Portability of the RNNMo(3+) core - Application to the synthesis of dinitrogen-derived trialkoxymolybdenum organodiazenido complexes

Article abstract of DOI:10.1139/v05-025

An alcoholysis strategy has been employed in the synthesis of new oligo- or polymeric trialkoxymolybdenum diazenido complexes [R¹NNMo(O-1-Ad) ₃]_x (R¹ = Me or C(O)OMe) as well as their mononuclear THF solvates R<

Full text of DOI:10.1139/v05-025

302
Portability of the RNNMo(3+) core — Application to
the synthesis of dinitrogen-derived
trialkoxymolybdenum organodiazenido complexes1
John-Paul F. Cherry, Paula L. Diaconescu, and Christopher C. Cummins
Abstract: An alcoholysis strategy has been employed in the synthesis of new oligo- or polymeric trialkoxymolybdenum
diazenido complexes [R1NNMo(O-1-Ad)3]x (R1 = Me or C(O)OMe) as well as their mononuclear THF solvates
R1NNMo(O-1-Ad)3(THF). Dinitrogen-derived diazenido precursor complexes R1NNMo(N[R]Ar)3 (R = i-Pr, Ar = 3,5-
C6H3Me2) react smoothly with 3 equiv. 1-adamantanol to liberate 3 equiv. HN(R)Ar without disruption of the diazeni-
domolybdenum(3+) core. X-ray structural investigations were carried out for diazenido complex MeNNMo(O-1-
Ad)3(THF) and for the corresponding cationic dimethyldiazenido complex [Me2NNMo(O-1-Ad)3(THF)]+, obtained as its
triflate salt. The latter cation was found upon cobaltocene reduction to undergo N—N bond cleavage, producing nitride
NMo(O-1-Ad)3 (synthesized independently) and dimethylamine.
Key words: molybdenum, dinitrogen, bond cleavage, hydrazido, diazenido.
Résumé : On a utilisé une stratégie d’alcoolyse dans la synthèse de nouveaux complexes oligo- et polymériques du
diazénido trialkoxymolybdène [R1NNMo(O-1-Ad)3]x (R1 = Me ou C(O)OMe) et celle de leurs complexes monomolécu-
laires monosolvatés par le THF R1NNMo(O-1-Ad)3(THF). Les complexes précurseurs diazénido dérivés du diazote
R1NNMo(N[R]Ar)3 (R = i-Pr, Ar = 3,5-C6H3Me2) réagissent sans problème avec trois équivalents d’adamant-1-ol pour
libérer trois équivalents de HN(R)Ar sans disruption du noyau diazénidomolybdène(3+). On a examiné les structures du
complexe diazénido MeNNMo(O-1-Ad)3(THF) et du complexe diméthyldiazénido cationique correspondant
[Me2NNMo(O-1-Ad)3(THF)]+ isolé sous la forme de triflate. On a trouvé que la réduction de ce dernier cation par le
cobaltocène conduit à un clivage de la liaison N—N qui conduit à la formation du nitrure NMo(O-1-Ad)3 (qui a été
synthétisé par une voie indépendante) et de la diméthylamine.
Mots clés : molybdène, diazote, clivage d’une liaison, hydrazido, diazénido.
[Traduit par la Rédaction] Cherry et al. 307
Introduction
ported in a system that produces 15NMo(O-t-Bu)3 from 15N2
(19).
Amide (NR21–) ligands (1) and tripodal variants incorpo-
rating them have become established supporting ligands for
the dinitrogen chemistry of metals from groups 4, 5, and 6
(2–16). In contrast, while early metal alkoxides and (or)
aryloxides are abundant and their chemistry is well-
established (17), the combination of alkoxide supporting lig-
ands and dinitrogen activation–functionalization remains rare.
A prime example of dinitrogen binding, activation, and
cleavage to nitride by an early metal aryloxy system is pro-
vided by the niobium-calix[4]arene system reported by
Floriani and co-workers (18). Furthermore, N2 splitting in
combination with intermetal N-atom transfer has been re-
Since a common mode of reactivity for coordinated dini-
trogen is that involving treatment with simple electrophiles
(e.g., H+, Me+ synthons) and conversion to diazenido
(NNH1– or NNMe1–) units (20–24), and since such conver-
sions are essentially absent from the known chemistry of
early-metal alkoxides, we sought an alternative synthetic entry
to trialkoxymolybdenum(IV) diazenido systems. Dinitrogen-
derived diazenido, hydrazido, and related ligands have inter-
ested theoreticians for at least a quarter century (25).
We have shown recently that certain Mo-ligand multiply
bonded functional groups are “portable” in the sense that
they can be retained while exchanging all the supporting lig-
ands. Accordingly, the monomeric terminal phosphide (P3–)
complex PMo(O-1-MeCy)3 was synthesized by treatment of
PMo(N[i-Pr]Ar)3 with 3 equiv. of 1-methyl cyclohexanol
(26). In addition, a variety of Schrock-type alkyne metathe-
sis catalysts R1CMo(OR2)3 could be synthesized by an anal-
ogous alcoholysis protocol, involving treatment of precursor
R1CMo(N[i-Pr]Ar)3 with 3 equiv. of the desired alcohol or
phenol, R2OH (27, 28). The latter two examples reveal the
“portability” of the MoP and MoC triple bond functional
groups, attributable to their compatibility with the required
protic reaction conditions in concert with the protolytic sen-
Received 12 September 2004. Published on the NRC
Research Press Web site at http://canjchem.nrc.ca on
9 March 2005.
J.-P.F. Cherry, P.L. Diaconescu, and C.C. Cummins.2
Department of Chemistry, Room 2-227, Massachusetts
Institute of Technology, 77 Massachusetts Avenue,
Cambridge, MA 02139-4307, USA.
1This article is part of a Special Issue dedicated to Dinitrogen
Chemistry.
2Corresponding author (e-mail: ccummins@mit.edu).
Can. J. Chem. 83: 302–307 (2005)
doi: 10.1139/V05-025
© 2005 NRC Canada

Cherry et al.
303
Scheme 1.
sitivity of the molybdenum–amide bonds. In the present
work, we show that the same approach lends itself to the
synthesis of a diazenido trialkoxymolybdenum(IV) system.
magnetic derivative exhibits 1H and 13C NMR spectra
consistent with a single 1-adamantyl environment.
The specific choice of adamantanol in this work derives
from a combined consideration of steric bulk and solubility
properties. The steric protection afforded by adamantoxide
in complexes such as 2a·THF is often sufficient to favor a
mononuclear formulation, but in addition, such complexes
have sufficiently low solubility in saturated hydrocarbon me-
dia for efficient separation from the nonvolatile HN(i-Pr)Ar
aniline liberated in the alcoholysis reaction. In the latter re-
spect, adamantoxy is superior to, for example, tert-butoxy.
Adamantanolysis of 1a was also possible in the absence
of THF, under more forcing conditions (toluene, 92 °C,
39 h). In this case, the orange product precipitated from the
brown reaction mixture while still hot. The product obtained
in this manner (2a, 30% yield) was only sparingly soluble in
benzene, toluene, or chloroform, but dissolved quantitatively
in THF to provide solvate 2a·THF. The properties of sol-
vent-free 2a are reminiscent of those reported for nitrosyl
ONW(O-t-Bu)3 (31), and both compounds are presumably
polymeric in the solid state, though the nature of the bridg-
ing interactions is not known in either case. For 2a, it may
be surmised that the nucleophilic β-N atom of the diazenido
ligand serves to provide the bridging contact, leading to infi-
nite polymer formation. If so, then by analogy, the nitrosyl
oxygen in ONW(O-t-Bu)3 may behave similarly. Such struc-
tural features (i.e., topologically linear bridging N=NR or
NO) are of interest given the paucity of data concerning
such interactions (32), and their potential relevance to oxy-
gen-atom or nitrene-group transfer reactions (33).
Results and discussion
Prepared by treatment of the corresponding anionic
dinitrogen complex (29) (sodium salt) with, respectively,
methyl tosylate (MeOTs) and methyl chloroformate are the
diazenido complexes R1NNMo(N[i-Pr]Ar)3 1a (R1 = CH3,
synthesis and structure reported previously) (29) and 1b
(R1 = C(O)OMe). Gram quantities of 1a could be obtained
as red blocks in 58% isolated yield, as crystallized from
ether (23). In contrast, 1b was recovered in 94% yield as an
analytically pure dark oil that dissolves in benzene to give a
yellow solution.
+
The choice of MeOTs as the CH3 source in the synthesis
of 1a was not random (29). A mild and non-oxidizing
methylating agent is required to avoid both over-methylation
and 1e oxidation of the anionic dinitrogen complex to its la-
bile neutral counterpart (7). Furthermore, we had shown pre-
viously that sodium amalgam reduction of three-coordinate
Mo(N[t-Bu]Ar)3 in the presence of MeOTs under N2 consti-
tuted a one-pot synthesis of MeNNMo(N[t-Bu]Ar)3 (7).
Structural precedent for molecules containing the [N=N
C(O)OMe](1–) ligand, as found in 1b, is extant (30).
Adamantanolysis of 1a (Scheme 1) was accomplished by
treating with 3 equiv. of 1-AdOH in THF at –25 °C, fol-
lowed by warming to 25 °C and stirring for 4 h (Scheme 1).
Solvent removal in vacuo, followed by suspension in
pentane of the resulting orange solid, and subsequent collec-
tion by filtration, gave MeNNMo(OAd)3(THF) (2a·THF) in
81% isolated yield. The filtrate was shown to contain, essen-
tially exclusively, pure HN(i-Pr)Ar. A band at 1544 cm–1 in
the IR spectrum of 2a·THF is assigned to νNN, and this dia-
The molecular structure of 2a·THF (Fig. 1) was deter-
mined via single-crystal X-ray diffraction. The overall mo-
lecular conformation is quite reminiscent of that observed
for nitrosyl ONW(O-t-Bu)3(py) (31), with local threefold ax-
ial symmetry in the trialkoxymetal core, an apical metal–
ligand multiple bond, and a solvent adduct trans thereto. The
© 2005 NRC Canada

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Can. J. Chem. Vol. 83, 2005
Fig. 1. Thermal ellipsoid representation at 50% probability of
2a·THF. Selected interatomic distances (Å) and angles (°): Mo-
N1, 1.773(3); N1-N2, 1.250(4); Mo-O2, 1.902(2); Mo-O1s,
2.300(2); Mo-N1-N2, 171.8(3); N1-N2-C1, 118.7(3).
Fig. 2. Thermal ellipsoid representation at 50% probability of
[3a·THF][OTf] (disordered triflate anion omitted for clarity). Se-
lected interatomic distances (Å) and angles (°): Mo-N1, 1.745(3);
N1-N2, 1.296(5); Mo-O2, 1.860(3); Mo-O4, 2.297(3); Mo-N1-
N2, 177.2(3); N1-N2-C2, 119.5(4); N1-N2-C2, 120.0(4); C2-N2-
C1, 118.2(4).
key structural parameters for the diazenidomolybdenum core
in 2a·THF (see caption to Fig. 1) are essentially unperturbed
relative to those reported previously for 1a (26), indicating
that the exchange of alkoxide for anilide ligation, along with
the inclusion of a trans solvent molecule, alters little the api-
cal metal–ligand multiple bonding. The bond angles in the
diazenido core reveal sp and sp2 hybridization at, respec-
tively, N1 and N2, as is typical of this functional group. The
Mo-N1 distance is elongated by only ca. 0.1 Å relative to
values typical of terminal MoN triple bonds (6), such that
the resonance structure used to represent 2a·THF in
Scheme 1 is not by itself a complete description of the Mo—N
bonding.
While 1b was obtained only as a dark oil, its conversion
to a solid derivative was accomplished via room-temperature
adamantanolysis. Product 2b was obtained accordingly as a
yellow powder in 62% yield. The low solubility of 2b in to-
luene suggests that like 2a, the complex is polymeric in the
solid phase. While in 2a the β-N atom is likely to provide a
bridging contact, in the case of 2b, the carbonyl oxygen
atom in the carboxylmethyl residue may alternatively serve
this function. Carboethoxydiazenido molybdenum 3+ systems
have been obtained from O2Mo(dtc)2 (dtc = N,N-dimethyl-
dithiocarbamate) by treatment with the corresponding
hydrazine, or by ethylchloroformate derivitization of
dinitrogen complexes (N2)2Mo(dppe)2 (dppe = 1,2-diphenyl-
phosphinoethane) (34).
1.653(3) Å, an elongated N—N bond: N-N = 1.311(4) Å,
and near linearity at the α-N atom: V-N-N = 175.8(3)° (35).
While the structure of unsolvated [3]OTf is unknown,
solvate [3·THF]OTf was obtained straightforwardly and its
structure determined crystallographically (Fig. 2). Structural
parameters for the dimethylhydrazido ligand in [3·THF]OTf
are very similar to those seen for the aforementioned
triaryloxy vanadium system. Accordingly, the methylation
event leading to [3]OTf may be viewed as a redox event, the
metal undergoing a formal oxidation state change from 4+ to
6+ concomitantly. The bonding between metal and α-N is
then accurately described as for a metal imido complex (25).
On the other hand, donation of the dimethylamino lone pair
of electrons into the metal-α-N π* system leads to its ob-
served planarity and suggests the alternative formulation, as
drawn in Scheme 1 for the line drawings of [3]OTf and
[3·THF]OTf. A related, structurally characterized molybde-
num dimethylhydrazido complex cation was obtained by
methyl triflate treatment of a trimethylsilyldiazenido com-
plex (36).3
There has long been interest in the conversion of
dinitrogen-derived hydrazido systems to amines, and it has
been shown that treatment of cationic hydrazido complexes
with LiAlH4 can effect the conversion (37). Although not
Nucleophilicity of the β-N in 2a·THF was demonstrated
by reaction of the complex with methyl triflate. The triflate
salt [3]OTf was thereby produced as an orange powder in
82% isolated yield. Dimethylhydrazido complexes related to
[3]OTf include the triaryloxy system Me2NNV(dipp)3
(dipp = 2,6-diisopropylphenoxy) studied with reference to
vanadium-containing nitrogenase (35). The latter system dis-
played a short metal–nitrogen interatomic distance: V-N =
a
clean transformation, it has been shown that
[{ArN3N}MoNNMe2]OTf upon reduction with Na–Hg in
THF undergoes N—N bond cleavage producing nitride
[ArN3N]MoN together with dimethylamine and other prod-
ucts (38), implying that neutral dimethylhydrazido complex
[ArN3N]MoNNMe2 lacks sufficient stability for isolation.
Presumably, fragmentation of the latter neutral system leads
to nitride along with the [NMe2] radical, the latter being
3 Supplementary data may be purchased from the Directory of Unpublished Data, Document Delivery, CISTI, National Research Council
Canada, Ottawa, ON K1A 0S2, Canada (http://cisti-icist.nrc-cnrc.gc.ca/irm/unpub_e.shtml for information on ordering electronically).
CCDC 262546 and 262547 contain the crystallographic data for this manuscript. These data can be obtained, free of charge, via
ww.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).
© 2005 NRC Canada

Cherry et al.
305
1
capable of hydrogen atom abstraction from THF solvent
to produce dimethylamine. Sodium amalgam reduction of
dimethylhydrazido [Me2NNMo(N[t-Bu]Ar)3][OTf] likewise
gave rise to dimethylamine and the corresponding nitrido
complex, NMo(N[t-Bu]Ar)3 (7). Similarly, in the present
work we find (Scheme 1) that cobaltocene reduction of
[3]OTf produced cobaltocenium triflate, nitride NMo(O-1-
Ad)3, and dimethylamine, as determined spectroscopically.
Nitride NMo(O-1-Ad)3 was prepared independently using
the method described by Chisholm and co-workers (39) for
the synthesis of NMo(O-t-Bu)3, for determination of the
NMR spectroscopic characteristics of the former. The exis-
tence of neutral molybdenum(V) dimethylhydrazido com-
plexes has been probed for electrochemically (38), and such
systems remain interesting as putative reactive intermediates
in this manifold of amine-producing N—N bond cleavage
reactions.
1654, νCO 1212. H NMR (C6D6, 25 °C) δ: 6.46 (3H, para),
6.32 (6H, ortho), 4.81 (3H, methine), 3.62 (3H,
N2C(O)OCH3), 1.93 (18H, Ar-CH3). 13C NMR (C6D6,
25 °C) δ: 165.1 (N2C(O)OCH3), 148.0 (ipso), 138.8 (meta),
127.5 (ortho), 125.2 (para), 64.4 (CH(CH3)2), 52.6
(N2C(O)OCH3), 25.4 (CH(CH3)2), 21.7 (aryl-CH3). Anal.
calcd. for C35H51N5O2Mo: C 62.77, H 7.68, N 10.46; found:
C 62.55, H 7.79, N 10.41.
Synthesis of (AdO)3Mo(N2Me)(THF) (2a·THF) (41)
A solution of 1-adamantanol (667 mg, 4.38 mmol) in THF
(4 mL) was added to a solution of 1a (884 mg, 1.41 mmol)
in THF (8 mL) at –25 °C. The mixture was then stirred for
4.5 h at room temperature after which the solvent was
removed in vacuo. The resultant orange powder was sus-
pended in pentane and stirred for 20 min. This gave a sus-
pension that was chilled to –25 °C, and from which orange
powder was collected by filtration and washed with cold
pentane. The filtrate was subjected twice to the same con-
centration–suspension–cooling–washing procedure to maxi-
mize the yield. The combined orange precipitate was dried
in vacuo to yield 2a (759 mg, 81% yield). FT IR (THF,
Concluding remarks
Diazenido complexes synthesized from N2 in the context
of a simple supporting platform, namely the Mo(N[R]Ar)3
(R = i-Pr, Ar = 3,5-C6H3Me2) fragment, have been shown to
be amenable to replacement of the full complement of ancil-
lary ligands. Accordingly, trialkoxymolybdenum-supported
diazenido systems have become available for study, expand-
ing the scope of systems combining the chemistry of N2 or
N2-derived ligands with an O-donor supporting framework.
This approach, harnessing the portability of the diazenido-
molybdenum(3+) core, provides an opportunity to study this
functional group’s behavior in a variety of contexts.
KBr, cm–1): νNN 1544. H NMR (THF-d8, 25 °C) δ: 3.75
1
(3H, N2CH3), 3.60 (4H, THF), 2.13 (9H, CH), 1.92 (18H,
CH2), 1.76 (4H, THF), 1.66 (18H, CH2). 13C NMR (THF-d8,
25 °C) δ: 78.8 (OC(CH2-)3), 68.4 (THF), 47.6 (CH-CH2),
43.8 (N2CH3), 37.5 (C(CH2-)3), 32.7 (CH-CH2), 26.5 (THF).
Anal. calcd. for C35H56N2O4Mo: C 63.24, H 8.49, N 4.22;
found: C 63.16, H 8.4, N 4.16.
Synthesis of (AdO)3Mo(N2Me) (2a) (41)
(Ar[i-Pr]N)3MoN2Me (1a, 328 mg, 0.524 mmol), 1-
adamantanol (239 mg, 1.57 mmol), and toluene (12 mL)
were installed in a flask equipped with a Teflon stopcock.
The reaction mixture was stirred for 39 h at 92 °C. Then, the
mixture was cooled to –25 °C, and the resulting orange pre-
cipitate was filtered off and washed with cooled toluene to
Experimental
General considerations
All operations were performed in a drybox under an atmo-
sphere of purified nitrogen. Anhydrous ether, toluene, ben-
zene, pentane, and hexane were purified according to the
procedure of Grubbs and co-workers (40). Deuterated sol-
vents were degassed and dried over molecular sieves (4 Å)
and transferred under vacuum into a storage vessel. Molecu-
lar sieves (4 Å) and Celite® were activated in vacuo over-
night at a temperature above 180 °C. Other chemicals were
purified and dried by standard procedures or were used as
received. IR spectra were recorded on a Bio-Rad 135 Series
1
give 2a as an orange powder (92 mg, 30% yield). H NMR
(CDCl3, 25 °C) δ: 3.77 (3H, NNCH3), 2.10 (9H, CH), 1.88
(18H, CH2), 1.56 (18H, CH2). Anal. calcd. for C31H48N2O3Mo:
C 62.82, H 8.16, N 4.73; found: C 62.58, H 8.25, N 4.67.
Synthesis of (AdO)3MoNNC(O)OMe (2b) (41)
A toluene (4 mL) solution of (Ar[i-Pr]N)3MoN2C(O)OMe
(1b, 190 mg, 0.284 mmol) was added to 1-adamantanol
(134 mg, 0.879 mmol). The mixture was stirred for 12 h,
producing a yellow solution with a yellow precipitate. The
yellow precipitate was filtered off, washed with cold toluene,
and dried in vacuo to give 2b as a yellow powder (113 mg,
62% yield). FT IR (C6D6, KBr, cm–1) ν: 2915, 2852, 1113,
1086, 1061. 1H NMR (CDCl3, 25 °C) δ: 3.70 (3H, N2C(O)OCH3),
2.32 (9H, CH), 2.10 (18H, CH2), 1.65/1.62 (18H, CH2).
13C NMR (CDCl3, 25 °C) δ: 163.9 (N2C(O)OCH3), 86.8
(C(CH2-)3), 52.9 (CH-CH2), 45.4 (N2C(O)OCH3), 36.2 (C(CH2-)3),
31.9 (CH-CH2). Anal. calcd. for C32H48N2O5Mo: C 60.37, H
7.60, N 4.40; found: C 60.84, H 7.71, N 4.48.
FT IR spectrometer. H and 13C NMR spectra were recorded
1
on a Varian VXR-500, Varian Mercury-300, Varian XL-300,
or Varian Unity-300 spectrometer. H and 13C NMR chemi-
1
cal shifts are reported with reference to solvent resonances.
Dinitrogen complex [Na(THF)][N2Mo(N[i-Pr]Ar)3] and
compound 1a were prepared as previously reported (29, 41).
Synthesis of (Ar[i-Pr]N)3MoN2C(O)OMe (1b) (41)
To a solution of [Na(THF)][N2Mo(N[i-Pr]Ar)3] (151 mg,
0.214 mmol) in ether (8 mL) was added a solution of methyl
chloroformate (18 µL, 0.235 mmol) at –25 °C. The mixture
was allowed to warm to room temperature and was stirred
for a total of 3 h. The resultant mixture was filtered through
a pad of Celite® on a sintered glass frit. The solvent was re-
moved from the filtrate in vacuo to give 1b as a dark brown
oil (135 mg, 94% yield). FT IR (C6D6, KBr, cm–1): νNN
Synthesis of [(AdO)3Mo(NNMe2)][OTf] ([3][Otf]) (41)
Methyl triflate (258 µL, 2.28 mmol) was added to a tolu-
ene (8 mL) suspension of (AdO)3MoN2Me(THF) (2a·THF,
759 mg, 1.14 mmol) at –25 °C. The mixture was stirred for
© 2005 NRC Canada

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Can. J. Chem. Vol. 83, 2005
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3 h at room temperature. The resultant purple-red mixture
was filtered through Celite® and the solvent was removed
from the filtrate in vacuo. The crude red solid thereby
obtained was suspended in ether–pentane 1:1 and cooled to
–25 °C. An orange precipitate of [3][OTf] was collected by
filtration and dried in vacuo (709 mg, 82%). FT IR (C6D6,
KBr, cm–1) ν: 2915, 2852, 1113, 1086, 1061. 1H NMR
(C6D6, 25 °C) δ: 3.34 (6H, NN(CH3)2), 2.11 (9H, CH), 2.06
(18H, CH2), 1.52/1.49 (18H, CH2). 13C NMR (C6D6, 25 °C)
δ: 86.6 (C(CH2-)3), 45.8 (CH-CH2), 45.3 (NN(CH3)2), 36.6
(C(CH2-)3), 32.0 (CH-CH2). Anal. calcd. for C33H51N2O6F3SMo:
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([3·THF][OTf]) (41)
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was obtained simply by dissolving [3]OTf in THF. Unlike
2a·THF, the THF ligand in [3·THF][OTf] can be removed by
simply dissolving the complex in toluene and removing the
solvent. A single crystal suitable for X-ray structure analysis
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1
was obtained by recrystallization from toluene–THF. H NMR
(C6D6, 25 °C) δ: 3.76 (4H, THF), 3.46 (6H, NN(CH3)2), 2.12
(9H, CH), 2.00 (18H, CH2), 1.57/1.54 (18H, CH2), 1.48 (4H,
THF).
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Independent synthesis of (AdO)3MoN (41)
Sodium azide (801 mg, 12.3 mmol) was added to a THF
(50 mL) suspension of MoCl4(THF)2 (3.92 g, 10.3 mmol) at
room temperature, and the mixture was stirred for 1 h. Then,
Li(OAd) (4.74 g, 30.0 mmol) was added, and the mixture
was stirred for 4 h at room temperature. The resulting mix-
ture was filtered through Celite®, and the solvent was re-
moved from the filtrate to give a dark, red-brown solid. The
solid was stirred in boiling toluene (125 mL) and filtered
through a pad of Celite® on a sintered glass frit, and the
solid collected on the frit was washed with toluene. The fil-
trate was condensed and allowed to stand at room tempera-
ture for 36 h. The white precipitate was collected by filtration,
washed with pentane, and dried in vacuo. The resulting pow-
der was further suspended in cold toluene (25 mL), collected
by filtration, and dried in vacuo to give (AdO)3MoN as a
white powder (0.98 g, 17% yield). FT IR (pyridine-d5,
KBr, cm–1) ν: 2938, 2893, 2851, 1453, 1104, 1077, 940,
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(1978).
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22. M. Hidai and Y. Mizobe. React. Coord. Ligands, 2, 53 (1989).
23. G.J. Leigh and N. Winterton (Editors). Modern coordination
chemistry — The legacy of Joseph Chatt. Royal Society of
Chemistry, Cambridge. 2002.
24. B.A. MacKay and M.D. Fryzuk. Chem. Rev. 104, 385 (2004).
25. D.L. DuBois and R. Hoffmann. Nouv. J. Chim. 1, 479 (1977).
26. F.H. Stephens, J.S. Figueroa, P.L. Diaconescu, and C.C. Cummins.
J. Am. Chem. Soc. 125, 9264 (2003).
1
745. H NMR (pyridine-d5, 25 °C) δ: 2.24 (18H, CH2), 2.17
(9H, CH), 1.63/1.61 (18H, CH2). 13C NMR (pyridine-d5,
25 °C) δ: 78.1 (C(CH2-)3), 46.1 (CH-CH2), 36.9 (C(CH2-)3),
32.0 (CH-CH2). Anal. calcd. for C30H45NO3Mo: C 63.93, H
8.05, N 2.49; found: C 64.06, H 8.12, N 2.58.
27. Y.-C. Tsai, P.L. Diaconescu, and C.C. Cummins. Organo-
metallics, 19, 5260 (2000).
28. J.M. Blackwell, J.S. Figueroa, F.H. Stephens, and C.C.
Cummins. Organometallics, 22, 3351 (2003).
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and C.C. Cummins. Inorg. Chem. 40, 6860 (2001).
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32. No examples of either turned up in a search of the Cambridge
Structural Database. On the other hand, some transition-metal
nitrosyl complexes are known to interact with Lewis acids
(e.g., BF3) at their nitrosyl oxygen atom. For a structurally
characterized example see: W.B. Sharp, P. Legzdins, and B.O.
Patrick. J. Am. Chem. Soc. 123, 8143 (2001).
Acknowledgments
The authors wish to thank Joshua S. Figueroa and Tetsuro
Murahashi for technical assistance. We are also grateful to
the United States National Science Foundation for funding
this work (grant CHE-0316823).
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