Synthesis and characterisation of thioether crown hydrazones, and palladium(II) and platinum(II) complexes of 6-(2,4-dinitrophenylhydrazono)-1,4,8,11-tetrathiacyclotetradecane

Article abstract of DOI:10.1039/a705996e

Reaction of the functionalised thioether crowns [14]aneS₄-6-one (1,4,8,11-tetrathiacyclotetradecan-6-one, L¹) and [10]aneS₃-9-one (1,4,7-trithiacyclodecan-9-one, L²) with 2,4-dinitrophenylhydrazine in a protic solvent under acidic catalysis afforded the corresponding hydrazones L³ and L⁴, respectively, in high yield. Reaction of [14]aneS₄-6-one with p-nitrophenylhydrazine under similar conditions affords the hydrazone L⁵. Reaction of L³ with [Pd(MeCN)₄][BF₄]₂ in MeCN yielded the complex [Pd(L³)][BF₄]₂, while reaction of this ligand with [Pt(EtCN)₄][CF₃SO₃]₂ in MeCN afforded [Pt(L³)][CF₃SO₃]₂. The single-crystal structures of L³-L⁵ and of [Pd(L³)][BF₄]₂ have been determined. In all cases, π-π stacking is observed, the free macrocycles crystallising as polymeric arrays of face-sharing hydrazone moieties. In [Pd(L³)]²⁺, π-π interactions alternate with face sharing between planar [PdS₄]²⁺ units constructing a one-dimensional polymeric array. The hydrazone function forces distortions of the respective macrocyclic rings and imparts chirality to the [Pd(L³)]²⁺ cation. The potential of these molecules as building blocks for macrocyclic liquid crystals and extended supramolecular arrays is discussed, as is the need to consider steric factors in rationalising the reactivity of keto-functionalised thioether crowns.

Full text of DOI:10.1039/a705996e

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Synthesis and characterisation of thioether crown hydrazones, and
palladium(II) and platinum(II) complexes of 6-(2,4-
dinitrophenylhydrazono)-1,4,8,11-tetrathiacyclotetradecane
Liam R. Sutton, Alexander J. Blake, Wan-Sheung Li and Martin Schröder*
Department of Chemistry, The University of Nottingham, University Park, Nottingham,
UK NG7 2RD
Reaction of the functionalised thioether crowns [14]aneS4-6-one (1,4,8,11-tetrathiacyclotetradecan-6-one, L1) and
[10]aneS3-9-one (1,4,7-trithiacyclodecan-9-one, L2) with 2,4-dinitrophenylhydrazine in a protic solvent under
acidic catalysis afforded the corresponding hydrazones L3 and L4, respectively, in high yield. Reaction of
[14]aneS4-6-one with p-nitrophenylhydrazine under similar conditions affords the hydrazone L5. Reaction of
L3 with [Pd(MeCN)4][BF4]2 in MeCN yielded the complex [Pd(L3)][BF4]2, while reaction of this ligand with
[Pt(EtCN)4][CF3SO3]2 in MeCN afforded [Pt(L3)][CF3SO3]2. The single-crystal structures of L3–L5 and of
[Pd(L3)][BF4]2 have been determined. In all cases, π–π stacking is observed, the free macrocycles crystallising as
polymeric arrays of face-sharing hydrazone moieties. In [Pd(L3)]2ϩ, π–π interactions alternate with face sharing
between planar [PdS4]2ϩ units constructing a one-dimensional polymeric array. The hydrazone function forces
distortions of the respective macrocyclic rings and imparts chirality to the [Pd(L3)]2ϩ cation. The potential of these
molecules as building blocks for macrocyclic liquid crystals and extended supramolecular arrays is discussed, as is
the need to consider steric factors in rationalising the reactivity of keto-functionalised thioether crowns.
Homoleptic sulfur-donor macrocycles bearing extended func-
tionality are still rare and have only recently been applied to the
synthesis of mesogenic materials, both as free macrocycles and
as binding agents for the late transition-metal ions.1 The com-
mon feature of such materials is that the macrocycle bears a
number of lengthy organic substituents which generate the
anisotropy necessary to induce liquid-crystalline behaviour.2
Since derivatisation of a thioether crown must necessarily occur
on the carbon backbone, work has been undertaken to build in
precursor functionality which can be used subsequently for
extended derivatisation. Macrocyclic thioether crowns have
now been synthesized with hydroxyl,3 methine,4 hydroxy-
methyl5 and ketone6 functionalities. Most examples of further
derivatisation have focused on hydroxyl derivatives.1,5,7 To date
our own work in this area has concentrated on esterification of
[14]- and [16]-aneS4-diols.1
Keto-functionalised thioether crowns, first synthesized
independently by Setzer and Kellogg and their co-workers,6a,b
have been treated with hydrazine by Kellogg and co-workers8 to
yield both inter- and intra-molecular azines, demonstrating that
these carbonyl groups readily undergo sterically innocuous
condensations. However, attempted Wittig and Grignard add-
itions to these ketones were unsuccessful, the reason proposed
being that they have a high tendency to enolise due to the sulfur
atoms situated β to the carbonyl group.8
The tetradentate thioether crown [14]aneS4 (1,4,8,11-tetra-
thiacyclotetradecane) co-ordinates to an extensive range of
metal atoms, most commonly as a platform for a square-planar
S4 donor set.9 The d8 palladium() cation usually adopts
square-planar co-ordination and this is observed in its com-
plexes with both the parent ligand10 and with several function-
alised derivatives11 where the hydrocarbon links form the sides
of a shallow bowl with the PdS4 square as its base. We report
herein the synthesis of phenylhydrazono derivatives of [14]-
aneS4-6-one (1,4,8,11-tetrathiacyclotetradecan-6-one, L1) and
[10]aneS3-9-one (1,4,7-trithiacyclodecan-9-one, L2) and com-
plexes with PdII and PtII.
starting material via condensation with aryl-substituted hydra-
zines to generate resonance-stabilised functionalised macro-
cycles incorporating an sp2-hybridised carbon atom. Inter-
dependence of the conformation of each macrocycle and
the nature of its substituent is evident by comparison of the
single-crystal structures of the parent ketones, L1 and L2, their
hydrazones L3–L5, and [Pd(L3)]2ϩ
.
Synthesis of L1 and L2
The ketones used for further derivatisation, L1 and L2, were
prepared by literature methods developed primarily by Kellogg
and co-workers6a and by Setzer et al.6b Crystal structure deter-
minations6c,12 reveal that L1 and L2 adopt exodentate conform-
ations similar to those exhibited by their unsubstituted parent
macrocycles with little distortion due to the presence of the
carbonyl oxygen.
Synthesis and structural description of L3–L5
Compounds L3 and L4 were synthesized by the condensation13
of 2,4-dinitrophenylhydrazine with L1 and L2 respectively
(Scheme 1). The hydrazine was suspended in EtOH, then pro-
tonated by the careful addition of concentrated H2SO4, to yield
a bright yellow solution. This was then added to a colourless
solution of the ketone in boiling EtOH, generating instant
orange cloudiness in the mixture. Cooling to room temperature
afforded almost quantitative yields of hydrazone. Analogously,
L5 was synthesized from L1 and p-nitrophenylhydrazine using
glacial acetic acid to dissolve the hydrazine in EtOH. Crystal-
lisation at Ϫ18 ЊC yielded a mixture of product and excess of
hydrazinium salt. Recrystallisation from EtOH afforded a 63%
yield of yellow hydrazone L5.
Selected bond lengths and angles are listed in Table 1.
Features of note are the hydrogen bonds in compounds L3
and L4 between the hydrazone protons and an oxygen atom of
the nitro groups in the ortho positions of the phenyl groups.
Furthermore, the solid-state conformations of the macrocyclic
core change significantly on condensation with the hydrazones.
The crystal structure of L3 [Fig. 1(a)] reveals a marked distor-
tion of the macrocycle by comparison with the structure of
L1, which displays a quite regular [3434] conformation.6a The
Results and Discussion
The ligands were synthesized from the appropriate ketonic
J. Chem. Soc., Dalton Trans., 1998, Pages 279–284
279

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S
S
S
S
S
O
S
O
S
L1
L2
Hot EtOH/Acid H2NNH
NO2
R
S
S
N
HN
S
S
NO2
R
L3: R = NO2
L5: R = H
S
S
S
N
HN
NO2
R
L4: R = NO2
Fig. 2 Packing of compound L3. Hydrogen atoms omitted for clarity
Scheme 1 Synthesis of hydrazones
Fig. 3 Structure of compound L4
Fig. 1 Structures of compounds L3 (a) and L5 (b)
irregular [2435] conformation adopted by the macrocycle in L3
is, we propose, the result of a minimisation of steric interaction
between the hydrazone proton H(16) and S(1) (Table 2). The
packing diagram (Fig. 2) illustrates the π–π stacking in the
structure.15 Interplanar separations are 3.383 and 3.407 Å (cf.
3.354 Å in graphite),16 offset such that the centroid–centroid
separations between phenyl rings are both 3.905 Å (Table 3).
Fig. 3 shows the structure of a single molecule of compound
L4. The hydrazone proton again induces a solid-state conform-
ational change in the macrocycle relative to its parent ketone
which has a [2323] conformation.12 Significantly, the structure
of L4 shows 8 out of 10 torsion angles less than 90Њ (Table 2)
thus reducing direct contact between H(12) and S(1) and reflect-
ing severe distortions within the ring. Interaction between the
π systems of the molecules allows them to stack as arrays of
interlocking L shapes (Fig. 4), with interplanar distances of
3.270 and 3.359 Å.
Fig. 4 Packing of compound L4. Hydrogen atoms omitted for clarity
A similar disruption of the ring conformation occurs in
compound L5, which shows a [23225] conformation [Fig. 1(b)],
showing that the NH ؒ ؒ ؒ O2N hydrogen bond present in L3 and
L4 is not the key factor in determining the conformation of
the macrocycle. Rather, conjugation in the hydrazone forces
the NH hydrogen to occupy the position occupied by S(1) in
the ketonic macrocycles. By comparison, the structure of an
azine-bridged (᎐N᎐N᎐) dimer of [13]aneS O (1,4-dioxa-7,11-
᎐
᎐
2
2
dithiacyclotridecane) obtained by Kellogg and co-workers8
displays little distortion of the rings from the expected structure
of [13]aneS2O2-6-one, highlighting the importance of the
hydrazone proton. The π–π stacking motif observed in L4
is repeated in L5, with interplanar separations of 3.360 and
3.507 Å.
280
J. Chem. Soc., Dalton Trans., 1998, Pages 279–284

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Table 1 Selected bond lengths (Å) and angles (Њ)
Table 2 Diagnostic torsion angles for compounds L1–L5
S᎐C᎐C᎐X Anglesa/Њ
L3
Compound
L1
L3
L5
L2
L4
Ϫ11.2(3)b
Ϫ73.7(6)
Ϫ50.7(7)
Ϫ20.7, Ϫ19.5c
Ϫ46.6(8)
L3
Ϫ5.8(3)b
C(13)᎐N(15)
N(15)᎐N(16)
1.289(6)
1.380(6)
N(16)᎐C(17)
O(22A) ؒ ؒ ؒ H(16)
1.347(7)
1.98
Ϫ104.5(5)
133.7(4)
137.9, 136.2c
123.1(5)
L5
C(12)᎐C(13)᎐C(14)
118.4(5)
C(17)᎐N(16)᎐N(15) 120.0(4)
N(16)᎐C(17)᎐C(18) 120.3(5)
N(16)᎐C(17)᎐C(22) 123.6(5)
N(15)᎐C(13)᎐C(12) 115.6(3)
N(15)᎐C(13)᎐C(14) 126.0(5)
C(13)᎐N(15)᎐N(16) 116.3(4)
S(1)᎐C(2)᎐C(3)᎐S(4)
C(2)᎐C(3)᎐S(4)᎐C(5)
C(3)᎐S(4)᎐C(5)᎐C(6)
S(4)᎐C(5)᎐C(6)᎐C(7)
C(5)᎐C(6)᎐C(7)᎐S(8)
C(6)᎐C(7)᎐S(8)᎐C(9)
C(7)᎐S(8)᎐C(9)᎐C(10)
S(8)᎐C(9)᎐C(10)᎐S(11)
C(9)᎐C(10)᎐S(11)᎐C(12)
C(10)᎐S(11)᎐C(12)᎐C(13)
S(11)᎐C(12)᎐C(13)᎐C(14)
C(12)᎐C(13)᎐C(14)᎐S(1)
C(13)᎐C(14)᎐S(1)᎐C(2)
C(14)᎐S(1)᎐C(2)᎐C(3)
160.9(3)
176.0(4)
70.4(5)
69.0(6)
Ϫ164.2(4)
77.3(4)
Ϫ167.3(3)
Ϫ85.5(5)
74.7(5)
50.7(6)
172.4(4)
65.1(5)
L4
C(9)᎐N(11)
N(11)᎐N(12)
1.266(7)
1.392(5)
N(12)᎐C(13)
O(18A) ؒ ؒ ؒ H(12)
1.351(7)
2.01
72.8(5)
72.6(5)
C(8)᎐C(9)᎐C(10)
N(11)᎐C(9)᎐C(8)
N(11)᎐C(9)᎐C(10)
C(9)᎐N(11)᎐N(12)
115.1(5)
114.2(5)
130.3(5)
119.3(5)
C(13)᎐N(12)᎐N(11) 117.8(5)
N(12)᎐C(13)᎐C(14) 120.0(5)
N(12)᎐C(13)᎐C(18) 124.6(6)
Ϫ179.4(3)
102.7(4)
Ϫ140.4(4)
75.7(5)
106.2(5)
Ϫ64.1(4)
Ϫ73.4(4)
L4
Ϫ174(3)
170.4(4)
Ϫ79.8(5)
Ϫ53.8(6)
137.9(4)
Ϫ45.3(5)
Ϫ178.7(4)
L5
C(13)᎐N(15)
N(15)᎐N(16)
1.298(7)
1.375(6)
N(16)᎐C(17)
1.382(7)
S(1)᎐C(2)᎐C(3)᎐S(4)
C(2)᎐C(3)᎐S(4)᎐C(5)
C(3)᎐S(4)᎐C(5)᎐C(6)
S(4)᎐C(5)᎐C(6)᎐S(7)
C(5)᎐C(6)᎐S(7)᎐C(8)
C(6)᎐S(7)᎐C(8)᎐C(9)
S(7)᎐C(8)᎐C(9)᎐C(10)
C(8)᎐C(9)᎐C(10)᎐S(1)
C(9)᎐C(10)᎐S(1)᎐C(2)
C(10)᎐S(1)᎐C(2)᎐C(3)
158.6(3)
Ϫ66.1(5)
Ϫ83.5(5)
67.3(6)
C(14)᎐C(13)᎐C(12)
117.8(4)
N(15)᎐N(16)᎐C(17) 118.4(5)
N(16)᎐C(17)᎐C(18) 121.8(5)
N(16)᎐C(17)᎐C(22) 118.3(5)
N(15)᎐C(13)᎐C(12) 114.1(5)
N(15)᎐C(13)᎐C(14) 127.6(5)
C(13)᎐N(15)᎐N(16) 117.2(4)
72.6(6)
Ϫ82.2(5)
Ϫ63.9(6)
141.7(4)
Ϫ42.1(5)
Ϫ63.5(5)
[Pd(L3)][BF4]2ؒ1.5MeCN
Pd᎐S(1)
Pd᎐S(4)
Pd᎐S(8)
Pd᎐S(11)
2.295(4)
2.301(3)
2.294(4)
2.308(4)
C(13)᎐N(15)
N(15)᎐N(16)
N(16)᎐C(17)
O(22A) ؒ ؒ ؒ H(16)
1.29(2)
1.27(2)
1.41(3)
1.96
a X = O or N. b Ref. 6(c). c Taken from the Cambridge Structural Data-
base.12,14
S(1)᎐Pd᎐S(4)
S(8)᎐Pd᎐S(4)
S(8)᎐Pd᎐S(11)
S(1)᎐Pd᎐S(11)
C(14)᎐C(13)᎐C(12)
87.9(2)
87.7(2)
87.8(2)
96.6(2)
120.8(13)
N(15)᎐C(13)᎐C(12) 116.7(14)
N(15)᎐C(13)᎐C(14) 123(2)
N(15)᎐N(16)᎐C(17) 119(2)
C(18)᎐C(17)᎐N(16) 119(2)
C(22)᎐C(17)᎐N(16) 122(2)
Table 3 Phenyl ring separations in compounds L3–L5 and [Pd(L3)]-
[BF4]2ؒ1.5MeCN
Centroid–centroid
distancea/Å
Interplanar
separationb/Å
L3
3.905, 3.905
3.602, 3.700
4.262, 4.519
3.683, —
3.383, 3.407
3.270, 3.359
3.360, 3.507
3.270, —
L4
L5
[Pd(L3)]2ϩ
a Distance between dummy atoms placed at geometric centroids of
adjacent phenyl ring carbon atoms. b Perpendicular distance from
dummy atom to mean plane of adjacent phenyl ring carbon atoms.
Fig. 5 Packing of compound L5. Hydrogen atoms omitted for clarity
In the stacking of compounds L3–L5, large lateral offsets of
neighbouring phenyl rings occur. This is due in part to the
extended π systems of the phenyl ring, nitro groups and the
hydrazone function. The view of the packing in L5 in Fig. 5,
perpendicular to the aromatic plane, shows the close aligning of
phenyl rings in adjacent hydrazones.
Fig. 6 Structure of the cation in [Pd(L3)][BF4]2ؒ1.5MeCN. Minor
parts of disorder and most hydrogens omitted for clarity
cation is shown in Fig. 6. Disorder modelling of the cation,
both anions and both solvate molecules was required to refine
the structure, an important factor in the cation being rotation
of 180Њ about the C(13)᎐N(15) bond. The minor parts of the
disorder are omitted for clarity. The Pd᎐S distances are similar
to those in [Pd([14]aneS4)][PF6]2,10 with the sp2 hybridisation of
C(13) leading to an increase in the S(11)᎐Pd᎐S(1) angle to
96.6(2)Њ but with the other three angles lying in the narrow
range 87.7(2)–87.9(2)Њ.
Synthesis of complexes of PdII and PtII
The complex [Pd(L3)][BF4]2 was synthesized by the addition
of a solution of [Pd(MeCN)4][BF4]2 in MeCN to an orange
mixture of MeCN and the partially soluble L3. The mixture
immediately cleared and darkened slightly, the yellow product
being crystallised by layering with Et2O.
Crystals of composition [Pd(L3)][BF4]2ؒ1.5MeCN were
analysed by X-ray crystallography and the structure of the
J. Chem. Soc., Dalton Trans., 1998, Pages 279–284
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Fig. 7 Linear polymeric array of cations in [Pd(L3)][BF4]2ؒ1.5MeCN. Minor parts of disorder omitted for clarity. Phenyl centroid separation
(– – – –) = 3.683 Å; S(4) ؒ ؒ ؒ S(4) 3.341 Å
functionalised thioether crowns. The marked distortion of the
macrocycles due to a remote hydrogen atom implies that the
steric interaction between the ring and the added substituent
is critical. In our hands, attempted acid-catalysed imine form-
ation using anilines in benzene under azeotropic distillation
conditions resulted in C᎐S bond cleavage and decomposition,
presumably via β-proton elimination.17a Comba et al.17b have
recently investigated thermal C᎐S bond cleavage and ring con-
traction in 6-chloro- and 6,13-dichloro-[14]aneS4. We speculate
that the thioether crown hydrazones exhibit intermediate stabil-
ity compared with crown thioethers bearing small substituents
like oxygen and CH2 and hypothetical examples bearing steri-
cally demanding aromatic imines. The forcing conditions
required to synthesize the imines thus cause decomposition. We
also conclude that the failure of certain functionalisations of
thioether crown ketones has a steric basis.
We are currently attempting to extend the chains attached to
the macrocycles using both covalent and non-covalent bonding
so increasing the anisotropy of the products. Of particular
interest is the nitro–iodo interaction between nitro- and iodo-
benzenes recently reviewed by Desiraju.18 These approaches
should in due course lead to both thermotropic and lyotropic
liquid crystals and extended arrays.
Ϫ
Fig.
8
Influence of BF4 on cation packing in [Pd(L3)][BF4]2ؒ
1.5MeCN
Compound L3 co-ordinates to PdII to produce a flattened
cup-like structure, resulting in chirality since the hydrazone at
the rim of the cup can point either clockwise or anticlockwise,
generating distinct enantiomers. The sp2 linkage is rigid and
the macrocycle is denied flexibility by the co-ordinated metal
atom. In constructing linear polymers of cations (Fig. 7), the
dicationic heads are held in close proximity with a shortest
contact between neighbouring S(4) atoms of 3.341 Å. The
tetrafluoroborate anions appear to exert considerable influence
on the arrangement of the cations, with F atoms in close prox-
imity to Pd, S(8) and S(11) and certain H atoms (Fig. 8). The
aromatic groups show an interplanar separation of 3.270 Å.
The linear polymers, formed from predominantly identical
enantiomers, lie side by side to form sheets, with alternate
sheets constructed from the alternate enantiomer to produce a
racemic crystal.
Experimental
Spectra were recorded on a Bruker DPX 300 (1H and 13C
NMR) and a Perkin-Elmer 1600 spectrometer (FTIR, samples
in KBr discs). Melting points were measured using
a
Gallenkamp apparatus and are uncorrected. Elemental
analytical data were obtained by the Microanalytical Service
(Perkin-Elmer 240B analyser) at the University of Nottingham
and EI (electron impact) mass spectra were measured using a
VG Autospec VG7070E spectrometer. Electrospray mass
spectra were obtained by the EPSRC National Mass Spec-
trometry Service at the University of Swansea. The compounds
[14]aneS4-6-one (L1), [10]aneS3-9-one (L2), [Pd(MeCN)4][BF4]2
and [Pt(EtCN)4][CF3SO3]2 were prepared according to liter-
ature methods.6,19 All starting materials, including anhydrous
dimethylformamide, were obtained from Aldrich or Lancaster
Synthesis and used without further purification.
The complex [Pt(L3)][CF3SO3]2 was synthesized using a
similar method to that for [Pd(L3)][BF4]2 but using [Pt(EtCN)4]-
[CF3SO3]2 as starting material. The yellow suspension of L3 in
MeCN cleared only slightly on addition of the [Pt(EtCN)4]-
[CF3SO3]2 but no colour change was observed in this case. The
cloudiness is presumably due to some hydrolysed platinum()
starting material, which is relatively moisture-sensitive. The
reaction mixture was filtered and the filtrate evaporated, then
taken up in a small amount of MeCN and precipitated by layer-
ing with Et2O. Satisfactory characterisation data were obtained
for all compounds using NMR, IR and mass spectrometry and
elemental analysis.
Syntheses
1,4,8,11-Tetrathiacyclotetradecane-6-one 2,4-dinitrophenyl-
hydrazone (L3) and 1,4,7-trithiacyclodecane-9-one 2,4-dinitro-
phenylhydrazone (L4). 2,4-Dinitrophenylhydrazine (50 mg, 0.25
mmol) was suspended in EtOH (5 cm3) in an Erlenmeyer flask
(25 cm3). To the stirred solution were added five drops of
concentrated H2SO4 yielding a yellow solution. In another
Erlenmeyer flask (25 cm3) compound L1 (42 mg, 0.15 mmol) or
L2 (31 mg, 0.15 mmol) was dissolved in boiling EtOH (5 cm3)
and stirred; the hydrazine solution was added to this colourless
solution giving an orange suspension which on cooling to 4 ЊC
yielded a yellow microcrystalline solid and an orange super-
Conclusion
Thioether crown ketones may be condensed with nitrophenyl-
hydrazines to give new amphiphilic ligands for late transition
metals. These ligands may be used in complex-forming reac-
tions with PdII and PtII. The crystal structures highlight exten-
sive π–π interaction while in the new palladium() complex
sheets of parallel chains of chiral amphiphiles are formed.
Furthermore, the crystal structures suggest an additional
explanation for the failure of many reactions involving keto-
282
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Table 4 Crystallographic data summarya
L3
L4
L5
[Pd(L3)][BF4]2ؒ1.5MeCN
Empirical formula
M
C16H22N4O4S4
462.62
C13H16N4O4S3
388.48
C16H23N3O2S4
417.6
C19H26.5B2F8N5.5O4PdS4
804.22
Colour, habit
Crystal size/mm
Crystal system
Space group
Yellow plate
0.65 × 0.37 × 0.04
Monoclinic
P21/c
Yellow needle
0.35 × 0.10 × 0.06
Monoclinic
P21/c
Yellow plate
0.47 × 0.22 × 0.12
Triclinic
Yellow column
0.33 × 0.20 × 0.19
Triclinic
¯
¯
P1
P1
a/Å
b/Å
c/Å
α/Њ
7.7711(19)
19.458(9)
13.480(4)
—
93.63(3)
—
2034.3(10)
4
1.511
7.249(4)
10.786(4)
21.330(9)
—
96.66(4)
—
1656.5(10)
4
1.558
5.6363(11)
8.7733(15)
19.833(4)
93.28(2)
93.55(2)
105.54(2)
940.3(3)
2
10.181(2)
12.569(3)
13.985(3)
96.16(2)
107.81(2)
96.02(2)
1676.1(4)
2
β/Њ
γ/Њ
U/Å3
Z
Dc/g cmϪ3
1.475
1.594
T/K
150
0.498
150
0.474
150
0.521
210
0.881
µ/mmϪ1
F(000)
2θ Range/Њ
968
5–50
808
5–45
440
5–45
806
5–45
Independent reflections
Observed reflections [|Fo| > 4σ(|Fo|)]
Absorption correction method
Maximum, minimum transmission
Decay correction (%)
Number of parameters
Weighting scheme a, bb
Final R1 (wR2)c
Maximum ∆/σ
4402
2463
ψ Scans
0.880, 0.803
Random
253
0, 6.41
0.0688 (0.1171)
0.001
2148
1265
None
—
Random 8.5
218
0.22, 0
0.0556 (0.1213)
0.001
0.30, Ϫ0.31
2462
1866
None
—
10
227
0.064, 2.54
0.0557 (0.0842)
<0.001
0.34, Ϫ0.52
4402
3257
Numerical
0.898, 0.838
38.6
2
381
0.13, 39.0
0.1071 (0.1439)
0.009
Largest difference peak, hole/e ÅϪ3
0.38, Ϫ0.40
1.68, Ϫ1.83
a Details in common: Stoë Stadi-4 four-circle diffractometer, Oxford Cryosystems open-flow cryostat,21 graphite-monochromated Mo-Kα radiation
2
(λ = 0.710 73 Å); ω–θ scans; refinement based on F 2. b In wϪ1 = σ2(Fo ) ϩ (aP)2 ϩ bP, where P = (Fo2 ϩ 2Fc2)/3. c Defined in ref. 20.
natant. The solid was separated by suction filtration, washed
with cold EtOH (2 × 5 cm3) and dried in vacuo. Crystals of
L3 suitable for X-ray diffraction were grown by diffusion of
Et2O vapour into a CH2Cl2 solution at 4 ЊC. Compound L4 was
crystallised by slow evaporation of a CH2Cl2 solution at room
temperature.
(5 cm3) and treated with glacial acetic acid (four drops). On
heating, a dark brown solution formed which was mixed with
the refluxing ketone solution. The mixture was refluxed for 1 h,
then stoppered and stored at Ϫ18 ЊC for 18 h. The resulting
precipitate was isolated by suction filtration and recrystallised
from EtOH to yield a yellow powder. Crystals suitable for X-ray
diffraction were grown by slow evaporation of a solution of L5
in CHCl3.
Compound L3: yield 64 mg (93%) (Found: C, 41.9; H, 4.8; N,
11.7. C16H22N4O4S4 requires C, 41.5; H, 4.8; N, 12.1%); m.p.
130 ЊC (decomp.); ν max/cmϪ1 3311m, 1615vs, 1590s, and 1510s;
δH(CDCl3) 9.16 [1 H, s, C(NO2)CHC(NO2)], 8.35 (1 H, m, aryl),
7.97 (1 H, m, aryl), 3.75 (2 H, s, Z-CH C᎐NNH), 3.63 (2 H, s,
Compound L5: yield 47 mg, 0.11 mmol (63%) (Found: C,
46.1; H, 5.7; N, 10.3. C16H23N3O2S4 requires C, 46.0; H, 5.6; N,
10.1%); m.p. 141–143 ЊC (decomp.); ν max/cmϪ1 3273m, 2920m,
1595vs, 1523s, 1498s, 1481s, 1425w, 1324vs, 1264vs, 1110vs and
1080s; δH(CDCl3) 9.37 (1 H, s, NH), 8.18 (2 H, m) and 7.10 (2
᎐
2
E-CH C᎐NNH), 3.05–2.90 (8 H, m, SCH CH S), 2.75 (4 H, m,
᎐
2
2
2
CH2CH2CH2) and 1.95 (2 H, qnt, CH2CH2CH2); δC[CDCl3, H
connectivity confirmed by DEPT (distortionless enhance-
H, m, aryl), 3.69 (2 H, s) and 3.50 (2 H, s, CH C᎐N), 2.98–2.86
᎐
2
ment of polarisation transfer) 90 and DEPT 135] 151.72 (C᎐N),
(8 H, m, SCH2CH2S), 2.75–2.67 (4 H, m, CH2CH2CH2) and
᎐
144.80, 138.71 and 130.24 (aryl CN), 129.95, 123.30 and 116.63
1.90 (2 H, m, CH CH CH ); δ (CDCl ) 149.64 (C᎐N), 142.83
᎐
2 2 2 C 3
(aryl CH), 39.79 (Z-CH C᎐NNH) and 33.86, 33.65, 32.59,
and 140.68 (aryl CN), 125.99 and 112.11 (aryl CH), 40.39,
33.32, 32.69, 32.38, 32.06, 30.72, 30.38, 29.64 and 29.40 (CH2);
m/z (EI) 417 (Mϩ).
᎐
2
32.24, 31.03, 30.70, 29.93 and 29.27 (other CH2); m/z (EI) 460
(Mϩ Ϫ 2 H) and 391 (Mϩ Ϫ 71).
Compound L4: yield 50 mg (87%) (Found: C, 39.7; H, 4.3; N,
14.0. C13H16N4O4S3 requires C, 40.2; H, 4.15; N, 14.4%); m.p.
168 ЊC (decomp.); ν max/cmϪ1 3157m, 3087w, 2914w, 2852w,
1613vs, 1590s, 1530m, 1513s and 1499s; δH(CDCl3) 9.15 [1 H, s,
C(NO2)CHC(NO2)], 8.33 (1 H, m, aryl), 7.95 (1H, m, aryl), 3.75
[Pd(L3)][BF4]2. A Schlenk tube (50 cm3) was charged with
compound L3 (20 mg, 0.04 mmol) and a magnetic stirrer bar
and pump-filled with N2. A solution of [Pd(MeCN)4][BF4]2 (19
mg, 0.04 mmol) in degassed MeCN (10 cm3) was added via
cannula, which was washed through with degassed MeCN (5
cm3). The yellow solution became orange as all of the hydra-
zone dissolved. The solution was stirred for 1 h but no further
change was observed. The MeCN solution was then layered
with diethyl ether (30 cm3) and left to stand for 24 h. Orange
crystals formed which immediately became powder on suction
filtration.
(2 H, s, Z-CH C᎐NNH), 3.50 (2 H, s, E-CH C᎐NNH) and
᎐
᎐
2
2
3.24–2.83 (8 H, m, SCH2CH2S); δC(CDCl3, H connectivity con-
firmed by DEPT 90 and DEPT 135) 151.38 (C᎐N), 144.86,
᎐
138.59 and 130.42 (aryl CN), 129.77, 123.34 and 116.55 (aryl
CH), 41.68, 35.12, 35.00, 34.16, 33.43 and 31.02 (CH2); m/z (EI)
327 (Mϩ Ϫ 71).
1,4,8,11-Tetrathiacyclotetradecane-6-one 4-nitrophenylhydra-
zone (L5). In a round-bottomed flask (25 cm3) equipped with a
magnetic stirrer bar and a reflux condenser, compound L1 (50
mg, 0.18 mmol) was suspended in EtOH (5 cm3) and refluxed to
give a colourless solution. In a second flask (25 cm3), p-nitro-
phenylhydrazine (50 mg, 0.33 mmol) was suspended in EtOH
[Pd(L3)][BF4]2ؒ0.5MeCN: yield 28 mg, 0.038 mmol (94%)
(Found: C, 26.5; H, 3.3; N, 7.9. C16H22B2F8N4O4PdS4ؒ
0.5MeCN requires C, 26.8; H, 3.1; N, 8.25%); ν max/cmϪ1 3432m,
2923w, 2211vs, 1615s, 1596s, 1503m, 1427w, 1340s and 1084s;
δH(CD3CN) 11.12 (1 H, s, NH), 8.99 (1 H, m, CNCHCN), 8.44
(1 H, m) and 7.95 (1 H, m, CNCHCHCN), 4.43–4.37 (4 H, m,
J. Chem. Soc., Dalton Trans., 1998, Pages 279–284
283

View Article Online
CH C᎐N) and 3.93–2.90 (16 H, m, other SCH ) (CH CH CH
2
᎐
Acknowledgements
2
2
2
2
coincident with solvent peaks at 2.20–1.90); δC(CD3CN)
144.99, 141.33 and 132.78 (aryl CN), 131.35, 123.74 and 118.20
(aryl CH), 43.26, 42.61, 42.35, 39.18, 38.78, 36.14 (2 C), 32.25,
26.26 (CH2) (CH at 118.20 coincident with CD3CN, detected
We thank the EPSRC for support and the EPSRC National
Mass Spectrometry Service at the University of Swansea
for electrospray mass spectra. We also thank Professors R. M.
Kellogg and P. Comba for details of unpublished results.
using DEPT 90 and 135; C᎐N not detected but possibly coinci-
᎐
dent with one of the aryl CN peaks; H connectivity confirmed
using DEPT); m/z (positive-ion electrospray, MeOH, 80 V) 567
(Mϩ Ϫ 2 BF4, 100%).
Crystals suitable for X-ray analysis were grown by diffusion
of Et2O vapour into an MeCN solution of the complex. They
were found to be of composition [Pd(L3)][BF4]2ؒ1.5MeCN.
References
1 A. J. Blake, D. W. Bruce, I. A. Fallis, S. Parsons and M. Schröder,
J. Chem. Soc., Chem. Commun., 1994, 2471; A. J. Blake, D. W. Bruce,
I. A. Fallis, S. Parsons, H. Richtzenhain, S. A. Ross and
M. Schröder, Philos. Trans. R. Soc. London, Ser. A, 1996, 354, 395.
2 F. Vögtle in Supramolecular Chemistry, Wiley, Chichester, 1991,
pp. 231–290.
3 V. B. Pett, G. H. Leggett, T. H. Cooper, P. R. Reed, D. Situmeang,
L. A. Ochrymowycz and D. B. Rorabacher, Inorg. Chem., 1988, 27,
2164; M. Tomoi, O. Abe, N. Takazu and H. Kakiuchi, Makromol.
Chem., 1983, 184, 2431.
4 J. Buter, R. M. Kellogg and F. van Bolhuis, J. Chem. Soc., Chem.
Commun., 1990, 282.
5 R. J. Smith, S. N. Salek, M. J. Went, P. J. Blower and N. J. Barnard,
J. Chem. Soc., Dalton Trans., 1994, 21, 3165; R. J. Smith, G. D.
Admans, A. P. Richardson, H. J. Kuppers and P. J. Blower, J. Chem.
Soc., Chem. Commun., 1991, 475.
6 (a) J. Buter, R. M. Kellogg and F. van Bolhuis, J. Chem. Soc., Chem.
Commun., 1991, 910; (b) W. N. Setzer, S. Afshar, N. L. Burns, L. A.
Ferrante, A. M. Hester, E. J. Meehan, jun., G. J. Grant, S. M. Isaac,
C. P. Laudeman, C. M. Lewis and D. G. VanDerveer, Heteroat.
Chem., 1990, 1, 375; (c) L. R. Sutton, A. J. Blake, W.-S. Li and
M. Schröder, Acta Crystallogr., Sect. C, in the press.
7 K. Saito, I. Taninaka, S. Murakami and A. Muromatsu, Anal.
Chim. Acta, 1994, 299, 137; K. Yamashita, K. Kurita, K. Ohara,
K. Tamura, M. Nango and K. Tsuda, React. Funct. Polym., 1996,
31, 47; G. De Santis, L. Fabbrizzi, M. Licchelli, C. Mangano and
D. Sacchi, Inorg. Chem., 1995, 34, 3581; G. De Santis, L. Fabbrizzi,
M. Licchelli, C. Mangano, D. Sacchi and N. Sardone, Inorg. Chim.
Acta, 1997, 257, 69.
[Pt(L3)][CF3SO3]2. To a stirred suspension of L3 (11 mg,
0.024 mmol) in MeCN (5 cm3) in a round-bottomed flask (25
cm3) was added a solution of [Pt(EtCN)4][CF3SO3]2 (17 mg,
0.024 mmol) in MeCN (5 cm3). The flask was stoppered and the
mixture stirred for 24 h at room temperature. After this time
a faintly cloudy yellow solution had formed which was fil-
tered by gravity. The filtrate was evaporated, the residue taken
up in MeCN (2 cm3) and precipitated by layering with Et2O
and storing at 4 ЊC for 16 h. A yellow powder was isolated by
suction filtration, washed with Et2O (2 × 5 cm3) and dried
in air.
[Pt(L3)][CF3SO3]2: yield 17 mg, 0.018 mmol (75%) (Found: C,
25.3; H, 2.9; N, 6.0; Pt, 19.0. C18H22F6N4O10PtS6ؒEt2O requires
C, 25.7; H, 3.1; N, 5.4; Pt, 18.9%); m.p. 155–160 ЊC (decomp.);
ν max/cmϪ1 3454m, 3295w, 2983w, 2926w, 1519s, 1596m, 1502s,
1421w, 1343vs, 1316m, 1261vs, 1165s, 1097w, 1030s, 638s and
518w; δH(CD3CN) 11.16 (1 H, s, NH), 9.00, 8.44, 7.97 (each 1
H, m, aryl), 4.63–4.40 (3 H, m), 3.96–2.85 (m, 13 H, SCH2) and
2.12 (H2O, conceals CH2CH2CH2); δC(CD3CN) 144.99, 141.39,
140.53, 132.60 (C᎐N and aryl CN), 131.40, 123.80, 120.01 (aryl
᎐
CH), 43.42, 43.17, 42.27, 41.23, 38.95, 38.47, 36.61, 32.75, 26.12
(other CH); m/z (positive-ion electrospray, MeCN) 958
(Mϩ ϩ 2 H) and 657 (Mϩ Ϫ 2 CF3SO3Ϫ Ϫ H) (both peak sets
agree closely with theoretical distributions).
8 J. J. H. Edema, J. Buter, R. M. Kellogg, A. L. Spek and F. van
Bolhuis, J. Chem. Soc., Chem. Commun., 1992, 1558.
9 A. J. Blake and M. Schröder, Adv. Inorg. Chem., 1990, 35, 1;
S. R. Cooper, Struct. Bonding (Berlin), 1990, 72, 1.
10 M. N. Bell, A. J. Blake, R. O. Gould, A. J. Holder, T. I. Hyde,
A. J. Lavery, G. Reid and M. Schröder, J. Inclusion Phenom., 1987,
5, 167.
Crystallography
11 A. J. Blake, W.-S. Li, M. Schröder, H. Richtzenhain and L. R.
Sutton, manuscript in preparation.
12 J. J. H. Edema, J. Buter, F. S. Schoonbeek, R. M. Kellogg, F. van
Bolhuis and A. L. Spek, Inorg. Chem., 1994, 33, 2448.
13 A. I. Vogel, Elementary Practical Organic Chemistry Part 2:
Table 4 summarises the crystal data, data collection, structure-
solution and refinement parameters for ligands L3–L5 and the
complex [Pd(L3)][BF4]2ؒ1.5MeCN. All structures were solved
using direct methods and all non-hydrogen atoms except for
those in disordered groups were refined anisotropically. Hydro-
gen atoms were placed in calculated positions and refined using
a riding model.
Qualitative Organic Analysis, Longmans, Green
& Co. Ltd.,
London, 2nd edn., 1966, pp. 113–119.
14 F. H. Allen and O. Kennard, Chem. Des. Autom. News, 1993, 8, 1,
31.
The asymmetric unit of the complex was found to contain
two MeCN sites, one of which was half-occupied: disorder of
the full-occupancy MeCN was successfully modelled by an
approximately equal distribution of two orientations. Disorder
15 C. A. Hunter, Chem. Soc. Rev., 1994, 23, 101.
16 N. N. Greenwood and A. Earnshaw, Chemistry of the Elements,
Pergamon, Oxford, 1984, p. 304.
17 (a) A. J. Blake, A. J. Holder, T. I. Hyde, H. J. Kuppers, M. Schröder,
S. Stotzel and K. Wieghardt, J. Chem. Soc., Chem. Commun., 1989,
1600; (b) P. Comba, A. Fath, B. Nuber and A. Peters, J. Org. Chem.
in the press.
18 G. R. Desiraju, Angew. Chem., Int. Ed. Engl., 1995, 34, 2311.
19 R. R. Thomas and A. Sen, Inorg. Synth., 1990, 28, 128; V. Y.
Kukushkin, Å. Oskarsson and L. I. Elding, Zh. Obsch. Khim., 1994,
64, 881.
20 G. M. Sheldrick, SHELXTL PC, version 5.03, Siemens Analytical
Instrumentation, Madison, WI, 1994.
Ϫ
in one BF4 was modelled using two-fold rotation about the
B(1)᎐F(1) vector, whilst the other was modelled as two tetra-
hedra with a common centre at B(2). Disorder in the cation was
modelled by a 180Њ rotation about the C(13)᎐N(15) vector with
a 65:35 random distribution. The symmetry of the unit cell
imparts the racemic nature of the crystal. The phenyl ring was
restrained to be flat to within 0.02 Å with C᎐C distances of
1.40(2) Å.
Structure solution and least-squares refinement for all crys-
tals was carried out using Dell Dimension 133 MHz Pentium
personal computers running SHELXTL PC software20 except
for the structure solution for L4 which was performed using
SHELXS 86.22
21 J. Cosier and A. M. Glazer, J. Appl. Crystallogr., 1986, 19, 105.
22 G. M. Sheldrick, SHELXS 86, Acta Crystallogr., Sect. A, 1990, 46,
467.
CCDC reference number 186/773.
Received 15th August 1997; Paper 7/05996E
284
J. Chem. Soc., Dalton Trans., 1998, Pages 279–284