Opening of the azastibol heterocycle with various acids: Isolation of novel N, C-chelated organoantimony(III) compounds

Article abstract of DOI:10.1016/j.jorganchem.2013.06.023

The reaction of N,C-intramolecularly coordinated organoantimony(III) compound L₂SbCl (1) (where L is [2-(2′,6′-i-Pr ₂C₆H₃)N]CHC₆H₄]) with one molar equivalent of the K-selectride (K[B(

Full text of DOI:10.1016/j.jorganchem.2013.06.023

Journal of Organometallic Chemistry 743 (2013) 156e162
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Opening of the azastibol heterocycle with various acids: Isolation of
novel N,C-chelated organoantimony(III) compounds
a
a
a
a
b
ꢀ ꢁꢀ ꢀ
Iva Urbanová , Milan Erben , Roman Jambor , Ales Ruzicka , Robert Jirásko ,
,
Libor Dostál a
*
a Department of General and Inorganic Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentská 573, CZ-532 10 Pardubice, Czech
Republic
b Department of Analytical Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentská 573, CZ-532 10 Pardubice, Czech Republic
a r t i c l e i n f o
a b s t r a c t
Article history:
The reaction of N,C-intramolecularly coordinated organoantimony(III) compound L2SbCl (1) (where L is
[2-(20,60-i-Pr2C6H3)N]CHC6H4]) with one molar equivalent of the K-selectride (K[B(s-Bu)3H]) gave
compound LSb{2-[CH2N(20,60-i-Pr2C6H3)]C6H4} (2) containing five membered aza-stiba heterocycle. On
the contrary, analogical reaction between the organobismuth(III) compound L2BiCl (3) and K-selectride
gave only inseparable mixture of products. Reactions of 2 with selected acids HX resulted in the cleavage
of the present SbeN bond and formation of novel N,C-chelated compounds LSb(X){2-[CH2NH(20,60-i-
Pr2C6H3)]C6H4} (where X ¼ Cl (4), CH3COO (5), CF3COO (6), CF3SO3 (7) or FcCOO (8); Fc ¼ ferrocenyl).
Compounds 4e8 were characterized by the help of elemental analysis, electrospray ionization (ESI) mass
spectrometry, multinuclear NMR spectroscopy, IR spectroscopy and in the case of 5 by the single-crystal
X-ray diffraction analysis. The molecular structures of compounds LSb(X){2-[CH2NH(20,60-i-Pr2C6H3)]
C6H4}$HX (where X ¼ CF3COO (6a), CF3SO3 (7a)) were determined by the single-crystal X-ray diffraction
analysis as well. Compounds 6a and 7a are most probably products of partial hydrolysis of compounds 6
and 7.
Received 24 April 2013
Received in revised form
17 June 2013
Accepted 20 June 2013
Keywords:
Antimony
Azastiboles
Chelating ligands
X-ray structures
NMR
Ó 2013 Elsevier B.V. All rights reserved.
1. Introduction
bonds [6], highly Lewis acidic antimony and bismuth cations [7],
and many mixed oxido-compounds [8] may serve as representative
The utilization of various types of Y,C- or Y,C,Y-chelating ligands
(Y designates a donor atom such as N or O) for stabilization of
organoantimony(III) and organobismuth(III) compounds is well
known phenomenon in the chemistry of heavier group 15 elements
[1]. In this regard, the pioneer works of Cowley [2], Silvestru and
Breunig [3], and later on by our group and others [4] are note-
worthy. The majority of compounds contain chelating ligands with
nitrogen atom as in-built donor functionality. The initial efforts in
the field were mainly focused on the description of strength of
N / Sb(Bi) interactions and their influence on the coordination
numbers of the central atom and(or) structures of studied com-
pounds. Later on, it turned out that the stabilization of the central
antimony or bismuth atoms by N,C,N-chelating ligands is not
pointless, but allowed isolation of many, before elusive, antimony
and bismuth compounds. The monomeric stibinidine and bismu-
thinide [5], compounds containing terminal M]E (E ¼ S, Se, Te)
examples of this research. Reports describing compounds con-
taining related O,C,O-chelating ligands were published by Jurkschat
et al. and our group [9]. The common feature of these O,C,O-
chelated antimony and bismuth compounds is their tendency to
form oxa-stiba heterocycles (Scheme 1), thus, changing the former
O / Sb donoreacceptor interaction into a SbeO bond [9,10]. On the
contrary, such cyclization procedure was, to the best of our
knowledge, unknown for related N,C-chelated compounds.
New type of N,C-chelating ligand [2-(20,60-i-Pr2C6H3)N]
CHC6H4], designated as L hereafter, has been recently introduced by
Mehring and us to the field of antimony and bismuth chemistry
[11,12]. Besides the excellent donor ability of the imino-nitrogen
donor centre and significant sterical shielding of the metal atom by
bulky aromatic group attached to the imino-nitrogen atom, this
ligand carries a C]N functionality. The presence of this functional
group is not of marginal importance for main group element
compounds as demonstrated in the field of boron chemistry, where
the benzazaboroles were obtained by the reaction of the N,C-
chelated chloroboranes by ligand L with lithium anilides. This
procedure involves a nucleophilic addition across the C]N double
* Corresponding author.
E-mail address: libor.dostal@upce.cz (L. Dostál).
0022-328X/$ e see front matter Ó 2013 Elsevier B.V. All rights reserved.
http://dx.doi.org/10.1016/j.jorganchem.2013.06.023

I. Urbanová et al. / Journal of Organometallic Chemistry 743 (2013) 156e162
157
observed most probably indicating that N / Bi interaction is rigid
on the 1H NMR time scale and the two ligands are non-equivalent at
this temperature. The molecular structure of 3 was unambiguously
established by the help of single-crystal X-ray diffraction analysis
(Fig. 1). Both nitrogen atoms N(1) and N(2) are coordinated to the
central atom Bi(1), but the bond distances point to a different
strength of these contacts Bi(1)eN(1) 2.614(3) vs. Bi(1)eN(2)
O
OEt
EtO
EtO
EtO
P
O
P
O
t-Bu
BiCl
O
t-Bu
BiCl2
O
-EtCl
P
P
EtO
EtO
ꢁ
2.916(3) A, as suggested already in solution vide supra. Neverthe-
ref. [10]
EtO
less, if weaker interaction with the N(2) atom and the lone pair of
the central atom are taken into account, the resulting coordination
polyhedron of the central atom may be described as strongly dis-
torted octahedron, where the central bismuth atom is [4 þ 1] co-
ordinated. Unfortunately, all reactions of 3 with K-selectride
produced only mixtures of products and, thus, formation of bis-
muth analogue of 2 failed.
O
O
Cl
SbCl2
O
Sb
O
-t-BuCl
2.1. Reactions of HX with 2
ref. [11]
The treatment of 2 with selected acids HX resulted in the
cleavage of the SbeN bond and formation of novel N,C-chelated
compounds LSb(X){2-[CH2NH(20,60-i-Pr2C6H3)]C6H4} (where X ¼ Cl
(4), CH3COO (5), CF3COO (6), CF3SO3 (7) or FcCOO (8);
Fc ¼ ferrocenyl, Scheme 3).
Scheme 1. Syntheses of known oxastiboles based on O,C,O-chelating ligands.
bond of the ligand L and closure of benzazaborole rings [13]. By an
analogy, we have recently discovered that the reaction between
compound L2SbCl (1) and one molar equivalent of the K-selectride
(K[B(s-Bu)3H]) gave compound LSb{2-[CH2N(20,60-i-Pr2C6H3)]C6H4}
(2) as a result of hydrogen atom migration and formation of the Sbe
N bond (Scheme 2). This procedure also led to the saturation of the
C]N double bond of the ligand L [11a].
Herein, we report on the reaction of compound 2 with various
HX acids with the aim to open the azastibol heterocycle via cleav-
age of the present SbeN bond. The synthesis and characterization
of compound L2BiCl (3) as a possible precursor for formation bis-
muth analogue of compound 2 are also included.
Compounds 4e8 were characterized by the help of elemental
analysis and ESI mass spectroscopy. In the mass spectra, the
observation of ions [M ꢀ X]þ (X ¼ Cl for 4, CH3COO for 5, CF3COO for
6, CF3SO3 for 7 and FcCOO for 8) as well as of other ions (see
Experimental) proved the identity of studied compounds [14].
Infrared spectroscopy unambiguously proved the presence of the
NH group by the observation of the characteristic weak-to-medium
bands in the range of 3344e3357 cmꢀ1 for 4e8. Furthermore, the
presence of carbonyl functionalities in 5, 6 and 8 was evidenced by
the detection of bands corresponding to the na(CO2) vibration at
1636, 1702 and 1628 cmꢀ1 for 5, 6 and 8, respectively. Triflate anion
in 7 gives characteristic strong bands of SeO and CeF stretch at
1306, 1023, 1231 and 1213 cmꢀ1 [15].
2. Results and discussion
The 1H NMR spectra of 4e8 clearly established the proposed
structure in solution (Fig. 2).
The reaction of 1 with one molar equivalent of the K-selectride
gave 2 according to Scheme 2 [11].
The 1H NMR spectra of 4e8 revealed typical AX pattern for the
CH2NH group, one broad signal for NH proton and the signal for
In order to test similar reaction with the bismuth analogue,
compound L2BiCl (3) was prepared by the reaction of LLi with BiCl3
in molar ratio of 2:1. Compound 3 could be isolated in rather low
yield of 11% in the form of bright yellow air-stable crystals. Com-
pound 3 was characterized by the help of elemental analysis, ESI
mass spectrometry. The 1H NMR spectrum of 3 revealed one set of
broaden signals for both ligands L at 294 K and upon cooling of the
sample in CDCl3 to 220 K the splitting of these resonances into two
set of independent signals for two non-equivalent ligands L was
N
N
Sb
+K[B(s-Bu)3H]
SbCl
THF/ -KCl, - B(sBu)3
2
N
(1)
Fig. 1. ORTEP view of 3. The thermal ellipsoids are drawn with 40% probability.
Hydrogen atoms are omitted for clarity. Only one position of one of the disordered i-Pr
groups is shown. Selected bond distances (A) and angles ( ): Bi(1)eC(1) 2.275(4),
Bi(1)eC(20) 2.268(4), Bi(1)eN(1) 2.614(3), Bi(1)eN(2) 2.916(3), Bi(1)eCl(1) 2.6086(9),
N(1)eBi(1)eCl(1) 160.52(8), C(1)eBi(1)eN(2) 159.71(11).
(2)
ꢁ
ꢁ
Scheme 2. Synthesis of compound 2.

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I. Urbanová et al. / Journal of Organometallic Chemistry 743 (2013) 156e162
N
H
N
X
Sb
Sb
+ HX
N
N
X = Cl (4), CH3COO (5), CF3COO (6),
CF3SO3 (7), FcCOO (8)
(2)
Scheme 3. Syntheses of compound 4e8.
Fig. 3. ORTEP view of 5. The thermal ellipsoids are drawn with 40% probability.
CH]N group in mutual integral ration of 2:1:1. One set of sharp
signals was observed for the i-Pr groups of the coordinated CH]
N(Dipp) (Dipp ¼ diisopropylphenyl) group. On the contrary, signals
of the i-Pr groups belonging to the non-coordinated CH2NH(Dipp)
were obtained as broaden set of signals most probably reflecting
hindered rotation of this group. This may be caused either by a
steric hindrance or by the presence of hydrogen bond between the
NH group and polar atoms of the group X as observed in the solid
state (vide infra). The 13C NMR spectra revealed the presence of one
CH]N group (signals in the range of 168.4 and 170.5 ppm in 4e8)
and one CH2NH group (signals between 58.7 and 59.1 ppm in 4e8),
thus, proving the proposed structure of 4e8.
Hydrogen atoms ꢁexcept the NH group are omitted for clarity. Selected bond distances
ꢁ
(A) and angles ( ): Sb(1)eC(1) 2.145(4), Sb(1)eC(20) 2.149(3), Bi(1)eN(1) 2.614(3),
Bi(1)eO(1) 2.484(3), Bi(1)eO(2) 2.944(3), C(7)eN(1) 1.290(5), C(26)eN(2) 1.480(5),
N(2)eO(2) 3.596(4), N(1)eSb(1)eO(1) 154.89(9), C(1)eSb(1)eC(20) 100.88(12), N(2)e
HeO(2) 147.
The acetate group is bonded to the central atom in a monodentate
fashion as demonstrated by the fairly different bond distances
ꢁ
Sb(1)eO(1) and Sb(1)eO(2) being 2.484(3) and 2.944(3) A,
respectively. The coordination polyhedron of the central atom in 5
may be described as pseudo-trigonal bipyramid with the lone pair,
C(1) and C(20) located in equatorial positions, while N(1) and O(1)
atoms occupy the axial positions as demonstrated by the bonding
angle N(1)eSb(1)eO(1) 154.89(9)ꢁ. The oxygen atom O(2) of the
acetate group is involved in a weak hydrogen bond with the
hydrogen atom of the NH group, that is characterized by the bond
The molecular structure of 5 was unambiguously determined by
the help of single-crystal X-ray diffraction analysis (Fig. 3).
The central atom Sb(1) is four coordinated and the bond dis-
ꢁ
tance Sb(1)eN(1) of 2.484(3) A indicates the presence of strong
ꢁ
intramolecular N / Sb interaction. The nitrogen atom N(2) with
distance O(2)eN(1) of 3.596 A and the bonding angle O(2)eHeN(1)
the bond distance Sb(1)eN(2) of 4.322(3) A is out of the coordi-
of 147ꢁ.
ꢁ
nation sphere of the central atom. The difference between the bond
distances C(7)eN(1) 1.290(5) A and C(26)eN(2) 1.480(5) A clearly
proves the presence of CH]N and CH2eNH bonds, respectively.
Unfortunately, all other attempts to grow single-crystals of 4 or
6e8 failed. After slow evaporation of solutions of 6 and 7 a tiny
amount of single-crystals was found in both mixtures and their
ꢁ
ꢁ
Fig. 2. Typical 1H NMR spectrum of compounds 4e8 illustrated on the example of the spectrum of 4.

I. Urbanová et al. / Journal of Organometallic Chemistry 743 (2013) 156e162
159
The molecular structures of 6a and 7a are depicted together
with selected structural parameters in Figs. 4 and 5.
The molecular structure of 6a and 7a is closely related to that
found for 5. The central antimony atom is N,C-chelated by the
ligand L (the bond distances Sb(1)eN(2) 2.346(3) and 2.259(3) for
6a and 7a, respectively), while the second ligand is bonded only
via ipso SbeC bond. The coordination polyhedron of the antimony
atom in 6a and 7a is again a pseudo-trigonal bipyramid with the
O(1) and N(2) placed in axial positions, similarly to 5. The oxygen
atoms O(3) in the case of 6a and O(2) in 7a are involved in a
hydrogen bond with the amino-group as demonstrated by the
bond distances O(3)eN(1) of 2.908(4) for 6a (the bonding angle
O(3)eHeN(1) is 150ꢁ) and O(2)eN(1) of 2.841(3) for 7a (the
bonding angle O(2)eHeN(1) is 155ꢁ). In contrast to 5, there is
another molecule of the acid coordinated to the nitrogen atom
N(1) in 6a and 7a. The bond distances and bonding angles
describing these hydrogen atoms are O(2)eN(1) 2.619(5) for 6a
(O(2)eHeN(1) 153ꢁ) and O(4)eN(1) 2.774(4) for 7a (O(4)eHeN(1)
174ꢁ).
3. Conclusion
Fig. 4. ORTEP view of 6a. The thermal ellipsoids are drawn with 40% probability.
Hydrogen atoms except the NH group are omitted for clarity.
It was demonstrated that compound 2 containing central
azastibole five-membered heterocycle is an excellent precursor for
preparation of a variety of substituted organoantimony(III) com-
pounds using simple and high-yield procedure. These compounds
carry NH functionality in their structures, which may be interesting
for further reactivity studies. Investigation dealing with the prep-
aration of similar azametal heterocycles based on the ligand L is
currently in progress in our labs.
molecular structures were determined by the single-crystal X-ray
diffraction analysis. It turned out that the revealed structures
correspond to the adducts between one molecule of the corre-
sponding acid and expected products 6$(CF3COOH) (6a) and
7$(CF3SO3H) (7a). The attempts to prepare 6a or 7a in high yield via
reaction of 2 with two molar equivalents of corresponding acids
were unsuccessful. The lack of sufficient amount of pure material of
6a and 7a hampered complex analytical studies and only IR spectra
of manually separated single-crystals of 6a and 7a were recorded.
In the IR spectrum of single-crystals of 6a, broad medium absorp-
tion at 3196 cmꢀ1 and twinned band of carbonyl vibration (1705
and 1678 cmꢀ1) were observed. Band at 3196 cmꢀ1 could be
4. Experimental
4.1. General methods
The starting compounds 1 and 2 [11a] and precursor of the
ligand LBr [16] were prepared according to the literature pro-
cedures. All solvents were dried by standard procedures. Starting
acids were obtained from commercial suppliers and used as
delivered. The 1H and 13C NMR spectra were recorded on a
Bruker 400 spectrometer at room temperature in CDCl3 or in the
temperature range 220e294 K in CDCl3 in the case of 3. The 1H,
assigned to
n(OH) of CF3COOH molecule involved in strong
hydrogen bond towards secondary amine function [16]. Infrared
spectrum of 7a also contained band significantly broadened over
the region 3600e3200 cmꢀ1 attributable to the presence of free
triflic acid in the sample. IR bands characteristic for the presence of
triflate anion were also broadened but not twinned.
13C NMR chemical shifts
central peaks of residual signal of the CDCl3
d are given in ppm and referenced to the
(
d
(1H) ¼ 7.27 ppm,
d
(
13C) ¼ 77.23 ppm). Elemental analyses were performed on an
LECO-CHNS-932 analyzer. Positive-ion and negative-ion electro-
spray ionization (ESI) mass spectra were measured on an Esquire
3000 ion trap analyzer (Bruker Daltonics, Bremen, Germany) in
the range m/z 50e1500. Samples were dissolved in acetonitrile
and analyzed by direct infusion at a flow rate of 5 mL/min. The
ion-source temperature was 300 ꢁC, the tuning parameter com-
pound stability was 100%, and the flow rate and the pressure of
nitrogen were 4 L/min and 10 psi, respectively. Infrared spectra
were recorded in 4000e350 cmꢀ1 region on a Nicolet 6700 FTIR
spectrometer using diamond ATR technique.
4.2. Synthesis of compound 3
4.2.1. {2-[CH]N(20,60-i-Pr2C6H3)]C6H4}2BiCl (3)
n-Buli (2.5 mL, 4.03 mmol, 1.6 M solution in hexane) was added
to a solution o-C6H4(CH]NC6H3iPr2-2,6)Br (1.39 g, 4.03 mmol) in
diethyl ether (50 mL) at ꢀ70 ꢁC and stirred for 1 h. The resulting
yellow suspension of lithium compound was added to a solution of
BiCl3 (0.634, 2.01 mmol) in diethyl ether (25 mL) precooled to 0 ꢁC.
The resulting mixture was allowed to reach room temperature and
Fig. 5. ORTEP view of 7a. The thermal ellipsoids are drawn with 40% probability.
Hydrogen atoms except the NH group are omitted for clarity.

160
I. Urbanová et al. / Journal of Organometallic Chemistry 743 (2013) 156e162
stirred for an additional 20 h. The volume of the reaction was
reduced to around 25 mL. The insoluble material was filtered off
and washed with hexane (10 mL). The remaining yellowish solid
was extracted by dichloromethane (30 mL) and 10 mL of hexane
was added to the extract. This solution was slowly evaporated to
obtain single-crystals of 3 suitable for X-ray studies. Yield 0.16 g,
4.3.3. {2-[CH]N(20,60-i-Pr2C6H3)]C6H4}Sb(CF3COO)[{2-
[CH2NH(20,60-i-Pr2C6H3)]C6H4} (6)
Compound
CF3COOH (8
Yield of 6 0.064 g, 80%; m.p. 190 ꢁC. 1H NMR (400 MHz, C6D6, 25 ꢁC):
¼ 0.40 (d (broad), 3H, CH(CH3)2), 0.69 (d (broad), 3H, CH(CH3)2),
6
was prepared analogously to compound 4.
m
L, 0.11 mmol); compound 3 (0.067 g, 0.11 mmol).
d
11%; m.p. 190 ꢁC. 1H NMR (400 MHz, CDCl3, 25 ꢁC):
d
¼ 0.47 (s
0.81 (d (broad), 3H, CH(CH3)2), 0.97 (d (broad), 3H, CH(CH3)2), 1.21
(d, 6H, CH(CH3)2), 1.28 (d, 6H, CH(CH3)2), 1.60 (sept (broad), 1H,
CH(CH3)2eNH(2,6-i-Pr2C6H3)), 2.93 (sept (broad), 1H, CH(CH3)2e
NH(2,6-i-Pr2C6H3)), 3.26 (sept, 2H, CH(CH3)2eCH]N(2,6-i-
Pr2C6H3)), 4.16 (t (broad), 1H, NH(2,6-i-Pr2C6H3)), 3.69 a 4.30 (AX
system, 2H, NCH2), 6.73e7.14 (m, 10H, Ar-H, NH(2,6-i-Pr2C6H3) and
CH]N(2,6-i-Pr2C6H3)) 7.24 (m, 2H, C6H4), 7.36 (d, 1H, C6H4), 7.87 (s,
1H, CH]N(2,6-i-Pr2C6H3)), 8.65 (d, 1H, C6H4). 13C NMR
(broad), 3H, CH(CH3)2), 1.06 (m (broad), 21H, CH(CH3)2), 1.97 (sept
(broad), 1H, CH(CH3)2), 2.82 (m (broad), 3H, CH(CH3)2), 7.13 (m
(broad), 6H, CH]N(2,6-i-Pr2C6H3)), 7.74 (m (broad), 6H, C6H4), 8.37
(m (broad), 2H, C6H4 and CH]N(2,6-i-Pr2C6H3)), 8.98 (m (broad),
1H, CH]N), 9.25 (m (broad), 1H, C6H4). Anal. calcd for C38H44N2BiCl
(773.27 g molꢀ1): C 44.9, H 4.4; Found C 45.2, H 4.7. ESIeMS:
Positive mode e m/z 737 [MeCl]þ (100%). Negative mode e m/z 578
[LBiCl3]ꢀ (100%).
(100.61 MHz, C6D6, 25 ꢁC):
d
¼ 25.0, 25.1 a 28.4 (s, CH(CH3)2 and
CH(CH3)2), 58.9 (s, NCH2), 116.7 (q, CF3C]O, 1J(19F,13C) ¼ 290 Hz),
124.3, 124.4, 124.6, 128.1, 129.1, 129.9, 130.0, 130.5, 133.4, 135.1,
135.5, 137.4, 139.6, 141.0, 142.8, 143.3, 144.2, 145.9, 146.0, 153.1 (s,
C6H4), 161.6 (q, CF3C]O, 2J(19F,13C) ¼ 38 Hz), 170.5 (s, CH]N(2,6-i-
Pr2C6H3)). Anal. calcd for C40H46N2SbO2F3 (765.07 g molꢀ1) C 62.8,
H 6.1; Found C 62.9, H 6.4. ESIeMS: Positive mode e m/z 803
[M þ K]þ (5%); m/z 651 [M-CF3COO]þ (100%); m/z 649 [Me
CF3COOeH2]þ (6%). Negative mode e (clusters of CF3COONa): m/z
1065(CF3COONa)7 þ CF3COO]ꢀ (2%); m/z 929 [(CF3COONa)6 þ CF3
COO]ꢀ (4%); m/z 793 [(CF3COONa)5 þ CF3COO]ꢀ (11%); m/z 657
[(CF3COONa)4 þ CF3COO]ꢀ (29%); m/z 521 [(CF3COONa)3 þ C
F3COO]ꢀ (100%); m/z 385 [(CF3COONa)2 þ CF3COO]ꢀ (29%); m/z 249
[CF3COONa þ CF3COO]ꢀ (89%); m/z 113 [CF3COO]ꢀ (8%); m/z 69
4.3. Synthesis of compounds 4e8
4.3.1. {2-[CH]N(20,60-i-Pr2C6H3)]C6H4}Sb(Cl){2-[CH2NH(20,60-i-
Pr2C6H3)]C6H4} (4)
HCl (20 mL, 0.08 mmol, 4 M solution in dioxane) was added to a
suspension of compound 3 (0.05 g, 0.08 mmol) in hexane (10 mL).
The resulting mixture was stirred for an additional 1 h at room
temperature. Evaporation of the mixture gave yellow powder,
which was washed with hexane (5 mL), dried in vacuo and char-
acterized 4. Yield 0.05 g, 85%; m.p. 123e124 ꢁC. 1H NMR (400 MHz,
C6D6, 25 ꢁC):
d
¼ 0.52 (d (broad), 3H, CH(CH3)2), 0.90 (d (broad), 9H,
CH(CH3)2), 1.18 (d, 6H, CH(CH3)2), 1.24 (d, 6H, CH(CH3)2), 1.88 (sept
(broad), 1H, CH(CH3)2eNH(2,6-i-Pr2C6H3)), 2.85 (sept (broad), 1H,
CH(CH3)2eNH(2,6-i-Pr2C6H3)), 3.27 (sept, 2H, CH(CH3)2eCH]
N(2,6-i-Pr2C6H3)), 3.48 (s (broad), 1H, NH(2,6-i-Pr2C6H3)), 4.25 and
4.48 (AX system, 2H, NCH2), 6.77 (t,1H, (2,6-i-Pr2C6H3)), 6.88 (d, 2H,
(2,6-i-Pr2C6H3)), 6.98 (m, 2H, C6H4 and NH(2,6-i-Pr2C6H3)), 7.10 (m,
5H, C6H4 and NH(2,6-i-Pr2C6H3)), 7.21 (d, 1H, C6H4), 7.31 (dd, 1H,
C6H4), 7.36 (d, 1H, C6H4), 7.95 (s, 1H, CH]N(2,6-i-Pr2C6H3)), 9.13 (d,
[CF3]ꢀ (4%). IR (cmꢀ1): 3356m
n
(NH), 1703s na(CO2), 1191vs, 1143s
(CF). IR spectrum of single-crystals of 6a: 3357w (NH), 3196m
(OH), 1705m, 1678s nas(CO2), 1192s, 1148s (CF).
n
n
n
n
4.3.4. {2-[CH]N(20,60-i-Pr2C6H3)]C6H4}Sb(CF3SO3)[{2-
[CH2NH(20,60-i-Pr2C6H3)]C6H4} (7)
Compound
CF3SO3H (17
Yield of 7 0.122 g, 77%; m.p. 191e192 ꢁC. 1H NMR (400 MHz, C6D6,
25 ꢁC):
¼ 0.38 (d (broad), 3H, CH(CH3)2), 0.93 (d (broad), 3H,
7
was prepared analogously to compound 4.
1H, C6H4) ppm. 13C NMR (100.61 MHz, C6D6, 25 ꢁC):
d
¼ 25.0, 25.1,
mL, 0.20 mmol); compound 3 (0.130 g, 0.20 mmol).
28.6 (s, CH(CH3)2 and CH(CH3)2), 58.9 (s, NCH2), 124.2, 124.3, 124.7,
127.5, 128.9, 129.8, 129.9, 130.0, 133.2, 133.9, 135.5, 138.3, 140.1,
140.7, 142.7, 144.0, 144.3, 144.9, 147.9, 152.3 (s, C6H4), 169.4 (s, CH]
d
CH(CH3)2), 1.00 (d (broad), 6H, CH(CH3)2), 1.11 (d (broad), 12H,
CH(CH3)2), 1.84 (sept, 1H, CH(CH3)2eNH(2,6-i-Pr2C6H3)), 2.72 (sept,
2H, CH(CH3)2eCH]N(2,6-i-Pr2C6H3)), 2.99 (sept, 1H, CH(CH3)2e
NH(2,6-i-Pr2C6H3)), 4.23 and 4.40 (AX system, 2H, NCH2), 7.06e7.26
(m, 10H, C6H4, NH(2,6-i-Pr2C6H3) and (2,6-i-Pr2C6H3)), 7.73 (dd, 1H,
C6H4), 7.74 (dd,1H, C6H4), 7.90 (dd,1H, C6H4), 7.99 (d,1H, C6H4), 8.53
(d, 1H, C6H4), 8.61 (s, 1H, CH]N(2,6-i-Pr2C6H3)). Anal. calcd for
N(2,6-i-Pr2C6H3)). Anal. calcd for C38H46N2SbCl (688.05 g molꢀ1
)
66.3, H 6.7; Found C 66.6, H 6.9. ESIeMS: Positive mode e m/z 651
[MeCl]þ (100%); m/z 649 [MeCleH2]þ (29%). IR (cmꢀ1): 3354w
n
(NH).
4.3.2. {2-[CH]N(20,60-i-Pr2C6H3)]C6H4}Sb(CH3COO)[{2-
[CH2NH(20,60-i-Pr2C6H3)]C6H4} (5)
C
39H46N2SbO3SF3 (801.68 g molꢀ1) C 58.4, H 5.8; Found C 58.7, H
Compound 5 was prepared analogously to compound 4.
5.9. ESIeMS: Positive mode e m/z 651 [M-CF3SO3]þ (100%). Nega-
tive mode e m/z 149 [CF3SO3]ꢀ (100%). ESIeMS: Positive mode e m/
z 651 [M-CF3SO3]þ (100%). Negative mode e m/z 149 [CF3SO3]ꢀ
CH3COOH (21
Yield of 5 0.227 g, 87%; m.p. 182e183 ꢁC. 1H NMR (400 MHz,
C6D6, 25 ꢁC):
mL, 0.37 mmol); compound 3 (0.239 g, 0.37 mmol).
d
¼ 0.72 (d (broad), 6H, CH(CH3)2), 0.91 (d, 6H,
(100%). IR (cmꢀ1): 3354w
n(CF), 1023s ns(SO3).
n(NH), 1306vs na(SO3), 1231s, 1212vs
CH(CH3)2), 1.23 (d, 6H, CH(CH3)2), 1.33 (d, 6H, CH(CH3)2), 1.92 (s,
3H, CH3CO2), 3.48 (sept, 2H, CH(CH3)2), 4.12 (s (broad), 1H,
NH(2,6-i-Pr2C6H3)), 4.13 and 4.65 (AX system, 2H, NCH2), 6.83e
7.12 (m, 10H, C6H4, NH(2,6-i-Pr2C6H3) and (2,6-i-Pr2C6H3)), 7.37
(m, 2H, C6H4), 7.49 (dd, 1H, C6H4), 7.96 (s, 1H, CH]N(2,6-i-
Pr2C6H3)), 8.70 (d, 1H, C6H4). 13C NMR (100.61 MHz, C6D6, 25 ꢁC):
4.3.5. {2-[CH]N(20,60-i-Pr2C6H3)]C6H4}Sb(FcCOO)[{2-
[CH2NH(20,60-i-Pr2C6H3)]C6H4} (8)
The suspension of compound 3 (0.235 g, 0.36 mmol) in hexane
(15 mL) was added to the suspension of FcCOOH (0.083 g,
0.36 mmol) in hexane (10 mL). The resulting mixture was stirred for
an additional 1 h at room temperature. Evaporation of mixture gave
8. The resulting orange powder was washed with hexane (5 mL) to
give 8. Yield 0.259 g, 82%; m.p. 168e169 ꢁC. 1H NMR (400 MHz,
d
¼ 22.9, 24.9, 25.2, 28.8 (s, CH(CH3)2 and CH(CH3)2), 28.5 (s,
CH3CO), 58.7 (s, NCH2), 124.1, 124.2, 124.4, 127.2, 128.5, 129.5,
129.6, 129.7, 133.2, 133.3, 135.0, 137.5, 140.0, 140.4, 143.3, 144.5,
144.9, 146.1, 147.9, 152.7 (s, C6H4), 168.4 (s, CH]N(2,6-i-Pr2C6H3)),
176.3 (s, CH3C]O). Anal. calcd for C40H49N2SbO2 (711.65 g molꢀ1
)
C6D6, 25 ꢁC):
d
¼ 0.75 (m (broad), 12H, CH(CH3)2), 1.30 (d, 6H,
C 67.5, H 6.9; Found C 67.5, H 7.2. ESIeMS: Positive mode e m/z
749 [M þ K]þ (17%); m/z 733 [M þ Na]þ (7%); m/z 651 [M-
CH3COO]þ (100%); m/z 649 [MeCH3COOeH2]þ (45%). IR (cmꢀ1):
CH(CH3)2), 1.39 (d, 6H, CH(CH3)2), 1.85 (sept (broad), 1H, CH(CH3)2e
NH(2,6-i-Pr2C6H3)), 3.13 (sept (broad), 1H, CH(CH3)2eNH(2,6-i-
Pr2C6H3)), 3.62 (sept, 2H, CH(CH3)2eCH]N(2,6-i-Pr2C6H3)), 3.91 (s,
5H, Cp), 3.98 and 4.79 (AX system, 2H, NCH2), 4.02 (s, 1H, NH(2,6-i-
3344w n(NH), 1636s na(CO2).

I. Urbanová et al. / Journal of Organometallic Chemistry 743 (2013) 156e162
161
Table 1
Crystallographic data for 3, 5, 6a and 7a.
3
5
6a
7a
Empirical formula
C38H44BiClN2
C40H49N2O2Sb
C40H46F3N2O2Sb.C2HF3O2
C39H47F3N2O3SSb.CF3O3S
0.5(C6H6)
Triclinic
P ꢀ 1
Cryst syst
Triclinic
P ꢀ 1
Monoclinic
Cc
9.9333(5)
22.7440(3)
16.8212(4)
90
105.861(3)
90
4
Triclinic
P ꢀ 1
Space group
ꢁ
a [A]
11.6330(9)
12.5511(11)
13.1690(9)
90.218(6)
109.429(6)
103.405(5)
2
10.8670(12)
11.9320(7)
17.3081(14)
71.076(5)
85.882(6)
77.799(6)
2
10.6460(9)
12.2800(9)
20.1551(12)
80.908(5)
75.679(6)
64.477(6)
2
ꢁ
b [A]
ꢁ
c [A]
a
b
g
Z
m
[ꢁ]
[ꢁ]
[ꢁ]
[mmꢀ1
]
5.120
1.461
0.789
1.293
0.734
1.408
0.761
1.431
Dx [Mg mꢀ3
]
Cryst size [mm]
q
0.35 ꢂ 0.34 ꢂ 0.23
0.25 ꢂ 0.25 ꢂ 0.18
1e27.5
0.869, 0.912
26 002
7901, 0.050
6938
0.40 ꢂ 0.13 ꢂ 0.08
0.30 ꢂ 0.21 ꢂ 0.15
range, [ꢁ]
1e27.5
1e27.5
1e27.5
Tmin, Tmax
No. of reflections measured
No. of unique reflns, Rint
No. of observed reflns [I > 2s(I)]
0.869, 0.912
33 109
8055, 0.045
7121
0.846, 0.957
37 192
9390, 0.060
7483
0.875, 0.946
48 248
10 478, 0.043
8734
a
No. of parameters
398
1.118
0.030
0.061
406
1.110
0.036
0.058
496
1.090
0.049
0.090
518
1.112
0.045
0.083
S
b all data
Final Rb indices [I > 2
s
(I)]
wR2b indices (all data)
Dr, max., min. [e A
ꢁꢀ3
]
1.519, ꢀ1.173
0.532, ꢀ0.340
1.223, ꢀ0.788
0.490, ꢀ0.504
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
P
P
a
Rint
¼
F2 ꢀ Fo2;mean
=
Fo2
.
o
P
1
P
P
P
P
1
2
S ¼ ½ ðwðFo2 ꢀ Fc2Þ2Þ=ðNdiffrs ꢀ NparamsÞꢃ , RðFÞ ¼ jjFoj ꢀ j:Fcj:j= jFoj; wRðF2Þ ¼ ½ ðwðFo2 ꢀ Fc2Þ2Þ= wðFo2Þ2ꢃ
.
b
2
Pr2C6H3)), 4.05 (m, 1H, Cp(COO)Fe), 4.09 (m, 1H, Cp(COO)), 4.93 (m,
1H, Cp(COO)Fe), 4.96 (m, 1H, Cp(COO)Fe), 6.86e7.02 (m, 8H, C6H4,
NH(2,6-i-Pr2C6H3) and CH]N(2,6-i-Pr2C6H3)), 7.20 (m, 2H, C6H4),
7.52 (m, 2H, C6H4), 7.58 (d, 1H, C6H4), 7.98 (s, 1H, CH]N(2,6-i-
Pr2C6H3)), 8.99 (d, 1H, C6H4). 13C NMR (100.61 MHz, C6D6, 25 ꢁC):
correct the data for the presence of disordered solvent. A potential
3
ꢁ
solvent volume of 194 A was found. 40 electrons per unit cell
worth of scattering were located in the void. The calculated stoi-
chiometry of solvent was calculated to be one molecule of benzene
per unit cell which results in 42 electrons per unit cell. The crys-
tallographic data are summarized in Table 1.
d
¼ 25.3 and 28.2 (s, CH(CH3)2 and CH(CH3)2), 59.1 (s, NCH2), 70.2,
70.9, 71.1, 71.2, 71.4 (s, Cp and Cp(COO)), 75.8 (s, Cp(COO)-ipso),
124.1, 124.2, 124.3, 127.2, 128.8, 129.6, 129.8, 129.9, 133.2, 133.4,
134.7, 137.6, 140.0, 140.4, 143.2, 144.8, 145.0, 146.5, 148.0, 153.1 (s,
C6H4), 168.4 (s, CH]N(2,6-i-Pr2C6H3)), 175.8 (s, C]O). Anal. calcd
for C49H55N2SbO2Fe (881.65 g molꢀ1) C 66.8, H 6.3; Found C 66.9, H
6.5. ESI/MS: Positive mode e m/z 919 [M þ K]þ (56%); m/z 651 [M-
Acknowledgements
The authors wish to thank the Faculty of Chemical Technology of
the University of Pardubice for continuous financial support.
Fe(Cp)2COO]þ (100%). IR (cmꢀ1): 3357m
n(NH), 1626s nas(CO2).
Appendix A. Supplementary material
4.4. X-ray structure determination
4.4.1. Crystallography
CCDC 932689, 932690, 932691 and 932692 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.
The X-ray data for colourless crystals of 3, 5, 6a and 7a were
obtained at 150 K using Oxford Cryostream low-temperature de-
vice on a Nonius KappaCCD diffractometer with Mo Ka radiation
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