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SHORT COMMUNICATION
Thus, the original Ru chloride precursor 5 used in the azido group during sample shipment). Its instability under ambient
2
conditions is attested by thermal gravimetric analysis (see Fig-
ure S6).
N atom transfer reaction seen here was successfully regener-
ated. We have therefore completed a synthetic cycle for the
conversion of PPh to [H NPPh ]Cl, as shown in Scheme 2. [H NPPh ]Cl: Compound 4 (10.08 mg, 0.01329 mmol), PPh
3
2
3
2
3
3
Compound 4 is formed from 5 by metathesis with sodium (recrystallized from hot ethanol) (9.92 mg, 0.1318 mmol), and
PPNCl (7.63 mg, 0.01329 mmol) (for use as an internal standard)
were combined with dry dichloromethane (100 mL) in a 100 mL
azide, and 4 may be photolyzed to yield the reactive nitrido
intermediate, compound 6. PPh traps 6 to presumably
3
yield the proposed intermediate 7,[ which reacts with HCl
13]
Schlenk tube. The headspace was evacuated, and the clear, dark-
purple mixture was photolyzed for two hours at room temperature
to yield a clear magenta product. Gaseous HCl was then bubbled
into the solution for 10 s, which subsequently turned pink. A 4 mL
aliquot was then removed, the solvent was removed in vacuo, and
(
g) to yield [H NPPh ]Cl and reform compound 5.
2 3
Conclusions
1
31
the residue was dissolved in CDCl
3
for analysis by H and
P
NMR spectroscopy. The remaining organic solution was set to
crystallize by slow diffusion with hexanes and yielded purple crys-
Through this study we report a novel Ru azido system
wherein photochemically induced N atom transfer is engi-
neered to be both intermolecular and quantifiable in the
2
tals of the [Ru
Yield (H NPPh
2
(chp)
4 2 2 2 2
Cl]·2CH Cl (5·2CH Cl ) starting material.
–1 31
2
3
Cl): 63%. MW: 313.76 gmol . P NMR (CDCl ):
3
formation of [H NPPh ]Cl from PPh . It should be noted
2
3
3
2 4 2 4
δ = 35.91 (s). Yield [{Ru (chp) Cl}]: 96% by UV/Vis. [Ru (chp) Cl]
that intermolecular reactivity of other late-transition-metal
nitrides is often hampered by nitride dimerization, which Cl] .
–1
+
MW: 751.71 gmol . MALDI-TOF: m/z = 751 [M] , 716 [M –
+
[
5,8d,14]
yields N2,
or perhaps reaction with solvent, as Basolo
Crystal Data for 4 at 100(1) K: C20
space group P2 /c, a = 10.8755(3) Å, b = 11.8291(3) Å, c =
9.2576(5) Å, β = 99.783(2)°, V = 2441.4(1) Å , Z = 4, ρcalcd. =
4 7 4 2
H12Cl N O Ru , monoclinic,
reported, by formation of chloroamines through reaction of
1
electrophilic nitrenes with chloride in solution.[ We sug-
15]
3
1
–
3
–1
gest that such an alternate pathway may be responsible for 2.063 gcm , μ = 1.720 mm , Bruker Quazar SMART APEX II
the decreased yield of [H NPPh ]Cl produced through this diffractometer, λ (Mo-K
α
) = 0.71073 Å. A total of 114575 reflec-
cycle. On-going efforts to increase this yield include altering tions were collected in the 2θ range of 1.90–30.10°, 6521 being
2
3
unique (Rint = 0.0477). An analytical absorption correction was
applied on the basis of the intensities of equivalent reflections (Tmin
the workup methodology as well as designing new support-
ing ligands and exploring a larger substrate scope. This
=
0.5462, Tmax = 0.7248). Least-squares refinement on 334 param-
eters converged normally with R1 [IϾ2σ(I)] = 0.0237, wR2 =
.0570, GOF = 1.023.
work completes the first synthetic cycle for intermolecular
N atom transfer with a Ru N species and implicates Ru N
2
2
0
as a reactive species with potential for other intermolecular
N atom transfer reactions.
2 2 5 4 4 2
Crystal Data for 5·2CH Cl at 100(1) K: C20H12Cl N O Ru , or-
thorhombic, space group Pbca, a = 19.535(4) Å, b = 12.827(3) Å,
3
–3
c = 24.586(5) Å, V = 6161(2) Å , Z = 8, ρcalcd. = 1.621 gcm , μ =
–
1
1
.443 mm , Bruker Quazar SMART APEX II diffractometer, λ
Experimental Section
(
Mo-K ) = 0.71073 Å. A total of 109497 reflections were collected
α
in the 2θ range of 1.657–27.164°, 6823 being unique (Rint = 0.0393).
An analytical absorption correction was applied on the basis of the
intensities of equivalent reflections (Tmin = 0.6939, Tmax = 0.8408).
Least-squares refinement on 316 parameters converged normally
with R1 [IϾ2σ(I)] = 0.0393, wR2 = 0.0934, GOF = 1.189. The
unit cell contains 16 dichloromethane molecules, which have been
treated as a diffuse contribution to the overall scattering without
specific atom positions by SQUEEZE/PLATON.[
Synthetic Methods: All syntheses were conducted under a dry N
atmosphere using Schlenk line techniques; product workup and iso-
lation were achieved under ambient conditions. Dichloromethane
2
2
and methanol were dried with CaH and MgO, respectively, and
distilled before use. Toluene, hexanes, and diethyl ether were ob-
tained from a Vacuum Atmospheres Solvent System and degassed
prior to use. All materials were commercially available and used
as received, unless otherwise noted. Compound 5 was prepared as
described in the Supporting Information. Photolysis of both frozen
and room-temperature samples of 4 was performed in a Rayonet
RPR-200 photochemical reactor with light from 350 nm mercury
vapor lamps.
16]
2 2
CCDC-922812 (for 4) and -922813 (for 5·CH Cl ) contain the sup-
plementary crystallographic data for this paper. These data can be
obtained free of charge from The Cambridge Crystallographic
Data Centre via www.ccdc.cam.ac.uk/data_request/cif.
[
Ru
2
(Chp)
4 3 2 4
N ] (4): [Ru (chp) Cl] (315.25 mg, 0.419 mmol) and
Supporting Information (see footnote on the first page of this arti-
cle): EPR spectra and simulations of 4 and 6, P NMR of
NaN
3
(2.72 g, 41.85 mmol) were added to a 200 mL Schlenk flask
31
along with a mixture of dry dichloromethane (100 mL) and anhy-
drous methanol (12 mL) and stirred for 96 h under static, dry nitro-
gen. The suspension was then filtered through a fine frit, the sol-
vent in the filtrate was removed in vacuo, and the product was
washed with diethyl ether and hexanes and collected (280 mg,
2 3
[H NPPh ]Cl product formation before and after doping with au-
thentic sample, thermal ellipsoid plot of 5, TGA data for 4, UV/
Vis data for 5, selected bond lengths and angles for 4 and 5, and
improved methodology for the original synthesis of 5.
–1
+
3
88%). MW: 758.25 gmol . MALDI-TOF: m/z: = 716 [M – N ] .
IR (ATR): ν˜ = 3092 (w), 2028 [s (N
3
)], 1608 (m), 1593 (s), 1529 (s), Acknowledgments
1
9
437 (s), 1429 (m), 1387 (m), 1345 (s), 1324 (w), 1231 (m), 1014 (s),
–
1
31 (w), 920 (w), 795 (m), 787 (m), 668 (s) cm . We thank the U.S. Department of Energy, Chemical Sciences, Geo-
[
C
20
H
12
N
7
Cl
4
O
4
Ru
2
]·2CH
2
Cl
2
: calcd. C 28.47, H 1.74, N 10.56;
sciences, and Biosciences Division, Office of Basic Energy Sciences,
Office of Science (DE-FG02-10ER16204) and the Petroleum Re-
search Fund (50690-ND3) for their support of this work. A. R. C.
found C 28.74, H 1.69, N 9.93 (the N content is routinely low for
samples of 4, which we attribute to partial decomposition of the
Eur. J. Inorg. Chem. 2013, 3808–3811
3810
© 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim