Structure and bonding properties of the complex (η5-diphenylfulvene)Mn(CO)3+

Article abstract of DOI:10.1021/om000587q

Reaction of cymantrene (6) with n-butyl-lithium followed by benzophenone and subsequent hydrolysis yielded 1-(diphenylhydroxymethyl)(η⁵-cyclopentadienyl)(tricarbonyl)manganese (7). Treatment of 7 with HBArF·2Et₂O in methylene chloride affords the blue cation 2b. Investigations of single crystals of 2b by means of the X-ray technique showed a displacement of the exo carbon by 6.6° toward the metal and a pronounced bond alternation of the C-C bonds of the fulvene moiety. DFT calculations on the parent system 2a and on a system with a planar fulvene moiety (2a′) yielded an energy difference of 23 kJ/mol in favor of 2a. As a result of the bending of the exo methylene group the positive charge at the metal is increased and at C9 decreased.

Full text of DOI:10.1021/om000587q

Organometallics 2001, 20, 227-230
227
Str u ctu r e a n d Bon d in g P r op er ties of th e Com p lex
+
(η5-Dip h en ylfu lven e)Mn (CO)3
Martin A. O. Volland, Steffen Kudis, Gu¨nter Helmchen,* Isabella Hyla-Kryspin,
Frank Rominger, and Rolf Gleiter*
Organisch-Chemisches Institut der Universita¨t Heidelberg, Im Neuenheimer Feld 270,
D 69120 Heidelberg, Germany
Received J uly 10, 2000
Summary: Reaction of cymantrene (6) with n-butyl-
lithium followed by benzophenone and subsequent hy-
drolysis yielded 1-(diphenylhydroxymethyl)(η5-cyclopen-
tadienyl)(tricarbonyl)manganese (7). Treatment of 7 with
HBArF‚2Et2O in methylene chloride affords the blue
cation 2b. Investigations of single crystals of 2b by
means of the X-ray technique showed a displacement of
the exo carbon by 6.6° toward the metal and a pro-
nounced bond alternation of the C-C bonds of the
fulvene moiety. DFT calculations on the parent system
2a and on a system with a planar fulvene moiety (2a ′)
yielded an energy difference of 23 kJ / mol in favor of 2a .
As a result of the bending of the exo methylene group
the positive charge at the metal is increased and at C9
decreased.
In tr od u ction
In the series of fulvene complexes1 with transition
metals of groups VI-VIII, the structures of 1b,2 3b,3
and 4b4 have been investigated by means of the X-ray
technique. Common to all of them is a bending of the
diphenylmethylidene group toward the metal expressed
by the parameters R and d as shown in 5. It is most
pronounced in the case of 1b (R ) 31°)2 and less in 4b
(R ) 11° or 6°).4 In this series data on 2 are missing.
Therefore we have synthesized 2b and investigated the
structure by applying the X-ray technique. In addition
to these experimental investigations we have carried out
model calculations on 2a by using the density functional
theory (DFT).5
equimolar amount of the bis(ether) complex of tetrakis-
[3,5-bis(trifluoromethyl)phenyl]boric acid (HBArF‚2Et2O)6
furnished a deep blue solution from which 2b can be
isolated in 60% yield as the BArF- salt. Single crystals
obtained from a CH2Cl2/pentane solution of 2bBAr F at
-6 °C allowed a high quality X-ray crystal structure
analysis to be carried out. The molecular structures of
2b and 7 are displayed in Figure 1. The most relevant
distances of both structures are listed in Table 1. As
anticipated from the isolobal species 1b we find in 2b a
Resu lts a n d Discu ssion
The preparation of 2b commenced with cymantrene
6 which was metalated at -78 °C with n-BuLi. The
lithio derivative was treated with benzophenone to give
the alcohol 7 in 87% yield (Scheme 1). Treatment of a
solution of the alcohol in dichloromethane with an
Sch em e 1
(1) For reviews, see: Kerber, R. C.; Ehntholt, D. J . Synthesis 1970,
449. Watts, W. E. Organomet. Chem. Rev. 1979, 7, 399. Cais, M.
Organomet. Chem. Rev. 1966, 1, 435.
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Molecules; Oxford University Press: Oxford, 1989. Koch, W.; Holth-
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VCH: Weinheim, 2000.
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11, 3920.
10.1021/om000587q CCC: $20.00 © 2001 American Chemical Society
Publication on Web 12/06/2000

228 Organometallics, Vol. 20, No. 1, 2001
Notes
Ta ble 2. Selected Geom etr ica l P a r a m eter s for
1b-4b
compd
R (deg)
â (deg)
d (Å)
ref
1b
2b
31.0
6.6
20.7
10.8
6.4
2.53
3.05
2.72
2.95
3.03
2
this work
3b
8.1
12.4
13.4
3
4
4
4ba
4b′a
a
There are two independent molecules in the unit cell.
In Table 2 we have compared the parameters R, â,
and d (as defined in 5) for 1b-4b. In all four cases there
is an interaction between the exo carbon and the metal.
It is smallest in 2b and 4b and largest in 1b. The
interaction prevailing in 2b can also be seen from the
comparison between the 13C NMR spectra of 2b with 7.
The difference in the 13C chemical shift of the exo-
methylidene carbon was found to be ∆δ (7-2b) 91.4
ppm. The corresponding values for 3b4 and 4b4 are 71
and 65 ppm, respectively.
To understand the electronic effects we optimized the
geometry of 2a fully within Cs symmetry constraints.
All calculations were carried out with the hybrid Har-
tree-Fock/density functional theory method, known by
its acronym B3LYP.7 A single all-electron basis set was
used throughout the present studies. The Mn atom was
described by Wachters (14s, 9p, 5d) basis set8 aug-
mented with a 4f polarization function (Rf ) 0.96). The
contraction scheme of [9s, 5p, 3d, 1f] corresponds to a
double- and triple-ê basis for the core and valence
electrons, respectively. Standard 6-311G* basis sets
were used for C, O, and H.9 The presented structures
were optimized with analytical gradient procedures and
correspond to fully converged geometries with gradients
and displacements below the standard thresholds. To
test the stationarity of the optimized structures, vibra-
tional frequencies were obtained from analytical calcu-
lations of the Hessian matrixes. The electronic structure
of the investigated compounds was characterized with
help of the natural population analysis (NPA) and
natural bond orbital (NBO) methods.10 The calculations
have been carried out with the Gaussian 98 progam11
installed on the IBM RS/6000 workstations of our
laboratory and of the Universita¨tsrechenzentrum Heidel-
berg. For graphical displays we used the Molek-900012
and GaussView13 programs.
F igu r e 1. ORTEP drawing of 2b (top) and 7. The core
atoms are labeled. Ellipsoids are at the 50% probability
level. The hydrogen atoms except for H4 have been omitted
for the sake of clarity.
Ta ble 1. Selected In ter a tom ic Dista n ces (Å) for
2b a n d 7
Compound 2b
Mn-C1
Mn-C4
Mn-C5
Mn-C6
Mn-C7
Mn-C8
Mn-C9
1.812(5)
2.134(4)
2.167(4)
2.156(4)
2.115(4)
2.131(4)
3.045(5)
C1-O1
C4-C5
C5-C6
C6-C7
C4-C8
C7-C8
C8-C9
1.142(5)
1.393(6)
1.415(6)
1.389(6)
1.452(6)
1.456(5)
1.413(5)
(7) Becke, A. D. J . Chem. Phys. 1992, 96, 2155; J . Chem. Phys. 1993,
98, 5648. Vosko, S. H.; Wilk, L.; Nusair, M. Can. J . Phys. 1980, 58,
1200. Lee, C.; Yang, W.; Parr, R. G. Phys. Rev. B 1988, 37, 785.
(8) Wachters, A. J . H. J . Chem. Phys. 1970, 52, 1033.
(9) Krishnan, R.; Binkley, J . S.; Seeger, R.; Pople, J . A. J . Chem.
Phys. 1980, 72, 650.
(10) Foster, J . P.; Weinhold, F. J . Am. Chem. Soc. 1980, 102, 7211.
Reed, A. E.; Weinhold, F. J . Chem. Phys. 1983, 78, 4066. Reed, A. E.;
Weinstock, R. B.; Weinhold, F. J . Chem. Phys. 1985, 83, 735. Reed, A.
E.; Curtiss, L. A.; Weinhold, F. Chem. Rev. 1988, 88, 899.
(11) Gaussian 98, Revision A.5. Frisch, M. J .; Trucks, G. W.;
Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheeseman, J . R.;
Zakrzewski, V. G.; Montgomery, J . A., J r.; Stratmann, R. E.; Burant,
J . C.; Dapprich, S.; Millam, J . M.; Daniels, A. D.; Kudin, K. N.; Strain,
M. C.; Farkas, O.; Tomasi, J .; Barone, V.; Cossi, M.; Cammi, R.;
Mennucci, B.; Pomelli, C.; Adamo, C.; Clifford, S.; Ochterski, J .;
Petersson, G. A.; Ayala, P. Y.; Cui, Q.; Morokuma, K.; Malick, D. K.;
Rabuck, A. D.; Raghavachari, K.; Foresman, J . B.; Cioslowski, J .; Ortiz,
J . V.; Stefanov, B. B.; Liu, G.; Liashenko, A.; Piskorz, P.; Komaromi,
I.; Gomperts, R.; Martin, R. L.; Fox, D. J .; Keith, T.; Al-Laham, M. A.;
Peng, C. Y.; Nanayakkara, A.; Gonzalez, C.; Challacombe, M.; Gill, P.
M. W.; J ohnson, B.; Chen, W.; Wong, M. W.; Andres, J . L.; Head-
Gordon, M.; Replogle, E. S.; Pople, J . A. Gaussian, Inc.: Pittsburgh,
PA, 1998.
Compound 7
Mn-C1
Mn-C4
Mn-C5
Mn-C6
Mn-C8
Mn-C9
1.797(2)
2.140(2)
2.143(2)
2.144(2)
2.150(2)
3.340(2)
C1-O1
C4-C5
C5-C6
C6-C7
C7-C8
C8-C9
1.142(2)
1.414(2)
1.419(3)
1.414(2)
1.413(2)
1.518(2)
bending of the C8-C9 bond by R ) 7° (as defined in 5)
toward the metal. We notice also a bond alternation in
the fulvene ring. The bonds C4-C5 and C6-C7 are
shorter (1.39 Å) than C5-C6 (1.42 Å) and C4-C8 or
C7-C8 (1.45 Å). This alternation of the carbon bonds
is not found in the five-membered ring of 7 (Table 1).

Notes
Organometallics, Vol. 20, No. 1, 2001 229
Ta ble 3. Selected Dista n ces (Å) Resu ltin g fr om a
DF T Ca lcu la tion on 2a (Cs)
C8-C9 bond. It is calculated to be 1.36 Å in 2a ′ and
1.38 Å in 2a . The energy difference between 2a and 2a ′
was calculated to be 23 kJ /mol. In Figure 2 we present
a correlation diagram between the frontier orbitals of
2a ′ and 2a . As a result of the bending of C9 toward the
metal the LUMO is strongly destabilized due to the
antibonding interaction between the 2p orbital at C9
and the metal 3d orbital. With the exception of 1a′′ four
of the highest occupied orbitals are stabilized by the
bending (Figure 2). A population analysis yields a slight
increase of the positive charge at the metal in 2a (0.724)
as compared to 2a ′ (0.716) and at C9 a decrease (0.328
in 2a ′ and 0.175 in 2a ).
Mn-C1
Mn-C4
Mn-C5
Mn-C8
Mn-C9
1.858
2.157
2.232
2.052
2.429
C1-O1
C4-C5
C5-C6
C8-C9
1.133
1.391
1.448
1.384
Table 3 lists the most relevant distances obtained.
These data agree well with the X-ray data (Table 1),
except for the angle R. In this case we calculated 31°
whereas the experiment yielded only 6.6°. This differ-
ence might be attributed to steric effects; however, for
1b a bending angle of 31° was reported.2 It is interesting
to note that both extended Hu¨ckel14 and DFT calcula-
tions15 on 3a predict larger values for R of 40° and 41°,
respectively, whereas the diffraction studies yielded 21°
for 3b.3 In the sterically less crowded ruthenocene and
osmocene derivatives (C5Me5MC5Me4CH2+, M ) Ru, Os)
the CH2 group was bent by R ) 40.3° and 41.8°,
respectively.16
Exp er im en ta l Section
Equ ip m en t. All melting points are uncorrected. The NMR
spectra were measured with a Bruker AS 300 (1H NMR at 300
MHz and 13C NMR at 75.5 MHz) using the solvent (CD2Cl2)
for calibration (δ ) 5.31). High-resolution mass spectra
(HRMS) were obtained with a ZAB-3F (Vacuum Generators)
and J EOL J MS 700 high-resolution mass spectrometer. The
UV/vis spectra were recorded on a Hewlett-Packard HP8452
diode spectrometer. Microanalyses were performed at the
We also optimized the structure of a species with a
planar fulvene complexed to a Mn(CO)3 unit (2a ′).15 The
main difference of 2a and 2a ′ is an elongation of the
F igu r e 2. Correlation diagram between the frontier orbitals of a planar 2a ′ and a bent cation (2a ).

230 Organometallics, Vol. 20, No. 1, 2001
Notes
Ta ble 4. Cr ysta l Da ta a n d Str u ctu r e Refin em en t
for 2b a n d 7
ether/ether 9:1, Rf ) 0.26) and yielded 3.27 g (87%) of 7 as a
yellow solid. For 7: mp 122 °C; 1H NMR δ 2.72 (bs, 1H, OH),
4.69 (bs, 2H, CpH), 4.87 (bs, 2H, CpH), 7.31 (bs, 10H, ArH);
13C NMR δ 77.4 (i-CpC), 80.5 (CpCH), 87.1 (CpCH), 111.7
(COH), 127.1, 127.7, 128.0 (ArCH), 146.8 (ArC), 224.8 (CO);
UV/vis (CH2Cl2) (λmax, nm (log ꢀ)) 328 (3.1); HRMS calcd for
C21H15MnO4 m/z 386.0351, found m/z 386.0362. Anal. Calcd
for C21H15MnO4 (386.0): C, 65.30; H, 3.91. Found: C, 65.27;
H, 3.97.
7
2b
emp form
form wt
C
386.3
21H15MnO4
C54H28BCl2F24MnO3
1317.41
cryst color
cryst shape
cryst size [mm]
T [K]
yellow
polyhedron
blue
polyhedron
0.36 × 0.30 × 0.28 0.36 × 0.24 × 0.07
200
200
wavelength [Å]
cryst syst
space group
Z
0.71073
monoclinic
C2/c
0.71073
triclinic
P1h
(Tr icar bon yl){η5-(diph en yliu m )cyclopen tadien yl}m an -
ga n ese
Tet r a k is[3,5-(t r iflu or om et h yl)p h en yl]b or a t e
8
2
(2bBAr F ). To a solution of 7 (30 mg, 0.078 mmol) in 2 mL of
dry CH2Cl2 was added at room temperature 86 mg (0.086
mmol) of [3,5-(CF3)2C9H3]4B-H(OEt2)2+ (HBArF‚2Et2O)6 under
argon (glovebox). The blue solution was stirred for 10 min at
room temperature. After reduction of the volume of the
solution to 1 mL and addition of 5 mL of pentane, a blue oil
separated. The oil was suspended in 5 mL of pentane and
vigorously stirred, and then volatiles were removed in vacuo.
Repeating this procedure three times led to the formation of
a blue powder that was washed three times with 5 mL of
pentane. Drying in vacuo yielded 60 mg (60%) of 2bBAr F as
a blue microcrystalline solid. For 2bBAr F : mp 102 °C; 1H
NMR δ 5.83 (“t”, J ) 2.3 Hz, 2H, CpH), 6.11 (“t”, J ) 2 Hz,
CpH), 7.55 (bs, 4H, p-ArF-H), 7.56 (s, 4H, o-Ar-H), 7.62 (“t”,
J ) 8.3 Hz, m-Ar-H), 7.72 (bs, 8H, o-ArF-H), 7.96 (“t”, J ) 7.3
Hz, 2H, p-Ar-H); 13C NMR δ 95.8, 96.4 (CpC), 97.0 (i-CpC),
a [Å]
b [Å]
c [Å]
19.8003(3)
7.0936(1)
27.0656(2)
90.0
109.317(1)
90.0
3587.49(8)
1.43
0.76
2.2-27.5
-25 e h e 25
-9 e k e 9
-35 e l e 35
17762
12.6457(8)
14.0369(9)
16.614(1)
75.733(1)
77.770(1)
71.565(1)
2682.6(3)
1.63
R [deg]
â [deg]
γ [deg]
V [Å3]
Dcalcd [g/cm3]
abs coeff., µ [mm-1
θ range [deg]
index ranges
]
0.47
1.6-25.6
-14 e h 15
-17 e k 16
-20 e l e 19
20108
no. of reflns collected
no. of unique reflns
max and min
transmission
no of obsd data/params
GOF on F2
4116
0.86 and 0.75
8993
0.97 and 0.74
3621/236
1.06
0.031
0.082
0.34-0.36
5767/878
1.01
0.046
0.098
0.48-0.34
1
2
117.6 (p-ArFC), 124.7 (q, J C-F ) 272 Hz, CF3), 129.0 (q, J C-F
) 30 Hz, m-ArF-C), 130.2, 134.4 (o- and m-Ar-C), 134.9 (bs,
R (F)
Rw (F2)
1
o-ArF-C), 138.7 (i-ArC), 139.4 (p-Ar-C), 161.8 (q, J BC ) 50
(∆F)max, (∆F)min [eÅ-3
]
Hz, BC), 203.1 (CPh2), 217.2 (CO); UV/vis (CH2Cl2) (λmax, nm
(log ꢀ)) 266 (4.0), 390 (4.3), 614 (3.9); HRMS calcd for C21H14
MnO3 m/z 369.0323, found 369.0338. Anal. Calcd for C53H26
BF24MnO3: C, 51.65; H, 2.13. Found C, 51.65; H, 2.11.
-
-
Mikroanalytisches Laboratorium der Chemischen Institute der
Universita¨t Heidelberg.
(1-(Dip h en ylh yd r oxym et h yl)cyclop en t a d ien yl)m a n -
ga n ese Tr ica r bon yl (7). To a solution of 2.0 g (9.8 mmol) of
cymantrene (6) in 25 mL of dry ether was added at -78 °C
6.7 mL (10.8 mmol) of a 1.6 M solution of n-BuLi in hexane.
After the mixture was stirred at -78 °C for 30 min it was
warmed within 30 min to -20 °C. A color change from light
yellow to dark brown was observed. Subsequently the mixture
was cooled to -50 °C and a solution of 2.0 g (10.8 mmol) of
benzophenone in 15 mL of dry ether was added. After the
mixture was warmed to 0 °C within 3 h it was hydrolyzed with
a saturated solution of NH4Cl in water. The layers were
separated; the organic phase was washed with saturated NaCl
solution in water, dried with Na2SO4, and concentrated in
vacuo. The residue was chromatographed (alumina, petroleum
X-r a y Cr ysta llogr a p h y a n d Str u ctu r e Solu tion . Data
were collected on a Bruker SMART CCD diffractometer at 200
K. Relevant crystal and data collection parameters are given
in Table 4. The structures of 2b and 7 were solved by using
direct methods, least-squares refinement, and Fourier tech-
niques. Structure solution and refinement were performed
with SHELXTL V 5.10.17
Ack n ow led gm en t. We are grateful to the Deutsche
Forschungsgemeinschaft (SFB 247), the Fonds der
Chemischen Industrie, and the BASF Aktiengesellschaft
for financial support. M.A.O.V. acknowledges the Stu-
dienstiftung des deutschen Volkes for a fellowship. We
thank Mrs. A. Reule for typing the manuscript.
(12) Bischof, P. Molek-9000, Universita¨t Heidelberg, 1998.
(13) GaussView Gaussian, Inc.: Pittsburgh, PA, 1998.
(14) Gleiter, R.; Seeger, R. Helv. Chim. Acta 1971, 54, 1217.
(15) Hyla-Kryspin, I.; Gleiter, R. Unpublished results.
(16) Rybinskaya, M. I.; Kreindlin, A. Z.; Struchkov, Y. T. Yanovsky,
A. I. J . Organomet. Chem. 1989, 359, 233; Yanovsky, A. I.; Struchkov,
Y. T.; Kreindlin, A. Z.; Rybinskaya, M. I. J . Organomet. Chem. 1989,
369, 125.
Su p p or tin g In for m a tion Ava ila ble: Tables of atomic
coordinates and thermal parameters, and bond lengths and
angles for 2b and 7. This material is available free of charge
via the Internet at http://pubs.acs.org.
(17) Sheldrick, G. M. SHELXTL V 5.10; Bruker Analytical X-ray
Division: Madison, WI, 1997.
OM000587Q