Unexpectedly different reactions of [(arene)Mn(CO)3]+ cations (arene = trindane, indane, tetralin, or dibenzosuberane) with potassium t-butoxide - C-H insertions, haptotropic shifts, dimerization, or elimination

Article abstract of DOI:10.1139/V08-122

[(η⁶-Trindane)Mn(CO)₃][BF₄] (1) reacts with tert-BuOK in THF in the presence of alkyl halides (CH₂= CHCH₂Br, CH₃I) to yield the corresponding (η⁶-C₁₅H₁₈)Mn(

Full text of DOI:10.1139/V08-122

232
Unexpectedly different reactions of
[(arene)Mn(CO)3]+ cations (arene = trindane,
indane, tetralin, or dibenzosuberane) with
potassium t-butoxide — C-H insertions,
haptotropic shifts, dimerization, or elimination1
Nada Reginato, Laura E. Harrington, Yannick Ortin, and Michael J. McGlinchey
6
Abstract: [(η -Trindane)Mn(CO)3][BF4] (1) reacts with tert-BuOK in THF in the presence of alkyl halides
6
(CH2=CHCH2Br, CH3I) to yield the corresponding (η -C15H18)Mn(CO)2X, where X = Br (3) or I (4). In contrast, 1 and
5
tert-BuOK react, in the presence of a donor ligand, to generate (η -C15H15)Mn(CO)2L, where L = CO (7), P(OMe)3
(8), or PPh3 (9), in which the metal has migrated from the central ring onto a peripheral ring that has lost three hydro-
6
6
gens; [(η -indane)Mn(CO)3][BF4] behaves similarly. A mechanism is proposed in which the initially formed (η -
6
trindane)Mn(CO)2CO2-tert-Bu suffers the loss of CO2 and isobutene to yield the hydride, (η -trindane)Mn(CO)2H, that
in turn undergoes three successive C-H insertions with concomitant loss of two molecules of dihydrogen. In contrast,
6
6
[(η -tetralin)Mn(CO)3][PF6] (17) and [(η -dibenzosuberane)Mn(CO)3][BF4] (23) each suffer deprotonation at a benzylic
5
site. In the first case, the zwitterion formed attacks its progenitor to yield a tetralenyl-substituted (η -cyclohexadienyl)Mn(CO)3
complex (21); however, for the dibenzosuberane complex (23) the elimination product (28) is stable. X-ray crystal
6
structures are reported for 3, 4, 7, 8, 23, 28, and for the phosphite complexes [(η -trindane)Mn(CO){P(OMe)3}2][BF4]
(15) and [(η -tetralin)Mn(CO)2{P(OMe)3}][PF6] (20).
6
Key words: arene–manganese, organometallic cations, deprotonations, X-ray crystallography.
6
Résumé : Le [(η -trindane)Mn(CO)3[BF4] (1) réagit avec le tert-BuOK, dans le THF, en présence d’halogénures
6
d’alkyles (CH2=CHCH2Br et le CH3I) pour conduire à la formation des (η -C15H18)Mn(CO)2X dans lesquels X = Br
(3) ou I (4). Par opposition, le composé 1 réagit avec la tert-BuOK, en présence d’un ligand donneur, pour générer les
5
complexes (η -C15H15)Mn(CO)2L dans lesquels L = CO (7), P(OMe)3 (8) ou PPh3 (9) alors que le métal a migré du
6
noyau central vers un noyau périphérique avec perte de trois atomes d’hydrogène; Le [(η -indane)Mn(CO3][BF4] se
6
comporte de la même manière. On propose un mécanisme dans lequel l’entité (η -trindane)Mn(CO)2CO2-tert-Bu subit
6
une perte de CO2 et d’isobutène pour fournir l’hydrure (η -trindane)Mn(CO)2H qui subit à son tour trois insertions suc-
6
cessives de C-H avec la perte concomitante de deux molécules de dihydrogène. Par ailleurs, le [(η -tétra-
6
line)Mn(CO)3][PF6] (17) et le [(η -dibenzosubérane)Mn(CO)3[BF4] (23) subissent chacun une déprotonation au niveau
du site benzylique. Dans le premier cas, le zwitterion qui est formé attaque son progéniteur pour conduire à la forma-
5
tion d’un complexe (η -cyclohexadiényl)Mn(CO)3 portant un substituant tétralényle (21); toutefois, pour le complexe
avec le dibenzosubérane (23), le produit d’élimination (28) est stable. Faisant appel à la diffraction des rayons X, on a
déterminé et on décrit les structures cristallines des composés 3, 4, 7, 8, 23 et 28 ainsi que celles des complexes de
6
6
phosphite, [(η -trindane)Mn(CO){P(OMe3}2][BF4] (15) et [(η -tétraline)Mn(CO)2{P(OMe3}][BF6] (20),
Mots-clés : arène-manganèse, cations organométalliques, déprotonations, cristallographie par diffraction des rayons X.
[Traduit par la Rédaction] Reginato et al. 246
Received 31 March 2008. Accepted 14 May 2008. Published on the NRC Research Press Web site at canjchem.nrc.ca on 3 October
2008.
This article is dedicated to Professor Richard Puddephatt, an outstanding chemist, an inspiring teacher, and a valued friend.
N. Reginato and L.E. Harrington. Department of Chemistry, McMaster University, Hamilton, ON L8S 4M1, Canada.
Y. Ortin and M.J. McGlinchey.2 School of Chemistry and Chemical Biology, University College Dublin, Belfield, Dublin 4,
Ireland.
1This article is part of a Special Issue dedicated to Professor Richard J. Puddephatt.
2Corresponding author (e-mail: michael.mcglinchey@ucd.ie).
Can. J. Chem. 87: 232–246 (2009)
doi:10.1139/V08-122
© 2008 NRC Canada

Reginato et al.
233
iodide again led to extensive multiple alkylation, and mass
spectrometric data indicated the incorporation of at least ten,
and possibly twelve, allyl or methyl substituents. After many
attempts to obtain a sample of the polymethylated complex
appropriate for an X-ray study, data sets were acquired on
several crystals of rather poor quality, but disorder problems
have so far prevented the satisfactory resolution of these
structures.
Introduction
As part of a program directed towards an organometallic
route to sumanene (1), we began to develop the organo-
metallic chemistry of tri(cyclopentano)benzene (trindane) (2,
3), a tetracyclic substructure of the target molecule. To this
end, we chose to attempt the alkylation of all six exo-
6
benzylic positions of (η -trindane)MLn using the now classic
Astruc methodology (4). Since Eyman and co-workers (5)
have already shown that [(hexamethylbenzene)Mn(CO)3]+
readily undergoes abstraction of a benzylic proton to yield
the corresponding cyclohexadienyl system that reacts with
electrophiles to functionalize the benzylic site (5), we de-
Reactions of [(␩6-trindane)Mn(CO)3][BF4]
Since an M(CO)3 moiety (M = Cr, Mn) has been shown to
generate a larger cone angle than an Fe(C5H5) fragment (11),
6
+
cided to study the reactions of [(η -trindane)Mn(CO)3] [BF4]
the tripodal group Mn(CO)3 was selected as an activating
6
(1) and [(η -trindane)Fe(C5H5)][PF6] (2) with potassium
agent, not only to enhance the acidity at the benzylic posi-
tions but in addition to act as a stereodirecting group by
blocking one π-face of the arene ligand. Consequently, our
focus switched to the manganese cation, 1, which, when
mixed with tert-BuOK as dry solids, and then treated with
excess allyl bromide in THF furnished after chromatographic
separation a deep red crystalline material whose NMR, mass,
tert-butoxide, and subsequently with alkyl halides. However,
as reported in a preliminary communication (6), the reac-
tions of 1 led to unexpected rearrangement products. We
now describe these studies more fully, and also report how
6
the reactions have been extended to the analogous [(η -
arene)Mn(CO)3]+ systems, whereby the five-membered rings
in trindane or indane have been replaced by six- and seven-
membered rings in tetralin and dibenzosuberane, respectively.
6
and IR spectra indicated it to be (η -trindane)Mn(CO)2Br
(3). The analogous reaction of 1, tert-BuOK, and methyl io-
6
dide gave the corresponding (η -trindane)Mn(CO)2I (4).
The X-ray crystal structures of 3 and 4 appear in Figs. 1a
and 1b, respectively, and are reminiscent of the geometry
6
previously reported for (η -C6Me6)Mn(CO)2Cl whereby the
tripod is staggered relative to the alkyl substituents (12).
Moreover, the cyclopentene rings in 3 (and 4) adopt enve-
lope conformations such that the “wingtip” methylene
groups are folded endo with respect to the plane of the cen-
6
tral six-membered ring, as was previously found in both (η -
6
Results and discussion
trindane)Cr(CO) and [( -trindane)RuCl {P(OMe) }] (2, 3).
η
3
The structures of 3 and 4 may also be 2compared3 with the
The activation of benzylic sites by incorporation of a π-
complexed organometallic moiety is a well-established phe-
nomenon, and has been attributed to a combination of the
electron-withdrawing effect of the metal and the resonance
stabilization of the conjugate base (7). Typically, molecules
known complexes [tri(cyclohexano)benzene]MLn, where
+
MLn = Cr(CO)3 or Mn(CO)3 , whereby the M(CO)3 unit dis-
plays the typical staggered orientation and the peripheral
rings exhibit the “half-boat” conformation (13).
Another structural feature of interest for compounds 3 and
4 is that, in each case, the central ring is slightly folded such
that the arene carbons C(1) and C(2), trans to the halogen
atom, are slightly closer to the manganese atom than are the
other four carbons [i.e., C(3), C(4), C(5), C(6)]. Whether
this folding is attributable to packing effects, or to the
weaker trans influence of the halide, is not clear; however, it
6
of the type (η -arene)MLn, where MLn is Cr(CO)3,
+
Mn(CO)3 , or Fe(C5H5)+, undergo ready deprotonation at
benzylic positions; subsequent treatment with alkyl halides
leads to attack at the benzylic site. Particularly elegant ex-
amples are provided by Jaouen et al.’s (8) specific
functionalization at the 6β position in (3-methoxyestradiol)[
α-Cr(CO)3], and by Astruc’s (9) systematic construction of
organometallic dendrimers. Another very ingenious applica-
tion that takes advantage of the steric blocking of one face
of the arene by a metal tripod is the preparation of an artifi-
cial receptor, whereby trindane was benzylated at the three
exo-wingtip positions (10).
6
parallels the folding found in (η -C6Me6)Mn(CO)2Cl. The
manganese atoms in 3 and 4 are located 1.677 and 1.678 Å,
respectively, below the centroid of the six-membered ring,
6
slightly closer than is found in (η -C6Me6)Mn(CO)2Cl
(1.706(3) Å) (12). The Mn–CO bond lengths are normal
(1.781(8)–1.802(10) Å), the Mn-C-O angles are slightly less
than 180°, and the Mn-ring-carbon distances range from
2.133(7) to 2.230(4) Å.
Reactions of [(␩6-trindane)Fe(C56H5)][PF6]
In light of these precedents, [(η -trindane)Fe(C5H5)][PF6]
(2) and tert-BuOK were mixed as dry solids and then treated
with excess allyl bromide (or methyl iodide) in THF in the
hope that all six exo-benzylic sites would be alkylated. In a
previous study (2), we had noted that the corresponding re-
action of 2 and tert-BuOK in the presence of DMSO-d6
yielded dodeca-deuterated 2 as the major product; that is, all
twelve benzylic positions, both exo and endo, had undergone
exchange. Interestingly, use of either allyl bromide or methyl
As expected, the carbonyl IR stretching frequencies in the
6
series (η -trindane)Mn(CO)2X decrease as a result of the
transformation from a cationic to a neutral species: X = Cl
(1980, 1931 cm–1), X = Br (1971, 1927 cm–1), X = I (1973,
6
1926 cm–1). The starting material, [(η -trindane)Mn(CO)3][BF4]
(1) exhibits carbonyl stretches at 2056 and 1997 cm–1. These
6
data are similar to the νCO values previously reported for (η -
C6Me6)Mn(CO)2X complexes: 1972, 1920 cm–1; 1971,
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234
Can. J. Chem. Vol. 87, 2009
Scheme 1. Proposed mechanism of formation of 3 and 4.
6
Fig. 1. (a) The molecular structure of (η -trindane)Mn(CO)2Br
(3) showing the staggered orientation of the tripodal Mn(CO)2Br
moiety. (b) The molecular structure of (η -trindane)Mn(CO)2I (4)
6
illustrating the envelope conformation of the peripheral rings.
Thermal ellipsoids are shown at the 30% probability level.
more reactive than (C6Me6)Mn(CO)2H towards alkyl
halides.
Although it is well established that (C6Me6)Mn(CO)2H
can be prepared by treatment of (C6Me6)Mn(CO)2Br with
6
[Bu4N][BH4] (12), numerous attempts to synthesize (η -
trindane)Mn(CO)2H from the corresponding bromide 3 by
this route, or to detect the hydride signal by NMR at low
temperature, were unsuccessful. Consequently, we chose to
try to intercept the purported hydride 5, either as
(trindane)Mn(CO)(PR3)H, or as the formyl complex
(trindane)Mn(CO)(CHO)(PR3), in the absence of RBr.
When the cation 1 and tert-BuOK were treated with
trimethyl phosphite in THF and allowed to stir at 40 °C for
20 h, to our surprise, the two products isolated after chro-
matographic separation, were yellow crystalline materials 7
1
and 8 whose H and 13C NMR spectra indicated that the
three-fold symmetry of the trindane ligand had been broken.
The mass spectra of 7 and 8 exhibited parent peaks at m/z =
334 and 430, respectively, indicating a molecular formula of
(C15H15)Mn(CO)2L, where L = CO for 7, and L = P(OMe)3
for 8. Both products were definitively characterized by X-
5
ray crystallography as η -indenyl complexes in which the
manganese has migrated from the central arene onto a five-
membered ring that has evidently lost three hydrogens. The
analogous complex (9), where L = PPh3, is also accessible in
1921 cm–1; and 1968, 1920 cm–1; where X = Cl, Br, and I,
respectively (12).
6
this manner. Likewise, the corresponding reactions of [(η -
indane)Mn(CO)3][BF4] (10) and tert-BuOK yield the known
5
Since replacement of a carbonyl by a phosphine or a ha-
complexes (η -indenyl)Mn(CO)2L, where L = P(OMe)3 or
6
lide in [(η -C6Me6)Mn(CO)3]+ normally requires either
PPh3 (18). The IR spectra of 7 (νCO absorptions at 2016 and
1934 cm–1) and 8 (νCO at 1944 and 1876 cm–1) each exhibit
two carbonyl bands, and are in accord with those of the
photolysis or use of Me3NO (14, 15), it was somewhat sur-
6
prising that the formation of the (η -trindane)Mn(CO)2X
5
species, 3 and 4, should have occurred so readily. Moreover,
closely analogous systems (η -C5H5)Mn(CO)3 (νCO at 2025
6
6
5
and 1938 cm–1) and (η -C5H5)Mn(CO)2[P(OMe)3] (νCO at
because (η -C6Me6)Mn(CO)2H is known to yield (η -
C6Me6)Mn(CO)2Cl in the presence of CCl4 or CHCl3 (but
not CH2Cl2) (12), one is tempted to invoke the intermediacy
1948 and 1884 cm–1).
The structures of the rearranged molecules 7 and 8 are
shown in Figs. 2a and 2b, respectively, and reveal in each
case a “piano stool” structure with the Mn(CO)2L tripod co-
6
of (η -trindane)Mn(CO)2H (5). Eyman and co-workers (16)
6
have shown that (η -C6Me6)Mn(CO)2I reacts with tert-
6
5
butyllithium to yield thermally stable (η -C6Me6)Mn(CO)2H,
ordinated in an η -fashion to a peripheral five-membered
apparently via loss of isobutene from the presumed tert-
ring. The manganese atoms in 7 and 8 lie 1.824 and 1.797 Å,
respectively, below the centroid of the five-membered ring.
The Mn-to-cyclopentadienyl-carbon distances range from
2.114(2) to 2.235(2) Å, and are comparable to those reported
butyl intermediate. Furthermore, as the cationic complexes
6
[(η -arene)Mn(CO)3]+, (arene = C6H6 or C6Me6), are known
to react with methoxide in methanol to yield the rather un-
6
5
stable esters, (η -arene)Mn(CO)2CO2Me (17), one might
for (η -cyclopenta[def]phenanthrenyl)Mn(CO)3 (19).
propose that a reaction between 1 and tert-BuOK could gen-
erate the tert-butyl ester (6) that readily eliminates both iso-
butene and carbon dioxide via a very favorable six-
membered transition state to produce 5, as depicted in
Scheme 1. Interestingly, treatment of 1 with tert-BuOK in
In Scheme 2, a mechanistic rationale to account for these
novel products is offered. We suggest that in the absence of
an alkyl halide, the initially generated (trindane)Mn(CO)2H (5)
undergoes a hydrogen migration (presumably via an agostic
interaction) from an endo-benzyl site onto the metal thus
producing the cyclohexadienyl complex (11) that in turn
6
CH2Cl2 gave (η -trindane)Mn(CO)2Cl, suggesting that 5 is
© 2008 NRC Canada

Reginato et al.
235
Fig. 2. (a) Molecular structure of (C15H15)Mn(CO)3 (7). (b) Mo-
lecular structure of (C15H15)Mn(CO)2[P(OMe)3] (8). Thermal el-
lipsoids are shown at the 30% probability level.
Scheme 2. Proposed mechanism of formation of 7, 8, and 9.
Scheme 3. “Ricochet” inter-ring haptotropic rearrangement.
cyclopentadiene ring and provide some justification for the
structures 12 and 13 proposed in Scheme 2.
Other (trindane)ML3 complexes (M = Mn, Re)
With the aim of selectively deprotonating only the exo-
benzylic positions of trindane, we chose to replace one or
more of the carbonyl ligands in 1 with somewhat more
sterically demanding phosphite substituents, even though
such an approach could diminish the acidic character of the
6
benzylic sites. Thus, treatment of [(η -trindane)Mn-
(CO)3][BF4] (1) with trimethyl phosphite and trimethyl-
amine N-oxide furnished a yellow crystalline solid that was
characterized spectroscopically and by X-ray crystallogra-
6
phy as [(η -trindane)Mn(CO){P(OMe)3}2][BF4] (15). The IR
spectrum displayed a single carbonyl stretch at 1911 cm–1,
6
similar
to
that
previously
reported
for
[(η -
C6Me6)Mn(CO){P(OMe)3}2][PF6] (14). Figure 3a depicts
the cationic portion of 15, which has the conventional piano
stool structure typical of half-sandwich complexes; the car-
bonyl and the two trimethyl phosphite ligands adopt a stag-
gered conformation relative to the carbon atoms of the arene
ring, and the manganese atom is located 1.724 Å below the
centroid of the arene. The Mn–C (arene) bond lengths range
from 2.194(4) to 2.237(3) Å, the Mn-CO and two Mn-P dis-
tances are 1.772(4), 2.1996(12), and 2.2174(14) Å, respec-
tively, and the Mn-C-O angle is reduced to 173.9(4)°. As far
as we are aware, the only other (arene)manganese-bis-
phosphite complex to have been crystallographically charac-
loses dihydrogen to give 12. A second endo-benzyl hydro-
gen migration to yield the isoindene framework (13) is fol-
lowed by the final hydrogen migration producing 14. Loss
of dihydrogen and incorporation of either a carbonyl or a
phosphite ligand would give the observed products 7 or 8,
respectively.
6
terized is [(η -toluene)Mn(CO){P(OEt)3}2][PF6] (22); the
6
2
bis-chelated di-tertiary phosphine, [(η -C6H6)Mn(CO){η -
5
PPh2(CH2)3PPh2}][PF6]·2CH3CN and (η -C6Me6H)Mn-
(CO)[P(OMe)3]2 have also been reported (23, 24).
In seeking a precedent for the proposal outlined above, we
note the report by Crabtree and Parnell (20) wherein
Figure 3b shows a space-filling view of 15 that
emphasises the degree of crowding on the endo side of the
complexed trindane ligand, thus restricting access to that
face. However, because of the rather poor yield (11%) of 15,
deprotonation or other further reactions of this system were
not investigated. This low yield follows the trend observed
6
[(η -indane)Ir(PPh3)2]+ undergoes dehydrogenation and an
6
5
5
η -to-η haptotropic shift at 80 °C to furnish [(η -
indenyl)Ir(PPh3)2(H)]+. Moreover, Ustynyuk and co-workers
(21) have shown that (η -indenyl)Cr(CO)3Me undergoes a
5
6
“ricochet reaction” in which the methyl is delivered onto the
five-membered ring and the tricarbonylchromium fragment
migrates to the six-membered ring, as depicted in Scheme 3.
Density functional theory calculations by these workers indi-
cate that the reaction proceeds through an isoindene struc-
ture in which the chromium is bonded to the diene portion of
the six-membered ring and one double bond of the
for analogous compounds such as [(η -toluene)Mn-
(CO){P(OR)3}2][PF6] where R is Me or Et (22). Likewise,
6
treatment of [(η -toluene)Mn(CO)3][PF6] with Me3NO and
PPh3 failed to bring about substitution of the carbonyl
groups by triphenylphosphine (24).
6
In the hope that the hydride (η -trindane)Re(CO)2H might
show enhanced stability relative to its manganese counter-
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236
Can. J. Chem. Vol. 87, 2009
6
6
Fig. 3. (a) Molecular structure of the cation [(η -trindane)Mn-
(CO){P(OMe)3}2]+ (15). Thermal ellipsoids are shown at the
30% probability level. (b) Space-filling view of 15 accentuating
the degree of crowding induced by the tripodal fragment.
Scheme 4. Reactions of [(η -tetralin)Mn(CO)3]+ (17) with
nucleophiles.
6
change furnished [(η -tetralin)Mn(CO)3][PF6] (17) in 80%
yield. We are aware of only one report on the reactivity of
the cation 17, whereby Lee and co-workers (25) found that
nucleophilic addition afforded adducts at the α-position, as
in 18, except when treated with MeMgBr in THF at 0 °C,
which also yielded the acyl compound 19 (Scheme 4). Re-
lated studies by Sweigart and co-workers (26) on hormonal
steroidal systems bearing a [Mn(CO)3]+ moiety on the aro-
matic A ring likewise underwent exo addition at C-1 when
treated with a range of nucleophiles.
6
The reaction of [(η -tetralin)Mn(CO)3][PF6] (17) with
tert-BuOK and P(OMe)3 in THF gave, even after repeated
chromatographic separations, multiple products each in such
low yield as to preclude definitive identification. As a result
of the complexity of the reaction, it was decided to investi-
gate the effects of each reagent separately to help clarify
their roles in the overall reaction. When trimethyl phosphite
6
in THF was added to [(η -tetralin)Mn(CO)3][PF6] in the
dark, no change was observed, as monitored by in situ IR
spectroscopy. However, when exposed to sunlight, the reac-
tion yielded a yellow crystalline solid that was identified by
6
1H, 13C, and 31P NMR and mass spectrometry as [(η -
tetralin)Mn(CO)2{P(OMe)3}][PF6] (20); the assignment was
verified by means of a single crystal X-ray diffraction study.
The molecule exhibited carbonyl IR stretches at 2008 and
1961 cm–1, and 31P NMR resonances for each of the phos-
phorus environments, i.e., for the trimethyl phosphite ligand
and the hexafluorophosphate anion.
As shown in Figs. 4a and 4b, the tripodal
[Mn(CO)2{P(OMe)3}] unit lies in an essentially staggered
orientation, typical of such polycyclic manganese complexes
(26). The cyclohexene ring adopts a twisted half-chair con-
formation, with one of the homobenzylic ring carbon atoms
lying below, and the other lying above, the molecular plane
defined by the arene ring, which is itself planar. The manga-
nese atom is located 1.679 Å below the plane of the arene
ring, and the Mn-C(arene) distances range from 2.179(2) to
2.207(2) Å. The hexafluorophosphate anion was disordered,
and two orientations were found.
part 5, it was deemed worthwhile to attempt the synthesis of
6
the analogous [(η -trindane)Re(CO)3]+ cation (16). Indeed,
16 can be prepared from BrRe(CO)5, AlCl3, and trindane,
but the yield, as is sometimes the case with arene–rhenium
6
complexes (14), is very poor (2%). Nevertheless, the [(η -
trindane)Re(CO)3]+ cation was readily characterized by IR
(νCO at 2058 and 1966 cm–1) and by electrospray mass spec-
trometry, which gave rise to distinctive molecular ion peaks
at m/z 467 and 469 that exhibited the 37:63 isotopic abun-
dance ratio diagnostic for the presence of 185Re and 187Re.
X-ray crystal structures of related systems in which the
tetralin fragment is bound to a Cr(CO)3 moiety have been
reported by Schmalz and co-workers (27). Moreover, these
workers investigated the regioselectivity of the
deprotonation/alkylation process. Their data revealed that, in
the case of two competing exo hydrogen atoms having com-
parable steric environments, it is not necessarily the exo-
benzylic hydrogen atom that adopts a pseudoaxial position
that is preferentially abstracted. It was concluded that the
conformation of the chromium tricarbonyl tripod may influ-
ence the regioselectivity of benzylic deprotonation in chiral
(arene)Cr(CO)3 complexes (27), as had been suggested pre-
viously (28).
1
Moreover, the H NMR spectrum exhibited the four chemi-
cal environments characteristic of trindane metal carbonyl
complexes.
Reactions of [(␩6-tetralin)Mn(CO)3][PF6]
To probe the generality of the reaction leading to forma-
6
tion of a hydride intermediate, as in (η -trindane)Mn(CO)2H,
and the possibility of dehydrogenation concomitant with a
haptotropic shift, the corresponding six-membered tetra-
hydronaphthalene (tetralin) system was synthesized and
treated with potassium tert-butoxide and trimethyl
phosphite. Following the literature precedent (25), tetralin
was treated with bromo(pentacarbonyl)manganese in the
presence of aluminum trichloride; subsequent anion ex-
6
Treatment of [(η -tetralin)Mn(CO)3][PF6] (17) with potas-
sium tert-butoxide in THF afforded a yellow-orange oil that,
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Reginato et al.
237
6
Fig. 4. (a) Molecular structure of the cation in [(η -tetralin)Mn-
(CO)2{P(OMe)3}][PF6] (20); (b) Bird’s eye view of 20 illustrates
the staggered orientation of the tripodal manganese fragment.
Thermal ellipsoids are shown at the 30% probability level.
Scheme 5. Proposed mechanism for the formation of 21.
Scheme 6. Possible rearrangement reactions of 23 and 25.
Reactions of [(␩6-dibenzosuberane)Mn(CO)3][BF4]
In light of the previously described reactions of the
6
6
cations [(η -trindane)Mn(CO)3]+ (1) and [(η -indane)Mn-
(CO)3]+ (10) with tert-BuOK and P(OMe)3, whereby
dehydrogenation of a five-membered ring and concomitant
5
haptotropic shifts yield η complexes, we chose to extend
this study to include systems in which the manganese-
complexed arene ring was joined to a seven-membered ring.
If the reaction of [(η -dibenzosuberane)Mn(CO)3][BF4], 23,
were to proceed in a manner analogous to that of the
6
trindane system, 1, then one might anticipate loss of three
5
hydrogen atoms from the central ring and formation of a (η -
dibenzocycloheptatrienyl)Mn(CO)3 complex, such as 24,
which might exhibit a fluxional process (Scheme 6) that
would equilibrate the two six-membered rings. It has previ-
6
ously been reported that deprotonation of (η -benzo-
6
5
despite repeated efforts, did not yield a crystalline product.
Nevertheless, the mass spectrometric and IR data provide
strong evidence that the product may be assigned as the
tetralenyl-substituted cyclohexadienyl manganese complex
21. Carbonyl IR absorptions at 2007 and 1927 cm–1 (neat)
are indicative of a (cyclohexadienyl)Mn(CO)3 system. For
example, nucleophilic attack on [(tetralin)Mn(CO)3]+ by hy-
dride, methyl, or phenyl gave the 4-exo-substituted com-
pounds (18) that exhibited νCO peaks (in NaCl) at
2000/1910 cm–1, 2000/1920 cm–1, and 2004/1916 cm–1, re-
spectively, (25). Chemical ionization data for 21 revealed an
[M + H]+ peak at m/z 403, followed by loss of 131 corre-
sponding to C10H11. Subsequent fragmentation revealed the
presence of a tricarbonylmanganese moiety. Because of con-
cycloheptatriene)Cr(CO)3 leads to an η -to-η haptotropic
shift such that the metal, which was originally located on the
5
arene ring, is now bonded in an η fashion in the seven-
membered ring (29). If an analogous migration were to oc-
6
cur upon deprotonation of [(η -dibenzosuberene)Mn(CO)3]+,
25, the centrally bonded manganese in 24 would presumably
5
exhibit fluxionality, as does (η -C7H7)Mn(CO)3 (30).
6
To this end, [(η -dibenzosuberane)Mn(CO)3][BF4] (23)
was prepared by reaction of dibenzosuberane, bromopenta-
carbonylmanganese, and silver tetrafluoroborate in dichloro-
methane and was characterized spectroscopically and by
X-ray crystallography. Electrospray mass spectrometry re-
vealed a parent ion at m/z 333, with fragmentation peaks at
277 and 249 corresponding to loss of two and three carbon-
yls, respectively. The carbonyl IR stretching vibrations peaks
at 2065 and 2014 cm–1 are typical of arene–manganese
1
siderable peak overlap, the H and 13C NMR spectra of 21
have not yet been fully assigned unequivocally, however, ef-
forts to grow X-ray quality crystals are continuing.
1
tricarbonyl cations, and the H and 13C NMR spectra reveal
A straightforward mechanistic proposal to account for the
formation of 21 is depicted in Scheme 5. Deprotonation of
the presence of one coordinated and one uncoordinated
arene ring, and three methylene groups; in each case the
methylene protons are rendered nonequivalent by the pres-
ence of the metal tripod on one face of the molecule. The X-
ray crystal structure of 23 is shown in Figs. 5a and 5b and
reveals that the [Mn(CO)3] fragment is situated on the con-
6
[(η -tetralin)Mn(CO)3][PF6] by tert-BuOK to yield the zwit-
5
terionic species 22 (perhaps better represented by the η
structure 22a) can be followed by nucleophilic attack on 17;
subsequent loss of the [Mn(CO)3]+ moiety leads directly to 21.
© 2008 NRC Canada

238
Can. J. Chem. Vol. 87, 2009
6
5
Fig. 5. (a) Molecular structure of the [(η -dibenzosuberane)Mn-
(CO)3]+ cation in 23, illustrating the positioning of the Mn(CO)3
tripod on the concave face of the ligand. (b) Bird’s eye view
showing the eclipsed orientation of the tripod. Thermal ellipsoids
are shown at the 30% probability level.
Fig. 6. Molecular structure of (η -C15H13)Mn(CO)3 (28); thermal
ellipsoids are shown at the 30% probability level.
not lead to substitution of a carbonyl ligand, the reaction of
23 with tert-BuOK in THF gave as the major product an or-
ange powder exhibiting carbonyl IR absorptions at 2022 and
1950 cm–1 and a parent peak in the mass spectrum at m/z
332. This material was characterized by X-ray crystallogra-
5
cave face of the tricyclic dibenzosuberane skeleton. The
interplanar angle between the two arene rings in 23 is 129°,
somewhat larger than the corresponding angle (123°) found
in uncomplexed dibenzosuberane (31).
phy as (η -C15H13)Mn(CO)3 (28), in which deprotonation of
the benzylic proton had occurred resulting in generation of a
double bond in the central seven-membered ring. The struc-
ture of compound 28 appears in Fig. 6 and shows that the
5
This result contrasts with the structures of the previously
metal tripod is coordinated in an η -fashion to one of the
6
6
reported (η -dibenzosuberane)Cr(CO)3 and (η -dibenzo-
outer six-membered rings, such that the manganese is lo-
cated 1.718 Å below the ring.
suberone)Cr(CO)3 in which the metal tripod lies on the exo
(convex) side of the ligand, but follows the example of (η -
6
The manganese-dienyl carbon bond distances in 28 range
from 2.126(5) to 2.287(5) Å, typical for cyclohexadienyl
manganese complexes, while the C(1)–C(15) bond length of
1.358(6) Å is significantly shorter than C(1)–C(6) (1.468(6) Å),
and indicates double bond character. The carbon–carbon dis-
tances of the cyclohexadienyl ring average 1.407 Å and the
cyclohexadienyl unit exhibits a deviation from planarity of
only 0.002 Å, but the distortion from planarity of the
cyclohexadienyl ring, i.e., the angle between planes C(2)-
C(3)-C(4)-C(5)-C(6) and C(2)-C(1)-C(6) is 31°. This dihed-
dibenzosuberanol)Cr(CO)3, which, like 23, places the metal
on the endo (concave) face (32). In the manganese case, this
preference for the concave face may be a consequence of the
need to pack both the organometallic cation and the
tetrafluoroborate counterion as efficiently as possible.
It is common for polycyclic molecules that are π-
complexed to metal fragments to fold away from the metal:
examples include both α- and β-Cr(CO)3 complexes of O-
methyl podocarpate (33), as well as ruthenium (34), chro-
mium (35), and manganese (26) derivatives of estradiol and
estrone. Other crystallographically characterized molecules
that contain manganese and the suberane skeleton are the
5
ral angle θ is smaller than is found in (η -C6H7)Mn(CO)3
5
(43°) (37) or endo-(η -C6Me6H)Mn(CO)2{P(OMe)3} (47.5°)
(14) but is similar to those observed in the polycyclic sys-
tems 29 and 30, derived from naphthalene or anthracene, in
which the cyclohexadienyl ring is bent through 36° and 33°,
respectively (38, 39).
2
carbene complex, 26, and the η -ketene derivative, 27 (36).
Treatment of the (dibenzosuberane)tricarbonylmanganese
cationic complex (23) with potassium tert-butoxide and
trimethyl phosphite yielded, after chromatographic separa-
tion, a number of products in quantities too small to charac-
terize unambiguously. Consequently, as was done in the case
6
The product derived from the reaction of [(η -dibenzo-
suberane)Mn(CO)3][BF4] (23) with potassium tert-butoxide
6
is reminiscent of the behavior of the [(η -fluorene)MLn]+
6
of [(η -tetralin)Mn(CO)3][PF6], each reagent was treated sep-
cation (31) [MLn = Fe(C5H5) or Mn(CO)3], which upon
6
5
arately with [(η -dibenzosuberane)Mn(CO)3][BF4]. Al-
deprotonation yielded (η -fluorenyl)MLn, (32) (40, 41). In
though, in the absence of light, trimethyl phosphite alone did
principle, these neutral molecules can be represented either
© 2008 NRC Canada

Reginato et al.
239
Scheme 7. Haptotropic shifts in polycyclic systems.
as zwitterions or as possessing a formal double bond in the
central ring, as in 32′. However, the X-ray crystal structures
probably favored the latter interpretation in which the cyclo-
hexadienyl ring is folded through 11° (Fe) or 15° (Mn), and
the bond from the ring junction carbon to the benzylic
carbon is 1.38 Å (Fe) (40) or 1.37 Å (Mn) (41). The
cally to be 3.13 Å, but such a process requires a flattening of
the six-membered ring and an elongation of the C–H bond.
6
(fluoradene)Ru(C5Me5) complexes 33 and 34 behave simi-
The transformation of (η -trindane)Mn(CO)2H (5) into
5
5
larly (42). When (η -fluorenyl)MLn (32), where MLn
=
(η -C15H15)Mn(CO)3 (7) involves C-H and Mn-H cleavage
Mn(CO)3 or Fe(C5H5), is heated, the organometallic moiety
undergoes haptotropic shift onto the central five-
with concomitant formation of a manganese–carbonyl bond
and two molecules of dihydrogen. The requisite bond ener-
gies are BE(C-H) 413 kJ mol–1, BE(Mn-H) 288 kJ mol–1
[calculated value (45)], BE(H-H) 436 kJ mol–1, and BE(Mn-
CO) ~190 kJ mol–1(46). Thus, cleavage of three C–H bonds
and one Mn–H bond has an energy cost of approximately
1527 kJ mol–1 of which only ~1060 kJ mol–1 are recovered
as one Mn–CO and two H–H bonds. The overall free energy
change must be controlled by the stronger bonding of the
manganese to the five-membered ring and, of course, by the
very favorable increase in entropy brought about by the lib-
eration of two moles of dihydrogen.
a
membered ring to produce 35 (41). As shown in Scheme 7,
analogous behavior has also been reported for the (8,9-
dihydrocyclopenta[def]phenanthrenyl)Mn(CO)3 complexes
6
5
36 and 37 (19). Interestingly, the η -to-η haptotropic shift
of the organometallic fragment in the (cyclopenta[def]phen-
anthrenyl)Mn(CO)3 complexes 38 and 39 occurs readily at
–40 °C, and this has been rationalized in terms of the en-
hanced aromatic character of the transition state (43).
Why are the reactions so different?
6
The complex [(η -trindane)Mn(CO)3]+ (1) preferentially
We must now ask ourselves why the arene–manganese
tricarbonyl cations 1, 17, and 23 possessing five-, six-, or
seven-membered rings, respectively, exhibit such different
behavior when treated with tert-BuOK. The trindane (or
indane) system apparently yields a metal hydride that subse-
quently suffers a series of hydrogen eliminations, presum-
ably via agostic interactions with suitably positioned benzylic
hydrogens. The tetralin complex 17 appears to undergo pro-
ton abstraction to generate a nucleophile that can attack its
progenitor, whereas deprotonation of the dibenzosuberane-
complexed cation 23 yielded a stable elimination product.
undergoes nucleophilic attack by the tert-butoxide anion on
a metal carbonyl ligand, whereas in the tetralin and
dibenzosuberane complexes, 17 and 23, deprotonation at a
benzylic site is favored. Steric considerations would suggest
that in 23 the positioning of the metal tripod on the concave
face of the dibenzosuberane ligand seriously hinders the ap-
proach of a relatively bulky tert-butoxide; in contrast, the
Mn(CO)3 moiety in the trindane complex 1 is staggered with
respect to the five-membered rings, and the alkoxide can
readily gain access to a carbonyl ligand. Upon removal of a
6
benzylic proton from [(η -dibenzosuberane)Mn(CO)3]+, the
Evidently, there can be competition between deprotona-
tion at a benzylic site and nucleophilic attack by the
alkoxide at a carbonyl ligand. Moreover, even if a manga-
nese-hydride were to be generated in each case, one must
then consider not only the ease or difficulty of forming an
agostic Mn···H···C linkage, but also the strength of the
manganese-to-ligand binding subsequent to the haptotropic
resulting neutral species 28 is sufficiently flexible to allow
the seven-membered ring to fold away from the metal and so
5
adopt a conventional η -cyclohexadienyl conformation; this
molecular deformation may be more difficult for the
deprotonated tetralene complex 22, which therefore retains
its nucleophilic character and attacks the starting material to
5
yield the “dimeric tetralenyl” η -cyclohexadienyl product 21.
6
shift. Taking the X-ray crystallographic data for (η -
To conclude, the reactions of potassium tert-butoxide with
the arene manganese tricarbonyl cations derived from
trindane, indane, tetralin, or dibenzosuberane yield very dif-
ferent products and pose interesting mechanistic questions.
6
trindane)Mn(CO)2Br (3), [(η -tetralin)Mn(CO)2{P(OMe)3}]+
6
(20), and [(η -dibenzosuberane)Mn(CO)3]+ (23), we note
that the Mn-to-benzyl endo-H distances generally lie in the
range 3.42–3.52 Å, considerably longer than might be antici-
pated for
a manganese···hydrogen agostic interaction
Experimental section
(~1.8 Å) (44). However, manganese-hydrogen agostic inter-
actions have been invoked by Cooper and co-workers (38) to
explain the fluxional behavior of the anthracenyl complex 29
whereby an endo benzylic hydrogen undergoes a 1,4 migra-
tion via the metal center. In that case, the metal-hydrogen
distance in the ground state was determined crystallographi-
General procedures
All reactions were carried out under an atmosphere of dry
nitrogen employing conventional benchtop and glovebag
techniques. Silica gel (particle size 20–45 µm) was em-
ployed for flash column chromatography. Radial chromatog-
© 2008 NRC Canada

240
Can. J. Chem. Vol. 87, 2009
raphy was performed using
a
Chromatotron (7942T,
flask. The system was evacuated, flushed with N2 (three
times), and CH2Cl2 (25 mL) was added. The resulting red
solution was left to stir under N2 for 2 h, after which time
the solvent was removed under reduced pressure. The crude
product was chromatographed on a silica gel column (eluent
hexane/acetone 50:50) affording 3 (0.425 g, 1.092 mmol,
93%). NOTE: trimethylamine N-oxide hydrate (Me3NO·2H2O)
was dehydrated by azeotroping the water from a toluene so-
lution.
Harrison Research, Inc.) with silica-coated plates (TLC
grade 7749 with gypsum binder and fluorescent indicator;
1
thickness: 1, 2, or 4 mm). H, 13C, and 31P NMR data were
acquired on Bruker Avance 500, 300, or 200 MHz spectrom-
eters, and chemical shifts are given relative to residual H or
1
13C solvent signal, or externally referenced relative to 85%
H3PO4 in D2O. IR spectra were recorded on a Bio-Rad FTS-
40 single beam spectrometer using KBr pellets or NaCl win-
dows. In situ IR spectra were recorded on an ASI Applied
Systems ReactIR 1000 with a SiComp probe. Mass spectro-
metric data were obtained on a Finnigan EI/CI mass spec-
trometer system, using direct electron impact and chemical
ionization methods. The positive ion electrospray mass spec-
tra were obtained on a Micromass Quattro LC triple
quadrupole mass spectrometer. Melting and decomposition
points were measured on a Fischer-Johns melting point ap-
paratus and are not corrected. Microanalytical data are from
Guelph Chemical Laboratories (Guelph, Ontario) or from the
Microanalytical Laboratory at University College Dublin.
Reaction of [(␩6-trindane)Mn(CO)3][BF4] with tert-
BuOK and methyl iodide
Analogously to the preparation of 3, [(η -trindane)-
6
Mn(CO)3][BF4] (0.513 g, 1.21 mmol), tert-BuOK (2.65 g,
23.6 mmol), and methyl iodide (1.47 mL, 23.6 mmol) in
THF (25 mL) produced a purple solution that eventually
turned yellow-cream. Work-up was as above, and separation
by rotary chromatography (Chromatotron, eluent hexane/
6
CH2Cl2 20:80) yielded (η -trindane)Mn(CO)2I (4) (0.078 g,
0.18 mmol; 15%). IR (NaCl windows, CDCl3, cm–1) νCO
:
6
6
1
[(η -Trindane)Mn(CO)3][BF4] (1) and [(η -trindane)Fe-
(C5H5)][PF6] (2) were prepared as previously described (2).
Following the literature procedure (47), dibenzosuberane
was obtained in 77% yield by reduction of dibenzosuberone
with iodine and hypophosphorous acid in acetic acid.
1973 (s), 1926 (s). H NMR (500 MHz, CDCl3) δ: 2.80 (m,
12H, benzylic CH2), 2.09 (br, 6H, wingtip CH2). 13C NMR
(125 MHz, CDCl3) δ: 108.8 (aromatic C), 30.1 (benzylic
CH2), 23.7 (wingtip CH2). MS (DEI, m/z (%)): 380 (40, [M –
2CO]+), 253 (10, [M – 2CO – I]+), 198 (100, [C15H18]+).
Anal. calcd. for C17H18MnIO2 (%): C 46.81, H 4.16; found:
C 47.02, H 4.32. A crystal suitable for an X-ray diffraction
study was obtained by slow evaporation of dichloromethane
at room temperature under an atmosphere of nitrogen.
Reaction of [(␩6-trindane)Mn(CO)3][BF4] with tert-
BuOK and allyl bromide
A three-neck round-bottomed flask equipped with a side-
6
arm, condenser, septum, and stir bar was charged with [(η -
Reaction of [(␩6-trindane)Mn(CO)3][BF4] with tert-
trindane)Mn(CO)3][BF4] (1) (0.500 g, 1.18 mmol) and tert-
BuOK (1.33 g, 11.87 mmol) and held under vacuum for 3 h
at 40 °C. A solution of allyl bromide (1.02 mL, 11.8 mmol)
in THF (25 mL) was added via cannula, under N2, and pro-
duced a green solution that was maintained at 40 °C, which
eventually turned brownish-orange. After 20.5 h, the solvent
was removed under reduced pressure and the pinkish-red
residue was dissolved in CH2Cl2, filtered, and extracted with
H2O (3 × 10 mL). The organic layers were combined, dried
with Na2SO4, and filtered, and the solvent was removed by
rotary evaporation. After drying under vacuum, 3 was ob-
tained as a dark red powder (0.077 g, 0.198 mmol; 17%),
mp 128–130 °C (dec). IR (NaCl windows, CDCl3, cm–1)
BuOK and trimethyl phosphite
6
Likewise,
[(η -trindane)Mn(CO)3][BF4]
(0.500
g,
1.18 mmol), tert-BuOK (2.65 g, 23.6 mmol), and P(OMe)3
(2.78 mL, 23.6 mmol) in THF (30 mL) produced a red solu-
tion that eventually turned orange-brown. Workup was as
above, and chromatography on a silica gel column (eluent
5
hexane/CH2Cl2 70:30) yielded two fractions, (η -
C15H15)Mn(CO)3 (7) (0.080 g, 0.240 mmol; 20%), mp 87–
5
90 °C and (η -C15H15)Mn(CO)2P(OMe)3] (8) (0.055 g,
0.130 mmol; 11%), mp 124–126 °C.
1
Data for 7: H NMR (200 MHz, CDCl3) δ: 5.03 (d, 2H,
CH), 4.94 (t, 1H, CH), 2.93 (m, 4H, benzylic CH2), 2.79 (m,
4H, benzylic CH2), 2.13 (m, 4H, wingtip CH2). 13C NMR
(50 MHz, CDCl3) δ: 225.4 (Mn-CO), 139.4 (C6/C9 or
C7/C8, C=C), 135.2 (C6/C9 or C7/C8, C=C), 101.1
(C4/C5), 87.4 (C2, CH), 69.7 (C1/C3, CH), 32.1 (benzylic
CH2), 25.5 (wingtip CH2), 32.1 (benzylic CH2). Anal. calcd.
for C18H15MnO3 (%): C 64.68, H 4.52; found: C 65.01, H
4.67. After numerous attempts, yellow crystals were grown
from chloroform at 0 °C under an atmosphere of nitrogen,
but were not of ideal quality. Nevertheless, an X-ray diffrac-
tion study was undertaken and the molecular structure was
determined.
ν
CO: 1971(s), 1927 (s). 1H NMR (200 MHz, CD2Cl2) δ: 2.76
(br, 12H, benzylic CH2), 2.04 (br, 6H, wingtip CH2). 13C
NMR (50 MHz, CD2Cl2) δ: 110.3 (aromatic C), 30.1
(benzylic CH2), 24.1 (wingtip CH2). Mass spectrum (MS)
(DEI, m/z (%)): 198 (100, [C15H18]+), 115 (5, [C9H7]+). (As
with (C6Me6)Mn(CO)2Br, no parent ion was detectable; only
peaks attributable to the ligand were observed.) Anal. calcd.
for C17H18MnBrO2 (%): C 52.47, H 4.66; found: C 52.04, H
4.92. A crystal suitable for an X-ray diffraction study was
obtained by slow evaporation of dichloromethane at room
temperature under an atmosphere of nitrogen.
Data for 8: IR (NaCl windows, CDCl3, cm–1) νCO: 1944
Alternative route to (␩6-trindane)Mn(CO)2Br (3)
1
(s), 1876 (s). H NMR (500 MHz, CDCl3) δ: 4.84 (m, 3H,
3
The second synthesis of 3 is based on the previously re-
CH), 3.38 (d, JH-P = 11.7 Hz, 9H, OCH3), 3.04 (m, 2H,
6
6
ported preparation of (η -C6Me6)Mn(CO)2Br (12). [(η -
Trindane)Mn(CO)3][BF4] (0.501 g, 1.18 mmol), Me3NO
(0.107 g, 1.29 mmol), and (n-Bu)4NBr (0.566 g,
1.433 mmol) were combined in a two-neck round-bottomed
benzylic CH2), 2.92 (m, 2H, benzylic CH2), 2.84 (m, 2H,
benzylic CH2), 2.75 (m, 2H, benzylic CH2), 2.16 (m, 4H,
wingtip CH2). 13C NMR (125 MHz, CDCl3) δ: 137.9 (C6/C9
or C7/C8, C=C), 135.8 (C6/C9 or C7/C8, C=C), 100.9
© 2008 NRC Canada

Reginato et al.
241
(C4/C5), 87.0 (C2, CH), 68.7 (C1/C3, CH), 51.1 (OCH3),
32.2 (benzylic CH2), 31.8 (benzylic CH2), 24.6 (wingtip
CH2). 31P NMR (81.04 MHz, CDCl3) δ: 211.6 (s). MS (DEI,
m/z (%)): 430 (11, [M]+), 374 (100, [M – 2CO]+), 281(21,
(35 mL) produced a reddish-orange solution. Work-up
5
yielded (η -indenyl)Mn(CO)2PPh3 (0.017 g, 0.0348 mmol,
11%). IR (NaCl windows, CDCl3, cm–1) νCO: 1934 (s), 1866
(s), lit. (18); (nujol) υCO: 1931(s), 1863 (s). 1H NMR
(300 MHz, CD2Cl2) δ: 7.09 (m, 19H, aromatic C and
CH=CH), 4.65 (m, 3H, Cp). 13C NMR (75 MHz, CDCl3) δ:
232.8 (Mn-CO), 133.7, 133.5, 130.1, 128.6, 128.5, 126.1,
125.9, 90.1 (Cp), 72.9 (Cp). 31P NMR (81.05 MHz, CD2Cl2)
δ: 92.4 (s). MS (DEI, m/z (%)): 488 (6, [M]+), 432 (92, [M –
2CO]+), 377 (1, [M – 2CO – Mn]+), 115 (100, [C9H7]+).
+
[M – 2CO – 3(OMe)]+), 251 (51, [M – 2CO – P(OMe)3 ),
195 (44, [(C15H15)]+). Anal. calcd. for C20H24MnO5P (%): C
55.82, H 5.62; found: C 55.45, H 5.96. A yellow crystal
suitable for an X-ray diffraction study was grown from chlo-
roform at 0 °C under an atmosphere of nitrogen.
Reaction of [(␩6-trindane)Mn(CO)3][BF4] with tert-
BuOK and triphenylphosphine
Reaction of [(␩6-indane)Mn(CO)3][BF4] with tert-BuOK
6
and trimethyl phosphite
As for the reaction with triphenylphosphine, [(η -
indane)Mn(CO)3][BF4] (0.500 g, 1.457 mmol), t-BuOK
Analogously to the preparation of 8, [(η -trin-
6
dane)Mn(CO)3][BF4] (0.500 g, 1.182 mmol), tert-BuOK
(2.65 g, 23.6 mmol), THF (30 mL), and PPh3 (619 g,
23.6 mmol) yielded three fractions after separation on a
(3.27 g, 29.0 mmol), and P(OMe)3 (619 g, 23.6 mmol) in
5
5
Chromatron (eluent hexane/CH2Cl2 90:10): PPh3, (η -
THF (30 mL) yielded (η -indenyl)Mn(CO)2[P(OMe)3]
5
C15H15)Mn(CO)3 (7), and (η -C15H15)Mn(CO)2[PPh3] (9)
(0.001 g, 2.857 mmol, 2%). IR (NaCl windows, CDCl3, cm–1)
1
(0.060g, 0.1056 mmol; 9%), mp 179–180 °C (dec). IR (NaCl
ν
CO: 1950 (s), 1881 (s). H NMR (200 MHz, CDCl3) δ: 7.40
windows, CDCl3, cm–1) νCO: 1929 (s), 1862 (s). H NMR
(m, 2H, CH=CH), 7.02 (m, 2H, CH=CH), 4.97 (m, 2H, CH),
1
3
(500 MHz, CDCl3) δ: 7.31 (m, 15H, aromatic CH), 4.60 (d,
2H, CH), 4.47 (m, 1H, CH), 2.51 (m, 8H, benzylic CH2),
2.08 (m, 4H, wingtip CH2). 13C NMR (125 MHz, CDCl3) δ:
138.1, 137.8, 136.1, 133.1 (JC-P = 10.4 Hz), 129.5, 128.1
(JC-P = 9.3 Hz), 100.7 (C4/C5), 89.0 (C2, CH), 70.7 (C1/C3,
CH), 32.3 (benzylic CH2), 32.0 (benzylic CH2), 24.6
(wingtip CH2). 31P NMR (81.04 MHz, CDCl3) δ: 94.3. MS
(DEI, m/z (%)): 569 (100, [M + H]+), 512 (58, [M – 2CO]+),
195 (62, [C15H15]+); (CI, NH3, m/z (%)): 569 (100, [M +
H]+), 512 (58, [M – 2CO]+), 195 (63, [C15H15]+). Anal.
calcd. for C35H30MnO2P (%): C 73.94, H 5.28; found: C
74.18, H 5.49.
4.83 (m, 1H, CH), 3.42 (d, 9H, JC-P = 11.7 Hz, OCH3). 31P
NMR (81.05 MHz, CD2Cl2) δ: 211.4 (s). MS (DEI, m/z
(%)): 350 (12, [M]+), 322 (5, [M – CO]+), 294 (100, [M –
2CO]+), 170 (29, [C9H7Mn]+), 115 (41, [C9H7]+).
Preparation of [(␩6-trindane)Mn(CO){P(OMe)3}2][BF4] (15)
6
[(η -Trindane)Mn(CO)3][BF4] (0.463 g, 1.095 mmol) and
Me3NO (0.173 g, 2.307 mmol) were stirred in CH2Cl2
(55 mL) under N2. To the yellow solution was added
P(OMe)3 (0.20 mL, 1.696 mmol) whereupon the solution
turned red instantaneously. The solution was allowed to stir
under N2 for 6 h at room temperature, the solvent was re-
moved under pressure, and the crude material was purified
by chromatographic separation on a silica gel column
(eluent CH2Cl2/acetone 90:10) giving rise to two fractions.
The first fraction was identified as trindane and the second
was 15 (0.071 g, 0.115 mmol, 11%). IR (NaCl windows,
CDCl3, cm–1) υCO: 1911 (s). 1H NMR (300 MHz, CD2Cl2) δ:
Preparation of [(␩6-indane)Mn(CO)3][BF4] (10)
A mixture of Mn(CO)5Br (1.08 g, 4.029 mmol) and
AgBF4 (0.78 g, 4.029 mmol) in dry CH2Cl2 (40 mL) was
heated at reflux for 3 h under nitrogen and then cooled to
room temperature. To the reaction mixture, a solution of
indane (0.493 mL, 4.029 mmol) in dry CH2Cl2 (10 mL) was
added, and the reaction mixture was heated at reflux for
18 h. After cooling and filtration, the filtrate was passed
through Celite and concentrated to approximately one-third
its volume under reduced pressure, and excess hexane
(80 mL) was added. The resulting yellow solid was filtered
and dried in vacuo to furnish 10 (0.658 g, 1.918 mmol,
50%). IR (NaCl windows, CDCl3, cm–1) υCO: 2065 (s), 2008
3
3.71 (t, 18H, JP-H = 5.0 Hz, P(OMe)3), 2.74 (m, 12H,
benzylic CH2), 2.08 (m, 6H, wingtip CH2). 13C NMR
(75 MHz, CD2Cl2) δ: 111.7 (aromatic C), 54.5 (OCH3), 30.4
(benzylic CH2), 23.2 (wingtip CH2). 31P NMR (121.51 MHz,
CD2Cl2) δ: 185.5 (s). MS (positive ESI, m/z (%)): 529 (100,
[M+]), 405 (3, [M – P(OMe)3]+), 377 (8, [M – P(OMe)3 –
CO]+). Anal. calcd. for C22H36MnO7P2 (%): C 42.88, H
5.89; found: C 42.69, H 5.86. A sample suitable for single-
crystal X-ray diffraction was obtained by crystallization
from dichloromethane by slow evaporation under nitrogen at
room temperature.
1
(s). H NMR (200 MHz, CD2Cl2) δ: 6.53 (m, 4H, aromatic),
3.03 (m, 4H, benzylic CH2), 2.44 (m, 1H, wingtip CH2),
2.10 (m, 1H, wingtip CH2). 13C NMR (50 MHz, CD2Cl2) δ:
227.2 (Mn-CO), 99.3 (aromatic C), 98.2 (aromatic C), 32.2
(benzylic CH2), 23.7 (wingtip CH2). MS (positive ESI, m/z
(%)): 258 (M + 1, 24% of [M]+), 257 (100, [M]+), 229 (5.3,
[M – CO]+), 201 (2.7, [M – 2CO]+), 173 (1.9, [M – 3CO]+).
Anal. calcd. for C12H10O3MnBF4 (%): C 41.90, H 2.93;
found: C 41.69, H 2.76.
Preparation of [(␩6-trindane)Re(CO)3][PF6] (16)
In a 100 mL round-bottomed flask, BrRe(CO)5 (0.944 g,
2.324 mmol), trindane (0.765 g, 3.864 mmol), AlCl3
(1.630 g, 12.22 mmol), and petroleum ether (55 mL) were
heated at reflux under nitrogen for 16.5 h. The solution was
cooled in an ice-bath, followed by addition of an ice-water
slush (25 mL). The petroleum ether layer was decanted, and
the remaining water layer was washed with cold diethyl
ether followed by the addition of excess NH4PF6 in water
(5 mL). The resultant white precipitate (0.028 g,
0.0456 mmol, 2%) was filtered and washed with cold water
Reaction of [(␩6-indane)Mn(CO)3][BF4] with tert-BuOK
and triphenylphosphine
Following the procedure for 3, [(η -indane)Mn-
(CO)3][BF4] (0.106 g, 0.3089 mmol), t-BuOK (0.693 g,
6
6.178 mmol), and PPh3 (1.620 g, 6.178 mmol) in THF
© 2008 NRC Canada

242
Can. J. Chem. Vol. 87, 2009
and methanol. IR (KBr pellet, cm–1) υCO: 2052 (s), 1956 (s).
IR (NaCl windows, CDCl3, cm–1) υCO: 2058 (s), 1966 (s).
1H NMR (500 MHz, CD2Cl2) δ: 3.38 (m, 6H, benzylic
CH2), 2.95 (m, 6H, benzylic CH2), 2.44 (m, 3H, wingtip
CH2), 1.91 (m, 3H, wingtip CH2). 13C NMR (125.773 MHz,
CD2Cl2) δ: 185.7 (Mn-CO), 118.7 (aromatic C), 30.4
(benzylic CH2), 24.7 (wingtip CH2). MS (positive ESI, m/z
(%)): 469 (100, [M]+).
21.6. MS (positive ESI, m/z (%)): 271 (100, [M]+), 243 (8,
[M – CO]+), 214 (23, [M – 2CO]+), 187 (7, [M – 3CO]+).
Reaction of [(␩6-tetralin)Mn(CO)3][PF6] with trimethyl
phosphite
A 100 mL Schlenk flask equipped with a side arm and stir
6
bar was charged with [(η -tetralin)Mn(CO)3][PF6] (17)
(0.902 g, 2.168 mmol) and evacuated and purged with N2
three times. A solution of THF (30 mL) containing P(OMe)3
(5.11 mL, 43.4 mmol) was added dropwise under N2, the so-
lution was yellow in colour. The solution was stirred for
20 h under N2 and the solvent was then removed under re-
duced pressure. The residue was dissolved in CH2Cl2 and
hexanes, a precipitate formed, and it was filtered. The re-
maining solution was chromatographed on a silica gel col-
umn (eluent 100% hexane) affording 20, a yellow compound
(0.658 g, 1.285 mmol, 59%), mp 86–88 °C. IR (NaCl win-
dows, CDCl3, cm–1) υCO: 2008 (s), 1961 (s). 1H NMR
(200 MHz, CDCl3) δ: 5.94 (m, 4H, aromatic CH), 3.70 (t,
Attempted synthesis of [(␩6-(CH3)12C15H6)FeCp][PF6]
6
[(η -C15H18)FeCp][PF6] (2) (0.124 g, 0.267 mmol) and
potassium tert-butoxide (7.20 g, 64 mmol) were stirred to-
gether under vacuum for 3 h, and a solution of methyl iodide
(3.98 mL, 64 mmol) in freshly distilled THF (60 mL) was
introduced by syringe. The solution became deep red in col-
our and continued to change colour (dark purple to mauve to
pink) until the solution remained yellowish-cream in colour.
After 48 h under nitrogen at 40 °C in the dark, the product
was worked up as before, and chromatographed on an alu-
mina neutral column (eluent hexane/acetone 90:10) to afford
3
9H, JH-P = 11.6 Hz, OCH3), 2.73 (m, 4H, CH2), 1.79 (m,
1
three orange products. The H and 13C NMR spectra of each
2
4H, CH2). 13C NMR (50 MHz, CDCl3) δ: 220.3 (d, JC-P
=
fraction still indicated a mixture of compounds. Similarly
positive ESI mass spectrometric data exhibited signals at m/z
459, 473, and 487 corresponding to the incorporation of 10,
11, and 12 methyls, respectively. Two samples suitable for
structural determination by single-crystal X-ray diffraction
were obtained by recrystallization from hexanes/acetone
mixture; however, the structure has not been satisfactorily
refined as a result of a disorder in the trindane fragment.
43.2 Hz, Mn-CO), 113.9 (C1/C6), 97.8 (C2/C5 or C3/C4),
96.7 (C2/C5 or C3/C4), 54.1 (d, 2JC-P = 7.3 Hz, OCH3), 27.5
(C7/C10), 21.1 (C7/C10). 31P NMR (81.04 MHz, CDCl3) δ:
182.1 (s, P(OMe)3), –167.4 (septet, PF6). MS (positive ESI,
m/z (%)): 367 (100, [M+]), 311 (19, [M – 2CO]+). Anal.
calcd. for C15H21MnO5P2F6 (%): C 35.17, H 4.13; found: C
35.51, H 3.96. A sample suitable for single-crystal X-ray
diffraction was obtained by crystallization from chloroform
by slow evaporation under an atmosphere of nitrogen at
room temperature.
Attempted synthesis of [(␩6-(CH2CHCH2)12C15H6)FeCp][PF6]
6
Similarly, [(η -C15H18)FeCp][PF6], 2, (0.233 g,
Reaction of [(␩6-tetralin)Mn(CO)3][PF6] with tert-BuOK
0.502 mmol), potassium tert-butoxide (13.5 g, 120 mmol),
and allyl bromide (10.43 mL, 120 mmol) in THF (60 mL)
became deep red in colour and continued to change colour
(pink to violet to mauve) until the solution remained yellowish-
cream in colour. After work-up, the crude product was chro-
matographed on an alumina neutral column (eluent hexane)
affording two yellow products. The 1H and 13C NMR spectra
of each fraction still indicated a mixture of compounds. Sim-
ilarly positive ESI mass spectrometric data exhibited signals
consistent with the incorporation of 12 allyl groups at m/z
799, followed by consecutive losses of multiples of 40 to a
A round-bottomed flask equipped with a side arm and stir
6
bar was charged with [(η -tetralin)Mn(CO)3][PF6] (17)
(0.952 g, 2.288 mmol) and t-BuOK (5.14 g, 45.8 mmol) and
evacuated and purged with N2 three times. This was fol-
lowed by the addition of THF (30 mL) under N2, which pro-
duced a dark orange-brown solution, which was stirred for
6 h under N2. The solvent was removed under reduced pres-
sure and the residue was dissolved in methylene chloride.
Hexanes were added to the solution and, after filtration, the
solvent was removed by rotary evaporation yielding a yel-
low-orange oil that was separated on a Chromatotron (eluent
hexane with gradual addition of CH2Cl2) furnishing 21
(0.114 g, 0.284 mmol, 12%). IR (NaCl windows, neat, cm–1)
6
m/z of 319 (which corresponds to [(η -C15H18)FeCp]+).
Preparation of [(␩6-tetralin)Mn(CO)3][PF6] (17)
υ
CO: 2007 (s), 1927 (s). MS (CI, NH3, m/z (%)): 403 (100,
As described in the literature (25), Mn(CO)5Br (1.97 g,
7.16 mmol), AlCl3 (1.91 g, 14.3 mmol), tetralin (1.88 mL,
0.0138 mmol), and cyclohexane (50 mL) were heated at re-
flux for 5 h under N2. The solution was cooled, followed by
the addition of ice-cold H2O (40 mL). To the aqueous layer,
NH4PF6 (2.21 g, 0.0138 mmol) was added, yielding a yellow
precipitate that was filtered and dried under vacuum. The
product (2.383 g, 5.73 mmol, 80%) was recrystallized from
a mixture of acetone and diethyl ether. Complete spectro-
scopic assignment of this compound had not been published
[M + 1]+), 271 (57, [M – C10H11]+), 187 (3, M – C10H11
3CO]+, 131 (8, [C10H11]+).
–
Preparation of [(␩6-dibenzosuberane)Mn(CO)3][BF4]
(23)
A mixture of Mn(CO)5Br (1.90 g, 6.92 mmol) and AgBF4
(1.48 g, 7.61 mmol) in dry CH2Cl2 (50 mL) was heated at
reflux for 3 h under nitrogen and then cooled to room
temperature. To the reaction was added a solution of
dibenzosuberane (1.78 g, 9.20 mmol) in dry CH2Cl2
(15 mL), and the mixture was heated at reflux overnight. Af-
ter cooling and filtration, the filtrate was passed through
Celite and concentrated to approximately one-third its vol-
ume under reduced pressure, and excess hexane (100 mL)
prior to this study. IR (NaCl windows, CDCl3, cm–1) υCO
:
2068 (s), 2025 (s), 2003 (s), lit. (25) (NaCl) υCO: 2056 (s),
1
2016 (s). H NMR (200 MHz, acetone-d6) δ: 6.84 (s, 4H,
CH), 3.13 (m, 4H, CH2), 2.30 (m, 4H, CH2). 13C NMR
(50 MHz, acetone-d6) δ: 216.9, 119.5, 101.9, 99.8, 28.2,
© 2008 NRC Canada

Reginato et al.
243
Table 1. Crystallographic collection and refinement parameters for 3, 4, 7, and 8.
Compound
3
4
7
8
Empirical formula
C17H18O2BrMn
C17H18O2IMn
C18H15O3Mn
C20H24O5PMn
Formula weight
Temperature (K)
Wavelength (Å)
Crystal system
Space group
389.16
299(2)
0.71073
Monoclinic
P21/c
436.15
299(2)
0.71073
Orthorhombic
Pbca
334.24
173(2)
0.71073
Monoclinic
C2/c
430.30
299(2)
0.71073
Monoclinic
P21/c
a (Å)
b (Å)
c (Å)
9.8049(13)
8.8852(13)
18.682(3)
90
94.825(3)
90
1621.8(4)
4
1.594
14.408(3)
15.080(2)
15.264(3)
90
90
90
3316.4(10)
8
1.747
16.567(18)
9.919(14)
18.524(26)
90
98.09(5)
90
3013.7(68)
8
1.473
9.7325(17)
22.355(4)
9.6052(17)
90
106.484(5)
90
2003.9(6)
4
1.426
α (°)
β (°)
γ (°)
Volume (Å3)
Z
Dcalcd. (Mg/m3)
Absorption coefficient (mm–1)
F(000)
3.278
784
2.659
1712
0.885
1376
0.766
896
Crystal size (mm)
Theta range for data collection (°)
Index ranges
0.06 × 0.08 × 0.24
2.08–23.25
–10 ≥ h ≥ 10
–9 ≥ k ≥ 9
–20 ≥ l ≥ 20
10 041
0.14 × 0.28 × 0.33
2.37–24.99
–16 ≥ h ≥ 17
–17 ≥ k ≥ 17
–18 ≥ l ≥ 18
23 135
0.04 × 0.22 × 0.42
2.40–24.99
–21 ≥ h ≥ 20
–7 ≥ k ≥ 11
–21 ≥ l ≥ 16
2 507
0.08 × 0.33 × 0.35
1.82–27.50
–12 ≥ h ≥ 12
–28 ≥ k ≥ 26
–12 ≥ l ≥ 11
17 829
Reflections collected
Independent reflections
2318
2919
1717
4584
[R(int) = 0.0907]
SADABS
Full-matrix least-
squares on F2
2318/0/191
1.075
[R(int) = 0.0323]
SADABS
Full-matrix least-
squares on F2
2919/0/192
1.053
[R(int) = 0.2486]
SADABS
Full-matrix least-
squares on F2
1679/0/199
1.080
[R(int) = 0.0300]
SADABS
Full–matrix least–
squares on F2
4584/0/245
Absorption correction
Refinement method
Data/restraints/parameters
Goodness-of-fit on F2
1.030
Final R indices [I > 2σ(I)]
R1 = 0.0560,
wR2 = 0.1326
R1 = 0.1070,
wR2 = 0.1582
0.0000(5)
R1 = 0.0412,
wR2 = 0.1159
R1 = 0.0490,
wR2 = 0.1237
R1 = 0.1455,
wR2 = 0.3683
R1 = 0.1943,
wR2 = 0.4620
0.0000(9)
R1 = 0.0350,
wR2 = 0.0876
R1 = 0.0528,
wR2 = 0.0947
R indices (all data)
Extinction coefficient
Absolute structure parameter
Largest diff. peak and hole (e·Å–3)
0.464 and –0.436
0.756 and –0.1.292
1.304 and –1.241
0.252 and –0.214
was added. The resulting yellow solid was filtered and dried
single-crystal X-ray diffraction was obtained by crystalliza-
tion from acetone at room temperature.
under vacuum furnishing 23 (0.301 g, 0.718 mmol, 10%),
mp 218–220 °C. IR (NaCl windows, CDCl3, cm–1) υCO
:
1
Reaction of [(␩6-dibenzosuberane)Mn(CO)3][BF4] with
tert-BuOK
2065 (s), 2014 (s). H NMR (500 MHz, acetone-d6) δ: 7.38
(d, 1H, J = 7.3 Hz, H7/H10), 7.31 (m, 2H, H8, H9), 7.25 (t,
1H, J = 7.1, H7/H10), 7.13 (d, 1H, J = 6.6 Hz, H1/H4), 6.91
(t, 1H, J = 6.3 Hz, H2/H3), 6.58 (t, 2H, J = 6.3 Hz, H1/H3
or H2/H4), 4.48 (d, 1H, J = 15.5 Hz, H11a/H11b), 4.31 (d,
1H, J = 15.5 Hz, H11a/H11b), 3.44 (m, 3H, H6a/H6b,
H5a/H5b), 3.27 (m, 1H, H6a/H6b, H5a/H5b). 13C NMR
(125 MHz, acetone-d6) δ: 216.4 (Mn-CO), 139.6 (C12/C15),
138.6 (C12/C15), 130.2 (C8/C9), 129.8 (C7/C10), 129.4
(C8/C9), 128.0 (C7/C10), 123.7 (C14/C15), 118.6
(C14/C15), 105.5 (C1/C4), 103.1 (C2/C3), 100.6 (C2/C3),
97.3 (C2/C3 or C2/C4), 38.4 (C11), 32.1 (C5/C6). MS (posi-
tive ESI, m/z (%)): 333 (100, [M+]), 277 (6.15, [M –
2CO]+), 249 (17.75, [M – 3CO]+). Anal. calcd. for
C18H14MnO3BF4 (%): C 51.47, H 3.36; found: C 51.48, H
3.51. A sample suitable for structural determination by
A round-bottomed flask equipped with a side arm and stir
6
bar was charged with [(η -dibenzosuberane)Mn(CO)3][BF4]
(23) (0.377 g, 0.90 mmol) and t-BuOK (2.02 g, 18.0 mmol)
and evacuated and purged with N2 three times. This was fol-
lowed by the addition of THF (25 mL) under N2, which pro-
duced a dark red-brown-orange solution, which was stirred
for 4 h under N2. The solvent was removed under reduced
pressure and the residue was dissolved in ether. Water
(40 mL) was added to the ether solution and extracted with
ether (2 × 10 mL). The organic layers were combined, dried
with MgSO4, and filtered. The solvent was removed by ro-
tary evaporation yielding a red-orange material that was sep-
arated on a Chromatotron (eluent hexane with gradual
addition of CH2Cl2) furnishing 28, as an orange powder
© 2008 NRC Canada

244
Can. J. Chem. Vol. 87, 2009
Table 2. Crystallographic collection and refinement parameters for 15, 20, 23, and 28.
Compound
15
20
23
28
Empirical formula
C22H36O7P2MnBF4
C15H21O5P2F6Mn
C18H14O3MnBF4
C18H13O3Mn
Formula weight
Temperature (K)
Wavelength (Å)
Crystal system
Space group
616.20
173(2)
0.71073
Triclinic
P1
512.20
173(2)
0.71073
Orthorhombic
Pnma
420.04
173(2)
0.71073
Monoclinic
P21/n
332.22
173(2)
0.71073
Monoclinic
C2
a (Å)
b (Å)
c (Å)
9.3299(19)
11.082(2)
12.969(3)
97.600(3)
94.229(3)
91.929(3)
1324.2(5)
2
15.694(5)
10.991(4)
11.735(4)
90
90
90
2024.4(11)
4
1.681
7.733(2)
7.774(2)
28.795(7)
90
96.660(4)
90
1719.4(7)
4
1.623
25.577(14)
6.255(3)
9.362(5)
90
107.230(8)
90
1430.5(14)
4
1.543
α (°)
β (°)
γ (°)
Volume (Å3)
Z
Dcalcd. (Mg/m3)
1.545
Absorption coefficient (mm–1)
F(000)
0.688
640
0.889
1040
0.825
848
0.932
680
Crystal size (mm)
Theta range for data collection (°)
Index ranges
0.18 × 0.42 × 0.44
1.59 to 27.52
–12 ≥ h ≥ 11
–14 ≥ k ≥ 14
–16 ≥ l ≥ 15
11 886
0.32 × 0.45 × 0.70
2.17 to 27.69
–20 ≥ h ≥ 18
–14 ≥ k ≥ 14
–14 ≥ l ≥ 15
16 907
0.12 × 0.28 × 0.42
1.42 to 27.50
–9 ≥ h ≥ 10
–9 ≥ k ≥ 10
–37 ≥ l ≥ 37
14 780
0.03 × 0.05 × 0.50
1.67 to 27.51
–32 ≥ h ≥32
–8 ≥ k ≥ 8
–12 ≥ l ≥ 11
6 352
Reflections collected
Independent reflections
5981
2455
3936 |
2802
[R(int) = 0.0259]
SADABS
Full-matrix least-
squares on F2
5981/0/334
1.047
[R(int) = 0.0419]
SADABS
Full-matrix least-
squares on F2
2452/0/222
1.164
[R(int) = 0.0290]
SADABS
Full-matrix least-
squares on F2
3935/0/240
1.051
[R(int) = 0.0604]
SADABS
Full-matrix least-
squares on F2
2802/0/200
1.034
Absorption correction
Refinement method
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [I > 2σ(I)]
R1 = 0.0368,
wR2 = 0.0938
R1 = 0.0455,
wR2 = 0.0988
R1 = 0.0343,
wR2 = 0.0882
R1 = 0.0469,
wR2 = 0.0991
0.0000(3)
R1 = 0.0481,
wR2 = 0.1208
R1 = 0.0588,
wR2 = 0.1272
0.0001(7)
R1 = 0.0520,
wR2 = 0.0925
R1 = 0.0894,
wR2 = 0.1044
0.0000(7)
R indices (all data)
Extinction coefficient
Absolute structure parameter
Largest diff. peak and hole (e·Å–3)
0.50(3)
0.412 and –0.372
0.423 and –0.358
0.538 and –0.712
1.033 and –1.215
(0.131 g, 0.395 mmol, 44%). IR (NaCl windows,
able for structural determination by single-crystal X-ray dif-
fraction studies was grown from dichloromethane by slow
evaporation under an atmosphere of nitrogen at room tem-
perature.
1
CDCl3, cm–1) υCO: 2022 (s), 1950 (s). H NMR (500 MHz,
CD2Cl2) δ: 7.05 (m, 4H, aromatic CH), 5.61 (t, 1H, J =
5.1 Hz, CH), 5.18 (t, 1H, J = 6.3 Hz, CH), 5.09 (d, 1H, J =
5.3 Hz, CH), 4.41 (d, 1H, J = 7.3 Hz, CH), 4.10 (s, 1H, CH),
3.23 (m, 2H, CH2), 2.47 (m, 2H, CH2). 13C NMR (125 MHz,
CD2Cl2) δ: 222.4 (Mn-CO), 138.7, 133.5, 130.1, 129.5,
126.6, 125.3, 106.7, 100.3, 98.6, 74.8, 74.6, 60.8, 38.0, 36.4,
32.9. MS (DEI, m/z (%)): 332 (2, [M]+), 276 (3.2, [M –
2CO]+), 248 (3.2, [M – 3CO]+), 193 (100, [C15H13]+). Anal.
calcd. for C18H13MnO3 (%): C 65.06, H 3.92; found: C
65.45, H 3.96. A rod-shaped, orange crystalline sample suit-
X-ray crystal structure determinations3
X-ray crystallographic data (see Tables 1 and 2) were col-
lected from single crystal samples, each of which was
mounted on a glass fibre. Data were collected using a P4
Bruker diffractometer, equipped with a Bruker SMART 1K
charge coupled device (CCD) area detector, using the pro-
gram SMART (48), and a rotating anode, using graphite-
3 Supplementary data for this article are available on the journal Web site (canjchem.nrc.ca) or may be purchased from the Depository of Un-
published Data, Document Delivery, CISTI, National Research Council Canada, Ottawa, ON K1A 0R6, Canada. DUD 3811. For more in-
formation on obtaining material refer to cisti-icist.nrc-cnrc.gc.ca/cms/unpub_e.shtml. CCDC 681235 (3), 681234 (4), 681228 (7), 681233
(8), 681232 (15), 681231 (20), 681230 (23), and 681229 (28) contain the crystallographic data for this manuscript. These data can be ob-
tained, free of charge, via www.ccdc.cam.ac.uk/conts/retrieving.html (Or from the Cambridge Crystallographic Data Centre, 12 Union
Road, Cambridge CB2 1EZ, UK; fax +44 1223 336033; or deposit@ccdc.cam.ac.uk).
© 2008 NRC Canada

Reginato et al.
245
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Acknowledgements
Financial support from the Natural Sciences and Engi-
neering Research Council of Canada (NSERC), from Sci-
ence Foundation Ireland, and from University College
Dublin, is gratefully acknowledged. Mass spectra were ac-
quired courtesy of Dr. Kirk Green of the McMaster Regional
Mass Spectrometry Facility. We also thank Dr. James F.
Britten for X-ray crystallographic advice.
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