Synthesis, spectroscopic, and substituent-dependent self-assembling structural characterization of ferrocenyl-containing silanediols, Fc(R)Si(OH)2, R = Me, CH2=CHCH2, n-Bu, t-Bu, Ph, c-Hx, including transformation to a ferrocenyl stannasiloxane, [OSiFc(n-Bu)O(t-Bu2)Sn]2

Article abstract of DOI:10.1021/om010378l

The hydrolysis of ferrocenyldichlorosilanes, Fc(R)SiCl₂, Fc = (η⁵-C₅H₅)Fe(η⁵-C₅ H₄), R = methyl (Me), 1a; 2-propenyl (allyl), 1b; n-butyl (n-Bu), 1c; tert-butyl (t-Bu), 1d; phenyl (Ph), 1e; cyclohexyl (c-Hex), 1f, leads to the formation of new ferrocenylsilanediols, Fc(R)Si(OH)₂, 2a-f. The diols have been characterized by ¹H, ¹³C, and ²⁹Si NMR, IR, UV/vis, and elemental analysis and in the case of 2d and 2f by single-crystal X-ray diffraction. The latter two compounds reveal a primary double-chain structure of silanediols achieved via intermolecular hydrogen bonding, with further hydrogen bonding resulting in ladder structures. The reactivity of Fc(n-Bu)Si(OH)₂ was probed by its reaction with di-tert-butyldichlorostannane to form the distannadisiloxane [OSiFc(n-Bu)OSn(t-Bu)₂]₂, whose single-crystal structure was shown to be that of the cis isomer, which in solution formed a mixture of the cis and trans isomers.

Full text of DOI:10.1021/om010378l

4734
Organometallics 2001, 20, 4734-4740
Syn th esis, Sp ectr oscop ic, a n d Su bstitu en t-Dep en d en t
Self-Assem blin g Str u ctu r a l Ch a r a cter iza tion of
F er r ocen yl-Con ta in in g Sila n ed iols, F c(R)Si(OH)2, R )
Me, CH2dCHCH2, n -Bu , t-Bu , P h , c-Hx, In clu d in g
Tr a n sfor m a tion to a F er r ocen yl Sta n n a siloxa n e,
[OSiF c(n -Bu )O(t-Bu 2)Sn ]2
Enrique A. Reyes-Garc´ıa, Francisco Cervantes-Lee, and Keith H. Pannell*
Department of Chemistry, University of Texas at El Paso, El Paso, Texas 79968-0513
Received May 8, 2001
The hydrolysis of ferrocenyldichlorosilanes, Fc(R)SiCl2, Fc ) (η5-C5H5)Fe(η5-C5H4), R )
methyl (Me), 1a ; 2-propenyl (allyl), 1b; n-butyl (n-Bu), 1c; tert-butyl (t-Bu), 1d ; phenyl (Ph),
1e; cyclohexyl (c-Hex), 1f, leads to the formation of new ferrocenylsilanediols, Fc(R)Si(OH)2,
2a -f. The diols have been characterized by 1H, 13C, and 29Si NMR, IR, UV/vis, and elemental
analysis and in the case of 2d and 2f by single-crystal X-ray diffraction. The latter two
compounds reveal a primary double-chain structure of silanediols achieved via intermolecular
hydrogen bonding, with further hydrogen bonding resulting in ladder structures. The
reactivity of Fc(n-Bu)Si(OH)2 was probed by its reaction with di-tert-butyldichlorostannane
to form the distannadisiloxane [OSiFc(n-Bu)OSn(t-Bu)2]2, whose single-crystal structure was
shown to be that of the cis isomer, which in solution formed a mixture of the cis and trans
isomers.
In tr od u ction
and dendrimers.5 In addition to a series of ferrocene-
containing siloxane and metallasiloxane silanols,6 fer-
rocene-containing disiloxanediols and silanediols have
been reported,6,7 of particular interest since silanediols
and silanetriols crystallize in the solid state into su-
The synthesis of organosilicon materials containing
transition metals,1 and more recently those containing
ferrocenyl and ferrocenylene units,2 has been the center
of extensive investigations. In the case of ferrocenyl
derivatives such activity is driven by the reversible
redox behavior, permeability, and thermal and photo-
chemical stability that this group can impart to molec-
ular systems, such as polymers,3 catalyst precursors,4
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Vicari, R.; Cervantes-Lee, F.; Pannell, K. H. Organometallics 1990, 9,
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10.1021/om010378l CCC: $20.00 © 2001 American Chemical Society
Publication on Web 10/03/2001

Ferrocenyl-Containing Silanediols
Organometallics, Vol. 20, No. 22, 2001 4735
pramolecular arrays.8 Although a range of metallasi-
loxanes M-O-Si, M ) Si, Ge, Sn, B, are known,9 few
systems that incorporate electrochemically active mol-
ecules such as ferrocene have been explored.
We report the synthesis of new ferrocenylsilanediol
materials containing a number of organic substituents,
Fc(R)Si(OH)2, Fc ) (η5-C5H5)Fe(η5-C5H4), R ) methyl
(Me), 2a ; 2-propenyl (allyl), 2b; n-butyl (n-Bu), 2c; tert-
butyl (t-Bu), 2d ; phenyl (Ph), 2e; cyclohexyl (c-Hex), 2f,
formed by the hydrolysis of the corresponding ferroce-
nylsilanedichlorides, Fc(R)Si(Cl)2, 1a -f. Along with
their spectroscopic characterization, we report the single
X-ray diffraction analysis of Fc(t-Bu)Si(OH)2 and Fc(c-
Hx)Si(OH)2, and that of the stannasiloxane [OSiFc(n-
Bu)OSn(t-Bu)2]2 derived from the reaction of 2c with
(t-Bu)2SnCl2.
F igu r e 1. (a) Structure and atom-numbering scheme of
Fc(t-Bu)Si(OH)2; thermal ellipsoids at 50% probability
level.
Resu lts a n d Discu ssion
Syn th esis a n d Sp ectr a of F c(R)SiX2, X ) Cl, OH.
All except one of the dichloro compounds were prepared
by the direct salt-elimination sequence outlined in eq
1, R ) Me, 1a ; allyl, 1b; t-Bu, 1d ; Ph, 1e; c-Hex, 1f.
tween 2 and 4 ppm for exchanging OH protons. The
characteristic sharp SiO-H stretching frequencies of
silanols, centered approximately at 3680-3640 cm-1
,
were observed together with the corresponding broad
H-bonded frequency at approximately 3400 cm-1. The
observed vibrations belonging to the ferrocenyl sub-
stituent are in agreement with those already reported
for similar compounds.12,14-16
FcHgCl + n-BuLi f [Fc]-Li+
(1a)
[Fc]-Li+ + RSiCl3 f FcSi(R)Cl2 + LiCl (1b)
Sin gle-Cr yst a l X-r a y Diffr a ct ion St u d ies of 2d
a n d 2f. The molecular structures of compounds 2d and
2f illustrated in Figures 1 and 2 both contain two
molecules per asymmetric unit. Table 1 provides a data
collection and refinement summary, and Tables 2 and
3 contain selected bond lengths and angles, and inter-
molecular bond distances and angles, respectively. The
X-ray crystal structures of both compounds show that
they belong to the triclinic space group P1h space group
and in both Z ) 4. Each of the structures forms
hydrogen-bonded centrosymmetric dimeric units, from
symmetry-related monomers. These units link further
into infinite chains through additional hydrogen bond-
ing, as shown in Figures 3 and 4; all hydrogen bonds
are intermolecular. The pattern of hydrogen bonding is
more clearly noted in Scheme 1 for the two compounds.
The ladder chains run close to the [001] direction for
2d and to the [100] direction for 2f, as illustrated by
the corresponding stereodiagrams; hydrogen-bonding
parameters for 2d and 2f are provided in Table 3. The
Ferrocenyldichloro(n-butyl)silane, 1c, was prepared
by the HCl treatment of the [1]-(chloro(n-butyl)silylene)-
ferrocenophane, eq 2.
[Fc]2-2Li+ + n-BuSiCl3 f [(η5-C5H4)2Fe]Si(n-Bu)Cl
(2a)
[(η5-C5H4)2Fe]Si(n-Bu)Cl + HCl f FcSi(n-Bu)Cl2
(2b)
The 1H, 13C, and 29Si NMR spectra of compounds 1a -f
are fully consistent with their proposed structures and
related literature data for ferrocenyl-substituted chlo-
rosilanes.10,11 Hydrolysis of 1a -f was performed accord-
ing to published procedures for the preparation of
organosilanols, eq 3.12-14
(10) (a) Sharma, H.; Cervantes-Lee, F.; Mahmoud, J . S.; Pannell,
K. H. Organometallics 1999, 18, 399. (b) J akle, F.; Rulkens, R.; Zech,
G.; Foucher, D. A.; Lough, A. J .; Manners, I. Chem. Eur. J . 1998, 4,
2117. (c) Herberhold, M.; Steffl, U.; Milius, W.; Wrackmeyer, B. Angew.
Chem., Int. Ed. Engl. 1996, 35, 1803. (d) Rulkens, R.; Lough, A. J .;
Manners, I. Angew. Chem., Int. Ed. Engl. 1996, 35, 1805. (e) Altmann,
R.; Gausset, O.; Horn, D.; J urkschat, K.; Schu¨rmann, M. Organome-
tallics 2000, 19, 430. (f) Sharma, H.; Vincenti, S. P.; Vicari, R.;
Cervantes-Lee, F.; Pannell, K. H. Organometallics 1990, 9, 2109.
(11) Foucher, D.; Ziembinski, R.; Petersen, R.; Pudelski, M. E.; Ni,
Y.; Massey, J .; J aeger, C. R.; Vancso, J . G.; Manners, I. Macromolecules
1994, 27, 3992.
(12) MacLachlan, M. J .; Ginzburg, M.; Zheng, J .; Kno¨ll, O.; Lough,
A. J .; Manners, I. New J . Chem. 1998, 22, 1409.
(13) Cella, J . A.; Carpenter, J . C. J . Organomet. Chem. 1994, 480,
23.
(14) MacLachlan, M. J .; Zheng, J .; Lough, A. J .; Manners, I.
Organometallics 1999, 18, 1337.
(15) 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.
In all cases the resulting diols were yellow solids
obtained in moderately high (78%) to low (12%) yields.
Ferrocenyl(methyl)silanediol was the most insoluble of
the compounds synthesized; consequently its NMR
spectrum was acquired in DMSO-d6 in which a single
sharp resonance at 5.98 ppm indicated the presence of
strongly solvent-hydrogen-bonded silanediol. The 1H
NMR spectra of the other silanediols were obtained in
CDCl3 and exhibited the typical broad resonance be-
(16) MacLachlan, M. J .; Lough, A. J .; Geiger, W. E.; Manners, I.
Organometallics 1998, 17, 1873.

4736 Organometallics, Vol. 20, No. 22, 2001
Reyes-Garc´ıa et al.
the other chain is comprised solely by the remaining
molecule. Both chains differ in orientation with respect
to the unit cell of the structure.
Overall the chains observed for 2f are similar to those
described for the related compound (cHx)2Si(OH)2, while
in 2d a deviation from the structure of t-Bu2Si(OH)2 is
apparent.18,20 To our knowledge the only other silanol
or silanediol structures characterized to date containing
a ferrocene moiety, with related self-assembling, are Fc3-
SiOH and diferrocenylsilanediol, Fc2Si(OH)2, and the
related disiloxanediol [HOFc2Si]2O.12,14,15
Syn th esis a n d Ch a r a cter iza tion of 3. There are
several reports in the literature concerning the capacity
of silanols and stannoxanes to form mixed stannasilox-
anes.9,21 Thus, we have preliminarily evaluated the new
silanediols with respect to their capacity to be incorpo-
rated into such molecular species.
The reaction between Fc(n-Bu)Si(OH)2 and t-Bu2-
SnCl2 in the presence of triethylamine was carried out
at room temperature by slow addition of the chlorostan-
nane to the silanediol/amine mixture in a THF solution,
eq 4.
F igu r e 2. Structure and atom-numbering scheme of Fc-
(cHx)Si(OH)2; thermal ellipsoids at 50% probability level.
Si-O bond lengths in 2d and 2f range from 1.636 to
1.657 Å, and the O-Si-O angles are in the range
106.1-108.1°, all similar to those reported in previous
studies.22
Self-assembly in organometallic systems has been
recently emphasized,17 and Scheme 1 illustrates a
simplified version of the self-assembled structure for 2d
that can be observed in the stereodiagram presented in
Figure 3. Overall the ladder type structure is achieved
by linking a pair of dimeric units A and B, which are
in turn held together by a pair of H-bonds. This
H-bonding scheme results in an octagonal ring between
O3, Si2, H4, and O4 with their centrosymmetric equiva-
lents. There are two distinct crystallographically inde-
pendent dimeric units within the structure in which
either all four of the OH groups are involved in H-
bonding (B) or only two of them (A). Thus in A H1 does
not participate in hydrogen bonding, resulting in the
units A and B being linked together with a single
H-bond. This is in contrast to the related compound
t-Bu2Si(OH)2, which attains maximum hydrogen bond-
ing.18 Figure 3 illustrates that the two ferrocenyl
molecules are parallel to in each dimeric unit but
orthogonal to those in the adjacent dimeric units above
and below in the chain.19
In contrast to 2d , silanediol 2f forms a more exten-
sively hydrogen-bonded structure (Figure 4), as has also
been observed for (c-Hx)2Si(OH)2.20 All the dimeric units
are of type B, forming two types of crystallographically
independent chains. Each chain type consists entirely
of symmetry-related monomers. The dimeric units are
linked along the ladder chain via two H-bonds. In 2f
the ferrocenyl groups of each dimeric unit are parallel
to one another and remain essentially unchanged on the
adjacent units. Only one of the two molecules in the
asymmetric unit forms one of the observed chains, while
The reaction was monitored by IR spectroscopy. After
15 h no starting material was present, and after
filtration, the solvent was removed under vacuum to
yield 3 as a yellow solid. The IR spectrum of 3 confirms
formation of a stannasiloxane by the presence of a new
band at 955 cm-1 that has been attributed to Si-O-
Sn vibration.20 The 13C, 29Si, and 119Sn NMR analysis
of the recrystallized material indicates the product to
be a mixture of the cis and trans isomers. The 119Sn
NMR of compound 3, -158.3 and -158.5 ppm, is in close
agreement with those of other eight-membered ring
stannasiloxanes with Sn-(O-Si-O)2-Sn frameworks
(-149.5 to -166.7 ppm).22 The 29Si NMR shows two
signals of almost equal intensity at -27.08 and -27.14
ppm, considerably downfield from the related chloride
(-55.7, -56.0 ppm) and fluoride (-38.9, -39.1 ppm)
substituted t-Bu2Sn(OSi-t-Bu(X)O)2Sn-t-Bu2 compounds,
but close to that of cyclo-(t-Bu2SiOSn-t-Bu2O)2 (-25.7
ppm). Furthermore, the 13C NMR of 3 exhibits a set of
doublets for each of the carbon resonances belonging to
the substituted Cp rings, confirming the presence of the
cis/trans mixture.
(17) Haiduc, I.; Edelmann, F. T. Supramolecular Organometallic
Chemistry; Wiley-VCH: New York, 1999.
(18) Buttrus, N. H.; Eaborn, C.; Hitchcock, P. B.; Saxena, A. K. J .
Organomet. Chem. 1985, 284, 291.
(19) Cervantes-Lee, F.; Sharma, H. K.; Pannell, K. H.; Derecskei-
Kovacs, A.; Marynick, D. S. Organometallics 1998, 17, 3701.
(20) Buttrus, N. H.; Eaborn, C.; Hitchcock, P. B.; Lickiss, P. D.;
Taylor, A. D. J . Organomet. Chem. 1986, 309, 25.
(21) Voigt, A.; Murugavel, R.; Ritter, U.; Roesky, H. W. J . Orga-
nomet. Chem. 1996, 521, 279.
Crystals suitable for X-ray analysis were obtained,
and the resulting structure is illustrated in Figure 5 and
crystallographic parameters and selected bond lengths
and angles are provided in Tables 1 and 2. Figure 5a
(22) Beckmann, J .; Mahieu, B.; Nigge, W.; Schollmeyer, D.; Schu¨r-
mann, M. J urkschat, K. Organometallics 1998, 17, 5697.

Ferrocenyl-Containing Silanediols
Organometallics, Vol. 20, No. 22, 2001 4737
Ta ble 1. Cr ysta llogr a p h ic Da ta for Com p ou n d s 2d , 2f, a n d 3
formula
color, habit
cryst syst
cryst size, mm
space group
a, Å
C14H20FeO2Si
orange prism
triclinic
C16H22FeO2Si
orange prism
triclinic
0.60 × 0.60 × 0.40
P1h
5.609(2)
16.443(6)
17.035(6)
87.39(3)
82.80(3)
88.29(3)
1556.7(10)
4
C44H72Fe2O4Si2Sn2
orange, irregular fragment
monoclinic
0.60 × 0.44 × 0.42
C2/c
25.053(8)
9.591(4)
22.917(8)
90
0.32 × 0.44 × 0.80
P1h
10.8470(10)
10.8770(10)
13.088(2)
101.440(10)
105.240(10)
91.710(10)
1454.8(3)
4
b, Å
c, Å
R, deg
â, deg
115.77(2)
90
4959(3)
γ, deg
V, Å3
Z
F
4
calcd, mg/m3
1.389
1.107
640
1.409
1.041
696
1.434
1.654
2192
µ, mm-1
F(000)
θ range, deg
3.5-45.0
0 e h e 11
-11 e k e 11
-14 e l e 13
4066
3826/0.0211
3428
326
3.5-45.0
0 e h e 6
-17 e k e 17
-18 e l e 18
4573
4072/0.0170
3386
362
2.31-22.54
-12 e h e 0
-2 e k e 10
-22 e l e 24
3460
3460/0.0550
3226
247
index ranges
no. of reflns collected
no. of ind reflns/Rint
no. of obsd reflns with (I>2.0σ(I))
no. of params
goodness of fit (F2)
1.01
1.55
1.146
R1(F) (I>2σ(I))
0.0420
0.0697
0.44/-0.40
0.0502
0.0682
0.76/-0.42
0.0404
0.1140
0.601/-0.674
wR2(F2) (all data)
largest diff peak/hole, e/A3
Ta ble 2. Selected Bon d Len gth s a n d An gles for
Com p ou n d s 2d , 2f, a n d 3a
coordination of both Si and Sn atoms. The Sn-O, Sn-
C, Si-O, and Si-C bond lengths and the Si-O-Sn bond
angles are all comparable to those of reported eight-
member stannasiloxanes.22 The crystal packing of 3
shows all of the ferrocenyl moieties arranged parallel
to one another in adjacent molecules, displaying no form
of interaction between them. The cis isomer isolated in
the solid state contrasts with the structure obtained for
the related stannasiloxane t-Bu2Sn[OSi(t-Bu)FcO]2Sn-
t-Bu2, which was isolated as the trans isomer, and this
observation illustrates the close energy of these two
geometries.
C14H20FeO2Si
C16H22FeO2Si
Bond Lengths (Å)
Si(1)-O(1)
1.648(3) Si(1)-O(1)
1.636(3) Si(1)-O(2)
1.650(3) Si(2)-O(3)
1.618(3) Si(2)-O(4)
1.838(3) Si(1)-C(1)
1.858(4) Si(1)-C(21)
1.859(3) Si(2)-C(11)
1.678(4) Si(2)-C(27)
1.657(4)
1.639(4)
1.645(4)
1.642(4)
1.848(5)
1.860(7)
1.834(5)
1.870(6)
Si(1)-O(2)
Si(2)-O(3)
Si(2)-O(4)
Si(1)-C(10)
Si(1)-C(11)
Si(2)-C(22)
Si(2)-C(25)
Bond Angles (deg)
O(1)-Si(1)-O(2)
O(3)-Si(2)-O(4)
108.0(1) O(1)-Si(1)-O(2)
106.1(2)
108.1(2)
108.4(2)
Spectroscopic analysis of the crystals from which the
X-ray structure was determined illustrated the immedi-
ate presence of both cis and trans isomers, thereby
demonstrating the facile ring-opening and re-formation
of the stannasiloxane in solution. This observation has
been previously made in related stannasiloxanes, t-Bu2-
Sn(OSi-t-BuXO)2Sn-t-Bu2 (X ) F, Cl),21 and cyclo-(Ph2-
SiOSnR2O)2 R ) (CH2)3NMe2.23
107.3(1) O(3)-Si(2)-O(4)
C(10)-Si(1)-C(12) 111.2(2) C(1)-Si(1)-C(21)
C(22)-Si(2)-C(25) 114.8(2) C(11)-Si(2)-C(27) 109.1(3)
44H72Fe2O4Si2Sn2
Bond Lengths (Å)
C
Sn-O(1)
1.955(4)
1.957(4)
2.155(6)
2.172(6)
1.607(4)
1.604(4)
1.864(6)
1.876(6)
Sn-O(2)
Sn-C(15)
Sn-C(19)
Si(1)-O(1)
Si(1)-O(2)
Si(1)-C(1)
Si(1)-C(11)
Exp er im en ta l Section
NMR spectra were collected with
a Bruker 300 MHz
Bond Angles (deg)
O(1)-Si(1)-O(2)
O(1)-Si(1)-C(1)
O(1)-Si(1)-C(11)
O(2)-Si(1)-C(1)
O(2)-Si(1)-C(11)
C(1)-Si(1)-C(11)
Si(1)-O(1)-Sn(1)
Si(1)-O(2)-Sn(1)
C(15)-Sn-C(19)
111.7(2)
110.3(2)
106.4(3)
106.9(3)
109.8(3)
111.9(3)
149.7(3)
143.9(3)
121.6(2)
multinuclear spectrometer; IR spectra were acquired with a
Perkin-Elmer 1600 FT-IR spectrophotometer in NaCl cells in
CH2Cl2 or CCl4 solvents; UV/vis spectra were recorded with a
Lambda 14 Perkin-Elmer spectrophotometer. Melting points
were determined in a Mel-Temp II instrument in tubes
previously purged with argon and then sealed with a propane
torch and are uncorrected. Elemental analyses were performed
by Galbraith Laboratories Inc. Chlorosilane compounds were
purchased from Gelest; all other chemicals were obtained from
Aldrich.
a
Symmetry transformation used to generate equivalent atoms:
-x + 1, y, -z + 1/2.
All synthetic manipulations were performed under an inert
atmosphere of prepurified dinitrogen or argon, employing
standard Schlenk techniques for the handling of air-sensitive
shows the molecular structure of 3, which is a dimer
with crystallographic C2 symmetry. Figure 5a also
illustrates the cis nature with respect to the two
ferrocenyl groups. Figure 5b shows the twist conforma-
tion adopted by the molecule as well as the tetrahedral
(23) Beckmann, J .; J urkschat, K.; Kaltenbrunner, U.; Pieper N.;
Schu¨rmann, M. Organometallics 1999, 18, 1586.

4738 Organometallics, Vol. 20, No. 22, 2001
Reyes-Garc´ıa et al.
Ta ble 3. In ter m olecu la r Bon d Dista n ces a n d An gles for Com p ou n d s 2d a n d 2fa
atoms
distances (Å)
angle (deg)
H4- - -O3A
symmetry
O4-H4- - -O3A
O4-H4
0.903
0.981
1.000
0.942
0.955
1.132
0.800
1.842
1.779
1.830
2.191
1.912
1.722
2.358
168.9
176.4
176.2
149.3
158.2
162.9
162.9
O3A:
(-x + 1, -y + 1, -z + 1)
O3-H3- - -O2
O2-H2- - -O1B
O1-H1- - -O2B
O2-H2- - -O1A
O3-H3- - -O4A
O4-H4- - -O3C
O3-H3
O2-H2
O1-H1
O2-H2
O3-H3
O4-H4
H3- - -O2
O2:
(x, y, z)
H2- - -O1
O1B:
(-x + 1, -y + 1, -z + 2)
H1- - -O2B
H2- - -O1A
H3- - -O4A
H4- - -O3C
O2B:
(x + 1, y, z)
O1A:
(-x +1, -y, -z)
O4A:
(-x, -y, -z)
O3C:
(x - 1, y, z)
a
H1 is not involved in hydrogen bonding (see stereodiagram).
F igu r e 3. Stereodiagram of Fc(t-Bu)Si(OH)2 showing the hydrogen-bonded chains.
F igu r e 4. Stereodiagram of Fc(c-Hx)Si(OH)2 showing the hydrogen-bonded chains along the x-axis.
reagents. Solvents and reagents were dried prior to use by
conventional methods: tetrahydrofuran (THF) was distilled
over deep purple sodium/benzophenone ketyl; hexanes over
sodium; diethyl ether over lithium aluminum hydride; and
triethylamine over sodium. Methyltrichlorosilane (MeSiCl3)
was distilled over anhydrous potassium carbonate and stored
over molecular sieves; allyltrichlorosilane (CH2dCHCH2SiCl3),
n-butyl trichlorosilane (n-BuSiCl3), and phenyltrichlorosilane
(PhSiCl3) were distilled and stored over 3 Å molecular sieves,
cyclohexyltrichlorosilane (c-HxSiCl3) was purified by vacuum
distillation, and tert-butyltrichlorosilane (t-BuSiCl3) and di-
tert-butyldichlorostannane (t-Bu2SnCl2) were used as received
from Gelest. All glassware joints and stopcocks were fitted with
Teflon sleeves to avoid silicone grease contamination.
The ferrocenyldichlorosilanes 1a , 1b, 1d , 1e, and 1f were
synthesized by the published route for 1a using ferrocenyl-
lithium and the appropriate RSiCl3;24 a typical example is
described below.
stirred solution of CH2dCHCH2SiCl3 in 30 mL of THF. The
solution was permitted to warm to ambient temperature and
stirred for 15 h. The solvent was removed in vacuo, and the
solid residue was extracted with hexanes and filtered through
Celite. After removal of n-Bu2Hg, distillation at 122-124 °C/
0.2 mm/Hg yielded Fc(CH2CHCH2)SiCl2 as a red liquid in 71%
yield (3.5 g, 10.8 mmol). NMR (CDCl3): 1H (δ, ppm) 2.31 (Si-
CH2), 4.30 (Fc), 4.39 (Fc), 4.53 (Fc), 5.19 (CHdCH2), 5.90 (CHd
CH2); 13C, 28.80 (Si-CH2), 68.19 (Fc), 72.07 (Fc), 73.27 (Fc),
117.40 (CHdCH2), 129.54 (CHdCH2); 29Si, 18.8.
Complexes 1d , 1e, and 1f were prepared in a similar
manner, and the various bp’s, yields, and NMR spectroscopic
data for the new materials are outlined below.
1d : 150-156 °C/0.2 mmHg, 52% (1.0 g, 2.9 mmol). NMR
(CDCl3): 1H (δ, ppm) 0.98 (CH3), 4.15 (Fc); 13C, 23.5 (C(CH3)3),
24.9 (C(CH3)3) 64.0 (Fc), 69.8 (Fc), 72.4 (Fc), 74.5 (Fc); 29Si,
30.4.
(24) Foucher, D.; Ziembinski, R.; Petersen, R.; Pudelski, M. E.; Ni,
Y.; Massey, J .; J aeger, C. R.; Vancso, J . G.; Manners, I. Macromolecules
1994, 27, 3992.
(25) Seyferth, D.; Hofmann, H. P.; Burton, R.; Helling, J . F. Inorg.
Chem. 1962, 1, 227.
Fer r ocen yl(2-pr open yl)dich lor osilan e,Fc(CH2dCHCH2)-
SiCl2 (1b). A solution of [Fc]-Li+ prepared from FcHgCl25 (6.3
g, 15.0 mmol) and 19.0 mL of n-BuLi in 70 mL of THF was
added at -78 °C to 2.2 mL (15.0 mmol) of a magnetically

Ferrocenyl-Containing Silanediols
Organometallics, Vol. 20, No. 22, 2001 4739
) 7.5 Hz); 13C, 65.20 (Fc), 69.4 (Fc), 72.3 (Fc), 73.7 (Fc), 128.1
(Ph), 131.3 (Ph), 133.3 (Ph), 133.7 (Ph); 29Si, 11.0.
Sch em e 1. Self-Assem blin g Netw or k for 2d (R )
t-Bu ) (left) a n d 2f (R ) c-Hx) (r igh t)a
1f: 197-200 °C/0.2 mmHg, 44% (0.34 g, 1.1 mmol). NMR
(CDCl3): 1H (δ, ppm) 1.24-1.88 (c-Hx), 4.27 (Fc), 4.32 (Fc),
4.47 (Fc); 13C, 26.3 (c-Hx), 26.5 (c-Hx), 27.3 (c-Hx), 31.9 (c-Hx),
69.7 (Fc), 72.3 (Fc), 74.2 (Fc); 29Si, 25.7.
Compound 1c was synthesized by the ring-opening of the
corresponding ferrocenophane using a general literature pro-
cedure:14 96-97 °C/0.15 mmHg. NMR (C6D6): 1H (δ, ppm) 0.78,
1.09-1.14, 1.20-1.23, 1.49-1.51 (n-Bu); 4.07 (Fc), 4.15 (Fc),
4.19 (Fc), 13C, 13.73, 22.0, 25.1, 25.7 (n-Bu), 66.4 (Fc), 69.6 (Fc),
72.4 (Fc), 73.6 (Fc); 29Si, 24.5.
Syn th esis of F er r ocen yl(R)sila n ed iols 2a -f. Hydrolysis
of Fc(R)SiCl2 compounds 1a -f was performed according to the
general synthetic route outlined below specifically for 2a ;
similar procedures were used in the preparation of compounds
2b-e.
F er r ocen yl(m eth yl)sila n ed iol, F c(Me)Si(OH)2 (2a ). A
diethyl ether solution of Fc(Me)SiCl2 (0.90 g, 3.01 mmol) was
slowly added over a period of 1 h to a cooled (0 °C) solution of
water (2.1 equiv, 0.12 mL) and Et3N (2.0 equiv, 0.84 mL) in
20 mL of ether and 5 mL of acetone (to provide homogeneity).
After addition was complete the mixture was further stirred
for 40 min while warming to room temperature and concen-
trated to approximately one-tenth of the original volume.
Hexane (∼30 mL) was added to promote precipitation, and the
resulting mixture was filtered in vacuo to remove the hydro-
chloride salt. The yellow solution obtained was concentrated
in vacuo until one-tenth the volume remained. The mixture
was gravity filtered, and the solid product was washed with
cold hexanes. The filtrate was concentrated to give a yellow
solid that was redissolved in warm hexanes and immediately
cooled to 0 °C to precipitate the product. The solid fractions
were combined and purified by column chromatography (80-
200 mesh silica gel, 20 × 1 cm) with Et2O, and the solvent
was removed under reduced pressure, providing a pale yellow
solid. This material was insoluble in hexane and CCl4,
moderately soluble in hot CH2Cl2, CHCl3, and C6D6 or CDCl3,
and completely soluble in Et2O, THF, and DMSO; mp 146-
147 °C, 79% yield (0.62 g, 2.4 mmol). NMR: 1H (DMSO-d7)
0.18 (3H, s, CH3), 4.13 (7H, s, η5-C5H5 and η5-C5H4), 4.27 (2H,
η5-C5H4), 13C 0.16 (CH3), 68.22 (η5-C5H5), 70.19 (η5-C5H4), 70.45
(ipso-C), 72.76 (η5-C5H4), 29Si -16.5. IR (ν, cm-1), CH2Cl2, 3652
(m, sh), 3393 (w, br), 3093 (w), 1423 (w), 1171 (m), 1106 (m),
1037 (m), 1002 (w). UV/vis (λmax, nm): CH2Cl2, 97 (451). Anal.
Found (Calcd): C, 49.23 (50.39); H, 5.21 (5.38).
a
The Si atom numbering for 2d reflects that illustrated in
Figure 3 to permit recognition of the two crystallographically
independent dimeric units.
2b: mp 94-96 °C, 71% yield (0.66 g, 2.3 mmol). NMR: 1H
1.87-1.90 (2H, d, Si-CH2), 3.84 (2H, br, OH), 4.19 (5H, s, η5-
C5H5), 4.25 (2H, t, η5-C5H4), 4.37 (2H, t, η5-C5H4), 4.97-5.08
(2H, m, CHdCH2), 5.93-5.96 (1H, m, CHdCH2), 13C 23.55 (Si-
CH2), 65.57 (ipso-C), 68.52 (η5-C5H5), 71.31 (η5-C5H4), 73.15 (η5-
C5H4), 114.87 (CHdCH2), 133.20 (CHdCH2), 29Si -14.9. IR (ν,
cm-1): CCl4, 3683 (st), 3399 (m, br), 3097 (m), 2975 (w), 1631
(w), 1418 (w), 1172 (st), 1107 (m), 1037 (m), 1002 (w), 901 (m).
UV/vis (λmax, nm): CH2Cl2, 114 (450). Anal. Found (Calcd): C,
54.52 (54.18); H, 5.47 (5.60).
2c: mp 112-114 °C, 71% yield (1.14 g, 3.7 mmol). NMR:
1H (CDCl3) 0.81-0.92 (5H, m, n-Bu), 1.34-1.50 (4H, m, n-Bu),
3.18 (2H, br, C), OH), 4.17 (5H, s, η5-C5H5), 4.22 (2H, d, η5-
C5H4), 4.36 (2H, d, η5-C5H4), 13C 13.34 (CH3), 14.87 (CH2), 24.59
(CH2), 25.85 (CH2), 66.10 (ipso-), 67.98(η5-C5H5), 70.83 (η5-
C5H4), 72.63 (η5-C5H4), 29Si -9.54. IR (ν, cm-1): CCl4, 3681 (w,
sh), 3346 (w, br), 3094 (w), 2957 (m), 2926 (m), 2871 (w), 1169
(m), 1107 (m), 1036 (m). UV/vis (λmax, nm): CH2Cl2, 93 (445).
Anal. Found (Calcd): C, 55.77 (55.27); H, 6.55 (6.62).
2d : mp 147-148 °C, 55% yield (0.58 g, 1.9 mmol). NMR:
1H (CDCl3) 0.96 (9H, s, CH3), 2.63 (2H, br, OH), 4.20 (5H, s,
η5-C5H5), 4.22 (2H, t,η5-C5H4), 4.38 (2H, t,η5-C5H4), 13C 18.10
(C(CH3)3), 25.74 (C(CH3)3), 64.47 (ipso-C), 68.30 (η5-C5H5),
71.34 (η5-C5H4), 73.69 (η5-C5H4), 29Si -9.80. IR (ν, cm-1): CCl4,
3683 (m, sh), 3644 (w), 3395 (w, br), 3097 (w), 2954 (st), 2932
F igu r e 5. (a) Structure and atom-numbering scheme of 3;
thermal ellipsoids at 50% probability level. (b) Plane view
showing the twist conformation.
1e: 143-146 °C/0.2 mmHg, 58% (1.2 g, 3.3 mmol). NMR
(CDCl3): 1H (δ, ppm) 4.30 (5H, Cp), 4.48 (2H, Cp), 4.59 (2H,
Cp), 7.50 (Ph), 7.51 (3H, m, Ph J ) 7.3 Hz), 7.88 (2H, d, Ph J

4740 Organometallics, Vol. 20, No. 22, 2001
Reyes-Garc´ıa et al.
(st), 2892 (m), 2857 (m), 1473 (m), 1463 (w), 1422 (w), 1391
(w), 1362 (w), 1169 (st), 1107 (m), 1036 (m), 1004 (m). UV/vis
(λmax, nm): CH2Cl2, 117 (450). Anal. Found (Calcd): C, 54.83
(55.27); H, 6.34 (6.63).
2e: mp 140-142 °C, 73% yield (0.33 g, 1.0 mmol). NMR:
1H (CDCl3) 3.21 (2H, br, OH), 4.10 (5H, s, η5-C5H5), 4.24 (2H,
d, η5-C5H4), 4.37 (2H, d, η5-C5H4), 7.38-7.43 (3H, m, Ph), 7.72-
7.75 (2H, m, Ph), 13C 65.30 (ipso-C), 68.58 (η5-C5H5), 71.59 (η5-
C5H4), 73.54 (η5-C5H4), 127.90 (Ph), 130.27 (Ph), 133.91 (Ph),
135.39 (Ph), 29Si -8.15. IR (ν, cm-1): CCl4, 3652 (m, sh), 3427
(w, br), 3070 (w), 3040 (w), 1429 (m), 1171 (st), 1036 (m), 904
(w). UV/vis (λmax, nm): CH2Cl2, 116 (451). Anal. Found (Calcd)
C, 58.76 (59.27); H, 5.02 (4.97).
2f: mp 144-147 °C, 72% yield (0.54 g, 1.6 mmol). NMR:
1H (CDCl3) 1.23-1.80 (10H, m, c-Hx), 2.61 (2H, br, OH), 4.19
(5H, s, η5-C5H5), 4.21 (2H, s, η5-C5H4), 4.37 (2H, s, η5-C5H4),
13C 26.06 (CH2), 26.64 (CH2), 26.69 (CH2), 27.60 (CH2), 65.64
(ipso-C), 68.33 (η5-C5H5), 71.29 (η5-C5H4), 73.38 (η5-C5H4),29Si
-11.7. IR (ν, cm-1): CCl4, 3683 (m, sh), 3376 (w, br), 3098 (w),
2923 (st), 2849 (s), 1447(m), 1261 (w), 1170 (m), 1106 (s), 1036
(st). UV/vis (λmax, nm): CH2Cl2, 110 (455). Anal. Found
(Calcd): C, 58.01 (58.19); H, 6.71 (6.71).
Syn th esis of 1,1,5,5-Tetr a -ter t-bu tyl-3,7-n -bu tyl-3,7-fer -
r ocen yl-2,4,6,8-t et r a oxa -3,7-d isila -1,5-d ist a n n a cyclooc-
ta n e, t-Bu 2Sn (OSi(n -Bu )F cO)2Sn -t-Bu 2 (3). To a 10 mL
THF solution of Fc(n-Bu)Si(OH)2 (0.089 g, 0.29 mmol) and
Et3N (4 equiv, 0.16 mL) maintained at room temperature
under an argon atmosphere was added slowly via syringe 10
mL of a THF solution of di-tert-butyltindichloride (0.089 g, 0.29
mmol). The solution became turbid after addition of the tin
halide and was stirred overnight. The mixture was concen-
trated under vacuum and filtered through Celite, and the
solids were dissolved in hexanes followed by filtration to
remove the hydrochloride salt. Evaporation of the yellow
solution yielded a crystalline powder. X-ray quality crystals
were obtained from the slow evaporation of a hexane solution
at room temperature; mp 204-206 °C, 61% yield (0.54 g, 0.5
mmol). NMR: 1H (CDCl3) 0.93, 1.11, 1.24, 1.35, 1.54 (unre-
solved), 4.08 (2H, s, η5-C5H5), 4.10 (2H, s, η5-C5H5), 4.14 (1H,
d, η5-C5H5), 4.17 (2H, m, η5-C5H4), 4.20 (2H, m, η5-C5H5), 13C
13.98 (CH3), 19.39 (CH2, d, J ) 15 Hz), 26.92 (CH2, t, J ) 4
Hz), 29.66 (SnCMe3, t, J ) 11 Hz), 37.76 (Sn-C, t, J ) 19 Hz),
46.05(CH2), 68.28 (η5-C5H5), 69.80 and 69.84 (η5-C5H4), 73.65
and73.70 (η5-C5H4), 74.53 (ipso-C), -27.08, 29Si -27.14, 119Sn
-158.3, -158.5. IR (ν, cm-1): CCl4, 3098 (w), 2956 (st), 2924
(st), 2871 (m), 2852 (st), 1467 (m), 1413 (w), 1368 (m), 1297
(w), 1261 (w), 1194 (w), 1165 (st), 1107 (m), 1079 (m), 1035
(st), 1004 (st), 955 (m), 893 (w), 818 (w), 688 (w). UV/vis (λmax
,
nm): Hex, 178 (440). Anal. Found (Calcd): C, 49.50 (49.30);
H, 6.84 (6.78).
Cr ysta l Str u ctu r e Deter m in a tion . Three orange crystals
of approximate dimensions 0.32 × 0.44 × 0.80 mm (2d ), 0.60
× 0.60 × 0.40 mm (2f), and 0.42 × 0.44 × 0.60 mm (3) were
mounted on glass fibers in a random orientation. Intensity
data were collected at room temperature for all compounds
using a Siemens/Bruker four-circle diffractometer with graphite-
monochromated Mo KR radiation; λ ) 0.71073 Å. Unit cell
parameters and standard deviations were obtained by least-
squares fit of 25 reflections randomly distributed in reciprocal
space in the 2θ range of 15-30°. The ω-scan technique was
used for intensity measurements in all cases. A range of 1.4°
in ω and variable speed of 3.00-15.00 deg/min was used for
2d and a 1.2° in ω-range, a 4.00-20.00 deg/min speed for 2f,
whereas for 3 the range was 1.5° in ω and the scanning
variable speed 4.00-20.00 deg/min. Background counts were
taken with a stationary crystal and a total background time
to scan time ratio of 0.5. Three standard reflections were
monitored in all cases every 97 reflections and showed no
significant decay for each crystal. The data were corrected for
Lorentz and polarization effects, and a semiempirical absorp-
tion correction was also applied to both data sets, giving a min./
max. transmission ratio of 0.387/0.431 for 2d and 0.513/0.618
for 2f. No absorption correction was applied in the case of 3.
All structures were solved by direct methods and refined using
the PC-version of the SHELEXTL PLUS crystallographic
software by Siemens. Full-matrix least-squares refinement
minimizing ∑w(Fo - Fc)2 was carried out with anisotropic
thermal parameters for non-hydrogen atoms. Hydrogen atoms
not attached to oxygen were placed at calculated positions
(C-H ) 0.96 Å; UH ) 0.08) during refinements, and those for
the hydroxy groups were located on a difference map. The
weighing scheme has the form w-1 ) σ2(F) + gF2, and the final
2
R factors the form R ) ∑|Fo - Fc|/∑Fo and Rw ) [w|Fo - Fc| /
2
1/2
∑wFo
] .
Ack n ow led gm en t. This research was supported by
the Welch Foundation, Grant AH-0546.
OM010378L