Nitric oxide insertion reactivity with the bismuth-carbon bond: Formation of the oximate anion, [ON=(C6H2tBu2O)]-, from the oxyaryl dianion, (C6H2tBu2O)2-

Article abstract of DOI:10.1002/chem.201404910

The first example of NO insertion into a Bi-C bond has been found in the direct reaction of NO with a Bi³⁺ complex of the unusual (C₆H₂tBu₂-3,5-O-4)^2- oxyaryl dianionic ligand, namely, Ar′Bi(C₆H₂tBu₂-3,5-O-4) [Ar′=2,6-(Me₂NCH₂)₂C₆H₃] (1). The oximate complexes [Ar′Bi(ONC₆H₂-3,5-tBu₂-4-O)]₂(μ-O) (3) and Ar′Bi(ONC₆H₂-3,5-tBu₂-4-O)₂ (4) were formed as a mixture, but can be isolated in pure form by reaction of NO with a Bi³⁺ complex of the [O₂C(C₆H₂tBu₂-3-5-O-4]^2- oxyarylcarboxy dianion, namely, Ar′Bi-[O₂C(C₆H₂tBu₂-3-5-O-4)-κ²O,O′]. Reaction of 1 with Ph₃CSNO gave an oximate product with (Ph₃CS)^1- as an ancillary ligand, (Ph₃CS)(Ar′)Bi(ONC₆H₂-3,5-tBu₂-4-O) (5).

Full text of DOI:10.1002/chem.201404910

DOI: 10.1002/chem.201404910
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&
Small-Molecule Activation
Nitric Oxide Insertion Reactivity with the Bismuth–Carbon Bond:
Formation of the Oximate Anion, [ON=(C6H2tBu2O)]1ꢀ, from the
Oxyaryl Dianion, (C6H2tBu2O)2ꢀ
Douglas R. Kindra, Ian J. Casely, Joseph W. Ziller, and William J. Evans*[a]
Abstract: The first example of NO insertion into a BiꢀC
bond has been found in the direct reaction of NO with
a Bi3+ complex of the unusual (C6H2tBu2-3,5-O-4)2ꢀ oxyaryl
dianionic ligand, namely, Ar’Bi(C6H2tBu2-3,5-O-4) [Ar’=2,6-
(Me2NCH2)2C6H3] (1). The oximate complexes [Ar’Bi(ONC6H2-
3,5-tBu2-4-O)]2(m-O) (3) and Ar’Bi(ONC6H2-3,5-tBu2-4-O)2 (4)
were formed as a mixture, but can be isolated in pure form
by reaction of NO with a Bi3+ complex of the [O2C(C6H2tBu2-
3-5-O-4]2ꢀ
oxyarylcarboxy
dianion,
namely,
Ar’Bi-
[O2C(C6H2tBu2-3-5-O-4)-k2O,O’]. Reaction of 1 with Ph3CSNO
gave an oximate product with (Ph3CS)1ꢀ as an ancillary
ligand, (Ph3CS)(Ar’)Bi(ONC6H2-3,5-tBu2-4-O) (5).
Introduction
Nitric oxide, NO, is a simple het-
erodiatomic molecule that is crit-
ical in many areas of science and
technology.[1] It is a significant
component in the atmospheric
chemistry of smog,[2] the indus-
trial chemistry of nitric acid and
Scheme 1. Synthesis of Ar’Bi(C6H2tBu2-3,5-O-4) (1) and the reaction between 1 and CO2.[9,10]
its derivatives,[3] and the biologi-
cal chemistry of physiological
processes related to nerve im-
pulse, blood pressure, and immune systems.[4] The radical
nature of NO allows both oxidation to (NO)1+ and reduction to
(NO)1ꢀ to occur, whereas in biological systems, a protonated
form designated HNO is accessible.[5] Recently, the first exam-
ple of an (NO)2ꢀ complex was identified.[6]
to BiPh3 which, when exposed to 1 atm of NO gas for 24 h,
shows no reaction.
To fully identify the reaction products of this direct reaction
of NO gas with the oxyaryl bismuth–carbon linkage in 1, inde-
pendent syntheses were carried out with the NO delivery re-
agent Ph3CSNO and with the previously reported bismuth
complex of the oxyarylcarboxy dianion, [O2C(C6H2tBu2-3-5-O-
4)]2ꢀ, 2, formed from 1 and CO2 (Scheme 1).[10] This has led to
the first examples of NO insertion into a bismuth–carbon
bond, unusual NO insertion chemistry, and structural data on
Due to this extensive chemistry, the reactivity of NO has
been thoroughly examined with most of the elements in the
periodic table.[7] An exception is with bismuth, a metal that his-
torically has been understudied.[8] We now report bismuth NO
chemistry and specifically, the NO reactivity of the previously
reported Ar’Bi(C6H2tBu2-3,5-O-4), 1, [Ar’=2,6-(Me2NCH2)2C6H3],
a Bi3+ complex of the unusual oxyaryl dianion, (C6H2tBu2O)2ꢀ.[9]
The reactivity of NO was of interest to probe the chemistry of
the BiꢀC bond of this dianionic ligand that is generated by Cꢀ
H bond activation and rearrangement from the reaction of
KOC6H3tBu2-2,6 with the NCN pincer stabilized bismuth dichlor-
ide, Ar’BiCl2 (Scheme 1).[9] Complex 1 reacts with NO in contrast
the quinoidal oximate ligand, [ON=(C6H2tBu2O)]1ꢀ [11]
.
Results and Discussion
A
red acetonitrile solution of the oxyaryl complex,
Ar’Bi(C6H2tBu2-3,5-O-4), 1,[9] reacted with NO at 1 atm to form
a dark green solution that contains multiple products identi-
1
fied by H NMR spectroscopy. Reactions conducted at low tem-
perature (ꢀ358C) and with stoichiometric amounts of NO gas
also gave complicated product mixtures. However, from the
room temperature reaction, yellow crystals of [Ar’Bi(ONC6H2-
3,5-tBu2-4-O)]2(m-O) (3) were obtained at ꢀ308C from the crude
acetonitrile reaction mixture (Figure 1). Subsequently, yellow
crystals of Ar’Bi(ONC6H2-3,5-tBu2-4-O)2, 4, were obtained at
[a] Dr. D. R. Kindra, Dr. I. J. Casely, Dr. J. W. Ziller, Prof. W. J. Evans
Department of Chemistry, University of California
Irvine, CA 92697-2025 (USA)
E-mail: wevans@uci.edu
Supporting information for this article is available on the WWW under
http://dx.doi.org/10.1002/chem.201404910.
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[NO][X] reagents, such as
[NO][BF4], are far more common
than insertion reactions with
nitric oxide gas.[14]
In Equation (1), the formal in-
sertion of NO into the BiꢀC
bond of the (C6H2tBu2-3,5-O-4)2ꢀ
dianion generates the oximate
ligand,
[ON=(C6H2tBu2O)]1ꢀ
,
which is present in both 3 and
4. The sodium salt of this oxi-
mate has been described as an
intermediate formed in solution
in reactions of NO with pheno-
lates,[11] but to our knowledge, it
has not been previously isolated.
Figure 1. ORTEP[12] representation of [Ar’Bi(ONC6H2-3,5-tBu2-4-O)]2(m-O) (3) from two perspectives, with thermal el-
lipsoids drawn at the 50% probability level. Hydrogen atoms are omitted for clarity. The two bismuth centers are
bound by a bridging oxygen (O1).
Compound
3
contains two
[Ar’Bi(oximate)]1+ moieties linked by a bridging oxide, whereas
4 contains two oximate units bound to a single [Ar’Bi]2+
moiety. Because the NꢀO bond order in the oximate is one,
the oxyaryl dianion is formally oxidized and the NO reduced in
the reaction. Conversion of the oxyaryl dianion in 1 to the oxi-
mate monoanion creates a charge imbalance at the Bi3+
center allowing coordination of the oxide ligand in 3. The
origin of the oxide is unknown, but it could arise from another
equivalent of NO acting as an oxygen-delivery agent. The pres-
ence of the two oxyaryl-dianion-derived oximate ligands in 4
indicates that ligand redistribution is occurring under the reac-
tion conditions.
Figure 2. ORTEP representation of Ar’Bi(ONC6H2-3,5-tBu2-4-O)2 (4) with ther-
mal ellipsoids drawn at 50% probability level. Hydrogen atoms are omitted
for clarity.
Because 3 and 4 were formed as a mixture shown in Equa-
tion (1), efforts were made to synthesize them in pure form
from other precursors. The oxyarylcarboxy complex, Ar’Bi-
[O2C(C6H2tBu2-3-5-O-4)-k2O,O’], 2, formed from 1 and CO2,[10]
had previously been shown to undergo facile decarboxylation
under mild conditions in a reaction with I2,[15] and therefore
had the potential to act as a surrogate for 1. Accordingly, its
reactivity with NO was exam-
room temperature from the same mother liquor (Figure 2). The
structures of these products were defined by X-ray crystallog-
raphy, and the NO insertion reaction chemistry is shown in
Equation (1).
ined. Compound 2 reacts with
NO at atmospheric pressure to
form an emerald green solution
similar to that of the reaction
mixture shown in Equation (1).
Yellow crystals identified as 3 by
X-ray crystallography were isolat-
ed in >90% yield [Eq. (2)], and
allowed this oximate complex to
be spectroscopically character-
ized in pure form (see below).
When the reaction was per-
formed in deuterated solvents in
The reaction involves a relatively rare example of insertion
into an MꢀX bond by NO gas.[7a] Although NO is highly reac-
tive, it typically reacts[13] either as a) an oxidant to form com-
plexes of (NO)1ꢀ; b) as a reductant to form complexes of
(NO)1+; or c) as an oxide delivery agent. Migratory insertion of
bound (NO)1ꢁ ligands and insertion of (NO)+ by reaction with
a sealed J. Young NMR tube, free carbon dioxide could be ob-
served in the 13C NMR spectrum, confirming decarboxylation of
the [O2C(C6H2tBu2-3-5-O-4)]2ꢀ ligand in 2 as part of the reaction
process.
The isolation of pure 3 allowed the development of a route
to isolate 4. Reaction of 3 with two equivalents of either
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bonds, in which one arm of each pincer ligand has
typical bond lengths (2.629(4) and 2.636(4) ꢁ), where-
as the other is much longer (2.845(4) and 2.910(4) ꢁ).
The latter long bond lengths are still within the sum
of the van der Waals radii of 3.9 ꢁ, but suggest less
interaction as is sometimes observed with Ar’Bi2+
complexes.[10,20] This is part of the flexible nature of
the Ar’ ligand.
The first structural data on the [ON=(C6H2tBu2O)]1ꢀ
oximate ligand, obtained in complexes 3–5, revealed metrical
parameters that are consistent with the quiniodal structures
drawn in Equations [1–4]. These are shown in Figure 4 in com-
parison with the dianionic li-
[Et3NH][Cl] or Me3SiCl forms primarily one equivalent of Ar’BiCl2
and one equivalent of 4, as was identified by NMR spectrosco-
py and X-ray crystallography [Eq. (3)].
gands in 1 and 2. Two values are
shown for each distance in 3
and 4, because they have two
oximate ligands per molecule.
Two of the CꢀC bonds in each
of the [ON=(C6H2tBu2O)]1ꢀ li-
gands in 3–5 are in the 1.347 to
1.358 ꢁ range of a double bond
and the CꢀO bond lengths,
Again, ligand redistribution is apparently involved. Although
a mixture was formed, as shown in Equation (3), separation is
now possible, because Ar’BiCl2 is much less soluble in THF, and
this allows 4 to be isolated in 45% yield with respect to bis-
muth. It is fortunate that the kinetics of these reactions allow
the isolation of 4, because it also reacts with both [Et3NH][Cl]
and Me3SiCl to make Ar’BiCl2.
An additional by-product isolated from Equation (2) was
a small amount of the polymeric carbonate species [Ar’Bi(m-
k1:k2-CO3)]n, as was identified by X-ray crystallography.[16] For-
mation of the carbonate as a minor product is reasonable, be-
cause free CO2 is observed in the reaction vessel, and oxide
formation was observed in the NO reaction [Eq. (1)]. Resonan-
ces consistent with small amounts of (Me3Si)2O[17] and the sily-
lated oximate, Me3SiON=(C6H2tBu2O), were observed by
1H NMR and GC-MS techniques when 3 was reacted with
Me3SiCl.
Another approach to avoid the complicated mixture of
products from the NO reaction [Eq. (1)] was to examine reac-
tions with the alternative NO source, Ph3CSNO.[18] This reagent
reacted with 1 to form another fully characterized complex of
the oximate ligand, the bright orange (Ph3CS)(Ar’)Bi(ONC6H2-
3,5-tBu2-4-O) (5). This complex can be obtained cleanly in
>90% yield [Eq. (4)] and was crystallographically identified
(Figure 3). In this case, the “[Ar’Bi(ONC6H2tBu2O)]1+” unit was
trapped by a (Ph3CS)ꢀ ligand before ligand redistribution or co-
ordination to oxide occurred, as was found in Equation (1).
This demonstrates the value of the Ph3CSNO reagent as a sub-
stitute for NO.
The structures of 3–5 contain [Ar’Bi]2+ moieties with conven-
tional BiꢀC(Ar’) bond lengths ranging from 2.184(3) to
2.235(4) ꢁ.[10] The 2.493(3) to 2.576(3) ꢁ BiꢀN bond lengths of
the pincer arms in 4 and 5 are also typical for [Ar’Bi]2+ com-
pounds.[10,16,19] However, in 3, there is asymmetry in its BiꢀN
Figure 3. ORTEP representation of (Ph3CS)(Ar’)Bi(ONC6H2-3,5-tBu2-4-O) (5)
from two perspectives, with thermal ellipsoids drawn at the 50% probability
level. Hydrogen atoms are omitted for clarity.
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1H NMR spectroscopy on the
pure oximate products showed
a 1:1 ratio of [ON=(C6H2tBu2O)]1ꢀ
to Ar’ resonances for 3 that is
qualitatively similar to the spec-
trum of 4, which has a 2:1 ratio
1
of resonances. The H NMR spec-
trum of 5 differs in that the reso-
nances of the methylene pro-
tons of the Ar’ ligand are split as
is found for 1,[10] as well as some
other Ar’Bi2+ compounds in the
literature.[9,10,22] Compounds 2–4
did not show this splitting of the
Ar’ ligand resonances, even
though the solid-state structure
of 3 showed two different types
of BiꢀN distances.
The UV/Vis spectrum of
3
showed a solvent dependence
not found for 1, 2, 4, and 5. In
THF and MeCN, complex 3 is
green due to an absorption at
l=639 nm (e=2900mꢀ1 cmꢀ1)
Figure 4. Bond distances in the oximate ligands of compounds 3, 4, and 5 compared to the dianionic oxyaryl and
oxyarylcarboxy ligands in 1 and 2, respectively. Compounds containing two oximate ligands (3 and 4) list both
distances for each bond.
1.232 to 1.239 ꢁ, are also in the double-bond range.[21] In con-
trast, structures of the dianionic ligands in 1 and 2 are more
delocalized.
in THF and 634 nm (e=1600mꢀ1 cmꢀ1) in MeCN, in addition to
the maxima at approximately 375 nm (80000mꢀ1 cmꢀ1). The
second absorption is not observed when 3 is dissolved in tolu-
ene, diethyl ether, or dichloromethane and 3 is yellow. In con-
trast, the yellow orange complexes, 1, 2, 4, and 5, each show
only single maxima at l=467 nm (6900mꢀ1 cmꢀ1), 379 nm
(61700mꢀ1 cmꢀ1), 397 nm (37400mꢀ1 cmꢀ1), and 357 nm
(15700mꢀ1 cmꢀ1), respectively. The large molar absorptivity
values are consistent with p–p* transitions.[23]
The analogous CꢀC distances in 1 and 2 are longer, 1.372(3)
to 1.384(3) ꢁ, as are the CꢀO bond lengths, 1.265(4) to
1.278(2).[10] The 1.315(4) to 1.336(4) ꢁ CꢀN bonds in 3–5 are
slightly longer than those typically found in organic oximes,
R2C=NOH (1.281 ꢁ),[21] and the 1.317(4) to 1.349(3) ꢁ NꢀO
bonds of the inserted (NO)1ꢀ moiety are in the single-bond
range.[21]
Although the structural parameters are consistent in 3–5
and the Bi-C(Ar’) distances of each are conventional, the BiꢀO-
(oximate) bonds vary significantly in the three complexes as
do the Bi-O-N angles: 2.277(3) ꢁ [108.6(2)8] and 2.284(3) ꢁ
[103.1(2)8] for 3, 2.295(2) ꢁ [105.55(16)8] and 2.364(2) ꢁ
[99.81(17)8] for 4, and 2.455(2) ꢁ [95.82(18)8] for 5. More acute
Bi-O-N angles were found with the longer distances in 4 and 5.
In comparison to these BiꢀO lengths, the 2.053(3) and
2.090(3) ꢁ BiꢀO(oxide) distances in 3 are much shorter. The
pairs of BiꢀO(oximate) distances in 4 and the two BiꢀO(oxide)
distances in 3 show a surprising disparity within the pair con-
sidering they are from chemically equivalent bonds. In compar-
ison, the Ar’Bi(OC6H3R2-2,6)2 series have BiꢀO bonds that fall in
a narrow range: 2.2972(17) and 2.3068(17) ꢁ for R=Me,
2.2969(16) and 2.3000(16) ꢁ for R=iPr, and 2.350(3) and
2.321(3) ꢁ for Ar’Bi(OC6H2tBu2-2,6-Me-4)2.[9] The larger BiꢀO dis-
Conclusion
The reaction of NO with the oxyaryl dianion complex,
Ar’Bi(C6H2tBu2-3,5-O-4) (1), has provided the first example of
NO insertion into a BiꢀC bond. This has led to the first fully
characterized
examples
of
the
oximate
ligand,
[ON=(C6H2tBu2O)]1ꢀ in three different molecules, namely,
[Ar’Bi(ONC6H2-3,5-tBu2-4-O)]2(m-O) (3), Ar’Bi(ONC6H2-3,5-tBu2-
4-O)2 (4), and (Ph3CS)(Ar’)Bi(ONC6H2-3,5-tBu2-4-O) (5). Although
the CꢀC and CꢀO distances in these quinoidal oximates are
similar, their BiꢀO distances show surprising variation. The utili-
ty of carboxyaryloxy Ar’Bi[O2C(C6H2tBu2-3-5-O-4)-k2O,O’] and
Ph3CSNO as synthetic substitutes for 1 and NO, respectively,
was also demonstrated.
tance in 5 may arise due to the large size of the (Ph3CS)1ꢀ
Experimental Section
[16]
ligand. However, [Ar’Bi(m-k1:k2-CO3)]n
also has long BiꢀO
All manipulations and syntheses described below were conducted
with the rigorous exclusion of air and water by using standard
Schlenk line and glovebox techniques under an argon or dinitro-
gen atmosphere. Solvents were sparged with ultra high-purity
(UHP) argon and dried by passage through columns containing Q-
5 and molecular sieves prior to use. Deuterated NMR solvents were
bonds of 2.402(7), 2.411(8), and 2.412(7) ꢁ. Overall, these struc-
tures demonstrate the flexibility of the (Ar’Bi)2+ unit to stabilize
a diverse set of aryloxide-derived ligands with both localized
and delocalized structures and variable BiꢀO bond distances.
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dried over NaK alloy, degassed by three freeze/pump/thaw cycles,
and vacuum transferred before use. H NMR spectra were recorded
stirring overnight, the reaction mixture was a dark yellow solution.
The solvent was removed under vacuum leaving off-white solids
that were stirred in a THF/n-hexane (2:3) solution. White solids
were separated from the yellow supernatant by centrifugation and
dried. The insoluble white solids were identified as the known
Ar’BiCl2 by 1H NMR spectroscopy.[19] The soluble fraction upon
drying gave an orange sticky solid, which was washed with n-
hexane to give 3 as an orange solid (77 mg, 45% yield with respect
1
on Bruker DR400, GN500, or CRYO500 MHz spectrometers (13C NMR
spectra on the 500 MHz spectrometer operating at 125 MHz) at
298 K unless otherwise stated and referenced internally to residual
protio-solvent resonances. IR samples were prepared as KBr pellets
on a Varian 1000 FTIR system. Elemental analyses were conducted
on a PerkinElmer 2400 Series II CHNS elemental analyzer and
proved to be problematic with the oximate complexes compared
to other Ar’Bi complexes. Incomplete combustion was often ob-
served and multiple samples had to be analyzed. Nitric oxide (NO)
gas was purchased from Aldrich (98.5%) and was passed through
two U-shaped glass columns connected in series and cooled to
ꢀ788C before use. [Et3NH][Cl] (ꢂ99%) (Sigma–Aldrich) was used as
purchased. Ph3CSNO,[18] Ar’Bi(C6H2tBu2-3,5-O-4) (1),[10] and
Ar’Bi[O2C(C6H2tBu2-3–5-O-4)-k2O,O’] (2),[10] were prepared according
to the literature.
1
to bismuth). H NMR (500 MHz, [D3]acetonitrile): d=7.79 [d, 2H, m-
(Me2NCH2)2C6H3], 7.58 [t, 1H, p-(Me2NCH2)2C6H3], 7.42 [s, 2H, ON=
(C6H2tBu2O)], 7.11 [s, 2H, ON=(C6H2tBu2O)], 4.29 [s, 4H,
(Me2NCH2)2C6H3], 2.65 [s, 12H, (Me2NCH2)2C6H3], 1.28 [s, 18H, ON=
(C6H2tBu2O)], 1.22 ppm [s, 18H, ON=(C6H2tBu2O)]; 13C NMR
(125 MHz, [D3]acetonitrile): d=187.9, 138.9, 132.9, 130.4, 129.2,
117.0, and 112.5 [(Me2NCH2)2C6H3 and ON=(C6H2tBu2O)], 68.9
[(Me2NCH2)2C6H3], 47.0 [br s, (Me2NCH2)2C6H3], 36.1 [q-ON=
(C6H2(CMe3)2O)], 35.6 [q-ON=(C6H2(CMe3)2O)], 29.8 ppm [ON=
(C6H2(CMe3)2O)]; IR (KBr): u˜ =2957 s, 2918 m, 2867 m, 1608 s,
1455 s, 1388w, 1356 s, 1299 s, 1248 s, 1091 m, 1055 s, 1014 s, 924 s,
883 m, 840 m, 746w, 709 mcmꢀ1; elemental analysis calcd (%) for
C40H59BiN4O4 (868.92): C 55.29, H 6.84, N 6.45; found: C 55.65, H
7.13, N 6.44. Crystals of 3 suitable for X-ray crystallography analysis
were grown from a concentrated acetonitrile solution at RT.
Reaction of Ar’Bi(C6H2tBu2-3,5-O-4) (1) with NO
A 100 mL Schlenk flask fitted with a high-vacuum Teflon stopcock
was charged with a red solution of 1 (100 mg, 0.17 mmol) in aceto-
nitrile (10 mL). The flask was placed on a high-vacuum line, de-
gassed, and charged with 1 atm of NO. After stirring at RT for 1 h,
a dark green mixture was formed. The flask was degassed with
three freeze/pump/thaw cycles and transferred to an argon-filled
glovebox. Yellow crystals of [Ar’Bi(ONC6H2-3,5-tBu2-4-O)]2(m-O) (3)
suitable for X-ray diffraction analysis were isolated from a concen-
trated acetonitrile solution at ꢀ308C. Subsequently, yellow crystals
of Ar’Bi(ONC6H2-3,5-tBu2-4-O)2 (4) suitable for X-ray diffraction anal-
ysis were isolated from a concentrated acetonitrile solution in an
NMR tube that was left at RT for two days.
Synthesis of Ar’Bi(ONC6H2-3,5-tBu2-4-O)2 (4) from 3 and
Me3SiCl
Neat Me3SiCl (25 mL, 0.20 mmol) was added by microsyringe to
a stirred emerald green solution of 3 (120 mg, 0.10 mmol) in THF
(12 mL), which gave a rapid color change to yellow. After stirring
overnight, the yellow reaction mixture was dried under reduced
pressure, and the crude product was stirred in n-hexane (10 mL)
for 1 h. Separation by centrifugation gave off-white insoluble mate-
rial, which was identified as Ar’BiCl2 by NMR spectroscopy.[19] The
n-hexane-soluble yellow solids were identified as 4 by X-ray crystal-
lography and NMR spectroscopy.
Synthesis of [Ar’Bi(ONC6H2-3,5-tBu2-4-O)]2(m-O) (3)
A Schlenk flask (100 mL) fitted with a high-vacuum Teflon stopcock
was charged with a yellow suspension of 2 (100 mg, 0.154 mmol)
in THF (12 mL). The flask was placed on a high-vacuum line, de-
gassed, and charged with 1 atm of NO. After stirring at RT for 1 h,
a dark red solution formed. The reaction mixture was stirred over-
night and then degassed. Upon degassing a rapid color change to
emerald green was effected. The flask was transferred to an argon-
filled glovebox and the solvent was removed under reduced pres-
sure to give 3 as a green solid (90 mg, 91%). 1H NMR (500 MHz,
[D3]acetonitrile): d=7.69 [d, 4H, m-(Me2NCH2)2C6H3], 7.55 [t, 2H, p-
(Me2NCH2)2C6H3], 7.36 [s, 2H, ON=(C6H2tBu2O)], 7.20 [s, 2H, ON=
(C6H2tBu2O)], 4.20 [s, 8H, (Me2NCH2)2C6H3], 2.57 [s, 24H,
(Me2NCH2)2C6H3], 1.29 [s, 18H, ON=(C6H2tBu2O)], 1.20 ppm [s, 18H,
ON=(C6H2tBu2O)]; 13C NMR (125 MHz, [D3]acetonitrile): d=187.9,
156.0, 134.1, 130.8, 129.2, 116.6 [(Me2NCH2)2C6H3 and ON=
(C6H2tBu2O)], 68.7 [(Me2NCH2)2C6H3], 46.2 [br s, (Me2NCH2)2C6H3],
36.2 [q-ON=(C6H2(CMe3)2O)], 35.8 [q-ON=(C6H2(CMe3)2O)], 30.1 ppm
[ON=(C6H2(CMe3)2O)]; IR (KBr): u˜ =2954 s, 2924 s, 2858 s, 1604 m,
1453 s, 1357 s, 1296 s, 1247 s, 1103 m, 1060 m, 1016 s, 927 s, 883w,
Synthesis of (Ph3CS)(Ar’)Bi(ONC6H2-3,5-tBu2-4-O) (5) from 1
A green solution of Ph3CSNO (50 mg, 0.17 mmol) in THF (6 mL)
was added to a stirred dark red solution of 1 (100 mg, 0.17 mmol)
in THF (4 mL). The solution turned light orange after 1 h. After stir-
ring overnight, solvent was removed under vacuum to give a red
sticky solid. This crude product was washed with n-hexane to give
5 as a bright orange powder (140 mg, 93%). 1H NMR (500 MHz,
[D6]benzene): d=7.82 [d, 6H, m-(C6H5)3CS], 7.72 [s, 1H, ON=
(C6H2tBu2O)], 7.66 [s, 1H, ON=(C6H2tBu2O)], 7.28 [d, 2H, m-
(Me2NCH2)2C6H3], 7.14 [m, 6H, o-(C6H5)3CS], 7.02 [t, 3H, p-(C6H5)3CS],
6.96 [t, 1H, p-(Me2NCH2)2C6H3] 3.85 [d, 2H, (Me2NCH2)2C6H3], 3.78
[d, 2H, (Me2NCH2)2C6H3], 2.13 [br s, 12H, (Me2NCH2)2C6H3], 1.62 [s,
9H, ON=(C6H2tBu2O)], 1.43 [s, 9H, ON=(C6H2tBu2O)]. 13C NMR
(125 MHz, [D6]benzene): d=205.5, 187.1, 155.9, 152.7, 147.8, 134.3,
131.5, 130.3, 129.1, and 115.7 [(Me2NCH2)2C6H3 and ON=
840 mcmꢀ1
; elemental analysis calcd (%) for C52H78Bi2N6O5
(C6H2tBu2O)]
[(Me2NCH2)2C6H3], 46.2 [br s, (Me2NCH2)2C6H3], 36.0 [ON=
(C6H2(CMe3)2O)], 35.6 [q-ON=(C6H2(CMe3)2O)], 30.3 [ON=
144.9
[(C6H5)3CS],
126.6
[(C6H5)3CS],
69.0
(1285.16): C 48.60, H 6.12, N 6.54; found: C 47.11, H 6.02, N 6.35.
Yellow crystals suitable for X-ray diffraction analysis were grown
from a concentrated acetonitrile solution at ꢀ308C.
(C6H2(CMe3)2O)]. IR (KBr): u˜ =2954 m, 2864 m, 1588 s, 1485 s,
1447 s, 1356 s, 1293 s, 1245 s, 1116 s, 1074 m, 1017 m, 940 s, 885w,
841 m, 745 m, 703 scmꢀ1; the sample for elemental analysis was re-
crystallized from THF as a THF solvate: elemental analysis calcd for
C45H54BiN3O2S·C4H8O (982.09): C 59.93, H 6.36, N 4.28; found: C
60.78, H 6.08, N 3.56. Crystals suitable for X-ray crystallography
were grown from a saturated acetonitrile solution at RT.
Synthesis of Ar’Bi(ONC6H2-3,5-tBu2-4-O)2 (4) from 3 and
[Et3NH][Cl]
Solid [Et3NH][Cl] (26.6 mg, 0.19 mmol) was added to a stirred emer-
ald green solution of 3 (124 mg, 0.10 mmol) in THF (10 mL). After
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Synthesis of (Ph3CS)(Ar’)Bi(ONC6H2-3,5-tBu2-4-O) (5) from 2
Keywords: bismuth · nitric oxide · oximates · oxyaryl dianion ·
A green solution of Ph3CSNO (26 mg, 0.08 mmol) in THF (2 mL)
was added to a stirred yellow suspension of 2 (55 mg, 0.08 mmol)
in THF (8 mL). After stirring overnight, the red reaction mixture was
dried under reduced pressure to give a red sticky solid. After wash-
ing with n-hexane, the bright orange powder (70 mg, 90%) was
identified as 5 by NMR spectroscopy.
synthetic methods
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X-ray data collection, structure determination, and refine-
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4213–4216; Angew. Chem. 2009, 121, 4277–4280.
Crystallographic information for complexes 3–5 is summarized in
Table 1. Further details can be found in the Supporting Informa-
tion, which contains details of the crystallographic data collection
Table 1. X-ray data collection parameters for [Ar’Bi(ONC6H2-3,5-tBu2-4-
O)]2(m-O) (3) Ar’Bi(ONC6H2-3,5-tBu2-4-O)2 (4) and (Ph3CS)(Ar’)Bi(ONC6H2-3,5-
tBu2-4-O) (5).
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3
4
5
[8] Reactions of N2O3 with organometallic main-group complexes including
BiPh3 have been described, but no bismuth products were reported:
L. G. Makarova, K. A. Nesmeyanov, Zh. Obshch. Khim. 1939, 9, 771.
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empirical
formula
formula weight 1285.16
T [K] 143(2)
crystal system monoclinic
space group
a [ꢁ]
b [ꢁ]
C52H78Bi2N6O5 C40H59BiN4O4·CH3CN C45H54BiN3O2S·CH3CN
909.94
143(2)
triclinic
951.00
88(2)
monoclinic
P21/c
¯
P1
P21/c
9.8964(10)
34.851(3)
16.6025(16) 14.142(3)
90 93.614(3)
92.3244(14) 117.448(2)
13.398(3)
13.517(3)
22.1393(11)
9.2381(5)
22.8113(12)
90
110.1112(6)
90
c [ꢁ]
a [8]
b [8]
[13] a) T. W. Hayton, P. Legzdins, W. B. Sharp, Chem. Rev. 2002, 102, 935–991;
b) G. B. Richter-Addo, P. Legzdins, Metal Nitrosyls, Oxford University
Press: New York, 1992.
g [8]
90
97.173(3)
2233.9(9)
2
V [ꢁ3]
Z
5721.6(10)
4
4381.0(4)
4
[14] a) P. Legzdins, G. B. Richter-Addo, B. Wassink, F. W. B. Einstein, R. H.
Jones, A. C. Willis, J. Am. Chem. Soc. 1989, 111, 2097–2104; b) J. Chang,
M. D. Seidler, R. G. Bergman, J. Am. Chem. Soc. 1989, 111, 3258–3271;
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Melenkivitz, J. S. Southern, G. L. Hillhouse, T. E. Concolino, L. M. Liable-
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C. Chan, P.-K. Pat, T.-C. Lau, C.-Y. Wong, Organometallics 2011, 30, 1311–
1314.
1calcd [mgmꢀ3
]
1.492
6.189
1.353
3.988
1.442
4.113
m [mmꢀ1
]
R1[a] [I>2.0s(I)] 0.0326
wR2[a] (all data) 0.0832
0.0273
0.0631
0.0301
0.0710
2
[a] Definitions:
S[w(Fo2)2]]1/2
R1=Sj jFo jꢀjFc j j/SjFo j,
wR2=[S[w(Fo ꢀFc2)2]/
.
[15] D. R. Kindra, W. J. Evans, Dalton Trans. 2014, 43, 3052–3054.
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Trans. 2010, 39, 11277–11284.
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2008, 130, 15602–15610.
and refinement, along with selected bond lengths and angles.
CCDC-1012494 (3), CCDC-1012495 (4), and CCDC-1012496 (5) con-
tain the supplementary crystallographic data for this paper. These
data can be obtained free of charge from The Cambridge Crystallo-
graphic Data Centre via www.ccdc.cam.ac.uk/data_request/cif.
[19] A. P. Soran, C. Silvestru, H. J. Breunig, G. Balꢂzs, J. C. Green, Organome-
tallics 2007, 26, 1196–1203.
[20] S. S. Batsanov, Inorg. Mater. 2001, 37, 871–885.
[21] F. H. Allen, O. Kennard, D. G. Watson, L. Brammer, A. G. Orpen, R. Taylor,
J. Chem. Soc. Perkin Trans. 2 1987, 12, S1–S19.
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1513–1520.
Acknowledgements
We thank the Chemical Science, Geosciences, and Biosciences
Division of the Office of Basic Energy Sciences of the Depart-
ment of Energy (DE-SC0004739) for financial support of this
work. We also thank Ryan A. Zarkesh and Jordan F. Corbey for
assistance with X-ray crystallography.
[23] B. Wardle, Principles and Applications of Photochemistry, John Wiley &
Sons, Ltd, 2009.
Received: August 19, 2014
Published online on && &&, 0000
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FULL PAPER
The first example of NO insertion into
a BiꢀC bond has been found in the
direct reaction of NO with a Bi3+ com-
plex of the unusual (C6H2tBu2-3,5-O-4)2ꢀ
oxyaryl dianionic ligand, namely,
Ar’Bi(C6H2tBu2-3,5-O-4) [Ar’=2,6-
(Me2NCH2)2C6H3]. The oximate com-
plexes [Ar’Bi(ONC6H2-3,5-tBu2-4-O)]2(m-O)
and Ar’Bi(ONC6H2-3,5-tBu2-4-O)2 were
formed (see scheme), as well as (Ph3CS)-
(Ar’)Bi(ONC6H2-3,5-tBu2-4-O), by reaction
with Ph3CSNO.
&
Small-Molecule Activation
D. R. Kindra, I. J. Casely, J. W. Ziller,
W. J. Evans*
&& – &&
Nitric Oxide Insertion Reactivity with
the Bismuth–Carbon Bond: Formation
of the Oximate Anion, [ON=
(C6H2tBu2O)]1ꢀ, from the Oxyaryl
Dianion, (C6H2tBu2O)2ꢀ
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ꢀ 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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These are not the final page numbers! ÞÞ