, C6D6, 25 °C) δ 22.3 (dd, 3J SiP
) 17.8, 8.7 Hz); 31P{1H} NMR (121.5 MHz, C6D6, 25 °C) δ 52.9
(d, J PP ) 61 Hz), 51.7 (d, J PP ) 61 Hz); MS analysis was not
possible, as the sample decomposed in the spectrometer. Anal.
Calcd for C45H40FeNiP2Si: C 68.81, H 5.13. Found: C 69.11,
H 5.48.
4
2J HP ) 12.8 Hz, 4 H, CH2), 0.74 (s, 3 H, SiCH3); 13C{1H} NMR
(100.5 MHz, C6D6, 25 °C) δ 159.1, 158.8 (m, SiCCPh), 135.7
(ipso-Ph), 131.3 (Ph), 129.3 (toluene in lattice), 128.5 (Ph,
toluene in lattice), 126.7 (Ph), 125.6 (toluene in lattice), 77.42,
2
2
1
77.36, 77.2, 75.3 (Cp), 37.6 (ipso-Cp), 30.3 (d, J CP ) 21.3 Hz,
1
CH3 of dmpe), 30.1 (d, J CP ) 21.3 Hz, CH3 of dmpe), 30.0 (d,
1J CP ) 21.4 Hz, CH3 of dmpe), 29.8 (d, J CP ) 21.4 Hz, CH3 of
Syn th esis of 15. [Pt(PEt3)4] (204 mg, 0.31 mmol) was
heated under high vacuum at 60 °C until conversion of the
white powder into an orange oil, [Pt(PEt3)3], was complete (ca.
30 min). Toluene (25 mL) was added to [Pt(PEt3)3], and a
solution of 1a (100 mg, 0.30 mmol) in toluene (15 mL) was
added dropwise with stirring. The reaction mixture was stirred
at 50 °C for 8 h. All volatile materials were removed in vacuo,
and the orange-red solid was taken up in a minimal amount
of hexanes/dichloromethane (1:1 v/v). Crystals of 15 were
obtained by slow evaporation of this solution, yield 125 mg
(55%). Crystals suitable for X-ray crystallography studies were
obtained using the same method.
1
1
2
dmpe), 21.4 (toluene in lattice), 16.6 (dd, J CP ) 12.3 Hz, J CP
1
2
) 9.1 Hz, CH2), 16.0 (dd, J CP ) 13.8 Hz, J CP ) 9.1 Hz, CH2),
-2.1 (SiCH3); 29Si{1H} DEPT NMR (79.4 MHz, C6D6, 25 °C) δ
23.2 (dd, J SiP ) 16.5, 11.9 Hz); 31P{1H} NMR (121.5 MHz,
3
C6D6, 25 °C) δ 22.44, 22.40 (2nd order spectrum); MS analysis
was not possible, as the sample decomposed in the spectrom-
eter. Anal. Calcd for C28.5H36FeNiP2Si: C 58.70, H 6.22.
Found: C 58.77, H 6.07.
Syn th esis of 12. In the absence of light, 2a (151 mg, 0.46
mmol) was dissolved in toluene (15 mL) to give a red solution.
[Ni(cod)2] (126 mg, 0.46 mmol) was added, and the red solution
darkened within 1 min. It was stirred at 25 °C for 10 min,
and dppe (181 mg, 0.46 mmol) was added. After 30 min, all
volatile materials were removed in vacuo. The residue was
washed twice with hexanes to give an orange solid 12, yield
203 mg (56%). Crystals suitable for X-ray diffraction studies
were obtained from a dichloromethane/hexanes (1:1 v/v) solu-
For 15: 1H NMR (500 MHz, C6D6, 25 °C) δ 7.51-7.48 (m, 2
H, ortho-Ph), 7.03-7.00 (m, 2 H, meta-Ph), 6.98-6.95 (m, 1
H, para-Ph), 5.01, 4.85 (m, 2 H, R-CpSi), 4.55 (m, 1 H, â-CpPt),
4.49 (m, 1 H, â-CpSi), 4.42 (m, 1 H, â-CpPt), 4.29 (m, 1 H,
â-CpSi), 4.16, 4.11 (m, 2 H, R-CpPt), 2.20-2.08 (m, 3 H,
P(CHHCH3)3), 1.99-1.89 (m, 3 H, P(CHHCH3)3), 1.26 (dq, 3J HH
2
3
tion at -35 °C.
) 7.2 Hz, J HP ) 7.2 Hz, 6 H, P(CH2CH3)3), 1.12 (d, J HPt )
4 3 3
3
For 12: 1H NMR (400 MHz, C6D6, 25 °C) δ 7.95 (d, J HH
)
13.9 Hz, J HP ) 2.1 Hz, SiCH3), 0.97 (dt, J HP ) 15.3 Hz, J HH
3 3
8.4 Hz, 2 H, ortho-Ph), 7.81-7.77 (m, 4 H, Ph and Phdppe),
7.74-7.68 (m, 4 H, Phdppe), 7.04-6.92 (m, 15 H, Phdppe), 4.38
(m, 2 H, Cp), 4.33 (m, 2 H, Cp), 4.31 (m, 2 H, Cp), 3.98 (m, 2
H, Cp), 2.10-1.98 (m, 4 H, CH2), 0.39 (s, 3 H, Me); 13C{1H}
) 7.8 Hz, 9 H, P(CHHCH3)3), 0.77 (dt, J HP ) 14.7 Hz, J HH )
7.5 Hz, 9 H, P(CH2CH3)3); 13C{1H} NMR (125.6 MHz, C6D6,
25 °C) δ 131.4 (ortho-Ph × 2), 128.3 (meta-Ph × 2), 127.4 (para-
2
3
Ph), 125.8 (ipso-Ph), 107.5 (dd, J CPt ) 88 Hz, J CP ) 18.2, 3.5
Hz, SiCCPh), 106.3 (d, 3J CPt ) 31 Hz, 4J CP ) 4.7 Hz, SiCCPh),
2
NMR (100.5 MHz, C6D6, 25 °C) δ 158.6 (d, J CP ) 6.6 Hz,
2
1
2
SiCCPh), 158.2 (d, J CP ) 5.3 Hz, SiCCPh), 136.6 (dd, J CP
)
80.7 (m, ipso-CpSi), 75.9, 75.6 (R-CpSi), 75.2 (d, J CPt ) 64 Hz,
27.4 Hz, 3J CP ) 6.1 Hz, ipso-Ph of dppe), 136.3 (dd, 1J CP ) 28.2
Hz, 3J CP ) 6.1 Hz, ipso-Ph of dppe), 135.7 (dd, 3J CP ) 11.5, 5.3
Hz, ipso-Ph), 133.8 (d, 2J CP ) 13.8 Hz, ortho-Ph of dppe), 133.3
3J PC ) 6.0 Hz, R-CpPt), 73.5 (dd, J CPt ) 46 Hz, J CP ) 5.0, 3.3
2
3
2
Hz, R-CpPt), 71.9 (â-CpSi), 71.6 (dd, J CP ) 99.9, 13.3 Hz, ipso-
3
4
CpPt), 71.5 (d, J CPt ) 52 Hz, J CP ) 6.0 Hz, â-CpPt), 69.7 (d,
2
4
4
(d, J CP ) 13.7 Hz, ortho-Ph of dppe), 131.2 (d, J CP ) 3.8 Hz,
ortho-Ph), 129.6 (d, J CP ) 1.5 Hz, para-Ph of dppe), 129.5 (d,
3J CPt ) 50 Hz, J CP ) 5.5 Hz, â-CpPt), 69.0 (â-CpSi), 17.7 (dd,
4
1
3
2J CPt ) 26 Hz, J CP ) 28.3 Hz, J CP ) 4.3 Hz, P(CHHCH3)3),

Toward Highly Metallized Polymers
Organometallics, Vol. 22, No. 19, 2003 3807
Ta ble 10. Selected Cr ysta l, Da ta Collection , a n d Refin em en t P a r a m eter s for 8b, 9 a n d 11
8b
9
11
formula
Mr
C
38H20Co4FeO13Si
C33H26FeMo2O4Si
762.36
C25H32FeNiP2Si‚0.5C7H8
583.16
1004.20
cryst syst
space group
a, Å
b, Å
c, Å
R, deg
â, deg
γ, deg
V, Å3
triclinic
P1h
triclinic
P1h
triclinic
P1h
10.3489(2)
11.1236(3)
16.7606(4)
85.3030(10)
86.2970(10)
85.2870(10)
1913.19(8)
2
8.6700(2)
9.9580(2)
18.3510(6)
76.2870(12)
89.0310(12)
67.6720(13)
1419.06(6)
2
10.6560(2)
12.0500(2)
12.6570(3)
62.6990(8)
87.3300(8)
77.0250(8)
1404.32(5)
2
Z
F
calc, g cm-3
1.743
2.165
1000
1.784
1.455
760
1.379
1.359
610
µ(Mo KR), mm-1
F(000)
cryst size, mm3
θ range, deg
0.40 × 0.35 × 0.35
2.60-27.50
27 530
8779 (Rint ) 0.0407)
semiempirical from
equivalents
0.5178 and 0.4780
518
1.017
0.0343
0.0876
1.792 and -0.717
0.20 × 0.06 × 0.03
2.80-27.50
16 977
6474 (Rint ) 0.0542)
semiempirical from
equivalents
0.958 and 0.912
371
1.038
0.0373
0.0869
0.750 and -0.810
0.30 × 0.20 × 0.14
2.59-27.56
20 633
6446 (Rint ) 0.0488)
semiempirical from
equivalents
0.831 and 0.767
296
1.079
0.0382
0.1059
0.375 and -0.507
no. of reflns collected
no. of indep reflns
abs corr
max. and min. transmn coeff
no. of params refined
GoF on F2
R1a (I>2σ(I))
wR2b (all data)
peak and hole, e Å-3
R1 ) ∑||Fo| - |Fo||/∑|Fo|. wR2 ) {∑[w(Fo - Fc2)2]/∑[w(Fo2)2]}1/2
.
a
b
2
Ta ble 11. Selected Cr ysta l, Da ta Collection , a n d Refin em en t P a r a m eter s for 12 a n d 15
12 15
45H40FeNiP2Si C31H46FeP2PtSi
formula
Mr
C
785.36
759.65
cryst syst
space group
a, Å
b, Å
c, Å
R, deg
â, deg
γ, deg
V, Å3
triclinic
P1h
monoclinic
P21/n
10.3650(3)
20.3410(7)
15.1410(6)
90
90.7320(18)
90
3191.98(19)
4
1.581
4.988
11.5830(3)
12.0940(3)
14.8820(4)
108.2460(11)
92.8720(12)
106.6890(8)
1873.92(8)
2
Z
F
calc, g cm-3
1.392
1.039
816
µ(Mo KR), mm-1
F(000)
1520
cryst size, mm3
θ range, deg
0.30 × 0.20 × 0.18
0.18 × 0.10 × 0.08
2.74-27.56
2.57-26.46
no. of reflns collected
no. of indep reflns
abs corr
29 460
27 986
8623 (Rint ) 0.0679)
semiempirical from equivalents
0.766 and 0.665
453
1.033
0.0405
6548 (Rint ) 0.0878)
semiempirical from equivalents
0.6910 and 0.4671
327
1.061
0.0507
max. and min. transmn coeff
no. of params refined
GoF on F2
R1a (I>2σ(I))
wR2b (all data)
peak and hole, e Å-3
0.1077
0.444 and -0.691
0.1214
2.027 and -1.823
a
b
2
R1 ) ∑||Fo| - |Fo||/∑|Fo|. wR2 ) {∑[w(Fo - Fc2)2]/∑[w(Fo2)2]}1/2
.
15.9 (d, J CPt ) 15 Hz, J CP ) 19.2 Hz, P(CH2CH3)3), 8.8 (3J CPt
Kappa-CCD diffractometer and monochromated Mo KR radia-
tion (λ ) 0.71073 Å). The data were integrated and scaled
using the Denzo-SMN package.41 The SHELXTL/PC package
was used to solve and refine the structures.42 Refinement was
by full-matrix least-squares on F2 using all data (negative
intensities included). Hydrogen atoms were placed in calcu-
lated positions and included in the refinement in riding motion
approximations.
2
1
) 22 Hz, P(CHHCH3)3), 8.1 (3J CPt ) 14 Hz, P(CH2CH3)3), 4.5
(d, J CPt ) 67 Hz, J CP ) 6.0 Hz, CH3); 29Si{1H} DEPT NMR
2
3
(79.4 MHz, C6D6, 25 °C) δ -16.9 (1J SiPt ) 1433 Hz, J SiP
)
2
208.8, 18.3 Hz); 31P{1H} NMR (121.5 MHz, C6D6, 25 °C) δ 12.2
(1J PPt ) 1137 Hz, J PP ) 20.0 Hz), 11.7 (1J PPt ) 2132 Hz, J PP
) 20.0 Hz). Anal. Calcd for C31H46FeP2PtSi2: C 49.01, H 6.12.
Found: C 49.17, H 6.20.
2
2
X-r a y Cr ysta llogr a p h y. Selected crystal, data collection,
and refinement parameters for 4a , 4b, 7a , 8b, 9, 11, 12, and
15 are given in Tables 9, 10, and 11. Selected bond lengths
and bond angles are given in Tables 1 (4a ), 2 (4b), 3 (7a ), 4
(8b), 5 (9), 6 (11), 7 (12), and 8 (15). Single-crystal X-ray
diffraction data were collected at 150(1) K using a Nonius
The entire molecule of 4a is disordered over two sites with
occupancies 0.98/0.02. This was indicated by two large peaks
(41) Otwinowski, Z.; Minor, W. Methods Enzymol. 1997, 276, 307-
326.
(42) Sheldrick, G. M. SHELXTL/ PC V5.1; Bruker Analytical X-ray
Systems: Madison, WI, 1997.

3808 Organometallics, Vol. 22, No. 19, 2003
Chan et al.
in the final difference Fourier map that had the same distance
between them as Co(1) and Co(2). As a result, the cobalt atoms
are refined with partial occupancies; the rest of the atoms are
refined with full occupancy.
m.ac.uk/conts/retrieving.html (or from the Cambridge
Crystallographic Data Centre, 12 Union Road, Cambridge
CB2 1EZ, UK; fax: (+44) 1223-336-033; or e-mail: deposit@
ccdc.cam.ac.uk).
The -CH2-CH2- backbone of the dmpe ligand in 10 is
disordered over two sites with occupancies 0.81/0.19. Also, a
difference Fourier map at an intermediate stage in the
refinement revealed a volume of electron density that was
associated with a severely disordered toluene molecule with
0.5 occupancy. The electron count contribution of this disor-
dered solvent molecule was removed from the Fourier syn-
thesis using the program SQUEEZE in PLATON.43 Least-
squares cycles run before and after this procedure showed no
effect on the bond lengths and bond angles of the main
molecule. The half molecule of toluene is included in the
empirical formula.
Ack n ow led gm en t. We wish to acknowledge an
NSERC postgraduate scholarship for W.Y.C. and A.B.
and a PDF Scholarship for S.B.C.. I.M. is grateful to
the NSERC Discovery Grants program for funding the
research and to the University of Toronto for a McLean
Fellowship (1997-2003), the Ontario Government for
a PREA Award (1999-2003), and the Canadian Gov-
ernment for a Canada Research Chair. We also wish to
thank Cory J aska for supplying [Pt(PEt3)4] and Dr.
Timothy Burrow for collecting 2-D NMR data.
CCDC-190309 (4a ), CCDC-216383 (4b), CCDC-216378 (7a ),
CCDC-216382 (8b), CCDC-216379 (9), CCDC-216384 (11),
CCDC-216381 (12), and CCDC-216380 (15) contain the supple-
mentary crystallographic data for this paper. These data can
be obtained free of charge via the Internet at www.ccdc.ca-
Su p p or tin g In for m a tion Ava ila ble: Tables of atomic
coordinates, bond lengths and bond angles, anisotropic dis-
placement parameters, and hydrogen coordinates for com-
pounds 4a , 4b, 7a , 8b, 9, 11, 12, and 15. This material is
available free of charge via the Internet at http://pubs.acs.org.
(43) Spek, A. L. PLATON, A Multipurpose Crystallographic Tool;
Urecht University: Urecht, The Netherlands, 2003.
OM030352P