(2-(dimethylamino)ethyl)cyclopentadienyl group VI metal carbonyl anions and divalent tin(IV) derivatives

Article abstract of DOI:10.1021/om0492101

Salts of (2-(dimethylamino)ethyl)cyclopentadienyl (Cp^N) group VI metal carbonyl anions ([M(CO)₃-(η⁵-Cp ^N)]^- (M = Cr, Mo, W)), important reagents for studies involving Cp^N, have been charact

Full text of DOI:10.1021/om0492101

1776
Organometallics 2005, 24, 1776-1779
(2-(Dimethylamino)ethyl)cyclopentadienyl Group VI
Metal Carbonyl Anions and Divalent Tin(IV) Derivatives
Paul J. Fischer,*,† Kristina M. Krohn,† Edward T. Mwenda,† and
Victor G. Young, Jr.‡
Department of Chemistry, Macalester College, Saint Paul, Minnesota 55105-1899, and
Department of Chemistry, X-ray Crystallographic Laboratory, University of Minnesota,
Minneapolis, Minnesota 55455-0431
Received October 12, 2004
Summary: Salts of (2-(dimethylamino)ethyl)cyclopen-
tadienyl (CpN) group VI metal carbonyl anions ([M(CO)3-
(η5-CpN)]- (M ) Cr, Mo, W)), important reagents for
studies involving CpN, have been characterized by X-ray
crystallography. These anions (M′ ) Mo, W) react with
R3SnCl (R ) Ph, cyclohexyl) to provide structurally
characterized tin(IV) derivatives.
[Mo(CO)3(η5-CpN)]- 3b have been synthesized, identified
by infrared spectra, and used in situ. However, to date,
no anions of the general formula [M(CO)x(CpN)]- have
been isolated or fully characterized. We have synthe-
sized and characterized [PPN][M(CO)3(η5-CpN)] (M )
Cr, Mo, W) in solution and the solid state.
Tetraorganotin compounds that are pentacoordinate
by virtue of intramolecular tin-amine dative bonding7
exhibit enhanced reactivity due to Sn-R bond elonga-
tion trans to the dative amine. Hypervalent tin com-
pounds are often exceptionally reactive toward redis-
tribution and Stille coupling reactions.8 Early examples
of pentacoordinate tetraorganotin compounds featured
bidentate C,N ligands where intramolecular Sn-N
binding is enforced by ligand rigidity.9 Subsequent
reports demonstrated that more flexible C,N chelating
ligands provide tetraorgano compounds with Sn-N
interactions.10,11 Although M-SnR3 bonds are ubiqui-
tous,12 the possibility of intramolecular amine coordina-
tion to SnR3 ligands has been poorly explored. We have
examined reactions of [M′(CO)3(η5-CpN)]- (M′ ) Mo, W)
with triorganotin halides to investigate the potential
utility of CpN to obtain intramolecular amine-stabilized
SnR3 complexes.
Introduction
The introduction of a donor-functionalized side chain
into a cyclopentadienyl transition-metal compound typi-
cally modulates complex reactivity relative to that of
the parent cyclopentadienyl species.1 The (2-(dimeth-
ylamino)ethyl)cyclopentadienyl ligand (CpN) has been
employed to enhance metal complex solubility in protic
solvents,2 stabilize electron-deficient metal centers,3
promote ligand exchange with low-valent metals,4 and
assist in catalysis.5 It has also been utilized in intra-
molecular Lewis acid-base adducts in which the teth-
ered dimethylamino group coordinates to an electron-
deficient ligand.4,6
Metal carbonyl anions containing CpN are reagents
for these studies. The anions [NiCO(η5-CpN)]- 6a and
* To whom correspondence should be addressed. E-mail: fischer@
macalester.edu.
Results and Discussion
† Macalester College.
‡ University of Minnesota.
Reactions of M(CO)6 and NaCpN followed by metath-
esis with PPNCl afforded [PPN][M(CO)3(η5-CpN)]
(Scheme 1). The ν(CO) infrared spectra of Na[M(CO)3-
(η5-CpN)] in ethereal solvents (Table S1) indicate Cs ion
pairs analogous to Na[M(CO)3(η5-Cp)].13 The two ν(CO)
IR absorptions of 1-3 indicate C3v M(CO)3 units un-
(1) (a) Jutzi, P.; Siemeling, U. J. Organomet. Chem. 1995, 500, 175.
(b) Jutzi, P.; Redeker, T. Eur. J. Inorg. Chem. 1998, 663. (c) Mu¨ller,
C.; Vos, D.; Jutzi, P. J. Organomet. Chem. 2000, 600, 127. (d) Jutzi,
P.; Dahlhaus, J. Coord. Chem. Rev. 1994, 137, 179.
(2) (a) Kaul, B. B.; Noll, B.; Renshaw, S.; Rakowski DuBois, M.
Organometallics 1997, 16, 1604. (b) Philippopoulos, A. I.; Bau, R.;
Poilblanc, R.; Hadjiliadis, N. Inorg. Chem. 1998, 37, 4822. (c) Philip-
popoulos, A. I.; Hadjiliadis, N.; Hart, C. E.; Donnadieu, B.; McGowan,
P. C.; Poilblanc, R. Inorg. Chem. 1997, 36, 1842.
(3) (a) Guohua, L.; Beetstra, D. J.; Meetsma, A.; Hessen, B. Orga-
nometallics 2004, 23, 3914. (b) Wang, T.-F.; Lee, T.-Y.; Chou, J.-W.;
Ong, C.-W. J. Organomet. Chem. 1992, 423, 31. (c) Jutzi, P.; Kleimeier,
J. J. Organomet. Chem. 1995, 486, 287. (d) Baretta, A.; Chong, K. S.;
Cloke, F. G. N.; Feigenbaum, A.; Green, M. L. H. J. Chem. Soc., Dalton
Trans. 1983, 861. (e) Wang, T.-F.; Wen, Y.-S. J. Organomet. Chem.
1992, 439, 155. (f) Wang, T.-F.; Lai, C.-Y.; Hwu, C.-C.; Wen, Y.-S.
Organometallics 1997, 16, 1218. (g) Wang, T.-F.; Juang, J. P.; Lin, K.
J. Bull. Inst. Chem., Acad. Sin. 1995, 42, 41. (h) Wang, T.-F.; Lai, C.-
Y.; Wen, Y.-S. J. Organomet. Chem. 1996, 523, 187.
(7) (a) Baukov, Y. I.; Tandura, S. N. In The Chemistry of Organic
Germanium, Tin and Lead Compounds; Rappoport, Z., Ed.; Wiley:
Chichester, U.K., 2002; Vol. 2, Chapter 16, pp 1072-1078. (b) Mackay,
K. M. In The Chemistry of Organic Germanium, Tin and Lead
Compounds; Patai, S., Ed.; Wiley: New York, 1995; Chapter 2, p 115-
119.
(8) (a) Jastrzebski, J. T. B. H.; Knaap, C. T.; van Koten, G. J.
Organomet. Chem. 1983, 255, 287. (b) Vedejs, E.; Haight, A. R.; Moss,
W. O. J. Am. Chem. Soc. 1992, 114, 6556. (c) Jousseaume, B.;
Villeneuve, P. J. Chem. Soc., Chem. Commun. 1987, 513. (d) Brown,
J. M.; Pearson, M.; Jastrzebski, J. T. B. H.; van Koten, G. J. Chem.
Soc., Chem. Commun. 1992, 1440.
(4) Nlate, S.; Herdtweck, E.; Fischer, R. A. Angew. Chem., Int. Ed.
Engl. 1996, 35, 1861.
(5) (a) Zhang, H.; Ma, J.; Qian, Y.; Huang, J. Organometallics 2004,
23, 5681. (b) Bradley, S.; Camm, K. D.; Furtado, S. J.; Gott, A. L.;
McGowan, P. C.; Podesta, T. J.; Thornton-Pett, M. Organometallics
2002, 21, 3443. (c) Jolly, P.; Ionas, K.; Verkovnic, G. P. I. German
Patent 19630580 A1, 1998. (d) Flores, J. C.; Chien, J. C. W.; Rausch,
M. D. Organometallics 1994, 13, 4140.
(6) (a) Fischer, R. A.; Nlate, S.; Hoffmann, H.; Herdtweck, E.;
Blu¨mel, J. Organometallics 1996, 15, 5746. (b) Weiss, J.; Herdtweck,
E.; Nlate, S.; Mattner, M.; Fischer, R. A. Chem. Ber. 1996, 129, 297.
(9) (a) Jastrzebski, J. T. B. H.; Boersma, J.; Esch, P. M.; van Koten,
G. Organometallics 1991, 10, 930.
(10) (a) Kumar Das, V. G.; Mun, L. K.; Wei, C.; Mak, T. C. W.
Organometallics 1987, 6, 10. (b) Kumar Das, V. G.; Mun, L. K.; Wei,
C.; Blunden, S. J.; Mak, T. C. W. J. Organomet. Chem. 1987, 322, 163.
(11) Rippstein, R.; Kickelbick, G.; Schubert, U. Inorg. Chim. Acta
1999, 290, 100.
(12) Holt, M. S.; Wilson, W. L.; Nelson, J. H. Chem. Rev. 1989, 89,
11.
10.1021/om0492101 CCC: $30.25 © 2005 American Chemical Society
Publication on Web 03/01/2005

Notes
Organometallics, Vol. 24, No. 7, 2005 1777
Scheme 1
Figure 2. Molecular structure of the anion of 3 (50%
thermal ellipsoids). Selected bond lengths (Å) and angles
(deg): W-C(1) ) 2.390(4), W-C(2) ) 2.374(4), W-C(3) )
2.363(4), W-C(4) ) 2.374(4), W-C(5) ) 2.389(4), W-C(10)
) 1.928(4), W-C(11) ) 1.931(4), W-C(12) ) 1.919(4),
C(10)-O(1) ) 1.174(5), C(11)-O(2) ) 1.174(5), C(12)-O(3)
) 1.191(4); C(10)-W-C(12) ) 86.02(17), C(10)-W-C(11)
) 89.43(18), C(12)-W-C(11) ) 88.64(17), O(1)-C(10)-W
) 177.5(5), O(2)-C(11)-W ) 177.1(4), O(3)-C(12)-W )
178.7(4).
perturbed by PPN+ and the amine in solution. The
13CO chemical shifts of 1-3 are nearly identical with
those of [M(CO)3(η5-Cp)]- (Table S2).14
Structural Characterization of [PPN][M(CO)3-
(η5-CpN)]. Salts 1-3 contain the first crystallographi-
cally characterized triad of [M(CO)3(C5H4R)]- com-
plexes. The three-legged piano-stool structures of 1 and
3 are shown in Figures 1 and 2, respectively; 2 is
Cr-C-O, 178.4(3)°) are statistically identical with those
of [CpCr(NC-tBu)4][Cr(CO)3(η5-Cp)].16 The distance be-
tween an η5-Cp and a Cr(CO)3 fragment appears inde-
pendent of cyclopentadienyl substitution, as the average
Cr-C(dienyl) distance in 1 is statistically indistinguish-
able from that of [PPN][Cr(CO)3(η5-C5Ph5)],17 [PPh4][Cr-
(CO)3(η5-C5H4CHO)],18 and Cr(CO)3(η5-C5H4C(CH3)2-
PEt3).19 Important average structural parameters for 2
(Mo-C(O), 1.926(2) Å; C-O, 1.172(2) Å; Mo-C(dienyl),
2.381(7) Å; (O)C-Mo-C(O), 86.2(8)°; Mo-C-O, 179.0-
(6)°) are statistically indistinguishable from those of
[PPN][Mo(CO)3(η5-Cp)].20 Both 1 and 2 feature slight
M-C(1) elongation due to influence of the pendant
amine. The Cr-C(1) distance in 1 is significantly longer
(∼4σ) than the average Cr-C(2-5) distance (2.216(5)
Å), while the Mo-C(1) distance of 2 (2.394(3) Å) is
approximately 5σ longer than the average Mo-C(2,5)
length (2.378(3) Å). The small absolute differences
between these distances (∼0.02 Å) do not rule out
consideration of 1 and 2 as η5-CpN complexes. Important
average lengths and angles of 3 (W-C(O), 1.926(6) Å;
C-O, 1.18(1) Å; W-C(dienyl), 2.38(1) Å; (O)C-W-C(O),
88(2)°; W-C-O, 177.8(8)°) are statistically identical
with the corresponding parameters of 2. Although 3 is
an η5-CpN complex, its M-C(dienyl) distances are ir-
regular relative to those in 2. The W-C(1) and W-C(5)
distances are nearly 7σ longer than W-C(3), although
the absolute difference is small (∼0.03 Å). This minor
distortion may be related to an alternate position of the
pendant group, as rotation about the C(6)-C(7) bond
is much more pronounced in 3 relative to 2 and 1. The
C1-C6-C7-N1 torsion angle in 3 is -156.5(3)°, while
this angle in 2 is -70.0(4)°. Disordered solvent of
crystallization (most likely 2 THF molecules per unit
cell; see the Supporting Information) may influence the
orientation of the amine in 3.
Figure 1. Molecular structure of the anion of 1 (50%
thermal ellipsoids). Selected bond lengths (Å) and angles
(deg): Cr-C(1) ) 2.235(3), Cr-C(2) ) 2.214(3), Cr-C(3)
) 2.211(3), Cr-C(4) ) 2.218(3), Cr-C(5) ) 2.222(3), Cr-
C(10) ) 1.810(3), Cr-C(11) ) 1.815(3), Cr-C(12) )
1.815(3), C(10)-O(1) ) 1.175(3), C(11)-O(2) ) 1.174(3),
C(12)-O(3) ) 1.183(3); C(10)-Cr-C(12) ) 87.90(12), C(10)-
Cr-C(11) ) 88.07(12), C(12)-Cr-C(11) ) 89.25(12), O(1)-
C(10)-Cr ) 178.6(2), O(2)-C(11)-Cr ) 178.6(3), O(3)-
C(12)-Cr ) 178.0(2).
displayed in Figure S1 (Supporting Information).15 The
amines of 1-3 are not engaged in any interactions with
PPN+ or M(CO)3 units. In 1 and 2, the η5-CpN ring is
oriented such that methylene carbon C(6) is roughly
opposite the CO defined by C(12). This permits the
2-(dimethylamino)ethyl substituent to occupy space
between the other two CO ligands. The η5-CpN ring is
oriented differently in 3; C(6) is almost directly above
the CO defined by C(10). Important average structural
parameters for 1 (Cr-C(O), 1.813(3) Å; C-O, 1.177(5)
Å; Cr-C(dienyl), 2.220(9) Å; (O)C-Cr-C(O), 88.4(7)°;
(16) Shen, J. K.; Freeman, J. W.; Hallinan, N. C.; Rheingold, A. L.;
Arif, A. M.; Ernst, R. D.; Basolo, F. Organometallics 1992, 11, 3215.
(17) Hoobler, R. J.; Hutton, M. A.; Dillard, M. M.; Castellani, M. P.;
Rheingold, A. L.; Rieger, A. L.; Reiger, P. H.; Richards, T. C.; Geiger,
W. E. Organometallics 1993, 12, 116.
(18) Edelmann, F.; Behrens, U. Chem. Ber. 1984, 117, 3463.
(19) Koch, O.; Edelmann, F.; Behrens, U. Chem. Ber. 1982, 115,
1313.
(20) Evans, C.; Nicholson, B. K.; Oliver, A. G. Acta Crystallogr. 2001,
E57, m504.
(13) Darensbourg, M. Y.; Jimenez, P.; Sackett, J. R.; Hanckel, J.
M.; Kump, R. L. J. Am. Chem. Soc. 1982, 104, 1521.
(14) Behrens, U.; Edelmann, F. J. Organomet. Chem. 1984, 263, 179.
(15) Analogous labeling schemes are used in the molecular struc-
tures of 1-3 and 4 and 5, respectively.

1778 Organometallics, Vol. 24, No. 7, 2005
Notes
the amine is not conducive to an intramolecular N-Sn
interaction.
The nearly identical M′-Sn lengths of 4 and 5
(2.8215(4) Å) are similar to those of [PPN][W(SnPh3)-
(CO)5]25 and {p-[(CO)3MoC5H4C(O)]2C6H4}{(Ph2Sn)2S}.26
The metallostannylenes M′(SnC6H3-2,6-Mes2)(CO)3(η5-
Cp) (M′ ) Mo (8), W (9)) exhibit slightly elongated
M-Sn distances.23 The average M-C(dienyl) lengths of
4 and 5 are uniform (2.34(2) Å) and statistically
indistinguishable from those of 8 (2.348(5) Å) and 9
(2.346(9) Å), but the M-C(dienyl) lengths of 4 and 5
are more irregular. Specifically, the average M-C(4,7,8)
distances (4, 2.352(8) Å; 5, 2.352(12) Å) are statistically
longer than the average M-C(5,6) lengths (4, 2.314(3)
Å; 5, 2.314(8) Å). The η5-CpN groups of 4 and 5 engage
in minor tilting due to the influence of SnPh3 and the
pendant group. Greater M-C(dienyl) uniformity in 8
and 9 is consistent with longer metal-tin bond lengths.
The SnPh3 ligands of 4 and 5 are modestly distorted
from tetrahedral geometries. The ipso-C-Sn-ipso-C
angles range from 105.60(9) to 108.06(8)° in 4 and
105.82(14) to 107.98(14)° in 5. The slight compression
in these angles accommodates C(19)-Sn-M′ angles of
116.15(6) and 115.87(10)° in 4 and 5, respectively. It is
reasonable to attribute this larger angle to steric
hindrance between the phenyl ring defined by C(19) and
the CO defined by C(3). However, rationalization of
SnPh3 ligand geometries based solely on intramolecular
considerations is tenuous. The SnPh3 of [W(SnPh3)CO)5]-
is considerably distorted, with ipso-C-Sn-ipso-C angles
of 98.6(2), 98.8(2), and 104.2(2)°.25 The flat phenyl rings
appear to render the SnPh3 ligand geometry rather
susceptible to crystal-packing forces.
Figure 3. Molecular structure of 4 (50% thermal el-
lipsoids). Selected bond lengths (Å) and angles (deg): Mo-
Sn ) 2.8152(3), Mo-C(1) ) 1.989(3), Mo-C(2) ) 1.985(3),
Mo-C(3) ) 1.972(3), Mo-C(4) ) 2.357(2), Mo-C(5) )
2.316(2), Mo-C(6) ) 2.312(2), Mo-C(7) ) 2.342(2), Mo-
C(8) ) 2.356(2); C(1)-Mo-Sn ) 130.31(9), C(3)-Mo-C(2)
) 107.40(11), C(3)-Mo-Sn ) 70.97(8), C(2)-Mo-Sn )
72.74(8), C(3)-Mo-C(1) ) 79.68(12), C(2)-Mo-C(1) )
79.29(11).
Tin(IV) Derivatives. Reactions of in situ Na[M′-
(CO)3(η5-CpN)] (M′ ) Mo, W) and R3SnCl afforded M′-
(SnR3)(CO)3(η5-CpN) (Scheme 1). The solubility of these
substances in hydrocarbons is significantly higher than
that of their Cp analogues.21 Isolation of M′(SnMe3)-
(CO)3(η5-CpN) was unsuccessful, since the melting points
of these exceedingly pentane soluble derivatives are
<-20 °C. The ν(CO) IR spectra of 4-7 are diagnostic
of four-legged piano-stool CpM(CO)3L structures. These
spectra for 4 and 5 are nearly identical with those of
M′(SnPh3)(CO)3(η5-Cp).22
The flexibility of the CpN amine is too great to permit
N-Sn dative bonding to these SnR3 ligands. Less
sterically hindered, more Lewis acidic ligands are
required to entice adduct formation. An examination of
reactions of [M(CO)3(η5-Cp)]- and related anions with
R2SnX2, RSnX3, SnX4, and other electrophiles is under-
way.
The spectral data of 6 and 7 provide additional points
of reference to gauge stannylene donor ability. The
ligands SnAr (Ar ) C6H3-2,6-R2 (R ) C6H2-2,4,6-Me3,
C6H2-2,4,6-Pri3)) of M′(SnAr)(CO)3(η5-Cp) were deemed
1
better donors than SnMe3 on the basis of IR and H
NMR spectral comparisons to M′(SnMe3)(CO)3(η5-Cp).23
Infrared data of 6 and 7 suggest that SnAr ligands are
stronger donors than SnCy3 (Table S3). This difference
is not well-defined on the basis of 13C NMR; the carbonyl
carbons of 6 and 7 are deshielded similarly to those of
the Mo and W stannylenes. A dramatic upfield shift of
the metallostannylene Cp hydrogen resonances is at-
tributed to strong SnAr donation.23 These absorptions
are more than 1 ppm upfield from those of 6 and 7.
Structural Characterization of M′(SnPh3)(CO)3-
(η5-CpN). The isostructural compounds 4 and 5 were
characterized by X-ray crystallography. The molecular
structures of 4 and 5 are displayed in Figures 3 and S2
(Supporting Information), respectively. The geometric
parameters of 4 and 5 satisfy the requirements for CpM-
(CO)3L four-legged piano-stool structures.24 In 4 and 5,
the amine is oriented away from nearly tetrahedral and
unperturbed SnPh3 ligands. The lack of constraints on
Experimental Section
General Procedures. All operations were performed under
an atmosphere of 99.5% argon purified by passage through a
column of activated Aceto Corp. catalyst R3-11 and 10 Å
molecular sieves. Standard Schlenk techniques were employed
with double-manifold vacuum lines.27 Solids were handled in
a glovebox. Solvents were purified by standard procedures.
Literature procedures were employed to prepare NaCpN.28
M(CO)6 (M ) Cr, Mo, W) and R3SnCl (R ) Ph, Cy) were used
as received (Aldrich). PPNCl (Aldrich) was recrystallized from
H2O and dried. Solution IR spectra were acquired on a Nicolet
Magna 550 FTIR spectrometer with samples sealed in 0.1 mm
gastight NaCl cells. NMR samples were sealed under argon
into 5 mm tubes and analyzed on a Varian Gemini 300 MHz
FT-NMR spectrometer at ambient temperature. 1H and 13C
(25) Darensbourg, M. Y.; Liaw, W.-F.; Reibenspies, J. Inorg. Chem.
1988, 27, 2555.
(26) Tang, L.-F.; Chai, J.-F.; Zhao, S.-B.; Wang, J.-T. J. Organomet.
Chem. 2003, 669, 57.
(27) (a) Shriver, D. F.; Drezdon, M. A. The Manipulation of Air-
Sensitive Compounds, 2nd ed.; Wiley-Interscience: New York, 1986.
(b) Ellis, J. E. ACS Symp. Ser. 1987, No. 357, 34.
(28) (a) Bradley, S.; Corradi, M. M.; Camm, K. D.; Furtado, S. J.;
McGowan, P. C.; Mumtaz, R.; Thornton-Pett, M. J. Organomet. Chem.
2002, 656, 49. (b) Rees, W. S, Jr..; Dippel, K. A. Org. Prep. Proceed.
Int. 1992, 24, 527.
(21) Patil, H. R. H.; Graham, W. A. G. Inorg. Chem. 1966, 5, 1401.
(22) IR spectra of M′(SnPh3)(CO)3(η5-Cp) synthesized as described
in ref 21: M′ ) Mo, ν(CO) 2000 (s), 1928 (m, sh), 1902 (s) cm-1; M′ )
W, ν(CO) 1995 (s), 1919 (m, sh), 1897 (s) cm-1
.
(23) Eichler, B. E.; Phillips, A. D.; Haubrich, S. T.; Mork, B. V.;
Power, P. P. Organometallics 2002, 21, 5622.
(24) Kuba´cek, P.; Hoffmann, R.; Havias, Z. Organometallics 1982,
1, 180.

Notes
Organometallics, Vol. 24, No. 7, 2005 1779
chemical shifts are reported in parts per million (δ) and are
given with reference to residual 1H and 13C solvent references
relative to TMS. Melting points (uncorrected) were determined
under argon in sealed capillary tubes on a Laboratory Devices
Mel-Temp apparatus. Microanalyses were carried out by H.
Malissa and G. Reuter Analytische Laboratorien, Lindlar,
Germany.
Similar procedures were conducted to synthesize 1-3 and
4-7, respectively. Representative procedures for 1 and 4 are
provided below. Complete experimental details for 2, 3, and
5-7 are given in the Supporting Information.
(CD2Cl2, 300 MHz): δ 7.68-7.44 (m, 6H, ortho, SnPh3), 7.42-
7.26 (m, 9H, meta/para, SnPh3), 5.42 (app t, J ) 2.1 Hz, 2H,
Cp), 5.18 (app t, J ) 2.1 Hz, 2H, Cp), 2.31 (m, 4H, CH2CH2),
2.14 (s, 6H, CH3). 13C{1H} NMR (CD2Cl2, 75.5 MHz): δ 230.5
2
(s, CO (117,119Sn-13C satellites (merged) 230.72, 230.35, JSnC
) 27.9 Hz)), 225.6 (s, CO (117,119Sn-13C satellites 226.60,
2
226.56, 224.72, 224.68, JSnC ) 142 Hz)).
W(SnPh3)(CO)3(η5-CpN) (5). Anal. Calcd for C30H29NO3-
SnW: C, 47.78; H, 3.88; N, 1.86. Found: C, 47.74, H, 3.99; N,
1.92. Mp: 106-107 °C dec. IR (DME): ν(CO) 1992 (s), 1917
(m, sh), 1895 (s) cm-1. IR (THF): ν(CO) 1992 (s), 1916 (m, sh),
1894 (s) cm-1. IR (pentane): ν(CO) 2000 (s), 1927 (m), 1906
[PPN][Cr(CO)3(η5-CpN)] (1). CH3CN (80 mL) was added
to Cr(CO)6 (0.345 g, 1.57 mmol) and NaCpN (0.300 g, 1.88
mmol). The yellow solution was refluxed for 64 h. The CH3-
CN was removed in vacuo, and THF (80 mL) was added. The
suspension was filtered into PPNCl (0.991 g, 1.73 mmol) and
stirred for 3 h prior to filtration through alumina. The THF
was removed in vacuo until ∼5 mL remained. A yellow solid
precipitated upon addition of Et2O (80 mL). The solid was
isolated via filtration, washed with Et2O (4 × 15 mL), and
dried in vacuo. Recrystallization (THF/Et2O) provided yellow,
moderately air-sensitive microcrystals (0.567 g, 45%). Anal.
Calcd for C48H44CrN2O3P2: C, 71.10; H, 5.47; N, 3.45. Found:
C, 70.91, H, 5.51; N, 3.55. Mp: 132 °C dec. IR (THF): ν(CO)
1890 (m), 1776 (s) cm-1. IR (CH3CN): ν(CO) 1889 (s), 1771 (s)
(s) cm-1. IR (Nujol): ν(CO) 1980 (s), 1913 (s, sh), 1885 (s) cm-1
.
1H NMR (CD2Cl2, 300 MHz): δ 7.56-7.34 (m, 6H, ortho,
SnPh3), 7.32-7.16 (m, 9H, meta/para, SnPh3), 5.38 (app t, J
) 2.1 Hz, 2H, Cp), 5.15 (app t, J ) 2.1 Hz, 2H, Cp), 2.30-2.16
(m, 4H, CH2CH2), 2.02 (s, 6H, CH3). 13C{1H} NMR (CD2Cl2,
75 MHz): δ 218.8 (s, CO, (117,119Sn-13C satellites (merged)
2
218.98, 218.63, JSnC ) 26.4 Hz)), 215.1 (s, CO, (117,119Sn-13C
2
satellites 216.12, 216.01, 214.42, 214.11, JSnC ) 136 Hz)).
Mo(SnCy3)(CO)3(η5-CpN) (6). Anal. Calcd for C30H47O3-
NSnMo: C, 52.65; H, 6.92; N, 2.05. Found: C, 52.78, H, 6.93;
N, 2.09. Mp: 109-110 °C dec. IR (THF): ν(CO) 1982 (s), 1907
(m, sh), 1886 (s) cm-1. IR (Nujol): ν(CO) 1970 (s), 1892 (s, br)
cm-1. 1H NMR (CD2Cl2, 300 MHz): δ 5.41 (app t, J ) 2.1 Hz,
2H, Cp), 5.32 (app t, J ) 2.1 Hz, 2H, Cp), 2.53-2.35 (m, 4H,
CH2CH2), 2.21 (s, 6H, CH3), 2.02-1.19 (m, 33H, SnCy3). 13C-
{1H} NMR (CD2Cl2, 75.5 MHz): δ 232.4 (s, br, CO), 226.3 (s,
br, CO).
1
cm-1. IR (Nujol): ν(CO) 1886 (m), 1755 (s, br) cm-1. H NMR
(CD3CN, 300 MHz): δ 7.62-7.34 (m, 30H, PPN), 4.24 (app t,
J ) 2.1 Hz, 2H, Cp), 4.17 (app t, J ) 2.1 Hz, 2H, Cp), 2.22 (m,
4H, CH2CH2), 2.03 (s, 6H, CH3). 13C{1H} NMR (CD3CN, 75
MHz): δ 247.0 (s, CO).
W(SnCy3)(CO)3(η5-CpN) (7). Anal. Calcd for C30H47O3-
NSnW: C, 46.66; H, 6.13; N, 1.81. Found: C, 46.49, H, 6.01;
N, 1.88. Mp: 113-114 °C dec. IR (DME): ν(CO) 1979 (s), 1900
(m, sh), 1880 (s) cm-1. IR (pentane): ν(CO) 1987 (s), 1911 (m),
1891 (s) cm-1. IR (Nujol): ν(CO) 1983 (m, sh), 1966 (s), 1903
(s), 1886 (s, sh) cm-1. 1H NMR (CD2Cl2, 300 MHz): δ 5.49 (app
t, J ) 2.1, 2H, Cp), 5.42 (app t, J ) 2.1 Hz, 2H, Cp), 2.56 (t, J
) 7.20 Hz, 2H, CH2N), 2.39 (t, J ) 7.20 Hz, 2H, CH2CH2N),
2.21 (s, 6H, CH3), 2.03-1.16 (m, 33H, SnCy3). 13C{1H} NMR
(CD2Cl2, 75 MHz): δ 220.7 (s, CO), 216.2 (s, CO).
X-ray Crystallography. X-ray-quality crystals of 1-3 were
obtained by diffusion of Et2O into a THF solution of each salt.
Crystals of 4 were obtained from a supersaturated THF
solution. Crystals of 5 were obtained by evaporation of a THF
solution. All manipulations with the crystals of 1-4 were
conducted in a N2-filled glovebag. Crystals of 1 and 2 were
selected from the mother liquor; those of 3 and 4 had been
dried in vacuo. A crystal of 5 was selected in air.
[PPN][Mo(CO)3(η5-CpN)] (2). Anal. Calcd for C48H44-
MoN2O3P2: C, 67.45; H, 5.19; N, 3.28. Found: C, 67.28, H,
5.25; N, 3.37. Mp: 138 °C dec. IR (THF): ν(CO) 1894 (s), 1779
(s) cm-1. IR (CH3CN): ν(CO) 1893 (s), 1775 (s) cm-1. IR
1
(Nujol): ν(CO) 1894 (s), 1771 (s, br) cm-1. H NMR (CD3CN,
300 MHz): δ 7.60-7.34 (m, 30H, PPN), 4.91 (app t, J ) 2.1
Hz, 2H, Cp), 4.81 (app t, J ) 2.1 Hz, 2H, Cp), 2.26 (m, 4H,
CH2CH2), 2.04 (s, 6H, CH3). 13C{1H} NMR (CD3CN, 75 MHz):
δ 237.3 (s, CO).
[PPN][W(CO)3(η5-CpN)] (3). Anal. Calcd for C48H44WN2-
O3P2: C, 61.15; H, 4.70; N, 2.97. Found: C, 59.18, H, 4.83; N,
2.98. Mp: 133 °C dec. IR (DME): ν(CO) 1888 (s), 1774 (s) cm-1
.
IR (THF): ν(CO) 1888 (s), 1774 (s) cm-1. IR (Nujol): ν(CO)
1887 (s), 1767 (s) cm-1. 1H NMR (CD3CN, 300 MHz): δ 7.70-
7.42 (m, 30H, PPN), 5.03 (app t, J ) 2.1 Hz, 2H, Cp), 4.93
(app t, J ) 2.1 Hz, 2H, Cp), 2.43-2.24 (m, 4H, CH2CH2), 2.14
(s, 6H, CH3). 13C{1H} NMR (CD3CN, 75 MHz): δ 228.1 (s, CO,
1
(
183W-13C satellites 229.42, 226.80, JWC ) 198 Hz)).
Mo(SnPh3)(CO)3(η5-CpN) (4). THF (80 mL) was added to
Acknowledgment. The donors of Petroleum Re-
search Fund, administered by the American Chemical
Society (ACS PRF 39928-GB3), and an award from
Research Corp. (CC5932) supported this research. We
are grateful for the generosity of these agencies and
Macalester College. We are indebted to William W.
Brennessel (Crystallographic Laboratory). P.J.F. thanks
Prof. John E. Ellis for his support and encouragement
over the years.
Mo(CO)6 (0.829 g, 3.14 mmol) and NaCpN (0.600 g, 3.77 mmol).
The yellow solution was refluxed for 15 h. Addition of Ph3-
SnCl (1.21 g, 3.14 mmol) in THF (30 mL) resulted in a pale
yellow suspension. The [Mo(CO)3(η5-CpN)]- was consumed
within 30 min. The suspension was filtered through alumina.
THF was removed in vacuo, revealing a yellow, oily residue.
The product was extracted with pentane (5 × 70 mL); each
colorless extract was filtered. Pentane was removed in vacuo
from the combined extracts until a yellow solid had precipi-
tated. The suspension (∼75 mL) was cooled and filtered at -50
°C. The pale yellow, moderately air-sensitive microcrystals
(1.423 g, 68%) were washed with pentane (-50 °C, 5 × 15 mL)
and dried in vacuo. Anal. Calcd for C30H29O3NSnMo: C, 54.09;
H, 4.39; N, 2.10. Found: C, 54.12, H, 4.49; N, 2.23. Mp: 101-
102 °C dec. IR (THF): ν(CO) 1997 (s), 1925 (m, sh), 1902 (s)
Supporting Information Available: Text giving ad-
ditional experimental details, 13C NMR spectral data for 1-7,
and tables giving spectroscopic data and crystallographic data
as well as data collection, solution, and refinement information
for 1-5; crystallographic data are also given as CIF files. This
material is available free of charge via the Internet at
http://pubs.acs.org.
cm-1. IR (CH2Cl2): ν(CO) 2000 (s), 1928 (m, sh), 1899 (s) cm-1
.
IR (pentane): ν(CO) 2003 (s), 1935 (m), 1912 (s) cm-1. IR
(Nujol): ν(CO) 1990 (m), 1922 (m, sh), 1893 (s) cm-1. 1H NMR
OM0492101