Synthesis, complexation, and E-Z photoisomerization of azadithiacrown- containing styryl dyes as new optical sensors for mercury cations

Article abstract of DOI:10.1007/s11172-007-0082-4

New styryl dyes containing azadithia-15-crown-5 fragments were synthesized. The complexation of these compounds with Ag⁺, Pb²⁺, Cu²⁺, Hg²⁺, and H⁺ cations was studied by ¹H NMR spectroscopy, steady-state, and time-resolved spectroscopy. The stability constants of the complexes were calculated from the spectrophotometric titration data. The photophysical properties and E-Z photoisomerization of styryl dyes and their complexes with mercury and copper(II) cations in acetonitrile were examined.

Full text of DOI:10.1007/s11172-007-0082-4

Russian Chemical Bulletin, International Edition, Vol. 56, No. 3, pp. 513—526, March, 2007
513
Synthesis, complexation, and E—Z photoisomerization of
azadithiacrownꢀcontaining styryl dyes
as new optical sensors for mercury cations
b
b
c
E. V. Tulyakova,a O. A. Fedorova, Yu. V. Fedorov, G. Jonusauskas,
ꢀ
L. G. Kuz´mina,d J. A. K. Howard,e and A. V. Anisimova
aDepartment of Chemistry, M. V. Lomonosov Moscow State University,
1 Leninskie Gory, 119992 Moscow, Russian Federation.
Fax: +7 (495) 932 8568. Eꢀmail: tulyakova@petrol.chem.msu.ru
bPhotochemistry Center, Russian Academy of Sciences,
7A ul. Novatorov, 119421 Moscow, Russian Federation.
Fax: +7 (495) 936 1255. Eꢀmail: fedorova@photonics.ru
cCenter for Molecular, Optical, and Hertzian Physics, University of Bordeaux I,
351 Cours de la Libération, 33405 Talence, France.*
Fax: (33) 540 00 6970. Eꢀmail: g.jonusauskas@cpmoh.uꢀbordeaux1.fr
dN. S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences,
31 Leninsky prosp., 119991 Moscow, Russian Federation.
Eꢀmail: kuzmina@igic.ras.ru
eDepartment of Chemistry, University of Durham,
South Road, Durham DH1 3LE, UK.
Eꢀmail: j.a.k.howard@durham.ac.uk
New styryl dyes containing azadithiaꢀ15ꢀcrownꢀ5 fragments were synthesized. The comꢀ
plexation of these compounds with Ag+, Pb2+, Cu2+, Hg2+, and H+ cations was studied by
1H NMR spectroscopy, steadyꢀstate, and timeꢀresolved spectroscopy. The stability constants
of the complexes were calculated from the spectrophotometric titration data. The photophysical
properties and E—Z photoisomerization of styryl dyes and their complexes with mercury and
copper(II) cations in acetonitrile were examined.
Key words: styryl dyes, phenylazadithiaꢀ15ꢀcrownꢀ5 ether, complexation, photochemistry,
E—Z photoisomerization.
A considerable progress in chemistry of macrocyclic
compounds is associated not only with their fundamental
importance but also with their practical applications in
organic synthesis, biology, medicine, and industry.1—5
Macroheterocyclic sulfurꢀcontaining compounds (crown
compounds, cryptands, catenanes, rotaxanes, and cycloꢀ
phanes) have attracted great interest6—11 because of their
ability to selectively form stable complexes with transition
and heavy metal cations. These compounds are of considꢀ
erable interest as byꢀproducts in the synthesis of polymers
containing thiacrown groups, selective chromogenic and
photochromic reagents for metal cations, and extractants
for metal salts.
The aim of the present study was to synthesize deꢀ
rivatives of azathiacrown ethers having affinity for heavy
and transition metal cations, investigate the complexꢀ
ation of metal cations with different heteroatoms of
the macrocycle, and reveal the influence of complexꢀ
ation on the optical and photochemical characterisꢀ
tics of these compounds. Studies of azacrownꢀcontainꢀ
ing styryl dyes demonstrated12,13 that complexation
with rareꢀearth metal cations leads to shifts in absorpꢀ
tion spectra as large as 50—70 nm. On the one hand,
the compounds synthesized and investigated in the
present study contain the ionophoric fragment of the
phenylazacrown macrocycle, which gives promise that
the complexation with metal cations will result in a large
optical response. On the other hand, the introduction of
sulfur atoms into the macrocycle makes it possible to
achieve selective binding with metal salts, which is of
* Centre de Physique Moléculaire Optique et Hertzienne —
UMR CNRS 5798, Bordeaux University I, 351 Cours de la
Libération, 33405 Talence, France.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 495—507, March, 2007.
1066ꢀ5285/07/5603ꢀ0513 © 2007 Springer Science+Business Media, Inc.

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Tulyakova et al.
importance for the development of the industrial cation
analysis.
dependent molecules A and B and the atomic numbering
scheme are presented in Fig. 1. Selected bond lengths and
bond angles are given in Table 1.
Results and Discussion
Slight random differences in the bond lengths involvꢀ
ing the S atoms are, apparently, attributed to thermal
motion of these atoms and are associated with a high
flexibility of the macrocycle, particularly, in the vicinity
of the S atoms. In addition to higher anisotropic temperaꢀ
ture factors of the S atoms compared to those of most of
C atoms, this is also evidenced by the presence of two
crystallographically independent molecules containing the
macrocycles in different conformations. The existence of
two crystallographically independent molecules has been
observed earlier10 for the tricyanovinyl derivative of
phenylazadithiaꢀ15ꢀcrownꢀ5 ether.
The bonds at the N atom have a planarꢀtrigonal conꢀ
figuration (the sums of the bond angles at this atom in two
independent molecules are 359.7 and 359.8°). The plane
passing through these bonds is almost coplanar to the
plane of the benzene ring (the dihedral angles are 9.3
and 4.7°). This is indicative of the presence of conjugaꢀ
tion between the lone electron pair of the N atom and the
benzene ring. This conjugation is evidenced by a noticeꢀ
able perturbation of the bond lengths in the benzene
ring. Actually, the C(12)—C(13) (in both molecules,
1.382(5) Å) and C(15)—C(16) (1.375(5) and 1.374(5) Å)
bonds are substantially shorter than the other bonds in the
benzene ring (1.393(6)—1.416(5) Å), which corresponds
to the contribution of the paraꢀquinoid structure. It should
be noted that the analogous distortion of the geometry of
the benzene ring is observed in all benzoazacrown ethers.
Complexation. To estimate the complexation ability of
the resulting compounds, we analyzed the 1H NMR specꢀ
tra of the formyl derivative of phenylazadithiacrown comꢀ
pound 3 in the presence of heavy and transition metal
Synthesis and structure determination. The synthesis
pathway of styryl dyes containing the azadithiaꢀ15ꢀ
crownꢀ5 fragment is presented in Scheme 1. Earlier, it has
been reported that compound 3 can be synthesized by
Vilsmeier formylation of unsubstituted phenylazadithiaꢀ
15ꢀcrownꢀ5 ether. In the present study, we developed an
alternative procedure based on condensation of linear preꢀ
cursors, one of which already contains the formyl group.
This procedure makes it possible to circumvent the partial
opening of the macrocycle and the formation of a podand,
which is generated as a byꢀproduct in direct formylation
of phenylazadithiaꢀ15ꢀcrownꢀ5 ether. The starting comꢀ
pound, viz., pꢀdi(2ꢀchloroethyl)aminobenzaldehyde (2),
involved in the synthesis of the crown ether, was prepared
by the reaction of N,Nꢀdi(2ꢀhydroxyethyl)aniline with
POCl3 followed by Vilsmeier formylation of the resulting
N,Nꢀdi(2ꢀchloroethyl)aniline (1).14 Condensation of alꢀ
dehyde 2 with the corresponding dithiol in the presence
of cesium carbonate in an EtOH—H2O medium afꢀ
forded the formyl derivative of phenylazathiacrown comꢀ
pound 3.15 The reaction of the latter with quaternary
benzothiazolium salts16 in anhydrous ethanol in the presꢀ
ence of pyridine as a catalyst produced crownꢀcontaining
styryl dyes Eꢀ4 and Eꢀ5 (see Scheme 1).
The fact that compounds 4 and 5 exist as E isomers is
1
evidenced by the H NMR spectroscopic data (the spinꢀ
spin coupling constants of the protons of the vinylene
fragment 3JE = 15.2 and 15.6 Hz, respectively).
The structure of compound 3 was established by Xꢀray
diffraction. The structures of two crystallographically inꢀ
Scheme 1
R = Et(ClO4–) (4), (CH2)4SO3– (5)

Phenylazathiacrownꢀcontaining styryl dyes
Russ.Chem.Bull., Int.Ed., Vol. 56, No. 3, March, 2007
515
C(8)
S(2)
S(3)
C(7)
O(2)
C(3´)
C(9)
C(12´)
C(13´)
C(2´)
C(6)
C(5)
C(10)
C(1´)
C(11´)
C(14´)
C(4´)
O(1´)
C(17´)
O(3´)
C(16)
N(1)
C(1)
C(11)
C(15)
C(17)
O(3)
N(1´)
C(15´)
O(1)
C(4)
C(5´)
C(6´)
C(10´)
C(16´)
C(12)
C(14)
C(2)
O(2´)
C(13)
C(9´)
S(4)
C(3)
S(1)
C(7´)
C(8´)
Fig. 1. Structures of two crystallographically independent molecules of compound 3. The corresponding atoms, except for the
S atoms, in molecules A and B are numbered in the same way, but the atoms in molecules B are primed.
perchlorates (Table 2). The addition of Zn2+ ions has no
effect on the positions of the proton signals in the specꢀ
trum of compound 3; the addition of Cd2+ ions leads only
to slight changes in the spectrum, which is indicative of
low stability of the resulting complexes. The addition of
Ag+ or Hg2+ perchlorates to an acetonitrile solution of
compound 3 causes substantial changes in the positions of
those for the methylene groups bound to the O atoms.
The observed effects can be attributed to the fact that
Ag+ cations have a high affinity for S atoms, whereas
Pb2+ cations are equally well coordinated by S and
O atoms. For all the metal cations under consideration,
the smallest ∆δ were observed for the α,α´ꢀCH2N proꢀ
tons. In this case, the metal cations are most weakly coorꢀ
dinated by the N atom, which may be a consequence of
the involvement of the free electron pair of the N atom in
conjugation with the benzene ring. The changes in ∆δ
for the methylene protons were also studied in the presꢀ
ence of HClO4. The addition of HClO4 leads to protonaꢀ
tion of the N atom, which is manifested primarily in the
1
the signals for all protons in the H NMR spectrum. The
largest changes are observed for the chemical shifts of the
methylene protons of the macrocyclic fragment bound to
the S atoms. For the complexes with Pb2+ perchlorate,
the changes in the chemical shifts of the protons (∆δ) of
the methylene groups bound to the S atoms are similar to
Table 1. Selected bond lengths (d) and bond angles (ω) in molecules A and B of compound 3
Bond
A
B
Bond
A
B
d/Å
d/Å
S(1)[S(3)]—C(2)
S(1)[S(3)]—C(3)
S(2)[S(3)]—C(8)
S(2)[S(3)]—C(9)
O(1)—C(4)
O(1)—C(5)
O(2)—C(6)
O(2)—C(7)
N(1)—C(1)
1.814(4)
1.815(4)
1.809(4)
1.803(4)
1.429(5)
1.427(4)
1.420(5)
1.420(6)
1.469(5)
1.841(5)
1.807(4)
1.811(4)
1.805(4)
1.425(5)
1.418(4)
1.422(5)
1.418(5)
1.466(5)
N(1)—C(10)
N(1)—C(11)
C(11)—C(12)
C(11)—C(16)
C(12)—C(13)
C(13)—C(14)
C(14)—C(15)
C(15)—C(16)
C(14)—C(17)
1.461(5)
1.364(4)
1.415(5)
1.423(5)
1.382(5)
1.400(5)
1.397(6)
1.375(5)
1.459(5)
1.452(5)
1.380(5)
1.415(5)
1.416(5)
1.382(5)
1.398(6)
1.393(6)
1.374(5)
1.460(5)
Angle
ω/deg
Angle
ω/deg
C(2)—S(1)[S(3)]—C(3)
C(8)—S(2)[S(3)]—C(9)
C(4)—O(1)—C(5)
C(6)—O(2)—C(7)
C(1)—N(1)—C(10)
103.6(2)
105.6(2)
110.7(3)
112.3(3)
117.0(3)
101.9(2)
104.5(2)
110.4(3)
111.9(3)
117.6(3)
C(1)—N(1)—C(11)
C(10)—N(1)—C(11)
C(12)—C(11)—C(16)
C(13)—C(14)—C(15)
120.9(3)
121.8(3)
117.9(3)
118.0(3)
121.3(3)
120.9(3)
117.3(3)
117.6(3)

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Tulyakova et al.
Table 2. Changes in the proton chemical shifts (∆δ = δ
azadithiacrown group of compound 3 upon complexation*
– δ ) for the phenylꢀ
L
compl
Cation
Мn+
∆δ
2,9ꢀCH2S 3,8ꢀCH2O 5,6ꢀCH2O
12,14ꢀCH2N
11,15ꢀCH2S
Cd2+
Pb2+
Ag+
Hg2+
H+
0.02
0.01
–0.02–
0.04
0.03
0.31
0.20
0.37
–0.08
0.04
0.28
0.19
0.44
0.18
0.02
0.17
0.05
0.02
0.00
0.03
0.14
0.05
0.07
0.13
0.31
* The conditions: CD3CN at 20 °C, CL = 4.68•10–2 mol L–1, and CMn+ = 4.68•10–2 mol L–1
.
changes in the positions of the signals for the α,α´ꢀCH2N
protons.
bathochromic shift of the longꢀwavelength absorption
band (by 5 nm) and a slight increase in the absorbance
(εmax = 6.46•104 L mol–1 cm–1).
The electronic absorption spectrum of dye Eꢀ4 in
MeCN shows an intense longꢀwavelength absorption band
with a maximum at 523 nm (19120 cm–1); the extinction
coefficient εmax = 7.00•104 L mol–1 cm–1 (Fig. 2, curve 1).
The maximum of the longꢀwavelength absorption band
of betaine dye Eꢀ5 is characterized by λ = 521 nm
(19010 cm–1) and εmax = 6.41•104 L mol–1 cm–1 (Fig. 3,
curve 1). In compound Eꢀ5, there is an electrostatic inꢀ
teraction between the negatively charged sulfonate group
and the positively charged N atom of the heterocyclic
moiety of the molecule, resulting in partial disruption of
conjugation, which is responsible for a decrease in the
extinction coefficient compared to that of dye Eꢀ4 and a
small shift in the maximum of the longꢀwavelength abꢀ
sorption band to higher energies. In the presence of
Mg2+ cations, which interact with the sulfonate group of
the dye and eliminate the aboveꢀmentioned electrostatic
interaction, the spectrum of compound Eꢀ5 shows a small
The position of the maximum of the longꢀwavelength
absorption band in the spectra of compounds Eꢀ4 and
Eꢀ5 depends on the nature of the solvent (Table 3).
An increase in the polarity of the solvent in the series
PrnOH, EtOH, MeOH, and H2O is accompanied by a
small hypsochromic shift of the longꢀwavelength absorpꢀ
tion band of Eꢀ4 and Eꢀ5 (the negative solvatochromic
effect). However, by contrast to less polar ethyl acetate,
the solvatochromic effect is not observed in more polar
ethanol, which is apparently indicative of the influence of
the specific effects of the solvents (in particular, possible
hydrogen bonding in protic solvents) on the absorption
spectra of Eꢀ4 and Eꢀ5.
The addition of Pb2+, Hg2+, Ag+, or Cu2+ perchlorꢀ
ates to solutions of Eꢀ4 and Eꢀ5 causes hypsochromic
shifts of the longꢀwavelength absorption band due to comꢀ
plexation at the crown fragment of the molecules (Figs 2
and 3, Table 4). It is known12,18 that the introduction of a
metal cation into the cavity of the crown fragment of
36 32
28
24
20
ν•103/cm–1
A
1
36 32
28
24
20
ν•103/cm–1
1.5
A
4
1.5
1
2
3
1.0
0.5
2
1.0
0.5
6
5
3
4
300
400
500
600 λ/nm
300
400
500
600
λ/nm
Fig. 2. Absorption spectra of Eꢀ4 at a concentration of 2.5•10–5
mol L–1 (1) and in the presence of Pb(ClO4)2 (4.06•10–2
mol L–1) (2), AgClO4 (2.58•10–2 mol L–1) (3), Cu(ClO4)2
(1.90•10–4 mol L–1) (4), Hg(ClO4)2 (2.75•10–5 mol L–1) (5),
or HClO4 (2.78•10–3 mol L–1) (6) in MeCN at 293 K.
Fig. 3. Absorption spectra of Eꢀ5 at a concentration of 2.5•10–5
mol L–1 (1) and in the presence of Pb(ClO4)2 (2.20•10–2
mol L–1) (2), Cu(ClO4)2 (1.16•10–4 mol L–1) (3), or Hg(ClO4)2
(2.75•10–5 mol L–1) (4) in MeCN at 293 K.

Phenylazathiacrownꢀcontaining styryl dyes
Russ.Chem.Bull., Int.Ed., Vol. 56, No. 3, March, 2007
517
ation with Ag+ or Pb2+ may be a consequence of the fact
that Ag+ cations are predominantly coordinated by
S atoms, whereas Pb2+ cations are coordinated by the
O atoms of the azadithiacrown group, resulting in slight
spectral shifts due to small conformational rearrangements
of the dye molecules. This was demonstrated above by
NMR experiments. In this case, the involvement of the
N atom in complexation is, apparently, insignificant. On
the contrary, large hypsochromic shifts of the longꢀwaveꢀ
length absorption band upon complexation of Cu2+ and
Hg2+ are indicative of the involvement of the N atom of
the crown fragment in coordination to these cations
(Scheme 2).
Table 3. Influence of the nature of the solvent on the absorption
spectra of Eꢀ4 and Eꢀ5
Solvent
λ )
max/nm (ε •104/L mol–1 cm–1
max
Eꢀ4
Eꢀ5
EtOAc
(CH2)2(OMe)2
CH2Cl2
Me2CO
MeCN
DMSO
(СH2)3CO
H2O
MeOH
EtOH
529 (6.61)
534 (6.82)
546 (9.25)
524 (8.15)
523 (7.00)
526 (6.44)
526 (6.10)
505 (4.86)
525 (6.31)
529 (5.57)
528 (5.08)
533 (6.33)
535 (5.92)
538 (5.78)
530 (6.32)
534 (5.50)
543 (8.30)
525 (6.24)
521 (6.41)
526 (4.72)
525 (6.07)
510 (5.68)
526 (7.27)
530 (7.15)
529 (5.27)
531 (6.76)
533 (7.00)
535 (7.36)
Scheme 2
(СH2)2(OH)2
PrnOH
nꢀC5H11OH
nꢀC10H21OH
crownꢀcontaining styryl dyes hinders the charge transfer
from the crown ether to the heterocyclic moiety, which
leads to hypsochromic shifts of the longꢀwavelength abꢀ
sorption band.
The hypsochromic shifts of the longꢀwavelength abꢀ
sorption band for Eꢀ4 and Eꢀ5 upon complexation in
MeCN are given in Table 4. The metal cations under
study can be divided into two groups. In the presence
of Pb2+ or Ag+, small changes in the position of the
maximum of the longꢀwavelength absorption band
(by 6—26 nm) were observed. The addition of Cu2+ or
Hg2+ cations leads to a shift of the maximum of the longꢀ
wavelength absorption band by 92—140 nm. Small shifts
of the longꢀwavelength absorption band upon complexꢀ
The stability constants of the complexes of Eꢀ4 and
Eꢀ5 with metal cations were evaluated with the use of
spectrophotometric titration and the HYPERQUAD calꢀ
culation program.19 In the calculations, different pathꢀ
ways of the formation of the complexes were taken into
account (Scheme 3).
The calculated stability constants are given in Table 4.
The direct spectrophotometric determination of the staꢀ
bility constants of the complexes of dyes Eꢀ4 and Eꢀ5
with Hg2+ cations appeared to be impossible because of
Table 4. UV—Vis data and the stability constants of dyes Eꢀ4 and Eꢀ5 and their complexes with lead, silver,
mercury, and copper perchlorate and perchloric acid at 293 K
Complex Cation radius (according
Ionic strength
/mol L–1
λ
max/nm
Stability constant
of the complex
to Shannon17)/Å
(∆λ*/nm)
Eꢀ4 + Pb2+
Eꢀ4 + Ag+
Eꢀ4 + Cu2+
1.33
1.29
0.87
0—8.29•10–2
0—4.46•10–2
0—1.24•10–3
507 (16)
495 (28)
438 (sh),
461 (62)
363 (160)
388 (135)
515 (6)
logK11 = 1.78 0.01
logK11 = 2.63 0.01
logK11 = 5.50 0.10
Eꢀ4 + H+
Eꢀ4 + Hg2+
Eꢀ5 + Pb2+
—
1.16
1.33
0—4.95•10–3
0—1.58•10–4
0—4.87•10–2
logK11 = 4.26 0.02
logK11 = 14.8 0.10
logK12 = 11.82 0.17
logK13 = 18.16 0.26
logK11 = 5.81 0.12
logK21 = 7.49 0.12
logK > 7
Eꢀ5 + Cu2+
Eꢀ5 + Hg2+
0.87
1.16
0—3.67•10–4
0—1.32•10–4
463 (58)
391, 470 (sh)
(130)
logK11 = 19.3 0.2
* ∆λ = (λmax)L – (λ
)
.
max compl

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Russ.Chem.Bull., Int.Ed., Vol. 56, No. 3, March, 2007
Tulyakova et al.
ν•103/cm–1
Scheme 3
36 32
28
24
20
A
Mn+ + L
[ML]n+
1.5
Mn+ + 2 L
Mn+ + 3 L
2 Mn+ + L
2 Mn+ + 2 L
[ML2]n+
1.0
0.5
[ML3]n+
[M2L]2n+
300
400
500
600 λ/nm
[M2L2]2n+
Fig. 5. Spectrophotometric titration of Eꢀ5 by copper(II) perꢀ
chlorate in MeCN (CL = 3.0•10–5 mol L–1); the additives of
copper(II) 0 ≤ xM/L ≤ 3.8.
their very high values. Hence, the corresponding stability
constants were determined by titration with a solution of
a competitive ligand, for which the stability constant of
the complex with the Hg2+ cation is known from the
literature data.20 The complex of dye Eꢀ4 with Hg2+ was
titrated with a styryl dye containing the benzodithiaꢀ15ꢀ
crownꢀ5 group; the complex of Eꢀ5 with Hg2+, with
benzodithiaꢀ18ꢀcrownꢀ6 ether.
with thio esters,21—23 the two lowestꢀenergy bands can be
assigned to d—d* transitions of CuII.
Complexation with lead(II) cations. The complexation
of compound Eꢀ4 with Pb2+ cations is characterized by a
low stability constant and is accompanied by small specꢀ
tral changes. The dependence of the absorption spectrum
of Eꢀ5 on the concentration of Pb2+ cations is presented
in Fig. 6, a. As opposed to compound Eꢀ4, substantial
changes in the spectrum of Eꢀ5 are observed already in
the presence of Pb2+ cations at low concentrations and
are different in character. At CPb2+/CEꢀ5 = 0.5, the maxiꢀ
mum is hypsochromically shifted, which is accompanied
by an increase in the absorbance at the longꢀwavelength
edge of the spectrum. At high Pb2+ concentrations, the
absorption spectral pattern of the [(Eꢀ5)(Pb2+)] complex
is similar to that of the [(Eꢀ4)(Pb2+)] complex. However,
the shift of the longꢀwavelength absorption band is only
6 nm, whereas the shift of the longꢀwavelength absorption
band for [(Eꢀ4)(Pb2+)] is 16 nm.
Complexation with copper(II) cations. The addition of
Cu2+ cations to Eꢀ4 (Fig. 4) results in the disappearance
of the longꢀwavelength absorption band with a maximum
at 521 nm (19190 cm–1) and the appearance of the abꢀ
sorption band with a maximum at 461 nm (21690 cm–1
,
ε ≈ꢁ 4.66•104 L mol–1 cm–1), a shoulder at 438 nm
(22830 cm–1, ε ≈ 4.00•104 L mol–1 cm–1), and two new
absorption bands with maxima at 777 (12870 cm–1, ε ≈
8.57•102 L mol–1 cm–1) and 862 nm (11600 cm–1, ε ≈
1.08•103 L mol–1 cm–1). An analogous situation was obꢀ
served for Eꢀ5 (Fig. 5). According to the published data
on the electronic absorption spectra of CuII complexes
36 32
28
24
20
ν•103/cm–1
As can be seen from the dependence of the fluoreꢀ
scence spectra of Eꢀ5 on the Pb2+ concentration
(Fig. 6, b), an increase in the cation concentration iniꢀ
tially causes a decrease in the intensity of the fluorescence
band, the position of the maximum remaining unchanged,
and then the intensity increases, which is accompanied by
a slight shift of the maximum to shorter wavelengths.
Earlier,12 a similar behavior has been observed for betaine
dyes containing the phenylazaꢀ15ꢀcrownꢀ5 group in the
presence of a small amount of Ca2+ cations, which was
attributed to aggregation of the dye molecules. In this
case, a decrease in the intensity of the fluorescence band
and a sharp decrease in the quantum yield of Eꢀ5 in the
presence of small amounts of Pb2+ cations (Table 5) are
also characteristic of aggregation of Eꢀ5 in solution.
Actually, betaine dye molecules contain two possible
coordination sites of Pb2+ cations, viz., the crown fragꢀ
A
2.0
1.5
1.0
0.5
300
400
500
600 λ/nm
Fig. 4. Spectrophotometric titration of Eꢀ4 by copper(II) perꢀ
chlorate in MeCN (CL = 3.5•10–5 mol L–1); the additives of
copper(II) 0 ≤ xM/L ≤ 5.4.

Phenylazathiacrownꢀcontaining styryl dyes
Russ.Chem.Bull., Int.Ed., Vol. 56, No. 3, March, 2007
519
28 26 24
22
20
18
ν•103/cm–1
crown fragment is low. Hence, the sulfonate group can
serve as a preferred binding site of Pb2+ cations compared
to the crown fragment. According to the calculations of
the complexation constants from the spectrophotometric
titration data (see Table 4), the formation of aggregates,
in which two or three betaine dye molecules are coordiꢀ
nated to the Pb2+ cation apparently with the involvement
of the sulfonate group, is possible at low Pb2+ concentraꢀ
tions. An increase in the Pb2+ concentration leads to a
shift of the equilibrium toward complexes containing one
dye molecule. The interaction between the Pb2+ cation
and the sulfonate group in the complex of compound Eꢀ5
is confirmed by the fact that the position of the maximum
of the fluorescence band remains unchanged in the presꢀ
ence of small amounts of Pb2+. A further increase in the
Pb2+ concentration in solution leads to the formation of
complexes, in which the Pb2+ ion is bound to the azaꢀ
thiacrown fragment of molecule Eꢀ5, and the position of
the maximum of the fluorescence band is shifted to shorter
wavelengths by 8 nm (Scheme 4).
A
1.5
1
2
3
a
4
5
1.0
0.5
6
7
400
450
500
550
600
λ/nm
I (rel. units)
19
18
17
16
15
ν•103/cm–1
1
7
6
b
5
2
4
Scheme 4
3
550
600
650
700
λ/nm
Fig. 6. Dependence of the absorption spectra (a) and fluoreꢀ
scence spectra (b) of Eꢀ5 on the concentration of Pb2+ ions:
CPb2+/CEꢀ5 = 0 (1), 0.12 (2), 0.25 (3), 0.94 (4), 2.62 (5), 41 (6),
and 387 (7); MeCN, 293 K, λexc = 460 nm.
ment and the sulfonate group. The spectrophotometric
titration data for cationic dye Eꢀ4 demonstrated that the
stability constant of the complex with Pb2+ cations for the
n = 1—3
Table 5. Influence of the concentration of lead(II) perchlorate
fl
on the fluorescence quantum yields (ϕ ) of Eꢀ5 (C = 2.27•10–5
Complexation with mercury(II) cations. As opposed to
compound Eꢀ4, the formation of the complex of Eꢀ5 with
Hg2+ cations is accompanied by the appearance of the
absorption band with a maximum at 396 nm, and a longꢀ
wavelength shoulder is observed at 470 nm. The latter
cannot be assigned to residual absorption of the free ligand.
Apparently, two types of complexes, viz., monomeric
[(Eꢀ5)(Hg2+)] and dimeric [(Eꢀ5)2(Hg2+)], exist in equiꢀ
librium in solution (Scheme 5). In the dimeric complex,
there is an additional coordination bond between the metal
cation located in the crown ether cavity of one of the dye
molecules and the sulfonate group of another molecule,
resulting in an increase in stability of the complex (see
Table 4). This additional binding leads to disruption of
mol L–1) in MeCN at 293 K
fl
fl
CPb2+
/mol L–1
λ
max/nm
ϕ
fl
(∆λ /nm)*
2.80•10–6
5.96•10–6
1.19•10–5
2.15•10–5
5.95•10–5
1.88•10–4
0.93•10–3
0.88•10–2
602 (–1)
602 (–1)
597 (4)
596 (5)
596 (5)
598 (3)
598 (3)
593 (8)
0.054
0.036
0.037
0.048
0.057
0.062
0.063
0.071
fl
fl
fl
* ∆λ = (λ max)L – (λ
)
.
max compl

520
Russ.Chem.Bull., Int.Ed., Vol. 56, No. 3, March, 2007
Tulyakova et al.
Scheme 5
the coordination bond between the N atom of the macroꢀ
cycle and the Hg2+ cation. The spectrum of the complex,
in which the involvement of the N atom is insignificant, is
observed at longer wavelengths (λ1 = 470 nm) compared
to the spectrum of the complex, in which the lone elecꢀ
tron pair of the N atom is involved in the coordination
bond with the Hg2+ cation (λ2 = 396 nm). Earlier, we
have found dimeric complexes with Hg2+ cations20 when
studying styryl dyes containing the benzothiacrown group.
The formation of dimeric complexes is confirmed by
electrospray mass spectra. Under the same analysis conꢀ
ditions, we found that an acetonitrile solution of Eꢀ4 in
the presence of Hg2+ contains primarily the [(Eꢀ4)(Hg2+)]
complex, whereas a solution of Eꢀ5 in the presence of
Hg2+ consists of a mixture of the monomeric and dimeric
complexes (Table 6).
All data obtained by analyzing the dimeric complex by
NMR methods suggest the structure of the resulting dimer
(see Scheme 5). For example, the addition of mercury
perchlorate to both dyes Eꢀ4 and Eꢀ5 led to identical
spectral changes, viz., to downfield shifts of the signals of
all protons (Figs 7 and 8). The signals for the protons of
the aliphatic moiety of the molecules are rather difficult
to interpret because of a considerable broadening. The
largest changes in the aromatic region are observed for the
signals of the H(17), H(21) and H(18), H(20) protons
(∆δ 0.74 and 0.28 ppm, respectively) belonging to the
benzene ring in the phenylazadithiacrown group and the
signals for the H(22) and H(23) olefinic protons with the
3
spinꢀspin coupling constant Jtrans = 15.9 Hz (∆δ 0.43
and 0.15 ppm, respectively).
Presumably, the dimeric complex [(Eꢀ5)2(Hg2+)] has
a linear structure (Scheme 6). If the dye molecules are
arranged one above another (dimer stacks), the anisotroꢀ
pic effect is observed, resulting in substantial upfield shifts
1
of the proton signals in the H NMR spectra.20 In the
linear dimer, the effect of the metal cation is analogous
to that observed in the complex of the cationic dye
[(Eꢀ4)(Hg2+)].
The existence of the dimeric complex is additionally
confirmed by the results of an experiment, in which an
excess of Hg2+ cations was added to a solution of this
complex. In this case, a shoulder of the longꢀwavelength
absorption band at 470 nm disappeared. The presence of
excess mercury leads to decomposition of the dimeric
complex to form the [(Eꢀ5)(Hg2+)2] complex, in which
the second Hg atom is coordinated by the sulfonate group
of the Nꢀsulfoalkyl substituent (see Scheme 5).
Fluorescence. The fluorescence quantum yields and
the lifetimes of the excited state of dyes Eꢀ4 and Eꢀ5 and
their complexes in acetonitrile are given in Table 7.
The introduction of the Nꢀsulfonatobutyl group into
the benzothiazolium moiety of the ligand molecule is acꢀ
companied by an increase in the lifetime of the excited
state.
The addition of Hg2+ or Cu2+ to solutions of Eꢀ4 and
Eꢀ5 in MeCN causes shifts of the steadyꢀstate fluoreꢀ
scence spectra of the corresponding ligands to shorter
wavelengths (see Table 7). The hypsochromic shifts in the
absorption spectra of the complexes of Eꢀ4 and Eꢀ5 with
Table 6. ESIꢀMS data for the complexes of dyes Eꢀ4 and Eꢀ5
with mercury perchlorate in acetonitrile
Complex
m/z
Eꢀ4 + Hg2+
Eꢀ5 + Hg2+
407.8 [(4)(Hg2+)]
923.0 [(5)(Hg2+)(ClO4–)],
753.0 [(5)2(Hg2+)(MeCN)(H2O)],
723.0 [(5)2(Hg2+)],
441.9 [(5)(Hg2+)(MeCN)(H2O)],
411.8 [(5)(Hg2+)]

Phenylazathiacrownꢀcontaining styryl dyes
Russ.Chem.Bull., Int.Ed., Vol. 56, No. 3, March, 2007
521
H—C(17)
(H—C(21))
H—C(18)
(H—C(20))
H—C(22)
3Jtrans = 15.2
a
H—C(23)
3Jtrans = 15.2
H—C(29)
H—C(30)
H—C(32)
8.6
8.4
8.2
3Jtrans = 15.9
8.0
7.8
7.6
3Jtrans = 15.9
7.4
7.2
7.2
7.0
7.0
δ
H—C(18)
(H—C(20))
b
c
H—C(23)
H—C(22)
H—C(17)
(H—C(21))
H—C(30)
H—C(31)
H—C(29)
H—C(32)
8.6
8.6
8.4
8.2
8.0
7.8
7.6
H—C(18)
(H—C(20))
7.4
δ
δ
H—C(30)
H—C(22)
3Jcis = 11.6
H—C(17)
(H—C(21))
H—C(29)
H—C(23)
H—C(31)
H—C(32)
3Jcis = 11.6
8.4
8.2
8.0
7.8
7.6
7.4
7.2
7.0
Fig. 7. 1H NMR spectra (the aromatic region) of Eꢀ4 (a), [(Eꢀ4)(Hg2+)] (b), and [(Zꢀ4)(Hg2+)] (c) in CD3CN at 303 K; the spinꢀspin
coupling constants (Hz) are given.
H—C(18)
(H—C(20))
3Jtrans = 15.3
H—C(17)
(H—C(21))
H—C(22)
3Jtrans = 15.3
H—C(30)
H—C(23)
H—C(29)
a
H—C(31)
H—C(32)
8.4
8.2
8.0
7.8
7.6
7.4
7.2
7.0
6.8
6.8
δ
H—C(18)
(H—C(20))
3Jtrans = 15.3
b
H—C(23)
H—C(29)
H—C(22)
H—C(17)
(H—C(21))
H—C(31)
H—C(30)
H—C(32)
8.4
8.2
8.0
7.8
7.6
7.4
7.2
7.2
7.0
δ
H—C(22)
3Jcis = 12.6
H—C(18)
(H—C(20))
c
H—C(29)
H—C(17)
(H—C(21))
H—C(23)
H—C(31) H—C(30)
H—C(32)
3Jcis = 11.6
8.4
8.2
8.0
7.8
7.6
7.4
7.0
6.8
δ
Fig. 8. 1H NMR spectra (the aromatic region) of Eꢀ5 (a), [(Eꢀ5)(Hg2+)] (b), and [(Zꢀ5)(Hg2+)] (c) in CD3CN at 303 K; the spinꢀspin
coupling constants (Hz) are given.
Hg2+ and Cu2+ (see Table 4) were found to be substanꢀ
tially larger than those in the emission spectra. These
phenomena were described in sufficient detail in the litꢀ
erature18,24 and are associated with decoordination of
metal cations from the N atom of the crown fragment in
the excited state. For the [(Eꢀ4)(Cu2+)], [(Eꢀ5)(Cu2+)],
[(Eꢀ4)(Hg2+)], [(Eꢀ5)(Hg2+)], and [(Eꢀ5)2(Hg2+)] comꢀ
plexes, fluorescence quenching relative to the starting
ligand was observed, which may be due to the heavy atom
effect21 in the case of Hg2+ cations.
The fluorescence lifetimes of Eꢀ4 and Eꢀ5 are subꢀ
stantially changed upon complexation. The fluorescence
quenching curves can be described by monoexponential
kinetic equations, except for the complex of Eꢀ5 with
Hg2+ cations. The fluorescence quenching curve for the
latter complex can be described only by a biexponential
kinetic equation with the lifetimes of 94 and 310 ps for the
fast and slow components, respectively. The appearance
of two lifetimes may be associated with the simultaneous
excitation of two different complexes in the ground state.

522
Russ.Chem.Bull., Int.Ed., Vol. 56, No. 3, March, 2007
Tulyakova et al.
Scheme 6
formation of the [(Eꢀ5)2(Hg2+)] complex, and the comꢀ
plexation has no substantial effect on the chromophoric
system.
Table 7. Fluorescence characteristics of dyes Eꢀ4 and Eꢀ5 and
their complexes in MeCN at 295 K
fl
fl
Photochemistry. Earlier,13 we have demonstrated that
irradiation of acetonitrile solutions of styryl dyes causes
the reversible photochemical E—Zꢀisomerization reacꢀ
tion. Upon irradiation of Eꢀ4 and Eꢀ5 with light at λ =
546 nm, the Z isomer was not detected by spectroscopic
methods. This is, apparently, associated with the fact that
relaxation of the excited state of these ligands occurs priꢀ
marily due to rotation about the C—Ph bond accompaꢀ
nied by the transformation into the twisted state, which
can be stabilized in a polar aprotic solvent (MeCN). The
metal cation prevents deactivation of the excited state
of the dye in the [(Eꢀ4)(Hg2+)], [(Eꢀ5)(Hg2+)], and
[(Eꢀ5)2(Hg2+)] complexes through the twisted state, and
the E—Z photoisomerization makes a large contribution to
radiationless deactivation of excitation.18,21 For example,
irradiation of acetonitrile solutions of the [(Eꢀ4)(Hg2+)]
and [(Eꢀ5)(Hg2+)] complexes at λ = 436, 365, and 546 nm
(Figs 9 and 10) causes fast changes in the absorpꢀ
tion spectra due to reversible E—Z photoisomerization
(Scheme 7).
Comꢀ
pound
λ
max/nm
ϕ
Lifetime
(∆λ /nm)a
τ /ps
fl
fl
Eꢀ4
601
0.026
0.013
0.012
0.063
0.057
0.029
0.069
72
96
65
160
220
94
[(Eꢀ4)(Cu2+)]
[(Eꢀ4)(Hg2+)]
Eꢀ5
569 (32)
568 (33)
601
568 (33)
574 (27)b
582 (19)c
[(Eꢀ5)(Cu2+)]
[(Eꢀ5)(Hg2+)]
[(Eꢀ5)2(Hg2+)]
310
a See the note to Table 5.
b
λ
λ
exc = 390 nm.
exc = 470 nm.
c
However, the emission spectrum of the complexes of dye
Eꢀ5 with Hg2+ cations substantially depends on the exciꢀ
tation wavelength. An analysis of the fluorescence quenchꢀ
ing curves for the complexes of Eꢀ5 with Hg2+ cations for
the excitation wavelength changing from 390 to 470 nm
showed that the relative amplitude of the fast component
decreases with changing λ from 390 to 470 nm, whereas
the relative amplitude of the slow component increases.
The appearance of the longꢀlived component may be asꢀ
sociated with the formation of the dimeric complex.
An increase in the lifetime is also typical of the complex
of Eꢀ5 with Cu2+ cations. Earlier, we have noted25 that
dimeric complexes of styryl dye bases with metal cations
have longer lifetimes of the excited state compared to the
monomeric complexes. In addition, the fluorescence
quantum yield changes only slightly upon the formation
of the [(Eꢀ5)2(Hg2+)] complex (unlike the [(Eꢀ4)(Hg2+)]
complex). This can be attributed to the fact that the
N atom of the crown fragment is not involved in the
The absorption spectrum of the Z isomer of the
[(Zꢀ4)(Hg2+)] complex was calculated from the correꢀ
sponding spectra of [(Eꢀ4)(Hg2+)] and the photostationary
states obtained by irradiation with light at wavelengths of
405 and 313 nm (see Fig. 9).26
The possibility of coordination of Hg2+ cations at the
crown and benzothiazolium moieties of the ligand molꢀ
ecule Eꢀ5 leads to the formation of a complex having a
more rigid structure with a smaller number of rotational
degrees of freedom, resulting in an increase of the
nonradiative time for the photostationary state of the
[(Zꢀ5)2(Hg2+)2] complex into the E form by ten times

Phenylazathiacrownꢀcontaining styryl dyes
Russ.Chem.Bull., Int.Ed., Vol. 56, No. 3, March, 2007
523
36 32
28
24
20
ν•103/cm–1
Scheme 7
A
0.8
1
2
3
4
5
6
7
8
0.6
0.4
0.2
300
400
500
600 λ/nm
Fig. 9. Absorption spectra of [(Eꢀ4)(Hg2+)] (C = 2.5•10–5
mol L–1) before (1) and after irradiation with light at λ =
436 (2, 3), 405 (4, 5), 365 (6), and 313 nm (7) for 2 (2, 4, 6, 7),
4 (3), and 10 min (5), and the spectrum of [(Zꢀ4)(Hg2+)] calcuꢀ
lated by Fischer's method (8).
To summarize, we developed a new procedure for the
synthesis of the formyl derivative of phenylazathiacrown
ether. Condensation of the latter with quaternary benzoꢀ
thiazolium salts afforded azathiacrownꢀcontaining styryl
dyes Eꢀ4 and Eꢀ5. The complexation ability of the startꢀ
ing formyl derivative of the phenylazathiacrown comꢀ
36 32
28
24
20
ν•103/cm–1
A
0.8
1
0.6
0.4
0.2
pound toward heavy and transition metal ions (Zn2+
,
Cd2+, Pb2+, Ag+, and Hg2+) was evaluated by the
1H NMR method.
It was found that in acetonitrile, photochromic ligands
Eꢀ4 and Eꢀ5 form complexes with heavy and transition
metal cations, which is accompanied by a hypsochromic
shift of the longꢀwavelength absorption band. In addiꢀ
tion, these ligands exhibit high selectivity and a large
optical response to Hg2+ cations. Due to the involvement
of the sulfonate group of the N substituent (a spacer) in
coordination, ligand Eꢀ5 was demonstrated to be able
to form both monomeric and dimeric complexes with
Hg2+ cations, which differ in the optical characteristics
and stability. The aboveꢀdescribed features can be useful
for the development of new and the improvement of the
already available optical sensors for heavy and transition
metal cations.
5
3
4
2
300
400
500
600
λ/nm
Fig. 10. Absorption spectra of [(Eꢀ5)(Hg2+)] (C = 2.5•10–5
mol L–1) before (1) and after irradiation with light at λ =
436 (2, 3) and 365 nm (4, 5) for 2 (2, 4) and 4 min (3, 5).
compared to the [(Zꢀ4)(Hg2+)] complex. We failed to
calculate the absorption spectrum of the Z isomers of the
[(Zꢀ5)(Hg2+)] and [(Zꢀ5)2(Hg2+)] complexes because
Fischer's method,26 which is used for calculations of abꢀ
sorption spectra of Z isomers, has been developed only for
twoꢀcomponent systems.
Experimental
The light irradiation of solutions of the complexes of
dyes Eꢀ4 and Eꢀ5 with Hg2+ cations causes substantial
changes in the positions of the proton signals in the
1H NMR spectra. The signals for the olefinic protons
H(22) and H(23) at δ 7.10 and 7.79 ([(Zꢀ4)(Hg2+)]) and
at δ 6.74 and 7.47 ([(Zꢀ5)(Hg2+)]) appear as doublets with
the spinꢀspin coupling constants characteristics of Z isoꢀ
mers of olefins (11.6 and 12.6 Hz, respectively; see
Figs 7 and 8).
The TLC monitoring was carried out on DCꢀAlufolien
Kieselgel 60 F254 plates. Column chromatography was performed
on silica gel Kieselgel, 200—600 nm. The melting points (uncorꢀ
rected) were measured on a Melꢀtemp II instrument. The
1H NMR spectra were recorded on Bruker DRXꢀ500
(500.13 MHz) and Bruker DRXꢀ400 (400.13 MHz) spectroꢀ
meters. The chemical shifts and the spinꢀspin coupling conꢀ
stants were measured with an accuracy of 0.01 ppm and 0.1 Hz,
respectively. The mass spectra were obtained on a Varian

524
Russ.Chem.Bull., Int.Ed., Vol. 56, No. 3, March, 2007
Tulyakova et al.
MAT 311A instrument using a direct inlet system; the ionization
energy was 70 eV. The electrospray ionization mass specꢀ
tra (ESIꢀMS, 2 kW) were measured on a JEOL AccuTOF
JMSꢀT100LC mass spectrometer.
N,NꢀBis(2ꢀchloroethyl)aniline (1). NꢀPhenyldiethanolamine
(20 g, 0.11 mol) was added portionwise to phosphorus oxychloꢀ
ride (46 g, 0.3 mol) at 5 °C. The reaction mixture was kept at
100 °C for 1 h, cooled, and poured into benzene (60 mL). The
benzene solution was poured onto ice (100 g). Then the benzene
solution was separated, and the aqueous solution was extracted
with benzene (3×50 mL). The benzene solutions were combined
and dried with sodium sulfate. The solvent was removed on a
rotary evaporator. After recrystallization from hot MeOH, the
yield of compound 1 was 18.6 g (77%), m.p. 44 °C.
The molar concentrations of the solutions of Hg, Pb, Ag,
and Cu perchlorates were determined by direct titration of the
corresponding EDTA solutions in the presence of murexide or
Xylenol orange as the indicator. Acetonitrile of spectral grade
with a water content of <0.005% (Aldrich) was used without
additional purification. Solutions of ligands Eꢀ4 and Eꢀ5 were
prepared and studied under red light. The electronic absorption
spectra were recorded on a VarianꢀCary spectrophotometer and
a Specord Mꢀ40 instrument connected with a computer. The
fluorescence spectra were measured on a FluoroLog (Jobin Yvon)
spectrofluorimeter at 20 1 °C. The fluorescence quantum yields
of the ligands and the complexes were determined for airꢀsatuꢀ
rated acetonitrile solutions at 20 1 °C with the use of 9,10ꢀdiꢀ
4ꢀ[Bis(2ꢀchloroethyl)amino]benzaldehyde (2). A solution of
N,Nꢀbis(2ꢀchloroethyl)aniline (1) (18.6 g, 0.085 mol) in DMF
(65.7 mL) was added to a solution of phosphorus oxychloride
(13.2 g, 0.086 mol) in DMF (65.7 mL) cooled to 0 °C. The
reaction mixture was stored at 15 °C for 15 min, heated at 40 °C
for 2 h, and poured into a mixture of water and ice. Unconsumed
N,Nꢀbis(2ꢀchloroethyl)aniline (1) was rapidly filtered off. The
filtrate was kept at 0 °C for 0.5 h. The precipitate was filtered off
and recrystallized from EtOH. Compound 2 was obtained in a
yield of 14.9 g (71%), m.p. 88 °C (cf. lit. data14: m.p. 85—88 °C).
1H NMR (CDCl3, 30 °C), δ: 3.66 (t, 4 H, H(9), H(14), 3J =
phenylanthracene in cyclohexane as the standard (ϕ = 0.9).
F
The excitation wavelength was 370 nm. The quantum yields
were calculated from the corrected fluorescence spectra. The
complexation of compounds Eꢀ4 and Eꢀ5 with Hg, Cu, Ag,
and Pb perchlorates and perchloric acid was studied by spectroꢀ
photometric titration at 20 1 °C by varying the concentration
of the corresponding perchlorate at a constant concentration of
the ligand. The complexation constants and the absorption specꢀ
tra of the complexes were calculated from the electronic absorpꢀ
tion spectra of solutions using the HYPERQUAD program.19
The timeꢀresolved fluorescence spectra were measured on a sysꢀ
tem consisting of a Chromex 250 spectrograph connected with a
Hamamatsu 5680 streak camera equipped with an M5676 fast
sweep unit (the time resolution was 2 ps). The pulses for fluoresꢀ
cence excitation were generated using a homeꢀmade optical
parametric generator with a further frequency doubling; the
generator was pumped by the second harmonic of a Tiꢀsapphire
femtosecond laser system (Femtopower Compact Pro). All lifeꢀ
times of the excited states were determined using depolarized
excitation light. The maximum energy of the fluorescence exciꢀ
tation pulse was ≤100 nJ, the average power was 0.1 mW, and
the pulse repetition frequency was 1 kHz. The excitation beam
was focussed onto a quartz cell (l = 10 mm) at a spot of a
diameter of 0.1 mm. The convolution of the streak camera slit at
the time scale of 250 ps with a jitter of the electronic startup of
scanning gave a Gaussian (by more than four orders of magniꢀ
tude) apparatus function with a full width at half maximum
(FWHM) of 20 ps. The fluorescence kinetics was analyzed by
fitting the curves with the use of the Levenberg—Marquardt
leastꢀsquares method and the solution of differential equations,
which describe the time behavior of one excited state without
consideration of changes in the occupancy of the ground state
by the equation
3
6.4 Hz); 3.82 (t, 4 H, H(8), H(13), J = 6.4 Hz); 6.73 (d, 2 H,
H(2), H(6), 3J = 8.3 Hz); 7.75 (d, 2 H, H(3), H(5), 3J =
8.3 Hz); 9.76 (s, 1 H, H(11)).
4ꢀ(1,4ꢀDioxaꢀ7,13ꢀdithiaꢀ10ꢀazacyclopentadecꢀ10ꢀyl)benzꢀ
aldehyde (3). Solutions of 1,2ꢀbis(2ꢀmercaptoethoxy)ethane
(1.14 g, 0.006 mol) and 4ꢀ[bis(2ꢀchloroethyl)amino]benzꢀ
aldehyde (1.4 g, 0.006 mol) each in EtOH (75 mL) were simulꢀ
taneously added to a refluxing solution containing cesium carꢀ
bonate (9.3 g, 0.028 mol), EtOH (300 mL), and water (300 mL)
for 1 h. The reaction mixture was stirred at 60 °C for 20 h and
then the solvent was evaporated under vacuum. The residue was
extracted with benzene from water. The extracts were washed
with water and concentrated under vacuum. The residue was
chromatographed on a silica gel column using a 1 : 2 hexꢀ
ane—ethyl acetate mixture as the eluent, m.p. 86 °C. The yield
1
was 1.4 g (65%). H NMR (CDCl3, 30 °C), δ: 2.74 (s, 4 H,
3
H(11), H(15)); 2.88 (t, 4 H, H(2), H(9), J = 7.5 Hz); 3.62 (s,
4 H, H(5), H(6)); 3.70 (t, 4 H, H(3), H(8), 3J = 7.5 Hz); 3.78 (t,
4 H, H(12), H(14), 3J = 4.6 Hz); 6.65 (d, 2 H, H(17), H(21),
3
3J = 8.3 Hz); 7.69 (d, 2 H, H(18), H(20), J = 8.3 Hz); 9.70 (s,
1 H, H(22)). 13C NMR (100 MHz, CDCl3), δ: 29.34 (C(11),
C(15)); 31.43 (C(2), C(9)); 51.96 (C(12), C(14)); 70.67 (C(3),
C(8)); 74.26 (C(5), C(6)); 111.09 (C(17), C(21)); 125.48
(C(16)); 132.18 (C(18), C(20)); 151.69 (C(19)); 189.88 (C(22)).
MS (EI), m/z (Irel (%)): 355 [M+] (100), 282 (9), 269 (4),
220 (8), 204 (24), 192 (22), 160 (32), 147 (34), 134 (23), 118 (12),
104 (8), 87 (12), 74 (13), 60 (11), 45 (11).
2ꢀ{(E)ꢀ2ꢀ[4ꢀ(1,4ꢀDioxaꢀ7,13ꢀdithiaꢀ10ꢀazacyclopentadecꢀ
10ꢀyl)phenyl]vinyl}ꢀ3ꢀethylꢀ1,3ꢀbenzothiazoliumꢀ3 perchlorꢀ
ate (4) and 2ꢀ{(E)ꢀ2ꢀ[4ꢀ(1,4ꢀdioxaꢀ7,13ꢀdithiaꢀ10ꢀazacycloꢀ
pentadecꢀ10ꢀyl)phenyl]vinyl}ꢀ3ꢀ(4ꢀsulfonatobutyl)ꢀ1,3ꢀbenzoꢀ
thiazoliumꢀ3 perchlorate (5). A mixture of 3ꢀethylꢀ2ꢀmethylꢀ
1,3ꢀbenzothiazolium (3ꢀsulfonatobutylꢀ1,3ꢀbenzothiazolium)
perchlorate (0.41 mmol) and compound 3 (0.42 mmol) in pyriꢀ
dine (0.15 mL) and anhydrous EtOH (5 mL) was refluxed on an
oil bath for 30 h. Then the reaction mixture was concentrated.
The residue was washed with hot benzene and MeOH, dried,
and recrystallized from MeOH.
dI(t)/dt = Gauss(t0, ∆t, A) – I(t)/τ,
where I(t) is the fluorescence intensity, τ is the lifetime of the
excited state, Gauss is the Gaussian excitation pulse, t0 is the
time position of the maximum, ∆t is the pulse width, and A is the
pulse amplitude. The initial conditions: I(–∞) = 0. All chosen
2
solutions were characterized by χ larger than 10–4, and the
correlation coefficient R > 0.999. The error of calculations of
the lifetime was ≤0.1 ps. The fluorescence integration time
was ≤90 s.
Compound Eꢀ4. The yield was 0.150 g (58%), m.p.
255—257 °C. Found (%): C, 52.90; H, 5.99; N, 4.41.

Phenylazathiacrownꢀcontaining styryl dyes
Russ.Chem.Bull., Int.Ed., Vol. 56, No. 3, March, 2007
525
C27H35ClN2O6S3. Calculated (%): C, 52.71; H, 5.73; N, 4.55.
1H NMR (CD3CN, 30 °C), δ: 1.63 (t, 3 H, H(34), 3J = 7.3 Hz);
2.81 (t, 4 H, H(11), H(15), 3J = 4.9 Hz); 2.97 (t, 4 H, H(2),
H(9), 3J = 7.9 Hz); 3.65 (s, 4 H, H(5), H(6)); 3.80 (t, 4 H, H(3),
H(8), 3J = 4.9 Hz); 3.84 (t, 4 H, H(12), H(14), 3J = 7.9 Hz);
predominantly of the 1 : 1 composition (ligand : cation) was
obtained. Complex [(Eꢀ5)(Hg2+)]. 1H NMR (CD3CN), δ:
3
1.27 (s); 2.95 (t, 2 H, J = 6.7 Hz); 3.28—3.95 (m, H(2), H(5),
H(6), H(8), H(9), H(11), H(12), H(14), H(15), H(34)); 4.91 (t,
2 H, H(33), 3J = 7.9 Hz); 7.51 (d, 2 H, H(17), H(21), 3J =
3
3
4.72 (q, 2 H, H(33), J = 7.3 Hz); 6.88 (d, 2 H, H(17), H(21),
7.3 Hz); 7.70 (t, 1 H, H(29), J = 7.9 Hz); 7.88 (t, 1 H, H(30),
3J = 9.2 Hz); 7.32 (d, 1 H, H(22), 3Jtrans = 15.2 Hz); 7.71 (t, 1 H,
H(31), 3J = 7.9 Hz); 7.82 (t, 1 H, H(2), H(31), 3J = 8.5 Hz);
3J = 7.9 Hz); 7.97 (d, 1 H, H(22), Jtrans = 15.2 Hz); 8.01 (d,
3
1 H, H(28), 3J = 9.7 Hz); 8.08 (d, 1 H, H(23), 3Jtrans = 15.2 Hz);
3
3
7.83 (d, 2 H, H(18), H(20), J = 9.2 Hz); 7.97 (d, 1 H, H(29),
8.15 (d, 2 H, H(18), H(20), J = 7.3 Hz); 8.22 (d, 1 H, H(31),
3
1
3J = 8.5 Hz); 8.03 (d, 1 H, H(23), Jtrans = 15.2 Hz); 8.15 (d,
3J = 7.9 Hz). Complex [(Zꢀ5)(Hg2+)]. H NMR (CD3CN), δ:
1 H, H(32), 3J = 7.9 Hz). 13C NMR (100 MHz, DMSOꢀd6), δ:
13.47 (C(34)); 28.85 (C(2), C(9)); 30.63 (C(11), C(15)); 43.2
(C(33)); 51.10 (C(12), C(14)); 69.67 (C(3), C(4)); 72.50 (C(5),
C(6)); 105.58 (C(22)); 111.6 (C(17), C(19)); 115.34 (C(29));
123.59 (C(23)); 127.16 (C(30)); 128.68 (C(31)); 132.76 (C(18),
C(20)); 149.96 (C(32)). ESIꢀMS of ligand Eꢀ4 in MeCN, m/z:
515.0 [Eꢀ4]+.
1.27 (s); 3.39—3.94 (m, H(2), H(5), H(6), H(8), H(9), H(11),
3
H(12), H(14), H(15), H(34)); 6.74 (d, 1 H, H(22), Jcis
=
12.6 Hz); 7.06 (d, 2 H, H(17), H(21), 3J = 6.1 Hz); 7.23 (d, 2 H,
H(18), H(20), 3J = 6.1 Hz); 7.47 (d, 1 H, H(23), 3Jcis = 11.6 Hz);
7.81 (t, 1 H, H(29), 3J = 6.8 Hz); 7.97 (t, 1 H, H(30), 3J =
6.8 Hz); 8.15 (d, 1 H, H(28), 3J = 7.9 Hz); 8.23 (d, 1 H, H(31),
3J = 7.9 Hz). ESIꢀMS of a solution of ligand Eꢀ5 in MeCN in
the presence of Hg2+ cations, m/z: 923.0 [(Eꢀ5)(Hg2+)(ClO4–)],
753.0 [(Eꢀ5)2(Hg2+)(MeCN)(H2O)], 723.0 [(Eꢀ5)2(Hg2+)],
Compound Eꢀ5. The yield was 0.165 g (63%), m.p.
234—236 °C. Found (%): C, 55.74; H, 6.45; N, 4.48.
C29H38N2O5S4. Calculated (%): C, 55.92; H, 6.15; N, 4.50.
1H NMR (CD3CN), δ: 1.25 (t, 2 H, H(35), 3J = 7.3 Hz); 2.76 (t,
4 H, H(11), H(15), 3J = 4.9 Hz); 2.80 (t, 2 H, H(34), 3J =
661.0
[(Eꢀ5)(K+)],
645.0
[(Eꢀ5)(Na+)],
441.9
[(Eꢀ5)(Hg2+)(MeCN)(H2O)], 411.8 [(Eꢀ5)(Hg2+)].
Photochemical transformations were performed by irradiatꢀ
ing acetonitrile solutions of Eꢀ4, Eꢀ5, [(Eꢀ4)(Hg2+)], and
[(Eꢀ5)(Hg2+)] with a light of a mercury lamp (DRKꢀ120, 120 W).
The lines of the mercury lamp spectrum were separated with the
use of glass light filters from a standard kit of colored glass light
filters (UFSꢀ2 + ZhSꢀ3, UFSꢀ6 + BSꢀ7, PSꢀ13 + ZhSꢀ10, and
PSꢀ7 + SZSꢀ21 + ZhSꢀ18 for separation of lines at λ = 313, 365,
405, and 546 nm, respectively). The photoprocesses were studꢀ
ied with stirring in a 1ꢀcm quartz cell equipped with a fluoroplast
3
6.7 Hz); 2.91 (t, 4 H, H(2), H(9), J = 7.3 Hz); 3.12 (m, 2 H,
H(36)); 3.66 (s, 4 H, H(5), H(6)); 3.77 (t, 4 H, H(12), H(14),
J = 4.9 Hz); 4.74 (t, 2 H, H(33), 3J = 7.9 Hz); 6.77 (d, 2 H,
3
3
H(17), H(21), J = 8.5 Hz); 7.64 (t, 1 H, H(29), J = 7.3 Hz);
7.66 (d, 1 H, H(22), 3Jtrans = 15.2 Hz); 7.74 (t, 1 H, H(30), 3J =
7.9 Hz); 7.87 (d, 2 H, H(18), H(20), 3J = 8.5 Hz); 7.94 (d, 1 H,
H(23), 3Jtrans = 15.2 Hz); 8.00 (d, 1 H, H(28), 3J = 7.9 Hz); 8.05
(d, 1 H, H(31), J = 7.9 Hz). ESIꢀMS of ligand Eꢀ5 in MeCN,
m/z: 661.0 [(Eꢀ5)(K+)], 645.0 [(Eꢀ5)(Na+)], 623.1 [(Eꢀ5)(Na+)].
Synthesis and analysis of complexes of ligand Eꢀ4 with Hg2+
perchlorate in MeCN. A solution of Hg(ClO4)2 (1.25•10–3
mol L–1) in MeCN (66 µL) was added to a solution of Eꢀ4
(2.5•10–5 mol L–1) in MeCN (2.934 mL) prepared by dilution
of the stock solution (1.99•10–3 mol L–1). A complex predomiꢀ
nantly of the 1 : 1 composition (ligand : cation) was obtained.
stopper; the radiation intensity was 5.233•10–6 Einstein s–1 L–1
.
To calculate the spectrum of Zꢀ4 by Fischer's method, a soluꢀ
tion of Eꢀ4 was irradiated with light at λ = 365 and 436 nm
until the corresponding photostationary states were established;
to calculate the spectrum of Zꢀ5, at λ = 313, 365, 405, and
436 nm.
Xꢀray diffraction study. Single crystals of 3 suitable for Xꢀray
diffraction study were grown by crystallization from a hexane
solution. A single crystal coated with perfluorinated oil was
mounted on a Bruker SMART CCD diffractometer. The experiꢀ
mental Xꢀray data were collected at low temperature. The crysꢀ
tal parameters and the Xꢀray diffraction data collection and
refinement statistics for compound 3 are given in Table 8. The
structure was solved by direct methods and refined by the fullꢀ
matrix leastꢀsquares method against F 2 with anisotropic disꢀ
placement parameters for all nonhydrogen atoms. The H atoms
were located in difference Fourier maps and refined isotropically.
The unusually high residual electron density maxima are, apꢀ
parently, attributed to an additional disorder of the macrocycles
over a number of closely spaced positions of the S atoms. All
highest electron density peaks are located near these atoms. This
conclusion is consistent with high flexibility of the macrocycle.
All calculations were carried out using the SHELXTLꢀPlus proꢀ
gram package.27 The results were deposited with the Cambridge
Structural Database (CSDꢀ632898).*
1
Complex [(Eꢀ4)(Hg2+)]. H NMR (CD3CN), δ: 1.59 (t, 3 H,
H(34), 3J = 7.3 Hz); 3.41—3.51 (m, 8 H, H(2), H(9), H(11),
H(15)); 3.73 (br.s, 6 H, H(5), H(6), H(8)); 3.99 (s, 4 H, H(12),
3
H(14)); 4.90 (q, 2 H, H(33), J = 7.3 Hz); 7.62 (d, 2 H, H(17),
H(21), 3J = 8.5 Hz); 7.73 (d, 1 H, H(22), 3Jtrans = 15.9 Hz); 7.86
(t, 1 H, H(31), 3J = 7.9 Hz); 7.95 (t, 1 H, H(2), H(31), 3J =
7.9 Hz); 8.11 (d, 2 H, H(18), H(20), 3J = 8.5 Hz); 8.16 (d, 1 H,
H(29), 3J = 8.5 Hz); 8.18 (d, 1 H, H(23), 3Jtrans = 15.9 Hz); 8.30
(d, 1 H, H(32), 3J = 7.9 Hz). ESIꢀMS of ligand Eꢀ4 in MeCN in
the presence of Hg2+ cations, m/z: 407.8 [(Eꢀ4)(Hg2+)], 339.7
[(Hg2+)2(ClO4–)2(MeCN)2]. Complex [(Zꢀ4)(Hg2+)]. 1H NMR
3
(CD3CN), δ: 1.59 (t, 3 H, H(34), J = 7.3 Hz); 3.23—3.67 (m,
8 H, H(2), H(9), H(11), H(15)); 4.81 (q, 2 H, H(33), 3J =
7.3 Hz); 5.55—6.13 (m, 12 H, H(5), H(6), H(8), H(12), H(14),
3
H(15)); 7.10 (d, 1 H, H(22), Jcis = 11.6 Hz); 7.47 (d, 2 H,
H(17), H(21), 3J = 8.1 Hz); 7.56 (d, 2 H, H(18), H(20), 3J =
3
8.1 Hz); 7.79 (d, 1 H, H(23), Jcis = 11.6 Hz); 7.80 (t, 1 H,
3
H(31), 3J = 7.8 Hz); 7.91 (t, 1 H, H(30), J = 7.8 Hz); 8.11 (d,
3
1 H, H(29), J = 8.3 Hz); 8.17 (d, 1 H, H(32), 3J = 8.3 Hz).
Synthesis and analysis of complexes of ligand Eꢀ5 with Hg2+
perchlorate in MeCN. A solution of Hg(ClO4)2 (1.25•10–3
mol L–1) in MeCN (66 µL) was added to a solution of Eꢀ5
(2.5•10–5 mol L–1) in MeCN (2.934 mL) prepared by dilution
of the concentrated solution (3.21•10–4 mol L–1). A complex
* These data can be obtained, free of charge, on application to
the Cambridge Crystallographic Data Centre: CCDC, 12 Union
Road, Cambridge CB21EZ, UK (fax: (+44) 12 2333 6033;
eꢀmail: deposit@ccdc.cam.ac.uk).

526
Russ.Chem.Bull., Int.Ed., Vol. 56, No. 3, March, 2007
Tulyakova et al.
Table 8. Crystal parameters and the Xꢀray diffraction data colꢀ
lection and refinement statistics for compound 3
5. G. W. Gokel, W. Matthew Leevy, and M. E. Weber, Chem.
Rev., 2004, 104, 2723.
6. M. G. Voronkov and V. I. Knutov, Sulfur Rep., 1986, 6,
No. 3, 137.
7. R. M. Izatt, K. Pawlak, J. S. Bradshaw, and R. L. Bruening,
Chem. Rev., 1991, 91, 1721.
8. V. V. Litvinova and A. V. Anisimov, Chem. Heterocycl. Comp.,
1999, 12, 1587.
9. A. P. De Silva, H. Q. N. Gunaratne, T. Gunnlaugsson, A. J.
M. Huxley, C. P. McCoy, J. T. Rademacher, and T. E.
Rice, Chem. Rev., 1997, 97, 1515.
10. D. Jimenez, R. MartinezꢀManez, F. Sancenon, J. V. RosꢀLis,
J. Soto, Á. Benito, and E. GarciaꢀBreijo, Eur. J. Inorg. Chem.,
2005, 2393.
11. T. F. Baumann, J. G. Reynolds, and G. A. Fox, React.
Funct. Polym., 2000, 44, 111.
Parameter
Characteristic
Molecular formula
Molecular weight (kg kmol–1
Crystal system
Space group
a/Å
b/Å
α/deg
C17H25NO3S2
355.50
)
Triclinic
P–1
8.248(5)
14.618(8)
102.024(3)
104.931(2)
1799.2(2)
4
γ/deg
V/Å3
Z
ρ
calc/g cm–3
1.312
F(000)
760
0.310
0.42×0.38×0.32
123.0(2)
MoꢀKα (0.71073)
ω
12. E. N. Ushakov, S. P. Gromov, O. A. Fedorova, and M. V.
Alfimov, Izv. Akad. Nauk, Ser. Khim., 1997, 484 [Russ. Chem.
Bull., 1997, 46, 463 (Engl. Transl.)].
13. S. P. Gromov, E. N. Ushakov, O. A. Fedorova, V. A.
Soldatenkova, and M. V. Alfimov, Izv. Akad. Nauk, Ser.
Khim., 1997, 1192 [Russ. Chem. Bull., 1997, 46, 1143 (Engl.
Transl.)].
14. M. V. Rubtsov and A. G. Baichikov, Sinteticheskie khimikoꢀ
farmatsevticheskie preparaty [Synthetic Chemical Pharmaceuꢀ
ticals], Ed. A. G. Natradze, Meditsina, Moscow, 1971, 67
(in Russian).
µ(MoꢀKα)/mm–1
Crystal dimensions/mm
T/K
Radiation (λ/Å)
Scan mode
θꢀScanning range/deg
Ranges of reflection
indices
1.32—27.00
–9 ≤ h ≤ 10, –18 ≤ k ≤ 18,
–21 ≤ l ≤ 20
8979
Number of measured
reflections
Number of independent
reflections
Number of reflections
7020
(Rint = 0.0247)
5358
15. O. A. Fedorova, A. I. Vedernikov, O. V. Eshcheulova, P. V.
Tsapenko, Yu. V. Pershina, and S. P. Gromov, Izv. Akad.
Nauk, Ser. Khim., 2000, 1881 [Russ. Chem. Bull., Int. Ed.,
2000, 49, 1853].
with I > 2σ(I )
Number of refinement
variables
R Factors based on
reflections with I > 2σ(I )
R Factors based on
all reflections
Goodnessꢀofꢀfit on F 2
Residual electron
density/e Å–3 (min/max)
607
16. S. P. Gromov, O. A. Fedorova, E. N. Ushakov, O. B.
Stanislavskii, I. K. Lednev, and M. V. Alfimov, Dokl. Akad.
Nauk SSSR, 1991, 317, 1134 [Dokl. Chem., 1991 (Engl.
Transl.)].
R1 = 0.0895,
wR2 = 0.233
R1 = 0.112,
wR2 = 0.249
1.073
17. R. D. Shannon, Acta Crystallogr., 1976, 32A, 751.
18. M. B. Valeur, Molecular Fluorescence: Principles and Appliꢀ
cation, WileyꢀIntersci. Publ., New York, 2001, Ch. 10, 299.
19. P. Gans, A. Sabatini, and A. Vacca, Talanta, 1996, 43, 1739.
20. M. V. Alfimov, S. P. Gromov, Y. V. Fedorov, O. A. Fedorova,
A. I. Vedernikov, A. V. Churakov, L. G. Kuz´mina, J. A.
Howard, S. Bossmann, A. Braun, M. Woerner, D. F. Sears,
and J. Saltiel, J. Am. Chem. Soc., 1999, 121, 4992.
21. K. Rurack, J. L. Bricks, G. Reck, R. Radeglia, and
U. ReschꢀGenger, J. Phys. Chem. A, 2000, 104, 3087.
22. T. E. Jones, D. B. Rorabacher, and L. A. Ochrymowycz,
J. Am. Chem. Soc., 1975, 97, 7485.
–0.912/2.903
This study was financially supported by the Russian
Foundation for Basic Research (Project No. 05ꢀ03ꢀ
33201), the INTAS (Grant 03ꢀ51ꢀ4696), and the US Ciꢀ
vilian Research and Development Foundation (CRDF,
Grant RUC2ꢀ2656ꢀMOꢀ05).
23. A. R. Amundsen, J. Whelan, and B. Bosnich, J. Am. Chem.
Soc., 1977, 99, 6730.
24. R. Mathevet, G. Jonusauskas, and C. Rulliere, J. Phys.
Chem., 1995, 99, 15709.
References
25. Y. V. Fedorov, O. A. Fedorova, E. N. Andryukhina, N. E.
Shepel, M. M. Mashura, S. P. Gromov, L. G. Kuzmina,
A. V. Churakov, J. A. K. Howard, E. Marmois, J. Oberlé,
G. Jonusauskas, and M. V. Alfimov, J. Phys. Org. Chem.,
2005, 18, 1032.
26. E. Fischer, J. Phys. Chem., 1967, 71, 3704.
27. SHELXTLꢀPlus. Release 6.10, Bruker AXS Inc., Madison,
Wisconsin, USA, 2000.
1. G. R. Newkome, C. N. Moorefield, and F. Vogtle, Dendritic
Macromolecules: Concepts, Syntheses, Perspectives, Wileyꢀ
VCH, New York, 1997.
2. J. Leonard, B. Lygo, and G. Procter, Advanced Practical
Organic Chemistry, 2nd ed., Stanley Thornes, England, 1998.
3. B. Sakmann and E. Neher, SingleꢀChannel Recording,
Plenum, New York, 1995.
4. B. Hille, Ionic Channels of Excitable Membranes 3/e, 3rd ed.,
Sinauer Associates, Sunderland, MA, 2001.
Received September 19, 2006;
in revised form January 26, 2007