Mesomorphic silver(I) complexes of polycatenar 2′- and 3′-stilbazoles. Crystal and molecular structure of 3,4-dimethoxy-3′- stilbazole and of two silver triflate complexes

Article abstract of DOI:10.1016/j.poly.2005.07.023

The synthesis of 3,4-dialkoxy and 3,4,5-trialkoxy derivatives of 2- and 3-stilbazole are reported along with their related complexes with silver dodecylsulphate and silver triflate. The single crystal structures of one ligand and two complexes are reporte

Full text of DOI:10.1016/j.poly.2005.07.023

Polyhedron 25 (2006) 307–324
www.elsevier.com/locate/poly
Mesomorphic silver(I) complexes of polycatenar 20- and
30-stilbazoles. Crystal and molecular structure of
3,4-dimethoxy-30-stilbazole and of two silver triflate complexes
d
c
c
Deborah M. Huck b,d, H. Loc Nguyen , Peter N. Horton , Michael B. Hursthouse ,
Daniel Guillon , Bertrand Donnio ,b, Duncan W. Bruce
b
a,
*
*
a
Department of Chemistry, University of York, Heslington, York Y10 5DD, UK
IPCMS-GMO, 23, Rue de Loess UMR7504 (CNRS-ULP), 67037 Strasbourg Cedex, France
b
c
EPSRC Crystallographic Service, Department of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, UK
d
Department of Chemistry, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
Received 14 June 2005; accepted 12 July 2005
Available online 12 September 2005
Dedicated to Malcolm Chisholm on the occasion of his sixtieth birthday.
Abstract
The synthesis of 3,4-dialkoxy and 3,4,5-trialkoxy derivatives of 2- and 3-stilbazole are reported along with their related complexes
with silver dodecylsulphate and silver triflate. The single crystal structures of one ligand and two complexes are reported. While none
of the complexes of the 2-stilbazoles is liquid-crystalline, several complexes of the 3-stilbazoles show columnar mesophases as char-
acterised by polarised optical microscopy and X-ray diffraction. The liquid crystal phase behaviour is compared with that of the
parent 4-stilbazole derivatives.
ꢀ 2005 Elsevier Ltd. All rights reserved.
Keywords: Metallomesogen; Silver; Stilbazole; Polycatenar; Liquid crystal
1. Introduction
to undertake systematic structure/function studies in
order to determine how the properties of the new sys-
tems may be compared with and understood in relation
to the existing literature. Both approaches have been
adopted in the study of metallomesogens, and one fea-
ture of the latter has been the extra structural flexibility
offered on account of the coordination around the metal
under study.
Our own work has contributed to both approaches to
the subject, but in particular regard to the latter, system-
atic approach, we have engaged extensively with the li-
quid crystal behaviour of stilbazoles in areas such as
hydrogen- [3] and halogen- [4] bonding as well in combi-
nation with metals [5]. In particular, we have looked at
both calamitic and polycatenar bis(ligand) metal com-
plexes of Pd, Pt [6] and Ag [7] and have looked at how
The study of metallomesogens [1,2] represents a ma-
jor subject within liquid crystals that has developed
strongly within the last twenty years or so. Large
swathes of the periodic table have been investigated
and a very large number of different elements have been
incorporated into mesomorphic systems in one way or
another. In a developing area such as this, there is a
simultaneous need constantly to discover new systems,
perhaps targeted because of particular properties, and
*
Corresponding author. Tel.: +44 1904 264188; fax: +44 1904
432516.
E-mail addresses: db519@york.ac.uk, d.bruce@exeter.ac.uk (D.W.
Bruce).
0277-5387/$ - see front matter ꢀ 2005 Elsevier Ltd. All rights reserved.
doi:10.1016/j.poly.2005.07.023

308
D.M. Huck et al. / Polyhedron 25 (2006) 307–324
control may be exercised over the nature of the phase
formed, particularly in relation to the formation of the
cubic phase [8], and the lamellar-to-columnar transition
in polycatenar systems [9].
systems showed a much more limited mesomorphism
and only the SmA phase was seen.
In order to complete this study, we then turned our
attention to polycatenar [11,12] systems. Our previous
investigations had shown that the 3,4-tetracatenar com-
plexes with DOS anions (2a) showed a progression from
cubic to columnar (Colh) phase as n increased, as did the
related triflate complexes (2b) but at longer chain
lengths. These results are consistent with arguments that
invoke surface curvature as a driving force for this tran-
sition by analogy with the behaviour of lyotropic mate-
rials [9,13]. The mesomorphism of the 3,5-tetracatenar
complexes (3a,b) and the hexacatenar complexes (4a,b)
was dominated by the formation of columnar phases
[14]. We have, therefore, undertaken the synthesis of
3,4-dialkoxy and 3,4,5-trialkoxy derivatives of 30- and
20-stilbazole, and have synthesised their complexes with
silver(I). This work, along with the characterisation of
the mesomorphism by optical microscopy and X-ray dif-
fraction, is now described.
Within these studies, silver(I) complexes have offered
the greatest opportunity for systematic evaluation due
both to the availability of a range of stilbazoles and to
the fact that the complexes are formally ionic making
different anions available. In our initial work with
4-alkoxy-40-stilbazoles (1, Fig. 1) we examined a range
of counter-anions, but as the work progressed to com-
plexes of di- and tri-alkoxy stilbazoles (2, 3 and 4,
Fig. 1), we settled on studies using triflate and alkyl
sulphates (mainly dodecylsulphate).
Having investigated the effect of ligand chain substi-
tution on these systems, more recently we turned our
attention to varying the structure of the core by synthes-
ising silver(I) complexes of a range of 4-alkoxy-20- and
30-stilbazoles (5 and 6, Fig. 2) [10]. Whereas with com-
plexes of the 4-stilbazoles we had found polymorphism
that included nematic and cubic phases, these isomeric
2. Synthesis
CnH2n+1
O
N
Ag+
X-
N
In previous studies where stilbazoles had been used,
we had employed either Heck coupling methodologies
[15] or condensation reactions [3b], but in the present
case, neither was particularly effective. Thus, here we
employed a Siegrist methodology [16,17] in which a ben-
zylidene group (derived from an imine) is transferred to
an aromatic aldehyde function leading to a 1,2-diaryl-
ethene with high stereoselectivity. The approach, which
we have used recently in the construction of prototypical
dendrimers [18], and has been used in the synthesis of re-
lated stilbazole systems [19], is very effective and allowed
access to the desired materials in good yield as indicated
in Scheme 1.
Thus, 3,4-dialkoxybenzaldehyde (from 3,4-dihydroxy-
benzaldehyde and the appropriate 1-bromoalkane) [13]
was reacted with aniline in ethanol to give N-phenyl-3,4-
dialkoxybenzaldimine in isolated yields of 89–97%. The
imine, which was used without further purification,
was then treated with either 3- or 2-picoline in dimethyl-
formamide in the presence of an excess of potassium
tert-butoxide to yield 3,4-dialkoxy-30-stilbazole (7) or 3,4-
dialkoxy-20-stilbazole(8),respectively,ascolourlesssolids
OCnH2n+1
1a: X = BF4
1b: X = NO3
1c: X = CF3SO3 (OTf)
1d: X = C8H17OSO3 (OS)
1e: X = C12H25OSO3 (DOS)
CnH2n+1
R
O
R'
N
Ag+
X-
N
R'
R
OCnH2n+1
2a: R = CnH2n+1O, R' = H, X = C12H25OSO3 (DOS)
2b: R = CnH2n+1O, R' = H, X = CF3SO3 (OTf)
3a: R = H, R' = CnH2n+1O, X = C12H25OSO3 (DOS)
3b: R = H, R' = CnH2n+1O, X = CF3SO3 (OTf)
4a: R = R' = CnH2n+1O, X = C12H25OSO3 (DOS)
4b: R = R' = CnH2n+1O, X = CF3SO3 (OTf)
Fig. 1. Calamitic (1) and polycatenar (2, 3 and 4) silver(I) complexes
of 4-stilbazoles.
CnH2n+1
O
CnH2n+1
O
N
N
Ag+
X-
Ag+
N
X-
N
OCnH2n+1
OCnH2n+1
5: X = C12H25OSO3 (DOS)
6a: X = C12H25OSO3 (DOS)
6b X = CF3SO3 (OTf)
Fig. 2. Structure of calamitic silver(I) complexes of 2- and 3-stilbazoles.

D.M. Huck et al. / Polyhedron 25 (2006) 307–324
309
CnH2n+1
O
R
CnH2n+1
O
R
H
O
H
N
(i)
CnH2n+1
O
CnH2n+1
O
(ii)
(ii)
N
N
CnH2n+1
O
CnH2n+1
O
CnH2n+1
O
CnH2n+1
O
N
N
R
R
7: R = H
9: R = CnH2n+1
8: R = H
10: R = CnH2n+1O
O
Scheme 1. Synthesis of the new stilbazole ligands: (i) Ph–NH2/EtOH/TsOH (cat); (ii) KOtBu/DMF (ligands are identified in the text as, e.g., 8-n,
where n refers to the number of carbons in the alkoxy chain).
in moderate-to-good yields (over 53–88%) after purifica-
tion by column chromatography on silica gel and crystal-
lisation from hot hexane. The trans nature of the two
isomeric compounds was confirmed by the 1H NMR spec-
tra with coupling constants of the AB systems of around
16 Hz. 3,4,5-Trialkoxystilbazoles (9 and 10) were pre-
pared similarly from 3,4,5-trialkoxybenzaldehyde [14].
The silver(I) dodecylsulfate complexes of all four
ligands were prepared by stirring the appropriate
stilbazole with silver(I) dodecylsulfate in dichlorometh-
ane at room temperature in the dark for 4 h, yielding
complexes 11a, 12a, 13a and 14a, respectively (Fig. 3).
The silver(I) triflate complexes were similarly accessed
using acetone as solvent to give complexes 11b, 12b,
13b and 14b (Fig. 3) in good yield.
moieties, namely, the pyridine ring (N1, C1 to C5)
bonded trans across a C=C double bond to a 3,4-
dimethoxystyryl group (C8 to C13, O1, C14, O2, C15).
The planar fragments are related by a dihedral angle
of 20.9(3)ꢁ. Although there are four possible ÔplanarÕ
conformations about the trans double bond (180ꢁ rota-
tions of the pyridyl and dimethoxyphenyl rings), only
one is observed in the crystal structure.
2.1.2. Bis(3,4-dimethoxy-30-stilbazole)silver(I) triflate
(11b-1)
Two views of the structure are shown in Fig. 5. The
molecular structure is quite complex, with two conforma-
tionally differing silver complexes in the asymmetric unit.
Here three of the 3,4-dimethoxy-30-stilbazole ligands (la-
belled A, B and C) adopt the same basic conformation as
observed for 7-1, but with slightly varying degrees of twist
(16.1(4)ꢁ, 13.2(4)ꢁ, 14.7(5)ꢁ). The fourth (labelled D) has
the pyridyl group rotated by 180ꢁ about the C64–C66
bond with respect to the other ligands. It still has adopts
a similar twist (15.5(4)ꢁ). Although there are no Ag–Ag
close contacts, there are Ag–Otriflate contactsranging from
2.1. Crystal and molecular structure of 3,4-dimethoxy-30-
stilbazole and of complexes 11b-1 and 11b-4
In order to obtain more detailed information about
the conformation of these new polycatenar stilbazoles
and some of their complexes, 3,4-dimethoxy-30-stilbaz-
ole was prepared and single crystals grown successfully
by crystallisation from hexane. Single crystals of the sil-
ver triflate complex of this ligand (11b-1) and of the re-
lated 3,4-butyloxy-30-stilbazole (11b-4) were also
obtained from dichloromethane/methanol and from
hot hexane, respectively. Crystallographic data are col-
lected in Table 1.
˚
2.84(1)–3.13(1) A. These are similar, if a touch longer,
than those found in known silver triflate complexes. In
fact the triflate anions act as bridges between the two dif-
fering silver complexes with the third oxygen of each tri-
flate co-ordinating towards the disordered water
molecule. This results in an infinite slipped stack (Fig. 6).
2.1.3. Bis(3,4-dibutyloxy-30-stilbazole)silver(I) triflate
(11b-4)
2.1.1. 3,4-Dimethoxy-30-stilbazole (7-1)
Two views of the structure are shown in Fig. 4. The
molecular structure consists of two essentially planar
Two views of the structure are shown in Fig. 7 and
structural refinement parameters and crystal data are

310
D.M. Huck et al. / Polyhedron 25 (2006) 307–324
OCnH2n+1
CnH2n+1
O
CnH2n+1
CnH2n+1
O
O
N
N
Ag+
N
OCnH2n+1
OCnH2n+1
Ag+ X–
N
X–
OCnH2n+1
OCnH2n+1
11a: X = DOS
11b: X = OTf
12a: X = DOS
12b: X = OTf
OCnH2n+1
CnH2n+1
O
O
CnH2n+1
CnH2n+1
CnH2n+1
O
O
N
N
OCnH2n+1
Ag+
N
OCnH2n+1
X–
Ag+ X–
OCnH2n+1
N
OCnH2n+1
OCnH2n+1
OCnH2n+1
13a: X = DOS
13b: X = OTf
14a: X = DOS
14b: X = OTf
OCnH2n+1
Fig. 3. Structure of the new silver stilbazole complexes (complexes are identified in the text as, e.g., 14a-n, where n refers to the number of carbons in
the alkoxy chain).
Table 1
Crystallographic data for 7-1, 11b-1 and 11b-4
Compound 7-1
Compound 11b-1
Compound 11b-4
Empirical formula
Formula weight (g molꢀ1
Temperature (K)
Crystal system
Space group
Unit cell dimensions
C
241.28
298(2)
orthorhombic
Pbca
15H15NO2
C62H61Ag2F6N4O15S2
1496.01
120(2)
monoclinic
Cc
C86H108Ag2F6N4O14S2
1815.62
120(2)
)
triclinic
ꢀ
P1
˚
a (A)
17.0538(8)
6.7808(3)
22.2685(10)
22.6036(4)
12.0562(2)
24.8145(5)
10.3538(2)
16.3472(2)
26.6281(5)
93.408(1)
99.849(1)
102.717(1)
4309.44(13)
2
˚
b (A)
˚
c (A)
a (ꢁ)
b (ꢁ)
c (ꢁ)
113.549(1)
3
˚
Volume (A )
2575.1(2)
8
1.245
0.083
1024
6199.1(2)
4
1.603
0.788
3044
Z
Dcalc (Mg mꢀ3
Absorption coefficient (mmꢀ1
F(000)
)
1.399
0.579
1888
)
Crystal
block; colourless
0.10 · 0.08 · 0.07
6.74–27.48ꢁ
13309
2887 [Rint = 0.1661]
97.6%
slab; colourless
0.35 · 0.26 · 0.06
2.99–27.48ꢁ
39248
13877 [Rint = 0.0482]
99.7%
plate; colourless
0.40 · 0.16 · 0.03
2.96–27.48ꢁ
81933
19556 [Rint = 0.0681]
98.8%
Crystal size (mm3)
h Range for data collection
Reflections collected
Independent reflections
Completeness to h = 27.48ꢁ
Absorption correction
Goodness-of-fit on F2
Final R indices [F2 > 2r(F2)]
R indices (all data)
semi-empirical from equivalents semi-empirical from equivalents semi-empirical from equivalents
0.989
R1 = 0.0830, wR2 = 0.2249
R1 = 0.2641, wR2 = 0.3227
0.461 and ꢀ0.118
1.031
1.006
R1 = 0.0587, wR2 = 0.1423
R1 = 0.0869, wR2 = 0.1586
1.572 and ꢀ0.604
R1 = 0.0412, wR2 = 0.0792
R1 = 0.0774, wR2 = 0.0897
0.863 and ꢀ0.607
ꢀ3
˚
Largest differential peak and hole (e A
)
summarised in Table 1. The molecular structure is di-
meric and as such is broadly the same as that found
for the silver(I) octylsulfate and silver(I) perchlorate
complexes described by, for example, Adams et al. [20]
and Gallardo et al. [21], respectively. It consists of two
essentially planar bis(3,4-dibutoxy-30-stilbazole)silver(I)

D.M. Huck et al. / Polyhedron 25 (2006) 307–324
311
ingly the stilbazoles that adopt the same conformation
as 7-1 exhibit a greater twist (19.4(1)ꢁ and 33.6(1)ꢁ) com-
pared to the two that adopt the inverse (13.9(1)ꢁ and
10.7(1)ꢁ).
Of course, one thing that is not known in relation to
both silver complexes is the nature of the species present
in the mesophase. Previously, structural arguments have
suggested [13] that the dimeric structure is maintained in
the columnar phase of mesomorphic, polycatenar DOS
salts and this may be the case here, too, but in the ab-
sence of hard information, the discussion of the meso-
morphism found below will make no assumptions
about the state of aggregation.
2.2. Mesomorphism of the new silver(I) complexes
The mesomorphic behaviour of the new complexes
was studied by polarised optical microscopy, differential
scanning calorimetry (DSC), X-ray diffraction and mis-
cibility studies. The thermal behaviour of the new com-
plexes is collected in Table 2 and we found that the
compounds behaved reproducibly over the lifetime of
the DSC and microscopy experiments carried out.
Neither of the new 3,4-dialkoxy-20-stilbazole ligands
(8) was mesomorphic, rather melting to an isotropic li-
quid at 55.2 ꢁC for n = 8 and at 68.7 ꢁC for n = 12,
and complexation of these two ligands to AgDOS
(12a) or AgOTf (12b) did not lead to mesomorphic
materials.
However, complexation of the non-mesomorphic 3,4-
dialkoxy-30-stilbazoles (7) with the two silver complexes
did lead to mesomorphic, materials providing the alkoxy
chain was long enough. Whilst the un-complexed ligand
was not mesomorphic, melting straight to the isotropic
phase between 54.2 ꢁC for n = 4 and 68.0 ꢁC for
n = 12, complex 11a was mesomorphic for 6 6n 6 12,
with all homologues displaying a columnar hexagonal
phase, characterised by its optical texture (Fig. 8).
Fig. 4. Molecular structure of the 3,4-dimethoxy-30-stilbazole.
cations that are arranged parallel to one another, sup-
ported by the two triflate anions. The Ag–Ag distance
˚
is 3.136(1) A which is very similar to the equivalent dis-
˚
tance in the octylsulfate (ca. 3.2 A) and perchlorate (ca.
˚
3.35 A) salts. The triflate anions effectively bridge the di-
meric structure and there are three, ionic Ag–O contacts
˚
˚
at about 2.8 A with a fourth Ag–O distance of 3.4 A.
This is slightly different from the octylsulfate and per-
chlorate structures where all four Ag–O distances are
˚
in the range 2.7–2.9 A. Here, there are no strong interac-
tions beyond the dimer and its pair of triflate anions.
Also, and as can be seen clearly in Fig. 7, the stilbazoles
exist in two differing conformations. Thus, two of the
stilbazoles adopt the same conformation as 7-1, while
the other two adopt its ÔinverseÕ (i.e. both rings rotated
by 180ꢁ with respect to the trans double bond). Interest-
Fig. 5. Two views of the structure of the silver(I) triflate complex of 3,4-dimethoxy-30-stilbazole.

312
D.M. Huck et al. / Polyhedron 25 (2006) 307–324
Fig. 6. Two views of the slipped-stack arrangement of 11b-1.
Fig. 7. Two views of the structure of the silver(I) triflate complex of 3,4-dibutyloxy-30-stilbazole.

D.M. Huck et al. / Polyhedron 25 (2006) 307–324
313
Table 2
Thermal data for the new complexes
Complex
n
Transition
T (ꢁC) DH
(kJ molꢀ1
DS
)
(J Kꢀ1 molꢀ1
)
11a
4
6
8
Cr1 ! Cr2
Cr2 ! I
93.6
99.8
36.5
60.0
57.6
80.9
75.2
94.9
48.7
65.4
75.7
95.7
28.8
10.3
44.5
0.5
84.1
1.3
72.3
1.5
1.2
79
28
144
2
254
3
208
4
4
Cr ! Colh
Colh ! I
Cr ! Colh
Colh ! I
10 Cr ! Colh
Colh ! I
12 Cr1 ! Cr2
Cr2 ! Cr3
26.0
39.1
1.4
77
112
4
Cr3 ! Colh
Colh ! I
11b
4
Cr1 ! Cr2
Cr2 ! I
152.7
167.5
141.2
103.3
114.2
54.9
1.6
43.1
31.3
16.9
22.4
29.4
1.5
44.6
(ꢀ1.4)
51.8
49.5
1.6
4
98
76
45
58
Fig. 8. The optical texture of the columnar hexagonal phase of 11a-12
on cooling from the isotropic phase at 93.4 ꢁC.
6
8
Cr ! I
Cr1 ! Cr2
Cr2 ! I
10 Cr1 ! Cr2
Cr2 ! Cr3
90
4
alkoxy-30-stilbazoles to silver(I) dodecylsulfate or
silver(I) triflate resulted in complexes (13a and 13b) that
were mesomorphic. The octyloxy homologue of com-
plex 13a was already in a columnar hexagonal meso-
phase at room temperature and cleared to the
isotropic phase on heating to 86.8 ꢁC. The dodecyloxy
homologue also showed a columnar hexagonal phase
from 37.1 to 81.2 ꢁC, a smaller temperature range than
for n = 8. These mesophases were characterised by opti-
cal microscopy.
Bis(3,4,5-trioctyloxy-30-stilbazole)silver(I) triflate was
a pasty solid that melted at 39.8 ꢁC to a columnar hex-
agonal phase which cleared to the isotropic at
105.3 ꢁC. The mesophase was characterised by polarised
optical microscopy from its optical texture. The dode-
cyloxy homologue of complex 13b showed two crystal
phases before melting to a columnar hexagonal phase
at 50.0 ꢁC and clearing at 119.8 ꢁC. On cooling, the mes-
ophase reappeared at 117 ꢁC and remained until crystal-
lisation at 21.8 ꢁC. On second heating, the complex
melted straight into the mesophase at 30.4 ꢁC but
cleared at the same temperature as the first heating. Sub-
sequent cooling and heating repeated the behaviour of
the second cycle so crystallisation from a solvent must
result in a crystalline form that needs to rearrange on
heating before it can melt into the mesophase. The
columnar hexagonal phase was characterised from its
optical texture (Fig. 9).
69.4
Cr3 ! I
101.4
(93.2)
63.5
118
(ꢀ4)
154
130
4
(I ! Colh)
12 Cr1 ! Cr2
Cr2 ! Colh 107.0
Colh ! I
114.0
12a
12b
8
Cr1 ! Cr2
52.9
104.9
52.0
68.3
80.5
20.3
60.3
10.2
66.7
17.8
62
160
31
196
50
Cr2 ! I
12 Cr1 ! Cr2
Cr2 ! Cr3
Cr3 ! I
8
Cr1 ! Cr2
66.8
107.5
54.8
20.3
33.7
99.5
11.9
60
88
304
34
Cr2 ! I
12 Cr1 ! Cr2
Cr2 ! I
81.2
13a
13b
8
Colh ! Ia
86.8
37.1
81.2
2.2
101.1
3.2
6
326
9
12 Cr ! Colh
Colh ! I
4
8
Cr ! I
189.0
39.8
105.3
42.2
50.0
119.8
35.6
49.5
2.3
70.2
13.0
1.5
77
158
6
227
40
4
Cr ! Colh
Colh ! I
12 Cr1 ! Cr2
Cr2 ! Colh
Colh ! I
14a
8
Cr1 ! Cr2
47.5
67.7
47.2
57.7
15.5
29.5
22.7
68.1
48
87
71
Cr2 ! I
12 Cr1 ! Cr2
Cr2 ! I
12 Cr1 ! I
206
14b
55.4
93.2
284
a
Complex was in the mesophase at room temperature.
2.3. X-ray diffraction
Two of the complexes 11b were mesomorphic showing a
columnar hexagonal phase over a narrow temperature
range, monotropic for n = 10 and enantiotropic for
n = 12.
None of the new 3,4,5-trialkoxystilbazole ligands
(9 or 10) was mesomorphic and all melted directly into
the isotropic phase. However, complexation of 3,4,5-tri-
X-ray diffractions studies were carried out on com-
plexes 11a, 11b, 13a and 13b, and the results for complex
11a, 13a and 13b are collected in Table 3, which contains
both experimental and, in parentheses for cases with >1
observed reflection, calculated lattice parameters; the
lattice parameter, a, and columnar cross-sectional area,

314
D.M. Huck et al. / Polyhedron 25 (2006) 307–324
in the patterns corresponding to the squared spacing
ratios 1:3, and to the indexation (h k) = (1 0) and (1 1),
as shown in Fig. 10. Diffuse reflections were also re-
˚
corded for all complexes at around 4.5 A, which corre-
sponds to the liquid-like order of the molten alkoxy
˚
chains, and at around 10 A, which may be due to loose
interactions between dimeric species formed by these sil-
ver complexes [10].
The lattice parameter a, for the dodecyloxy homo-
˚
logue was found to be ca. 42 A, which is around
˚
12 A smaller than the estimated length of the complex
˚
in its most extended form (53.8 A). It is possible that
this is due to the way the molecules may pack together
in the repeat unit with the chains curled round in order
to fill space efficiently (Fig. 11). However, another
possibility is that in common with the generalised model
for the packing of polycatenar mesogens that some of
us advanced recently [22], the complexes can tilt at
some angle within the column or otherwise organise
to give a circular cross-section normal to the column
direction that then allows formation of a columnar
phase of hexagonal symmetry. The model in Fig. 11
would be one possible expression of this general
approach.
Fig. 9. The optical texture of the columnar hexagonal phase of 13b-12
on cooling from the isotropic phase at 41.9 ꢁC.
S, are derived from calculated data where these are
available. Due to the small temperature range of the
mesophases of 11b, no conclusive results were obtained
by X-ray diffraction studies so the mesophase remains
assigned from its optical texture alone.
For 11a-12 the X-ray diffraction studies confirmed
the assignment of the mesophase as columnar hexagonal
since two, sharp, small-angle reflections were observed
Table 3
X-ray diffraction data for complexes 11a, 13a and 13b
2
˚
˚
˚
˚
˚
˚
Complex
n
T (ꢁC)
d10 (A)
d11 (A)
d20 (A)
d21 (A)
a (A)
S (A )
11a
6
8
60
50
40
80
75
70
65
90
85
80
95
31.3
31.4
31.6
33.2
33.6
33.9
34.2
34.0
34.4
34.8
34.5
(34.5)
36.2
(36.2)
36.5
(36.5)
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
36.1
36.3
36.4
38.3
38.8
39.1
39.5
39.3
39.7
40.2
1131
1138
1153
1272
1303
1327
1351
1334
1366
1398
10
12
–
–
19.9
(19.9)
20.9
(20.9)
21.1
(21.1)
39.8
41.8
42.15
1374
1513
1538
90
85
–
–
–
–
13a
12
80
70
60
50
32.15
(32.15)
32.7
(32.7)
33.25
(33.25)
33.9
18.6
(18.6)
19.0
(18.9)
19.2
15.6
(16.1)
16.1
(16.35)
16.7
12.5
(12.15)
12.5
(12.35)
12.5
37.1
1197
1235
1276
1327
37.75
38.4
(19.2)
19.6
(16.6)
16.9
(12.6)
12.8
(33.9)
(19.6)
(16.95)
(12.8)
39.15
13b
12
80
50
35.0
(35.0)
36.4
20.2
(20.2)
21.0
–
–
1
–
40.4
42.0
1415
1530
–
(36.4)
(21.0)
pffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi
P
The calculated value of the reflections is deduced from the mathematical expression: hd10i ¼
ð
h kdh k
.
h2 þ k2 þ hkÞ, where Nh k is the number
Nh k
2
pffiffi
of h k reflections for the Colh phase; a is the lattice parameter of the Colh phase ða ¼ hd10iÞ, S is the lattice area (S = aÆd10æ).
3

D.M. Huck et al. / Polyhedron 25 (2006) 307–324
315
chain homologues of 11a as Colh and indeed, given the
comparison of the d(10) data within the homologous
series (Table 3), this is our assignment, which we believe
to be sound.
5000
35000
30000
25000
20000
15000
10000
5000
0
X-ray diffraction studies of 13a-12 confirmed the
columnar hexagonal nature of the mesophase displayed
(Table 3) since four, sharp, small-angle reflections were
observed (Fig. 13), corresponding to the squared spac-
ing ratios 1, 3, 4 and 7 with indexation (h k) = (1 0),
(1 1), (2 0) and (2 1). In the case of 13b-12, two, sharp,
small-angle reflections were observed in the diffraction
pattern corresponding to the squared spacing ratios 1
and 3 with indexation (h k) = (1 0) and (1 1). For 13a-
12 and 13b-12, the lattice parameter, a, was around 14
d11
d10
I
0
1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5
Diffuse
Diffuse
halo
halo
˚
and 11 A shorter, respectively, than the estimated length
˚
of the complexes in their most extended form (53.8 A).
This behaviour was discussed above. Shorter-chain
homologues of both triflate and DOS salts were charac-
terised by optical microscopy alone since no satisfactory
X-ray results were obtained.
5
10
15
2θ
20
25
30
Fig. 10. X-ray diffraction pattern of 11a-12 at 90 ꢁC.
3. Discussion
Fig. 14 summarises the thermal behaviour of com-
plexes 11a and 12a and compares it with the behaviour
of the ÔparentÕ complexes bis(3,4-dialkoxy-40-stilbaz-
ole)silver(I) dodecylsulfate (2a) (see Fig. 15).
O
O
N
The most noticeable difference in the mesomor-
phism of these three complexes is in the number of
mesophases displayed. Thus, the parent complex (2a)
+
Ag
O
N
O
O
N
O
+
is polymorphic and shows
a
cubic phase for
Ag
O
N
4 6 n 6 10 and a Colh phase for 6 6 n 6 12. Complex
11a, however, shows only one mesophase, namely a
columnar hexagonal phase for n P 6. Thus, the melt-
ing point drops steeply from n = 4 (99.8 ꢁC) to n = 6
(36.5 ꢁC) and at the latter chain length a Colh phase
is introduced. The temperature range of the mesophase
stays roughly constant with chain length (between 23
and 20 ꢁC), but the temperature at which the phase
is seen does increase with chain length (TCol-I = 60.0,
80.9, 94.9 and 95.7 ꢁC for n = 6, 8, 10 and 12, respec-
tively). Combined with the very limited mesomorphism
of the triflate analogues (11b) and the absence of
mesomorphism in all the tetracatenar complexes of
the 2-stilbazoles, the observations once more suggest
a profound effect consequent on the reduction in
anisotropy associated with the isomeric ligands.
In these complexes, the dodecylsulfate anion acts as a
flexible lateral substituent and, therefore, prevents effi-
cient packing of the molecules so the transition tempera-
tures are lowered. Since the core length of these silver(I)
complexes of the 3-stilbazole ligand is shorter than that
of the complexes of the 4-stilbazole ligand, the dodecyl-
sulfate alkyl chain is expected to extend beyond the length
of the silver(I) core as it does in the case of the ÔparentÕ [7].
O
O
N
O
+
Ag
N
O
O
Fig. 11. Schematic of the possible packing of molecules in a columnar
repeat unit.
For complexes 11a with n = 6, 8 and 10, only one
reflection was observed and so it was impossible to make
an unequivocal assignment of the mesophase symmetry
on this basis. Thus, to try to confirm the identity of the
phase they form, contact preparations were carried out.
Contact preparations between compound 11a-12 and
either compound 11a-8 or 11a-10 failed to show any
miscibility as shown for 11a-10 and 11a-8 in Fig. 12;
the same experiment for 11a-6 was impossible due to
incompatible temperature ranges. Such immiscibility
does not preclude assignment of the phase of the shorter

316
D.M. Huck et al. / Polyhedron 25 (2006) 307–324
Fig. 12. Contact preparation (a) at 88.7 ꢁC between the Colh phase of complex 11a-12 (left) and the unidentified mesophase of complex 11a-10
(right), and (b) at 79.9 ꢁC between 11a-12 (left) and 11a-8 (right). Lines of immiscibility are indicated by arrows.
This affects the balance between the relative volumes of
4000
d
11 = 19.0 Å
d20 =16.1 Å
the core and the chain, a factor known to be important
in determining the mesomorphism of polycatenar sys-
tems [7,9]. On this basis, the absence of a cubic phase in
these isomeric materials may be rationalised. Further, it
appears true that cubic phase formation requires the pres-
ence of discrete molecular aggregates [8,9,23], and the in-
creased steric congestion caused by the reduction in
ligand and complex anisotropy, as evidenced in the fig-
ures above from the crystal structures, may be the cause.
Because, in general, the mesomorphism of 3,4,5-hex-
acatenar complexes is restricted to a columnar phase,
few examples were synthesised. In common with the pre-
ceding materials, none of the 2-stilbazole derivatives was
mesomorphic and they melted between 55 and 67 ꢁC
with little apparent dependence on the anion.
70000
60000
50000
40000
30000
20000
10000
0
d10 = 33.7 Å
2000
0
1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0
5
10
15
2θ
20
25
30
Fig. 13. X-ray diffraction pattern for 13a-12 at 70 ꢁC.
n = 4
n = 6
n = 8
n = 12
n = 10
180
160
140
120
100
80
Cry
Cub
Col
60
40
2a
12a11a
11a
12a
11a2a
2a
11a
11a 2a
2a
Complex
Fig. 14. Comparison of the thermal behaviour of complexes 11a and 12a with their ÔparentÕ complex 2a.

D.M. Huck et al. / Polyhedron 25 (2006) 307–324
317
160
120
80
160
I
I
120
T
T
Crys
Colh
Colh
80
Crys
10
40
40
2
4
6
8
10
12
2
4
6
8
12
Chain Length
a
Chain Length
b
Fig. 15. Phase diagrams of complexes 11a (a) and 11b (b) plotted on the same scale.
4. Experimental
Suitable single crystals were selected and data col-
lected on a Bruker Nonius KappaCCD Area Detector
at the window of a Bruker Nonius FR591 rotating anode
(kMo Ka = 0.71073 A) driven by COLLECT [24] and
DENZO [25] software at 120 K. The structure was deter-
mined in SHELXS-97 [26] and refined using SHELXL-97 [27].
All solvents and chemicals were used as received,
apart from THF which was dried by distillation over
sodium and benzophenone immediately prior to use
under an atmosphere of oxygen-free nitrogen. NMR
spectra were recorded on a Bruker DRX-400, ACF
300 or ACF-200, operating at 400, 300 or 200 MHz,
respectively, for protons and 100.6, 75.4 or
50.3 MHz, respectively, for carbon. Analysis by hot
stage microscopy was carried out using an Olympus
BX50 microscope equipped with a Link-Am HFS91
hot stage, and TMS92 controller and LNP2 cooling
unit. Analysis by DSC was carried out on a Perkin–El-
mer DSC7 instrument using heating and cooling rates
of 10 and 5 K minꢀ1. All analytical data are collected
in Table 4.
˚
4.1. Preparation of 3,4-dialkoxybenzylideneaniline
All homologues were made in the same way as 3,4-
dioctyloxybenzylidene aniline described.
3,4-Dioctyloxybenzaldehyde (1.09 g, 3.0 mmol) was
dissolved in ethanol (60 cm3) and aniline (0.39 g,
4.2 mmol) was added. A few crystals of para-toluene sul-
fonic acid were added and the solution became yellow. It
was stirred at room temperature for 2 h after which time
there was no precipitate, so the mixture was placed in
the freezer for 15 h. A white fluffy solid precipitated
and was filtered off and used without further purification
(1.27 g, 97%). For the longer-chain homologues, heating
was required to dissolve the starting benzaldehyde and
the product precipitated upon cooling the solution to
room temperature.
The XRD patterns were obtained with two different
experimental set-ups. In the first, a linear monochro-
matic Cu Ka1 beam (k = 1.5405 A) was obtained using
˚
a
Guinier camera with a sealed-tube generator
(900 W). In the second, a Debye–Scherrer camera
equipped with a bent quartz monochromator and an
electric oven was used. In both cases, the crude powder
was filled in Lindemann capillaries of 1 mm diameter.
An initial set of diffraction patterns was recorded with
a curved Inel CPS 120 counter gas-filled detector linked
o' n'
m' l'
CH3(CH2)5CH2CH2O
g
h
e
c
b
CH3(CH2)5CH2CH2O
i
f
˚
a
to a data acquisition computer; periodicities up to 60 A
N
o
n
m l
d
j
k
can be measured, and the sample temperature controlled
to within 0.05 ꢁC. The second set of diffraction pat-
terns was recorded on an image plate; cell parameters
were calculated from the position of the sharp reflections
at the smallest Bragg angle, which were in all cases the
1H NMR (400 MHz, CD2Cl2): d = 8.39 (1H, s, He),
4
7.60 (1H, d, Hg, JHH = 1.4 Hz), 7.42 (2H, m, Hb),
3
4
7.35 (1H, dd, Hk, JHH = 8.2 Hz, JHH = 1.4 Hz), 7.24
(1H, m, Ha), 7.23 (2H, m, Hc), 6.97 (1H, d, Hj,
3
3JHH = 8.2 Hz) 4.11 (2H, t, Hl0, JHH = 6.6 Hz), 4.09
˚
most intense. Periodicities up to 90 A can be measured,
3
and the sample temperature controlled to within
0.3 ꢁC. In each case, exposure times were varied from
1 to 24 h depending on the mesophase being observed
and upon the specific reflections being sought (weaker
reflections obviously taking longer exposure times).
(2H, t, H1, JHH = 6.6 Hz), 1.87 (2H, m, Hm0), 1.84
(2H, m, Hm), 1.44 (20H, m, Hn, Hn0), 0.92 (6H, 2 · t,
3
Ho, Ho0, JHH = 6.7 Hz).
13C NMR (100.61 MHz, CD2Cl2): d = 160.1 (e),
152.8, 152.7 (i,d), 149.9 (h), 129.9 (f), 129.5 (b), 125.8

318
D.M. Huck et al. / Polyhedron 25 (2006) 307–324
Table 4
Yields and analytical data for the new compounds
Compound
n
Yield (%)
MPt (ꢁC)
Elemental analysis calculated (found) (%)
C
H
N
6
6
8
10
12
89
97
91
91
42.4
51.6
61.0
68.8
78.7 (78.6)
79.6 (79.5)
80.3 (80.1)
80.8 (80.8)
9.3 (9.2)
3.5 (3.6)
3.2 (3.1)
2.8 (2.9)
2.6 (2.7)
9.9 (9.9)
10.4 (10.4)
10.8 (10.9)
7
8
4
6
8
10
12
53
73
55
73
64
54.2
50.6
46.3
55.0
68.0
77.5 (77.5)
78.7 (78.6)
79.6 (79.4)
80.3 (80.2)
80.8 (80.6)
8.4 (8.4)
9.3 (9.3)
9.9 (9.9)
10.4 (10.5)
10.8 (10.7)
4.3 (4.4)
3.7 (3.8)
3.2 (3.3)
2.8 (2.9)
2.6 (2.7)
8
12
12
88
59
88
55.2
68.7
39.8
79.6 (79.5)
80.8 (80.8)
80.2 (80.0)
9.9 (9.9)
10.8 (10.9)
11.4 (11.3)
3.2 (3.3)
2.6 (2.7)
1.9 (1.9)
9
8
12
93
88
oil
42.6
78.5 (78.3)
80.2 (80.0)
10.5 (10.6)
11.4 (11.6)
2.5 (2.7)
1.9 (2.0)
10
11a
8
12
78
53
oil
41.2
78.5 (78.1)
80.2 (79.9)
10.5 (10.6)
11.4 (11.6)
2.5 (2.6)
1.9 (2.0)
4
6
8
10
12
66
39
89
60
88
95.9
30.6
56.5
75.4
73.4
63.3 (63.2)
65.5 (65.5)
67.3 (67.1)
68.9 (69.0)
70.1 (70.2)
7.8 (8.0)
8.4 (8.5)
9.0 (9.0)
9.4 (9.5)
9.8 (9.9)
2.7 (2.6)
2.5 (2.6)
2.2 (2.4)
2.1 (2.2)
1.9 (2.0)
11b
4
6
8
10
12
86
71
60
89
86
167.5
141.2
114.2
101.4
107.0
56.9 (56.7)
60.1 (59.8)
62.6 (62.6)
64.7 (64.5)
66.4 (66.4)
6.0 (6.0)
6.9 (7.0)
7.7 (7.7)
8.3 (8.5)
8.8 (9.1)
3.1 (2.9)
2.8 (3.0)
2.5 (2.6)
2.3 (2.4)
2.1 (2.2)
12a
12b
13a
13b
8
12
62
59
103.4
68.0
67.3 (67.5)
70.1 (73.6)
9.0 (8.9)
9.8 (10.1)
2.2 (2.4)
1.9 (2.1)
8
12
74
85
107.5
81.2
62.6 (62.7)
66.4 (65.9)
7.7 (7.7)
8.8 (8.8)
2.5 (2.5)
2.1 (2.1)
8
12
54
56
Below rt
37.1
68.6 (68.7)
71.7 (71.6)
9.6 (9.7)
10.5 (10.5)
1.9 (1.9)
1.5 (1.1)
4
8
12
53
56
89
189.0
39.8
50.0
58.2 (57.9)
64.9 (64.6)
68.9 (68.6)
6.7 (6.7)
8.6 (8.6)
9.7 (9.6)
2.7 (2.7)
2.0 (2.0)
1.7 (1.7)
14a
14b
8
12
57
67
67.7
57.7
68.6 (68.8)
71.7 (71.7)
9.6 (9.6)
10.5 (10.5)
1.9 (1.9)
1.5 (1.6)
12
84
55.4
68.9 (68.4)
9.7 (9.7)
10.6 (1.0)
(a), 124.4 (k), 121.2 (c), 112.9 (j), 111.8 (g), 69.5 (l, l0),
32.3, 30.1, 30.0, 29.8, 29.7, 29.6, 26.4, 23.1 (m, m0, n, n0),
14.3 (o, o0).
3,4-Didodecyloxybenzylidene aniline (5.00 g, 10.1
mmol) was dissolved with heating in DMF (50 cm3).
3-Picoline (0.82 g, 8.8 mmol) was added with stirring,
followed by potassium tert-butoxide (4.40 g, 36.0 mmol)
in fractions. The solution immediately turned dark red.
The system was heated to 80 ꢁC and was stirred for
2.5 h. After cooling, HCl solution (10%) was added
dropwise until the pH of the mixture was neutral. Water
(100 cm3) was added and the solution became yellow.
The product was extracted into DCM (2 · 75 cm3) and
was washed with NaHCO3 solution (200 cm3 saturated)
and water (200 cm3). The organic phase was dried over
magnesium sulfate and the DCM was removed. The
4.2. Preparation of 3,4-dialkoxy-30-stilbazole (7) and
3,4-dialkoxy-20-stilbazole (8)
The preparation of 3,4-dodecyloxy-30-stilbazole will
be described; the same method was used for the other
homologues. The series of 3,4-didecyloxy-20-stilbazoles
were made in the same way except that 3-picoline was
replaced by 2-picoline. The reaction was carried out in
an atmosphere of argon.

D.M. Huck et al. / Polyhedron 25 (2006) 307–324
319
residue was then taken into toluene (100 cm3) and
washed repeatedly with water (4 · 100 cm3) to remove
the DMF. The toluene was then removed in vacuo to
leave a light brown solid. This was purified by column
chromatography on silica gel using DCM:methanol,
100:1 as eluant. A few drops of triethylamine were
added to prevent the stilbazole sticking to the column.
The product was then crystallised from hot hexane to
give a colourless powder (3.17 g, 73%).
13C NMR (100.61 MHz, CDCl3): d = 155.9 (e), 149.8
(j), 149.5 (a), 149.2 (k), 136.5 (g), 132.8 (g), 129.6 (h),
125.8 (f), 121.7 (b), 121.6 (d), 120.9 (m), 113.4 (l),
111.7 (i), 69.3 (n), 69.2 (n0), 31.8, 29.4, 29.3, 29.2, 26.0,
22.7 (o, o0, p, p0, q, q0), 14.1 (r, r0).
4.3. Preparation of 3,4,5-trialkoxybenzylideneaniline
3,4,5-Trioctyloxybenzylidene aniline was prepared in
the same way as 3,4,5-tridodecyloxybenzylidene aniline,
which is described.
n' o' p'
q'
r'
3,4,5-Tridodecyloxybenzaldehyde (7.90 g, 12.0 mmol)
was heated with stirring in ethanol (150 cm3) until it dis-
solved. Aniline (1.58 g, 17.0 mmol) was then added fol-
lowed by a few crystals of toluene sulphonic acid. The
mixture was stirred and was allowed to cool to room
temperature, as it did so a thick, white precipitate
formed. The mixture was stirred for a further 2 h and
the colourless precipitate was then filtered off and dried
in a dessicator (7.67 g, 10.5 mmol, 88% yield). It was
used without further purification.
c
d
a
OCH2CH2CH2(CH2)4CH3
j
i
f
b
e
h
N
OCH2CH2CH2(CH2)4CH3
k
g
n
o
p
q
r
m l
(7)
1H NMR (400 MHz, CDCl3): d = 8.70 (1H, d, Ha,
3
4JHH = 1.8 Hz), 8.46 (1H, dd, Hb, JHH = 4.7 Hz,
4JHH = 1.8 Hz),
7.81
(1H,
dt,
Hd,
3JHH
=
7.9 Hz, 2 · 4JHH = 1.8 Hz), 7.28 (1H, dd, Hc,
3JHH = 7.9 Hz, JHH = 4.7 Hz), 7.10 (1H, AB, Hg,
JAB = 16.4 Hz), 7.09 (1H, d, Hi, JHH = 1.9 Hz), 7.06
3
m' l'
k' j'
4
CH3(CH2)9CH2CH2O
g
h
3
4
(1H, dd, Hm, Jrm
8.3 Hz, JHH = 1.9 Hz), 6.92
e
c
b
HH
CH3(CH2)9CH2CH2O
i
(1H, AB, Hf, JAB = 16.4 Hz), 6.87 (1H, d, Hl,
f
a
m
l
k
j
N
3
3JHH = 8.3 Hz), 4.06 (2H, t, Hn0, JHH = 6.7 Hz), 4.02
d
CH3(CH2)9CH2CH2O
m' l' k' j'
3
(2H, t, Hn, JHH = 6.8 Hz), 1.84 (4H, m, Ho, Ho0),
1.50 (4H, m, Hp, Hp0), 1.33 (16H, m, Hq, Hq0), 0.90
3
(6H, 2 · t, Hr, Hr0, JHH = 6.9 Hz).
13C NMR (100.61 MHz, CDCl3): d = 149.6 (j), 149.2
(k), 148.2 (b), 148.0 (a), 133.3 (e), 132.4 (d), 130.8 (g),
129.6 (h), 123.5 (f), 122.6 (c), 120.3 (m), 113.5 (l), 111.4
(i), 69.3 (n), 69.2 (n0), 31.8, 29.4, 29.3, 29.2, 26.0, 22.7
(o, o0, p, p0 q, q0), 14.1 (r, r0).
1H NMR (400 MHz, CD2Cl2): d = 8.36 (1H, s, He),
7.43 (2H, m, Hb), 7.26 (1H, m, Ha), 7.22 (2H, m, Hc),
3
7.17 (2H, s, Hg) 4.08 (4H, t, Hj0, JHH = 6.5 Hz), 4.04
3
(2H, t, Hj, JHH = 6.5 Hz), 1.86 (4H, m, Hk0), 1.77
(2H, m, Hk), 1.44 (52H, m, Hl, Hl0), 0.91 (9H, 2 · t,
3
Hm, Hm0, JHH = 7.0 Hz).
13C NMR (100.61 MHz, CD2Cl2): d = 160.3 (e),
153.8 (h), 152.6 (d), 141.5 (i), 131.79 (f), 129.5 (b),
126.0 (a), 121.1 (c), 107.2 (g), 73.8 (j), 69.5 (j0), 32.3,
30.8, 30.2, 30.1, 30.1, 30.0, 29.8, 29.7, 26.5, 23.1 (k, k0,
l, l0), 14.3 (m, m).
n' o' p' q' r'
c
d
OCH2CH2CH2(CH2)4CH3
i
j
f
b
e
h
N
OCH2CH2CH2(CH2)4CH3
k
g
a
n
o
p
q
r
m l
(8)
4.4. Preparation of 3,4,5-trialkoxy-30-stilbazole (9) and
3,4,5-trialkoxy-20-stilbazole (10)
1H NMR (400 MHz, CDCl3): d = 8.59 (1H, dd, Ha,
The preparation of 3,4,5-tridodecyloxy-30-stilbazole
will be described; 3,4,5-trioctyloxy-30-stilbazole was
made in the same way. The isomeric 3,4,5-trialkoxy-20-
stilbazoles were made in the same way except that the
3-picoline was replaced with 2-picoline.
4
3JHH = 4.8 Hz, JHH = 1.8 Hz), 7.65 (1H, dt, Hc, 2 ·
4
3JHH = 7.7 Hz, JHH = 1.8 Hz), 7.55 (1H, AB, Hg,
3
JAB = 16.1 Hz), 7.38 (1H, d, Hd, JHH = 7.9 Hz), 7.16
4
(1H, d, Hi, Jm = 1.8 Hz), 7.11 (2H, m, Hb, Hm), 7.04
3,4,5-Tridodecyloxybenzylidene aniline (3.50 g, 4.8
mmol) was dissolved with heating in DMF (30 cm3).
3-Picoline (0.82 g, 8.8 mmol) was added with stirring,
(1H, AB, Hf, JAB = 16.1 Hz), 6.87 (1H, d, Hl,
3
3JHH = 8.3 Hz), 4.05 (2H, t, Hn0, JHH = 6.7 Hz), 4.02
3
(2H, t, Hn, JHH = 6.6 Hz), 1.85 (2H, m, Ho0), 1.83
(2H, m, Ho), 1.49 (4H, m, Hp, Hp0), 1.32 (16H, m,
followed
by
potassium
tert-butoxide
(4.40 g,
3
Hq, Hq0), 0.89 (6H, 2 · t, Hr, Hr0, JHH = 6.9 Hz).
36.0 mmol) in fractions. The solution immediately

320
D.M. Huck et al. / Polyhedron 25 (2006) 307–324
turned dark red. The system was heated to 80 ꢁC and
was stirred for 2.5 h. After cooling HCl solution
(10%) was added dropwise until the pH of the mixture
was neutral. Water (100 cm3) was added and the solu-
tion became yellow. The product was extracted into
DCM (2 · 75 cm3) and was washed with NaHCO3 solu-
tion (200 cm3 saturated) and H2O (200 cm3). The or-
ganic phase was dried over magnesium sulfate and
the DCM was removed. The residue was then taken
into toluene (100 cm3) and was repeatedly with water
(4 · 100 cm3) to remove the DMF. The toluene was
then removed in vacuo to leave a light brown solid.
This was purified by column chromatography on silica
gel. The solvent system was ethyl acetate:hexane, 1:4. A
few drops of triethylamine were added to prevent the
stilbazole sticking to the column. The product was then
crystallised from hot hexane to give a colourless pow-
der (2.59 g, 88%).
l' m' n'
o'
p'
c
d
OCH2CH2CH2(CH2)8CH3
j
i
f
b
e
h
N
OCH2CH2CH2(CH2)8CH3
k
g
a
l
m
n
o
p
j
i
OCH2CH2CH2(CH2)8CH3
l' m' n' o' p'
(10)
1
H NMR (400 MHz, CDCl ): d = 8.59 (1H, dd, Ha,
3
3
3
4
J
J
= 5.0 Hz,
J
= 1.5 Hz), 7.67 (1H, dt, Hc,
HH = 7.6 Hz,
J
HH = 1.5 Hz), 7.52 (1H, AB, Hg,
4
HH
HH
3
J
= 16.0 Hz), 7.41 (1H, d, Hd, J = 7.6 Hz), 7.15
(1H, dd, Hb, J = 7.6 Hz, J =H5H.0 Hz), 7.06 (1H,
AB
3
3
HH
HH
AB, Hf, J = 16.0 Hz), 6.80 (2H, s, Hi), 4.02 (4H, t,
AB
0
3
3
Hl , J = 6.7 Hz), 3.98 (2H, t, Hl, J = 6.8), 1.83
HH
HH
(4H, m, Hm0), 1.76 (2H, m, Hm), 1.48 (6H, m, Hn,
Hn0), 1.27 (40H, m, Ho, Ho0), 0.89 (9H, t, Hp, Hp0,
3
J
= 6.8 Hz).
HH
13C NMR (100.61 MHz, CDCl3): d = 155.6 (e), 153.3
l' m' n'
o'
p'
c
d
a
(j), 149.4 (a), 138.9 (k), 136.7 (c), 133.2 (g), 131.6 (h),
126.6 (f), 121.9 (b), 121.7 (d), 105.7 (i), 73.6 (l), 69.1
(l0), 31.9, 30.3, 29.8, 29.7, 29.6, 29.4, 26.1, 22.7 (m, m0,
n, n0, o, o0), 14.1 (p, p0).
OCH2CH2CH2(CH2)8CH3
j
i
f
b
e
h
N
OCH2CH2CH2(CH2)8CH3
g
k
l
m
n
o
p
j
i
OCH2CH2CH2(CH2)8CH3
l' m' n' o' p'
4.5. Preparation of bis(3,4-dialkoxy-30-stilbazole)-
silver(I) dodecylsulfate (11a) and bis(3,4-dialkoxy-20-
stilbazole)silver(I) dodecylsulfate (12a)
(9)
1H NMR (400 MHz, CDCl3): d = 8.71 (1H, d, Ha,
3
4
4Jm = 1.7 Hz), 8.48 (1H, dd, Hb, JHH = 4.7 Hz, JHH
=
All homologues were made by the same method as
for bis(3,4-dioctyloxy-20-stilbazole)silver(I) dodecylsul-
fate which is described. Bis(3,4-dialkoxy-30-stilbazole)
silver(I) dodecylsulfates were made in the same way.
In a vessel protected from light, silver(I) dodecylsulfate
(97 mg, 0.26 mmol) was stirred as a suspension in DCM
(10 cm3). 3,4-Dioctyloxy-20-stilbazole (250 mg, 0.27
mmol) dissolved in DCM (10 cm3) was added slowly.
The mixture was stirred at room temperature for 4 h. It
was then filtered through celite, to remove any unreacted
silver(I) dodecylsulfate, and the solvent was removed in
vacuo to leave a yellow residue, which was crystallised
from hot acetone and recrystallised from hot methanol
to give a colourless, crystalline solid (199 mg, 62%).
1.7 Hz), 7.82 (1H, dt, Hd, 3JHH = 8.0 Hz, 4JHH = 1.7 Hz),
3
3
7.29 (1H, dd, Hc, JHH = 8.0 Hz, JHH = 4.7 Hz), 7.07
(1H, AB, Hg, JAB = 16.4 Hz), 6.94 (1H, AB, Hf,
JAB = 16.4 Hz), 6.73 (2H, s, Hi), 4.03 (4H, t, Hl0,
3JHH = 6.4 Hz), 3.99 (2H, t, Hl, JHH = 6.6 Hz), 1.84
3
(4H, m, Hm0), 1.76 (2H, m, Hm), 1.48 (6H, m, Hn, Hn0),
3
1.27 (48H, m, Ho, Ho0), 0.87 (9H, t, Hp, Hp0, JHH
=
6.8 Hz).
13C NMR (100.61 MHz, CDCl3): d = 153.4 (j), 148.2
(b), 148.1 (a), 138.7 (e), 133.2 (k), 132.6 (d), 131.8 (h),
131.3 (g), 123.7 (f), 123.6 (c), 105.2 (i), 73.6 (l), 69.2
(l0), 32.0, 31.9, 30.3, 29.8, 29.7, 29.6, 29.4, 26.1, 22.7
(m, m0, n, n0, o, o0), 14.1 (p, p0).
q' p'
o' n'
CH3(CH2)5CH2CH2O
j
i
g
d
a
c
CH3(CH2)5CH2CH2O
k
h
e
b
q
p
o
n
s
t
u
v
m
f
l
N
+Ag
-O3SOCH2CH2(CH2)9CH3
N
OCH2CH2(CH2)5CH3
OCH2CH2(CH2)5CH3
(11a)

D.M. Huck et al. / Polyhedron 25 (2006) 307–324
321
1H NMR (400 MHz, CDCl3): d = 8.92 (2H, d, Ha,
4.6. Preparation of bis(3,4-dialkoxy-30-
stilbazole)silver(I) triflate (11b) and bis(3,4-dialkoxy-
3
4JHH = 1.8 Hz), 8.60 (2H, dd, Hb JHH = 5.5 Hz,
3
4JHH = 1.8 Hz), 7.78 (2H, dt, Hd, JHH = 8.0 Hz,
20-stilbazole)silver(I) triflate (12b)
3
4JHH = 1.8 Hz), 7.29 (2H, dd, Hc, JHH = 5.5 Hz,
3JHH = 8.0 Hz), 7.17 (2H, AB, Hg, JAB = 16.3 Hz),
All homologues were made by the same method as
for bis(3,4-dibutyloxy-30-stilbazole) silver(I) triflate
which is described. Bis(3,4-alkoxy-20-stilbazole) silver(I)
triflate was made in the same way.
4-Dibutyloxy-30-stilbazole (0.300 g, 0.92 mmol) and
silver(I) triflate (0.113 g, 0.044 mmol) were placed in a
flask protected from light. Acetone (5 cm3) was added
and the mixture was stirred at room temperature for
4
7.07 (2H, d, Hi, JHH = 1.8 Hz), 7.03 (2H, dd, Hm,
4
3JHH = 8.4 Hz, JHH = 1.8 Hz), 6.81 (2H, d, Hl,
3JHH = 8.4 Hz), 6.81 (2H, AB, Hf, JAB = 16.3 Hz),
3
4.14 (2H, t, Hs, JHH = 6.9 Hz), 4.04 (4H, t, Hn0,
3
3JHH = 6.6 Hz), 4.02 (4H, t, Hn, JHH = 6.3 Hz), 1.83
(8H, m, Ho, Ho0), 1.65 (2H, m, Ht), 1.54 (58H, m, Hp,
Hp0, Hu), 0.89 (15H, m, Hq, Hq0, Hv).
q' p'
r'
o' n'
CH3(H2C)4CH2CH2CH2O
j
i
g
d
c
CH3(H2C)4CH2CH2CH2O
k
e
h
q
p
o
r
n
b
f
m
l
N
a
-O3SOCH2CH2(CH2)9CH3
Ag+
s
u
v
t
N
OCH2CH2CH2(CH2)4CH3
OCH2CH2CH2(CH2)4CH3
(12a)
1H NMR (400 MHz, CDCl3): d = 8.95 (2H, dd,
4 h. After cooling in ice the colourless precipitate was fil-
tered off and was washed with cold acetone giving a col-
ourless solid of analytical purity (0.350 g, 86%).
3
4
Ha, JHH = 4.5 Hz, JHH = 1.5 Hz), 7.80 (2H, dt,
3
4
Hc, JHH = 7.8 Hz, JHH = 1.5 Hz), 7.66 (2H, d,
q'
p'
o' n'
CH3CH2CH2CH2O
j
i
g
d
c
CH3CH2CH2CH2O
k
h
e
b
q
p
o
n
r
m
f
l
N
-O3SCF3
a
+Ag
N
OCH2CH2CH2CH3
OCH2CH2CH2CH3
(11b)
3
3
Hd, JHH = 8.2 Hz), (2H, dd, Hb, JHH = 7.8 Hz,
3JHH = 4.5 Hz), 7.21 (2H, AB, Hg, JAB = 16.2 Hz),
7.06 (1H, AB, Hf, JAB = 16.2 Hz), 7.88 (2H, d,
1H NMR (400 MHz, CDCl3): d = 8.84 (2H, d, Ha,
3
4JHH = 1.8 Hz), 8.51 (2H, dd, Hb JHH = 5.2 Hz,
3
4JHH = 1.8 Hz), 7.72 (2H, dt, Hd, JHH = 8.1 Hz,
Hi, 4Jm = 1.8 Hz), 6.84 (2H, d, Hm, JHH = 8.2 Hz,
4JHH = 1.8 Hz), 7.24 (2H, dd, Hc, JHH = 5.2 Hz,
3
3
4JHH = 1.8 Hz), 6.68 (2H, d, Hl, JHH = 8.2 Hz),
3JHH = 8.1 Hz), 7.13 (2H, AB, Hg, JAB = 16.4 Hz),
3
3
4
4.09 (2H, t, Hs, JHH = 6.7 Hz), 3.96 (4H, t, Hn0,
7.05 (2H, d, Hi, JHH = 1.8 Hz), 6.99 (2H, d, Hm,
3JHH = 6.7 Hz), 3.79 (4H, t, Hn, JHH = 6.6 Hz),
3JHH = 8.3 Hz, JHH = 1.8 Hz), 6.80 (2H, d, Hl,
3
4
1.80 (4H, m, Ho0), 1.73 (4H, m, Ho), 1.63 (2H,
m, Ht), 1.52 (8H, m, Hp, Hp0), 1.34 (50H, m,
Hq, Hq0, Hu), 089 (15H, 2 · t, Hr, Hr0,
3JHH = 6.6 Hz).
J = 8.3 Hz), 6.74 (2H, AB, Hf, JAB = 16.4 Hz), 4.03
3
(4H, t, Hn0, JHH = 6.6 Hz), 4.02 (4H, t, Hn,
3JHH = 6.6 Hz), 1.83 (8H, m, Ho, Ho0), 1.53 (8H, m,
Hp, Hp0), 1.00 (12H, m, Hq, Hq0).

322
D.M. Huck et al. / Polyhedron 25 (2006) 307–324
q'
p'
r'
o' n'
CH3(H2C)8CH2CH2CH2O
j
i
g
d
c
CH3(H2C)8CH2CH2CH2O
k
e
h
q
p
r
o
n
b
f
m
l
N
a
Ag+
-O3SCF3
s
N
OCH2CH2CH2(CH2)8CH3
OCH2CH2CH2(CH2)8CH3
(12b)
1H NMR (400 MHz, CDCl3): d = 8.95 (2H, dd, Ha,
bazole)silver(I) dodecylsulfates except that the 20-stil-
bazole was replaced by 30-stilbazole.
4
3JHH = 4.5 Hz, JHH = 1.5 Hz), 7.80 (2H, dt, Hc,
4
3JHH = 7.8 Hz, JHH = 1.5 Hz), 7.66 (2H, d, Hd,
In a vessel protected from light, silver(I) dodecylsulfate
(56 mg, 0.15 mmol) was stirred as a suspension in DCM
(10 cm3). 3,4,5-Tridodecyloxy-20-stilbazole (250 mg,
0.14 mmol) dissolved in DCM (10 cm3) was added slowly.
The mixture was stirred at room temperature for 4 h. It
was then filtered over celite, to remove any unreacted sil-
ver(I) dodecylsulfate, and the solvent was removed in va-
cuo to leave a yellow residue. This was crystallised from
hot acetone and recrystallised from hot methanol to give
a colourless crystalline solid (189 mg, 67%).
3JHH = 8.2 Hz), (2H, dd, Hb, 3JHH = 7.8 Hz,
3JHH = 4.5 Hz), 7.21 (2H, AB, Hg, JAB = 16.2 Hz),
7.06 (1H, AB, Hf, JAB = 16.2 Hz), 7.88 (2H, d, Hi,
3
4Jm = 1.8 Hz), 6.84 (2H, d, Hm, JHH = 8.2 Hz,
3
4JHH = 1.8 Hz), 6.68 (2H, d, Hl, JHH = 8.2 Hz), 3.96
3
(4H, t, Hn0, JHH = 6.7 Hz), 3.79 (4H, t, Hn,
3JHH = 6.6), 1.80 (4H, m, Ho0), 1.73 (4H, m, Ho), 1
(8H, m, Hp, Hp0), 1.34 (64H, m, Hq, Hq0), 089 (12H,
3
2 · t, Hr, Hr0, JHH = 6.6 Hz).
o'
n'
p'
m' l'
CH3(CH2)8CH2CH2CH2O
j
i
p
o
n
m
l
g
d
c
CH3(CH2)8CH2CH2CH2O
h
k
e
b
q
s
t
r
f
-O3SOCH2CH2(CH2)9CH3
CH3(CH2)8CH2CH2CH2O
N
a
Ag+
N
OCH2CH2CH2(CH2)8CH3
OCH2CH2CH2(CH2)8CH3
OCH2CH2CH2(CH2)8CH3
(13a)
4.7. Preparation of bis(3,4,5-trialkoxy-30-stilbazole)-
silver(I) dodecylsulfate (13a) and bis(3,4,5-trialkoxy-20-
stilbazole)silver(I) dodecylsulfate (14a)
1H NMR (200 MHz, CDCl3): d = 8.90 (2H, d,
Ha,
4JHH = 1.6 Hz),
8.59
(2H,
dd,
Hb
4
3JHH = 5.1 Hz, JHH = 2.0 Hz), 7.82 (2H, dt, Hd,
3JHH = 8.07 Hz, JHH = 2.0 Hz), 7.29 (2H, dd, Hc,
4
3
The preparation of bis(3,4,5-dodecyloxy-20-stilbaz-
ole)silver(I) dodecylsulfate is described and the octyloxy
homologue was made in the same way. Bis(3,4,5-alkoxy-
30-stilbazole)silver(I) dodecylsulfates were prepared in
the same way as is described for bis(3,4,5-alkoxy-20-stil-
3JHH = 5.1 Hz, JHH = 8.0 Hz), 7.16 (2H, AB, Hg,
JAB = 16.3 Hz), 6.90 (2H, AB, Hf, JAB = 16.3 Hz),
3
6.74 (4H, s, Hi), 4.09 (2H, t, Hq, JHH = 6.77 Hz),
3
4.06 (8H, t, Hl0, JHH = 6.8 Hz), 3.99 (4H, t, Hl,
3JHH = 6.8 Hz), 1.80 (14H, m, Hm, Hm0, Hr), 1.36

D.M. Huck et al. / Polyhedron 25 (2006) 307–324
323
o'
n'
p'
m' l'
CH3(CH2)8CH2CH2CH2O
j
i
g
d
c
CH3(CH2)8CH2CH2CH2O
k
e
h
p
o
n
m
l
b
f
CH3(CH2)8CH2CH2CH2O
N
q
s
t
a
r
-O3SOCH2CH2(CH2)9CH3
Ag+
N
OCH2CH2CH2(CH2)8CH3
OCH2CH2CH2(CH2)8CH3
OCH2CH2CH2(CH2)8CH3
(14a)
(126H, m, Hn, Hn0, Ho, Ho0, Hs), 0.88 (21H, m,
Hp, Hp0, Ht).
ver(I) triflate was also prepared in the same way except
that the 30-stilbazole was replaced by 20-stilbazole.
3,4,5-Tridodecyloxy-30-stilbazole (200 mg, 0.27 mmol)
and silver(I) triflate (20 mg, 0.19 mmol) were placed in a
flask protected from light. Acetone (5 cm3) was added
and the mixture was stirred at room temperature for
4 h. The mixture was then cooled in ice before being
1H NMR (400 MHz, CDCl3): d = 8.97 (2H, dd, Ha,
4
3JHH = 4.8 Hz, JHH = 1.5 Hz), 7.82 (2H, dt, Hc,
4
3JHH = 7.7 Hz, JHH = 1.5 Hz), 7.65 (2H, d, Hd,
3
3JHH = 7.7 Hz), 7.33 (2H, dd, Hb, JHH = 4.8 Hz,
3JHH = 7.7 Hz), 7.16 (2H, AB, Hg, JAB = 15.8 Hz),
o'
n'
p'
m' l'
CH3(H2C)8CH2CH2CH2O
j
i
p
o
n
m
l
g
d
c
CH3(H2C)8CH2CH2CH2O
h
k
e
b
f
q
CH3(H2C)8CH2CH2CH2O
N
Ag+
a
-O3SCF3
N
OCH2CH2CH2(CH2)8CH3
OCH2CH2CH2(CH2)8CH3
OCH2CH2CH2(CH2)8CH3
(13b)
7.06 (2H, AB, Hf, JAB = 15.8 Hz), 6.44 (4H, s, Hi),
filtered and washed with cold acetone giving a colourless
solid (190 mg, 84%).
3
4.11 (2H, t, Hq, JHH = 6.7 Hz), 3.92 (4H, t, Hl,
3
3JHH = 6.6 Hz), 3.76 (8H, t, Hl0 JHH = 6.0), 1.69
1H NMR (400 MHz, CDCl3): d = 8.87 (2H, d, Ha,
3
(12H, m, Hm0, Hm), 1.34 (128H, m, Hn, Hn0, Ho, Ho0,
4JHH = 1.6 Hz), 8.50 (2H, dd, Hb JHH = 5.2 Hz,
3
3
Hr, Hs), 0.89 (21H, 2 · t, Hr, Hr0, Ht, JHH = 6.4 Hz).
4JHH = 1.8 Hz), 7.82 (2H, dt, Hd, JHH = 8.1 Hz,
4JHH = 1.6 Hz), 7.29 (2H, dd, Hc, 3JHH = 5.2
3
4.8.Preparationofbis(3,4,5-trialkoxy-30-stilbazole)silver-
(I) triflate (13b) and bis(3,4,5-trialkoxy-20-stilbazole)-
silver(I) triflate (14b)
Hz, JHH = 8.1 Hz), 7.14 (2H, AB, Hg, JAB = 16.4 Hz),
6.81 (2H, AB, Hf, JAB = 16.4 Hz), 6.73 (4H, s, Hi), 4.01
3
(8H, t, Hl0, JHH = 6.3 Hz), 3.98 (4H, t, Hl,
3JHH = 6.7 Hz), 1.79 (12H, m, Hm, Hm0), 1.36 (108H,
m, Hn, Hn0, Ho, Ho0), 0.88 (18H, m, Hp, Hp0).
1H NMR (400 MHz, CDCl3): d = 8.91 (2H, dd, Ha,
Bis(3,4,5-tridodecyloxy-30-stilbazole)silver(I) triflate
is described and the other homologues were prepared
in the same way. Bis(3,4,5-dodecyloxy-20-stilbazole)sil-
4
3JHH = 5.1 Hz, JHH = 1.5 Hz), 7.85 (2H, dt, Hc,

324
D.M. Huck et al. / Polyhedron 25 (2006) 307–324
o'
n'
p'
m' l'
CH3(CH2)8CH2CH2CH2O
j
i
g
d
c
CH3(CH2)8CH2CH2CH2O
k
e
h
p
o
n
m
l
b
f
CH3(CH2)8CH2CH2CH2O
N
a
q
Ag+
-O3SCF3
OCH2CH2CH2(CH2)8CH3
N
OCH2CH2CH2(CH2)8CH3
OCH2CH2CH2(CH2)8CH3
(14b)
4
3JHH = 7.7 Hz, JHH = 1.46 Hz), 7.66 (2H, d, Hd,
[4] H.L. Nguyen, P.N. Horton, M.B. Hursthouse, A.C. Legon,
D.W. Bruce, J. Am. Chem. Soc. 126 (2004) 16.
[5] D.W. Bruce, Adv. Inorg. Chem. 52 (2001) 151.
[6] B. Donnio, D.W. Bruce, J. Chem. Soc., Dalton Trans. (1997)
2745.
[7] D.W. Bruce, Acc. Chem. Res. 33 (2000) 831.
[8] C. Mongin, B. Donnio, D.W. Bruce, J. Am Chem. Soc. 123 (2001)
8426.
3JHH = 7.7 Hz), 7.36 (2H, dd, Hb, JHH = 5.1 Hz,
3
3JHH = 7.7 Hz), 7.15 (2H, AB, Hg, JAB = 16.2 Hz),
7.08 (2H, AB, Hf, JAB = 16.2 Hz), 6.41 (4H, s, Hi),
3
3.91 (4H, t, Hl, JHH = 6.5 Hz), 3.73 (8H, t, Hl0,
3JHH = 6.4), 1.86 (12H, m, Hm0, Hm), 1.30 (108H, m,
Hn, Hn0, Ho, Ho0), 0.81 (18H, 2 · t, Hr, Hr0, Ht,
3JHH = 6.4 Hz).
[9] D. Fazio, C. Mongin, B. Donnio, Y. Galerne, D. Guillon, D.W.
Bruce, J. Mater. Chem. 11 (2001) 2852.
[10] D.M. Huck, H.L. Nguyen, S.J. Coles, M.B. Hursthouse, B.
Donnio, D.W. Bruce, J. Mater. Chem. 12 (2002) 2879.
[11] J. Maltheˆte, H.-T. Nguyen, C. Destrade, Liq. Cryst. 13 (1993)
171.
5. Supplementary material
[12] H.-T. Nguyen, C. Destrade, J. Maltheˆte, Adv. Mater. 9 (1997)
375.
Crystallographic data (excluding structure factors)
for the structures in this paper, has been deposited with
the Cambridge Crystallographic Data Centre as supple-
mentary publication numbers CCDC 267944, 267945
and 267946. Copies of the data can be obtained, free
of charge, on application to CCDC, 12 Union Road,
Cambridge CB2 1EZ, UK (Fax: +44(0) 1223 336033
or e-mail: deposit@ccdc.cam.ac.uk).
[13] B. Donnio, D.W. Bruce, B. Heinrich, D. Guillon, H. Delacroix,
T. Gulik-Krzywicki, Chem. Mater. 9 (1997) 2951.
[14] B. Donnio, D.W. Bruce, New J. Chem. 23 (1999) 275.
[15] (a) C.B. Ziegler Jr., R.F. Heck, J. Org. Chem. 43 (1978) 2941;
(b) W.C. Frank, Y.C. Kim, R.F. Heck, J. Org. Chem. 43 (1978)
2947;
(c) C.B. Ziegler Jr., R.F. Heck, J. Org. Chem. 43 (1978) 2949;
(d) N.A. Cortese, C.B. Ziegler Jr., R.F. Heck, J. Org. Chem. 43
(1978) 2952.
[16] A.E. Siegrist, Helv. Chim. Acta 50 (1967) 906.
[17] H. Meier, Angew. Chem. Int. Ed. Engl. 31 (1992) 1399.
[18] D.M. Huck, H.L. Nguyen, B. Donnio, D.W. Bruce, Liq. Cryst.
31 (2004) 503.
Acknowledgements
[19] J.F. Eckert, U. Maciejczuk, D. Guillon, J.F. Nierengarten, Chem.
Commun. (2001) 1278.
[20] H. Adams, N.A. Bailey, D.W. Bruce, D.A. Dunmur, S.C. Davies,
P.M. Maitlis, P.D. Hempstead, S.A. Hudson, S.J. Thorpe, J.
Mater. Chem. 2 (1992) 395.
`
We thank the EPSRC and the College Doctoral Eur-
´
opeen de Strasbourg for support.
[21] H. Gallardo, R. Magnaco, A.J. Bortoluzzi, Liq. Cryst. 28 (2001)
1343.
References
[22] B. Donnio, B. Heinrich, H. Allouchi, J. Kain, S. Diele, D.
Guillon, D.W. Bruce, J. Am. Chem. Soc. 126 (2004) 15258.
[23] S. Diele, P. Go¨ring, in: D. Demus, J. Goodby, G.W. Gray, H.-W.
Spiess, V. Vill (Eds.), Handbook of Liquid Crystals, vol. 2B,
Wiley-VCH, Weinheim, 1998 (Chapter XIII).
[1] B. Donnio, D. Guillon, R. Deschenaux, D.W. Bruce, in: J.A.
McCleverty, T.J. Meyer (Eds.), Comprehensive Coordination
Chemistry II, vol. 7, Elsevier, Oxford, UK, 2003, p. 357 (Chapter
7.9).
´
[24] Collect: Data collection software, R. Hooft, Nonius B.V., 1998.
[25] Z. Otwinowski, W. Minor, in: C.W. Carter, R.M. Sweet Jr. (Eds.),
Methods in Enzymology: Macromolecular Crystallography, part
A, vol. 276, Academic Press, New York, 1997, pp. 307–326.
[26] G.M. Sheldrick, Acta Cryst. A46 (1990) 467.
[27] G.M. Sheldrick, University of Go¨ttingen, Germany, 1977.
[2] R. Gimenez, D.P. Lydon, J.L. Serrano, Curr. Opn. Solid State
Mat. Sci. 6 (2002) 527.
[3] (a) See e.g. K. Willis, D.J. Price, H. Adams, G. Ungar, D.W.
Bruce, J. Mater. Chem. 5 (1995) 2195;
(b) D.J. Price, K. Willis, T. Richardson, G. Ungar, D.W. Bruce,
J. Mater. Chem. 7 (1997) 883.