Binucleating aza-sulfonate and aza-sulfinate macrocycles - Synthesis and coordination chemistry

Article abstract of DOI:10.1002/ejic.200400460

The preparation and ligating properties of S-oxygenated derivatives of a macrobinucleating hexaazadithiophenolate macrocycle H₂L¹ of the Robson type towards nickel(II) and zinc(II) ions are reported. Nickel complexes of the hexaazadiphenylsulfonate ligand (L²)^2- [(L²)Ni^II₂(μ-L)]⁺ (L = m-Cl-OBz^- (3), Cl^- (4) and OAc^- (6)] are readily obtained in high yields by oxidation of the respective [(L ¹)Ni^II₂(μ-L)]⁺ parent complexes [L = m-Cl-OBz^- (2), Cl^- (1), OAc^- (5)] with meta-chloroperoxybenzoic acid or hydrogen peroxide. Decomposition of the sulfonate complexes gives the free macrocycle H₂L² which, upon treatment with Zn(OAc)₂·2H₂O, produces the diamagnetic zinc complex [(L²)Zn^II₂(OAc)] ⁺ (8). A dinuclear Cu^II complex of the hexaazadisulfinate derivative (L³)^2-, [(L³)Cu^II ₂]²⁺ (9), is formed rather unexpectedly by air oxidation of (L¹)^2- in the presence of Cu^I. The crystal-structure determinations of the perchlorate or tetraphenylborate salts of 2,3, and 4 show that the new ligands support the formation of binuclear complexes with bowl-shaped, calixarene-like binding cavities. NMR spectroscopic studies of 8 show that the complexes retain their solid-state structures in solution. A crystal-structure determination of 9 reveals two five-coordinate Cu^II ions bridged by the two sulfinate functions of (L ³)^2-. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.

Full text of DOI:10.1002/ejic.200400460

FULL PAPER
Binucleating Aza-Sulfonate and Aza-Sulfinate Macrocycles — Synthesis and
Coordination Chemistry
Julia Hausmann,[a][‡] Steffen Käss,[a] Sabrina Klod,[b] Erich Kleinpeter,[b] and
Berthold Kersting*[a]
Keywords: Cavitands / Macrocyclic ligands / Nickel / S ligands
2+
The preparation and ligating properties of S-oxygenated de-
[(L3)CuII
]
(9), is formed rather unexpectedly by air oxida-
2
rivatives of
a
macrobinucleating hexaazadithiophenolate
tion of (L1)2− in the presence of CuI. The crystal-structure de-
macrocycle H2L1 of the Robson type towards nickel(II) and terminations of the perchlorate or tetraphenylborate salts of
zinc(II) ions are reported. Nickel complexes of the hexaazadi- 2, 3, and 4 show that the new ligands support the formation
phenylsulfonate ligand (L2)2− [(L2)NiII2(µ-L)]+ (L = m-Cl-OBz−
(3), Cl− (4) and OAc− (6)] are readily obtained in high yields
by oxidation of the respective [(L1)NiII2(µ-L)]+ parent comple-
of binuclear complexes with bowl-shaped, calixarene-like
binding cavities. NMR spectroscopic studies of 8 show that
the complexes retain their solid-state structures in solution.
xes [L = m-Cl-OBz− (2), Cl− (1), OAc− (5)] with meta-chloro- A crystal-structure determination of 9 reveals two five-coor-
peroxybenzoic acid or hydrogen peroxide. Decomposition of
the sulfonate complexes gives the free macrocycle H2L2
which, upon treatment with Zn(OAc)2·2H2O, produces the
diamagnetic zinc complex [(L2)ZnII2(OAc)]+ (8). A dinuclear
dinate CuII ions bridged by the two sulfinate functions of
(L3)2−
.
( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2004)
CuII complex of the hexaazadisulfinate derivative (L3Ј)2−
,
Introduction
species.[24] The unique features of the corresponding com-
plexes[25] led us to investigate potential routes to S-oxygen-
ated derivatives of H2L1 and to examine the ligating proper-
ties of these hitherto unknown ligand systems (Scheme 1).
Herein we report the synthesis of the binucleating hexaaza-
sulfonate ligand (L2)2Ϫ and demonstrate its ability to form
dinuclear transition-metal complexes with bowl-shaped
binding cavities. The synthesis and crystal structure of a
dinuclear copper() complex of the related hexaazasulfinate
ligand (L3)2Ϫ are also reported.
The development of ligand systems that support the for-
mation of metal complexes with confined environments
about active coordination sites is currently attracting much
interest.[1Ϫ3] This is mainly due to the fact that such as-
semblies improve the ability to control the rate and selec-
tivity of substrate transformations.[4Ϫ8] Such aggregates
also allow for the construction of more-effective enzyme
mimics.[9] Consequently, a large number of bowl-shaped
supporting ligands have been reported and their ligating
properties towards the 3d elements have been investigated.
While most of these ligands form mononuclear complexes,
as, for instance, the calixarenes,[10] the cyclodextrins,[11] and
some tripod ligands,[12Ϫ14] there are only a few reports of
ligand systems that impose calixarene-like structures about
dinuclear cores.[15Ϫ17] We have recently shown that N-func-
tionalized hexaazadithiophenolate macrocycles[18,19] of the
Robson type[20Ϫ23] are suitable for the construction of such
[a]
Institut für Anorganische und Analytische Chemie,
Universität Freiburg
Scheme 1. Structures of the ligands H2L1, H2L2 and H2L3 (see
Scheme 2 for numbering of complexes)
Albertstr. 21, 79104 Freiburg, Germany
Fax: (internat.) ϩ 49-761-203-5987
E-mail: berthold.kersting@ac.uni-freiburg.de
[b]
Institut für Chemie, Universität Potsdam
Results and Discussion
The compounds synthesized in this paper are collected in
Scheme 2. Of these, the nickel and zinc complexes 1, 5, and
7 have been reported previously.
P. O. Box 601553, 14415 Potsdam, Germany
[‡]
Present address: Department of Chemistry, University of Otago
P. O. Box 56, Dunedin, New Zealand
Supporting information for this article is available on the
WWW under http://www.eurjic.org or from the author.
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DOI: 10.1002/ejic.200400460
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Binucleating Aza-Sulfonate and Aza-Sulfinate Macrocycles
FULL PAPER
MCPBA was expected to give the µ-Cl compound 4, but
the infrared spectrum (vide infra) revealed the presence of
the µ-meta-chlorobenzoate-containing complex 3, showing
that this transformation is accompanied by a substitution
of the bridging chloride ion by the meta-chlorobenzoate
group (which is produced upon reduction of MCPBA). In
contrast, the oxidation of 5 yields the acetato-bridged com-
plex 6 as the sole product. Thus, in this case an exchange
of the encapsulated acetate moiety by the external meta-
chlorobenzoate does not occur, despite it being present in a
sixfold molar excess.
In the course of our work it was found that the aminosul-
fonate complexes 3 and 6 can also be prepared by oxidation
of their respective parent complexes with hydrogen peroxide
(Scheme 3). This prompted us to test whether complex 4
would be similarly accessible by H2O2 oxidation of 1. In-
deed, treatment of 1 with a large excess of H2O2 resulted in
the formation of a pale-green solution, from which the de-
sired µ-chloro complex 4·ClO4 could be obtained upon ad-
dition of an excess of LiClO4. Nevertheless, the thiolate
complexes are very resistant towards oxidation by H2O2. In
the case of 2 and 5, for example, a large excess and pro-
longed heating was required to obtain the respective oxi-
dation products 3 and 6 in good yields.
Scheme 2. Synthesized complexes and their labels (see Scheme 1
and ref. 31 for ligand abbreviations)
Attempts to S-oxygenate the free hexaazadithiophenol
H2L1 invariably proved unsuccessful, presumably due to the
formation of amine N-oxides. The oxidation of dinickel
complexes of (L1)2Ϫ was attempted next, since this has re-
cently been demonstrated to be a versatile method for the
preparation of sulfonate complexes,[26] even for complexes
of labile transition-metal ions such as nickel().[27Ϫ29] In a
preliminary experiment the meta-chlorobenzoato-bridged
species 2[30] was treated with six equivalents of meta-chloro-
peroxybenzoic acid (MCPBA) at 0 °C (Scheme 3).[31] This
resulted in the rapid and almost quantitative formation of
the desired aminosulfonate complex 3. The facile formation
of 3 is somewhat remarkable given that S-oxygenation of
bridging thiolate functions has not been observed pre-
viously in nickel thiolate chemistry.[32,33]
As noted above, the direct oxidation of H2L1 failed to
provide the macrocyclic hexaazadisulfonic acid H2L2, and
so another route had to be developed. We have previously
observed that binuclear complexes of the aminothiolate li-
gand (L1)2Ϫ decompose under acidic conditions to give the
free aminothiol H2L1 as its hexahydrochloride salt.[34] Ac-
cordingly, the decomposition of the perchlorate salt 3·ClO4
with hydrochloric acid was attempted (Scheme 4). The ami-
nosulfonate complex was found to be very stable under
acidic conditions, but with concentrated hydrochloric acid
complete hydrolysis occurred, such that the desired ligand
H2L2·6HCl could be isolated in good yields. The identity of
1
H2L2·6HCl was confirmed by IR, H and 13C NMR spec-
troscopy (see below), and by the successful regeneration of
complex 6. Thus, treatment of H2L2·6HCl with two equiva-
lents of Ni(OAc)2·6H2O resulted in a pale-green solution,
from which the known complex 6·ClO4 could be isolated in
excellent yields upon addition of LiClO4.
Scheme 4. Synthesis of compounds H2L2·6HCl and 6
In order to get some preliminary information on the solu-
tion structures of the new complexes, the synthesis of dia-
magnetic zinc complexes was devised. The acetato-bridged
Scheme 3. Synthesis of compounds 2Ϫ6
In light of these results the oxidation of the chloro- and dizinc complex 8 was selected as the target compound. All
acetato-bridged species 1 and 5, respectively, was examined attempts to access 8 by oxidation of its parent complex 7
next (Scheme 3). The oxidation of the chloro complex 1 by were unsuccessful, but, similar to 6·ClO4, this complex
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J. Hausmann, S. Käss, S. Klod, E. Kleinpeter, B. Kersting
FULL PAPER
could be readily prepared by the complexation of the free 2·BPh4·1.25MeCN, 3·BPh4·4EtOH·2H2O, 4·BPh4·EtOH·
macrocycle with Zn(OAc)2·2H2O (Scheme 5). Thus, the re- 0.5CH3CN, and 9·(ClO4)2·H2O also by X-ray structure
action of H2L2·6HCl with two equivalents of analysis.
Zn(OAc)2·2H2O resulted in a colourless solution, from
which the colourless perchlorate salt [(L2)Zn2(µ-OAc)]ClO4
(8·ClO4) was obtained in the form of large crystals in nearly
quantitative yield upon addition of LiClO4.
Infrared and UV/Vis Spectroscopy
Table 1 summarizes selected analytical data for com-
pounds 1Ϫ9. In agreement with the formulation of 3 the
IR spectrum displays a strong band at 1220 cmϪ1 for the
Ϫ [35]
sulfonate group ν(RSO3
)
and two absorptions at 1563
[νas(RCO2Ϫ)] and 1410 cmϪ1 [νs(RCO2Ϫ)] for the meta-
chlorobenzoate coligand.[36] The latter two values are very
similar to those of the parent complex 2, suggesting that the
meta-chlorobenzoate moiety in 3 is also in the µ1,3-bridging
mode. Similarly, the IR spectrum of the acetato-bridged
complex 6 shows distinct IR bands for bridging acetate
(1597 and 1411 cmϪ1) and sulfonate groups (1202 cmϪ1).
Scheme 5. Synthesis of compounds 8 and 9
Unfortunately, the sulfonate stretching frequencies overlap
2ϩ
Finally, we were also able to prepare a dinuclear complex with the bands of the [(L2)NiII
]
fragment[37] and the
2
of the aminosulfinate ligand (L3)2Ϫ, the dicopper() com- counterions (ClO4 or BPh4Ϫ), such that the coordination
plex 9. This complex was obtained rather unexpectedly mode of the RSO3 functions could not be deduced from
Ϫ
Ϫ
from attempts to prepare mixed-valent CuICuII complexes the IR data. The IR spectra of the homologous nickel and
of (L1)2Ϫ. Attempts to access this compound by air oxi- zinc complexes 5 and 7 (and 6 and 8) are identical. Finally,
dation of a methanolic solution of the dicopper() complex the IR spectrum of the copper complex 9 shows two ab-
[(L1)CuI2]2Ϫ (prepared in situ from H2L1, [CuI- sorptions at 1052 and 950 cmϪ1, which can be attributed to
(CH3CN)4](ClO4) and NEt3), however, resulted in the for- the stretching frequencies of the sulfinate functions.[38]
mation of the sulfinate complex 9 instead. The dark-green Again, the coordination mode of the sulfinate groups could
perchlorate salt [(L3)CuII2](ClO4)2 [9·(ClO4)2] was reprodu- not be inferred from the IR data.
cibly obtained as a dark-green microcrystalline solid in
All new complexes were further characterized by UV/Vis
about 45% yield.
spectroscopy. The UV/Vis data of 1, 2 and 5 have been re-
All new complexes are stable in air, both in solution and ported previously.[24,25] The electronic absorption spectra of
in the solid state. The perchlorate salts are very soluble in the new complexes were recorded in the range
a range of common organic solvents. The solubility of the 300Ϫ1600 nm in acetonitrile solution at ambient tempera-
complexes of the hexaazadisulfonate macrocycle is particu- ture (Table 1). The spectra of the pale-green nickel com-
larly good in polar protic solvents such as ethanol, meth- plexes 3, 4, and 6 are similar but not identical. In agreement
anol, and even 25% aqueous methanol. In contrast to the with the oxidation of the thiophenolate sulfur atoms, there
aminothiolate complexes, the sulfonate complexes are stable are no intense RSϪǞNiII charge-transfer transitions in the
over a wide pH range. They can be isolated from acidic or 300 to 400 nm region.[39] Each compound displays three
basic methanolic solution (pH 1 to 10) without any notice- weak absorption bands. The first band is seen around
able decomposition or exchange of the bridging coligands 400 nm, the second one appears in the 670 to 690 nm range,
L. The new compounds gave satisfactory elemental analyses and the third one is observed between 1120 and 1130 nm.
and were characterized by spectroscopic methods (IR, UV/ These absorptions can be attributed to the three spin-al-
3
Vis, 1H and 13C NMR spectroscopy) and compounds lowed d-d-transitions ν3 [3A2g(F) Ǟ T1g(P)], ν2 [3A2g(F) Ǟ
Table 1. Selected analytical data of compounds 2؊9[a]
Compound
IR bands (cmϪ1) and assignments
UV/Vis λmax [nm] (ε [Ϫ1·cmϪ1])
1
390 (2830), 625 (58), 941 (56)[b]
385 (2400), 651 (26), 1116 (65)
400 (47), 674 (14), 1126(15)
396 (33), 686 (15), 1124 (17)
395 (2640), 649 (28), 1134(55)[c]
398 (55), 670 (25), 1122 (47)
Ϫ
2
1566, 1423; νas, νs(RCO2 )
Ϫ
Ϫ
Ϫ
3
1563, 1410; νas, νs(RCO2Ϫ); 1220 νs(RSO3
)
)
)
Ϫ
4
1202, νs(RSO3 )
Ϫ [c]
5
1588, 1426; νas, νs(RCO2 )
6
1597, 1411; νas, νs(RCO2Ϫ); 1202 νs(RSO3
H2LMeЈ·6HCl
1228, ν(RSO3 H)
Ϫ [c]
7
8
9
1585, 1428; νas, νs(RCO2 )
1595, 1411; νas, νs(RCO2Ϫ); 1202 νs(RSO3
Ϫ
1052, 950; νs(RSO2
)
668 (430), 947 (153)
[a]
Ϫ
Ϫ
[b]
The complexes were isolated as their ClO4 or BPh4 salts. Ref.[24a] [c] Ref.[25]
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Binucleating Aza-Sulfonate and Aza-Sulfinate Macrocycles
3
FULL PAPER
3T1g(F)], and ν1 [3A2g(F) Ǟ T2g(F)], respectively, of an oc- preliminary chemical shielding calculations using Gaussian
tahedral d8 nickel() ion. The higher energy features below 98 (∆δcalc ϭ Ϫ1.92 ppm for 8 vs. Ϫ1.25 ppm for 7; see Exp.
300 nm result from π-π* transitions within the (L2)2Ϫ li- Sect. for details).
gand. The slight differences in the position of the d-d tran-
X-ray Crystallography
sitions indicate that each complex retains its coligand in the
solution state. Finally, the dark-green dicopper() complex
displays a single absorption band at 668 nm. This is a typi-
cal value for square-pyramidal CuIIN3O2 complexes.[40]
Although the formulations of the new compounds were
reasonably substantiated by the above spectroscopic data,
further confirmation was provided by X-ray diffraction
studies. Single crystals of X-ray quality were obtained for
the perchlorate or tetraphenylborate salts of complexes 2,
3, 4, and 9. The crystal structures of complexes 1, 5, and 7
have been reported previously.[24,25] All data collections
were performed at 210 K. A common labeling scheme for
the [(L1)Ni2]2ϩ and [(L2)Ni2]2ϩ units has been used to facili-
tate structural comparisons. Selected bond lengths and
angles are given in Table 2 and 3.
NMR Spectroscopy
To investigate the solution structures, the zinc complex 8
1
was characterized by H and 13C NMR spectroscopy. The
NMR spectroscopic properties of the zinc complex 7 have
been reported previously.[25] The 1H NMR spectrum of 8 in
CD3CN solution displays only one set of signals, indicating
that 8 exists as a single isomer in solution. The four aro-
matic protons, the methyl protons on the benzylic nitrogens,
the methyl protons on the central amine nitrogen of the
linking diethylene triamine units, and the tert-butyl protons
all appear as singlets. This is indicative of a C2v symmetric
solution structure for the [(L2)Zn2(µ-OAc)]ϩ cation. In
agreement with this assumption the [(L2)Zn2]2ϩ fragment
gives rise to only eleven 13C NMR signals (seven for the
aliphatic and four for the aromatic carbon atoms). The ap-
˚
Table 3. Selected bond lengths (A) and angles (°) in complex 9;
symmetry code used to generate equivalent atoms (Ј): Ϫx, Ϫy, Ϫz
Cu(1)ϪO(1)
Cu(1)ϪN(1)
Cu(1)ϪN(3)
S(1)ϪO(2)
2.002(2) Cu(1)ϪO(2Ј)
2.258(3) Cu(1)ϪN(2)
2.041(3) S(1)ϪO(1)
1.510(3) Cu(1)···Cu(1Ј)
1.968(2)
2.056(3)
1.504(2)
4.993(1)
O(2Ј)ϪCu(1)ϪO(1)
95.91(10) O(2Ј)ϪCu(1)ϪN(1) 96.36(11)
88.38(11)
O(1)ϪCu(1)ϪN(3) 154.03(11) N(3)ϪCu(1)ϪN(1) 116.20(12)
1
pearance of a H NMR signal at δ ϭ 0.59 ppm, which can
O(2Ј)ϪCu(1)ϪN(3) 89.81(12) O(1)ϪCu(1)ϪN(1)
be assigned to the methyl protons of the bridging acetate
ion, is worthy of note. The observed high-field shift [8: ∆δ ϭ
Ϫ1.24 ppm, relative to NaOAc (δ ϭ 1.83 ppm)] can be ex-
plained by the ring current. As can be seen from Figure
S1,[41] the methyl protons of the coordinated acetate group
are positioned above the center of the two phenyl rings in
O(2Ј)ϪCu(1)ϪN(2) 175.42(12) N(2)ϪCu(1)ϪN(1)
85.12(13)
109.46(14)
O(1)ϪCu(1)ϪN(2)
N(3)ϪCu(1)ϪN(2)
88.45(12) O(1)ϪS(1)ϪO(2)
85.65(12)
The structure of 2 (Figure 1) reveals the presence of dis-
the shielding region. The angle between the phenyl rings in crete dinuclear [(L1)Ni2(m-Cl-OBz)]ϩ cations, tetraphe-
8 (41.6°)[42] is more acute than in 7 (80.0°) and hence the nylborate anions and acetonitrile molecules of solvent of
shielding effect is less pronounced in the latter (7: ∆δ ϭ crystallization. The macrocycle (L1)2Ϫ adopts a conical ca-
Ϫ0.92 ppm, relative to NaOAc). This is also supported by lixarene-like conformation, which is typical for carboxylato-
˚
Table 2. Selected bond lengths (A) and angles (°) in complexes 2, 3, and 4
2[a]
3
4[a]
Ni(1A)ϪO(1A)
Ni(1A)ϪN(1A)
Ni(1A)ϪN(2A)
Ni(1A)ϪN(3A)
Ni(1A)ϪS(1A)
Ni(1A)ϪS(2A)
Ni(2A)ϪO(2A)
Ni(2A)ϪN(4A)
Ni(2A)ϪN(5A)
Ni(2A)ϪN(6A)
Ni(2A)ϪS(1A)
Ni(2A)ϪS(2A)
NiϪN[b]
2.010(3) [2.028(3)]
2.282(3) [2.281(3)]
2.176(4) [2.158(3)]
2.222(4) [2.239(3)]
2.504(2) [2.512(1)]
2.406(2) [2.396(1)]
2.020(3) [2.016(3)]
2.207(4) [2.216(3)]
2.170(4) [2.172(3)]
2.307(4) [2.311(3)]
2.484(2) [2.501(2)]
2.401(2) [2.398(1)]
2.227(3) [2.230(3)]
2.015(3) [2.022(3)]
2.449(2) [2.451(1)]
9.489 [9.563]
Ni(1)ϪO(1)
Ni(1)ϪN(1)
Ni(1)ϪN(2)
Ni(1)ϪN(3)
Ni(1)ϪO(5)
Ni(1)ϪO(7)
Ni(2)ϪO(2)
Ni(2)ϪN(4)
Ni(2)ϪN(5)
Ni(2)ϪN(6)
Ni(2)ϪO(4)
Ni(2)ϪO(8)
2.111(5)
2.230(7)
2.136(6)
2.265(6)
2.073(5)
2.040(5)
2.102(5)
2.266(6)
2.131(7)
2.254(7)
2.109(5)
2.009(5)
2.214(7)
2.074(5)
Ni(1A)ϪCl(1A)
Ni(1A)ϪN(1A)
Ni(1A)ϪN(2A)
Ni(1A)ϪN(3A)
Ni(1A)ϪO(1A)
Ni(1A)ϪO(4A)
Ni(2A)ϪCl(1A)
Ni(2A)ϪN(4A)
Ni(2A)ϪN(5A)
Ni(2A)ϪN(6A)
Ni(2A)ϪO(2A)
Ni(2A)ϪO(5A)
2.439(1) [2.482(2)]
2.160(4) [2.183(4)]
2.146(4) [2.132(4)]
2.320(4) [2.264(4)]
2.064(3) [2.048(3)]
2.051(3) [2.095(3)]
2.453(1) [2.449(1)]
2.180(4) [2.254(4)]
2.120(4) [2.132(4)]
2.286(4) [2.195(4)]
2.057(3) [2.043(4)]
2.098(3) [2.084(3)]
2.202(4) [2.193(4)]
2.068(3) [2.068(3)]
NiϪO[b]
NiϪS[b]
C(4)···C(20)
7.958
44.5
4.584(2)
9.471 [9.370]
72.2 [69.8]
4.063(2) [4.086(2)]
Ph/Ph[c]
93.6 [92.2]
3.460(1) [3.457(1)]
Ni···Ni
[a] There are two crystallographically independent molecules A and B in the unit cell. Values in square brackets refer to the corresponding
[b]
[c]
bond lengths of the second molecule. Average values. Angle between the normals of the planes of the two aryl rings.
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J. Hausmann, S. Käss, S. Klod, E. Kleinpeter, B. Kersting
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Figure 1. Molecular structure of the cation 2; thermal ellipsoids
are drawn at the 30% probability level; hydrogen atoms are omitted
for clarity.
Figure 2. Molecular structure of the cation 3; thermal ellipsoids
are drawn at the 30% probability level; hydrogen atoms are omitted
for clarity
bridged complexes of this ligand.[43] In this approximately
C2v-symmetric structure, the two nickel() ions are coordi- tertiary butyl groups of (L2)2Ϫ, as evidenced by a very short
˚
nated in a square-pyramidal fashion by the two fac-N3(µ- C(4)···C(20) distance of 7.958 A. The short distances be-
S)2 donor sets of the macrocycle. Upon coordination of the tween the coligand and the tBu protons [H(37a)···C(43)
˚
˚
meta-chlorobenzoate group, both nickel atoms reach dis- 3.230 A; H(34c)···C(43) 3.311 A] are indicative of intra-
torted octahedral coordination environments at
a
molecular van der Waals interactions between the host and
˚
metalϪmetal distance of 3.460(1) A. As in previously re- its guest. This is also supported by the wider binding pocket
ported carboxylato-bridged nickel complexes of (L1)2Ϫ, the in the µ-Cl species 4 (see below).
NiϪN bond lengths involving the four benzylic nitrogen
Crystals of 4·BPh4·EtOH·0.5CH3CN are composed of
donors are invariably longer (by ca. 0.10Ϫ0.12 A) than the discrete, dinuclear [(L2)Ni2(µ-Cl)]ϩ cations, tetraphenylbo-
ones comprising the central nitrogen atoms of the linking rate anions and ethanol and acetonitrile molecules of sol-
diethylenetriamine units. The individual NiϪS distances vent of crystallization (see Figure 3). Similar to 3, the ami-
also vary considerably. These distortions are almost cer- nosulfonate ligand in 4 assumes a calixarene-like confor-
tainly a consequence of the steric constraints of the macro- mation such that the bridging halide ion is deeply buried in
˚
cycle.
the binding cavity of the [(L2)Ni2]2ϩ fragment. This ligand
The dimensions of the bowl-shaped binding cavity of the conformation is different from the ‘‘partial cone’’-like con-
[(L1)Ni2]2ϩ fragment can be described by the intramolecu- formation seen in its parent 1.[24] The corresponding NiϪO
lar distance between the two opposing aryl ring carbon and NiϪN bond lengths in 3 and 4, respectively, are very
atoms C(4) and C(20) and by the angle between the planes similar. In both structures the NiϪN bond lengths involv-
through the phenyl rings. For the present structure, the cor- ing the four benzylic nitrogen donors are invariably longer
˚
˚
responding values are 9.489(1) A and 93.6°, respectively. As (by ca. 0.1 A) than the ones comprising the central nitrogen
we will show below, these values decrease considerably atoms of the linking diethylenetriamine units; the NiϪO
upon oxygenation of the thiophenolate sulfur atoms.
distances also vary considerably. These distortions can be
The crystal-structure determination of 3·BPh4 unambigu- traced back to the steric constraints of the macrocycle. The
ously confirmed 3 to be a bioctahedral dinickel complex of main differences between the structures of 3 and 4 concern
the new hexaazadiphenylsulfonate ligand (L2)2Ϫ (see Fig- the Ni···Ni distances (4.063 A in 4, 4.584 A in 3) and the
ure 2). The two sulfonate groups and the meta-chlorobenzo- angle between the phenyl rings (72.2° in 4, 44.5° in 3). While
ate ion bridge the two NiII ions in symmetrical µ1,3-modes, the differences in the Ni···Ni distances can be traced back
˚
˚
2 2Ϫ
˚
at a distance of 4.584(1) A. The amine nitrogens of (L )
to the different ligating properties of the coligands, the
occupy the remaining positions and complete the pseudo- more pronounced clipping of the phenyl rings in 3 is pre-
octahedral N3O3 coordination spheres of the metal ions. sumably due to attractive van der Waals interactions be-
Ϫ
Precedents for this type of µ1,3-bridging RSO3 functions tween the apolar CH function of the bowl-shaped host and
exist in the literature,[44] albeit not incorporated into a mac- its guest. Such secondary interactions are of importance as
robinucleating ligand. A comparison with the structure of they can confer unusual binding modes on the coligands.[45]
the parent complex 2 reveals a significant compression of
the binding pocket. Thus, in 3 the best planes through the 9·(ClO4)2·H2O reveals the dication 9 to be a dicopper()
phenyl rings intersect at an angle of 44.6°. This value is complex of the new hexaazadiphenylsulfinate ligand (L3)2Ϫ
Finally, the crystal structure determination of
.
much more acute than in 2 (93.6°). As a consequence the The complex dication exhibits a center of inversion such
meta-chlorobenzoate ion becomes tightly embraced by the that the asymmetric unit consists of only one half of the
4406
 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
Eur. J. Inorg. Chem. 2004, 4402Ϫ4411

Binucleating Aza-Sulfonate and Aza-Sulfinate Macrocycles
FULL PAPER
Conclusion
The main findings of the present work can be summar-
ized as follows: a) S-oxygenated derivatives of binucleating
hexaazadithiophenolate macrocycles of the Robson type
can be readily prepared by oxidation of dinuclear nickel
complexes of the parent hexaazadithiophenolate macro-
cycles followed by decomposition of the oxidation products
in acidic solution. b) The new hexaazadisulfonate macrocy-
cle (L2)2Ϫ is an effective dinucleating ligand that supports
the formation of dinuclear complexes of the type [(L2)M2(µ-
L)]ϩ with a bowl-shaped, calixarene-like structure. c) The
[(L2)M2]2ϩ fragment is capable of binding different col-
igands. d) The [(L2)M2(µ-L)]ϩ complexes retain their solid-
state structures in the solution state. e) The more pro-
nounced clipping of the phenyl rings in the [(L2)M2(µ-L)]ϩ
complexes is presumably due to attractive van der Waals
interactions between the ligand matrix of the complex and
the encapsulated coligand. f) The sulfonate complexes are
stable over a wider pH range and oxidizing conditions.
Thus, the reactivity of the encapsulated coligands can now
also be examined under these more forcing conditions.
Experimental Section
Figure 3. Two views of the molecular structure of the cation 4;
thermal ellipsoids are drawn at the 30% probability level; hydrogen
atoms are omitted for clarity
General: Unless otherwise noted the preparations of the metal com-
plexes were carried out under an argon atmosphere by using stand-
ard Schlenk techniques. The compounds H2L1·6HCl,
[(L1)Ni2(Cl)]ClO4 (1·ClO4), [(L1)Ni2(OAc)]ClO4 (5·ClO4), and
[(L1)Zn2(OAc)]ClO4 (7·ClO4) were prepared as described in the lit-
erature.[25] All other compounds and reagents were purchased from
Aldrich. Melting points were determined in capillaries and are un-
corrected. 1H and 13C NMR spectra were recorded on a Bruker
AVANCE DPX-200 or a Varian 300 unity spectrometer. Elemental
analyses were performed on a Vario EL analyzer (Elementaranaly-
sensysteme GmbH). All compounds crystallize with solvent mol-
ecules (see crystal structures of 3·BPh4·2EtOH·0.5CH3CN and
4·BPh4·2EtOH·0.5CH3CN), but the compounds slowly lose their
solvent molecules of crystallization upon standing in air. This is
why the observed microanalytical data do not fit exactly with the
calculated values (for the solvent-free compounds). IR spectra were
recorded on a Bruker VECTOR 22 FT-IR spectrophotometer as
KBr pellets. Electronic absorption spectra were recorded on a Jasco
V-570 UV/Vis/near IR spectrophotometer.
formula unit. As can be seen from Figure 4 the two sulfin-
ate functions bridge the two CuII ions in symmetrical µ1,3
-
˚
modes, at a Cu···Cu distance of 4.993(1) A. The amine ni-
trogens of (L3)2Ϫ occupy the remaining positions and com-
plete the pseudo-square-pyramidal N3O2 coordination
spheres of the metal ions. The mean CuϪN and CuϪO
˚
distances of 2.118 and 1.985 A show no unusual features
and compare well with those in related CuIIN3O2 com-
plexes.[46]
Safety note! Perchlorate salts of transition-metal complexes are haz-
ardous and may explode. Only small quantities should be prepared
and great care taken. We have not encountered any problems with
the ClO4 salts of the present complexes (hammer test), and have for
this reason not prepared the BF4 complexes.
[(L1)NiII2(m-Cl-OBz)]ClO4 (2·ClO4): A solution of sodium meta-
chlorobenzoate (26.8 mg, 0.150 mmol) in methanol (5 mL) was ad-
ded to a solution of [(L1)Ni2(Cl)]ClO4 (92 mg, 0.10 mmol) in meth-
anol (30 mL). The mixture was stirred for 2 h, during which time
the color of the solution turned from yellow to pale green. A solu-
tion of LiClO4·3H2O (400 mg, 2.50 mmol) in methanol (2 mL) was
then added. The resulting pale-green microcrystalline solid was iso-
lated by filtration, washed with methanol, and dried in air. This
material was recrystallized once from a mixed ethanol/acetonitrile
(1:1) solvent system. Yield: 78 mg (75%). M.p. 348Ϫ350 °C (de-
Figure 4. Molecular structure of the dication 9; thermal ellipsoids
are drawn at the 50% probability level; hydrogen atoms are omitted
for clarity
Eur. J. Inorg. Chem. 2004, 4402Ϫ4411
www.eurjic.org
 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
4407

J. Hausmann, S. Käss, S. Klod, E. Kleinpeter, B. Kersting
comp.). UV/Vis (CH3CN): λmax (ε) ϭ 385 (2400), 651 (26), 1116 nm (15), 1124 nm (17 Ϫ1cmϪ1). IR (KBr): ν˜ 1202vs cmϪ1
FULL PAPER
ϭ
(65 Ϫ1cmϪ1). IR (KBr): ν˜ ϭ 1598 cmϪ1, 1566 s [νas(RCO2Ϫ)], [ν(RSO3Ϫ)], 1092s [ν(ClO4Ϫ)]. C38H64Cl2N6Ni2O10S2·2H2O·EtOH
1423 s [νs(RCO2Ϫ)], 1098 vs [ν(ClO4Ϫ)]. The tetraphenylborate salt
[(L1)NiII2(m-ClϪOBz)]BPh4 (2·BPh4) was prepared by adding
NaBPh4 (342 mg, 1.00 mmol) to a solution of 2·ClO4 (104 mg,
(1017.4 ϩ 82.1): calcd. C 43.70, H 6.78, N 7.64, S 5.83; found C
43.35, 6.98, 7.88, 5.47. The tetraphenylborate salt
[(L2)Ni2(Cl)]BPh4 (4·BPh4) was prepared by adding NaBPh4
H
N
S
0.100 mmol) in methanol (40 mL). The resulting green solid was (342 mg, 1.00 mmol) to a solution of 4·ClO4 (105 mg, 0.100 mmol)
recrystallized from a mixed ethanol/acetonitrile solution. Yield: in methanol (40 mL). The resulting green solid was recrystallized
101 mg (80%). M.p. 298Ϫ300 °C (decomp.). UV/Vis (CH3CN): from a mixed ethanol/acetonitrile solution. Yield: 111 mg (90%).
λmax (ε) ϭ 385 (2500), 649 (34), 1115 nm (68 Ϫ1cmϪ1). IR (KBr):
M.p. 330Ϫ334°C (decomp.). IR (KBr): ν˜ ϭ 1203 vs cmϪ1
ν˜ ϭ 1601 s cmϪ1, 1580 w, 1564 s [νas(RCO2Ϫ)], 1423 [νs(RCO2Ϫ)], [ν(RSO3Ϫ)]. C62H84BClN6Ni2O6S2·EtOH (1237.2 ϩ 46.1): calcd. C
732, 703 (BPh4Ϫ). C69H88BClN6Ni2O2S2 (1261.3): calcd. C 65.71, 59.90, H 7.07, N 6.55, S 5.00; found C 60.27, H 6.86, N 6.61, S
H 7.03, N 6.66, S 5.08; found C 65.26, H 7.23, N 6.55, S 5.04. The
tetraphenylborate salt 2·BPh4 was additionally characterized by X-
ray crystallography.
4.96. The tetraphenylborate salt was additionally characterized by
X-ray crystallography. The oxidation of 1·ClO4 by meta-chloro-
peroxybenzoic acid yields 3·ClO4 (vide supra).
[(L2)Ni2(m-Cl-OBz)]ClO4 (3·ClO4). Method A (Oxidation with [(L2)Ni2(OAc)]ClO4 (6·ClO4). Method A (Oxidation with meta-
meta-Chloroperoxybenzoic acid, MCPBA): A solution of meta-
chloroperoxybenzoic acid (121 mg, 0.700 mmol) in acetonitrile
Chloroperoxybenzoic Acid): A solution of the acetato-bridged com-
plex 5·ClO4 (94 mg, 0.10 mmol) in acetonitrile (30 mL) was added
(2 mL) was added dropwise to a solution of the perchlorate salt slowly to a solution of meta-chloroperoxybenzoic acid (0.12 g,
2·ClO4 (104 mg, 0.100 mmol) in acetonitrile (30 mL). During the
addition the temperature was kept at 0 °C. After stirring for 2 h, a
solution of LiClO4·3H2O (500 mg, 3.12 mmol) in ethanol (40 mL)
was added. The product precipitated during evaporation of the sol-
vent (the final amount of solvent was 3Ϫ4 mL). The pale-
green microcrystalline material was isolated by filtration and
dried in air. Yield: 95 mg (84%). M.p. 348Ϫ350°C (decomp.).
0.70 mmol) in acetonitrile (2 mL). During the addition the tem-
perature was kept at 0 °C. After stirring for 30 min, a solution of
LiClO4·3H2O (0.500 g, 3.12 mmol) in ethanol (40 mL) was added.
The product precipitated during evaporation of the solvent (the
final amount of solvent was 3Ϫ4 mL). The pale-green microcrystal-
line material was isolated by filtration and dried in air. Yield: 87 mg
(84%). M.p. 344Ϫ348°C (decomp.). UV/Vis (CH3CN): λmax (ε) ϭ
UV/Vis (CH3CN): λmax (ε) ϭ 400 (47), 674 (16), 1126 nm 398 (55), 670 (25), 1122 nm (47 Ϫ1cmϪ1). IR (KBr): ν˜ ϭ1611 sh
(15 Ϫ1cmϪ1). IR (KBr): ν˜ ϭ 1606 cmϪ1, 1563 s [νas(RCO2Ϫ)], cmϪ1 [νas(RCO2Ϫ)], 1411 [νs(RCO2Ϫ)], 1202 vs
1597
1410 s [νs(RCO2Ϫ)], 1220 vs [ν(RSO3Ϫ)], 1091 vs [ν(ClO4Ϫ)]. [ν(RSO3Ϫ)], 1092 s [ν(ClO4Ϫ)]. C40H67ClN6Ni2O12S2·4H2O (1041.0
,
s
w
C45H68Cl2N6Ni2O12S2·2H2O·EtOH (1137.5
ϩ
82.1): calcd.
C
ϩ 72.1): calcd. C 43.16, H 6.79, N 7.55, S 5.76; found C 43.73, H
6.94, N 7.43, S 5.34.
45.61, H 6.52, N 6.79, S 5.18; found C 46.00, H 6.82, N 6.89, S
4.77. The tetraphenylborate salt [(L2)Ni2(m-ClϪOBz)]BPh4
(3·BPh4) was prepared by adding NaBPh4 (342 mg, 1.00 mmol) to
a solution of 3·ClO4 (114 mg, 0.100 mmol) in methanol (40 mL).
The resulting pale-green solid was recrystallized from a mixed etha-
nol/acetonitrile solution. Yield: 128 mg (94%). M.p. 340Ϫ344°C
Method B (Oxidation by Hydrogen Peroxide): Hydrogen peroxide
(1.00 mL, 35 wt.-% solution in water, 11.7 mmol) was added to a
solution of 5·ClO4 (94 mg, 0.10 mmol) in methanol (30 mL). The
reaction mixture was refluxed for 5 h to give a pale-green solution.
After cooling to room temperature, a solution of LiClO4·3H2O
(decomp.). IR (KBr): ν˜ ϭ 1608 cmϪ1, 1565 s [νas(RCO2Ϫ)], 1410 w (0.500 g, 3.12 mmol) in ethanol (40 mL) was added. The product
[νs(RCO2Ϫ)], 1218 vs [ν(RSO3Ϫ)], 732, 705
s
[ν(BPh4Ϫ)]. precipitated during evaporation of the solvent (the final amount of
C69H88BClN6Ni2O8S2·2H2O (1357.3 ϩ 36.0): calcd. C 59.48, H
6.66, N 6.03, S 4.60; found C 59.47, H 6.92, N 5.82, S 3.97.
Method B (Oxidation with Hydrogen Peroxide): Hydrogen peroxide
(1.00 mL, 35 wt.-% solution in water, 11.7 mmol) was added to a
solution of 2·ClO4 (104 mg, 0.10 mmol) in methanol (30 mL). The
reaction mixture was refluxed for 5 h to give a pale-green solution.
solvent was 3Ϫ4 mL). The pale-green microcrystalline material was
isolated by filtration and dried in air. Yield: 56 mg (50%). The ana-
lytical data of this material are identical to those of compound
6·ClO4 prepared by method A.
Method C (from the Free Ligand H2L2·6HCl): The reaction of
Ni(OAc)2·4H2O with H2L2·6HCl in the presence of a base also
After cooling to room temperature, a solution of LiClO4·3H2O gives 6·ClO4. The procedure is detailed below for the corresponding
(0.500 g, 3.12 mmol) in ethanol (40 mL) was added. The product
precipitated during evaporation of the solvent (the final amount of
solvent was 3Ϫ4 mL). The pale-green microcrystalline material was
isolated by filtration and dried in air. Yield: 70 mg (60%). The ana-
lytical data of this material are identical to those of compound
3·ClO4 prepared by method A. The tetraphenylborate salt was ad-
ditionally characterized by X-ray crystallography.
zinc complex 8.
H2L2·6HCl: Hydrochloric acid (12 , 100 mL) was added to a sus-
pension of complex 3·ClO4 (3.50 g, 3.08 mmol) in methanol
(300 mL) and the reaction mixture was stirred vigorously at 50 °C
for 24 h. The resulting solution was then concentrated at reduced
pressure (final volume ca 40 mL) and the pH adjusted to 13 with
5  aqueous potassium hydroxide solution. The resulting green sus-
pension was allowed to cool to room temperature, and the aqueous
[(L2)Ni2(Cl)]ClO4 (4·ClO4): H2O2 (1.00 mL, 35 wt.-% solution in
water, 11.7 mmol) was added to a solution of 1·ClO4 (92 mg, phase was extracted with dichloromethane (5 ϫ 100 mL). The or-
0.10 mmol) in methanol (30 mL). The reaction mixture was re-
fluxed for 4 h to give a pale-green solution. After cooling to room
temperature, a solution of LiClO4·3H2O (0.250 g, 1.56 mmol) in
ethanol (40 mL) was added. The product precipitated during evap-
oration of the solvent (the final amount of solvent was 3Ϫ4 mL).
The pale-green microcrystalline material was isolated by filtration
and dried in air. Yield: 63 mg (62%). An analytical sample was
obtained by recrystallization from acetonitrile/ethanol. M.p.
ganic fractions were combined and the dichloromethane was dis-
tilled off at reduced pressure to give a colorless solid. The residue
was redissolved in ethanol (100 mL), acidified to pH 1 with conc.
hydrochloric acid (ca. 3Ϫ4 mL), and the resulting solution quickly
filtered off from an insoluble white solid (KCl). Evaporation of
the solvent gave H2L2·6HCl as a colorless voluminous solid. M.p.
240Ϫ242°C (dec.). Yield: 2.63 g (85%). This material was pure en-
ough for metal-complex synthesis. IR (KBr): ν˜ ϭ 3023 w cmϪ1
,
318Ϫ320°C (decomp.). UV/Vis (CH3CN): λmax (ε) ϭ 396 (33), 686 2962 m, 2591 br. s, 1634, 1602, 1464 s, 1228 vs [ν(RSO3 H)], 1074
4408  2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim www.eurjic.org
Eur. J. Inorg. Chem. 2004, 4402Ϫ4411

Binucleating Aza-Sulfonate and Aza-Sulfinate Macrocycles
FULL PAPER
s, 1019 s, 688 s, 662 s. C38H72Cl6N6O6S2 (H2O)3 (985.86 ϩ 54.05): dried in air. Yield: 45 mg (45%). M.p. 350Ϫ352°C (decomp.). IR
calcd. C 43.89, H 7.65, N 8.08, S 6.17; found C 44.02, H 7.37, N
(KBr): ν˜ ϭ 1058 cmϪ1, 970 [ν(RSO2Ϫ)], 1090 s [ν(ClO4Ϫ)]. UV/
Vis (CH3CN): λmax (ε) ϭ 668 (430), 947 sh nm (153 Ϫ1cmϪ1).
1
7.75, S 5.91. H NMR (200 MHz, D2O, 330 K): δ ϭ 7.87 (s, 4 H,
3
ArH), 4.86 (s, 8 H, ArCH2), 3.72 (t, J, 5.6 Hz, 8 H, CH2), 3.33 (t, C38H64Cl2Cu2N6O8S2 (995.08): calcd. C 45.87, H 6.48, N 8.45, S
3J, 5.6 Hz, 8 H, CH2), 3.02 (s, 12 H, BzNCH3), 2.45 (s, 6 H.
NCH3), 1.47 [s, 18 H, C(CH3)3] ppm. 13C{1H} NMR (50 MHz,
D2O): δ ϭ 30.9 [C(CH3)3], 35.4 [C(CH3)3] 41.5 (CH3), 52.5 (CH2),
52.9 (CH2), 60.9 (CH2), 128.6, 136.0 (CH), 142.2, 157.4 ppm; one
aliphatic carbon signal was not observed.
6.44; found C 45.66, H 6.53, N 8.33, S 6.22. This compound was
additionally characterized by X-ray crystallography.
Crystal Structure Determinations: Single crystals of 2·BPh4·
1.25CH3CN, 3·BPh4·4EtOH·2H2O, and 4·BPh4·2EtOH·0.5CH3CN
suitable for X-ray structure analysis were grown from an aceto-
nitrile/ethanol (1:1) mixed-solvent system. Crystals of
9·(ClO4)2·H2O were grown from methanolic solution. The crystals
were mounted on glass fibers in perfluoropolyether oil. Intensity
data were collected at 210(2) K, using a Bruker SMART CCD
diffractometer. Graphite-monochromated Mo-Kα radiation (λ ϭ
[(L2)Zn2(OAc)](ClO4) (8·ClO4): Zn(O2CCH3)2·2H2O (44 mg,
0.20 mmol) and triethylamine (61 mg, 0.60 mmol) were added to a
solution of H2L2·6HCl (99 mg, 0.10 mmol) in methanol (25 mL).
After stirring the reaction mixture for 2 d at room temperature,
solid LiClO4·3H2O (321 mg, 2.00 mmol) was added. The mixture
was then stirred for a further 12 h. The resulting white precipitate
was collected by filtration and recrystallized from an acetonitrile/
ethanol mixed-solvent system. Yield: 96 mg (91%). M.p.
360Ϫ364°C (decomp.). IR (KBr): ν˜ ϭ 1595s cmϪ1 [νas(RCO2Ϫ)],
1411 w [νs(RCO2Ϫ)], 1202 vs [ν(RSO3Ϫ)], 1090 s [ν(ClO4Ϫ)]. 1H
˚
0.71073 A) was used throughout. The data were processed with
SAINT and corrected for absorption using SADABS[47] (trans-
mission factors: 1.00Ϫ0.89 for 2, 1.00Ϫ0.58 for 3, 1.00Ϫ0.85 for 4,
and 1.00Ϫ0.91 for 9). The structures were solved by direct methods
using the program SHELXS-86[48] and refined by full-matrix least-
squares techniques against F2 using SHELXL-97.[49] The ShelXTL
version 5.10 program package was used for the structure solutions
and refinements.[50] PLATON was used to search for higher sym-
metry.[51] Ortep3 was used for the artwork of the structures.[52] Un-
less otherwise noted all non-hydrogen atoms were refined aniso-
tropically. Hydrogen atoms were assigned to idealized positions and
given isotropic thermal parameters 1.2-times (1.5-times for CH3
groups) the thermal parameter of the atoms to which they are at-
2
NMR (200 MHz, CD3OD): δ ϭ 7.26 (s, 4 H, ArH), 4.58 (d, J ϭ
12.4 Hz, 4 H, ArCH2), 3.00 (d, 2J ϭ 12.4 Hz, 4 H, ArCH2),
2.95Ϫ2.75 (m, 16 H, CH2), 2.68 (s, 6 H, NCH3), 2.47 (s, 12 H,
NCH3), 1.26 [s, 18 H, C(CH3)3], 0.59 (s, 3 H, CH3) ppm. 13C{1H}
NMR (50 MHz, CDCl3): δ ϭ 173.1, 153.2, 143.5, 133.3, 132.5,
64.4, 57.1, 52.8, 45.3, 44.7, 35.08, 30.9, 23.3 ppm.
C40H67ClN6O12S2Zn2·4H2O (1054.4 ϩ 72.1): calcd. C 42.65, H
6.71, N 7.46, S 5.69; found C 42.58, H 6.74, N 7.36, S 5.20.
[(L3)Cu2](ClO4)2 (9·2ClO4): [Cu(CH3CN)4]ClO4 (65 mg, 0.20 tached. Selected details of the data collection and refinement are
mmol) and triethylamine (81 mg, 0.80 mmol) were added success-
ively to a suspension of H2L1·6HCl (89 mg, 0.10 mmol) in meth-
anol (40 mL). The colorless reaction mixture was stirred for 24 h
and was then exposed to air to give a dark-green solution. A solu-
tion of LiClO4·3H2O (160 mg, 1.00 mmol) in methanol was added.
given in Table 4.
In the crystal structure of 2 two tert-butyl groups were found to be
disordered over two positions. A split-atom model was applied for
the disordered tBu groups. The site occupancies of the two orien-
tations were refined as 0.70(1)/0.30(1) [for C(32a/c), C(33a/c),
The mixture was then filtered and stored in an open vessel for five C(34a/c)] and 0.62(1)/0.38(1) [for C(36a/c), C(37a/c), C(38a/c)]. All
days. The resulting green crystals were isolated by filtration and non-hydrogen atoms were refined anisotropically, except the nitro-
Table 4. Crystallographic data for 2·BPh4·1.25MeCN, 3·BPh4·4EtOH·2H2O, 4·BPh4·EtOH·0.5CH3CN, and 9·(ClO4)2·H2O
Compound
2·BPh4·1.25MeCN
3·BPh4·4EtOH·2H2O
4·BPh4·EtOH·0.5CH3CN 9·(ClO4)2·H2O
Formula
C71.5H91.75BClN7.25Ni2O8S2 C77H116BClN6Ni2O14S2 C65H91.5BClN6.5Ni2O7S2
C38H68Cl2Cu2N6O14S2
1095.08
P21/c
12.688(3)
9.131(2)
20.780(4)
90.00
106.25(3)
90.00
2311.3(9)
2
Mr (g/mol)
Space group
1312.57
P1
1577.56
C2/c
1303.75
P21/c
¯
˚
a (A)
13.003(3)
15.939(3)
33.871(7)
77.22(3)
82.06(3)
82.75(3)
6747(2)
31.604(6)
16.444(4)
34.628(6)
90.00
111.02(2)
90.00
19.960(4)
19.772(4)
33.322(7)
90.00
93.514(5)
90.00
˚
b (A)
˚
c (A)
α (°)
β (°)
γ (°)
3
˚
V (A )
16798(6)
8
13126(5)
8
Z
4
dcalcd. (g/cm3)
Cryst. size (mm3)
µ(Mo-Kα) (mmϪ1
2θ limits (deg)
Measured refl.
Independent refl.
Observed refl.[a]
No. parameters
1.292
0.30 ϫ 0.30 ϫ 0.30
0.710
2.64Ϫ58.14
61676
31611
12737
1608
0.0533 (0.1054)
0.1639 (0.1410)
1.248
0.20 ϫ 0.26 ϫ 0.31
0.591
1.52Ϫ57.66
42079
18414
5500
802
0.0783 (0.1996)
0.2458 (0.2737)
1.309, Ϫ1.219
1.319
0.30 ϫ 0.30 ϫ 0.20
0.734
3.10Ϫ57.76
81701
31159
12272
1519
0.0554 (0.1378)
0.1696 (0.1784)
1.237, Ϫ1.160
1.574
0.20 ϫ 0.20 ϫ 0.20
1.197
3.34Ϫ56.60
14432
5571
3025
289
0.0446 (0.0969
0.1032 (0.1153)
0.591, Ϫ0.565
)
R1[b] (R1 all data)
wR2[c] (wR2 all data)
Max., min. peaks (e/A ) 0.724, Ϫ0.831
3
˚
[a]
[b]
[c]
2
2 2
2 2
Observation criterion: I Ͼ 2σ(I). R1 ϭ Σ||Fo| Ϫ |Fc||/Σ|Fo|. wR2 ϭ {Σ[w(Fo Ϫ Fc ) ]/Σ[w(Fo ) ]}1/2
.
Eur. J. Inorg. Chem. 2004, 4402Ϫ4411
www.eurjic.org
 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
4409

J. Hausmann, S. Käss, S. Klod, E. Kleinpeter, B. Kersting
FULL PAPER
gen and carbon atoms [N(9), C(51), C(52)] of one half-occupied Supporting Information Available: Figures S1 and S2 (see also the
acetonitrile solvent molecule. No hydrogen atoms were calculated footnote on the first page of this article). The calculated chemical
for the methyl carbon atom C(52). In the crystal structure of 3, the
C and O atoms of the ethanol and water molecules of solvent of
crystallization were found to exhibit very large thermal parameters
indicative of severe disorder. This disorder could not be modeled by
using split-atom models, therefore the coordinates of the respective
atoms were fixed at their initial positions and given a common
isotropic thermal parameter of 0.20. No problems were encoun-
tered with the refinement of the [(L2)Ni2(m-Cl-OBz)]ϩ cation. The
relatively large R value is due to the disorder of the solvent mol-
ecules. In the crystal structure of 4, one tert-butyl group and the
two ethanol molecules of crystallization were found to be dis-
ordered over two positions. A split atom model was applied to ac-
count for this disorder. The site occupancies of the two orientations
were refined as 0.53(1)/0.47(1) [for C(32a/b), C(33a/b), C(34a/b)],
0.71(1)/0.29(1) [for O(5a/b), C(39a/b), C(40a/b)], and 0.78(1)/
0.22(1) [for O(7a/b), C(41a/b), C(42a/b)]. The disorder of the aceto-
nitrile molecule of solvent of crystallization could not be modeled
by using a split-atom model, therefore the coordinates of the C and
N atoms were fixed at their initial positions and given a common
isotropic thermal parameter of 0.20. No hydrogen atoms were cal-
culated for the solvate molecules. In the crystal structure of
9·(ClO4)2(H2O) no hydrogen atoms were calculated for the H2O
molecule.
shielding values at the positions of the three methyl protons of the
bridging acetate ions in 7 and 8.
Acknowledgments
We are particularly grateful to Prof. Dr. H. Vahrenkamp for provid-
ing facilities for NMR and X-ray crystallographic measurements.
Financial support of this work from the Deutsche Forschungsge-
meinschaft (Priority programme ‘‘Sekundäre Wechselwirkungen’’,
KE 585/3-1,2) and by the Wissenschaftliche Gesellschaft in Frei-
burg is gratefully acknowledged.
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Eur. J. Inorg. Chem. 2004, 4402Ϫ4411

Binucleating Aza-Sulfonate and Aza-Sulfinate Macrocycles
FULL PAPER
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[30]
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[32]
Abbreviations: MCPBA ϭ meta-chloroperoxybenzoic acid (m-
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ϭ
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Received June 2, 2004
Early View Article
Published Online October 7, 2004
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4411