Reactions of in situ generated hydrated organotin cations with chelating O,O- or O,N-ligands: A possible structure-directing influence of the organic substituent on tin

Article abstract of DOI:10.1039/c003339a

The reaction of [n-Bu₂SnO]_n with 1,5- naphthalenedisulfonic acid tetrahydrate in a 1:1 stoichiometry followed by reaction with 2,2′-bipyridine-N,N′-dioxide (BPDO-I) afforded a 1D-coordination polymer [n-Bu₂Sn(BPDO-I)(1,5-C₁₀H ₆(SO₃)₂)]_n (1) where the disulfonate ligand acts as a bridging ligand between two tin centers. An analogous reaction involving [Ph₂SnO]_n afforded a trihydrated O,O′-chelated diorganotin cation [{Ph₂Sn(BPDO-I)(H ₂O)₃}²⁺][C₁₀H₆(SO ₃^-)₂]·2CH₃OH (2·2CH₃OH). Utilizing two equivalents of BPDO-I in this reaction resulted in the ionic complex [{Ph₂Sn(BPDO-I) ₂(H₂O)}²⁺][C₁₀H₆(SO ₃^-)₂]·3H₂O (3·3H ₂O). In 2 and 3 the sulfonate ligands are not present in the coordination sphere of tin. Reaction of [n-Bu₂SnO]_n and 1,5-naphthalenedisulfonic acid tetrahydrate, followed by reaction with [bis(diphenylphosphoryl)methane (DPPOM)] resulted in the formation of, [{n-Bu₂Sn(DPPOM)₂(H₂O)(1,5-C₁₀H ₆(SO₃)(SO₃^-)}]·H ₂O (4·H₂O). Of the two coordinating groups present in DPPOM, only one PO group is coordinated to the tin atom. The remaining PO motif is free and is involved in intramolecular H-bonding with the tin-bound water molecule. Using [Ph₂SnO]_n instead of [n-Bu ₂SnO]_n afforded the ionic complex [{Ph ₂Sn(DPPOM)₂}²⁺{1,5-C₁₀H ₆(SO₃^-)₂}] (5) where the DPPOM functions as a chelating ligand. The reaction of [n-Bu₂SnO] _n with 1,5-naphthalenedisulfonic acid tetrahydrate followed by addition of one equivalent of 8-hydroxyquinoline (8-HQ) in presence of triethylamine afforded the neutral dinuclear complex, [(H₂O)(8-Q)n- Bu₂Sn(μ-1,5-C₁₀H₆(SO₃) ₂)n-Bu₂Sn(8-Q)(H₂O)] (6) where the two tin atoms are bridged by the disulfonate ligand. Compounds 1-6 are thermally stable as shown by their thermogravimetric analyses.

Full text of DOI:10.1039/c003339a

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PAPER
Reactions of in situ generated hydrated organotin cations with chelating
O,O- or O,N-ligands: a possible structure-directing influence of the
organic substituent on tin†‡
Vadapalli Chandrasekhar* and Puja Singh
Received 17th February 2010, Accepted 5th October 2010
DOI: 10.1039/c003339a
The reaction of [n-Bu2SnO]n with 1,5-naphthalenedisulfonic acid tetrahydrate in a 1 : 1 stoichiometry
followed by reaction with 2,2¢-bipyridine-N,N¢-dioxide (BPDO-I) afforded a 1D-coordination polymer
[n-Bu2Sn(BPDO-I)(1,5-C10H6(SO3)2)]n (1) where the disulfonate ligand acts as a bridging ligand
between two tin centers. An analogous reaction involving [Ph2SnO]n afforded a trihydrated O,O¢-
2+
-
chelated diorganotin cation [{Ph2Sn(BPDO-I)(H2O)3} ][C10H6(SO3 )2]·2CH3OH (2·2CH3OH).
Utilizing two equivalents of BPDO-I in this reaction resulted in the ionic complex [{Ph2Sn(BPDO-I)2-
2+
-
(H2O)} ][C10H6(SO3 )2]·3H2O (3·3H2O). In 2 and 3 the sulfonate ligands are not present in the
coordination sphere of tin. Reaction of [n-Bu2SnO]n and 1,5-naphthalenedisulfonic acid tetrahydrate,
followed by reaction with [bis(diphenylphosphoryl)methane (DPPOM)] resulted in the formation of,
-
[{n-Bu2Sn(DPPOM)2(H2O)(1,5-C10H6(SO3)(SO3 )}]·H2O (4·H2O). Of the two coordinating groups
present in DPPOM, only one P O group is coordinated to the tin atom. The remaining P O motif is
free and is involved in intramolecular H-bonding with the tin-bound water molecule. Using [Ph2SnO]n
2+
-
instead of [n-Bu2SnO]n afforded the ionic complex [{Ph2Sn(DPPOM)2} {1,5-C10H6(SO3 )2}] (5) where
the DPPOM functions as a chelating ligand. The reaction of [n-Bu2SnO]n with 1,5-naphthalenedisul-
fonic acid tetrahydrate followed by addition of one equivalent of 8-hydroxyquinoline (8-HQ) in
presence of triethylamine afforded the neutral dinuclear complex, [(H2O)(8-Q)n-Bu2Sn(m-1,5-C10H6-
(SO3)2)n-Bu2Sn(8-Q)(H2O)] (6) where the two tin atoms are bridged by the disulfonate ligand.
Compounds 1–6 are thermally stable as shown by their thermogravimetric analyses.
anion the Lewis acidity of the tin center can be varied. It was
Introduction
also observed that the strength of the intramolecular coordination
by ‘Y’ concomitantly increases as the the nucleophilicity of X
decreases.4 For diorganotin compounds of the general formula
LSnPhX2 (L = 2,6-(Me2NCH2)2C6H3 or 2,6-(MeOCH2)2C6H3),
while neutral complexes were formed with X = Cl, it was possible
to stabilize hydrated and dehydrated diorganotin cations with
There has been a lot of interest in the area of organometal-
lic cations in general and organotin cations in particular in
recent years.1 Lewis acidic organotin cations are known to
be efficient catalysts for esterification and transesterification
reactions and more recently have found applications in C–C
coupling reactions.2,5b Several strategies have been employed to
stabilize organotin cations. A few research groups have employed
C,Y- or Y,C,Y-chelating ligands (Y = N or O) to stabilize di-
and triorganotin cations.3,4 For triorganotin compouds of type
Ph2L1,2SnX, it was found that depending on the nature of the
triflate (CF3SO3 )3a and monocarbaborane [(1-CB11H12)-] anions
-
respectively.3b
Hydrated organotin cations are another type of compounds,
among the broad class of organotin cations, that have been
recently receiving attention.2e,5,10 These have been suggested as
possible intermediates in the hydrolysis reactions of organotin
halides,6 the eventual products of which are organotin hydroxides,
hydroxide-oxides or oxides. The latter are important precursors
for the assembly of a variety of organostannoxanes.7 We have
observed that the reaction of diorganotin oxides such as [n-
Bu2SnO]n with arylsulfonic acids such as 2,5-Me2C6H3SO3H
in a 1 : 2 stochiometry affords hydrated organotin cations [n-
Bu2Sn(H2O)4][2,5-Me2C6H3SO3]2 (I).5b Other types of hydrated
organotin cations have since been synthesized using similar
procedures. We and others have examined the possibility of ligand
Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur-
208016, India. E-mail: vc@iitk.ac.in; Fax: (+91) 521-259-0007 / 7436;
Tel: (+91) 512-259-7259
† Dedicated to Professor H. W. Roesky on the occasion of his 75th birthday.
‡ Electronic supplementary information (ESI) available: Crystallographic
information files (CIF) for compounds 1–6, UV-visible and emission
spectrum of 6, Tables containing crystallographic data collection and
refinement parameters of compounds 1–6, thermogravimetric curves for
compound 1–6, additional figures and table. CCDC reference numbers
766494–766499. For ESI and crystallographic data in CIF or other
electronic format see DOI: 10.1039/c003339a
114 | Dalton Trans., 2011, 40, 114–123
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Scheme 1 Synthesis of (a)1, (b) 2 and (c) 3.
2+
-
exchange reactions on I by different types of ligands. While
Beckmann and co-workers were able to effect ligand exchange
using phosphine oxide ligands,8a we have found that use nitrogen
ligands can lead to ligand exchange or deprotonation reactions.8b
In view of the lower basicity of the N-oxide/P-oxide ligands,
it was of interest to probe these reactions using chelating N-
oxide/P-oxide ligands. More recently we have observed that use
of linear bifunctional N-oxide/P-oxide ligands afford a series of
solids with 1D–3D structures.9 Another point of interest was to
explore if the organic substituent on tin has any role in the eventual
product formed particularly in terms of directing the sulfonate
ligand to coordinate to tin or to render it non-coordinating.
Previously, Otera and coworkers have indicated a possible role
of the organic substituent on the type of hydrated organ-
otin cation isolated. Thus, the salt [{t-Bu2Sn(OH)(OTf)(H2O)}2,
{((S)-2-Phenylbutyl)2Sn(OH)(OTf)(H2O)}2], or neutral [{n-
Bu2Sn(OH)(OTf)(H2O)}2] compounds were obtained in identical
reaction conditions.10
Sn(BPDO-I)2(H2O)} {1,5-C10H6(SO3 )2}]·3H2O (3·3H2O), [n-
Bu2Sn(DPPOM)2(H2O)(1,5-C10H6(SO3)2)]·H2O (4·H2O), and
2+
-
[{Ph2Sn(DPPOM)2} {1,5-C10H6(SO3 )2}] (5) (Scheme 1–2),
among which 2 represents the first example of the structural
characterization of a hydrated diphenyltin cation. In addition
to O,O-chelating ligands we have also used a N,O chelating
ligand, 8-hydroxyquinoline (8-HQ), and isolated the dinuclear tin
compound, [n-Bu2Sn(8-Q)(H2O)(1,5-C10H6(SO3)2)(H2O)(8-Q)n-
Bu2Sn] (6) (Scheme 3) Examination of the crystal structures of
these compounds revealed interesting supramolecular assemblies.
In this paper we report the reactions of in situ generated
hydrated organotin cations with O,O¢ chelating ligands:
BPDO-I (2,2¢-bipyridine-N,N¢-dioxide) and DPPOM (bis-
(diphenylphosphoryl)methane). The type of final product seems to
be influenced by the nature of the substituent on tin (R = n-Bu and
Ph). Accordingly, herein, we describe the synthesis and structure
of [n-Bu2Sn(BPDO-I)(1,5-C10H6(SO3)2)]n (1), [{Ph2Sn(BPDO-
-
Scheme 2 Synthesis of (a) 4 and (b) 5.
I)(H2O)3}{1,5-C10H6(SO3 )2}]·2CH3OH (2·2CH3OH), [{Ph2-
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isolate this species have not been successful. However, previously,
using [n-Bu2SnO]n under similar reaction conditions we were
unable to introduce two chelating O,O-BPDO-I ligands in the
coordination sphere of tin.
In order to examine the product preference upon changing the
nature of the chelating ligand, we carried out above experiments in
presence of DPPOM as the chelating ligand. Previous literature
reveals the use of chelating DPPOM ligand in forming neutral
organotin adducts, although only few structurally character-
ized examples are known.11 Reaction of [n-Bu2SnO]n and 1,5-
naphthalenedisulfonic acid tetrahydrate, followed by addition of
DPPOM (Sn:L = 1 : 2; L = DPPOM) resulted in the forma-
-
tion of, [{n-Bu2Sn(DPPOM)2(H2O)(1,5-C10H6(SO3)(SO3 )}]·H2O
(4·H2O) (Scheme 2a). In this case, two molecules of DPPOM are
present in the coordination sphere of tin; however, only one of the
two ‘P O’ groups of each DPPOM is coordinated to the tin atom.
The remaining ‘P O’ motif is free and involved in intramolecular
H-bonding with the tin-bound water molecule as discussed vide
infra. Importantly, in this case also the sulfonate ligand is involved
in coordination to tin, although only through one end. The other
‘SO3’ group is free and anionic leaving a unit positive charge on
the tin atom, resulting in a zwitter ionic complex. The structural
difference between 1 and 4 is quite striking. The presence of
the bulkier DPPOM in 4 probably prevents the intermolecular
bridging coordination of the disulfonate ligand and hence the for-
mation of a coordination polymer. Using [Ph2SnO]n instead of [n-
Scheme 3 Preparation of 6.
Results and discussion
Synthesis
The general synthetic procedure for the preparation of compounds
1–6 involved the initial reaction of the diorganotin oxide [R2SnO]n
(R = n-Bu or Ph) with 1,5-naphthalenedisulfonic acid tetrahydrate
in a 1 : 1 stoichiometry. The in situ generated hydrated organotin
2+
-
cation [{R2Sn(H2O)x} {1,5-C10H6(SO3 )2}] (x = 4 or 5) was then
reacted with the chelating O,O- or O,N ligand affording com-
pounds 1–6 (Schemes 1–3). In case of 1, 2·2CH3OH, 4·H2O and
5, the resultant products were insoluble white solids which were
recrystallized by taking a suspension of the solid in methanol and
subsequently adding a minimum volume of acidified water (0.1 N
H2SO4; pH = 1.33) to afford a clear solution which was allowed to
evaporate at room temperature. While compound 3·3H2O showed
limited solubility, 6 was found to be highly soluble in methanol.
The reaction of [n-Bu2SnO]n with 1,5-napthalenedisulfonic
acid tetrahydrate in 1 : 1 stoichiometry, followed by the addi-
tion of 1 equivalent of BPDO-I allowed the isolation of [n-
Bu2Sn(BPDO-I)(1,5-C10H6(SO3)2)]n (1) (Scheme 1(a)), which is
a one-dimensional coordination polymer with the disulfonate
ligand acting as the bridging unit between two tin centers.
This reaction behavior is similar to that observed for the
2+
Bu2SnO]n afforded the ionic complex [{Ph2Sn(DPPOM)2} {1,5-
-
C10H6(SO3 )2}] (5), [Scheme 2(b)] where the sulfonate group is kept
out of the coordination sphere and two chelating DPPOM ligands
are present around tin. The low solubility of 2–5 prevented the
observation of signals in their 119Sn NMR spectra. Reactions of
above mentioned diorganotin oxides with BPDO-I and DPPOE
in other stoichiometries could not be isolated.
Anticipating that the use of stronger anionic chelation might
keep disulfonate out of coordination environment of tin for
‘R’ = n-Bu, we carried reaction of [n-Bu2SnO]n with 1,5-
naphthalenedisulfonic acid tetrahydrate followed by addition of
one equivalent of 8-HQ in presence of triethylamine as base.
This reaction afforded neutral dimeric 6, [(H2O)(8-Q)n-Bu2Sn(m-
1,5-C10H6(SO3)2)n-Bu2Sn(8-Q)(H2O)] (Scheme 3). At the same
time, formation of triethylammonium 1,5-naphthalenesulfonate
was observed. The inclusion of 1,5-naphthalenedisulfonate as a
bridging ligand underscores the influence of the n-butyl sub-
stituent. We were unable to obtain a characterizable product
under similar reaction conditions using [Ph2SnO]n. Previously, we
had reported a dimeric hydrated dication [{n-Bu2Sn(H2O)3(C10H6-
2+
diorganotin cation [{n-Bu2Sn(H2O)4} {2,5-Me2C6H3SO3}2] with
1
1,10-phenanthroline.8b The 119Sn{ H} NMR spectrum of 1, in
(CD3)2SO showed a singlet at -384.5 ppm indicative of 2C, 4O
coordination environment around the central tin atom.7a,7b It
was not possible to isolate the product, using the stoichiometry
Sn:BPDO-I 1 : 2 in this reaction. Using [Ph2SnO]n as the diorgan-
otin oxide precursor, under similar reaction conditions, afforded
a trihydrated O,O¢-chelated diorganotin cation [{Ph2Sn(BPDO-
2+
-
1,5-(SO3)2)(H2O)3n-Bu2Sn} {C10H6-1,5-(SO3 )2}] which does not
contain any ancillary chelating ligands.5c The 119Sn NMR spectra
of 6 in CD3OD showed two closely spaced broad resonances at
-216 and -218 ppm suggesting some sort of fluxional behavior.
The fluxionality may be attributed to either the coordination
exchange between the tin bound water molecules and the CD3OD,
or the release of disulfonate ligand, generating a species of type
[(H2O)(8-Q)n-Bu2Sn(CD3OD)]+, though the exact species involved
could not be ascertained.
2+
-
I)(H2O)3} ][C10H6(SO3 )2]·2CH3OH (2·2CH3OH) (Scheme 1(b)).
In this compound the sulfonate ligand is kept out of the coordina-
tion sphere of the tin. The three water molecules bound to tin are
present in the same plane and are involved in hydrogen-bonding
interactions with the disulfonate anions. Changing the Sn:L (L =
BPDO-I) stoichiometry to 1 : 2 resulted in the incorporation of
two chelating ligands and the ionic complex [{Ph2Sn(BPDO-
2+
-
I)2(H2O)} ][C10H6(SO3 )2] (3)(Scheme 1(c)) was obtained as its
trihydrate 3·3H2O. Interestingly, one molecule of water was still
retained in the coordination sphere of tin, raising the possibility
that the in situ generated hydrated organotin cation in this case
The UV-visible absorption of the free 8-HQ ligand falls in the
range 270–340 nm.12 Among metal complexes of 8-HQ ligand,
tris(8-hydroxyquinoline)aluminium (Alq3) is well known, and
is used as an emitting material in organic light emitting diodes
-
might be [Ph2Sn(H2O)52+][C10H6(SO3 )2], although attempts to
116 | Dalton Trans., 2011, 40, 114–123
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(OLEDs) [Although 8-HQ ligand itself is weakly fluorescent
because of the excited state intramolecular proton transfer
(ESIPT) of the proton of ‘OH’ function to the ‘N’ of pyridine
moiety, its metal complexes are stable and fluoresecent]. The
UV-visible absorption spectrum of Alq3 (in CH2Cl2 solution)
shows peaks at 384, 334(sh) and 320(sh); the emission maxima
for this compound is seen at 516 nm.12c Compound 6 shows
a strong absorption at 376 nm (Figure S1(a), Supporting
Information‡) which is assigned to a p–p* charge transfer from
the electron rich phenoxide ring to the electron deficient pyridyl
ring. The fluorescence spectrum of 6 (Figure S1(b), Supporting
Information‡) revealed a red-shifted emission peak at 548 nm
using an excitation wavelength lmax = 376 nm.
Fig. 1 1D-coordination polymer of 1. n-Butyl groups and all the hydrogen
atoms have been omitted for clarity.
Molecular and crystal structures§
(Figure S3(a); Supporting Information‡). The Sn–O distances
[n-Bu2Sn(BPDO-I)(1,5-C10H6(SO3)2)]n (1). The asymmet-
ric unit of 1 ((Figure S2; Supporting Information‡) contains
one tin atom, two n-butyl groups, one BPDO-I ligand and one
1,5-naphthalenedisulfonate ligand. The crystal structure of 1 is
shown in Fig. 1 which reveals it to be a zig-zag one-dimensional
coordination polymer. Selected bond distances and -angles of
1 are given in Table S4A of Supporting Information‡. The
repeat unit of 1 contains a hexacoordinated tin center (2C, 4O)
possessing a distorted octahedral geometry. The coordination
environment around tin contains two oxygen atoms (O1 & O2)
of the chelating BPDO-I, two oxygen atoms (O3 & O6) of two
1,5-naphthalenedisulfonate ligands (which are coordinated in a
cis manner). The remaining two sites are occupied by two trans
˚
(those involving BPDO-I ligand) are 2.234(3) A (Sn1–O1) and
˚
2.220(3) A (Sn1–O2). The Sn–O bond distances pertaining to the
˚
˚
sulfonate ligands (Sn1–O3 2.257(3) A; Sn1–O6 2.267(3) A), clearly
indicate a much stronger sulfonate coordination to the tin rela-
tive to that found in [{n-Bu2Sn(H2O)3(1,5-C10H6-(SO3)2)(H2O)3n-
-
5c
˚
Bu2Sn}{1,5-C10H6(SO3 )2}] (2.515(6) A). On viewing a cross-
section of 1 across the ab plane (Figure S3(c); Supporting
Information‡), it becomes evident that the adjacent 1D-chains
are arranged in a criss-cross manner. The dihedral angle between
planes of two adjacent chains is 70.07(6)◦ (Figure S3(b); Sup-
porting Information‡)). These chains are stitched together by C—
H ◊ ◊ ◊ O and p ◊ ◊ ◊ p interactions (N1 C9–C13, C19–C23 pcent ◊ ◊ ◊ pcent
˚
3.67(6) A). Another set of C–H ◊ ◊ ◊ O bonds between chains of
n-butyl groups. The two aromatic rings of BPDO-I ligand are
similar orientation contribute to strengthen the three dimensional
◦
twisted with respect to each other [torsion angle = 65.40 (2)
]
˚
supramolecular structure of 1 (C11–H11ctdoct;O7 2.460(5) A)
(Figure S3(d); Supporting Information‡). The complete set of
metric parameters of the hydrogen bonding interactions in 1 are
summarized in Table S4B of Supporting Information‡.
§ Crystal data for 1: C28H32N2O8S2Sn, M = 707.37, monoclinic, a =
◦
◦
˚
˚
˚
25.099(◦5) A, b = 15.666(5) A, c = 19.433(5) A, a = 90 , b = 129.327(5) ,
3
˚
g = 90 , V = 5911.57(4) A , T = 293(2) K, space group C2/c, Z =
8, 16015 reflections measured, 5781 unique (Rint = 0.0401) which were
used in all calculations; Final R indices are R1 [for I > 2s(I)] = 0.0452,
wR2 = 0.1254, R1[for all data] = 0.0543, wR2 = 0.1375. Crystal data for
[{Ph2Sn(BPDO-I)(H2O)3}{1,5-C10H6(SO3)2}]·2CH3OH
(2·
2CH3OH). The asymmetric unit of 2·2CH3OH contains half
of the molecule (Figure S4; Supporting Information‡). The
molecular structure of 2·2CH3OH is shown in Fig. 2 and its
important bond parameters are listed in Table S5A of Supporting
Information‡. The tin atom in this diorganotin cation is present
in a pentagonal bipyramidal geometry (2C, 5O coordination
˚
2·2CH3OH: C34H38N2O13S2Sn, M = 865.47◦, monoclinic, a = 18.2329(13) A,
◦
◦
˚
˚
b = 11.0763(8) A, c = 18.0241(13) A, a = 90 , b = 99.3740(10) , g = 90 , V =
3
˚
3591.4(4) A , T = 153(2) K, space group C2/c, Z = 4, reflections measured
9742, 3518 unique (Rint = 0.0237) which were used in all calculations. The
final R indices are R1 [for I > 2s(I)] = 0.0271, wR2 = 0.0654; R1 [for all
data] = 0.0289, wR2 = 0.0665. Crystal data for 3·3H2O: C42H40N4O14S2Sn,
˚
˚
˚
M = 1007.59,◦triclinic, a = 10.526(5) A, b = 11.739(5) A, c = 18.285(5) A,
◦
◦
3
˚
a = 92.530(5) , b = 103.242(5) , g = 100.479(5) , V = 2153.9(15) A , T =
293(2), space group P1, Z = 2, reflections measured 10866, 7408 unique
¯
(Rint = 0.0269) which were used in all calculations. The final R indices are
R1 [for I > 2s(I)] = 0.0474, wR2 = 0.1248, R1 [for all data] = 0.0577,
wR2 = 0.1361. Crystal data for 4·H2O: C68H72O12P4S2Sn, M = 1387.95,
◦
˚
˚
˚
monoclinic, a = 33.071(5) A, b = 11.224(5) A, c = 37.192(5) A, a = 90 , b =
◦
◦
3
˚
114.090(5) , g = 90 , V = 12603(6) A , T = 100(2) K, space group C2/c,
Z = 8, reflections measured 31925, 11069 unique (Rint = 0.0877) which
were used in all calculations. The final R indices are R1 [for I > 2s(I)] =
0.0592, wR2 = 0.1454, R1 [for all data] = 0.0913, wR2 = 0.1659. Crystal
˚
data for 5: C72H60O10P4S2Sn, M = 1391.89, monoclinic, a◦= 15.154(5) A,
◦
◦
˚
˚
b = 11.657(5) A, c = 19.051(5) A, a = 90 , b = 112.254(5) , g = 90 , V =
3
˚
3114.7(19) A , T = 100(2) K, space group P21/n, Z = 2, reflections measured
15603, 5471 unique (Rint = 0.0542) which were used in all calculations. The
final R indices are R1 [for I > 2s(I)] = 0.0440, wR2 = 0.1087, R1 [for all
data] = 0.0550, wR2 = 0.1229. Crystal data for 6: C44H58N2O10S2Sn2, M =
˚
˚
˚
1076.42, monoclini◦c, a = 25◦.783(5) A, b = 8.597(5) A, c = 24.133(5) A, a =
◦
3
˚
90 , b = 116.270(5) , g = 90 , V = 4796.8(3) A , T = 293(2) K, space group
Fig. 2 Molecular structure of 2. Hydrogen atoms are not shown.
Symmetry transformations used to generate equivalent atoms: N1*, O1*,
O2* -x + 1, y, -z + 1.5.
C2/c, Z = 4, reflections measured 14974, 5837 unique (Rint = 0.0514) which
were used in all calculations. The final R indices are R1 [for I > 2s(I)] =
0.0593, wR2 = 0.1599, R1 [for all data] = 0.1011, wR2 = 0.2125.
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environment). This is achieved by two oxygen atoms (O1 & O1*)
from BPDO-I, three oxygen atoms (O2, O3 & O2*) of three water
molecules and two carbon atoms (C1 & C1*) belonging to two
phenyl moieties. The dipositive charge on the cation is balanced
by one 1,5-naphthalenedisulfonate anion. It is interesting to note
that the three oxygen atoms of the three water molecules occupy
contiguous coordination positions in the equatorial plane. The
other two equatorial positions are also occupied by oxygen atoms
belonging to the BPDO-I ligand. Two types of Sn–Ow bond lengths
rise to a zig-zag supramolecular chain propagating along the
crystallographic c axis. The H-bonded 1D-polymeric chain thus
formed is illustrated in Fig. 3(a). The topological disposition of
this H-bonded chain resembles the coordination-driven 1D-chain
of 1. One of the oxygen atoms (O5) of the disulfonate groups
of one chain simultaneously forms a strong C–H ◊ ◊ ◊ O contact
˚
[C10–H10 ◊ ◊ ◊ O5 2.441(2) A] with the BPDO-I unit of an adjacent
chain resulting in a two- dimensional hydrogen bonded sheet,
parallel to the bc plane [Fig. 3(b)]. The region between consecutive
2D-sheets is occupied by uncoordinated methanol molecules
(C17, O7) present in the crystal lattice. These guest molecules
are held in position with the help of strong O–H ◊ ◊ ◊ O contacts
˚
are observed in 2·2CH3OH: 2.336(2) A (Sn1–O2 & Sn1–O2*) and
˚
˚
2.240(2) A (Sn1–O3). The average Sn–Ow distance of 2.288(2) A
is comparable with the average Sn–Owater bond length present
2+
-
˚
˚
in [{n-Bu2Sn(H2O)4} {2,5-Me2–C6H3–SO3 }2] (2.271(2) A).
O–H ◊ ◊ ◊ O hydrogen bonds exist between water molecules (O2,
O2* and O3) bonded to the tin centre, and two of the oxygens
(O5 and O6) of each ‘SO3’ moiety of disulfonate anion. This gives
(O4 ◊ ◊ ◊ O7 2.710(2) A), thereby assisting in glueing the sheets
together in a three dimensional assembly (Figure S5; Supporting
Information‡). Additionally, these sheets are interrelated through
another set of C–H ◊ ◊ ◊ O interactions between the oxygen atom
Fig. 3 (a) One dimensional H-bonded polymer of 2·2CH3OH. (b) Extension of 1D-chain of 2·2CH3OH (shown in Fig. 3a) into a 2D-layer across the ab
plane, aided by C—H ◊ ◊ ◊ O contacts (C10–H10 ◊ ◊ ◊ O5). Phenyl groups and all the hydrogen atoms (except those engaged in forming C–H ◊ ◊ ◊ O contacts)
have been omitted for clarity.
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(O4) of a disulfonate anion of one layer and a hydrogen atom
(H7) of BPDO-I of the adjacent layer. The bonding parameters
involving the hydrogen bonding interactions in 2·2CH3OH are
summarized in Table S5B of Supporting Information‡.
2+
-
[{Ph2Sn(BPDO-I)2(H2O)} {1,5-C10H6(SO3 )2}]·3H2O
(3·
3H2O). The molecular structure of 3·3H2O is depicted in Fig. 4.
Selected bond distances and bond angles are listed in Table
S6A of Supporting Information‡. Tin is present in a pentagonal
bipyramid geometry (2C, 5O) and its coordination sphere
contains two chelating molecules of BPDO-I, one molecule of
water and two phenyl groups. The latter are present trans to
each other in the axial positions. 1,5-naphthalelenedisulfonate is
present as an anion to balance the two positive charges on the
2+
cation {Ph2Sn(BPDO-I)2H2O)} .
Fig. 5 Molecular Structure of 4. ‘n-Butyl’ groups and hydrogen atoms
(except those belonging to the bound water molecule) have been omitted
for the sake of clarity.
interest to note that in the complex [n-Bu2Sn(DPPOM)Cl2] also
DPPOM behaves as a monodentate ligand.11a
Two molecules of 4 are brought in close proximity with the
help of multiple intermolecular C–H ◊ ◊ ◊ O and C–H ◊ ◊ ◊ p contacts,
forming a dimeric motif [Fig. 6]. The bond parameters involved in
these interactions are summarized in Table S7B of Supporting
Information‡. These dimers are further associated with each
other through another strong C–H ◊ ◊ ◊ O hydrogen bond, involving
one of the hydrogen atoms of the methylene group (C9) of
one of the DPPOM moieties and one of the oxygen atoms
Fig. 4 Molecular structure of 3. Hydrogen atoms are not shown.
˚
˚
The Sn–Owater (Sn1–O5) distance in this compound is 2.249(3) A,
while the Sn–OBPDO-I bond distances range from 2.270 to 2.370 A.
◦
˚
(O9) of disulfonate (C9–H9B ◊ ◊ ◊ O9 2.224(4) A, 158.41(34) ).
This interaction transforms the structure into a one-dimensional
supramolecular tape. Such tapes cross each other and are glued
together at the crossing points by C–H ◊ ◊ ◊ p contacts (Figure
S10(a); Supporting Information‡). The crosslinking of such chains
eventually leads to a three dimensional supramolecular network.
The asymmetric unit of 3 also contains three molecules of water
of crystallization (O12, O13 & O14) (Figure S6, Supporting
Information‡). Strong hydrogen bonding interactions exist be-
tween the water molecule (O5) bonded to the tin, one set of 1,5-
naphthalenedisulfonate anion (S2, O9 O10 & O11), and the lattice
water molecules (O12, O13 & O14) leading to the generation of
a 2D-hydrogen bonded layer parallel to the bc plane (Figure S7,
Table S6B; Supporting Information‡). Contribution of hydrogen
bonds from another set of 1,5-naphthalenedisulfonate anion (S1,
O6 O7 O8) takes the structure into a final three dimensional
assembly (Figure S8; Supporting Information‡).
[{n-Bu2Sn(DPPOM)2(H2O)(1,5-C10H6(SO3)(SO3)}]·H2O (4·
H2O). The molecular structure of 4·H2O is shown in Fig. 5.
It features an octahedrally coordinated (2C, 4O) tin center
surrounded by two oxygen atoms (O2 & O4) of two trans DPPOM
ligands, one oxygen atom (O1) of a bound water molecule, one
oxygen atom (O6) of the coordinated 1,5-napthalendisulfonate
ligand and two trans n-butyl groups. One free water molecule
present per asymmetric unit is disordered over two positions (O12
& O12a) (Figure S9, Supporting Information‡). Selected bond
lengths and -angles of 4·H2O are given in Table S7A of Supporting
˚
Information‡. The average Sn–ODPPOM distance is 2.204(4) A. The
Fig. 6 This figure illustrates multiple C–H ◊ ◊ ◊ O and C–H ◊ ◊ ◊ p in-
teractions driving the association of two molecules of 4 to form a
supramolecular dimer (metric parameters are listed in Table S7B of
Supporting Information‡). The tin bound phenyl groups and hydrogen
atoms (except those involved in C–H ◊ ◊ ◊ O and O–H ◊ ◊ ◊ O interactions,
have been omitted for the sake of clarity).
˚
Sn–Owater (Sn–O1) bond distance is 2.200(4) A and is intermediate
between two Sn–O distances involving tin atom and two bonded
‘P O’ groups (Sn1–O2 2.181(4) & Sn1–O4 2.227(4) A). One out
of P O motifs of each DPPOM (O3 & O5) is free and forms a
strong intramolecular H-bond with the coordinated water. It is of
˚
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Figure S10(b) of Supporting Information‡ illustrates a view of this
3D-assembly along the c axis, unveiling channels filled with water
molecules (disordered, O12 & O12A). These guest molecules are
held in the channels with the help of weak O–H ◊ ◊ ◊ O (O ◊ ◊ ◊ O range
another set of strong C–H ◊ ◊ ◊ O hydrogen bonds, forming a two-
dimensional architecture along the bc plane [Figure S12(a), Table
S8B; Supporting Information‡]. The structure propagates parallel
to the ac plane, aided by another set of C–H ◊ ◊ ◊ O contacts stitching
the 2D-layers in to a three-dimensional supramolecular structure
[Figure S12(b), Table S8B; Supporting Information‡].
˚
3.123–3.435 A) and C–H ◊ ◊ ◊ O (C34 ◊ ◊ ◊ O12 and C34 ◊ ◊ ◊ O12a,
˚
range 3.586–3.859 A) contacts with the free oxygen (O8) of one of
the ‘SO3’ moiety and protons of ‘methylene’ group (C34, DPPOM)
respectively.
[(H2O)(8-Q)n-Bu2Sn(l-1,5-C10H6(SO3)2)n-Bu2Sn(8-Q)(H2O)]
(6). The asymmetric unit of 6 contains half portion of the dimeric
molecule (Figure S13; Supporting Information‡). 6 is a neutral
dinuclear tin complex where the two tin centers are bridged by
a 1,5-naphthalenedisulfonate ligand (Fig. 8). Each tin atom is
present in a distorted octahedral geometry (2C, 1 N, 3O). The
coordination environment contains a chelating N,O- ligand (N1,
O1). The remaining coordination sites are taken up by a water
molecule (O5), one oxygen atom (O2) of the disulfonate ligand
and two n-butyl substituents.
2+
-
[{Ph2Sn(DPPOM)2} {1,5-C10H6(SO3 )2}] (5). 5 is a discrete
ionic complex (Fig. 7(a)). The asymmetric unit of 5 con-
tains one tin atom located on the centre of inversion (s.o.f
0.5), one phenyl moiety, one DPPOM ligand and half of
a 1,5-naphthalenedisulfonate anion (Figure S11; Supporting
Information‡). The cationic part of 5 contains a hexacoordinate
tin in an octahedral geometry. The two DPPOM ligands are
present in the equatorial plane with the two phenyl substituents
being present trans to each other. Selected bond lengths and bond
angles of 5 are given in Table S8A of Supporting Information‡.
Unlike the monodentate nature of DPPOM in 4·H2O, here both
the “P O” functionalities of each of the DPPOM molecules
are symmetrically coordinated to the tin centre. The average
˚
Sn–ODPPOM distance is 2.198(2) A (Sn1–O1 2.212(2); Sn1–O2
2.184(2)) and is comparable to the corresponding distance found in
˚
4·H2O (2.204(4) A, vide supra). Thus, shorter Sn–ODPPOM distances
found in both 4·H2O and 5 indicate relatively stronger binding
of DPPOM in the present instances than in neutral complexes
[Me2SnCl2(DPPOM)] (2.401(2) A),11a or [Ph2Sn(NO3)2(DPPOM)]
˚
Fig. 8 Association between adjacent molecules of the dinuclear complex
6 through O–H ◊ ◊ ◊ O contacts (O1 ◊ ◊ ◊ O5* 2.675(8) A; symmetry -x, y, -0.5
11b
˚
˚
(2.230(5) A).
Protons of the methylene groups of coordi-
- z; 0.5 - x, 0.5 - y, -z), extends along a axis forming a zig-zag 1D chain.
‘n-Butyl’ groups and hydrogen atoms are omitted for a clear view.
nated DPPOM ligands are quite acidic and one of them is
hydrogen bonded to one of the oxygen atoms (O5) of the
1,5-naphthalenedisulfonate anion, leading to strong C–H ◊ ◊ ◊ O
Selected bond lengths and bond angles of 6 are given
in Table S9 of Supporting Information‡. The Sn–Owater dis-
˚
bonds (C31–H31A ◊ ◊ ◊ O5 2.173(3) A) connecting the cationic units
into a one dimensional chain [Fig. 7(b)]. Additional C–H ◊ ◊ ◊ O
contacts between ‘O5¢ and phenyl groups of DPPOM [C8–
H8 ◊ ◊ ◊ O5 2.295(3); C18–H18 ◊ ◊ ◊ O5 2.500(3)] strengthen the 1D-
chain. Two such 1D-chains interact with each other through
˚
tance [Sn1–O5 2.309(5) A)] found in 6 is longer than that
˚
found in 4·H2O [Sn–Owater 2.200(4) A)]. The bond involv-
˚
ing tin and 1,5-naphthalenedisulfonate [Sn1–O2 2.424(5) A] is
also longer than the corresponding distance found in 4·H2O
˚
[2.267(4) A]. These Sn–Osulfonate distances found in 4·H2O
and 6 are shorter than that found in [{n-Bu2Sn(H2O)3(1,5-
2+
-
(C10H6(SO3)2)(H2O)3n-Bu2Sn} {1,5-(C10H6(SO3 )2}] [Sn–Osulfonate
5c
˚
2.515(6) A].
The supramolecular structure of 6 contains a 1D zig-zag
chain along the crystallographic c axis (Fig. 8). In this network,
adjoining dimers interact with each other through strong O–
H ◊ ◊ ◊ O hydrogen bonds between oxygen atom (O1) of 8-Q of one
molecule and water (O5*) bonded to tin atom of other molecule.
˚
The O1 ◊ ◊ ◊ O5* distance involved in this contact is 2.675(8) A.
Further, strong O–H ◊ ◊ ◊ O hydrogen bond between bonded water
molecule belonging to one chain and one of the non-bonding
oxygen atom (O3) of the disulfonate belonging to adjoining chain
˚
(O ◊ ◊ ◊ O 2.719(7) A), generates a two dimensional assembly parallel
to the ab plane (Figure S14; Supporting Information‡).
Thermogravimetric analysis of 1–6. Thermogravimetric curve
of 1 (Figure S15; Supporting Information‡) indicates the stability
Fig. 7 (a) Molecular structure of 5. (b) 1D-supramolecular chain of 5. Tin
bound ‘phenyls’ (only in Fig. 7(b)), and all the hydrogen atoms (excluding
those forming C–H ◊ ◊ ◊ O and O–H ◊ ◊ ◊ O contacts) are omitted for the sake
of clarity. Symmetry transformations used to generate equivalent atoms:
(C1*, O1*, O2*) -x + 2, -y + 2, -z.
◦
of this 1D-polymer till ~305 C. On the other hand, 2·2CH3OH
loses methanol molecules present in the crystal lattice and one-
third of its bound water molecules before ~150 ◦C (observed 9.4%;
calcd. 9.5%) (Figure S16; Supporting Information‡); the resultant
120 | Dalton Trans., 2011, 40, 114–123
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solid was found to be stable till ~215 ◦C. Thermal analysis of
3·3H2O (Figure S17; Supporting Information‡) revealed an initial
loss of three lattice water molecules, followed by one coordinated
water, accounting for a weight drop of ~7.7% in the temperature
range ~75 ◦C–150 ◦C (calcd. 7.1%). Thereafter decomposition
began at ~210 ◦C. Thermal analysis of 4·H2O and 5 are given
in Figures S18 and S19 respectively, of Supporting Information‡.
Complex 4·H2O showed no significant weight loss till ~175 ◦C. The
lattice water molecules were seemingly lost while drying 4 in vacuo.
A minor dip in the thermal curve of 4 at ~175–220 ◦C (weight loss
~1.7%) may be attributed to the loss of bonded water molecule
(calcd. 1.3%). The residue was apparently stable till ~290 ◦C where
decomposition was initiated. 5 revealed no significant weight loss
till ~325 ◦C, where weight loss was observed. Thermal degradation
of 6 (Figure S20; Supporting Information‡) began with an initial
weight loss of ~4.2% in the temperature range 75 ◦C–115 ◦C,
accounted by removal of bonded water molecules (calcd 3.3%).
The resultant solid was apparently stable prior to initiation of
its decomposition at ~275 ◦C. Thus, overall the thermal behavior
suggests good thermal stability for the 1D coordination polymer
1 and compound 5, while the other compounds are reasonably
stable.
using a JSGW melting point apparatus and are uncorrected.
Elemental analyses were carried out using a Thermoquest
CE instruments model EA/110 CHNS–O elemental analyzer.
Infrared spectra were recorded as KBr pellets on a FT-IR
Bruker-Vector Model. 1H and 119Sn NMR spectra were obtained
on a JEOL-DELTA2 500 model spectrometer using (CD3)2SO
with chemical shifts referenced to tetramethylsilane (for 1H NMR)
and tetramethyltin (for 119Sn NMR) respectively. 119Sn NMR
spectra were recorded under broad-band decoupled conditions.
Thermogravimetric analysis was carried out on a Perkin Elmer
Pyris 6 Thermogravimetric analyzer.
Synthesis
[n-Bu2Sn(BPDO-I)(1,5-C10H6(SO3)2)]n (1). A mixture of [n-
Bu2SnO]n (0.10 g 0.40 mmol) and 1,5-naphthalendisulfonic acid
tetrahydrate (0.15 g 0.41 mmol) was taken in a mixture of toluene–
methanol (16 mL, 5 : 3) and the contents were stirred at room
temperature for 3.5 h, affording a white precipitate. Subsequently,
one equivalent of BPDO-I (0.090 g, 0.40 mmol) was added.
The reaction mixture was allowed to react further for 24 h.
The resultant white solid was washed with methanol, acetone
and diethylether, and recrystallized from a solvent mixture of
methanol and acidified water to afford big block-like colorless
crystals of 1. Yield: 0.24 g (84%). M.p.: >250 ◦C. Anal. Calcd. for
C28H32N2O8S2Sn (708.06 g) (%): C 47.45, N 3.95, H 4.55; Found:
C, 47.25, N 3.99 H, 4.68. IR (KBr, cm-1):, 1120, 1164 [s, n(SO3)
asym. str.], 608 [s, n(C–S)]; 3103(m) 3083, 1479(m), 1376(m),
Conclusion
In situ generated hydrated organotin compounds have been used
as precursors in reactions with chelating O,O¢ or O,N¢ ligands.
Structural study of the resultant compounds indicated a subtle
structure-directing role for the organic substituent present on
tin. Thus, the presence of n-butyl substituents on tin appears
to favor the formation of neutral complexes by drawing the
sulfonate groups into the coordination sphere of tin (1, 4·H2O
and 6). Although [n-Bu2Sn(H2O)4][2,5-C6H3SO3]2 is an ionic
complex containing sulfonate anions that are not bound to tin,
presence of chelating co-ligands seems to force the sulfonate
groups into the coordination sphere of tin, the other example of
this type being, [{n-Bu2Sn(H2O)(Phen)(2,5-Me2C6H3SO3)}{2,5-
Me2C6H3SO3}] (Phen = 1,10-phenanthroline).8b On the other
hand, the phenyl substituents on tin seem to favor formation
of ionic complexes. A highlight of this study is the isola-
tion and structural characterization of a novel O,O¢ chelated
trihydrated diphenyltin cation, [{Ph2Sn(BPDO-I)(H2O)3}{1,5-
C10H6(SO3)2}]·2CH3OH. This is the first example of a hydrated
diphenyltin cation. It appears possible to use such a species for the
designed assembly of coordination driven supramolecular entities
such as molecular squares. We are exploring these possibilities.
1
832(m), 803(s), 720(s), 557(m) [BPDO-I]. H NMR (500 MHz,
(CD3)2SO): d = d = 8.74 (d, 2H, naphthyl-CH), 8.51–8.53 (dd,
2H, BPDO-I–CH), 7.80 (d, 2H, naphthyl-CH), 7.67–7.77 (m, 6H,
BPDO-I–CH), 7.35 (m, 2H, naphthyl-CH), 1.21–1.24 (m, 4H,
SnCH2), 1.43–1.52 (m, 8H, CH2CH2), 0.81 (t, 6H, CH3). 119Sn
NMR (500 MHz, (CD3)2SO): d = -384.5 ppm (s).
-
[{Ph2Sn(BPDO-I)(H2O)3}{1,5-C10H6(SO3 )2}]·2CH3OH (2·
2CH3OH). To a solution of 1,5-naphthalenedisulfonic acid
tetrahydrate (0.11 g 0.30 mmol) in 9 mL of methanol, was added
15 mL of dry toluene followed by [Ph2SnO]n (0.09 g 0.30 mmol).
The resultant mixture was stirred for 20 min and one equivalent
of BPDO-I (0.07 g, 0.30 mmol) was added. A clear solution
formed immediately. Subsequently a white solid precipitated
from the reaction mixture. The latter was allowed to stir at room
temperature for 60 h. The white precipitate obtained was filtered,
washed with 2 mL of methanol, acetone and diethylether, and
recrystallized using a combination of methanol and acidified
water, to afford big block-like crystals of 2·2CH3OH. Yield: 0.14 g
(52%). M.p.: >250 ◦C (d). Anal. Calcd. for C34H38N2O13S2Sn
(865.48 g) (%): C 47.11, N 3.23, H 4.42; Found: C 47.61, N 3.40,
H 4.56. IR (KBr, cm-1): 3469 [vbr, n(H2O)], 1196 [s, n(SO3) asym.
str.], 1157 [s, n(SO3) asym. str.], 1032 [s, n(SO3) sym. str.], 610
[s, n(C–S)], 3102(m,br) 3034(m, br) 1481(m) 1429(m) 1263(m)
1241(s) 846(m) 834(m) 813(m) 779(m) 766(m) 581(s) [BPDO-I].
1H NMR (500 MHz, ((CD3)2SO): d = 8.81 (d, 2H, naphthyl-CH),
8.27 (d, 4H, BPDO-I–CH), 7.87 (d, 2H, naphthyl-CH), 7.47
(m, 2H, naphthyl-CH), 7.70 (s, 2H, BPDO-I–CH), 7.64 (d, 2H,
BPDO-I–CH) 7.36 (m, 10H, Sn-phenyl-CH).
Experimental
General remarks
Solvents were distilled and dried prior to use according to standard
procedures.13 [n-Bu2SnO]n, [Ph2SnO]n, 1,5-naphthalenedisulfonic
acid
tetrahydrate,
1,2-diphenylphosphinomethane,
2,2¢-
bipyridine, 8-hydroxyquinoline (all from Aldrich) were
purchased and used as such without any further purification.
2,2¢-bipyridine-N,N-dioxide dihydrate (BPDO-I)14 and 1,2-
bis(diphenylphosphorylmethane) (DPPOM)15 were prepared
according to literature procedure. Melting points were measured
2+
-
[{Ph2Sn(BPDO-I)2(H2O)} {1,5-C10H6(SO3 )2}]·3H2O
(3·
3H2O). To solution of 1,5-napthalenedisulfonic acid
a
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tetrahydrate (0.12 g 0.30 mmol) in 9 mL of methanol was added
15 mL of dry toluene followed by [Ph2SnO]n (0.09 g 0.30 mmol).
The resultant mixture was stirred for 20 min and to this two
equivalents of BPDO-I (0.14 g, 0.60 mmol) was added. A clear
solution formed immediately followed by precipitation of a
white solid. The reaction mixture was allowed to stir further
for 48 h and filtered. The white precipitate was washed with
2 mL of diethylether, and recrystallized from methanol to afford
block-like, colorless crystals of 3·3H2O Yield: 0.20 g (64%). M.p.:
236 ◦C (d). Anal. Calcd. for C42H40N4O14S2Sn (1007.59 g) (%):
C 49.99, N 5.56, H 4.00; Found: C 50.21, N 5.67, H 4.12. IR
(KBr, cm-1): 3470 [br, n(H2O)], 1195 [s, n(SO3) asym. str.], 1159
[s, n(SO3) asym. str.], 1032 [s, n(SO3) sym. str.], 611 [s, n(C–S)],
3102(m,br) 3036(m,br) 1480(ms) 1428(s) 1263(m) 1243(s) 847(m)
835(m) 813(m) 798(m) 767(m) 581(ms) [BPDO-I]. 1H NMR
(500 MHz, (CD3OD): d = 8.95 (d, 2H, naphthyl-CH), 8.14 (d,
4H, BPDO-I–CH), 7.81 (b, 2H, naphthyl-CH), 7.43 (b, 2H,
naphthyl-CH), 7.08–7.37 (m, 22H, aromatic-CH).
7.50 (m, aromatic-CH), 7.34–7.38 (m, 10H, Sn-phenyl).31P NMR:
24.25 ppm.
[(H2O)(8-Q)n-Bu2Sn(l-1,5-C10H6(SO3)2)n-Bu2Sn(8-Q)(H2O)]
(6). A mixture of [n-Bu2SnO]n (0.24 g, 1.0 mmol) and 1,5-
napthalendisulfonic acid tetrahydrate (0.37 g 1.0 mmol) was taken
in a toluene–methanol mixture (16 ml 5 : 3) and stirred for 2 h at
room temperature. This was followed by the addition of base-
treated 8-HQ (8-hydroxyquinoline, 0.13 g, 1 mmol) and Et3N
(0.14 mL, 1 mmol), stirred for 2.5 h at room temperature) to
the reaction mixture. After 3 days of stirring at room temperature,
the contents were filtered and the filtrate was evaporated in vacuo
to afford a bright yellow colored solid. This was washed twice
with diethylether and dichloromethane. The residual solid was
found to be soluble in methanol. Yellow colored crystals of
6 were obtained from its solution in methanol–acetonitrile. In
addition, a cream colored solid was also found to be deposited [1H
NMR identified it as {Et3NH+}2{1,5-C10H6-(SO3 )2}]. Crystals
-
of 6 were separated manually from the mixture. Yield: 0.15 g
(30%, for isolated crystals). M.p.: 208 ◦C. Anal. Calcd. for
C44H58N2O10S2Sn2 (1078.16 g) (%): C 48.97, N 2.60, H 5.42;
Found: C 49.05, N 2.71, H 5.56. IR (KBr, cm-1): 3201 [br,
n(H2O)], 1206 [m, n(SO3) asym. str.], 1160 [s, n(SO3) asym.
str.], 1019 [s, n(SO3) sym. str.], 993 [s, n(SO3) ionic], 607 [m,
n(C–S)], 1579(w) 1500(s) 1465(s) [n(C C)/n(C N)], 1108 [m,
n(C–O(8HQ))], 465 [w, n(Sn–O(8HQ))]. 1H NMR (500 MHz,
(CDCl3): d = 6.97–8.42 (m, 8HQ-CH, napthyl-CH), 9.11 (d,
HQ-CH), 0.71–1.10 (t, 12H, Sn–CH3), 1.22–1.62 (m, 24H, Sn–
CH2CH2CH2). 119Sn NMR (500 MHz, (CD3OD): d = -218.4 ppm,
-216 ppm.
-
[{n-Bu2Sn(DPPOM)2(H2O)(1,5-C10H6(SO3)(SO3 )}]·H2O (4·
H2O). A mixture of [n-Bu2SnO]n (0.07 g, 0.30 mmol) and
naphthalenedisulfonic acid tetrahydrate (0.12 g 0.30 mmol) taken
in toluene–methanol (16 mL 5 : 3) was stirred for 45 min at
room temperature affording a white precipitate. Addition of two
equivalents of DPPOM (0.25 g, 0.60 mmoL) to the mixture
resulted in the formation of a clear solution for a few seconds,
followed by precipitation of a white solid. The reaction contents
were stirred further for 60 h. The solid obtained was filtered,
washed with 2 mL each of methanol, acetone and diethylether and
recrystallized from a methanol/acidified water mixture to obtain
block-like colorless crystals of 4·H2O. Yield: 0.24 g (61%). M.p.:
>250 ◦C. Anal. Calcd. for C68H72O12P4S2Sn (1387.95 g) (%): C
58.78, H 5.23; Found: C, 58.90, H, 5.31. IR (KBr, cm-1): 3431
[br, n(H2O)], 1185 1150 [s, (n(P O))], 1061 [m, n(SO3) sym. str.],
1021 [s, n(SO3) sym. str.], 988 [m, n(SO3) sym. str.], 609 [m, n(C–
S)], 3051(b,w) 2959 (m,b) 1464(w) 1436(m) 518(w) 503(m) 438(w)
413(w) [DPPOM]. 1H NMR (500 MHz, (CD3)2SO): d = 8.81
(d, 2H, naphthyl-CH), 7.89 (d, 2H, naphthyl-CH), 7.44 (t, 2H,
naphthyl-CH), 7.73 (b, DPPOM-aromaticCH), 7.38 (t, DPPOM-
aromaticCH), 4.14 (t, 4H, DPPOM-CH2), 0.83 (t, 6H, CH3), 1.24–
1.46 (m, 12H, Sn–CH2CH2CH2).
X-ray crystallographic study
The crystal data for compounds 1–6 were collected on a Bruker
SMART APEX CCD Diffractometer. SMART software package
(version 5.628) was used for collecting data frames, SAINT
software package (version 6.45) for integration of the intensity
and scaling and SADABS was used for absorption correction.
The details pertaining to the data collection and refinement for
crystals are provided in Tables S1–S3 of Supporting Information‡.
The structures were solved and refined by full-matrix least squares
on F2 using SHELXTL software package.16 Non-hydrogen atoms
were refined with anisotropic displacement parameters. Hydrogen
atoms were included in idealized positions, and a riding model was
used. All the hydrogens of the water molecules were located from
the difference map and refined isotropically. In the asymmetric unit
of 1, two of the four carbon atoms of one of the n-butyl groups
are disordered over two positions. These disordered positions
are labeled as C3 & C3A; C4 & C4A. The highest residual
electron density is 1.765 and is located near Sn1. Molecules of
2·2CH3OH contains crystallographic C2 symmetry, therefore the
atoms Sn1 and O3 have occupancies of 0.5. Besides, there is
an uncoordinated methanol molecule per asymmetric unit. The
asymmetric unit of 3·3H2O shows the presence of three lattice
water molecules (O12, O13, O14). In the asymmetric unit of
4·H2O, two of the carbons of one of the n-butyl chain were having
orientational disorder over three postions (C6, C6A & C6B and
C7, C7A & C7B). The two highest residual electron density of
1.70 and 1.46 are situated near this n-butyl chain because of the
presence of unresolved disorder associated with it. Molecules of
2+
-
[{Ph2Sn(DPPOM)2} {1,5-C10H6(SO3 )2}] (5). A mixture of
[Ph2SnO]n (0.09 g, 0.30 mmol) and 1,5-naphthalenedisulfonic
acid tetrahydrate (0.12 g 0.30 mmol) taken in toluene–methanol
(16 mL, 5 : 3) was stirred for 45 min at room temperature affording
a white precipitate. Addition of two equivalents of DPPOM
(0.25 g, 0.60 mmoL) to the mixture afforded a clear solution
which persisted for a few seconds, followed by precipitation of
a white solid. The reaction contents were stirred further for a
period of 50 h. The solid obtained was filtered, washed with 2 mL
each of methanol, acetone and diethylether and recrystallized from
methanol/acidified water to obtain 5. Yield: 0.26 g (60%). M.p.:
>270 ◦C. Anal. Calcd. for C72H60O10P4S2Sn (1392.16 g) (%): C
62.06, H 4.34; Found: C 61.99, H 4.46. IR (KBr, cm-1): 1187
1130 [s, (n(P O))], 1083 [s, n(SO3) sym. str.], 1030 [s, n(SO3)
sym. str.], 996 [m, n(SO3) sym. str.], 609 [m, n(C–S)], 3057(b,w)
2918 (m,b) 1485(w) 1439(m) 504(m) 477(w) 413(w) [DPPOM]. 1H
NMR (500 MHz, (CD3)2SO): d = 8.82 (d, 2H, naphthyl-CH),
7.88 (d, 2H, naphthyl-CH), 7.73–7.76 (b, aromatic-CH) 7.43–
122 | Dalton Trans., 2011, 40, 114–123
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5 contains crystallographic P2 symmetry, therefore the atom Sn1
has occupancy of 0.5. The asymmetric unit of 6 shows half portion
of the dimer, and comprises one tin atom, two n-butyl groups, one
molecule of 1,5-naphthalenedisulfonate ligand one 8-Q ligand,
and one coordinated water molecule. One of the carbon atoms of
one of the two n-butyl groups were found to have orientational
disorder [C4 & C4A (occupancy ratio 0.40 : 0.60)]. Figures (1–8)
and their bonding parameters were obtained from DIAMOND
3.1f software package.17
and J. Holecˇek, Organometallics, 2004, 23, 5300–5307; (f) K. Peveling,
M. Henn, C. Lo¨w, M. Mehring, C. B. Schu¨rmann and K. Jurkschat,
Organometallics, 2004, 23, 1501–1508.
4 B. Kasˇna´, R. Jambor, L. Dosta´l, L. Kola´rˇova´, I. C´ısarˇova´ and J.
Holecˇek, Organometallics, 2006, 25, 148–153.
5 (a) L. Hippel, P. G. Jones and A. Blaschette, J. Organomet. Chem.,
1993, 448, 63–67; (b) V. Chandrasekhar, R. Boomishankar, S. Singh,
A. Steiner and S. Zacchini, Organometallics, 2002, 21, 4575–4577;
(c) V. Chandrasekhar, R. Boomishankar, A. Steiner and J. F. Bickley,
Organometallics, 2003, 22, 3342–3344; (d) V. Chandrasekhar and P.
Singh, Organometallics, 2009, 28, 42–44; (e) V. Chandrasekhar and P.
Singh, Organometallics, 2009, 28, 4974–4978; (f) A. G. Davies, J. P.
Goddard, M. B. Hursthouse and N. P. C. Walker, J. Chem. Soc., Chem.
Commun., 1983, 597–598.
6 (a) R. S. Tobias, I. Ogrins and B. A. Nevett, Inorg. Chem., 1962, 1,
638–646; (b) R. S. Tobias, H. N. Farrer, M. B. Hughes and B. A.
Nevett, Inorg. Chem., 1966, 5, 2052–2055; (c) G. Arena, R. Purrello,
E. Rizzarelli, A. Gianguzza and L. Pellerito, J. Chem. Soc., Dalton
Trans., 1989, 773–777; (d) G. Arena, A. Gianguzza, S. Musuumec, L.
Pellerito, R. Purrello and E. Rizzarelli, J. Chem. Soc., Dalton Trans.,
1990, 2603–2608; (e) R. Barbieri and A. Silvestri, Inorg. Chim. Acta,
1991, 188, 95–98; (f) R. S. Tobias and M. Yasuda, Can. J. Chem., 1964,
42, 781–791.
Acknowledgements
We are thankful to the Department of Science and Technology
(DST), New Delhi, for financial support including support for
a CCD X-ray Diffractometer facility at IIT-Kanpur. PS thanks
Council of Scientific and Industrial Research, India for Senior
Research Fellowship. VC is thankful to the DST for a J. C. Bose
National fellowship.
7 (a) V. Chandrasekhar, K. Gopal and P. Thilagar, Acc. Chem. Res., 2007,
40, 420–434 and references there in; (b) V. Chandrasekhar, P. Singh,
K. Gopal in: Tin Chemistry: Fundamental, Frontiers and Applications,
A. G. Davies, M. Gielen, K. H. Pannell, E. R. T. Tiekink (Eds);
Wiley-VCH, Weinheim, 2008, pp. 93–114; (c) A. G. Davies Organotin
Chemistry WILEY-VCH, Verlag, GmbH and Co. KGaA, Weinheim,
2004; (d) V. Chandrasekhar, S. Nagendran and V. Baskar, Coord. Chem.
Rev., 2002, 235, 1–52; (e) J. Beckmann and K. Jurkschat, Coord. Chem.
Rev., 2001, 215, 267–300; (f) V. Chandrasekhar, P. Singh and K. Gopal,
Appl. Organomet. Chem., 2007, 21, 483–503.
8 (a) J. Beckmann, D. Dakternieks, A. Duthie and C. Mitchell,
Dalton Trans., 2003, 3258–3263; (b) V. Chandrasekhar and P. Singh,
Organometallics, 2007, 26, 2833–2839.
9 V. Chandrasekhar and P. Singh, Cryst. Growth Des., 2010, 10, 3077–
3093.
Notes and references
1 (a) E. G. Rochow, D. Seyferth and A. C. Smith Jr., J. Am. Chem.
Soc., 1953, 75, 3099–3101; (b) A. Blaschette, I. Hippel, K. Juergen,
E. Wieland, P. G. Jones and S. Angelika, J. Organomet. Chem., 1992,
437, 279–297; (c) A. Wirth, O. Moers, A. Blaschette and P. G. Jones,
Z. Anorg. Allg. Chem., 1999, 625, 982–988; (d) J. Beckmann, D.
Dakternieks, A. Duthie and C. Mitchell, Organometallics, 2003, 22,
2161–2164; (e) J. Beckmann, D. Dakternieks, A. Duthie and F. S.
Kuan, Organometallics, 2003, 22, 4399–4404; (f) M. Wada and R.
Okawara, J. Organomet. Chem., 1965, 4, 487–488; (g) A. G. Davies,
J. P. Goddard, M. B. Hursthouse and N. P. C. Walker, J. Chem. Soc.,
Dalton Trans., 1986, 1873–1877; (h) A. Blaschette, D. Schomburg and
E. Wieland, Z. Anorg. Allg. Chem., 1989, 571, 75–81; (i) J. Beckmann,
D. Dakternieks, A. Duthie and C. Mitchell, Organometallics, 2004, 23,
6150–6159; (j) M. Ichinohe, H. Fukui and A. Sekiguchi, Chem. Lett.,
2000, 600.
2 (a) K. Sakamoto, Y. Hamada, H. Akashi, A. Orita and J. Otera,
Organometallics, 1999, 18, 3555–3557; (b) S. Durand, K. Sakamoto,
T. Fukuyama, A. Orita, J. Otera, A. Duthie, D. Dakternieks, M.
Schulte and K. Jurkschat, Organometallics, 2000, 19, 3220–3223; (c) K.
Ohkubu, T. Suenobu, H. Imahori, A. Orita, J. Otera and S. Fukuzumi,
Chem. Lett., 2001, 978; (d) X. Li, A. Kurita, S. Man-e, A. Orita and
J. Otera, Organometallics, 2005, 24, 2567–2569; (e) V. Chandrasekhar,
R. Boomishankar, K. Gopal, P. Sasikumar, P. Singh, A. Steiner and
S. Zacchini, Eur. J. Inorg. Chem., 2006, 4129; (f) W. A. Nugent, R. J.
McKinney and R. L. Harlow, Organometallics, 1984, 3, 1315–1317;
(g) D. L. An, Z. Peng, A. Orita, A. Kurita, K. Ohkubo, S. Man-e, X.
Li, S. Fukuzumi and J. Otera, Chem.–Eur. J., 2006, 12, 1642–1647.
3 (a) B. Kasˇna´, L. Dosta´l, R. Jira´sko, I. C´ısarˇova´ and R. Jambor,
Organometallics, 2008, 27, 3743–3747; (b) B. Kasˇna´, L. Dosta´l, R.
Jira´sko, I. C´ısarˇova´ and R. Jambor, Organometallics, 2007, 26, 4080–
4082; (c) R. Jambor, I. C´ısarˇova´, A. Ru˚zˇicˇka and J. Holecˇek, Acta
Crystallogr., Sect. C: Cryst. Struct. Commun., 2001, 57, 373–374; (d) A.
Ru˚zˇicˇka, L. Dosta´l, R. Jambor, V. Buchta, J. Brus, I. C´ısarˇova´, M.
Holcˇapek and J. Holecˇek, Appl. Organomet. Chem., 2002, 16, 315–
322; (e) B. Kasˇna´, R. Jambor, L. Dosta´l, A. Ru˚zˇicˇka, I. C´ısarˇova´
10 K. Sakamoto, H. Ikeda, H. Akashi, T. Fukuyama, A. Orita and J.
Otera, Organometallics, 2000, 19, 3242–3248.
11 (a) C. Pettinari, F. Marchetti, A. Cingolani, P. Riccardo, A. Drozdov
and S. Troyanov, Inorg. Chim. Acta, 2001, 312, 125–132; (b) S. Dondi,
M. Nardelli, C. Pelizzi, G. Pelizzi and G. Predieri, J. Organomet. Chem.,
1986, 308, 195–206; (c) G. Pelizzi, P. Tarasconi, F. Vitali and C. Pelizzi,
Acta Crystallogr., Sect. C: Cryst. Struct. Commun., 1987, 43, 1505–
1509.
12 (a) I. Garcia-Santos, J. Sanmartin, A. M. Garcia-Diebe, M. Fondo
and E. Gomez, Inorg. Chim. Acta, 2010, 363, 193–198 and references
therein; (b) M. E. Mahmoud, S. S. Haggag, M. A. Rafea and T. M.
Absel-Fattah, Polyhedron, 2009, 28, 3407–3414; (c) M. Ghedini, M. L.
Deda, I. Aiello and A. A. Grisolia, Synth. Met., 2003, 138, 189–
192.
13 Vogel’s Text book of Practical Organic Chemistry, B. S. Furniss,
A. J. Hannaford, P. W. G. Smith, A. R. Tatchell 5th edition, ELBS
and Longman: London, 1989.
14 P. G. Simpson, A. Vinciguerra and J. V. Quagliano, Inorg. Chem., 1963,
2, 282–286.
15 W. E. Slinkard and D. W. Meek, J. Chem. Soc., Dalton Trans., 1973,
1024–1027.
16 G. M. Sheldrick, SHELXTL version 6.14, Bruker AXS Inc., Madison,
WI, 2003.
17 DIAMOND version 3.1f, Crystal Impact GbR, Bonn, Germany, 2004.
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The Royal Society of Chemistry 2011
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©