The Interconnection of Two Positive Charges by Conjugation and Cross-Conjugation in Bis-Quinolinium Ethynyls

Article abstract of DOI:10.1002/ejoc.201900816

1,4-Diethynylbenzene was used as conjugated all-carbon and rigid spacer between the 2-, 3- and 4-positions of two 1-methylquinolinium rings. Thus, for a systematic study, a series of dicationic salts with 2,2-, 3,3-, 4,4-, 3,2-, and 3,4-interconnections of the two positive charges was prepared, in which all even-numbered substitution patterns are conjugated, and all odd-numbered substitution patterns are cross-conjugated. As a consequence, conjugated/conjugated, cross-conjugated/cross-conjugated, and conjugated/cross-conjugated dications have been prepared. The different combinations result in considerably different charge distributions of the positive charges within the π-electron systems according to the rules of resonance which translate into different DFT-calculated frontier orbital profiles and spectroscopic properties such as ¹³C NMR chemical shifts, IR and Raman absorptions, and the measured as well as calculated UV/Vis spectra.

Full text of DOI:10.1002/ejoc.201900816

A Journal of
Accepted Article
Title: The interconnection of two positive charges by conjugation and
cross-conjugation in bis-quinolinium ethynyls.
Authors: Sviatoslav Batsyts, Eike Hübner, Jan C Namyslo, and
Andreas Schmidt
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To be cited as: Eur. J. Org. Chem. 10.1002/ejoc.201900816
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European Journal of Organic Chemistry
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The interconnection of two positive charges by conjugation and
cross-conjugation in bis-quinolinium ethynyls.
Sviatoslav Batsyts, Eike G. Hübner, Jan C. Namyslo, and Andreas Schmidt*
Abstract: 1,4-Diethynylbenzene was used as conjugated all-carbon
and rigid spacer between the 2-, 3- and 4-positions of two 1-
methylquinolinium rings. Thus, for a systematic study a series of
dicationic salts with 2,2-, 3,3-, 4,4-, 3,2-, and 3,4-interconnections of
the two positive charges was prepared, in which all even-numbered
substitution patterns are conjugated, and all odd-numbered
substitution patterns are cross-conjugated. As a consequence,
conjugated/conjugated, cross-conjugated/cross-conjugated, and
conjugated/cross-conjugated dications have been prepared. The
different combinations result in considerably different charge
distributions of the positive charges within the -electron systems
according to the rules of resonance which translate into different DFT-
calculated frontier orbital profiles and spectroscopic properties such
(o) atoms. Heterocyclic molecules which contain classical Kekulé
fragments in addition to one or more 2 heteroatoms such as
nitrogen, for which pyridone 3 is an example, can be represented
by fully covalent neutral structures with alternating double bonds
and pairs of electrons located on each heteroatom, although
zwitterionic resonance forms can be drawn. The oxygen of
pyridone 3 is attached to a starred position of the pyridine ring (3-
I).
13
as C NMR chemical shifts, IR and Raman absorptions, and the
measured as well as calculated UV-Vis spectra.
Introduction
The type of conjugation of -electronic systems greatly governs
their chemical and physical characteristics. In hydrocarbon
chemistry, the term “cross-conjugation”[1] has been used to
characterize any compound possessing branched conjugated
systems[2],[3] with a more disjointed electronic communication in
comparison to linear conjugated systems in which the
[
4]
delocalization is thought to be more significant. In the case of
polyenes and related hydrocarbons, for example, cross-
conjugated dendralenes display remarkable inhibitions of the
delocalization compared to linear polyenes so that they can be
considered as sets of isolated butadiene units.[2] Considerable
effort is currently being directed toward studying the differences
of linear conjugation in comparison to cross-conjugation of
organic molecules from the perspective of computational
Scheme 1. Some characteristics of conjugation and cross-conjugation.
chemistry,[ materials chemistry of electrochromic molecules,
5]
[6]
heteroelement chemistry for which phenylene-bridged 1,2,3-
[
7]
trisilacyclopentadienes can be given as an example here,
The distinction between different types of conjugation has gained
great importance for the classification and deeper understanding
of the chemical and physical properties of heterocyclic mesomeric
betaines. For example, installing the oxygen to the 3-position of a
pyridinium ring results in the construction of a conjugated
heterocyclic mesomeric betaine (CMB).[11,12] These can
polymer chemistry,[8] and even mathematics. Scheme 1 shows
,3,5-hexatriene 1 as an example of a Kekulé even alternant
[9]
1
hydrocarbon which generally have classical polyene structures,[
as well as its cross-conjugated isomer 3-methylenepenta-1,4-
diene 2. In alternant hydrocarbons atoms of like parity are not
directly bonded, i.e. all bonds are those of starred (*) to unstarred
10]
exclusively be represented by dipolar canonical forms in which
the positive and the negative charges are delocalized within the
common -electron system. Betaine 3 is isoconjugated with an
Dr. S. Batsyts, Prof. Dr. Eike G. Hübner, Dr. J. C. Namyslo,
Prof. Dr. A. Schmidt
Clausthal University of Technology, Institute of Organic Chemistry,
Leibnizstrasse 6, D-38678 Clausthal-Zellerfeld (Germany)
E-mail: schmidt@ioc.tu-clausthal.de
[11]
odd alternant hydrocarbon in which the substitutent at C3 is a
starred position (4-I). Common sites for positive and negative
charges exist in the resonance forms as shown by 4-II. By
contrast, in cross-conjugated heterocyclic mesomeric betaines
such as 5, the charges are exclusively delocalized in separated
parts of the -electron system. The anionic partial structure – the
carboxylate – is joined to the cationic partial structure through its
unstarred position (5-I). No common sites for positive and
http://www.ioc.tu-clausthal.de
Supporting information for this article is given via a link at the end of the
document.
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European Journal of Organic Chemistry
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negative charges exist in the resonance forms (5-II). The physical
and chemical consequences are significant.[11,12] Thus, the
permanent dipole moments differ considerably.[13] Conjugated
mesomeric betaines mainly undergo 1,3-dipolar cycloadditions,
whereas the cross-conjugated mesomeric betaines react
We chose the quinolinium cation as model compound to take
advantage of the additional stabilization by the benzo annelation,
and 1,4-diethynylbenzene as all-carbon linker molecules to
exclude the influence of configuration.
[
11]
predominantly as 1,4-dipoles. The differences are also well
reflected in the frontier orbital profiles. The highest occupied Results and Discussion
HOMO) and lowest unoccupied (LUMO) molecular orbitals of the
(
conjugated systems 3 and 4 are very similar. By contrast, the
HOMO of the cross-conjugated mesomeric betaine 5 is almost
exclusively located in the carboxylate fragment, whereas the
LUMO is essentially located in the pyridinium ring. Recently, five
distinct types of conjugation have been identified in heterocyclic
mesomeric betaines by a matrix-connectivity analysis,[14] so that
research in the field of conjugation gets an additional impetus.
First, 1,4-diethynylbenzene 8 was synthesized in two steps from
1,4-dibromobenzene 6 and 2-methyl-butyn-2-ol (MEBYNOL) via
7 according to modified literature-known procedures[18] (Scheme
3). The non-symmetric ethynyl quinolines 10a,b were finally
prepared in two consecutive Sonogashira reactions.[19]
In continuation of our projects dealing with oligocationic
heteroaromatics[15] as well as mesomeric betaines[16] and the
translation of their distinct types of conjugation into chemistry
such as N-heterocyclic carbene formations,[17] we became
interested in interconnecting two positive charges by conjugation
and cross-conjugation and to compare the properties of the
resulting systems. Series of combinations are possible by joining
unsaturated spacers between the 2-, 3-, or 4-positions of two
pyridinium rings, respectively (Scheme 2). A 2-yl and 4-yl-
substitution results in a starred position at the terminal acetylene
position of the building block C*, which can itself be joined to a
starred (C2, C4) or to an unstarred position (C3) of the second
o
pyridinium. Vice versa, the unstarred terminal acetylene C ,
resulting from a substitution at C3 of the pyridinium, can be joined
to the 2-, 3-, and 4-positions of the second pyridinium ring. This
results in all possible -electronic communications by
conjugation/cross-conjugation combinations between two
cationic substituents and enables the study of spectroscopic
consequences.
Scheme 3. Synthesis of non-symmetric diquinoline compounds connected via
1,4-di(ethynyl)benzene spacers.
Subsequently, 1,4-diethynylbenzene 8 was reacted with an
excess of halogenated quinolines under Sonogashira conditions
to give the symmetric ethynyl quinolines 10c-e[
18,19]
(Scheme 4).
Scheme 4. Synthesis of symmetric diquinoline compounds connected via 1,4-
di(ethynyl)benzene spacers.
For the preparation of dicationic species, an excess (2.5 equiv) of
dimethyl sulfate was used (Scheme 5). The salts 11a-e were
formed in almost quantitative yields. Changing the counterions to
Scheme 2. Systematic design of model compounds for this study. Some
examples.
dihexafluorophosphates then gave the salts 11с-e2PF
6
the
spectroscopic properties of which do not differ considerably from
those of 11c-e.
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European Journal of Organic Chemistry
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affected than quinolinium-C≡C-C
6
4
H - carbon atom. The 3,2-
interconnection of 11a (cross-conjugation/conjugation) shows the
chemical shifts of both types of conjugation at 86.8/93.6 ppm and
6 4
84.6/107.1 ppm. The quinolinium-3-yl-C≡C-C H - signal is shifted
more downfield in agreement with its characterization as possible
site for the positive charge in the resonance forms. The selected
values which are assigned to the structures in Scheme 6 show
that the 13C NMR signals of some positions are not influenced
significantly. Very similar effects can be observed for the 3,4- and
4,4-interconnections (c.f. Supporting Information).
-
-,
4 6
Scheme 5. Synthesis of diquinolinium salts. The anions (2 MeSO or 2 PF
respectively) were omitted for the sake of clarity
The different interconnections translate into different charge
distributions according to the rules of resonance and cause
characteristic spectroscopic properties. Thus, the 3,2-
interconnection of dication 11a allows for the formulation of the
positive charge of the conjugated quinolinium-2-yl substituent on
the nitrogen atom as well as on every second atom of the entire
-conjugated system. Bearing in mind that not all canonical forms
contribute equally to the true molecule according to the rules of
resonance,[ this formal distribution includes, however, the
quinolinium-3-yl-substituent, which is by itself in cross-
conjugation to the ethynyl linker. Therefore the positive charge of
the quinolinium-3-yl substituent of 11a can exclusively be
formulated within the heteroaromatic. Its cross-conjugation
prevents the delocalization of the positive charge into the spacer.
As a consequence, five atoms can be identified as possible
independent sites of either positive charge. The 2,2-
interconnection of the two positive charges of 11c, however,
allows for the formulation of the charges on every atom of the -
electron system, and the nitrogen atoms are formal sites for both
of them. This mesomeric structure undoubtedly is highly
unfavorable, although it is allowed according to the rules of
resonance. By contrast, the 3,3-interconnection of 11d with two
quinolinium rings in cross-conjugation with respect to the spacer
causes a separation of the positive charges of the quinolinium
rings, respectively, according to the rules of resonance. Marked
differences can be seen in the 13C NMR spectra of 11a,c,d.
Obviously, triple bonds in conjugation (2-yl or 4-yl) are much more
polarized than those in cross-conjugation (3-yl). As example, the
C≡C resonance frequencies of 11c appear at 85.1 ppm / 106.6
ppm (conjugation/conjugation) and at 85.8 ppm / 93.9 ppm in 11d
20]
Scheme 6. Selected mesomeric forms of 11a (above), 11c (middle), and 11d
below), and charge distribution according to the rules of resonance. Selected
C NMR signals.
(
1
3
DFT calculations (6-31G* / PBE0) of the salts 11a,c,d show that
all three isomers are planar. The methyl groups adopt a trans
configuration as shown. Some values of calculated bond lengths
are presented in Scheme 7. All triple bonds are slightly longer
than in the C≡C triple bond of acetylene (118 pm) according to
the calculation, and the adjacent single bonds are shorter than
literature values of Csp2-Csp bonds (e.g. 143 pm in vinylacetylene).
(
cross-conjugation/cross-conjugation). As expected from the
resonance forms, the quinolinium-C≡C-C - atom is more
6
H
4
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European Journal of Organic Chemistry
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These can be seen as small contributions of cumulene type
resonance structures especially in 11a and 11c. The calculated
HOMO/LUMO profiles of the isomers also differ characteristically.
The LUMO profiles of 11a,c,d clearly reflect the delocalization of
two positive charges in conjugated systems obtained from their
mesomeric structures. In all three cases, the LUMO atomic orbital
coefficients of fused phenyl rings are smaller than the analogous
coefficients in the pyridine ring. The HOMO profiles in all three
cases are comparable and carry the highest atomic orbital
coefficients on the C≡C triple bonds and on the central phenyl ring
0
0
0
,7
,6
,5
3,2-interconnection
2,2-interconnection
3,3-interconnection
0,4
0,3
0,2
0,1
0,0
(
c.f. Supporting Information).
2100
2150
2200
2250
2300
wavenumber, cm-1
Figure 1. Raman spectra of 11a,c,d.
1
0
0
0
0
0
0
0
0
0
0
,0
,9
,8
,7
,6
,5
,4
,3
,2
,1
,0
Scheme 7. Selected bond lengths in pm (above) and lowest unoccupied
molecular orbitals (below).
3
75
400
425
450
475
500
525
550
The IR absorption spectra also reflect the differences between
conjugation and cross-conjugation (Figure 1). Thus, the CC triple
bond absorption values in the corresponding IR spectra of 11d
Wavelength, nm
are 2219 cm , but 2203 cm of 11a and 2200 cm-1 of 11c. The
-
1
-1
Figure 2. UV-Vis spectra of 11a-e in acetonitrile, respectively.
Raman spectra showed similar absorption values of the triple
-
1
-1
bonds at 2219 cm (11d) and 2206 cm (11c). Consequently, 11a
displays two absorption values at 2204 cm-1 and 2219 cm-1
Calculations of the UV/Vis spectra for the three dicationic salts
1a,c,d as model compounds were performed with the 6-31G*
(
shoulder).
1
basis set and PBE0 density functional. Calculations did not
include the influence of solvents, from which an impact can be
The distinct types of conjugation of the -extended dicationic salts
1a-e are also well expressed by their UV-Vis spectra (Figure 2).
expected with increasing polarity; however, changing the solvent
1
N
from acetonitrile (E
5.4; E N
T
(30) 45.6; E
T
T
0.460) to methanol (E (30)
Thus, the salts 11c,e possessing conjugated 2,2-/4,4-
interconnections display absorption maxima at approximately 408
nm, whereas the salt 11d with cross-conjugated 3,3-
interconnections shows a maximum at 369 nm. The salts 11a,b
possessing either type of conjugation (2,3- and 4,3-
interconnections) show peaks at 394 nm in acetonitrile,
respectively.
5
T
0.762) causes essentially no solvatochromism as can
be seen from all experimental UV-Vis spectra shown in the
Supporting Information. The calculated UV transitions
(
wavelength, nm) and the intensities (oscillator strength) are also
given in the Supporting Information. The first twelve transitions for
the three compounds have been calculated. In case of salt 11c
only the first transition at 410 nm is intense, whereas the other
transitions are smaller. The first transition at 410 nm is caused by
an allowed excitation from the HOMO to the LUMO. Its value is
close to the measured spectra in acetonitrile (408 nm).
Calculations of the salt 11d give two transitions at 446 and 351
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European Journal of Organic Chemistry
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nm. The first mentioned transition corresponds to the HOMO-
LUMO excitation, and the second, which is more intense, is the
HOMO-LUMO+2 excitation. All frontier orbitals are given in
Supporting Information. The measured UV/Vis spectra of 11d
display absorptions in the range from 367 to 371 nm which likely
correspond to the HOMO-LUMO+2 excitation. In the case of the
salt 11a, calculations do not show only one, but several allowed
transitions. The first one at 420 nm corresponds to the HOMO-
LUMO excitation, whereas the second one at 392 nm is the
HOMO-LUMO+1 transition. In addition, some weaker absorptions
have been calculated at 322, 315, and 292 nm, respectively.
Considering that the calculated UV spectra were performed in
vacuo the spectra show the correct tendency with the
experimental data.
DFT calculations on the same level of theory. Orbital plots were obtained
using Jmol 14.27.2. Partial charges were obtained with NBO 5.9 [23] from
the results of the DFT calculations.
General procedure of the Sonogashira-Hagihara coupling (Procedure
1
): The reactions were carried out under a nitrogen atmosphere. A mixture
of 5 mmol of the aryl halides, 1 mol % of Pd(PPh Cl , and 2 mol % of CuI
was suspended in 7 mL of anhydrous NEt with stirring. A sample of the
corresponding ethyne (1.05 equiv) in dry NEt was added dropwise at
3
)
2
2
3
3
ambient temperature. The resulting solutions were then stirred at reflux
temperature until complete conversion was monitored by TLC. The
mixtures were then allowed to cool to rt. The solvents were removed in
vacuo. The resulting residues were finally purified by column
chromatography (petroleum ether: ethyl acetate) to afford the products.
4
,4'-Benzene-1,4-diylbis(2-methylbut-3-yn-2-ol) (7):
Procedure 1, a solution of 4.720 g (20.00 mmol) of 1,4-dibromobenzene 6,
.140 g (0.2 mmol) of Pd(PPh Cl , 0.076 g (0.4 mmol) of CuI, and 5.040
g (60.00 mmol) of MEBYNOL in 50 mL of anhydrous NEt were reacted.
Yield 4.792 g, 99%, a white solid, m.p. 159-160 °C. 1H NMR (400 MHz,
CDCl ): δ = 7.35 (m, 4H, 2-H, 3-H, 5-H, 6-H), 2.04 (s, 2H, OH), 1.60 (s,
2H, CH ): δ = 131.9 (+, C2, C3, C5,
) ppm. 13C NMR (100 MHz, CDCl
C6), 122.5 (o, C1, C4), 95.5 (CCOH), 81.6 (CCCOH), 65.4 (COH), 31.4 (+,
According
to
0
3
)
2
2
Conclusions
3
3
1
3
3
The phenomena of conjugation and cross-conjugation are well
reflected in the properties of dicationic salts which were prepared
as model compounds for conjugation/conjugation, cross-
conjugation/cross-conjugation as well as conjugation/cross-
conjugation combinations. The types of conjugation can well be
differentiated by means of 13C NMR, IR, Raman, and UV/Vis
spectroscopy.
CH
3
) ppm. IR (ATR): 3332, 2980, 2931, 1507, 1460, 1441, 1396, 1361,
-1
1272, 1187, 1141, 959, 904, 846, 835, 789, 588, 562, 469 cm .
Spectroscopic data are in agreement with those reported in the literature.
[
24]
General procedure of synthesis of the terminal alkynes (Procedure
): The reactions were carried out under a nitrogen atmosphere. A flask
was charged with the protected acetylenes (1.00 mmol), KOH (1.05 mmol),
PO (1.05 mmol), and anhydrous toluene (40 mL). Then the flask was
2
K
3
4
Experimental Section
immersed into a preheated oil bath (200 °C). The suspensions were stirred
vigorously under reflux temperature until complete conversion, as
monitored by TLC. The mixtures were then allowed to cool to rt and filtered
through a plug of celite, which was washed several times with toluene.
After evaporation of the organic phase to dryness, the resulting residues
were finally purified by column chromatography (petroleum ether: ethyl
acetate) to afford the products.
All reactions were carried out under an atmosphere of nitrogen in flame or
oven-dried glassware. All chemicals were purchased and used without
further purification unless otherwise mentioned. Anhydrous solvents were
dried according to standard procedures before usage. Melting points are
uncorrected and were determined in an apparatus according to Dr. Tottoli
(
Büchi). The ATR-IR spectra were obtained on a Bruker Alpha in the range
of 400 to 4000 cm . 1H NMR spectra were recorded at 400 MHz or 600
MHz. 13C NMR spectra were recorded at 100 MHz or 150 MHz, with the
solvent peak used as the internal reference. Multiplicities are described by
using the following abbreviations: s = singlet, d = doublet, t = triplet, q =
quartet, and m = multiplet. Signal orientations in DEPT experiments were
-1
1
,4-Diethynylbenzene (8): According to Procedure 2, a solution of 3.630
g (15.00 mmol) of 4,4'-benzene-1,4-diylbis(2-methylbut-3-yn-2-ol) 7, 0.882
g (15.75 mmol) of KOH and 3.339 g (15.75 mmol) of K PO in 50 mL of
3
4
anhydrous toluene was heated (0.25 h) under reflux temperature. Finally,
a purification by column chromatography (petroleum ether: ethyl acetate =
3 2
described as follows: o = no signal; + = up (CH, CH ); - = down (CH ). The
3
9
3
:1) gave 1,4-diethynylbenzene 8. Yield 1.603 g, 62%, a white solid m.p.
electrospray ionization mass spectra (ESIMS) were measured with a
Bruker Impact-II mass spectrometer. Samples were sprayed from MeCN.
Chromatography: The reactions were traced by thin layer chromatography
with silica gel 60 (F254, MERCK KGAA). For the detection of substances,
quenching was used at either 254 nm or 366 nm with a mercury lamp. The
preparative column chromatography was conducted through silica gel 60
1
3-94 °C. H NMR (400 MHz, CDCl
3
): δ = 7.44 (s, 4H, 2-H, 3-H, 5-H, 6-H),
.17 (s, 2H, CCH) ppm. 13C NMR (100 MHz, CDCl
3
): δ = 132.0 (+, C2, C3,
C5, C6), 122.5 (o, C1, C4), 83.0 (o, CCH), 79.1 (o, CCH) ppm. IR (ATR):
3
260, 2104, 1919, 1668, 1506, 1495, 1404, 1368, 1251, 1170, 1105, 1016,
-
1
9
64, 905, 833, 675, 620, 545, 492 cm . Spectroscopic data are in
agreement with those reported in the literature. [
25]
(230 - 400 mesh).
3
-((4-Ethynylphenyl)ethynyl)quinoline (9): According to Procedure 1, a
solution of 2.080 g (10.00 mmol) of 3-bromoquinoline, 0.070 g (0.10 mmol)
of Pd(PPh Cl , 0.038 g (0.20 mmol) of CuI, and 1.197 g (9.50 mmol) of
,4-diethynylbenzene 8 in 50 mL of anhydrous NEt was heated (3.5 h)
under reflux temperature. Finally, a purification by column chromatography
Calculations: All density-functional theory (DFT)-calculations were carried
out by using the Firefly 8.2.0 QC package[21], which is partially based on
the GAMESS (US)[22] source code, running on Linux 2.6.18-238.el5 SMP
3
)
2
2
1
3
(
(
x86_64) on five AMD Phenom II X6 1090T processor workstations
Beowulf-cluster) with Infiniband interconnect and parallelized with MPICH
(petroleum ether: ethyl acetate = 3:1) gave compound 9. Yield 0.889 g,
1
.2.7p1. MM2 optimized structures were used as starting geometries.
Complete geometry optimizations were carried out on the implemented 6-
1G* basis set and with the PBE0 density functional. All calculated
1
37%, a brown solid, m.p. 113-114 °C. H NMR (600 MHz, CDCl
3
): δ = 8.99
(d, J = 2.1 Hz, 1H, 2-H), 8.30 (d, J = 2.1 Hz, 1H, 4-H), 8.10 (d, J = 8.5 Hz,
3
1
H, 8-H), 7.70 (d, J = 8.1 Hz, 1H, 5-H), 7.73 (ddd, J = 1.5, 7.0, 8.5 Hz, 1H,
-H), 7.57 (ddd, J = 1.5, 7.0, 8.1 Hz, 1H, 6-H), 7.55-7.53 (m, 2H, 2ʹ-H, 6ʹ-
structures were proven to be true minima by the absence of imaginary
frequencies. UV/Vis transitions were obtained by time dependent (TD)-
7
H), 7.51-7.49 (m, 2H, 3ʹ-H, 5ʹ-H), 3.20 (s, 1H, CCH) ppm. 13C NMR (150
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European Journal of Organic Chemistry
10.1002/ejoc.201900816
FULL PAPER
MHz, CDCl
3
): δ = 152.1 (+, C2), 147.1 (o, C8a), 138.5 (+, C4), 132.3 (+,
7.9 Hz, 2H, 7-H, 7ʹ-H), 7.66 (s, 4H, 2ʹʹ-H, 3ʹʹ-H, 5ʹʹ-H, 6ʹʹ-H), 7.60 (d, J = 8.1
Hz, 3-H, 3ʹ-H), 7.55 (ddd, J = 1.4, 6.8, 8.1 Hz, 2H, 6-H, 6ʹ-H) ppm. 13C NMR
C3ʹ, C5ʹ), 131.7 (+, C2ʹ, C6ʹ), 130.4 (+, C7), 129.6 (+, C8), 127.8 (+, C5),
1
9
3
1
4
2
27.5 (+, C6), 127.4 (o, C4a), 123.2 (o, C1ʹ), 122.6 (o, C4ʹ), 117.2 (o, C3),
2.1 (o, C), 88.7 (o, C), 83.2 (o, C), 79.4 (o, C) ppm. IR (ATR): 3265,
060, 3034, 2101, 1969, 1710, 1699, 1602, 1566, 1487, 1404, 1351, 1266,
145, 1105, 1010, 981, 958, 906, 861, 838, 782, 752, 691, 653, 622, 548,
3
(150 MHz, CDCl ): δ = 148.3 (o, C8a, C8aʹ), 143.3 (o, C2, C2ʹ), 136.3 (+,
C4, C4ʹ), 132.2 (+, C2ʹʹ, C3ʹʹ, C5ʹʹ, C6ʹʹ), 130.2 (+, C7, C7ʹ), 129.4 (+, C8,
C8ʹ), 127.6 (+, C5, C5ʹ), 127.3 (+, C6, C6ʹ), 127.2 (o, C4a, C4aʹ), 124.4 (+,
C3, C3ʹ), 122.9 (o, C1ʹʹ, C4ʹʹ), 91.4 (o, C, C), 89.3 (o, C, C) ppm. IR
-
1
+
71, 419 cm . HRMS (ESI): m/z calcd for C19
H12N [M+H] 254.0964, found
(ATR): 3056, 2211, 2186, 1590, 1548, 1505, 1419, 1289, 1107, 971, 950,
+
-1
54.0972; m/z calcd for C19H11NNa [M+Na] 276.0789, found 276.0785.
830, 790, 748, 629, 555, 480 cm . HRMS (ESI): m/z calcd for C28
[
H N
16 2
+
M+H] 381.1386, found 381.1390.
2-((4-(Quinolin-3-ylethynyl)phenyl)ethynyl)quinoline (10a): According
to Procedure 1, a solution of 0.017 g (0.11 mmol) of 2-chloroquinoline,
3,3'-(Benzene-1,4-diyldiethyne-2,1-diyl)diquinoline (10d): According to
0
0
.007 g (0.01 mmol) of Pd(PPh
.030 g (0.12 mmol) of 3-((4-ethynylphenyl)ethynyl)quinoline in 10 mL of
was heated for 3.5 h under reflux temperature. Finally, a
purification by column chromatography (petroleum ether: ethyl acetate =
3
)
2
Cl
2
, 0.0038 g (0.02 mmol) of CuI, and
Procedure 1, a solution of 0.520 g (2.50 mmol) of 3-bromoquinoline, 0.070
g (0.10 mmol) of Pd(PPh
mmol) of 1,4-diethynylbenzene in 10 mL of anhydrous NEt
3.5 under reflux temperature. Finally, purification by column
chromatography (petroleum ether: ethyl acetate 3:1) gave 3,3'-
compound 10d. Yield 0.095 g, 25%, a yellow solid, m.p. 203-204 °C. 1H
NMR (600 MHz, CDCl ): δ = 9.00 (d, J = 2.0 Hz, 2H, 2-H, 2ʹ-H), 8.32 (d, J
3
)
2
Cl
2
, 0.038 g (0.20 mmol) CuI, and 0.126 g (1.00
anhydrous NEt
3
3
was heated for
h
a
3:1) gave compound 10a. Yield 0.035 g, 80%, a yellow solid, m.p. 197-
=
1
198 °C. H NMR (600 MHz, CDCl
3
): δ = 9.01 (s, 1H, 2-H), 8.32 (d, J = 1.9
Hz, 1H, 4-H), 8.16-8.13 (m, 2H, 4ʹ-H, 8ʹ-H), 7.81-7.80 (m, 2H, 5-H, 5ʹ-H),
3
7
.76-7.72 (m, 2H, 7-H, 7ʹ-H), 7.68-7.67 (m, 2H, 3ʹʹ-H, 5ʹʹ-H), 7.61 (d, J =
= 2.0 Hz, 2H, 4-H, 4ʹ-H), 8.11 (d, J = 8.1 Hz, 2H, 8-H, 8ʹ-H), 7.81 (d, J =
7.7 Hz, 2H, 5-H, 5ʹ-H), 7.73 (ddd, J = 1.5, 7.0, 8.1 Hz, 2H, 7-H, 7ʹ-H), 7.60
(s, 4H, 2ʹʹ-H, 3ʹʹ-H, 5ʹʹ-H, 6ʹʹ-H), 7.58 (ddd, J = 1.5, 7.0. 7.7 Hz, 2H, 6-H, 6ʹ-
8
.5 Hz, 1H, 3ʹ-H), 7.60-7.59 (m, 2H, 2ʹʹ-H, 6ʹʹ-H), 7.58-7.54 (m, 2H, 6-H, 6ʹ-
H) ppm. 13C NMR (150 MHz, CDCl
): δ = 152.1 (+, C2), 148.4 (o, C8aʹ),
47.0 (o, C8a), 143.4 (o, C2ʹ), 138.6 (+, C4), 136.4 (+, C4ʹ), 132.4 (+, C3ʹʹ,
C5ʹʹ), 131.9 (+, C2ʹʹ, C6ʹʹ), 130.4 (+, C7), 130.3 (+, C7ʹ), 129.54 (+, C8),
29.49 (+, C8ʹ), 127.8 (+, C5), 127.7 (+, C5ʹ), 127.5 (+, C6), 127.41 (+,
C6ʹ), 127.37 (o, C4a), 127.3 (o, C4aʹ), 124.5 (+, C3ʹ), 123.5 (o, C1ʹʹ), 122.6
o, C4ʹʹ), 117.3 (o, C3), 92.3 (o, C), 91.4 (o, C), 89.4 (o, C), 89.0 (o, C)
ppm. IR (ATR): 3051, 3037, 2958, 2922, 2851, 2210, 1738, 1733, 1615,
3
1
H) ppm. 13C NMR (150 MHz, CDCl
3
): δ = 152.1 (+, C2, C2ʹ), 147.1 (o, C8a,
C8aʹ), 138.5 (+, C4, C4ʹ), 131.9 (+, C2ʹʹ, C3ʹʹ, C5ʹʹ, C6ʹʹ), 130.4 (+, C7, C7ʹ),
129.6 (+, C8, C8ʹ), 127.8 (+, C5, C5ʹ), 127.5 (+, C6, C6ʹ), 127.4 (o, C4a,
C4aʹ), 123.1 (o, C1ʹʹ, C4ʹʹ), 117.3 (o, C3, C3ʹ), 92.3 (o, C, C), 88.9 (o, C,
C) ppm. IR (ATR): 3066, 3055, 3016, 1838, 1567, 1486, 1354, 1101, 981,
1
(
-
958, 906, 863, 830, 785, 746, 641, 620, 569, 547, 516, 474, 459, 432 cm
1. HRMS (ESI): m/z calcd for C28
H N
16 2
[M+H] 381.1386, found 381.1387.
+
1
1
5
3
593, 1550, 1488, 1460, 1405, 1352, 1342, 1306, 1288, 1242, 1158, 1115,
106, 1046, 1012, 980, 955, 912, 871, 850, 828, 790, 748, 693, 626, 613,
[M+H]+
16 2
52, 520, 472, 429 cm . HRMS (ESI): m/z calcd for C28H N
-
1
4
,4'-(Benzene-1,4-diyldiethyne-2,1-diyl)diquinoline (10e): According to
Procedure 1, a solution of 0.520 g (2.50 mmol) of 4-bromoquinoline, 0.070
g (0.10 mmol) of Pd(PPh Cl , 0.038 g (0.20 mmol) CuI, and 0.126 g (1.00
mmol) of 1,4-diethynylbenzene in 10 mL of anhydrous NEt was heated
81.1386, found 381.1382.
3
)
2
2
3-((4-(Quinolin-4-ylethynyl)phenyl)ethynyl)quinoline (10b): According
3
to Procedure 1, a solution of 0.208 g (1.00 mmol) of 4-bromoquinoline,
(3.5 h) under reflux temperature. Finally, a purification by column
chromatography (petroleum ether: ethyl acetate = 3:1) gave compound
10e. Yield 0.103 g, 27%, an orange solid, m.p. 225-226 °C (decomp.). H
0
0
.070 g (0.10 mmol) of Pd(PPh
.278 g (1.10 mmol) of 3-((4-ethynylphenyl)ethynyl)quinoline in 25 mL of
was heated for 3.5 h under reflux temperature. Finally, a
purification by column chromatography (petroleum ether: ethyl acetate =
3 2 2
) Cl , 0.038 g (0.20 mmol) of CuI, and
1
anhydrous NEt
3
3
NMR (600 MHz, CDCl ): δ = 8.93 (d, J = 4.4 Hz, 2H, 2-H, 2ʹ-H), 8.37 (ddd,
J = 0.5, 1.4, 8.3 Hz, 2H, 5-H, 5ʹ-H), 8.15 (ddd, J = 0.5, 1.3, 8.5 Hz, 2H, 8-
H, 8ʹ-H), 7.79 (ddd, J = 1.3, 6.9, 8.4 Hz, 2H, 7-H, 7ʹ-H), 7.72 (s, 4H, 2ʹʹ-H,
3ʹʹ-H, 5ʹʹ-H, 6ʹʹ-H), 7.67 (ddd, J = 1.3, 6.9, 8.4 Hz, 2H, 6-H, 6ʹ-H), 7.59 (d, J
3
:1) gave compound 10b. Yield 0.228 g, 61%, a yellow solid, m.p. 153-
1
154 °C. H NMR (600 MHz, CDCl
3
): δ = 9.02 (d, J = 2.1 Hz, 1H, 2-H), 8.92
(
8
d, J = 4.3 Hz, 1H, 2-Hʹ), 8.37 (d, J = 8.3 Hz, 1H, 5ʹ-H), 8.33 (s, 1H, 4-H),
.16 (d, J = 8.1 Hz, 1H, 8ʹ-H), 8.12 (d, J = 8.5 Hz, 1H, 8-H), 7.81 (d, J = 7.9
Hz, 1H, 5-H), 7.80-7.77 (m, 1H, 7ʹ-H), 7.76-7.73 (m, 1H, 7-H), 7.68 (d, J =
= 4.4 Hz, 2H, 3-H, 3ʹ-H) ppm. 13C NMR (150 MHz, CDCl
3
): δ = 149.9 (+,
C2, C2ʹ), 148.3 (o, C8a, C8aʹ), 132.2 (+, C2ʹʹ, C3ʹʹ, C5ʹʹ, C6ʹʹ), 130.2 (+, C8,
C8ʹ), 130.1 (+, C7, C7ʹ), 129.4 (o, C4, C4ʹ), 127.7 (o, C4a, C4aʹ), 127.5 (+,
C6, C6ʹ), 126.0 (+, C5, C5ʹ), 123.8 (+, C3, C3ʹ), 123.3 (o, C1ʹʹ, C4ʹʹ), 98.0
(o, C, C), 87.5 (o, C, C) ppm. IR (ATR): 2981, 1733, 1576, 1561, 1506,
1495, 1461, 1435, 1389, 1361, 1272, 1154, 1134, 1102, 1027, 961, 904,
8
2
.3 Hz, 2H, 3ʹʹ-H, 5ʹʹ-H), 7,67-7.65 (m, 1H, 6ʹ-H), 7.64 (d, J = 8.3 Hz, 2H,
ʹʹ-H, 6ʹʹ-H), 7.60-7.57 (m, 2H, 6-H, 3ʹ-H) ppm. 13C NMR (150 MHz, CDCl
):
3
δ = 152.1 (+, C2), 149.7 (+, C2ʹ), 148.0 (o, C8aʹ), 147.1 (o, C8a), 138.6 (+,
C4), 132.2 (+, C3ʹʹ, C5ʹʹ), 132.0 (+, C2ʹʹ, C6ʹʹ), 130.5 (+, C7), 130.3 (+, C7ʹ),
-
1
868, 846, 759, 722, 691, 642, 625, 571, 547, 470, 442 cm . HRMS (ESI):
+
129.9 (+, C8ʹ), 129.7 (o, C4ʹ), 129.6 (+, C8), 127.81 (+, C5), 127.76 (o,
m/z calcd for C28H N
16 2
[M+H] 381.1386, found 381.1390.
C4aʹ), 127.57 (+, C6), 127.54 (+, C6ʹ), 127.36 (o, C4a), 126.1 (+, C5),
1
9
1
23.78 (o, C1ʹʹ), 123.75 (+, C3ʹ), 122.6 (o, C4ʹʹ), 117.2 (o, C3), 98.4 (o, C),
2.2 (o, C), 89.3 (o, C), 87.2 (o, C) ppm. IR (ATR): 3033, 2210, 2188,
733, 1575, 1511, 1486, 1462, 1418, 1393, 1351, 1294, 1194, 1101, 1012,
General procedure for the preparation of the salts 11a-e (Procedure
): Samples of 0.50 mmol of the corresponding quinolines 10a-e were
dissolved in toluene containing 1 drop of nitrobenzene. Then an excess of
dimethyl sulfate was added with stirring. Thereafter the resulting mixture
was stirred under reflux temperature. After completion of the reaction
3
-
9
81, 954, 906, 864, 829, 782, 746, 678, 641, 592, 543, 476, 463, 419 cm
1
+
.
HRMS (ESI): m/z calcd for C28
H N
16 2
[M+H] 381.1386, found 381.1384.
(controlled by TLC), the solution was cooled, the crude product was filtered
2
,2'-(Benzene-1,4-diyldiethyne-2,1-diyl)diquinoline (10c): According to
Procedure 1, a solution of 0.408 g (2.50 mmol) of 2-chloroquinoline, 0.070
g (0.10 mmol) of Pd(PPh Cl , 0.038 g (0.20 mmol) of CuI and 0.126 g
1.00 mmol) of 1,4-diethynylbenzene in 10 mL of anhydrous NEt was
off, washed with ethyl acetate (3 × 10 mL), and dried to afford the products.
3
)
2
2
1
-Methyl-2-((4-((1-methylquinolinium-3-
yl)ethynyl)phenyl)ethynyl)quinolinium
According to Procedure 3, a solution of 0.048 g (0.125 mmol) of 2-((4-
quinolin-3-ylethynyl)phenyl)ethynyl)quinoline 10a, 1 drop of nitrobenzene
(
3
dimethylsulfate
(11a):
heated (3.5 h) under reflux temperature. Finally, a purification by column
chromatography (petroleum ether: ethyl acetate = 3:1) gave compound
(
1
0c. Yield 0.209 g, 55%, a yellow solid, m.p. 207-208 °C. 1H NMR (600
and 0.06 mL (0.63 mmol) of dimethyl sulfate in 5 mL of anhydrous toluene
was heated over the period of 3 h under reflux temperature to give
compound 11a. Yield 0.078 g, 99%, a yellow solid, m.p. 205-206 °C
MHz, CDCl
3
): δ = 8.17 (d, J = 8.1 Hz, 2H, 4-H, 4ʹ-H), 8.13 (d, J = 7.9 Hz,
2H, 8-H, 8ʹ-H), 7.80 (d, J = 8.1 Hz, 2H, 5-H, 5ʹ-H), 7.74 (ddd, J = 1.4, 6.8,
This article is protected by copyright. All rights reserved.

European Journal of Organic Chemistry
10.1002/ejoc.201900816
FULL PAPER
1
(
decomp.). H NMR (600 MHz, [D
6
]DMSO): δ = 9.91 (d, J = 0.9 Hz, 1H, 2-
drop of nitrobenzene, and 0.06 mL (0.63 mmol) of dimethyl sulfate in 5 mL
of anhydrous toluene was heated for 3 h under reflux temperature to give
11d. Yield 0.078 g, 99%, a yellow solid, m.p. 265 °C (decomp.). H NMR
H), 9.55 (s, 1H, 4-H), 9.26 (d, J = 8.6 Hz, 1H, 4ʹ-H), 8.62 (d, J = 8.9 Hz, 1H,
ʹ-H), 8.56 (d, J = 9.0 Hz, 1H, 8-H), 8.48-8.46 (m, 3H, 5-H, 3ʹ-H, 5ʹ-H), 8.36-
1
8
8.31 (m, 2H, 7-H, 7ʹ-H), 8.14-8.11 (m, 3H, 6-H, 3ʹʹ-H, 5ʹʹ-H), 8.07 (t, J = 7.6
6
(600 MHz, [D ]DMSO): δ = 9.89 (d, J = 1.0 Hz, 2H, 2-H, 2ʹ-H), 9.53 (s, 2H,
Hz, 1H, 6ʹ-H), 7.91 (d, J = 8.4 Hz, 2H, 2ʹʹ-H, 6ʹʹ-H), 4.80 (s, 3H, NʹCH
.67 (s, 3H, NCH ), 3.37 (s, 6H, 2 CH SO
) ppm. 13C NMR (150 MHz,
]DMSO): δ = 152.2 (+, C2), 148.3 (+, C4), 145.6 (+, C4ʹ), 140.2 (o, C2ʹ),
39.4 (o, C8aʹ), 137.5 (o, C8a), 136.4 (+, C7), 136.2 (+, C7ʹ), 133.6 (+, C3ʹʹ,
3
),
4-H, 4ʹ-H), 8.55 (d, J = 8.9 Hz, 2H, 8-H, 8ʹ-H), 8.47 (d, J = 7.5 Hz, 2H, 5-H,
5ʹ-H), 8.33 (ddd, J = 1.6, 7.1, 8.7 Hz, 2H, 7-H, 7ʹ-H), 8.11 (t, J = 7.9 Hz, 2H,
4
3
3
4
[
D
6
6-H, 6ʹ-H), 7.83 (s, 4H, 2ʹʹ-H, 3ʹʹ-H, 5ʹʹ-H, 6ʹʹ-H), 4.67 (s, 6H, 2NCH
3
), 3.37
1
(s, 6H, 2 CH SO ]DMSO): δ = 152.2 (+, C2,
3
4
) ppm. 13C NMR (150 MHz, [D
6
C5ʹʹ), 132.4 (+, C2ʹʹ, C6ʹʹ), 130.7 (+, C6), 130.44 (+, C5 or C5ʹ), 130.37 (+,
C5 or C5ʹ), 130.2 (+, C6ʹ), 128.7 (o, C4a), 128.6 (o, C4aʹ), 126.3 (+, C3ʹ),
C2ʹ), 148.2 (+, C4, C4ʹ), 137.4 (o, C8a, C8aʹ), 136.3 (+, C7, C7ʹ), 132.3 (+,
C2ʹʹ, C3ʹʹ, C5ʹʹ, C6ʹʹ), 130.7 (+, C6, C6ʹ), 130.4 (+, C5, C5ʹ) 128.7 (o, C4a,
C4aʹ), 122.1 (o, C1ʹʹ, C4ʹʹ), 119.3 (+, C8, C8ʹ), 116.4 (o, C3, C3ʹ), 93.9 (o,
1
1
4
1
7
24.1 (o, C1ʹ), 120.1 (o, C4ʹ), 119.6 (+, C8ʹ), 119.3 (+, C8), 116.2 (o, C3),
07.1 (o, C), 93.6 (o, C), 86.8 (o, C), 84.6 (o, C), 52.8 (+, 2 CH SO ),
5.5 (+, NCH ), 42.9 (+, NʹCH ) ppm. IR (ATR): 3049, 2200, 1594, 1575,
520, 1455, 1437, 1408, 1377, 1354, 1307, 1216, 1155, 1056, 1001, 838,
3
4
3 4 3 3
C, C), 85.8 (o, C, C),52.8 (+, 2 CH SO ), 45.5 (+, NCH , NʹCH ) ppm.
3
3
IR (ATR): 3045, 2219, 1629, 1605, 1580, 1520, 1448, 1378, 1358, 1214,
-
1
1168, 1140, 1057, 1002, 920, 846, 773, 733, 609, 576, 552, 432 cm .
HRMS (ESI): m/z calcd for C30
[M]2+ 205.0884, found 205.0881.
-
1
35, 609, 577, 552, 497, 429 cm . HRMS (ESI): m/z calcd for C30
H N
22 2
22 2
H N
[
M]2+ 205.0884, found 205.0886.
4,4'-(Benzene-1,4-diyldiethyne-2,1-diyl)bis(1-methylquinolinium)
1
-Methyl-3-((4-((1-methylquinolinium-4-
yl)ethynyl)phenyl)ethynyl))quinolinium
According to Procedure 3, a solution of 0.048 g (0.125 mmol) of 3-((4-
quinolin-4-ylethynyl)phenyl)ethynyl)quinoline 10b, 1 drop of nitrobenzene
dimethylsulfate (11e): According to Procedure 3, a solution of 0.048 g
(0.125 mmol) of 4,4'-(benzene-1,4-diyldiethyne-2,1-diyl)diquinoline 10e, 1
drop of nitrobenzene, and 0.06 mL (0.63 mmol) of dimethyl sulfate in 5 mL
of anhydrous toluene was heated for 3 h under reflux temperature to give
dimethylsulfate
(11b):
(
and 0.06 mL (0.63 mmol) of dimethyl sulfate in 5 mL of anhydrous toluene
was heated over the period of 3 h under reflux temperature to give
11e. Yield 0.075 g, 93%, a yellow solid, m.p. 218-219 °C (decomp.). 1
NMR (600 MHz, [D ]DMSO): δ = 9.52 (d, J = 6.0 Hz, 2H, 2-H, 2-Hʹ), 8.80
H
6
compound 11b. Yield 0.078 g, 99%, a yellow solid, m.p. 259-260 °C
(d, J = 8.3 Hz, 2H, 5-H, 5ʹ-H), 8.57 (d, J = 8.8 Hz, 2H, 8-H, 8ʹ-H), 8.40 (d,
J = 6.0 Hz, 2H, 3-H, 3ʹ-H), 8.35 (t, J = 7.8 Hz, 2H, 7-H, 7ʹ-H), 8.16 (t, J =
7.5 Hz, 2H, 6-H, 6ʹ-H), 8.12 (s, 4H, 2ʹʹ-H, 3ʹʹ-H, 5ʹʹ-H, 6ʹʹ-H), 4.64 (s, 6H,
1
6
(decomp.). H NMR (600 MHz, [D ]DMSO): δ = 9.91 (d, J = 1.0 Hz, 1H, 2-
H), 9.55 (s, 1H, 4-H), 9.53 (d, J = 6.4 Hz, 1H, 2ʹ-H), 8.81 (d, J = 9.0 Hz, 1H,
ʹ-H), 8.58 (d, J = 9.0 Hz, 1H, 8ʹ-H), 8.56 (d, J = 9.0 Hz, 1H, 8-H), 8.47 (d,
J = 7.8 Hz, 1H, 5-H), 8.37-8.32 (m, 2H, 7-H, 7ʹ-H), 8.17 (t, J = 7.5 Hz, 1H,
3 3 3 4
, NʹCH ), 3.38 (s, 6H, 2 CH SO
) ppm. 13C NMR (150 MHz,
5
NCH
[D ]DMSO): δ = 149.5 (+, C2, C2ʹ), 138.4 (o, C8a, C8aʹ), 137.8 (o, C4, C4ʹ),
6
6
7
3
ʹ-H), 8.12 (t, J = 7.5 Hz, 1H, 6-H), 8.09 (d, J = 8.3 Hz, 2H, 3ʹʹ-H, 5ʹʹ-H),
.89 (d, J = 8.3 Hz, 2H, 2ʹʹ-H, 6ʹʹ-H), 4.67 (s, 3H, NCH ), 4.64 (s, 3H, NʹCH ),
.37 (s, 6H, 2 CH SO ]DMSO): δ = 152.2
) ppm. 13C NMR (150 MHz, [D
135.8 (+, C7, C7ʹ), 133.4 (+, C2ʹʹ, C3ʹʹ, C5ʹʹ, C6ʹʹ), 130.9 (+, C6, C6ʹ), 128.3
(+, C5, C5ʹ), 127.9 (o, C4a, C4aʹ), 124.6 (+, C3, C3ʹ), 122.5 (o, C1ʹʹ, C4ʹʹ),
119.8 (+, C8a, C8aʹ), 105.6 (o, C, C), 86.6 (o, C, C), 52.8 (+, 2
3
3
3
4
6
(
(
+, C2), 149.5 (+, C2ʹ), 148.3 (+, C4), 138.4 (o, C8aʹ), 138.0 (o, C4ʹ), 137.5
o, C8a), 136.3 (+, C7), 135.8 (+, C7ʹ), 133.4 (+, C3ʹʹ, C5ʹʹ), 132.3 (+, C2ʹʹ,
CH
3 4 3 3
SO ), 45.5 (+, NCH , NʹCH ) ppm. IR (ATR): 3067, 3015, 2948, 2207,
1601, 1565, 1528, 1401, 1371, 1325, 1216, 1149, 1120, 1110, 1055, 994,
856, 807, 775, 738, 708, 646, 608, 577, 553, 488, 429 cm . HRMS (ESI):
m/z calcd for C30
[M]2+ 205.0884, found 205.0885.
-
1
C6ʹʹ), 130.9 (+, C6ʹ), 130.7 (+, C6), 130.4 (+, C5), 128.7 (o, C4a), 128.4 (o,
C4aʹ), 127.9 (+, C5ʹ), 124.4 (+, C3ʹ), 123.3 (o, C1ʹʹ), 121.3 (o, C4ʹʹ), 119.9
22 2
H N
(
+, C8ʹ), 119.3 (+, C8), 116.3 (o, C3), 105.8 (o, C), 93.8 (o, C), 86.4 (o,
C), 86.2 (o, C), 52.8 (+, 2 CH SO ), 45.5 (+, NCH ), 45.4 (+, NʹCH ) ppm.
IR (ATR): 3083, 3049, 2945, 2203, 2162, 1604, 1569, 1520, 1405, 1372,
3
4
3
3
General procedure of anion exchange to hexafluorophosphate
Procedure 4): The corresponding salt was dissolved in water, then
NH PF (1.05 equiv) in water was added whereupon the
(
1
5
2
326, 1244, 1226, 1214, 1058, 1011, 904, 844, 771, 737, 609, 575, 552,
4
6
-
1
22 2
00, 486, 465, 430 cm . HRMS (ESI): m/z calcd for C30H N
[M]2+
hexafluorophosphate salt precipitated immediately. After 0.5 h the crude
product was filtered off and washed with water (3 × 30 mL) and ethyl
acetate (3 × 30 mL), and dried in vacuo. The assignment of atoms in H/13C
was performed according to compounds with methylsulfate anion (11c-e).
05.0884, found 205.0885.
1
2,2'-(Benzene-1,4-diyldiethyne-2,1-diyl)bis(1-methylquinolinium)
dimethylsulfate (11c): According to Procedure 3, a solution of 0.048 g
0.125 mmol) of 2,2'-(benzene-1,4-diyldiethyne-2,1-diyl)diquinoline 10c, 1
drop of nitrobenzene, and 0.06 mL (0.63 mmol) of dimethyl sulfate in 5 mL
(
2
,2'-(Benzene-1,4-diyldiethyne-2,1-diyl)bis(1-methylquinolinium)
dihexafluorophosphate (11c2PF ): According to Procedure 4, a solution
of 0.045 g (0.071 mmol) of 11c and 0.024 g (0.149 mmol) of NH PF in 4
mL of water mixture was stirred over the period of 0.5 h at rt to give
. Yield 0.049 g, 98%, a yellow solid, m.p. 226-227 °C. 1H NMR
1c2PF
600 MHz, [D ]DMSO): δ = 9.28 (d, J = 8.6 Hz, 2H, 4-H, 4ʹ-H), 8.63 (d, J =
,8 Hz, 2H, 8-H, 8ʹ-H), 8.49 (d, J = 8.3 Hz, 2H, 3-H, 3ʹ-H), 8.48 (d, J = 7.5
Hz, 2H, 5-H, 5ʹ-H), 8.33 (t, J = 7,7 Hz, 2H, 7-H, 7ʹ-H), 8.19 (s, 4H, 2ʹʹ-H, 3ʹʹ-
6
of anhydrous toluene was heated for 3 h under reflux temperature to give
4
6
1
1
1c. Yield 0.079 g, 99%, a yellow solid m.p. 241-242 °C (decomp). H NMR
6
(600 MHz, [D ]DMSO): δ = 9.28 (d, J = 8.6 Hz, 2H, 4-H, 4ʹ-H), 8.63 (d, J =
1
(
8
6
8,8 Hz, 2H, 8-H, 8ʹ-H), 8.49 (d, J = 8.3 Hz, 2H, 3-H, 3ʹ-H), 8.48 (d, J = 7.5
6
Hz, 2H, 5-H, 5ʹ-H), 8.33 (t, J = 7,7 Hz, 2H, 7-H, 7ʹ-H), 8.19 (s, 4H, 2ʹʹ-H, 3ʹʹ-
H, 5ʹʹ-H, 6ʹʹ-H), 8.07 (t, J = 7.5 Hz, 2H, 6-H, 6ʹ-H), 4.81 (s, 6H, NCH ), 3.37
s, 6H, 2 CH SO ]DMSO): δ = 145.7 (+, C4,
) ppm. 13C NMR (150 MHz, [D
3
(
3
4
6
H, 5ʹʹ-H, 6ʹʹ-H), 8.07 (t, J = 7.5 Hz, 2H, 6-H, 6ʹ-H), 4.81 (s, 6H, 2NCH
13C NMR (150 MHz, [D
3
) ppm.
C4ʹ), 140.3 (o, C2, C2ʹ), 139.4 (o, C8a, C8aʹ), 136.2 (+, C7, C7ʹ), 133.6 (+,
C2ʹʹ, C3ʹʹ, C5ʹʹ, C6ʹʹ), 130.4 (+, C5, C5ʹ), 130.2 (+, C6, C6ʹ), 128.7 (o, C4a,
C4aʹ), 126.4 (+, C3, C3ʹ), 122.1 (o, C1ʹʹ, C4ʹʹ), 119.6 (+, C8, C8ʹ), 106.6 (o,
6
]DMSO): δ = 145.7 (C4, C4ʹ), 140.3 (C2, C2ʹ),
1
39.4 (C8a, C8aʹ), 136.2 (C7, C7ʹ), 133.6 (C2ʹʹ, C3ʹʹ, C5ʹʹ, C6ʹʹ), 130.4 (C5,
C5ʹ), 130.2 (C6, C6ʹ), 128.7 (C4a, C4aʹ), 126.4 (C3, C3ʹ), 122.1 (C1ʹʹ, C4ʹʹ),
19.6 (C8, C8ʹ), 106.6 (C, C), 85.1 (C, C), 43.0 (NCH , NʹCH ) ppm.
3 4 3 3
C, C), 85.1 (o, C, C), 52.8 (+, 2 CH SO ), 43.0 (+, NCH , NʹCH ) ppm.
1
3
3
IR (ATR): 3070, 2203, 1615, 1594, 1575, 1521, 1437, 1353, 1160, 1045,
IR (ATR): 3100, 2204, 2042, 1596, 1576, 1522, 1439, 1352, 1234, 1161,
-
1
1
000, 838, 744, 576, 553, 498, 476, 428 cm . HRMS (ESI): m/z calcd for
-1
1
[
059, 819, 602, 555, 499, 471 cm . HRMS (ESI): m/z calcd for C30
H N
22 2
[M]2+ 205.0884, found 205.0889.
30 22 2
C H N
M]2+ 205.0884, found 205.0881.
3
,3'-(Benzene-1,4-diyldiethyne-2,1-diyl)bis(1-methylquinolinium)
dimethylsulfate (11d): According to Procedure 3, a solution of 0.048 g
0.125 mmol) of 3,3'-(benzene-1,4-diyldiethyne-2,1-diyl)diquinoline 10d, 1
3
,3'-(Benzene-1,4-diyldiethyne-2,1-diyl)bis(1-methylquinolinium)
dihexafluorophosphate (11d2PF
of 0.020 g (0.031 mmol) of 11d and 0.011 g (0.065 mmol) of NH
6
): According to Procedure 4, a solution
PF in 4
(
4
6
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European Journal of Organic Chemistry
10.1002/ejoc.201900816
FULL PAPER
mL of water mixture was stirred over the period of 0.5 h at rt to give
Grace, H. Hopf, P. Klaeboe, F. Lehrich, C. J. Nielsen, D. L. Powell, M.
Traetteberg, Acta Chem. Scand. 1988, 42a, 634 − 650.
1
1d2PF
6
. Yield 0.021 g, 99%, a yellow solid, m.p. 224-225 °C. 1H NMR
(
600 MHz, [D
6
]DMSO): δ = 9.89 (d, J = 1.0 Hz, 2H, 2-H, 2ʹ-H), 9.53 (s, 2H,
-H, 4ʹ-H), 8.55 (d, J = 8.9 Hz, 2H, 8-H, 8ʹ-H), 8.47 (d, J = 7.5 Hz, 2H, 5-H,
ʹ-H), 8.33 (ddd, J = 1.6, 7.1, 8.7 Hz, 2H, 7-H, 7ʹ-H), 8.11 (t, J = 7.9 Hz, 2H,
-H, 6ʹ-H), 7.83 (s, 4H, 2ʹʹ-H, 3ʹʹ-H, 5ʹʹ-H, 6ʹʹ-H), 4.67 (s, 6H, NCH , NʹCH
]DMSO): δ = 152.2 (C2, C2ʹ), 148.2 (C4, C4ʹ),
37.4 (C8a, C8aʹ), 136.3 (C7, C7ʹ), 132.3 (C2ʹʹ, C3ʹʹ, C5ʹʹ, C6ʹʹ), 130.7 (C6,
C6ʹ), 128.7 (C4a, C4aʹ), 122.1 (C1ʹʹ, C4ʹʹ), 119.3 (C8, C8ʹ), 116.4 (C3, C3ʹ),
[6]
(a) D. T. Christiansen, A. L. Tomlinson, J. R. Reynolds, J. Am. Chem.
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Rahul, J. Sankar, Angew. Chem. Int. Ed. 2018, 57), 5052 – 5056. (c) A.
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K. Sugiyasu, R. Inoue, R. Shomura, Y. Matsushita, M. Takeuchi, Synlett
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4
5
6
3
3
)
ppm. 13C NMR (150 MHz, [D
[7]
[8]
6
1
9
2
7
3.9 (C, C), 85.8 (C, C), 45.5 (NCH
230, 1607, 1581, 1521, 1435, 1378, 1359, 1318, 1222, 1117, 926, 823,
67, 622, 555, 494, 483, 433 cm . HRMS (ESI): m/z calcd for C30H N
22 2
3 3
, NʹCH ) ppm. IR (ATR): 3095,
-
1
[
M]2+ 205.0884, found 205.0882.
[
[
9]
H. Hosoya, Bull. Chem. Soc. Jp. 2019, 92, 205 – 215.
4
,4'-(Benzene-1,4-diyldiethyne-2,1-diyl)bis(1-methylquinolinium)
10] (a) C. A Coulson, G. S. Rushbrooke, Proc. Camb. Phil. Soc. 1940, 36,
dihexafluorophosphate (11e2PF
6
): According to Procedure 4, a solution
PF in 4
mL of water mixture was stirred over the period of 0.5 h at rt to give
193 – 200. (b) C. A. Coulson, H. C. Longuet-Higgins, Proc. R. Soc.
of 0.020 g (0.031 mmol) of 11e and 0.011 g (0.065 mmol) of NH
4
6
London, Ser. A 1947, 191, 39. (c) C. A. Coulson, H. C. Longuet-Higgins,
Proc. R. Soc. London, Ser. A 1947, 192, 16. (d) H. C. Longuet-Higgins,
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Engl. 1965, 4, 1039 - 1050. (f) L. Salem, The Molecular Orbital Theory of
Conjugated Systems. Benjamin, New York (1966).
1
1e2PF
6
. Yield 0.021 g, 99%, a green solid, m.p. 341-342 °C (decomp.).
]DMSO): δ = 9.52 (d, J = 6.0 Hz, 2H, 2-H, 2-Hʹ),
.80 (d, J = 8.3 Hz, 2H, 5-H, 5ʹ-H), 8.57 (d, J = 8.8 Hz, 2H, 8-H, 8ʹ-H), 8.40
d, J = 6.0 Hz, 2H, 3-H, 3ʹ-H), 8.35 (t, J = 7.8 Hz, 2H, 7-H, 7ʹ-H), 8.16 (t, J
7.5 Hz, 2H, 6-H, 6ʹ-H), 8.12 (s, 4H, 2ʹʹ-H, 3ʹʹ-H, 5ʹʹ-H, 6ʹʹ-H), 4.64 (s, 6H,
NCH , NʹCH ]DMSO): δ = 149.5 (C2, C2ʹ),
) ppm. 13C NMR (150 MHz, [D
38.4 (C8a, C8aʹ), 137.8 (C4, C4ʹ), 135.8 (C7, C7ʹ), 133.4 (C2ʹʹ, C3ʹʹ, C5ʹʹ,
C6ʹʹ), 130.9 (C6, C6ʹ), 128.3 (C5, C5ʹ), 127.9 (C4a, C4aʹ), 124.6 (C3, C3ʹ),
22.5 (C1ʹʹ, C4ʹʹ), 119.8 (C8a, C8aʹ), 105.6 (C, C), 86.6 (C, C), 45.5
NCH , NʹCH ) ppm. IR (ATR): 3327, 3102, 2209, 2167, 1619, 1604, 1574,
530, 1508, 1436, 1403, 1373, 1335, 1326, 1237, 1204, 1179, 1155, 1116,
1
H NMR (600 MHz, [D
8
(
=
6
[
[
[
[
11] W. D. Ollis, S. P. Stanforth, C. A. Ramsden, Tetrahedron 1985, 41, 2239-
2329.
3
3
6
12] (a) A. Schmidt, Curr. Org. Chem. 2004, 8, 653 – 670. (b) A. Schmidt, Adv.
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1
13] A. Schmidt, M. K. Kindermann, M. Nieger, Heterocycles 1999, 51, 237 –
1
(
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3
14] C. A. Ramsden, Progr. Heterocycl. Chem. 2016, 28, 1 – 25.
1
1
-
1
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[M]2+ 205.0884, found 205.0886.
(ESI): m/z calcd for C30
H N
22 2
3
793.
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[
Keywords: quinolininium • charge distribution • mesomeric
betaines • polycations • hetarenium salts
2
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European Journal of Organic Chemistry
10.1002/ejoc.201900816
FULL PAPER
This article is protected by copyright. All rights reserved.

European Journal of Organic Chemistry
10.1002/ejoc.201900816
FULL PAPER
Entry for the Table of Contents
FULL PAPER
Series of diquinolinium salts
Conjugation vs. cross-conjugation in
salts
separated by spacers were prepared
which possess cationic charges in
conjugation and cross-conjugation as
well as combinations thereof. The
Sviatoslav Batsyts, Eike G. Hübner, Jan
C. Namyslo, and Andreas Schmidt*
1
3
spectroscopic differences ( C NMR,
IR, Raman, UV/Vis) of 2,2-, 3,3-, 4,4-,
Page No. – Page No.
The interconnection of two positive
charges by conjugation and cross-
conjugation in bis-quinolinium
ethynyls.
3,2- and 3,4-interconnections of
positive charges are studied
experimentally and by DFT
calculations.
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