Self-assembly of diphenyltin(iv) and tris-dithiocarbamate ligands to racemic trinuclear cavitands and capsules

Article abstract of DOI:10.1039/b811768n

Racemic trinuclear diphenyltin(iv) cavitands and capsules have been assembled from diphenyltin(iv) and tris-dithiocarbamate ligands.

Full text of DOI:10.1039/b811768n

View Article Online / Journal Homepage / Table of Contents for this issue
PAPER
www.rsc.org/dalton | Dalton Transactions
Self-assembly of diphenyltin(IV) and tris-dithiocarbamate ligands to racemic
trinuclear cavitands and capsules†
Reyna Reyes-Mart´ınez, Patricia Garc´ıa y Garc´ıa, Marcela Lo´pez-Cardoso,* Herbert Ho¨pfl and Hugo Tlahuext*
Received 16th June 2008, Accepted 29th July 2008
First published as an Advance Article on the web 10th October 2008
DOI: 10.1039/b811768n
Racemic trinuclear diphenyltin(IV) cavitands and capsules have been assembled from diphenyltin(IV)
and tris-dithiocarbamate ligands.
1
Introduction
Currently, it is one of the major objectives of supramolecular
chemistry to establish synthetic strategies that allow for the
generation of assemblies capable to encapsulate guest molecules in
a selective manner.1 Dithiocarbamate (dtc) ligands can be useful
tectons for this purpose, since complex supramolecular architec-
tures such as macrocycles, cages, catenanes and nanodimensional
assemblies can be generated from a variety of oligofunctional
constructs in combination with metal ions.2 Moreover, it has been
shown that macrocycles derived from di- and tripodal-dtc ligands
have the potential to bind, sense and react together with guest
substrates. Additionally, they can have unique redox, magnetic
and photochemical properties, thus making them interesting
objects of study.3 Previously, the synthesis of neutral trinuclear
metallocryptands has been achieved via the combination of tris-
(pyrrole-functionalized)-dtc frameworks with metal centers hav-
ing a square-planar coordination preference [zinc(II), nickel(II) or
copper(II) salts].4a When bis-dithiocarbamate salts were combined
with octahedral centers such as Fe(III) and Co(III), bimetallic
capsules were obtained.4b
So far, little is known about supramolecular assemblies derived
from organometallic building blocks. In reality, there are only few
useful candidates and among these organotin systems have shown
to be particularly interesting.5 However, so far the vast majority
of metallosupramolecular tin assemblies have been constructed
from ligands having nitrogen or oxygen as metal-coordinating
donors, and systems with other donor atoms such as sulfur and
phosphorus are almost unexplored.6
Scheme 1
2
Results and discussion
2.1 Syntheses and spectroscopy characterization
The tripodal tris-dithiocarbamate ligands required for the prepa-
ration of compounds 1–5 were obtained from the combination of
three different trisamines: tris[2-(methylamino)ethyl]amine, tris[2-
(isopropylamino)ethyl]amine and tris[2-(benzylamino)ethyl]-
amine, with carbon disulfide and potassium hydroxide as base.
Subsequent reaction with diphenyltin dichloride, Ph2SnCl2, in 1 : 3
and 2 : 3 ligand-to-diphenyltin(IV) ratios formed the trinuclear
vase-shaped cavitands 1–3 and capsules 4–5 in yields ranging from
45 to 69%. The inherently chiral cavitands 1–3 and capsules 4–5
are formed as racemates because nonchiral ligands and solvents
were used.9
The composition of the resulting products was established as
far as possible by elemental analysis, mass spectrometry, IR and
NMR (1H, 13C, 119Sn) spectroscopy, and X-ray crystallography (1,
4 and 5). The formation of the dtc functions could be evidenced
straightforward from the IR, 13C and 119Sn NMR spectra. The IR
spectra showed bands in the range from 1451 to 1518 cm-1 and
954 to 996 cm-1 that are typical for the vibrations of the C–Ndtc
bonds and CS2 groups, respectively.10 The 13C NMR signals of the
dtc carbon atoms (N13CSS) are found in the range of dC 196.32
to 198.72 ppm for compounds 1–3, and dC 200.31 to 202.13 ppm
for compounds 4–5, and agree well with previously reported data
on metal dtc complexes.6 The 119Sn NMR chemical shift values
for compounds 1–3 and 4–5 were found in the ranges of -311 to
-319 ppm and d = -512 to -514 ppm, respectively, indicating that
Recently, we reported the synthesis of two new dinuclear tin
macrocycles based on dtc ligands.7 In this contribution we present
now the synthesis of a series of chiral trinuclear diphenyltin(IV)
cavitands, 1–3, and capsules, 4–5, which were derived from
tris[2-(N-alkyldithiocarbamate)ethyl]amine ligands (Scheme 1).
The synthesis of chiral molecular capsules via coordination-
bonds is important, because they should show more interesting
recognition properties from the viewpoints of potential applica-
tions.8
Centro de Investigaciones Qu´ımicas, Universidad Auto´noma del Estado de
Morelos, Av., Universidad 1001, Col.. Chamilpa, C.P. 62209, Cuernavaca,
Morelos, Me´xico. E-mail: marce@ciq.uaem.mx, tlahuext@ciq.uaem.mx
† CCDC reference numbers 666754, 691815 and 691697. For crystallo-
graphic data in CIF or other electronic format see DOI: 10.1039/b811768n
6624 | Dalton Trans., 2008, 6624–6627
This journal is
The Royal Society of Chemistry 2008
©

View Article Online
in solution the tin atoms are penta-coordinated in the first case,
and hexa-coordinated in the second case.6
structure shows that both the N-methyl and Ph2(Cl)Sn groups
oriented to the outer-sphere of the cavitand are arranged in form
of a propeller, thus giving a chiral assembly. However, within the
crystal lattice, both enantiomers are present (space group P-1),
whereas in solution the chirality is vanished due to the unhindered
rotational movement of the tripodal arms (vide supra).
The 2:3 reaction products 4 and 5 gave spherical capsules
(Fig. 2–3) that crystallized in the D3d and C3i crystallographic point
groups, respectively, indicating that they are racemic compounds,
too. In capsules 4 and 5 the tin and amine nitrogen atoms
are forming a trigonal-bipyramidal polyhedron with average
Interestingly, in the 1H NMR spectra of compounds 4 and 5 the
aliphatic protons of the i-propyl and benzyl groups gave signals for
diastereotopic hydrogen atoms, indicating that the tin atoms are
stereogenic centers. For compound 4 two doublets were observed
for the methyl groups at dH 1.15 and 1.26 ppm, while the hydrogen
atoms in the methylene group of compound 5 gave an AB system
(dH 4.75 and 5.34 ppm with Jgem 15.2 Hz). In comparison, for the
1
analogous semi-capsules 2 and 3 the H NMR spectra gave only
one doublet for the methyl groups (dH 1.27 ppm, 3J 6.8 Hz) and a
single signal for the methylene group (dH 4.83 ppm), respectively.
The mass spectra (FAB+) of compounds 1–5 support the
assumption that trinuclear diorganotin(IV) dithiocarbamate cavi-
tands and capsules had been obtained. In all cases the molecular
ions could not be detected, but it was possible to detect peaks
corresponding to the [M - Cl]+ (compounds 1–3) and [M - C6H5]+
(compounds 4–5) fragments: m/z 1303 for 1, 1387 for 2, 1531 for
3, 1737 for 4 and 2025 for 5.
˚
Sn ◊ ◊ ◊ Sn, Sn ◊ ◊ ◊ N and N ◊ ◊ ◊ N distances of 10.73, 6.79 and 5.19 A,
respectively.
2.2 X-Ray crystal structures
Single crystals of 1, 4 and 5 were grown at room temperature by
slow evaporation of chloroform–ethanol (1 : 1, 1), bromoform–
methanol (1 : 2, 4) and chloroform–benzene (3 : 2, 5) solutions.‡
The molecular structure of complex 1 is given in Fig. 1 (top
view), showing that this compound possesses a trinuclear vase-
shaped cavitand structure. A careful inspection of the molecular
Fig. 2 Perspective view of the molecular structure of compound 4,‡
showing 50% probability displacement ellipsoids. For clarity, hydrogen
atoms and solvent molecules are omitted.
Fig. 1 Perspective view of the molecular structure of compound 1,‡
showing 50% probability displacement ellipsoids. For clarity, hydrogen
atoms are omitted.
‡ Crystal data for 1, 4 and 5: C48H51Cl3N4S6Sn3 1, M = 1338.71, triclinic,
˚
space grou◦p P-1, a = 10.0012(6), b = 17.2313(10), c = 18.2621(10) A, a =
◦
◦
3
˚
115.029(1) , b = 103.792(1) , g = 90.019 (1) , V = 2751.0 (3) A , T =
293 K, Z = 2. 26606 reflections measured, 9651 unique (Rint = 0.0580) and
7263 with I > 2 s(I). The final R values were R1 = 0.0931 and wR2 (all
data) = 0.1827. CCDC 666754. C72H96N8S12Sn3·2CHBr3 4, M = 2319.85,
3
˚
˚
trigonal, space group R-3c, a = 16.423(5), c = 59.95(3) A, V = 14005 (9) A ,
T = 293 K, Z = 6. 21255 reflections measured, 2757 unique (Rint = 0.0460),
2278 with I > 2 s(I). The final R values were R1 = 0.0431 and wR2 (all
data) = 0.1122. CCDC 691815. C96H96N8S12Sn3· 2(CHCl3)·3(C6H6) 5, M =
˚
2575.66, trigonal, space group P-3, a = 22.2740(12), c = 13.8830(11) A,
3
Fig. 3 Perspective view of the molecular structure of compound 5,‡
showing 50% probability displacement ellipsoids. For clarity, hydrogen
atoms and solvent molecules are omitted.
˚
V = 5965.0 (7) A , T = 100 K, Z = 2. 43833 reflections measured, 7027
unique (Rint = 0.0698), 5787 with(I > 2 s(I). The final R values were R1 =
0.0531 and wR2 (all data) = 0.1316. CCDC 691697.
This journal is
The Royal Society of Chemistry 2008
Dalton Trans., 2008, 6624–6627 | 6625
©

View Article Online
In all cases, the dtc moieties are coordinated to the tin atoms
in the anisobidentate manner. The covalent Sn–S bonds are in
(0.100 g, 0.37 mmol) and potassium hydroxide (0.061 g,
1.10 mmol) in methanol (5 ml) carbon disulfide (0.2 ml, 3.3 mmol)
was added, and the solution was stirred at 20 ◦C for 1 hour. A
solution of Ph2SnCl2 (0.378 g, 1.10 mmol) in methanol (5 ml)
was added. The white precipitate was collected by filtration (yield
0.25 g, 48%). Mp 164–165 ◦C (from MeOH). Elemental analysis
(Found: C, 44.8; H, 4.5; N, 4.6; Calc. for C54H63Cl3N4S6Sn3, C,
45.6; H, 4.5; N, 3.9). IR (KBr) nmax/cm-1 967 (CS2), 1480 (N-CS2).
dH (400 MHz; CDCl3; Me4Si) 1.27 (18H, d, 3J = 6.8, CH3), 3.01
˚
the range [2.437(3)–2.5813(13) A], and the secondary interactions
˚
are in the range [2.667(2)–2.7081(13) A]. While the tin atoms in 1
are penta-coordinated, showing a distorted trigonal-bipyramidal
polyhedron, in which the equatorial angles vary from 111.9(3)
to 124.7(3)◦ and the axial angles from 153.35(10) to 157.33(9)◦,
the tin atoms in compounds 4 and 5 are hexa-coordinated with
distorted octahedral polyhedron geometries (twist distortion).
3
3
(6H, t, J = 7.6, N(1)CH2), 3.66 (6H, t, J = 7.6, CH2NCS2),
4.89 (3H, h, 3J = 6.8, NCH), 7.41–7.49 (18H, m, CHm,p of
SnPh2), 8.00–8.04 (12H, m, CHo of SnPh2); 3J(119Sn, 1H) 85.9. dC
(200 MHz; CDCl3; Me4Si) 20.58 (CH3), 52.35 (N(1)CH2), 48.60
(CH2NCS2), 58.70 (NCH), 129.00 (Cm), 130.43 (Cp), 135.79 (Co),
141.86 (Ci), 196.32 (CS2); 2J(119Sn,13C) 64.0, 3J(119Sn, 13C) 86.9. dSn
(400 MHz; CDCl3; Me4Sn) 311. m/z (FAB+) 1387 (M+ - Cl, 21%).
3
Conclusions
In conclusion, this contribution has shown that the self-assembly
process of dtc ligands with diorganotin centers allows to construct
racemic cavitands and capsules, in which in the latter case the
tin atoms are the stereogenic centers. This makes these capsules
interesting candidates for the molecular recognition of chiral Lewis
basic substrates.
Tris[2-(N-benzyldithiocarbamate)ethyl]aminodiphenyltin
(IV)
chloride 3. To a solution of tris[2-(benzyl)ethyl]amine (0.100 g,
0.24 mmol) and potassium hydroxide (0.040 g, 0.72 mmol) in
methanol (5 ml) carbon disulfide (0.2 ml, 3.3 mmol) was added,
and the solution was stirred at 20 ◦C for 1 hour. A solution of
Ph2SnCl2 (0.248 g, 0.72 mmol) in methanol (5 ml) was added.
The white precipitate was collected by filtration (yield 0.26 g,
69%). Mp 182–186 ◦C (from MeOH). Elemental composition by
HR-FAB-MS, observed m/z 1532.0037 (M+ - Cl, 100%) error
+19.2 ppm. IR (KBr) nmax/cm-1 996 (CS2), 1497 (N-CS2). dH
4
Experimental
4.1 General details
Instrumental: NMR studies were carried out with Varian Gemini
200 and Varian Inova 400 instruments. Chemical shifts (dH, dC and
dSn) and J values are given in ppm and Hz, respectively. Standard
references were used: TMS (dH = 0 and dC = 0) and SnMe4 (d
119Sn = 0). The dH and dC values for the racemic capsules 4–5 were
assigned by 2D NMR experiments. IR spectra have been recorded
on a Bruker Vector 22 FT spectrophotometer. Mass spectra were
obtained on a Jeol JMS 700 equipment. Elemental analyses have
been carried out on an Elementar Vario ELIII instrument, using
samples that have been dried previously at 65 ◦C for 2 h in an
Abderhalden equipment.
3
(400 MHz; CDCl3; Me4Si) 2.50 (6H, t, J= 7.4, N(1)CH2), 3.49
3
(6H, t, J= 7.4, CH2NCS2), 4.83 (6H, s, NCH2Ph), 7.17–7.28
(15H, m, CH2Ph), 7.43–7.49 (18H, m, CHm,p of SnPh2), 8.03–8.06
(12H, m, CHo of SnPh2); 3J(119Sn, 1H) 87.0. dC (400 MHz; CDCl3;
Me4Si), 50.57 (N(1)CH2), 53.41 (CH2NCS2), 60.94 (CH2Ph),
[129.09 (Cm), 130.55 (Cp), 135.81 (Co), 141.77 (Ci); SnPh2]; [128.10
(Cm), 128.45 (Cp), 129.39 (Co), 133.27 (Ci), CH2Ph], 198.72 (CS2);
2J(119Sn,13C) 64.0, 3J(119Sn, 13C) 80.8. dSn (400 MHz; CDCl3;
Me4Sn) 315. m/z (FAB+) 1531 (M+ - Cl, 11%).
4.2 Syntheses
Bis-{tris[2-(N-isopropyldithiocarbamate)ethyl]amino} diphenyl-
tin(IV) 4. To a solution of tris[2-(isopropylamino)ethyl]amine
(0.100 mL, 0.314 mmol) and potassium hydroxide (0.052 g,
0.944 mmol) in methanol (5 ml) carbon disulfide (0.2 mL, 3.3
mmol) was added and the solution was stirred at 20 ◦C for 1 hour.
A solution of Ph2SnCl2 (0.160 g, 0.467 mmol) in methanol (5 ml)
was added and the resulting precipitate was collected by filtration.
The solid was recrystallized in a mixture of CH2Cl2–MeOH (1 : 2)
(yield 0.128 g, 45.2%). Mp 243–245 ◦C (from CH2Cl2/MeOH).
Crystals suitable for X-ray crystallography were grown from a
solution of 4 in bromoform-methanol (1:2). Elemental analysis
(Found: C, 47.1; H, 5.4; N, 6.3; Calc. for C72H96N8S12Sn3: C,
47.7; H, 5.3; N, 6.2). IR (KBr) nmax/cm-1 970 (CS2), 1451 (N-
Tris[2-(N-methyldithiocarbamate)ethyl]amine
diphenyltin(IV)
chloride 1. To a solution of tris[2-(methylamino)ethyl]amine
(0.100 g, 0.53 mmol) and potassium hydroxide (0.089 g, 1.59
mmol) in methanol (5 ml) carbon disulfide was added (0.2 ml,
3.3 mmol), and the solution was stirred at 20 ◦C for 1 hour. A
solution of Ph2SnCl2 (0.547 g, 1.59 mmol) in methanol (5 ml)
was added. The white precipitate was collected by filtration (yield
0.49 g, 69%). Mp 183–185 ◦C (from MeOH). Crystals suitable
for X-ray crystallography were grown from a solution of 1 in
chloroform–ethanol (1 : 1). Elemental analysis (Found: C, 42.5;
H, 3.7; N, 4.0. Calc. for C48H51Cl3N4S6Sn3: C, 43.1; H, 3.8; N,
4.2). IR (KBr) nmax/cm-1 982 (CS2), 1518 (N-CS2). dH (200 MHz;
CDCl3; Me4Si) 2.83 (6H, t, 3J = 6.2, N(1)CH2), 3.21 (9H, s,
3
CS2). dH (400 MHz; CDCl3; Me4Si; COSY) 1.15 (18H, d, J =
3
NCH3), 3.67 (6H, t, J = 6.2, CH2NCS2), 7.38–7.50 (18H, m,
3
6.8, CHCH3A), 1.26 (18H, d, J = 6.4, CHCH3B), 2.91 (6H, m,
CHm,p of SnPh2), 8.03 (12H, d, J = 6.4, CHo of SnPh2), 3J(119Sn,
1H) 83.0. dC (200 MHz; CDCl3; Me4Si) 44.76 (NCH3), 50.85
(NCH2), 56.65 (CH2NCS2), 129.01 (Cm), 130.46 (Cp), 135.68
N(1)CHA), 3.22 (6H, m, CHBNCS2), 3.24 (6H, m, N(1)CHB), 3.85
(6H, m, CHANCS2), 4.91 (6H, m, NCH(CH3)2), 7.27–7.32 (18H,
m, CHo,p of SnPh2), 7.69–7.71 (12H, m, CHo of SnPh2); 3J(119Sn,
1H) 84. dC (400 MHz; CDCl3; Me4Si; HSQC), 20.56 (CH3A), 21.78
(CH3B), 48.33 (CH2NCS2), 53.03 (N(1)CH2), 57.78 (NCH(CH3)2),
[128.20 (Cm), 128.4 (Cp), 133.99 (Co), 153.51 (Ci), SnPh2], 200.31
(CS2). dSn (400 MHz; CDCl3; Me4Sn) 514. m/z (FAB+) 1737 (M+ -
C6H5, 20%).
2
3
(Co), 141.56 (Ci), 197.17 (CS2); J(119Sn, 13C) 61.0, J(119Sn, 13C)
85.4. dSn (400 MHz; CDCl3; Me4Sn) 319. m/z (FAB+) 1303 (M+ -
Cl, 12%).
Tris[2-(N-isopropyldithiocarbamate)ethyl]amine diphenyltin(IV)
chloride 2. To a solution of tris[2-(isopropylamino)ethyl]amine
6626 | Dalton Trans., 2008, 6624–6627
This journal is
The Royal Society of Chemistry 2008
©

View Article Online
Zhu, Z. Jin, Y.-Y. Ji, J.-W. Ye, M. Xue, H. Yang, Y. Wang and S.-L.
Qiu, Angew. Chem., Int. Ed., 2007, 46, 6638–6642; (c) C. Pariya, C. R.
Sparrow, C.-K. Back, G. Sand´ı, F. R. Fronczek and A. W. Maverick,
Angew. Chem., Int. Ed., 2007, 46, 6305–6308; (d) C. Schmuck, Angew.
Chem., Int. Ed., 2007, 46, 5830–5833; (e) F. Hof, S. L. Craig, C.
Nuckolls and J. Rebek, Jr., Angew. Chem., Int. Ed., 2002, 41, 1488–
1508; (f) L. R. MacGillivray and J. L. Atwood, Angew. Chem., Int.
Ed., 1999, 38, 1018–1033; (g) D. L. Caulder and K. N. Raymond,
J. Chem. Soc., Dalton Trans., 1999, 1185–1200; (h) A. Jasat and J. C.
Sherman, Chem. Rev., 1999, 99, 931–968; (i) J. de Mendoza, Chem.–
Eur. J., 1998, 4, 1373–1377; (j) M. Fujita, Chem. Soc. Rev., 1998, 27, 417–
425; (k) C. J. Jones, Chem. Soc. Rev., 1998, 27, 289–299; (l) J. W. Steed,
J. L. Atwood, Supramolecular Chemistry, John Wiley & Sons, Ltd., UK,
2000.
Bis{tris[2-(N-benzyldithiocarbamate)ethyl]amino}
diphenyl-
tin(IV) 5. To a solution of tris[2-(benzyl)ethyl] amine (0.100 g,
0.24 mmol) and potassium hydroxide (0.040 g, 0.72 mmol) in
methanol (5 ml) carbon disulfide (0.2 mL, 3.3 mmol) was added,
and the solution was stirred at 20 ◦C for 1 hour. A solution of
Ph2SnCl2 (0.124 g, 0.36 mmol g) in methanol (5 ml) was added
and the resulting precipitate was collected by filtration. The solid
was recrystallized in a mixture of chloroform–benzene giving
crystals suitable for X-ray crystallography. (Yield 0.070 g, 13.4%).
◦
Mp 229–231 C (from chloroform–benzene). Elemental analysis
(Found: C, 54.7; H, 4.8; N, 5.8; Calc. for C96H96N8S12Sn3: C, 54.8;
H, 4.6; N, 5.3). IR (KBr) nmax/cm-1 954 and 979 (CS2), 1477
(N-CS2). dH (400 MHz; CDCl3; Me4Si; COSY) 2.85–2.90 (12H,
m, CH2NCS2), 2.96 (6H, m, N(1)CHB), 3.91 (6H, m, N(1)CHA)
4.75 (6H, d, JAB = 15.2, NCHAPh), 5.34 (6H, d, JAB = 15.2,
NCHBPh), 7.19–7.23 (12H, m, CHo of NCH2Ph), 7.28–7.32
(18H, m, CHm,p, of CH2Ph), 7.33–7.39 (18H, m, CHo,p of
SnPh2), 7.81–7.85 (12H, m, CHo of SnPh2). dC (400 MHz;
CDCl3; Me4Si, HETCOR), 49.66 (CH2NCS2), 54.10 (N(1)CH2),
61.49 (NCH2Ph); [128.35 (Cm), 128.48 (Cp), 133.96 (Co), 153.24
(Ci), SnPh2]; [127.81 (Cm), 128.87 (Cp), 129.17 (Co), 134.58 (Ci),
CH2Ph], 202.13 (CS2). dSn (400 MHz; CDCl3; Me4Sn) 512. m/z
(FAB+) 2025 (M+ - C6H5, 5%).
2 (a) J. Cookson and P. D. Beer, Dalton Trans., 2007, 1459–1472; (b) K. D.
Karlin, Progress in Inorganic Chemistry, John Wiley & Sons, New
Jersey, 2005, vol. 53.
3 (a) W. W. H. Wong, D. Curiel, S.-W. Lai, M. G. B. Drew and P. D. Beer,
Dalton Trans., 2005, 774–781; (b) W. W. H. Wong, D. Curiel, A. R.
Cowley and P. D. Beer, Dalton Trans., 2005, 359–364; (c) W. W. H.
Wong, D. E. Phipps and P. D. Beer, Polyhedron, 2004, 23, 2821–2829;
(d) M. D. Pratt and P. D. Beer, Tetrahedron, 2004, 60, 11227–11238;
(e) P. D. Beer, N. Berry, M. G. B. Drew, O. D. Fox, M. E. Padilla-Tosta
and S. Patell, Chem. Commun., 2001, 199–200; (f) O. D. Fox, M. G. B.
Drew, E. J. S. Wilkinson and P. D. Beer, Chem. Commun., 2000, 391–
392; (g) O. D. Fox, M. G. B. Drew and P. D. Beer, Angew. Chem., Int.
Ed., 2000, 39, 136–140.
4 (a) P. D. Beer, A. G. Cheetham, M. G. B. Drew, O. D. Fox, E. J. Hayes
and T. D. Rolls, Dalton Trans., 2003, 603–611; (b) P. D. Beer, N. G.
Berry, A. R. Cowley, E. J. Hayes, E. C. Oates and W. W. H. Wong,
Chem. Commun., 2003, 2408–2409.
4.3 X-Ray crystallography
5 (a) V. Chandrasekhar, K. Gopal and P. Thilgar, Acc. Chem. Res., 2007,
40, 420–434; (b) V. Chandrasekhar, S. Nagendran and V. Baskar, Coord.
Chem. Rev., 2002, 235, 1–52; (c) R. R. Holmes, Acc. Chem. Res., 1989,
22, 190–197.
X-Ray diffraction studies were performed on a Bruker-APEX
diffractometer with a CCD area detector (lMoKa = 0.71073 A,
˚
monochromator: graphite). Frames were collected at 293 K for
compounds 1 and 4 and 100 K for compound 5 via w/f-rotation at
10 s per frame (SMART).11a The measured intensities were reduced
to F2 and corrected for absorption with SADABS (SAINT-NT).11b
Corrections were made for Lorentz and polarization effects.
Structure solution, refinement and data output were carried out
with the SHELXTL-NT program package.11c,d Non hydrogen
atoms were refined anisotropically, while hydrogen atoms were
placed in geometrically calculated positions using a riding model.
In compound 4 the central nitrogen N(2) lies on a threefold axis
and the unique Sn(1) atom on a twofold axis. In compound 5 the
central nitrogens N(2) and N(4) lie on a threefold axis. Solvent
molecules are present in the crystal lattices of compounds 4 and 5
(bromoform for 4, benzene and chloroform for 5). All three com-
pounds have elongated ellipsoids on the phenyl groups, suggesting
large vibration of the rings and/or disorder. For compound 5
the unit cell contains two capsules (Z = 2), which are localized at
crystallographic C3 axes, six benzene molecules, and four CHCl3
molecules at two crystallographically independent positions. One
of the two crystallographically independent CHCl3 molecules is
disordered (three different orientations with crystallographic C3-
symmetry, occ = 0.25, 0.25 and 0.50). The disorder has been treted
using DFIX, DANG, and EADP instructions.
6 (a) H. D. Yin and S. C. Xue, Appl. Organomet. Chem., 2006, 20, 283–
289; (b) S. Xue, H. Yin, Q. Wang and D. Wang, Heteroat. Chem.,
2005, 16, 271–276; (c) D. Dakternieks, H. Zhu, D. Masi and C. Mealli,
Inorg. Chem., 1992, 31, 3601–3606; (d) O.-S. Jung, Y. S. Sohn and J. A.
Ibers, Inorg. Chem., 1986, 25, 2273–2275; (e) H. L. M. van Gaal, J. W.
Diesveld, F. W. Pijpers and J. G. M. van der Linden, Inorg. Chem., 1979,
18, 3251–3260.
7 R. Reyes-Mart´ınez, R. Mejia-Huicochea, A. A. Guerrero-Alvarez, H.
Ho¨pfl and H. Tlahuext, Arkivoc, 2008, V, 19.
8 (a) P. D. Beer and E. J. Hayes, Encyclopedia of Supramolecular
Chemistry, Marcel Dekker. Inc., New York, 2004, 1006; (b) Z. R. Bell,
J. C. Jeffery, J. A. McCleverty and M. D. Ward, Angew. Chem., Int.
Ed., 2002, 41, 2515–2518; (c) A. Ikeda, H. Udzu, Z. Zhong, S. Shinkai,
S. Sakamoto and K. Yamaguchi, J. Am. Chem. Soc., 2001, 123, 3872–
3877; (d) A. Ikeda, M. Yoshimura, H. Udzu, C. Fukuhara and S. J.
Shinkai, J. Am. Chem. Soc., 1999, 121, 4296–4297; (e) R. Altmann,
O. Gausset, D. Horn, K. Jurkschat, M. Schu¨rmann, M. Fontany and
P. Zanello, Organometallics, 2000, 19, 430–443; (f) C. R. Woods, M.
Benaglia, F. Cozzi and J. S. Siegel, Angew. Chem., Int. Ed. Engl., 1996,
35, 1830–1833.
9 (a) O. Mamula, A. von Zelewsky and G. Bernardinelli, Angew. Chem.,
Int. Ed., 1998, 37, 289–293; (b) L. J. Prins, J. Huskens, F. de Jong,
P. Timmerman and D. N. Reinhoudt, Nature, 1999, 398, 498–502;
(c) L. R. MacGillivray and J. L. Atwood, Nature, 1997, 389, 469–472;
(d) L. J. Charbonniere, G. Bernardinelli, C. Piguet, A. M. Sargeson
and A. F. Williams, J. Chem. Soc., Chem. Commun., 1994, 1419–1420;
(e) B. Hasenknopf, J.-M. Lehn, B. O. Kneisel, G. Baum and D. Fenske,
Angew. Chem., Int. Ed. Engl., 1996, 35, 1838–1849.
10 (a) S. Chandra, R. J. Magee and B. D. James, Main Group Met. Chem.,
1988, 11, 57–65; (b) D. A. Brown, W. K. Glass and M. A. Burke,
Spectrochim. Acta, Part A, 1976, 32, 137–143; (c) G. Durgaprasad,
D. N. Sathyanarayana and C. C. Patel, Can. J. Chem., 1969, 47, 631–
635.
11 (a) Bruker Analytical X-ray Systems. SMART: Bruker Molecular
Analysis Research Tool, Versions 5.057 and 5.618, 1997 and 2000;
(b) Bruker Analytical X-ray Systems. SAINT + NT, Versions 6.01 and
6.04, 1999 and 2001; (c) G. M. Sheldrick, SHELX,86, Program for
Crystal Structure Solution, University of Go¨ttingen, Germany, 1986;
(d) Bruker Analytical X-ray Systems. SHELXTL-NT Versions 5.10
and 6.10, 1999 and 2000.
Acknowledgements
The authors thank CONACyT for a fellowship (186819, RRM)
and financial support through project No. SEP-2004-C01-47347.
References
1 (a) K. Uemura, Y. Yamasaki, Y. Komagawa, K. Tanaka and H. Kita,
Angew. Chem., Int. Ed., 2007, 46, 6662–6665; (b) Q.-R. Fang, G.-S.
This journal is
The Royal Society of Chemistry 2008
Dalton Trans., 2008, 6624–6627 | 6627
©