Reactivity of 4-nitrosoanilines towards dimeric halogenido-bridged complexes of iridium(iii) and rhodium(iii) of the type [(h5- C5Me5)MX2]2

Article abstract of DOI:10.5560/ZNB.2012-0144

The synthesis, spectroscopic characterization and crystal structures of new C-nitrosoaryl complexes of iridium(III) and rhodium(III) are reported. The reactions of the m2-halogenido-bridged dimers [(h5-C5Me5)IrX2]2 [X = Cl (1a), Br (1b), I (1c)] and [(h5-C5Me5)RhCl2]2 (2a) with N,N-dimethyl- (3) and N,N-diethyl-4-nitrosoaniline (4) yield the mononuclear complexes [(h5- C5Me5)MX2(3)] [M = Ir, X = Cl (5a), Br (5b), I (5c);M= Rh, X = Cl (7a)] and [(h5-C5Me5)MX2(4)] [M = Ir, X = Cl (6a), Br (6b), I (6c); M = Rh, X = Cl (8a)]. All new compounds were characterized by their melting points, NMR, IR and mass spectra as well as in selected cases by UV/Vis spectroscopy. The X-ray structure analyses revealed a slightly distorted pseudo-octahedral configuration ( three-legged pianostool ) and s-N coordination of the C-nitroso ligand.

Full text of DOI:10.5560/ZNB.2012-0144

Reactivity of 4-Nitrosoanilines Towards Dimeric Halogenido-bridged
Complexes of Iridium(III) and Rhodium(III) of the Type [(η5-
C5Me5)MX2]2
Stefan Wirth and Ingo-Peter Lorenz
Department of Chemistry, Ludwig-Maximilian-University Munich, Butenandtstraße 5-13 (House
D), D-81377 Munich, Germany
Reprint requests to Prof. Dr. I.-P. Lorenz. E-mail: ipl@cup.uni-muenchen.de
Z. Naturforsch. 2012, 67b, 532 – 542 / DOI: 10.5560/ZNB.2012-0144
Received May 25, 2012
Dedicated to Professor Wolfgang Beck on the occasion of his 80th birthday
The synthesis, spectroscopic characterization and crystal structures of new C-nitrosoaryl com-
plexes of iridium(III) and rhodium(III) are reported. The reactions of the µ2-halogenido-bridged
dimers [(η5-C5Me5)IrX2]2 [X = Cl (1a), Br (1b), I (1c)] and [(η5-C5Me5)RhCl2]2 (2a) with
N,N-dimethyl- (3) and N,N-diethyl-4-nitrosoaniline (4) yield the mononuclear complexes [(η5-
C5Me5)MX2(3)] [M = Ir, X = Cl (5a), Br (5b), I (5c); M = Rh, X = Cl (7a)] and [(η5-C5Me5)MX2(4)]
[M = Ir, X = Cl (6a), Br (6b), I (6c); M = Rh, X = Cl (8a)]. All new compounds were characterized
by their melting points, NMR, IR and mass spectra as well as in selected cases by UV/Vis spec-
troscopy. The X-ray structure analyses revealed a slightly distorted pseudo-octahedral configuration
(“three-legged pianostool”) and σ-N coordination of the C-nitroso ligand.
Key words: C-Nitroso Anilines, N Ligand, Iridium, Rhodium
Introduction
Aromatic compounds containing a C-nitroso group
processes [15 – 23], their significance is also affirmed
in biochemistry.
This article now is concerned with the coordina-
have been known for over 130 years. The first ex- tion of N,N-dimethyl-4-nitrosoaniline (3) and N,N-
amples were already published in 1874 by A. von diethyl-4-nitrosoaniline (4) to Ir(III) and Rh(III) com-
Bayer [1 – 3]. However, coordination to metal centers plexes. These aromatic C-nitroso compounds show
was not reported before 1907 [4]. Since these early at- remarkably high reactivity because the amino group
tempts various synthetic routes to high-yield prepara- in para-position increases the electron density at the
tions of C-nitroso compounds were developed [5, 6]. NO function [24]. Complexes containing these ligands
Current reviews show the constant interest in this field are known for different metal centers and coordina-
of research during the last decades [7]. Not only due tion modes as published by our group [25, 26] and
to its rich coordination chemistry with eleven different others [8, 9]. However, examples for these or compa-
main coordination modes to metal centers [8, 9], the rable aromatic C-nitroso ligands coordinated to Ir or
family of C-nitroso compounds has been investigated Rh centers are rare in literature [27 – 39]. Besides our
extensively. Also the possible applications in organic own results [36], the available crystallographic data
synthesis [10], for example the nitroso ene [11] or ni- for monodentate σ-N-coordination is limited to only
troso Diels-Alder reaction [12 – 14] attracted attention. two Rh(I) complexes [30, 32]. In fact, the new com-
The most important properties of the NO function for plexes presented in the following are the results of pre-
these applications are the high reactivity based upon liminary research to our recently published work on
the polarization of the N–O bond and the specific struc- 1,4-bis(4-nitrosophenyl)piperazine as a bridging lig-
ture in the equilibrium between nitroso monomer and and [36] and are the only further examples for crys-
azodioxy dimer which leads to a unique chemo- and tallographically characterized Ir(III) and Rh(III) com-
regioselectivity [10]. Since the discovery of the impor- plexes containing monodentate σ-N-coordinated aro-
tant roles of C-nitroso derivatives in various biological matic C-nitroso ligands.
c
ꢀ 2012 Verlag der Zeitschrift fu¨r Naturforschung, Tu¨bingen · http://znaturforsch.com
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Scheme 1. Synthesis of the new iridium(III) (5a–c, 6a–c) and rhodium(III) (7a, 8a) complexes with 3 or 4 as ligands.
Results and Discussion
matic ring are observed relatively broad; in particular
for the protons in ortho-position of the nitroso group
The new mononuclear complexes [(η5- (H3, H5; 7.91 – 9.02 ppm) they are stretched at room
C5Me5)MX2(3)] [M = Ir, X = Cl (5a), Br (5b), I temperature over a range of nearly 1.0 ppm. “Freez-
(5c); M = Rh, X = Cl (7a)] and [(η5-C5Me5)MX2(4)] ing” the rotation by a measurement at −60 ◦C leads to
[M = Ir, X = Cl (6a), Br (6b), I (6c); M = Rh, X a significant splitting of the broad signal (5c: 7.24 and
= Cl (8a)] are obtained as illustrated in Scheme 1. 9.01 ppm; ∆ = 1.77 ppm) as depicted for 5c in Fig. 1
Addition of excess N,N-dimethyl-4-nitrosoaniline (A, B). This splitting is induced by the large magnetic
(3) or N,N-diethyl-4-nitrosoaniline (4) to the µ2- anisotropy of the NO group and known for aromatic
halogenido-bridged Ir(III) (1a-c) or Rh(III) (2a) nitroso compounds [40, 41]. The peak at 9.01 ppm is
dimers in Et2O or CH2Cl2, respectively, leads to their clearly ascribed to the “anti-position” of the nitroso-
nucleophilic cleavage and yields the monosubstituted O atom (H5) because of the strong deshielding ef-
products. These are obtained as red (5a, 6a, 7a, 8a) or fect of the functional group for this proton [41]. Sim-
green (5b, 5c, 6b, 6c) microcrystalline solids and are ilar effects appear in the 13C NMR spectra of 5a–8a.
stable when exposed to air. They show good solubility The carbons in ortho-position of the nitroso group
for instance in dichloromethane or chloroform and are (C3, C5; about 132 ppm) are observed as extremely
insoluble in n-pentane.
broad signals for the iridium(III) complexes (5a–c, 6a–
Mass spectra of the iridium(III) complexes 5a–c and c) and are not detectable for the rhodium(III) com-
6a–c in (+)-FAB mode exhibit the parent peak [M]+ pounds (7a, 8a). Again, in low temperature measure-
as well as a similar fragmentation resulting from the ments (−60 ◦C) this very broad signal splits (5c: 122.6
loss of the halogenido and nitroso ligands. Mass spec- and 140.9 ppm; ∆ = 18.3 ppm), and additionally even
tra ((+)-FAB mode) of the rhodium(III) compounds 7a the peaks for C2 and C6 are separated (5c: 108.1 and
and 8a lack the [M]+ peak, but show also the typical 112.2 ppm; ∆ = 4.1 ppm) (Fig. 1: C, D). In both cases
fragmentation pattern starting with [M-Cl]+.
the signal found at lower field of each pair is ascribed
1
In the H NMR spectra of 5a–8a the N-alkyl sub- to the deshielded anti-position to N = O [41]. Assign-
stituents are detected at the same positions as measured ment of the peak in the range of 162.7 – 164.5 ppm to
for the uncoordinated ligands (N-Me: 3.14(s) ppm; C4 (ON-Cq) and the one at about 155 ppm to C1 (N-
N-Et: 1.26 (t), 3.47(q) ppm). The signal of the Cp- Cq) was done according to Gowenlock et al. [42 – 44].
methyl groups of 5a–8a is located in the range All other carbon signals are observed within the ex-
of 1.52 – 1.82 ppm and shows a weak coordination- pected ranges.
induced shift (0.05 – 0.10 ppm) to higher field com-
In the IR spectra of 5a–8a weak ν(C-H) absorp-
pared to the starting complexes 1a–2a. Due to rotation tions are detected in the range of 3100 – 2800 cm−1 for
about the N2–C4 bond the proton signals of the aro- all complexes. Within the fingerprint area (wavenum-
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S. Wirth – I.-P. Lorenz · Reactivity of 4-Nitrosoanilines Towards Dimeric Halogenido-bridged Complexes
Table 1. UV/Vis absorption data of the ligands 3 and 4 and
the complexes 5a, 5b and 6a in CH2Cl2: λmax (in nm), ε (in
L mol−1 cm−1) in parentheses.
λmax1
λmax2
λmax3
3
273 (6000)
271 (5400)
273 (8000)
274 (6300)
270 (6500)
420 (31 300)
420 (11 800)
419 (21 900)
424 (32 600)
425 (15 400)
−
5a
5b
4
509a (19 000)
516a (15 300)
−
6a
512a (21 400)
a
Weak shoulder at about 650 nm with no distinct maximum.
and (1380 cm−1 [46]; own equipment: CH2Cl2:
1377 cm−1; ATR: 1370 cm−1). The ν( N = O) band is
found in the range of 1380 – 1369 cm−1 in CH2Cl2 so-
lution and within 1366 – 1356 cm−1 for ATR measure-
ment. This only small decrease in wavenumbers lies in
the expected range for σ-N coordination of C-nitroso
compounds [9, 47].
On account of the intense red color of the prod-
ucts in solution, UV/Vis spectra of 5a, 5b and 6a
in dichloromethane were recorded (Table 1). Two of
the absorptions are already observed in the ligand
spectra and show no significant shift in wavelength.
λmax1 is ascribed to a π-π∗ absorption of the ni-
troso aniline and keeps its intensity after coordina-
tion. By contrast, λmax2 looses intensity, as it originates
from an intramolecular CT absorption of this “push-
pull” ligand. The third band is tentatively ascribed
to a ligand-to-metal CT absorption of the type [ON-
Ir/RhIII] (Ir/RhIII is low-spin t2g6) and shows a weak
shoulder at about 650 nm (most likely n-π∗) with no
distinct maximum.
Single crystals suitable for X-ray diffraction anal-
ysis were obtained by slow isothermic diffusion of
n-pentane into solutions of the complexes in chloro-
form (5a, 6a, 6b, 7a, 8a) or dichloromethane (5c,
6c). Selected bond lengths and angles are listed and
compared with those of ligands 3 [48] and 4 [46]
in Table 2. Crystallographic data and details of the
structure refinements are summarized in Table 3. Only
Fig. 1. Significant areas of the 1H NMR (a: CDCl3, b:
CD2Cl2) and 13C NMR spectra (c: CDCl3, d: CD2Cl2) of
5c at room temperature (a, c) and at −60 ◦C (b, d).
bers smaller than 1604 cm−1) the ν( N = O) absorp- two of the complexes are depicted as examples with
tions are assigned according to the literature value atom numbering in Figures 2 (6a) and 3 (7a). The
of 3 (1363 cm−1 [9, 45]; own equipment: CH2Cl2: coordination sphere (“three-legged pianostool”) of
1365 cm−1; ATR: 1362 cm−1) to bands in the range each metal center consists of one pentamethyl-η5-
of 1367 – 1361 cm−1 for 5a–c and 7a. For the com- cyclopentadienyl, two terminal halogenido ligands and
plexes containing N,N-diethyl-4-nitrosoaniline (6a– the σ-N-coordinated nitroso ligand. The M–X bond
c, 8a) only a slight shift of the ν( N = O) ab- lengths in 5a–8a are slightly longer than those found
sorption to lower frequencies is observed com- for the terminal halogenido ligands in the starting
˚
˚
pared to literature data for the uncoordinated lig- complexes (1a: 2.387(4) A [49]; 1b: 2.5195(2) A [50];
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˚
Table 2. Selected bond lengths (A) and angles (deg) of the ligands 3 [48] and 4 [46] and the complexes 5a, 5c, 6a–c, 7a and
8a.
Bond lengths
M-X1
M-X2
M-N2
O1-N2
N2-C4
N1-C1
C2-C3
C5-C6
C1-C2
C3-C4
3a,b,c
−
−
−
−
−
−
−
−
−
−
1.131
1.121
1.212
1.292
1.255(4)
1.248(4)
1.390
1.390
1.445
1.365
1.365
1.322
1.370
1.325
1.357
1.325
1.370
1.352
1.434
1.394
1.387
1.425
1.362
1.380
1.402
−
−
1.445
1.322
1.352
1.357
1.444
5a
5c
7a
4a
2.3952(1) 2.4121(1)
2.7143(2) 2.7018(4)
2.073(3)
2.069(2)
1.391(2)
1.385(3)
1.390(3)
1.438d
1.347(2)
1.342(3)
1.340(3)
1.358(4)
1.345(4)
1.355(4)
1.348(2)
1.354(4)
1.341(6)
1.354(2)
1.366(9)
1.363(3)
1.376(2)
1.372(2)
1.356(2)
1.350(2)
1.356(3)
1.365(4)
1.357(6)
1.369(9)
1.366(3)
1.375(2)
1.360(2)
1.367(2)
1.369(2)
1.368(4)
1.348(4)
1.418(2)
1.446(9)
1.428(3)
1.420(2)
1.425(2)
1.418(2)
1.426(2)
1.432(3)
1.420(4)
1.424(2)
1.401(3)
1.411(3)
1.386(2)
1.393(2)
1.407(2)
1.419(2)
1.403(3)
1.399(4)
1.378(5)
2.3980(6) 2.4172(6) 2.1069(18) 1.250(2)
−
−
−
1.253d
1.215d
1.246(4)
1.252(4)
1.263(6)
1.254(2)
1.243(1)
−
−
−
1.458d
6aa
2.3989(1) 2.4099(1)
2.4026(1) 2.4145(1)
2.5307(4) 2.5267(4)
2.7061(4) 2.7026(4)
2.068(3)
2.087(3)
2.054(2)
2.058(4)
1.391(2)
1.385(4)
1.382(4)
1.388(6)
6b
6c
8a
2.5328(13) 2.5275(12) 2.086(3)
1.363(11) 1.346(12) 1.404(13) 1.339(12) 1.419(13)
Angles
Torsion angles
X1-M-X2
N2-M-X1
N2-M-X2
O1-N2-M
O1-N2-C4 N2-C4-C3
C1-N1-C7 O1-N2-C4-C3 C7-N1-C1-C6
3a,b,e
−
−
−
−
−
−
−
−
126.2
115.2
116.5
125.2
123.1
117.6
121.5
125.3
121.9(3)
121.0(6)
−
−
−
−
−
−
−
−
116.4
121.3
−
−
−
−
−
−
116.2
120.2
−
−
5a
5c
87.57(4)
90.369(5)
89.71(2)
−
87.03(9)
88.81(14)
87.99(2)
−
94.85(9)
91.84(14)
96.36(2)
−
116.5(2)
117.9(4)
116.1(3)
114.7(2)
120.6(3)
120.8(2)
5.5(2)
2.0(9)
4.1(3)
−0.25
−2.45
8.7(2)
−7.4
−7.4
−10.5
−11.4
0.8(6)
−1.7
0.4(3)
−4.67
3.69
7a
115.44(13) 116.01(17) 121.15(19) 121.48(19)
4a,d
−
110.85
109.87
128.64
128.79
122.66
121.25
−
−
−
−
6aa
85.07(4)
85.87(4)
88.53(3)
89.367(14)
88.58(2)
85.88(9)
86.26(3)
86.53(13)
87.26(11)
85.4(2)
92.13(9)
92.56(3)
88.53(3)
94.28(12)
92.8(2)
116.4(2)
115.5(2)
116.4(4)
116.8(3)
115.7(6)
115.8(3)
115.7(3)
115.0(2)
115.4(4)
115.9(3)
120.9(3)
120.9(3)
121.0(2)
120.9(4)
120.8(9)
121.8(3)
121.4(4)
122.4(2)
122.1(4)
121.2(9)
1.5(6)
11.8(6)
2.9(9)
2.8(3)
6.8(5)
6b
6c
8a
a
Two molecular units in the unit cell. Column headings derived from the “first” fragment; from the “second” comparable data are given;
b
c
d
˚
disorder of the nitroso group; estimated standard deviations: 0.008–0.015 A; data obtained from the CCDC, standard deviations not
available; e estimated standard deviations: 0.5 – 1.0◦.
˚
˚
˚
1c: 2.694(1) A [50]; 2a: 2.397(2) A [51]). All angles for ligand 3 (Rh–N 2.050(4) A) [32] or 1-bromo-4-
˚
enclosed by the halogenido ligands or by one halo- nitrosobenzene (Rh–N 1.958(3) A) [30] at Rh(I) cen-
genido and the nitroso ligand differ only by a few ters. Again the Rh–N bond lengths observed in 7a
degrees from 90◦ (Table 2; only exception 7a: N2– (2.1069(18) A) and 8a (2.086(3) A) are slightly longer
M–X2) and prove the only slight distortion of the and in good accordance to our results for 1,4-bis(4-
˚
˚
˚
pseudo-octahedral geometry. The Ir–N bonds observed nitrosophenyl)piperazin (2.097(2) A) [36]. Thus, the
in 5a, 5c and 6a–c are in the range 2.054(2)-2.087(3) A M–N bond lengths found in 5a–8a are close to those
˚
and therefore somewhat longer than reported for observed in Rh(III) or Ir(III) complexes with biden-
1-chloro-2-nitroso-1,2-dihydrodicyclopentadiene σ-N tate sp2-N-donor ligands [53 – 57]. Due to the limited
˚
coordinated to Ir(III) (1.948(6) A) [52], but simi- quality of the structural data of ligand 3 the obtained
lar to that of our own recently published dinuclear complexes are better compared with ligand 4 (although
˚
Ir(III) complexes (2.061(4)-2.088(3) A) [36]. Crystal- both ligand data sets are listed in Table 2). A compari-
lographic data for C-nitroso ligands with σ-N co- son shows that there are only minor structural changes
ordination to Rh(III) are not available from other within the ligands after coordination. The N = O bond
groups. Structure determinations are only known length is only marginally increased, and the quinoid
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S. Wirth – I.-P. Lorenz · Reactivity of 4-Nitrosoanilines Towards Dimeric Halogenido-bridged Complexes
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Fig. 2. Molecular structure of the irid-
ium(III) complex 6a with hydrogen bonds
(dashed) to the next solvent molecules.
The displacement ellipsoids are drawn
at the 50% probability level. Hydro-
gen atoms (except CHCl3) are omitted
for clarity. Hydrogen bond data: C(41)–
H(41)···Cl(4): d(D–H) 0.99(6), d(H···A)
2.47(4), d(D···A) 3.427(2), <(D–H–A)
162 (2)◦; C(42)–H(42)···Cl(2)#1: d(D–
H) 1.08(2), d(H···A) 2.38(2), d(D···A)
3.456(2), <(D–H–A) 175 (4)◦; symmetry
operator: #1 x, −y+1/2, z+1/2.
contribution to the aromatic ring is stronger. This is in-
dicated by shorter N2–C4 and C2–C3 bonds and elon-
gated C3–C4 bond lengths (Table 2). In all new com-
plexes the NO function as well as the alkyl groups are
located within the phenyl plane with only small de-
viations. It should be mentioned that the ethyl groups
show the sterically preferred trans-configuration in un-
coordinated 4 and in 6b, 6c and 8a. In the crystal
structure of 6a embedded CHCl3 leads to a relatively
small intermolecular distance and cis-configuration of
the ethyl groups of one of the two complex molecules
in the asymmetric unit (Fig. 2).
Conclusion
In this paper we have presented the synthesis, spec-
troscopic properties and X-ray structures of new irid-
ium(III) and rhodium(III) complexes containing N,N- Fig. 3. Molecular structure of the rhodium(III) complex 7a.
The displacement ellipsoids are drawn at the 50% probability
level. Hydrogen atoms are omitted for clarity.
dialkyl-4-nitrosoanilines (alkyl = methyl, ethyl) as
monodentate σ-N ligands. NMR studies indicate that
the well known NO rotation for C-nitroso compounds
persists for these complexes in solution at room tem- spectroscopic properties and the high reactivity of
perature, although the crystallographic characteriza- these ligands induced by the amino group in para-
tion proves that the quinoid contribution to the aro- position to the NO function makes them promising
matic ring of both N,N-dialkyl-4-nitrosoanilines is candidates for the cleavage of many other halogenido
even increased after coordination. These interesting or analogously bridged transition metal complexes.
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S. Wirth – I.-P. Lorenz · Reactivity of 4-Nitrosoanilines Towards Dimeric Halogenido-bridged Complexes
Experimental
crystals (platelets) were obtained by slow isothermic
diffusion of n-pentane into a solution of 5a in CHCl3. M. p.
decomp. > 206 ◦C. – UV/Vis (CH2Cl2): λmax (ε) = 271
(5400), 420 (11 800), 509 nm (19 000 L mol−1 cm−1). –
General
All experiments for the preparation of the new complexes
were performed under dry argon atmosphere using Schlenk
and vacuum-line techniques. The starting complexes [(η5-
C5Me5)IrX2]2 (X = Cl (1a) [58], Br (1b) [59], I (1c) [60])
and [(η5-C5Me5)RhCl2]2 (2a) [60] were prepared according
to literature methods. N,N-Dimethyl-4-nitrosoaniline (3) and
N,N-diethyl-4-nitrosoaniline (4) were commercially avail-
able and used as purchased. Solvents were purified by stan-
dard procedures; dichloromethane was distilled from calcium
hydride, diethyl ether from sodium pieces and n-pentane
from lithium aluminum hydride. Chloroform was dried dy-
IR (CH2Cl2): ν = 3051 (w), 2980 (w), 2924 (w), 2864
(w), 1601 (vs), 1554 (w), 1536 (w), 1442 (w), 1395 (w),
1382 (w), 1367 ν( N = O) (m), 1338 (m), 1310 (m), 1247
(m), 1137 (vs), 1029 (m), 989 (w), 940 (w), 877 (w), 827
(m), 632 (w), 611 (m), 592 (w) cm−1. – IR (ATR, solid):
ν = 3047 (w), 2985 (w), 2962 (w), 2918 (w), 2853 (w),
1596 (s), 1536 (w), 1479 (w), 1445 (w), 1393 (w), 1383(w),
1362 ν( N = O) (w), 1332 (s), 1308 (s), 1245 (s), 1224 (w),
1129 (vs), 1082 (w), 1034 (m), 1022 (m), 989 (w), 935 (w),
872 (m), 831 (s), 792 (w), 737 (s), 628 (w), 608 (m), 590 (m)
cm−1. – 1H NMR (399.78 MHz, CDCl3): δ = 1.52 (s, 15 H,
Cp-CH3), 3.14 (s, 6 H, N-CH3), 6.53 (d, 2 H, 3J = 9.67 Hz,
CHarom/H2+H6), 8.26 (br, 2 H, CHarom/H3+H5). –
13C NMR (100.53 MHz, CDCl3): δ = 9.0 (Cp-CH3), 41.2
(N-CH3), 88.1 (Cp-Cq), 111.0 (CHarom/C2+C6), 131.8 (br,
CHarom/C3+C5), 156.5 (N-Cq/C1), 164.0 (ON-Cq/C4).
– MS ((+)-FAB): m/z (%) = 549.8 (4) [M]+, 513.5 (28)
˚
namically in a column with 3 A molecular sieves. All dried
solvents were stored under dry argon atmosphere with 3 A
molecular sieves (chloroform, dichloromethane) or sodium
pieces (diethyl ether, n-pentane).
˚
Melting points were determined using a Bu¨chi Melting-
Point B-540 apparatus and are uncorrected. UV/Vis data
were recorded with a Perkin Elmer Lambda 16 instrument
in CH2Cl2 in the range of 250 – 800 nm. IR spectra were
measured in the range of 4000 – 400 cm−1; in solution with
a Perkin Elmer Spectrum One FT-IR spectrometer and in the
solid state using a Jasco FT/IR-460Plus instrument equipped
with MIRacleTM ATR (diamond cell) from PIKE Technolo-
gies. NMR spectra were obtained with Jeol Ecplise 270, Jeol
Ecplise 400 and Jeol EX 400 spectrometers at ambient tem-
perature unless stated otherwise. All chemical shifts δ are
given in parts per million (ppm) relative to TMS. Mass spec-
tra were obtained with a Jeol MStation JMS-700 in (+)-
FAB mode with NBA (3-nitrobenzyl alcohol) matrix. Multi-
isotopic fragments are referred to the isotope with the high-
est abundance. Elemental analyses were performed by the
Microanalytical Laboratory of the Department of Chemistry
using a Heareus elementar varioEL instrument.
[M-Cl]+, 363.4 (100) [M-Cl-3]+.
– C18H25Cl2IrN2O
(548.53): calcd. C 39.41, H 4.59, N 5.11; found C 39.04, H
4.46, N 4.92.
(4-Nitroso-N,N-dimethylaniline-N)dibromido(pentamethyl-
η5-cyclopentadienyl)iridium(III) (5b)
Reagents:
145 mg
(0.149 mmol)
1b,
134 mg
(0.894 mmol) 3. Reaction time: 2 h. Yield: 123 mg
(0.193 mmol, 65%) dark-green microcrystalline solid. M. p.
decomp. > 202 ◦C. – UV/Vis (CH2Cl2): λmax (ε) = 273
(8000), 419 (21 900), 516 nm (15 300 L mol−1 cm−1). – IR
(CH2Cl2): ν = 3051 (w), 2978 (w), 2921 (w), 2864 (w),
1601 (vs), 1556 (w), 1537 (m), 1442 (w), 1394 (w), 1383
(w), 1367 ν( N = O) (m), 1337 (m), 1310 (m), 1245 (m),
1135 (vs), 1029 (m), 989 (w), 940 (w), 877 (m), 827 (m), 632
(w), 611 (m), 594 (w) cm−1. – IR (ATR, solid): ν = 3055
(w), 2984 (w), 2962 (w), 2915 (w), 2854 (w), 1595 (s), 1542
(w), 1534 (w), 1483 (w), 1444 (w), 1393 (w), 1380(w), 1361
ν( N = O) (w), 1331 (s), 1307 (s), 1242 (s), 1226 (w), 1123
(vs), 1079 (w), 1032 (w), 1019 (m), 989 (w), 937 (m), 871
(m), 828 (s), 792 (w), 738 (s), 629 (m), 609 (m), 589 (m)
cm−1. – 1H NMR (399.78 MHz, CDCl3): δ = 1.58 (s, 15 H,
Cp-CH3), 3.14 (s, 6 H, N-CH3), 6.54 (d, 2 H, 3J = 9.35 Hz,
CHarom/H2+H6), 8.24 (br, 2 H, CHarom/H3+H5). –
13C NMR (100.53 MHz, CDCl3): δ = 9.4 (Cp-CH3), 41.1
(N-CH3), 89.0 (Cp-Cq), 110.7 (CHarom/C2+C6), 132.0 (br,
CHarom/C3+C5), 156.3 (N-Cq/C1), 164.5 (ON-Cq/C4).
– MS ((+)-FAB): m/z (%) = 636.9 (9) [M]+, 557.0 (86)
Synthesis of the iridium(III) complexes 5a–c and 6a–c
The dimers [(η5-C5Me5)IrX2]2 [ X = Cl (1a), Br (1b),
I (1c)] and six equivalents of ligand 3 or 4 were dissolved
in 50 mL of dry Et2O and stirred at room temperature. The
solvent showed a dark-red color instantly. After the reaction
was completed (see time below) the precipitate was filtered
off and washed with dry Et2O several times (till the filtrate
is nearly colorless) to remove excess ligand. The resulting
product was dried in vacuo for 12 h at 50 ◦C.
(4-Nitroso-N,N-dimethylaniline-N)dichlorido(pentamethyl-
η5-cyclopentadienyl)iridium(III) (5a)
Reagents:
122 mg
(0.153 mmol)
1a,
138 mg [M-Br]+, 477.1 (24) [M-2Br]+, 407.1 (100) [M-Br-3]+. –
(0.918 mmol) 3. Reaction time: 3 h. Yield: 162 mg C18H25Br2IrN2O(637.43): calcd. C 33.92, H 3.95, N 4.39;
(0.295 mmol, 96%) dark-red microcrystalline solid. Black found C 34.33, H 3.98, N 4.45.
Unauthenticated
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S. Wirth – I.-P. Lorenz · Reactivity of 4-Nitrosoanilines Towards Dimeric Halogenido-bridged Complexes
539
(4-Nitroso-N,N-dimethylaniline-N)diiodido(pentamethyl-
(w), 1366 ν( N = O) (w), 1326 (s), 1305 (s), 1246 (s), 1187
(w), 1166 (w), 1127 (vs), 1073 (s), 1029 (s), 1009 (m),
955 (w), 930 (w), 872 (m), 832 (m), 794 (w), 755 (w),
η5-cyclopentadienyl)iridium(III) (5c)
Reagents:
216 mg
(0.186 mmol)
1c,
168 mg
1
716 (s), 627 (w), 605 (m) cm−1. – H NMR (270.17 MHz,
(1.116 mmol) 3. Reaction time: 5 h. Yield: 246 mg
(0.336 mmol, 90%) dark-green microcrystalline solid.
Red crystals (platelets) were obtained by slow isothermic
diffusion of n-pentane into a solution of 5c in CH2Cl2. M. p.
decomp. > 182 ◦C. – IR (CH2Cl2): ν = 3044 (w), 2975 (w),
2916 (w), 2864 (w), 1600 (vs), 1557 (w), 1532 (m), 1443
(w), 1393 (w), 1382 (w), 1366 ν( N = O) (m), 1338 (m),
1308 (m), 1240 (m), 1126 (vs), 1027 (m), 960 (w), 941 (w),
876 (w), 826 (m), 632 (w), 610 (m), 594 (w) cm−1. – IR
(ATR, solid): ν = 3069 (w), 2986 (w), 2954 (w), 2910 (w),
2851 (w), 1594 (s), 1541 (w), 1534 (w), 1484 (w), 1439 (w),
1391 (m), 1377 (w), 1361 ν( N = O) (w), 1329 (s), 1305 (s),
1229 (s), 1222 (w), 1121 (vs), 1074 (w), 1024 (m), 1017 (m),
988 (w), 936 (m), 873 (m), 824 (s), 789 (w), 736 (s), 628 (m),
614 (m), 608 (m), 594 (m) cm−1. – 1H NMR (399.78 MHz,
CDCl3): δ = 1.72 (s, 6 H, Cp-CH3), 1.82 (s, 9 H, Cp-CH3),
3.15 (s, 6 H, N-CH3), 6.61 (br, 2 H, CHarom/H2+H6),
8.18 (br, 2 H, CHarom/H3+H5). – 1H NMR (400.18 MHz,
CD2Cl2, −60 ◦C): δ = 1.62 (s, 15 H, Cp-CH3), 3.11
(s, 6 H, N-CH3), 6.54 (br, 2 H, CHarom/H2+H6), 7.24
(br, 1 H, CHarom/H3), 9.01 (br, 1 H, CHarom/H5). –
13C NMR (100.53 MHz, CDCl3): δ = 10.5 (Cp-CH3), 10.9
(Cp-CH3), 40.8 (N-CH3), 89.0 (Cp-Cq), 90.3 (Cq, arom),
110.3 (CHarom/C2+C6), 132.0 (br, CHarom/C3+C5), 155.6
(N-Cq/C1), 164.0 (ON-Cq/C4). – 13C NMR (100.63 MHz,
CD2Cl2, −60 ◦C): δ = 9.6 (Cp-CH3), 41.1 (N-CH3), 89.2
(Cp-Cq), 108.1 (CHarom/C2), 112.2 (CHarom/C6), 122.6
(br, CHarom/C3), 140.9 (CHarom/C5), 155.7 (N-Cq/C1),
164.0 (ON-Cq/C4). – MS ((+)-FAB): m/z (%) = 732.8 (2)
[M]+, 605.0 (79) [M-I]+, 477.1 (12) [M-2I]+, 455.0 (100)
[M-I-3]+. – C18H25I2IrN2O (731.43): calcd. C 29.56, H
3.45, N 3.83; found C 29.74, H 3.47, N 3.79.
CDCl3): δ = 1.25 (t, 6 H, 3J = 7.13 Hz, Et-CH3), 1.51
(s, 15 H, Cp-CH3), 3.47 (q, 4 H, 3J = 7.13 Hz, N-CH2),
6.52 (d, 2 H, 3J = 9.78 Hz, CHarom/H2+H6), 8.27 (br, 2
H, CHarom/H3+H5). – 13C NMR (100.53 MHz, CDCl3):
δ = 8.9 (Cp-CH3), 12.8 (Et-CH3), 46.1 (N-CH2), 88.2 (Cp-
Cq), 110.8 (CHarom/C2+C6), 132.6 (br, CHarom/C3+C5),
155.0 (N-Cq/C1), 163.7 (ON-Cq/C4). – MS ((+)-FAB):
m/z (%) = 576.0 (2) [M]+, 541.1 (89) [M-Cl]+, 505.2
(27) [M-2Cl]+, 363.2 (100) [M-Cl-4]+. – C20H29Cl2IrN2O
(576.58): calcd. C 41.66, H 5.07, N 4.86; found C 41.48, H
5.03, N 4.58.
(4-Nitroso-N,N-diethylaniline-N)dibromido(pentamethyl-
η5-cyclopentadienyl)iridium(III) (6b)
Reagents:
149 mg
(0.153 mmol)
1b,
164 mg
(0.918 mmol) 4. Reaction time: 4 h. Yield: 180 mg
(0.270 mmol, 88%) dark-green microcrystalline solid.
Black crystals (blocks) were obtained by slow isothermic
diffusion of n-pentane into a solution of 6b in CHCl3. M. p.
decomp. > 188 ◦C. – IR (CH2Cl2): ν = 3049 (w), 2981
(w), 2919 (w), 2879 (w), 1600 (vs), 1540 (w), 1532 (m),
1488 (w), 1455 (w), 1418 (w), 1383 (w), 1369 ν( N = O)
(w), 1346 (m), 1333 (m), 1308 (m), 1246 (m), 1191 (w),
1167 (w), 1135 (vs), 1075 (m), 1029 (w), 1010 (w), 878
(w), 827 (m), 630 (w), 609 (w), 594 (w) cm−1. – IR (ATR,
solid): ν = 2976 (w), 2962 (w), 2918 (w), 2868 (w), 1598
(s), 1535 (m), 1487 (w), 1466 (w), 1449 (w), 1417 (m),
1375 (w), 1366 ν( N = O) (w), 1356 (w), 1338 (w), 1323
(s), 1300 (s), 1249 (s), 1190 (w), 1168 (w), 1131 (vs),
1073 (s), 1027 (m), 1004 (m), 980 (w), 965 (w), 932
(w), 876 (m), 840 (m), 833 (m), 799 (w), 736 (w), 717
(s), 627 (w), 606 (m) cm−1. – 1H NMR (399.78 MHz,
CDCl3): δ = 1.26 (t, 6 H, 3J = 7.16 Hz, Et-CH3), 1.58
(s, 15 H, Cp-CH3), 3.47 (q, 4 H, 3J = 7.12 Hz, N-CH2),
6.52 (d, 2 H, 3J = 9.19 Hz, CHarom/H2+H6), 8.26 (br, 2
H, CHarom/H3+H5). – 13C NMR (100.53 MHz, CDCl3):
δ = 9.4 (Cp-CH3), 12.8 (Et-CH3), 46.0 (N-CH2), 89.0 (Cp-
Cq), 110.5 (CHarom/C2+C6), 132.5 (br, CHarom/C3+C5),
154.9 (N-Cq/C1), 164.2 (ON-Cq/C4). – MS ((+)-FAB):
m/z (%) = 664.9 (6) [M]+, 585.0 (95) [M-Br]+, 505.2 (38)
[M-2Br]+, 407.1 (100) [M-Br-4]+. – C20H29Br2IrN2O
(665.48): calcd. C 36.10, H 4.39, N 4.21; found C 36.47, H
4.35, N 4.24.
(4-Nitroso-N,N-diethylaniline-N)dichlorido(pentamethyl-
η5-cyclopentadienyl)iridium(III) (6a)
Reagents:
165 mg
(0.207 mmol)
1a,
221 mg
(1.242 mmol) 4. Reaction time: 2 h. Yield: 234 mg
(0.406 mmol, 98%) dark-red microcrystalline solid. Brown
crystals (blocks) were obtained by slow isothermic diffusion
of n-pentane into a solution of 6a in CHCl3. M. p. decomp.
> 186 ◦C. – UV/Vis (CH2Cl2): λmax (ε) = 269 (6500), 426
(15 400), 512 nm (21 400 L mol−1 cm−1). – IR (CH2Cl2):
ν = 3050 (w), 2981 (m), 2923 (m), 2874 (w), 1600 (vs),
1543 (w), 1531 (m), 1481 (w), 1453 (w), 1418 (w), 1383
(m), 1370 ν( N = O) (m), 1346 (m), 1334 (m), 1309 (m),
1248 (m), 1190 (w), 1167 (w), 1137 (vs), 1075 (m), 1029
(w), 1010 (w), 878 (w), 827 (m), 629 (w), 608 (w), 592
(w) cm−1. – IR (ATR, solid): ν = 2965 (w), 2914 (w),
(4-Nitroso-N,N-diethylaniline-N)diiodido(pentamethyl-η5-
cyclopentadienyl)iridium(III) (6c)
Reagents:
245 mg
(0.211 mmol)
1 c,
226 mg
2870 (w), 1597 (s), 1532 (m), 1482 (w), 1448 (w), 1416 (1.266 mmol) 4. Reaction time: 7 h. Yield: 281 mg
Unauthenticated
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540
S. Wirth – I.-P. Lorenz · Reactivity of 4-Nitrosoanilines Towards Dimeric Halogenido-bridged Complexes
(0.370 mmol, 88%) dark-green microcrystalline solid. Black (ATR, solid): ν = 3040 (w), 2988 (w), 2968 (w), 2911 (w),
crystals (blocks) were obtained by slow isothermic diffusion 2856 (w), 1599 (s), 1551 (w), 1533 (w), 1480 (w), 1440 (w),
of n-pentane into a solution of 6c in CH2Cl2. M. p. decomp. 1398 (w), 1382 (w), 1364 ν( N = O) (m), 1336 (vs), 1314
> 179 ◦C. – IR (CH2Cl2): ν = 3044 (w), 2980 (w), 2916 (vs), 1290 (w), 1253 (s), 1225 (w), 1146 (vs), 1082 (w), 1062
(w), 2876 (w), 1600 (vs), 1544 (w), 1525 (m), 1478 (w), (w), 1017 (m), 989 (w), 935 (w), 867 (w), 834 (s), 795 (w),
1
1452 (w), 1416 (w), 1380 ν( N = O) (m), 1347 (m), 1334 736 (s), 628 (m), 608 (m) cm−1. – H NMR (270.17 MHz,
(m), 1307 (m), 1242 (m), 1191 (w), 1166 (w), 1127 (vs), CDCl3): δ = 1.59 (s, 15 H, Cp-CH3), 3.16 (s, 6 H, N-CH3),
1076 (m), 1027 (w), 1010 (w), 877 (w), 826 (m), 630 (w), 6.63 (d, 2 H, 3J = 8.89 Hz, CHarom/H2+H6), 7.91 (br, 2
608 (w), 596 (w) cm−1. – IR (ATR, solid): ν = 2974 (w), H, CHarom/H3+H5). – 13C NMR (67.93 MHz, CDCl3):
2964 (w), 2927 (w), 2910 (w), 2868 (w), 1592 (s), 1540 (m), δ = 9.5 (Cp-CH3), 40.7 (N-CH3), 94.2 (d, 1JRh-C = 8.3 Hz,
1531 (m), 1484 (w), 1464 (w), 1450 (w), 1416 (m), 1356 Cp-Cq), 110.4 (CHarom/C2+C6), 155.7 (N-Cq/C1), 163.0
ν( N = O) (w), 1342 (w), 1321 (s), 1297 (s), 1243 (s), 1188 (ON-Cq/C4)1. – MS ((+)-FAB): m/z (%) = 423.1 (73)
(w), 1167 (w), 1121 (vs), 1069 (s), 1024 (m), 1004 (m), [M-Cl]+, 273.1 (100) [M-Cl-3]+, 237.2 (61) [M-2Cl-3]+. –
973 (w), 961 (w), 929 (w), 868 (m), 836 (m), 826 (m), 790 C18H25Cl2N2ORh (459.21): calcd. C 47.08, H 5.49, N 6.10;
(w), 732 (w), 716 (s), 628 (m), 604 (m) cm−1. – 1H NMR found C 46.49, H 5.39, N 5.78.
3
(399.78 MHz, CDCl3): δ = 1.26 (t, 6 H, J = 7.16 Hz, Et-
(4-Nitroso-N,N-diethylaniline-N)dichlorido(pentamethyl-
CH3), 1.73 (s, 6 H, Cp-CH3), 1.81 (s, 9 H, Cp-CH3), 3.48 (q,
4 H, 3J = 7.24 Hz, N-CH2), 6.58 (br, 2 H, CHarom/H2+H6),
8.28 (br, 2 H, CHarom/H3+H5). – 13C NMR (100.53 MHz,
CDCl3): δ = 10.5 (Cp-CH3), 10.9 (Cp-CH3), 12.7 (Et-
CH3), 45.6 (N-CH2), 89.0 (Cp-Cq), 90.2 (Cq, arom), 110.1
(CHarom/C2+C6), 132.9 (br, CHarom/C3+C5), 154.0
(N-Cq/C1), 164.3 (ON-Cq/C4). – MS ((+)-FAB): m/z (%)
= 760.9 (4) [M]+, 633.0 (100) [M-I]+, 505.2 (19) [M-2I]+,
455.0 (98) [M-I-4]+. – C20H29I2IrN2O (759.48): calcd. C
31.63, H 3.85, N 3.69; found C 32.05, H 3.87, N 3.74.
η5-cyclopentadienyl)rhodium(III) (8a)
Reagents:
138 mg
(0.223 mmol)
2a,
238 mg
(1.338 mmol) 4. Reaction time: 4 h. Yield: 136 mg
(0.279 mmol, 63%) dark-red microcrystalline solid. Green
crystals (blocks) were obtained by slow isothermic diffusion
of n-pentane into a solution of 8a in CHCl3. M. p. decomp.
> 137 ◦C. – IR (CH2Cl2): ν = 3046 (w), 2980 (m), 2917
(w), 2876 (w), 1602 (vs), 1541 (w), 1524 (m), 1478 (w),
1452 (w), 1422 (w), 1377 ν( N = O) (s), 1348 (s), 1335 (s),
1309 (m), 1240 (m), 1192 (w), 1169 (w), 1143 (s), 1123 (vs),
1076 (m), 1022 (w), 1010 (w), 826 (m), 630 (w), 606 (w)
cm−1. – IR (ATR, solid): ν = 3072 (w), 2975 (w), 2966 (w),
2909 (w), 2868 (w), 1598 (s), 1537 (m), 1486 (w), 1468 (w),
1444 (w), 1420 (w), 1366 ν( N = O) (w), 1341 (m), 1330
(s), 1309 (s), 1252 (s), 1189 (w), 1168 (m), 1136 (vs), 1073
(s), 1021 (m), 1007 (m), 931 (w), 870 (m), 846 (m), 800 (w),
Synthesis of the rhodium(III) complexes 7a and 8a
The dimer [(η5-C5Me5)RhCl2]2 (2a) and six equiva-
lents of ligand 3 or 4 were dissolved in 20 mL of dry
dichloromethane and stirred at room temperature. The sol-
vent showed a dark-red color instantly. After the reaction
was completed (see time below) the dichloromethane was
removed in vacuo. For purification 20 mL of dry Et2O was
added, and the mixture was stirred for 30 min at room tem-
perature. Then, the precipitate was separated by centrifuga-
tion and Et2O was removed with a cannula. This procedure
was repeated 3 times to remove excess ligand, and the result-
ing product was dried in vacuo for 12 h at 50 ◦C.
1
715 (s), 628 (w), 605 (m) cm−1. – H NMR (399.78 MHz,
CDCl3): δ = 1.26 (t, 6 H, 3J = 7.16 Hz, Et-CH3), 1.60 (s,
15 H, Cp-CH3), 3.50 (q, 4 H, 3J = 7.12 Hz, N-CH2), 6.61
(br, 2 H, CHarom/H2+H6), 9.02 (br, 2 H, CHarom/H3+H5).
–
13C NMR (100.53 MHz, CDCl3): δ = 9.5 (Cp-CH3),
1
12.8 (Et-CH3), 45.6 (N-CH2), 94.2 (d, JRh-C = 8.6 Hz,
Cp-Cq), 110.1 (CHarom/C2+C6), 154.0 (N-Cq/C1), 162.7
(ON-Cq/C4)2. – MS ((+)-FAB): m/z (%) = 451.1 (87)
[M-Cl]+, 273.1 (100) [M-Cl-4]+, 237.2 (58) [M-2Cl-4]+. –
C20H29Cl2N2ORh (487.27): calcd. C 49.30, H 6.00, N 5.75;
found C 48.83, H 5.86, N 4.65.
(4-Nitroso-N,N-dimethylaniline-N)dichlorido(pentamethyl-
η5-cyclopentadienyl)rhodium(III) (7a)
Reagents:
142 mg
(0.230 mmol)
2a,
207 mg
(1.380 mmol) 3. Reaction time: 2 h. Yield: 164 mg
(0.357 mmol, 78%) red microcrystalline solid. Red crystals
(platelets) were obtained by slow isothermic diffusion of
n-pentane into a solution of 7a in CHCl3. M. p. decomp.
> 177 ◦C. – IR (CH2Cl2): ν = 3049 (w), 2978 (w), 2919 (w),
2864 (w), 1604 (vs), 1556 (w), 1530 (m), 1477 (w), 1444
(w), 1418 (w), 1402 (w), 1365 ν( N = O) (s), 1339 (s), 1310
(m), 1229 (m), 1143 (s), 1123 (vs), 1022 (w), 991 (w), 940
(w), 871(w), 825 (m), 632 (w), 606 (w), 585 (w) cm−1. – IR
Single-crystal structure determinations
Single-crystal X-ray data were collected using a Nonius
Kappa CCD diffractometer equipped with a rotating anode
1Signal for C3+C5 (too broad) not detected.
2Signal for C3+C5 (too broad) not detected.
Unauthenticated
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S. Wirth – I.-P. Lorenz · Reactivity of 4-Nitrosoanilines Towards Dimeric Halogenido-bridged Complexes
541
generator using graphite-monochromatized MoKα radiation added as proof of the coordination but should not be used for
˚
(λ = 0.71073 A). All structures were solved by Direct Meth- a detailed discussion because the final refinement R values
ods with the SHELXS [61] software and refined by full-matrix were relatively poor.
least-squares on F2 with SHELXL-97 [61] using anisotropic
CCDC 881822–881828 (see Table 3) contain the supple-
displacement parameters for all non-hydrogen atoms. All hy- mentary crystallographic data for this paper. These data can
drogen atoms were calculated in ideal positions as riding be obtained free of charge from The Cambridge Crystallo-
atoms (except hydrogen bonds in 6a) by using isotropic dis- graphic Data Centre via www.ccdc.cam.ac.uk/data request/
placement parameters. The structure determination of 8a was cif.
[1] A. Baeyer, H. Caro, Ber. Dtsch. Chem. Ges. 1874, 7, [24] C. J. Popp, R. O. Ragsdale, Inorg. Chem. 1968, 7,
809 – 811.
1845 – 1848.
[2] A. Baeyer, H. Caro, Ber. Dtsch. Chem. Ges. 1874, 7, [25] R. Wilberger, C. Krinninger, H. Piotrowski, P. Mayer,
963 – 968.
I.-P. Lorenz, Eur. J. Inorg. Chem. 2004, 2488 – 2492.
[26] C. Krinninger, C. Ho¨gg, H. No¨th, J. C. G. Ruiz,
P. Mayer, O. Burkacky, A. Zumbusch, I.-P. Lorenz,
Chem. Eur. J. 2005, 11, 7228 – 7236.
[3] A. Baeyer, Ber. Dtsch. Chem. Ges. 1874, 7, 1638 –
1640.
[4] R. H. Pickard, J. Kenyon, J. Chem. Soc., Trans. 1907,
91, 896 – 905.
[27] H. L. M. van Gaal, J. P. J. Verlaan, J. Organomet.
[5] B. G. Gowenlock, G. B. Richter-Addo, Chem. Rev.
2004, 104, 3315 – 3340.
[6] B. G. Gowenlock, G. B. Richter-Addo, Chem. Soc. Rev.
2005, 34, 797 – 809.
[7] B. G. Gowenlock, G. B. Richter-Addo, J. Chem. Educ.
2008, 85, 1243 – 1245.
Chem. 1977, 133, 93 – 105.
[28] G. Vasapollo, P. Giannoccaro, C. F. Nobile, F. Alle-
gretta, J. Organomet. Chem. 1984, 270, 109 – 114.
[29] G. Vasapollo, C. F. Nobile, P. Giannoccaro, F. Alle-
gretta, J. Organomet. Chem. 1984, 277, 417 – 422.
[30] G. Vasapollo, A. Sacco, C. F. Nobile, M. A. Pellin-
ghelli, M. Lanfranchi, J. Organomet. Chem. 1988, 353,
119 – 123.
[8] M. Cameron, B. G. Gowenlock, G. Vasapollo, Chem.
Soc. Rev. 1990, 19, 355 – 379.
[9] J. Lee, L. Chen, A. H. West, G. B. Richter-Addo, Chem. [31] G. Vasapollo, C. F. Nobile, A. Sacco, B. G. Gowen-
Rev. 2002, 102, 1019 – 1066.
[10] H. Yamamoto, N. Momiyama, Chem. Commun. 2005,
3514 – 3525.
[11] W. Adam, O. Krebs, Chem. Rev. 2003, 103, 4131 –
4146.
lock, L. Sabbatini, C. Malitesta, P. G. Zambonin, J.
Organomet. Chem. 1989, 378, 239 – 244.
[32] G.-e. Matsubayashi, T. Tanaka, J. Chem. Soc., Dalton
Trans. 1990, 437 – 441.
[33] M. Cameron, B. G. Gowenlock, G. Vasapollo, Polyhe-
[12] H. Waldmann, Synthesis 1994, 1994, 535 – 551.
[13] J. Streith, A. Defoin, Synthesis 1994, 1994, 1107 –
1117.
[14] P. F. Vogt, M. J. Miller, Tetrahedron 1998, 54, 1317 –
1348.
dron 1994, 13, 1371 – 1377.
[34] R. Rella, P. Siciliano, A. Tepore, L. Valli, G. Vasapollo,
Mater. Sci. Forum 1996, 203, 155 – 160.
[35] R. Rella, A. Serra, G. Vasapollo, L. Valli, Thin Solid
Films 1996, 284 – 285, 69 – 72.
[15] D. Keilin, E. F. Hartree, Nature 1940, 151, 390 – 391.
[16] Q. H. Gibson, Biochem. J. 1960, 77, 519 – 526.
[17] M. Murayama, J. Biol. Chem. 1960, 235, 1024 – 1028.
[18] J. B. Schenkman, B. J. Wilson, D. L. Cinti, Biochem.
Pharmacol. 1972, 21, 2373 – 2383.
[36] S. Wirth, F. Barth, I.-P. Lorenz, Dalton Trans. 2012, 41,
2176 – 2186.
[37] P. R. Sharp, D. W. Hoard, C. L. Barnes, J. Am. Chem.
Soc. 1990, 112, 2024 – 2026.
[38] D. W. Hoard, P. R. Sharp, Inorg. Chem. 1993, 32,
612 – 620.
[19] M. R. Franklin, Mol. Pharmacol. 1974, 10, 975 – 985.
[20] D. Mansuy, P. Beaune, J. C. Chottard, J. F. Bartoli, [39] T. Iwasa, H. Shimada, A. Takami, H. Matsuzaka, Y.
P. Gans, Biochem. Pharmacol. 1976, 25, 609 – 612.
[21] D. Mansuy, P. Battioni, J. C. Chottard, M. Lange, J. Am.
Chem. Soc. 1977, 99, 6441 – 6443.
[22] D. Mansuy, P. Beaune, T. Cresteil, C. Bacot, J.-C. Chot-
tard, P. Gans, Eur. J. Biochem. 1978, 86, 573 – 579.
[23] D. M. Gooden, H. Chakrapani, E. J. Toone, Curr. Top.
Med. Chem. 2005, 5, 687 – 705.
Ishii, M. Hidai, Inorg. Chem. 1999, 38, 2851 –
2859.
[40] M. Cameron, B. G. Gowenlock, R. V. Parish, G. Vasa-
pollo, J. Organomet. Chem. 1994, 465, 161 – 166.
[41] B. G. Gowenlock, M. J. Maidment, K. G. Orrell, I.
Prokes, J. R. Roberts, J. Chem. Soc., Perkin Trans. 2
2001, 1904 – 1911.
Unauthenticated
Download Date | 6/9/17 11:35 AM

542
S. Wirth – I.-P. Lorenz · Reactivity of 4-Nitrosoanilines Towards Dimeric Halogenido-bridged Complexes
[42] B. M. Al-Tahou, B. G. Gowenlock, Recl. Trav. Chim. [53] M.-T. Youinou, R. Ziessel, J. Organomet. Chem. 1989,
Pays-Bas 1986, 105, 353 – 355. 363, 197 – 208.
[43] B. G. Gowenlock, M. Cameron, A. S. F. Boyd, B. M. [54] D. M. Tellers, R. G. Bergman, Organometallics 2001,
Al-Tahou, P. McKenna, Can. J. Chem. 1994, 72,
20, 4819 – 4832.
514 – 518.
[55] S. Greulich, A. Klein, A. Knodler, W. Kaim, Organo-
ˇ
[44] D. A. Fletcher, B. G. Gowenlock, K. G. Orrell, V. Sik,
metallics 2002, 21, 765 – 769.
Magn. Reson. Chem. 1995, 33, 561 – 569.
[45] M. Cameron, B. G. Gowenlock, G. Vasapollo, J.
Organomet. Chem. 1989, 378, 493 – 496.
[46] H. J. Talberg, Acta Chem. Scand. 1977, 31a, 743 – 751.
[56] P. Govindaswamy, Y. A. Mozharivskyj, M. R. Kolli-
para, Polyhedron 2005, 24, 1710 – 1716.
[57] D. F. Kennedy, B. A. Messerle, M. K. Smith, Eur. J. In-
org. Chem. 2007, 2007, 80 – 89.
[47] B. G. Gowenlock, K. G. Orrell, V. Sik, G. Vasapollo, [58] R. G. Ball, W. A. G. Graham, D. M. Heinekey, J. K.
Polyhedron 1998, 17, 3495 – 3500.
[48] C. Rømming, H. J. Talberg, Acta. Chem. Scand. 1973,
27, 2246 – 2248.
[49] M. R. Churchill, S. A. Julis, Inorg. Chem. 1977, 16,
1488 – 1494.
Hoyano, A. D. McMaster, B. M. Mattson, S. T. Michel,
Inorg. Chem. 1990, 29, 2023 – 2025.
[59] D. S. Gill, P. M. Maitlis, J. Organomet. Chem. 1975, 87,
359 – 364.
[60] J. W. Kang, K. Moseley, P. M. Maitlis, J. Am. Chem.
[50] M. R. Churchill, S. A. Julis, Inorg. Chem. 1979, 18,
1215 – 1221.
[51] M. R. Churchill, S. A. Julis, F. J. Rotella, Inorg. Chem.
1977, 16, 1137 – 1141.
[52] N. Escola, A. Llebar´ıa, G. Leitus, F. Doctorovich,
Organometallics 2006, 25, 3799 – 3801.
Soc. 1969, 91, 5970 – 5977.
[61] G. M. Sheldrick, SHELXS/L-97, Programs for Crys-
tal Structure Determination, University of Go¨ttingen,
Go¨ttingen (Germany) 1997. See also: G. M. Sheldrick,
Acta Crystallogr. 1990, A46, 467 – 473; ibid. 2008,
A64, 112 – 122.
Unauthenticated
Download Date | 6/9/17 11:35 AM