New investigations in silanediyl complex chemistry: Synthesis, structure, and bonding of 1-metalla-2-sila-1,3-dienes

Article abstract of DOI:10.1021/om980032j

The synthesis and chemical behavior of the intra- and intermolecular donor-stabilized silanediyl complexes (C₆H₄CH₂NMe₂-2)(Cl)Si=ML_n (4, ML_n = Cr(CO)₅ 5, ML_n = Fe(CO)₄), (C₆H₅HC=CH)(Cl)Si=ML_n·OP(NMe ₂)₃ (21, ML_n = Cr(CO)₅; 22, ML_n = Fe(CO)₄), and (C₆H₅-HC=CH)(C₆H₅)Si=Fe(CO) ₄·OP(NMe₂)₃ (23) is discussed. Nucleophilic substitution of the chloro atom in compounds 4 and 5 by different nucleophiles leads to a great variety of further functionalized silanediyl complexes of the type (C₆H₄CH₂NMe₂-2)(R)Si=ML_n (ML_n = Cr-(CO)₅: 7, R = CH₃; 9, R = C₆H₅; 11, R = P(C₆H₅)₂; 13, R = CH=CH₂. ML_n = Fe(CO)₄: 14, R = CH=CH₂; 15, R = CH₃). Moreover, the 1-metalla-2-sila-1,3-dienes (C₆H₄CH₂NMe₂-2)-(H ₂C=CH)Si=ML_n (13, ML_n = Cr(CO)₅; 14, ML_n = Fe(CO)₄) can be prepared by treatment of the hypervalent dichlorosilane (C₆H₄CH₂NMe₂-2)(H ₂C=CH)SiCl₂ (19) with the carbonylate dianions ML_n^2- (2, ML_n = Cr(CO)₅; 3, ML_n = Fe(CO)₄). Additionally, compounds of the latter type are accessible by photochemical coupling reactions of the pentavalent silane (C₆H₄-CH₂NMe₂-2)(CH ₃)SiH₂ (16) with the transition-metal carbonyls Cr(CO)₆ (17a), Fe(CO)₅ (17b), and (η5-C₅H₅)Mn(CO)₃ (17c), respectively. The intermolecular donor-stabilized 1-metalla-2-sila-1,3-dienes 21-23 can be prepared by the reaction of tetravalent dichlorosilanes [(R)-(H)C=CH](R′)SiCl₂ (20a, R = H, R′ = Cl; 20b, R = R′ = C₆H₅) with the carbonylmetalates 2 and 3 and in the presence of OP(NMe₂)₃.

Full text of DOI:10.1021/om980032j

Organometallics 1998, 17, 3299-3307
3299
New In vestiga tion s in Sila n ed iyl Com p lex Ch em istr y:
Syn th esis, Str u ctu r e, a n d Bon d in g of
1-Meta lla -2-sila -1,3-d ien es
Markus Weinmann,† Gerd Rheinwald, Laszlo Zsolnai,‡ Olaf Walter,‡
Michael Bu¨chner,‡ Berthold Schiemenz,‡ Gottfried Huttner,‡ and
Heinrich Lang*,§
Technische Universita¨t Chemnitz, Institut fu¨r Chemie, Lehrstuhl Anorganische Chemie,
Strasse der Nationen 62, D-09107 Chemnitz, Germany
Received J anuary 21, 1998
The synthesis and chemical behavior of the intra- and intermolecular donor-stabilized
silanediyl complexes (C6H4CH2NMe2-2)(Cl)SidMLn (4, MLn ) Cr(CO)5 5, MLn ) Fe(CO)4),
(C6H5HCdCH)(Cl)Si)MLn‚OP(NMe2)3 (21, MLn ) Cr(CO)5; 22, MLn ) Fe(CO)4), and (C6H5-
HCdCH)(C6H5)SidFe(CO)4‚OP(NMe2)3 (23) is discussed. Nucleophilic substitution of the
chloro atom in compounds 4 and 5 by different nucleophiles leads to a great variety of further
functionalized silanediyl complexes of the type (C6H4CH2NMe2-2)(R)SidMLn (MLn ) Cr-
(CO)5: 7, R ) CH3; 9, R ) C6H5; 11, R ) P(C6H5)2; 13, R ) CHdCH2. MLn ) Fe(CO)4: 14,
R ) CHdCH2; 15, R ) CH3). Moreover, the 1-metalla-2-sila-1,3-dienes (C6H4CH2NMe2-2)-
(H2CdCH)Si)MLn (13, MLn ) Cr(CO)5; 14, MLn ) Fe(CO)4) can be prepared by treatment
of the hypervalent dichlorosilane (C6H4CH2NMe2-2)(H2CdCH)SiCl2 (19) with the carbonylate
dianions MLn2- (2, MLn ) Cr(CO)5; 3, MLn ) Fe(CO)4). Additionally, compounds of the latter
type are accessible by photochemical coupling reactions of the pentavalent silane (C6H4-
CH2NMe2-2)(CH3)SiH2 (16) with the transition-metal carbonyls Cr(CO)6 (17a ), Fe(CO)5 (17b),
and (η5-C5H5)Mn(CO)3 (17c), respectively. The intermolecular donor-stabilized 1-metalla-
2-sila-1,3-dienes 21-23 can be prepared by the reaction of tetravalent dichlorosilanes [(R)-
(H)CdCH](R′)SiCl2 (20a , R ) H, R′ ) Cl; 20b, R ) R′ ) C6H5) with the carbonylmetalates
2 and 3 and in the presence of OP(NMe2)3.
In tr od u ction
Recently, we reported about the synthesis and reac-
tion chemistry of the acyclic heterobutadienes (C6H4-
CH2NMe2-2)(H2CdCH)SidS (type A molecule)1 and
(C6H2OtBu3-2,4,6)(RHCdCH)PdMo(η5-C5H5)(CO)2 (type
B molecule) (R ) H, singly bonded organic ligand).2,3
The latter compounds show a versatile reaction chem-
istry, both at the organometallic as well as at the
organic π-system.3,4
Molecules of structural type B can formally be sepa-
rated into an electron sextet species, the phosphenium
ion fragment (R)(R′)P+ (R, R′ ) singly bonded organic
-
ligand), and the anionic transition-metal fragment MLn
with a total of 16 valence electrons. In terms of the
concept of the isolobal rules,5 these building blocks are
equivalents of e.g. carbenes, silenes, and d6 ML5 or d8
ML4 transition-metal fragments (L ) two-electron donor
ligands). Replacement of the ionic (R)(R′)P+ and MLn
-
entities in type B molecules by neutral (R)(R′)Si and
MLn moieties produces the corresponding acyclic 1-met-
alla-2-sila-1,3-dienes of structural type C.6
* E-mail: heinrich.lang@chemie.tu-chemnitz.de.
† Max-Planck-Institut fu¨r Metallforschung, Pulvermetallurgisches
Laboratorium, Heisenbergstraâe 5, D-70563 Stuttgart, Germany.
E-mail: weinmann@aldix.mpi-stuttgart.mpg.de.
‡ Universita¨t Heidelberg, Anorganisch-Chemisches Institut, Im
Neuenheimer Feld 270, D-69120 Heidelberg, Germany.
§ Dedicated to Prof. Dr. Manfred Weidenbruch on the occasion of
his 60th birthday.
(1) Weinmann, M.; Gehrig, A.; Schiemenz, B.; Huttner, G.; Nuber,
B.; Rheinwald, G.; Lang, H. J . Organomet. Chem., in press. (b)
Weinmann, M.; Lang, H.; Walter, O.; Bu¨chner, M. In Organosilicon
Chemistry; Auner, N., Weis, J ., Eds.; VCH: Weinheim, Germany, 1994;
Vol. II (From Molecules to Materials).
In this study, we focus on different possibilities for
the preparation of inter- and intramolecular donor-
(2) (a) Karsch, H. H.; Reisacher, H. U.; Huber, B.; Mu¨ller, G.; J o¨rg,
K.; Malisch, W. New J . Chem. 1989, 13, 319. (b) Karsch, H. H.;
Reisacher, H. U.; Huber, B.; Mu¨ller, G.; J o¨rg, K.; Malisch, W. Angew.
Chem., Int. Ed. Engl. 1986, 25, 455.
(3) (a) Lang, H.; Leise, M.; Zsolnai, L. J . Organomet. Chem. 1990,
389, 325. (b) Lang, H.; Leise, M.; Zsolnai, L.; Fritz, M. J . Organomet.
Chem. 1990, 395, C30. (c) Lang, H.; Leise, M., J . Organomet. Chem.
1990, 393, C17.
(4) (a) Lang, H.; Leise, M.; Zsolnai, L., Polyhedron, 1992, 11, 1281.
(b) Lang, H. Phosphorus, Sulfur Silicon Relat. Elem. 1993, 77 and
literature cited therein. (c) Lang, H.; Leise, M.; Zsolnai, L. J . Orga-
nomet. Chem. 1993, 447, C1.
(5) Hoffmann, R. Angew. Chem., Int. Ed. Engl. 1982, 21, 711.
(6) Lang, H.; Weinmann, M.; Frosch, W.; Bu¨chner, M.; Schiemenz,
B. J . Chem. Soc., Chem. Commun. 1996, 1299.
S0276-7333(98)00032-6 CCC: $15.00 © 1998 American Chemical Society
Publication on Web 06/26/1998

3300 Organometallics, Vol. 17, No. 15, 1998
Weinmann et al.
Sch em e 1. Rea ction Beh a vior of th e Sila n ed iyl Com p lex 4 w ith Differ en t Su bstr a tes
stabilized heterobutadienes of structural type C: (i)
reaction of tetra- and pentacoordinated alkenyl-substi-
tuted chlorosilanes with carbonylate dianions and (ii)
treatment of chloro-functionalized silanediyl complexes
with alkenylmagnesium bromides. Likewise, the reac-
tion of (C6H4CH2NMe2-2)(Cl)SidMLn with various or-
ganic nucleophiles is described.
°C the intramolecular donor-stabilized silanediyl com-
plexes (C6H4CH2NMe2-2)(R)SidCr(CO)5 (7, R ) CH3;9
9, R ) C6H5;9,10 11, R ) P(C6H5)2; 13, R ) CHdCH2).
When the same reaction conditions are applied for the
preparation of the intramolecular donor-stabilized si-
lanediyl compounds (C6H4CH2NMe2-2)(R)SidFe(CO)4
(14, R ) CHdCH2; 15, R ) CH3), a multitude of
different reaction products are formed. However, pure
Resu lts a n d Discu ssion of Rea ction Ch em istr y
1. Syn th esis of In tr a m olecu la r Don or -Sta bilized
Sila n ed iyl Com p lexes. The synthesis of the chloro-
functionalized silanediyl compounds (C6H4CH2NMe2-2)-
(Cl) SidMLn (4, MLn ) Cr(CO)5;8 5, MLn ) Fe(CO)4)
proceeds by treatment of (C6H4CH2NMe2-2)SiCl3 (1)7
with the carbonylmetallates K2[Cr(CO)5] (2) and Na2-
[Fe(CO)4] (3), respectively. The yield of 4 is 53%, and
that of 5 is 49%.
While 4 can best be synthesized in tetrahydrofuran
solutions at -30 °C, it is of major importance that the
preparation of 5 has to be carried out in diethyl ether.
Changing the solvent in the synthesis of 5 has a
significant influence on the appropriate workup: in
tetrahydrofuran only dark-colored oils can be separated,
which always contain traces of paramagnetic materials.
This can be avoided when diethyl ether is used as
solvent; after crystallization from diethyl ether/n-pen-
tane, compound 5 can be obtained as a pale red solid.
Compounds 4 and 5 provide the constituents for the
preparation of further functionalized silanediyl com-
plexes, as depicted in Scheme 1. The reaction of 48 with
LiR (6, R ) CH3; 8, C6H5; 10, R ) P(C6H5)2) or
BrMgCHdCH2 (12) produces in tetrahydrofuran at -70
14 and 15 could not be isolated, by either chromatog-
raphy or crystallization methods. When the solvent is
changed from tetrahydrofuran to diethyl ether, com-
pounds 14 and 15 are easily accessible.
Moreover, an efficient possibility for the synthesis of
intramolecular donor-stabilized silanediyl complexes is
given by the photochemically induced dehydrogenative
coupling of 16-valence-electron transition-metal frag-
ments, generated from MLn(CO) (17a , MLn ) Cr(CO)5;
17b, MLn ) Fe(CO)4; 17c, MLn ) Mn(η5-C5H5)(CO)2),
with e.g. hypervalent (C6H4CH2NMe2-2)(CH3)SiH2 (16).
This type of reaction was first described by Corriu and
co-workers for (C10H6CH2NMe2-1,8)(C6H5)SidMLn (MLn
(9) Corriu, R. J . P.; Chauhan, B. P. S.; Lanneau, G. F. Organome-
tallics 1995, 14, 4014.
(10) (a) Chauhan, B. P. S.; Corriu, R. J . P.; Lanneau, G. F.; Priou,
C. Organometallics 1995, 14, 1657. (b) Handwerker, H.; Leis, C.;
Probst, R.; Bissinger, P.; Grohmann, A.; Kiprof, P.; Herdtweck, E.;
Blu¨mel, J .; Auner, N.; Zybill, C. Organometallics 1993, 12, 2162.
(7) (a) Auner, N.; Probst, R.; Hahn, F.; Herdtweck, E. J . Organomet.
Chem. 1993, 459, 25. (b) Probst, R.; Leis, C.; Gamper, S.; Herdtweck,
E.; Zybill, C.; Auner, N. Angew. Chem., Int. Ed. Engl. 1991, 30, 1132.
(8) Corriu, R. J . P.; Chauhan, B. P. S.; Lanneau, G. F. Organome-
tallics 1995, 14, 1646.

Silanediyl Complex Chemistry
Organometallics, Vol. 17, No. 15, 1998 3301
Ta ble 1. Selected NMR Da ta for Com p ou n d s 4, 7,
9, 11, 13-15, a n d 18
compd
CH2 (δ)
2J HH (Hz) NCH3 (δ) NCH3 (δ) 29Si (δ)
48
5
3.81, 4.68
4.45a
2.61, 3.29
13.4
15.0
14.2
13.9
13.9
14.7
14.4
14.5
8.6
2.66, 2.98 45.8, 46.6
2.50, 2.70 46.9, 48.2
1.74, 1.97 43.6, 46.4
2.66, 2.83 47.0, 48.8
2.89, 3.25 45.2b
2.84, 2.96 45.9, 47.9
1.99, 2.02 45.1, 46.8
1.97, 2.10 44.6, 47.1
2.71, 2.90 39.8, 48.6
120.4
ndd
124.6
116.9
nd
114.9
116.8
127.2
nd
79
99,10 3.77, 3.95
11
13
3.81, 4.90
3.90, 4.46
2.75, 3.36
2.87, 3.31
3.99c
) Fe(CO)4, (η5-C5H5)Mn(CO)2].11 The decisive disad-
vantage of this reaction is that it cannot be applied to
the synthesis of the heterobutadienes 13 and 14, since
in each case polymerization of the alkenylsilanes occurs.
A further synthetic route for the preparation of acyclic
1-metalla-2-sila-1,3-dienes is given by the reaction of
(C6H4CH2NMe2-2)(H2CdCH)SiCl2 (19) with an equimo-
lar amount of K2[Cr(CO)5] (2) or Na2[Fe(CO)4] (3).
Appropriate workup produces the heterobutadiene 13
or 14 in 43% or 35% yield.
14
1510a
18
a
One of the CH2 resonance signals is masked by the resonance
signal of the solvent. Broad resonance signal. c One of the CH2
resonance signals is masked by the resonance signal of the
cyclopentadienyl protons. nd ) not determined.
b
d
tetrahydrofuran/n-pentane (4, 7, 9, 11, 13, 21-23) or
diethyl ether/n-pentane (5, 14, 15, 18) solutions at -30
°C. When chromatographic methods are applied, an
irreversible fixation of the appropriate silanediyl com-
plexes on the surface of most common chromatographic
materials is observed. All compounds synthesized are
soluble in most common polar organic solvents and are
extremely sensitive to oxygen and moisture in the solid
state as well as in solution.
3. Str u ctu r e a n d Bon d in g. The most suitable
analytical method for the characterization of the syn-
thesized silanediyl compounds is 29Si NMR spectroscopy.
In comparison with those of their starting materials,
the resonance signals of the silanediyl complexes 4, 7,
9, 13-15, 18, and 21-23 are significantly shifted to
lower field.8-13 The 29Si resonance signals of the in-
tramolecular donor-stabilized silanediyls 4, 7, 9, 13-
15, and 18 are shifted thereby to a lower field (115-
127 ppm) than the intermolecular [(CH3)2N]3PO-
stabilized molecules 21-23 (75-84 ppm), due to their
electron donating capability being lower than that of
HMPT. On the other hand, the shifting of the 29Si
resonance signal chemical shift seems to be almost
independent of the transition-metal moiety (Fe(CO)4 or
Cr(CO)5) present (Table 1).
2. Syn th esis of In ter m olecu la r Don or -Sta bilized
Sila n ed iyl Com p lexes. Acyclic intermolecular donor-
stabilized heterobutadienes can be synthesized accord-
ing to a method first described by Zybill and co-
workers12 on treatment of (RHCdCH)(R′)SiCl2 (20a , R
) H, R′ ) Cl; 20b, R ) R′ ) C6H5) with the carbonyl-
metalates 2 and 3 in the presence of [(CH3)2N]3PO
(HMPT; )Do) in tetrahydrofuran at -30 °C. After
appropriate workup, the 1-metalla-2-sila-1,3-dienes 21-
23 are obtained in 35-60% yield as yellow (21) or red
(22, 23) solids.
1
The most striking feature of the H NMR spectra of
4, 7, 9, 11, and 13-15 is the appearance of two
resonance signals for the methyl groups of the NMe2
entity in the region of 2.0-3.3 ppm and an AB resonance
pattern between 2.7 and 4.9 ppm with coupling con-
2
stants of J HH ) 13-16 Hz for the methylene protons
of the built-in arm Me2NCH2 (Table 1), indicating that
both the methylene protons and the Me groups of the
NMe2 entity as well are diastereotopic. As a typical
example, the 1H NMR spectrum of 13 is depicted in
Figure 1.
Neither for the NMe2 nor for the NCH2 protons is
coalescence observed up to 115 °C. This confirms that
the lone pair of electrons at the nitrogen atom of the
C6H4CH2NMe2-2 ligand is strongly bonded to the silicon
atom. The appearance of two resonance signals in the
range of 44-48 ppm in the 13C{1H} NMR spectra also
confirms magnetically inequivalent amino methyl groups
(Table 1). In contrast, for the complex (C6H4CH2NMe2-
2)(C6H5)SidCr(CO)5 a coalescence temperature of 95 °C
was measured, while (C6H4CH2NMe2-2)2SidCr(CO)5 is
The purification of all synthesized intramolecular as
well as intermolecular donor-stabilized silanediyl com-
plexes has to be performed by crystallization from
(11) Corriu, R.; Lanneau, G.; Priou, C. Angew. Chem. 1991, 103,
1153; Angew. Chem., Int. Ed. Engl. 1991, 30, 1130.
(12) (a) Zybill, C.; Mu¨ller, G. Angew. Chem. 1987, 99, 683; Angew.
Chem., Int. Ed. Engl. 1987, 26, 669. (b) Zybill, C.; Wilkinson, D. L.;
Mu¨ller, G. Angew. Chem. 1988, 100, 574; Angew. Chem., Int. Ed. Engl.
1988, 27, 583. (c) Leis, C.; Zybill, C.; Lachmann, J .; Mu¨ller, G.
Polyhedron 1991, 11, 1163. (d) Leis, C.; Wilkinson. D. L.; Handwerker,
H.; Zybill, C. Organometallics 1992, 11, 514. (e) Zybill, C.; Wilkinson,
D. L.; Leis, C.; Mu¨ller, G. Angew. Chem. 1989, 101, 206; Angew. Chem.,
Int. Ed. Engl. 1989, 28, 203. (f) Zybill, C.; Mu¨ller, G. Organometallics
1988, 7, 1368. (g) Zybill, C. Nachr. Chem., Tech. Lab. 1989, 37, 248.
(h) Handwerker, H.; Parl, M.; Blu¨mel, J .; Zybill, C., Angew. Chem.,
Int. Ed. Engl. 1993, 32, 1313.
(13) (a) Zybill, C. Top. Curr. Chem. 1992, 160, 1. (b) Zybill, C.;
Handwerker, H.; Friedrich, H. Adv. Org. Chem. 1994, 36, 229. (c)
Zybill, C.; Liu, C. Y. Synlett 1995, 7, 687.

3302 Organometallics, Vol. 17, No. 15, 1998
Weinmann et al.
F igu r e 1. 1H NMR spectrum of (C6H4CH2NMe2-2)(H2CdCH)SidCr(CO)5 (13).
dynamic at 25 °C.7 This behavior is different from that
of 13 and can be explained by the fact that the H2Cd
CH group in 13 is a weaker π-donor toward the silicon
atom.
The IR data in the ν(CO) region for compounds 5, 14,
15, 22, and 23 are in agreement with the trigonal-
bipyramidal coordination sphere around the iron center.
The appearance of three absorption bands in the region
1880-2030 cm-1 verifies that the silanediyl unit oc-
cupies an axial position of the trigonal-bipyramidal-
coordinated iron atom. This is in good agreement with
theoretical studies, in which ligands with a higher donor
to acceptor ratio than that of CO are always bonded in
an axial position in LFe(CO)4 complexes.14-16
In 4, 7, 9, 11, 13, and 21 two very strong ν(CO)
absorptions between 1880 and 1960 cm-1 and one
medium band in the region of 2020-2070 cm-1 are
found. The appearance of two frequencies for the E
vibration can be explained by decreasing the local C4v
symmetry of the Cr(CO)5 moiety.17,18 For 18 two typi-
cally very strong vibrations are found at 1818 and 1892
cm-1 for the CO entities.18,19
X-ray structure determinations on selected examples
of the synthesized compounds verify the molecular
structures of the inter- and intramolecular donor-
stabilized silanediyl compounds, as already proposed
from spectroscopic data. The structures of (C6H4CH2-
NMe2-2)(Cl)SidCr(CO)5 (4) and (C6H4CH2NMe2-2)-
[P(C6H5)2]SidCr(CO)5 (11) are shown in Figure 2, while
the molecular structure of the acyclic heterobutadienes
(C6H4CH2NMe2-2)(H2CdCH)SidFe(CO)4 (14) and
[(C6H5)HCdCH](C6H5)SidFe(CO)4‚OP(NMe2)3 (23) are
(14) (a) Rossi, A. R.; Hoffmann, R. Inorg. Chem. 1975, 14, 365. (b)
Elian, M.; Hoffmann, R. Inorg. Chem. 1975, 14, 1058.
(15) (a) Kilbourn, B. T.; Reaburn, U. A.; Thompson, D. T., J . Chem.
Soc. A 1969, 1906. (b) Pickardt, J .; Ro¨sch. L.; Schumann, H. J .
Organomet. Chem. 1976, 107, 241.
(16) Lang, H.; Zsolnai, L.; Huttner, G. J . Organomet. Chem. 1985,
282, 23 and literature cited therein.
F igu r e 2. ORTEP drawings (drawn at the 50% probability
level) of the silanediyl complexes 4 (top) and 11 (bottom)
with the atom-numbering schemes.
presented in Figure 3. Crystallographic parameters and
selected geometrical details are listed in Tables 2-6.
Compound 4 crystallizesswith tetrahydrofuran as
solvent moleculesin the orthorhombic space group Pnna
(17) Strohmeier, W.; Mu¨ller, F. J . Chem. Ber. 1967, 100, 2812.
(18) Cotton, F. A.; Kraihanzel, C. S. J . Am. Chem. Soc. 1962, 84,
4432.
(19) Lang, H.; Mohr, G.; Scheidsteger, O.; Huttner, G. Chem. Ber.
1985, 118, 574 and literature cited therein.

Silanediyl Complex Chemistry
Organometallics, Vol. 17, No. 15, 1998 3303
the equatorial Cr-CCO distances (4, Cr-CCOeq - Cr-
CCOax ) 0.011 Å, 11, Cr-CCOeq - Cr-CCOax ) 0.025 Å;
Tables 3 and 4). A further noticeable feature of com-
pounds 4 and 11 is that the Si1-N1 bond lengths at
1.938(5) Å (4) (Table 3) and 1.996(2) (11) Å (Table 4)
are shorter than those found in pentacoordinated dichlo-
rosilanes such as (C6H4CH2NMe2-2)(R)SiCl2 (R ) singly
bonded organic ligand), in which the CH2NMe2 built-in
arm is datively bonded to a silicon atom1a and negligibly
elongated compared to covalent silicon-nitrogen bonds
in hypervalent silane compounds.21 The silicon-
nitrogen distances are additionally clearly affected by
the different ligands Cl and (C6H5)2P. In comparison
with the chlorine atom in 4, the more strongly electron-
donating (C6H5)2P group in 11 results in a longer Si-N
bond. Due to the dative nitrogen coordination, the
silicon atoms in molecules 4 and 11 show a distorted-
tetrahedral environment.
Compounds 14 and 23 crystallize in the orthorhombic
space group Pna21 (14) and monoclinic space group
P21/n (23). For 14 and 23 a distorted-tetrahedral
arrangement around the silicon atom is found in which
the (C6H4CH2NMe2-2)(H2CdCH)Si (14) and (C6H5HCd
CH)(C6H5)Si entities (23) occupy an apical position in
the coordination sphere of the Fe(CO)4(L) moiety (L )
silanediyl fragment). The bond angles around the
silicon atom in both compounds (14, Fe-Si-C11 )
120.5(1)°, Fe-Si-C15 ) 117.4(1)°, Fe-Si-N ) 118.7-
(1)°, N-Si-C15 ) 98.9(1)°; 23, Fe1-Si1-C5 ) 117.5-
(1)°, Fe1-Si1-C18 ) 115.8(1)°, Fe1-Si1-O5 ) 109.7-
(1)°, O5-Si1-C5 ) 102.9(1)°) indicate that the silicon
atom shows an almost trigonal-planar environment,
which is typical for intra- and intermolecular donor-
stabilized silanediyl compounds and arises from steric
interactions of the ligands at the silicon atom with the
metal-bonded carbonyl groups.12 The atoms Fe1, Si1,
C5, and C6 in 23, which form the heterobutadiene
framework, are in-plane bonded (maximum deviation
0.026 Å) (Figure 3). The silicon-iron moiety and the
carbon-carbon unit are thereby in a cisoid configura-
tion, and the bond lengths observed in these moieties
show the typical behavior expected for butadienes and
heterobutadienes. However, in compound 14 the het-
erobutadiene building block H2CdCH-SidFe is not
arranged in a cisoid configuration and the atoms which
form the 1-ferra-2-sila-1,3-diene are out-of-plane bonded
(Fe-Si-C15/Si-C15-C16 ) 135.6°). The SidFe bond
lengths at 2.265(1) Å in 14 and 2.280(1) Å in 23 are
similar to those found in other donor-stabilized si-
lanediyl complexes of type R2SidFe(CO)4 (R ) Cl, CH3,
OtBu, StBu).12 The Si-O distance at 1.726(2) Å in 23
implies a weak interaction between the silicon and
oxygen atoms and is significantly elongated as compared
to covalent Si-O bonds.22 The Si-N bond distance in
14 at 1.955(3) Å is identical with those observed in 4
and 11 and points to a partially covalent bonding
situation between these two atoms.
F igu r e 3. ORTEP drawings (drawn at the 50% probability
level) of the 1-ferra-2-sila-1,3-diene compounds 14 (top) and
23 (bottom) with the atom-numbering schemes.
and compound 11 in the monoclinic space group P21/n.
In these complexes the geometrical environment around
the chromium center is fixed by the arrangement of the
five carbonyl ligands and the silanediyl moiety (C6H4-
CH2NMe2-2)(R)Si. The latter unit is bonded to the
octahedral chromium atom with a short Cr-Si bond
length (4, 2.335(2) Å; 11, 2.406(1) Å; Tables 3 and 4),
implying a multiple bonding character between these
two atoms.6-13 Moreover, ab initio calculations for the
Cr-Si bond reinforce this observation.20 The difference
in the Cr-Si bond lengths in 4 and 11 can best be
explained by electronic effects: the (C6H5)2P group in
11 is a stronger donor ligand, as compared with the
chlorine atom in 4. This results in a higher electron
density at the silanediyl unit, which finally leads to a
weakening of the Cr-Si bond and points to a decreasing
back-donation from the chromium center to the silicon
atom. This finding is nicely reflected in the differences
between the axial Cr-CCO distance and the average of
(21) Weinmann, M.; Walter, O.; Huttner, G.; Lang, H. J . Organomet.
Chem., in press.
(20) (a) Nakatsuji, H.; Ushio, J .; Yonezawa, T. J . Organomet. Chem.
1983, 258, C1. (b) J acobsen, H.; Ziegler, T. Organometallics 1995, 14,
224.
(22) For an overview see: Sheldrick, W. S. In The Chemistry of
Organic Silicon Compounds; Patai, S., Rappoport, Z., Eds.; Wiley: New
York, 1989.

3304 Organometallics, Vol. 17, No. 15, 1998
Ta ble 2. X-r a y Diffr a ction Da ta for Com p ou n d s 4, 11, 14, a n d 23
Weinmann et al.
4
11
14
23
formula
fw
C
16H16ClCrNO5.5Si
C26H22CrNO5PSi
539.51
C15H15FeNO4Si
357.22
C24H30FeN3O5PSi
555.42
425.84
cryst syst
space group
orthorhombic
Pnna
monoclinic
P21/n
orthorhombic
Pna21
monoclinic
P21/n
a (Å)
b (Å)
c (Å)
11.53(1)
28.219(3)
11.781(4)
9.637(2)
16.371(4)
10.824(4)
9.320.3
11.647(5)
14.911(6)
16.131(7)
100.62(3)
2753(5)
26.217(6)
10.316(2)
101.03(2)
2558.2(9)
4
â (deg)
V (Å3)
3883(4)
8
1651(5)
4
Z
4
cryst dimens (mm)
density (calcd) (g cm-3
diffraction model
0.20 × 0.20 × 0.30
0.20 × 0.25 × 0.25
0.20 × 0.30 × 0.30
0.20 × 0.20 × 0.20
)
1.476
1.401
1.437
1.340
Siemens (Nicolet)
R3m/V
Siemens (Nicolet)
R3m/V
Siemens (Nicolet)
R3m/V
Siemens (Nicolet)
R3m/V
radiation (Å)
scan type
Mo KR, λ ) 0.710 73
Mo KR, λ ) 0.710 73
Mo KR, λ ) 0.710 73
Mo KR, λ ) 0.710 73
ω scan
5 e 2ω˘ e 29.3
0.6
ω scan
ω scan
ω scan
scan rate (deg min-1
scan range (deg)
2Θ range (deg)
)
5.3 e 2ω˘ e 29.3
0.65
4.3-49.1
-10 to +10, -21 to
+30, -12 to +11
0
5 e 2ω˘ e 29.3
0.6
6.3-56.1
-9 to +21, -7 to
+14, -12 to +12
0
2.3 e 2ω˘ e 29.3
0.75
2.9-48.1
0-13, 0-32,
0-13
3.8-52.0
0-12, 0-18, -19 to
+19
data range (h, k, l)
total decay
0
0
temp (K)
200
220
200
205
no. of data collected
3006
4477
2111
4984
no. of data with I g 2σ(I)
no. of params refined
2010
233
3261
318
1850
259
3739
436
min/max residual electron
+0.646/-0.392
+0.306/-0.199
+0.405/-0.256
+0.343/-0.257
density (e Å-3
)
Mo KR linear abs coeff
0.827
0.593
1.001
0.687
(mm-1
)
R1 (I g 2σ(I)/all)a
0.0532/0.0899
0.1254/0.1446
0.0383/0.0590
0.0843/0.0905
0.0308/0.0396
0.0709/0.0743
0.0351/0.0521
0.0867/0.0927
wR2 (I g 2σ(I)/all)b
R1 ) ∑|Fo - Fc|/∑Fc. wR2 ) [∑w(Fo - Fc2)]2/[∑w(Fo2)]2.
a
b
2
Ta ble 3. Selected Bon d Len gth s (Å) a n d An gles
(d eg) of Com p ou n d 4a
Ta ble 4. Selected Bon d Len gth s (Å) a n d An gles
(d eg) of Com p ou n d 11a
Bond Lengths
Bond Lengths
Si1-Cr1 2.335(2) Cr1-C3 1.880(6) O4-C4
1.141(6)
1.141(6)
Si1-Cr1 2.406(1) Cr1-C1 1.870(3) O4-C4
1.142(3)
1.145(3)
Si1-C6
Si1-N1
1.874(5) Cr1-C4 1.881(6) O5-C5
Si1-C6
Si1-N1
Si1-P1
P1-C15
P1-C21
Cr1-C5
1.887(3) Cr1-C2 1.875(3) O5-C5
1.938(5) Cr1-C5 1.877(6) N1-C12 1.511(7)
1.996(2) Cr1-C4 1.891(3) N1-C13 1.496(3)
2.294(1) Cr1-C3 1.904(3) N1-C14 1.502(3)
Si1-Cl1 2.125(2) O1-C1
1.131(7) N1-C13 1.485(7)
1.134(6) N1-C14 1.500(7)
1.143(6)
Cr1-C1
Cr1-C2
1.880(6) O2-C2
1.885(6) O3-C3
1.837(3) O1-C1
1.834(3) O2-C2
1.860(3) O3-C3
1.153(3) N1-C12 1.506(3)
1.144(3)
1.141(3)
Bond Angles
172.1(2)
C1-Cr1-Si1
C5-Cr1-Si1
C3-Cr1-Si1
C4-Cr1-Si1
C2-Cr1-Si1
C6-Si1-N1
C6-Si1-Cl1
N1-Si1-Cl1
C6-Si1-Cr1
N1-Si1-Cr1
Cl1-Si1-Cr1
C14-N1-C13
C14-N1-C12
C13-N1-C12
C14-N1-Si1
C13-N1-Si1
C12-N1-Si1
122.6(2)
116.5(1)
110.2(5)
108.0(4)
111.0(4)
107.9(3)
113.5(4)
105.9(3)
Bond Angles
83.0(2)
88.8(2)
86.7(2)
95.7(2)
87.2(2)
99.4(2)
96.4(2)
127.3(2)
C1-Cr1-Si1
C2-Cr1-Si1
C3-Cr1-Si1
C4-Cr1-Si1
C5-Cr1-Si1
C15-P1-C21
C15-P1-Si1
C21-P1-Si1
C6-Si1-N1
C6-Si1-P1
87.5(1)
N1-Si1-P1
96.0(1)
121.3(1)
121.0(1)
125.8(1)
108.9(2)
107.9(2)
108.1(2)
104.9(2)
116.6(2)
110.1(2)
86.0(1)
96.5(1)
87.7(1)
176.1(1)
103.6(1)
96.4(1)
109.3(1)
85.3(1)
97.9(1)
C6-Si1-Cr1
N1-Si1-Cr1
P1-Si1-Cr1
C13-N1-C12
C13-N1-C14
C14-N1-C12
C12-N1-Si1
C13-N1-Si1
C14-N1-Si1
a
Standard deviations in units of the last significant figure are
given in parentheses.
a
Standard deviations in units of the last significant figure are
given in parentheses.
Exp er im en ta l Section
Gen er a l Com m en ts. All reactions were carried out under
an atmosphere of nitrogen using standard Schlenk techniques.
Solvents were purified and dried by distillation. n-Pentane,
n-hexane, and dichloromethane were dried over calcium hy-
dride. Diethyl ether and tetrahydrofuran were refluxed with
sodium/benzophenone ketyl, distilled, and saturated with
nitrogen. Chlorosilanes were freshly crystallized or distilled
from magnesium and stored over magnesium at 0 °C. Na2-
[Fe(CO)4]and K2[Cr(CO)5] were synthesized according to the
literature.23,24 Glassware was dried at 300 °C/10-3 mbar before
use. Infrared spectra were recorded with a Perkin-Elmer 983G
spectrometer (KBr pellets or solutions in CaF2 cells). 1H NMR
spectra were recorded on a Bruker AC 200 spectrometer,
operating at 200.132 MHz (internal standard: CDCl3, δ 7.27;
C6D6, δ 7.16; (CD3)2SO, δ 2.50) in the Fourier transform mode,
13C{1H} NMR spectra (internal standard: CDCl3, δ 77.0; C6D6,
δ 126; CD2Cl2, δ 53.8) were recorded at 50.323 MHz, 29Si NMR
spectra (external standard: SiMe4, δ ) 0, recorded in CDCl3,
C6D6, or tetrahydrofuran/D2O) at 39.763 MHz, and 31P{1H}
NMR spectra (external standard: 85% H3PO4 with P(OMe)3,
δ 139, recorded in CDCl3 or C6D6) at 81.015 MHz. Chemical
shifts are reported in δ units (parts per million) downfield from
the standards used with the solvent as the reference signal.
FD and EI mass spectra were recorded on a Finnigan 8400
(23) Collman, J . P.; Finke, R. G.; Cawse, J . N.; Braumann, J . I. J .
Am. Chem. Soc. 1977, 99, 2515.
(24) Schwindt, M. A.; Lejon, T.; Hegedus, L. S. Organometallics
1990, 9, 2814.

Silanediyl Complex Chemistry
Organometallics, Vol. 17, No. 15, 1998 3305
Ta ble 5. Selected Bon d Len gth s (Å) a n d An gles
(d eg) of Com p ou n d 14a
-30 °C afforded 4 as yellow cubes. Yield: 9.6 mmol (3.74 g,
53%, based on 1). The obtained spectroscopic data of 4 are in
agreement with the data published in ref 8.
Bond Lengths
2. [C6H4CH2N(CH3)2-2](Cl)SidF e(CO)4, [[2-((Dim eth y-
la m in o)m et h yl)p h en yl]ch lor osila n ed iyl]ir on (0) Tet r a -
ca r bon yl (5). A 9.0 mmol (2.4 g) amount of [C6H4CH2N-
(CH3)2-2]SiCl3 (1)7 dissolved in 150 mL of diethyl ether was
added dropwise to a suspension of 9.0 mmol (1.93 g) of Na2-
[Fe(CO)4] (2) in 200 mL of diethyl ether at -70 °C. The
reaction mixture was warmed to 25 °C overnight and then
filtered through a pad of Celite. The filtrate was concentrated
to 30%, 50 mL of n-pentane was added, and the resulting deep
red solution was slowly cooled to -30 °C. From this solution
complex 5 precipitated as a reddish amorphous solid.
Si-Fe
2.265(1) Fe-C3
1.770(4) N-C12
1.503(4)
1.494(4)
1.493(4)
Si-C15 1.869(3) Fe-C4
1.781(4) N-C13
Si-C11 1.864(3) O1-C1 1.140(4) N-C14
Si-N
Fe-C1
Fe-C2
1.955(3) O2-C2 1.140(4) C15-C16 1.305(6)
1.784(3) O3-C3 1.142(5)
1.787(4) O4-C4 1.139(4)
Bond Angles
C1-Fe-Si
C2-Fe-Si
C3-Fe-Si
C4-Fe-Si
N-Si-Fe
C11-Si-Fe
C11-Si-N
C11-Si-C15
C15-Si-Fe
89.5(1)
175.9(1)
83.2(1)
C15-Si-N
C12-N-Si
C12-N-C13
C12-N-C14
C13-N-Si
C13-N-C14
C14-N-Si
C16-C15-Si
98.9(1)
105.0(2)
109.5(3)
108.6(3)
114.3(2)
108.0(3)
111.3(2)
124.3(3)
85.0(1)
118.7(1)
120.5(1)
88.1(1)
108.0(2)
117.4(1)
Yield: 4.38 mmol (1.60 g, 49% based on 1). Mp: 160 °C dec.
Anal. Calcd for C13H12O4NClFeSi (365.63): C, 42.70; H, 3.31.
Found: C, 42.76; H, 3.51. IR (KBr): νCO 2032 (s), 1985 (vs,
br), 1911 (vs, br) cm-1 1H NMR ((CD3)2SO): δ 2.50 (br, 3 H,
.
CH3); 2.70 (br, 3 H, CH3); 4.45 (d, 2J HH ) 15.0 Hz, 1 H, CH2);26
7.20-8.05 (m, 4 H, C6H4). 13C{1H} NMR (CD2Cl2): δ 46.9
(CH3); 48.2 (CH3); 67.8 (CH2); 122.4, 129.3, 131.9, 133.1, 138.0,
139.5 (C6H4); 214.8 (CO). EI-MS (m/z (relative intensity)): M+,
365 (19); M+ - CO, 337 (22); M+ - 2 CO, 309 (10); M+ - 3
CO, 281 (35); M+ - 4 CO, 253 (100); [C6H4CH2N(CH3)2]Si+,
162 (77); C6H4CH2NCH3+, 119 (30).
3. [C6H4CH2N(CH3)2-2](CH3)SidCr (CO)5, [[2-((Dim eth -
yla m in o)m et h yl)p h en yl]m et h ylsila n ed iyl]ch r om iu m -
(0) P en ta ca r bon yl (7).9 An 8.0 mmol (5 mL) amount of a
1.6 M CH3Li solution in diethyl ether was diluted with 200
mL of tetrahydrofuran and at -70 °C cautiously added to 8.0
mmol (3.1 g) of [C6H4CH2N(CH3)2-2](Cl)SidCr(CO)5 (4) dis-
solved in 250 mL of tetrahydrofuran. The reaction mixture
was warmed to 25 °C over 3 h with vigorous stirring. After
additional stirring for 3 h at 25 °C all volatile components were
evaporated with vacuum and the brown residue was extracted
with four 50 mL portions of dichloromethane. The combined
phases were concentrated to 30%, and 40 mL of n-pentane was
added. From the obtained solution complex 7 crystallized as
yellow cubes at -30 °C. Yield: 5.4 mmol (2.0 g, 68%, based
on 4). The spectroscopic as well as experimental data of 7 are
published in ref 9.
a
Standard deviations in units of the last significant figure are
given in parentheses.
Ta ble 6. Selected Bon d Len gth s (Å) a n d An gles
(d eg) of Com p ou n d 23a
Bond Lengths
Si1-Fe1
Si1-C5
Si1-C18
Si1-O5
Fe-C1
2.280(1) Fe-C3
1.871(3) Fe-C4
1.884(3) O1-C1
1.726(2) O2-C2
1.772(3) O3-C3
1.770(3) O4-C4
1.782(3) P1-O5
1.771(3) P1-N1
1.152(3) P1-N2
1.156(3) P1-N3
1.149(3)
1.535(2)
1.619(3)
1.623(3)
1.619(3)
Fe-C2
1.156(3)
Bond Angles
C1-Fe1-Si1
C2-Fe1-Si1
C3-Fe1-Si1
C4-Fe1-Si1
Fe1-Si1-C5
Fe1-Si1-C18
Fe1-Si1-O5
O5-Si1-C5
85.9(1)
84.5(1)
178.3(1)
83.4(1)
117.5(1)
115.8(1)
109.7(1)
102.9(1)
O5-Si1-C18
C5-Si1-C18
Si1-O5-P1
O5-P1-N1
O5-P1-N2
O5-P1-N3
Si1-C5-C6
C5-C6-C12
103.6(1)
105.9(1)
146.8(1)
108.6(1)
114.8(1)
104.3(1)
126.6(2)
127.5(3)
a
Standard deviations in units of the last significant figure are
given in parentheses.
4. [C6H4CH2N(CH3)2-2](C6H5)SidCr (CO)5, [[2-((Dim eth -
yla m in o)m eth yl)p h en yl]p h en ylsila n ed iyl]ch r om iu m (0)
P en ta ca r bon yl (9).9,10 To 4.1 mmol (1.6 g) of [C6H4CH2N-
(CH3)2-2](Cl)SidCr(CO)5 (4) dissolved in 50 mL of tetrahydro-
furan was added 4.1 mmol (2.3 mL) of 1.8 M C6H5Li (8) diluted
with 30 mL of tetrahydrofuran at -50 °C. After the reaction
mixture was warmed to 25 °C, all volatile components were
removed in vacuo and the residual brownish oil was treated
with 100 mL of dichloromethane for 10 min in an ultrasonic
bath. The obtained suspension was filtered through a pad of
Celite, and the solvent was evaporated at 25 °C/10-1mbar.
Crystallization from tetrahydrofuran/n-pentane (10:1) at -30
°C yielded 9 as yellow cubes. Yield: 2.32 mmol (1.0 g, 57%
based on 4). The spectroscopic and analytical data of 9 are
published in ref 10.
5. [C6H4CH2N(CH3)2-2][P (C6H5)2]SidCr (CO)5, [[2-((Di-
m e t h y la m in o )m e t h y l)p h e n y l](d ip h e n y lp h o s p h in o )-
sila n ed iyl]ch r om iu m (0) P en ta ca r bon yl (11). At -30 °C
2.27 mmol (1.4 mL) of 1.6 M CH3Li was added in one portion
to 2.27 mmol (425 mg) of HP(C6H5)2, dissolved in 30 mL of
diethyl ether. Carefully warming the reaction mixture to 25
°C yielded a deep red solution of LiP(C6H5)2 (10), which was
added dropwise to 2.27 mmol (885 mg) of [C6H4CH2N(CH3)2-
2](Cl)SidCr(CO)5 (4) at -70 °C. Warming the reaction mix-
ture to 25 °C led to a change in color at -35 °C from orange to
pale green. After the mixture was stirred for 2 h at 25 °C, all
mass spectrometer, operating in the positive ion mode. Melt-
ing points were determined using analytically pure samples,
sealed off in nitrogen-purged capillaries on a Gallenkamp MFB
595 010 M melting point apparatus. Photochemical reactions
were performed with a 400 W medium-pressure mercury lamp
in a water-cooled quartz reaction vessel under a steady stream
of nitrogen. Microanalyses were performed by the Organisch-
Chemisches Institut der Universita¨t Heidelberg.
1. [C6H4CH2N(CH3)2-2](Cl)SidCr (CO)5, [[2-((Dim eth y-
la m in o)m et h yl)p h en yl]ch lor osila n ed iyl]ch r om iu m (0)
P en ta ca r bon yl (4).8 A 360 mmol (4.3 g) portion of graphite
was heated to 300 °C/10-3 mbar for 30 min and then cooled to
25 °C. A 36.36 mmol (1.42 g) amount of K was added, and
the mixture was slowly heated to 160 °C and held at this
temperature for 10 min. In a strongly exothermic reaction the
25
gold-yellow intercalation compound KC8 was formed, which
then was cooled to -70 °C; 20 mL of tetrahydrofuran was
added. An 18.18 mmol (4.4 g) amount of Cr(CO)6 was added
in one portion, and the reaction mixture was warmed to 25 °C
overnight. The green slurry obtained was cooled to -70 °C,
and a solution of 18.18 mmol (4.84 g) of [C6H4CH2N(CH3)2-2]-
SiCl3 (1)7 was added dropwise. The reaction mixure was
stirred at this temperature for 6 h and then slowly warmed to
25 °C and filtered through a pad of Celite. The filtrate was
concentrated to 30% and treated with n-hexane until the
precipitation of a yellow solid was observed. Slow cooling to
(26) One of the resonance signals of the diastereotopic methylene
portons is masked by the resonance signal of the solvent d6-DMSO
and can therefore not be assigned clearly.
(25) Fu¨rstner, A. Angew. Chem. 1993, 105, 171; Angew. Chem., Int.
Ed. Engl. 1993, 32, 164 and literature cited therein.

3306 Organometallics, Vol. 17, No. 15, 1998
Weinmann et al.
volatile materials were removed under vacuum and the yellow
oily residue was extracted four times with 30 mL portions of
dichloromethane. The obtained yellow solution was filtered
through a pad of Celite, and dichloromethane was distilled off
at 25 °C. Crystallization of the remaining solid produced
complex 11 as yellow crystals.
NMR (Et2O/D2O): δ 116.8. EI-MS (m/z (relative intensity)):
M+, 357 (21); M+ - CO, 329 (11); M+ - 2 CO, 301 (19); M+
-
3 CO, 273 (11); M+ - 4 CO, 245 (100); M+ - 4CO - C2H3, 219
(16); C6H4CH2NCH3+, 119 (21).
8. [C6H4CH2N(CH3)2-2](CH3)SidF e(CO)4, [[2-((Dim eth -
yla m in o)m eth yl)p h en yl]m eth ylsila n ed iyl]ir on (0) Tetr a -
ca r bon yl (15).10a A 4.8 mmol (3.0 mL) amount of a 1.6 M
CH3Li solution in diethyl ether was diluted with 100 mL of
diethyl ether, and at -30 °C this mixture was slowly added
to a solution of 4.8 mmol (1.8 g) of [C6H4CH2N(CH3)2-2](Cl)-
SidFe(CO)4 (5) in 100 mL of diethyl ether. The pale red
reaction mixture was slowly warmed to 25 °C, filtered through
a pad of Celite, and concentrated to 30%. A 30 mL portion of
n-pentane was added, and the solution was cooled to -30 °C.
[C6H4CH2N(CH3)2-2](CH3)SidFe(CO)4 (15) was obtained as a
pale red solid. Yield: 3.8 mmol (1.3 g, 80%, based on 5). The
spectroscopic and analytical data of 15 are published in ref
10a.
9. [C6H4CH2N(CH3)2-2](CH3)SidCr (CO)5, [[2-((Dim eth -
yla m in o)m et h yl)p h en yl]m et h ylsila n ed iyl]ch r om iu m -
(0) P en ta ca r bon yl (7), by P h otoch em ica l Rea ction of
[C6H4CH2N(CH3)2-2](CH3)SiH2 (16) w ith Cr (CO)6 (17a ). A
1.5 mmol (330 mg) amount of Cr(CO)6 was dissolved in 200
mL of diethyl ether and transferred to a photochemical reactor.
A 1.5 mmol (270 mg) amount of [C6H4CH2N(CH3)2-2](CH3)-
SiH2 (16)21 was added in one portion, and the mixture was
irradiated for 3 h at 5 °C. Afterward the reaction mixture was
cooled to 0 °C and held there for 3 days to crystallize unreacted
Cr(CO)6. Thereafter the reaction mixture was filtered through
a pad of Celite. A 20 mL portion of n-pentane was added, and
7 was obtained at -30 °C as yellow crystals. Yield: 0.66 mmol
(240 mg, 44%, based on 7). The spectroscopic and analytical
data of 7 are published in ref 9.
Yield: 0.62 mmol (335 mg, 27%, based on 4). Mp: 168 °C.
Anal. Calcd. for C26H22O5NPCrSi (539.52): C, 57.88; H; 4.11.
Found: C, 57.50; H, 4.58. IR (CH2Cl2): νCO 2067 (s), 1934 (vs,
vbr) cm-1 1H NMR (CDCl3): δ 2.89 (s, 3 H, CH3); 3.25 (s, 3
.
2
2
H, CH3); 3.81 (d, J HH ) 13.9 Hz, 1 H, CH2); 4.90 (d, J HH
)
13.9 Hz, 1 H, CH2); 7.16-8.00 (m, 14 H, C6H4 and C6H5). 13C-
{1H} NMR (CDCl3): δ 45.2 (CH3); 63.5 (CH2); 128.2-134.6
3
3
(C6H4 and C6H5); 216.2 (d, J PC ) 12.0 Hz, CO); 221.1 (d, J PC
) 5.8 Hz, CO). 31P{1H} NMR (CDCl3): δ 31.1. EI-MS (m/z
(relative intensity)): M+, 539 (3); M+ - 4 CO, 427 (31); M+
-
4 CO - HP(C6H5)2, 238; M+ - Cr(CO)5 - P(C6H5)2, 186 (26).
6. [C6H4CH2N(CH3)2-2](H2CdCH)SidCr (CO)5, [[2-((Dim -
et h yla m in o)m et h yl)p h en yl]vin ylsila n ed iyl]ch r om iu m -
(0) P en ta ca r bon yl (13). A 4.0 mmol (4.0 mL) amount of 1.0
M (H2CdCH)MgBr (12) in tetrahydrofuran was slowly added
to 4.0 mmol (1.56 g) of [C6H4CH2N(CH3)2-2](Cl)SidCr(CO)5 (4)
dissolved in 100 mL of tetrahydrofuran at -50 °C. After the
reaction mixture was warmed to 25 °C, all volatiles were
removed in vacuo and the oily residue was extracted with four
50 mL portions of dichloromethane. The combined extracts
were filtered through a pad of Celite, and dichloromethane was
distilled off. Crystallization of the obtained powder from
tetrahydrofuran/n-pentane (5:1) at -30 °C yielded 13 as yellow
cubes.
Yield:1.86 mmol (0.71 g, 47%, based on 4). Mp: 124 °C dec.
Anal. Calcd for C16H15O5NCrSi (381.39): C, 50.39; H, 3.96.
Found: C, 49.90; H, 3.99. IR (KBr): νCH 3054 (w), 2997 (w),
2944 (w); νCO 2036 (m), 1960 (sh), 1899 (vs, vbr); νCdC 1580
10. [C6H4CH2N(CH3)2-2](CH3)SidF e(CO)4, [[2-((Dim e-
th yla m in o)m eth yl)p h en yl]m eth ylsila n ed iyl]ir on (0) Tet-
r a ca r bon yl (15), by P h otoch em ica l Rea ction of [C6H4-
CH2N(CH3)2-2](CH3)SiH2 (16) w ith F e(CO)5 (17b). A 1.5
mmol (290 mg) amount of Fe(CO)5 and 1.5 mmol (270 mg) of
[C6H4CH2N(CH3)2-2](CH3)SiH2 (17) were dissolved in 200 mL
of diethyl ether and irradiated in a quartz vessel for 3 h at 0
°C under a steady flow of nitrogen. During irradiation the
color of the reaction mixture changed from yellow to dark
brown. After filtration through a pad of Celite, all volatiles
were removed under vacuum and the red oily residue was
dissolved in 40 mL of dichloromethane/n-pentane (10:1).
Crystallization at -30 °C gave 15 as a red-brown microcrys-
talline solid. Yield: 1.0 mmol (350 mg, 66%, based on 17).
The spectroscopic and analytical data of 15 are published in
ref 10a.
(w) cm-1 1H NMR (CDCl3): δ 2.84 (s, 3H, CH3); 2.96 (s, 3H,
.
2
2
CH3); 3.90 (d, J HH ) 13.7 Hz, 1 H, CH2); 4.46 (d, J HH ) 13.7
2
3
Hz, 1 H, CH2); 5.12 (dd, J HH ) 3.4 Hz, J HH ) 19.8 Hz, 1 H,
C2H3); 5.85 (dd, J HH ) 3.4 Hz, J HH ) 14.0 Hz, 1 H, C2H3);
2
3
3
3
6.69 (dd, J HH ) 14.0 Hz, J HH ) 19.8 Hz, 1 H, C2H3); 7.22-
7.27 (m, 1 H, C6H4); 7.39-7.43 (m, 2 H, C6H4); 7.88-7.92 (m,
1 H, C6H4. 13C{1H} NMR (CDCl3): δ 45.9 (CH3); 47.9 (CH3);
68.2 (CH2); 123.6, 128.4, 129.7, 131.2, 134.4, 139.4, 141.3, 141.5
(C2H3 and C6H4); 221.3 (CO); 225.5 (CO). 29Si{1H} NMR
(tetrahydrofuran/D2O): δ 114.9. EI-MS (m/z (relative inten-
sity)): M+, 381 (13); M+ - CO, 353 (6); M+ - 3 CO, 297 (11);
M+ - 4 CO, 269 (15); M+ -5 CO, 241 (100); C6H4CH2NCH3
,
+
119 (9).
7. [C6H4CH2N(CH3)2-2](H2CdCH)SidFe(CO)4, [[2-((Dim -
eth yla m in o)m eth yl)p h en yl]vin ylsila n ed iyl]ir on (0) Tet-
r a ca r bon yl (14). A 6.0 mmol (6.0 mL) amount of 1 M (H2Cd
CH)MgBr (12) in tetrahydrofuran was concentrated to 1.0 mL
and diluted with 200 mL of diethyl ether. At -30 °C the
obtained solution was slowly added to 6.0 mmol (2.2 g) of [C6H4-
CH2N(CH3)2-2](Cl)SidFe(CO)4 (5), dissolved in 100 mL of
diethyl ether. The reaction mixture was warmed to 25 °C over
3 h, filtered through a pad of Celite, and concentrated to 50%.
After 100 mL of n-pentane was added, [C6H4CH2N(CH3)2-2]-
(H2CdCH)SidFe(CO)4 (14) crystallized at -30 °C as reddish
cubes.
11.
[[2-((Dim eth yla m in o)m eth yl)p h en yl]m eth ylsila n ed iyl]-
(η5-cyclop en ta d ien yl)m a n ga n ese(I) Dica r bon yl (18).
[C6H 4CH 2N(CH 3)2-2](CH 3)SidMn (η5-C5H 5)(CO)2,
A
1.95 mmol (350 mg) amount of [C6H4CH2N(CH3)2-2](CH3)SiH2
(16) and 1.95 mmol (400 mg) of (η5-C5H5)Mn(CO)3 (17c) were
dissolved in 300 mL of diethyl ether and irradiated in a quartz
vessel for 3 h at 0 °C. The brown solution was filtered through
a pad of Celite, and the filtrate was concentrated to 50 mL.
After 10 mL of n-pentane was added at -30 °C, [C6H4CH2N-
(CH3)2-2](CH3)SidMn(η5-C5H5)(CO)2 (19) was obtained as an
amorphous solid, which is extremely sensitive to air.
Yield: 2.3 mmol (0.8 g, 38% based on 5). Mp: 85 °C dec.
Anal. Calcd for C15H15O4NFeSi (357.23): C, 50.44; H, 4.23;
N, 3.92. Found: C, 49.96; H, 4.50; N, 3.92. IR (KBr): νCO
Yield: 0.7 mmol (250 mg, 36%, based on 17). Anal. Calcd.
for C17H20NO2MnSi (353.38): C, 57.78; H, 5.70. Found: C,
55.35; H, 5.68 (due to the high instability of 18, only poor
elemental analyses could be obtained). IR (CHCl3): νCO 1892
1996 (vs, br), 1932 (m), 1879 (s) cm-1
.
1H NMR (C6D6): δ 1.99
2
(s, 3 H, CH3); 2.02 (s, 3 H, CH3); 2.75 (d, J HH ) 14.4 Hz, 1 H,
2
2
(vs), 1818 (vs) cm-1
.
1H NMR (CDCl3): δ 0.65 (s, 3 H, SiCH3);
CH2); 3.36 (d, J HH ) 14.4 Hz, 1 H, CH2); 5.62 (dd, J HH ) 3.6
3
2
3
2
Hz, J HH ) 19.5 Hz, 1 H, C2H3); 5.84 (dd, J HH ) 3.6 Hz, J HH
2.71 (s, 3 H; NCH3); 2.90 (s, 3 H, NCH3); 3.99 (d, J HH ) 8.6
3
3
Hz, 1 H, CH2);27 4.47 (s, C5H5, 5 H); 7.19-7.33 (m, 3 H, C6H4);
) 13.9 Hz, 1 H, C2H3); 6.22 (dd, J HH ) 13.9 Hz, J HH ) 19.5
Hz, 1 H, C2H3); 6.67-6.72 (m, 1 H, C6H4); 7.06-7.16 (m, 2 H,
C6H4); 7.82-7.86 (m, 1 H, C6H4). 13C{1H} NMR (C6D6): δ 45.1
(CH3); 46.8 (CH3); 66.2 (CH2); 122.6, 128.0, 129.4, 133.4, 134.5,
136.1, 137.3, 138.2 (C2H3 and C6H4); 215.4 (CO). 29Si{1H}
(27) One of the resonance signals of the methylene protons is
presumably masked by the resonance signal of the cyclopentadienyl
protons.

Silanediyl Complex Chemistry
Organometallics, Vol. 17, No. 15, 1998 3307
7.64-7.67 (m, 1 H, C6H4). 13C{1H} NMR (CDCl3): δ 6.5
(SiCH3); 39.8 (NCH3); 48.6 (NCH3); 67.2 (CH2); 79.4 (C5H5);
122.9, 127.5, 128.1, 132.4, 137.1, 146.2 (C6H4) 233.2 (CO); 233.4
(CO). EI-MS (m/z (relative intensity)): M+, 353 (25); M+ - 2
CO, 297 (100); [C6H4CH2N(CH3)2](CH3)Si+, 176 (41); [C6H4-
CH2N(CH3)2]Si+, 162 (20).
12. [C6H 4CH 2N(CH 3)2-2](H 2CdCH)SidCr (CO)5, [[2-
((D im e t h y la m in o )m e t h y l)p h e n y l]v in y ls ila n e d iy l]-
ch r om iu m (0) P en ta ca r bon yl (13), fr om [C6H4CH2N-
(CH3)2-2](H2CdCH)SiCl2 (19) a n d K2[Cr (CO)5] (2). The
synthesis of complex 13 was carried out in a manner similar
to the synthesis of 4. Used quantities of the reactants: 18.2
mmol of K2[Cr(CO)5] (2) and 18.2 mmol (4.73) g of [C6H4CH2N-
(CH3)2-2](H2CdCH)SiCl2 (19).
15. (H2CdCH)(Cl)SidF e(CO)4‚OP [N(CH3)2]3 (22), [Vi-
n ylch lor osila n ed iyl]ir on (0) Tetr a ca r bon yl Hexa m eth -
ylp h osp h or ic Tr ia m id e. At -40 °C 13.16 mmol (2.12 g) of
(H2CdCH)SiCl3 dissolved in 50 mL of tetrahydrofuran were
added dropwise to a suspension of 13.16 mmol (2.81 g) of Na2-
[Fe(CO)4] (3) and 13.16 mmol (2.36 g) of [(CH3)2N]3PdO in 40
mL of tetrahydrofuran. The reaction mixture was slowly
warmed to 25 °C and after stirring for 3 h filtered through a
pad of Celite. After removal of all volatile components in
vacuo, the red residue was crystallized from 30 mL of tetrahy-
drofuran/n-hexane at -30 °C. Complex 22 was obtained as
red-brown crystals.
Yield: 4.8 mmol (2.1 g, 36%, based on (H2CdCH)SiCl3)).
Mp: 113 °C dec. Anal. Calcd for C12H21O5N3PClFeSi
(437.66): C, 32.93; H, 4.84. Found: C, 32.54; H, 4.99. IR
Yield: 7.8 mmol (2.96 g, 43%, based on 16). Spectroscopic
and analytical data: see synthesis of complex 13, reaction of
4 with 12 (section 6)).
(tetrahydrofuran): νCO 2020 (vs), 1935 (vs), 1906 (vs, br); νCdC
3
1600 (w) cm-1
.
1H NMR (C6D6): δ 2.22 (d, J PH ) 10.5 Hz,
13. [C6H4CH2N(CH3)2-2](H2CdCH)SidF e(CO)4, [[2-((Di-
m eth ylam in o)m eth yl)ph en yl]vin ylsilan ediyl]ir on (0) Tet-
r a ca r bon yl (14), fr om [C6H4CH2N(CH3)2-2](H2CdCH)SiCl2
(19) a n d Na 2[F e(CO)5] (3). The synthesis of compound 14
was carried out in a manner similar to the procedure described
for the synthesis of 5. Used quantities of the reactants: 9.0
mmol (1.93 g) of Na2[Fe(CO)4] (2) and 9.0 mmol (2.34) g of
[C6H4CH2N(CH3)2-2](H2CdCH)SiCl2 (16).
18H, CH3); 5.98-6.58 (m, 3H, C2H3). 13C{1H} NMR (C6D6): δ
2
37.3 (d, J PC ) 4.6 Hz, CH3); 132.3 (C2H3); 143.1 (C2H3); 217.1
(CO). 29Si{1H} NMR (C6D6): δ 75.8 (d, J PSi ) 30.3 Hz). 31P-
2
{1H} NMR (CDCl3): δ 22.23 (s).
16. [(C6H 5)CH dCH ](C6H 5)SidF e(CO)4‚OP [N(CH 3)2]3
(23), [ω-Styr ylph en ylsilan ediylir on (0) Tetr acar bon yl Hex-
a m eth ylp h osp h or ic Tr ia m id e. As in the preparation of
compound 22, 7.06 mmol (1.51 g) of Na2[Fe(CO)4] (3), 7.06
mmol (1.97 g) of [(C6H5)HCdCH](C6H5)SiCl2 (8a ), and 7.06
mmol (1.27 g) of [(CH3)2N]3PdO were reacted in 90 mL of
tetrahydrofuran at -40 °C. Crystallization from tetrahydro-
furan/n-hexane (10:1) produced 23 as red cubes.
Yield: 3.1 mmol (1.11 g, 35%, based on 16). Analytical and
spectroscopic data: see synthesis of 14, reaction of 5 with 12
(Section 7)).
14. (H2CdCH)(Cl)SidCr (CO)5‚OP [N(CH3)2]3 (21), [Vi-
n ylch lor osila n ed iyl]ch r om iu m (0) P en ta ca r bon yl Hex-
a m eth ylp h osp h or ic Tr ia m id e. A 360 mmol (4.3 g) amount
of graphite and 36.36 mmol (1.42 g) of K were heated for 10
Yield: 0.34 mmol (190 mg, 5%, based on 8a ). Anal. Calcd
for C24H30O5N3PFeSi (555.41): C, 51.90; H, 5.44. Found: C,
51.65; H, 5.72. IR (tetrahydrofuran): νCO 2008 (s), 1924 (vs),
25
min to 160 °C. The obtained golden yellow KC8 was cooled
1891 (vs, br); νCdC 1600 (w) cm-1 1H NMR (C6D6): δ 1.94 (d,
.
to -70 °C and suspended in 20 mL of tetrahydrofuran. Cr-
(CO)6 was added slowly, and the reaction mixture was warmed
to 25 °C overnight. The green slurry was cooled to -50 °C
and treated with 20 mmol (3.22 g) of (H2CdCH)SiCl3 (20a )
dissolved in 100 mL of tetrahydrofuran. The reaction mixture
was warmed to 0 °C, and 18.2 mmol (3.25 g) of [(CH3)2N]3Pd
O was added in one portion. After it was stirred for 1 h at 25
°C, the dark suspension was filtered through a pad of Celite
and the filtrate was concentrated to 30%. A 30 mL portion of
n-hexane was added. Complex 21 crystallized at -30 °C as
yellow needles.
3J PH ) 10.2 Hz, 18H, CH3); 7.10-8.10 (m, 12H, C2H2 and C6H5).
13C{1H} NMR (C6D6): δ 36.8 (br, CH3); 126.7, 127.5, 128.0,
128.4, 128.8, 131.4, 134.1, 138.2, 142.6, 145.5 (C2H2 and C6H5);
217.2 (CO). 29Si{1H} NMR (tetrahydrofuran/D2O): δ 83.6 (d,
2J PSi ) 29.7 Hz). 31P{1H} NMR (CDCl3): δ 22.13 (s). EI-MS
(m/z (relative intensity )): M+, 555 (19); M+ - CO, 527 (15);
M+ - 2 CO, 499 (16); M+ - 3 CO, 471 (44); M+ - 4 CO, 443
(100); M+ - Fe - 4 CO, 386 (14).
Ack n ow led gm en t. We are grateful to the Deutsche
Forschungsgemeinschaft (Sonderforschungsbereich SFB
247) and the Fonds der Chemischen Industrie for
financial support. Moreover, we thank Miss Anja Gehrig
for her assistance in laboratory, Mr. Thomas J annack
for carrying out the MS measurements, and Miss Sabine
Ahrens and Miss Karin Do¨rr for assistance in drawing
up the manuscript.
Yield: 10.4 mmol (4.8 g, 57%, based on 20a ). Mp: 119 °C
dec. Anal. Calcd for C13H21O6N3PClCrSi (461.82): C, 33.81;
H, 4.58. Found: C, 34.00; H, 4.81. IR (KBr): νCH 3053 (w),
3000 (m), 2945 (s), 2908 (m), 2858 (m), 2823 (w); νCO 2035 (vs),
1891 (vs, vbr); νCdC 1586 (vw); νPdO 1184 (s) cm-1
.
1H NMR
3
(CDCl3): δ 2.76 (d, J PH ) 10.4 Hz, 18 H, NCH3); 5.82 (dd,
3
2
2J HH ) 3.6 Hz, J HH ) 20.2 Hz, 1 H, C2H3); 5.91 (dd, J HH
)
3
3
3.6 Hz, J HH ) 13.9 Hz, 1 H, C2H3); 6.45 (dd, J HH ) 13.9 Hz,
3J HH ) 20.2 Hz, 1H, C2H3). 13C{1H} NMR (CDCl3): δ 36.8 (d,
2J PC ) 5.9 Hz, NCH3); 128.1 (C2H3); 144.8 (C2H3); 221.1 (CO);
225.9 (CO). 29Si{1H} NMR (tetrahydrofuran/D2O): δ 83.3 (d,
2J P-Si ) 35.4 Hz). 31P{1H} NMR (CDCl3): 22.58 (s). EI-MS
(m/e (relative intensity)): M+, 461 (22); M+ - CO, 433 (8); M+
- 2 CO, 405 (6); M+ - 3 CO, 377 (7); M+ - 4 CO, 349 (37); M+
- 5 CO, 321 (100).
Su p p or tin g In for m a tion Ava ila ble: Tables giving non-
hydrogen atomic coordinates and equivalent isotropic param-
eters, anisotropic displacement parameters, all bond distances
and angles, hydrogen coordinates and isotropic displacement
parameters, and torsion angles for 4, 11, 14, and 23 (32 pages).
Ordering information is given on any current masthead page.
OM980032J