Hydrophobic-Driven, Metallomacrocyclic Assembly - Towards Quantitative Construction

Article abstract of DOI:10.1002/ejic.201600048

A series of coordination-driven, heteroleptic self-assembled, bowtie-shaped bis-macrocycles were designed and constructed by combining tetrakis(terpyridinyl)thianthrene and bis-terpyridine, 60°-directed, Ru²⁺ dimers. The resulting complexes wer

Full text of DOI:10.1002/ejic.201600048

DOI: 10.1002/ejic.201600048
Full Paper
Metallomacrocycles
Hydrophobic-Driven, Metallomacrocyclic Assembly – Towards
Quantitative Construction
Ting-Zheng Xie,[a][‡] Jing-Yi Li,[a][‡] Zaihong Guo,[b] James M. Ludlow III,[a] Xiaocun Lu,[a]
Charles N. Moorefield,[a] Chrys Wesdemiotis,*[a,b] and George R. Newkome*[a,b]
Abstract: A series of coordination-driven, heteroleptic self-as- coupled with travelling wave ion mobility spectrometry (ESI-
sembled, bowtie-shaped bis-macrocycles were designed and TWIM-MS) experiments. The desired bis-macrocycles were ob-
constructed by combining tetrakis(terpyridinyl)thianthrene and tained in quantitative yields through the use of long alkyl-chain
bis-terpyridine, 60°-directed, Ru2+ dimers. The resulting com- substituents, in contrast to the lower yields obtained for smaller
plexes were characterized by NMR spectroscopy and ESI-MS alkyl moieties.
Introduction
lar (bowtie-shaped) macrocycles through the reactions of di-
meric [tpy–Ar60°–tpy–Ru2+–tpy–Ar60°–tpy] species with Zn2+
ions and a new, sulfur-modified tetrakis-terpyridinyl ligand. A
dynamic outcome is observed between the target bowtie-
shaped bis-macrocycle and a tetrakis-macrocyclic complex, if
the dimeric units are substituted with short OMe or OCH2C6H5
moieties. However, the use of long, hydrophobic, C16 alkyl
chains on the outer rim of the dimeric monomer forces the
reaction towards quantitative bowtie assembly. This phenome-
non is in agreement with a previous study,[7a] in which a core
tetrakis-terpyridine possessed short C6 alkyl substituents as sol-
ubilizing groups.
A primary goal related to single-step molecular-construction
procedures is the quantitative assembly of the desired target.
Of course, this has important ramifications in product isolation,
purification, and characterization, among other aspects. There-
fore, it is advantageous to limit the degrees-of-freedom related
to the possible outcomes of the transformation.
This is the goal for terpyridine-based, homoleptic, metal-me-
diated self-assembly, which is used widely for the construction
of supramolecular architectures,[1] such as macrocycles,[2]
cages,[3] and polyhedrons.[4] Beyond the simple shape consider-
ations provided by homoleptic complexes, heteroleptic assem-
blies[5] add to the available molecular design parameters by
allowing the incorporation of complementary substituents.
Thus, the molecular complexity and practical prospects can be
enhanced greatly by this “designer asymmetry.” The added flex-
ibility of heteroleptic assemblies broadens the construction out-
comes significantly and warrants renewed consideration.
The synthesis of ligand 2 was accomplished through multi-
ple Suzuki couplings with 2,3,7,8-tetrabromothianthrene (ob-
tained from the bromination[9] of commercially available thi-
anthrene) and the key intermediate 4′-(2,2′:6′,2′′-terpyridinyl)-
phenylboronic acid.[10] The product was purified by flash chro-
matography (73 %) and characterized by 1H and 13C NMR spec-
troscopy. The single set of peaks assigned to the terpyridinyl
1
moieties (e.g., H NMR: δ = 8.74 ppm, s, tpyH3′,5′) suggests that
the four arms of the ligand are in identical chemical and mag-
netic environments, as expected (Figure 1, c). This tetradentate
ligand consists of two 60°-oriented binding sites that form the
core of the target triangular macrocycle through combination
with two capping dimers and four ZnII ions.[7b]
Results and Discussion
Previously, we reported the self-assembly of homoleptic[6] and
heteroleptic[7] stable mono- and poly-triangular macrocycles.
Furthermore, we have developed several tetrakis- and hexakis-
macrocycles[8] with tpy–Ru2+–tpy connectivity (tpy = 2,2′:6′,2′′-
terpyridine). Herein, we report the self-assembly of bis-triangu-
The mono-Ru2+ terpyridinyl dimers were synthesized[7a] from
the corresponding 1,2-bis(terpyridinylphenyl)benzene (pre-
pared by a two-fold Suzuki coupling of an aryl dibromide and
the terpyridineboronic acid). The 1H NMR spectra of the dimeric
complexes showed two sets of terpyridinyl peaks [δ =
[a] Department of Polymer Science, The University of Akron,
170 University Cr., Akron, OH 44325-4717, USA
[b] Department of Chemistry, The University of Akron,
190 Buchtel Commons, Akron, OH 44325-3601, USA
E-mail: wesdemiotis@uakron.edu
newkome@uakron.edu
http://www.dendrimers.com
[‡] Jing-Yi Li and Ting-Zheng Xie contributed equally to this work.
Supporting information for this article is available on the WWW under
http://dx.doi.org/10.1002/ejic.201600048.
9.01 ppm, s, (complexed)tpy-H3′,5′; δ = 8.64 ppm, (free)tpy-H3′,5′
;
Figure 1], assigned to the different terpyridinyl moieties.
Notably, the shorter methoxy and benzyloxy substituents of 1b
1
and 1c exhibit two H NMR resonances that correspond to the
complexed and uncomplexed environments (Figures S6 and
S8); however, the dimer with the hexadecyloxy chains (1a)
shows a single resonance for the corresponding OCH2 moieties.
Eur. J. Inorg. Chem. 2016, 1671–1677
1671
© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Full Paper
Figure 1. 1H NMR spectra of (a) dimer 1a with hexadecyloxy groups, (b) bow-
tie-shaped complex 3a, and (c) tetrakis-terpyridinyl ligand 2.
The self-assembly of the bis-triangular macrocycles was
achieved by combining the tetrakis-terpyridinyl ligands, Ru2+
dimers, and zinc nitrate in a 1:2:4 ratio in a mixture of CHCl3
and MeOH (1:1 v/v). The addition of saturated aqueous NH4PF6
–
–
solution (to exchange the NO3 ions for PF6 ions) produced a
deep red precipitate, which was collected by filtration to give
hexadecyloxy (3a, 98 %), benzyloxy (3b, 80 %), and methoxy
(3c, 50 %) bowtie complexes (Scheme 1). Characterization was
accomplished through 1D and 2D NMR spectroscopy as well as
ESI-MS coupled with travelling wave ion mobility spectrometry
(ESI-TWIM-MS), a variant of ion mobility spectrometry[14]
whereby the ions are separated on the basis of their unique
charge and shape. The hydrophobic effect of the hexadecyloxy
chains in polar solvents forced the self-assembly toward the
formation of aggregates with less particles and greater charges.
By utilizing the hydrophobic effect, chemists have developed
tailored vesicles[11] and membranes,[12] but it is rare to construct
Scheme 1. Synthesis of the alkylated bowtie complexes 3a–3c. Dimer 1a with
the long C16H33 chain produced the desired product 3a quantitatively,
whereas shorter substituents resulted in mixtures.
plicated pattern of resonances, which were assigned to bis-tri-
single molecules.[13]
angle 3c (δ = 9.00, 8.98, 8.97 ppm, tpyH3′,5′; δ = 7.26, 7.25 ppm,
The H NMR spectrum of 3a shows a peak pattern that sug- PhHc) and tetramer 4c (δ = 9.00, 8.97 ppm, tpyH3′,5; δ = 7.21,
gests the formation of a discrete, symmetrical product (Fig- 7.20 ppm, PhHc). Two-dimensional COSY and NOESY NMR spec-
ure 1). The D2h symmetry of this bis-macrocyclic complex arises tra were used to confirm all assignments and verify the result-
from the arrangement of the two simple triangles and gives ing bowtie–tetramer mixture.
rise to three peak patterns corresponding to the three different
1
coordinated terpyridine moieties. All of the peaks were as-
1
signed on the basis of H–1H COSY and NOESY NMR spectra.
As expected, the two sets of terpyridine peaks for the dimeric
portion show downfield shifts (e.g., Figure 1, pink lines, δ = 8.64
to 8.97 ppm, tpyH3′,5′) as do the resonances of the tetra-armed
ligand (e.g., Figure 1, blue lines, δ = 8.74 to 8.96 ppm, tpyH3′,5′
)
owing to the coordination effect. Also noticeable are the single
downfield resonances attributed to the protons of the aryl thi-
anthrene rings (ArHc) and the protons of the dimeric unit
(ArHa,b; Δδ = 0.24 and 0.20 ppm downfield). The alkyloxy chains
for 3a, like those of 1a, display only one resonance for the OCH2
moieties.
Figure 2. Partial 1H NMR spectra of (a) 3a with hexadecyloxy chains, (b) 3b
with benzyloxy groups, and (c) 3c and 4c with methoxy groups. The triangles
indicate the resonances of the bowtie, and the squares indicate those of
the tetramer. The different colors indicate the corresponding moieties in the
structure.
1
The H NMR spectra for 3a and 3b appear similar and have
three separate tpy-H3′,5′ singlets (3a: δ = 8.99, 8.97, 8.97 ppm;
3b: δ = 8.99, 8.98, 8.96 ppm). Two singlets are assigned to the
outer vertex ArH protons of 3a (δ = 7.25, 7.23 ppm), whereas
The ESI-MS spectrum of the bis-triangle 3a with 12 PF6– ions
similar proton resonances for 3b appear further downfield. further supports the structure, and dominant peaks at m/z =
Analogously, the 1H NMR of 3c (Figure 2, c) shows a more com- 550.3, 613.6, 689.2, 781.9, 897.7, 1046.9, and 1245.3 correspond
Eur. J. Inorg. Chem. 2016, 1671–1677
www.eurjic.org
1672
© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Full Paper
to the charge states from 12+ to 6+, respectively. These m/z the bowtie complex 3a possesses the highest stability of the
values from the experimental mass spectrum are consistent three complexes (Figure S23). The gMS2 disappearance energies
with the calculated values. In contrast, the ESI-MS spectra of reflect the intrinsic stabilities of the complexes, which may be
the corresponding self-assembled benzyloxy- or methoxy-sub- affected by solvation. However, as all of the bowtie structures
stituted 3b and 3c, respectively, exhibit more complicated mass carry the same number of metal ions and counteranions, a po-
spectra comprising two sets of peaks: one set for the formation lar solvent (which will interact most strongly with these ionic
of the bis-macrocycles and another set indicating the presence sites) is not expected to change the intrinsic stability order.
of the substituted tetramers formed through the self-coupling
of the Ru2+ dimers with the Zn2+ ions. Evidence for the resulting
mixtures is discernible in both the NMR and MS data.
The computer-generated, energy-minimized modeling of 3a
reveals the rigid, shape-persistent, and highly symmetric bow-
tie-shaped structure with D2h symmetry. The longest distance
Additional supportive evidence for the structure of 3a was between two carbon atoms located at the vertices near the
provided by ESI-TWIM-MS experiments. The TWIM-MS spectrum alkyl chains is ca. 9.3 nm, and the distance between two Ru
of 3a (Figure 3) exhibits a single band of signals, indicative of ions in two outer rims of the triangles is ca. 4.7 nm. The same-
a single species with charge states of 11+ to 5+; this is consist- side corner-to-corner distances are ca. 6.1 nm.
ent with the NMR spectroscopy results. In contrast, the 2D
TWIM-MS spectra of 3b and 3c (Figure 3) both show two sets
of peaks, which are attributed to the bowtie and tetramer with
different sizes and shapes.
Further proof of the structures was provided by the collision
cross-sections (CCSs) determined from the drift times measured
in the TWIM-MS experiments. The CCSs for selected nanobowtie
ion charge states are shown in Table 1. The average values ob-
served for the charges from 9+ to 6+ (3a: 1183.7 Å2 3b:
1099.9 Å2 to 3c: 938.2 Å2) indicate a degree of flexibility for the
bowtie-shaped species with the disulfur moieties. Expectedly,
the largest CCS corresponds to the structure with the largest
corner substituents (i.e., OC16H33 for 3a).
Table 1. Experimentally determined CCS [Å2] versus charge for the substituted
bowties 3a–3c.
Charged species (z)
3a
3b
3c
9+
8+
7+
6+
1123.2
1173.4
1200.6
1237.7
1183.7
1041.5
1083.5
1135.0
1139.8
1099.9
873.4
925.7
961.6
991.9
938.2
Average
The UV/Vis absorption spectra for the tetradentate ligand 2
exhibited intense ligand-centered (LC) π–π* transitions from
the terpyridine moieties at λ = 292 nm (Figure 4). For the dimer
with hexadecyloxy chains, the bands at λ = 286 and 312 nm
could be assigned to the π–π* transitions of the terpyridinyl
units, and the peak at λ = 494 nm corresponds to a metal-to-
ligand charge transfer (MLCT). Upon the formation of 3a, the
coordination with ZnII ions increased the intensity of the band
Figure 3. The ESI-MS and TWIM-MS spectra of the bowtie reactions for 3a–
3c; the blue and red peaks and boxes correspond to the desired and unantici-
pated products, respectively.
Self-assembly with Zn2+ ions proceeds through reversible
equilibria that lead to the thermodynamically most stable prod-
uct(s). Our results indicate that long hydrophobic chains desta-
bilize the tetramer, in which such chains are closer to each
other than in the bowtie, and thereby shift the equilibrium 3
# 4 + 2 quantitatively to the side of the bowtie (3).
The stabilities of the bowtie complexes were probed sepa-
rately through gradient tandem MS (gMS2).[15] For each com-
plex, the 6+ charge ions [corresponding to m/z = 1245.33 (3a),
1066.38 (3b), and 964.85 (3c)] were isolated and subjected to
collisionally activated dissociation (CAD) before ion mobility
separation at nominal collision energies ranging from 10 to
70 eV. Notably, 3a with hexadecyloxy chains is more stable than
the related methoxy and benzyloxy derivatives. For 3b and 3c,
the 6+ ions were completely absent when the collision energy
reached 48 and 44 eV, respectively. However, for 3a, an in-
creased collision energy of 63 eV was required for the complete
disappearance of the 6+ ion (m/z = 1245.33). This indicates that
Figure 4. Comparison of the UV/Vis absorption spectra of dimer 1a, ligand 2,
and complex 3a.
Eur. J. Inorg. Chem. 2016, 1671–1677
www.eurjic.org
1673
© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Full Paper
NMR (500 MHz, CDCl3, 300 K): δ = 156.49, 156.02, 149.96, 149.24,
148.87, 142.48, 136.91, 136.38, 132.74, 130.63, 127.13, 123.84,
121.45, 118.92, 116.36, 69.74, 32.09, 29.89, 29.88, 29.84, 29.83, 29.63,
29.53, 26.25, 22.85, 14.28 ppm. MALDI-TOF MS: m/z = 1107.41
[C80H30N6O2 + H]+ (calcd. 1107.24)
at λ = 312 nm band, whereas the MLCT peak at λ = 496 nm
exhibited a redshift compared with that of the uncomplexed
RuII dimer.
Conclusions
[Ru(S3a)2Cl2] (1a): To a 1 L round-bottomed flask was added S3a
(1.17 mg, 1.0 mmol), RuCl2(DMSO)4 (162 mg, 333 μmol; DMSO =
dimethyl sulfoxide), and CHCl3/MeOH (700 mL, 1:1), and then the
mixture was heated under reflux for 48 h. The reaction mixture was
cooled to 25 °C and concentrated in vacuo to give a red powder,
which was purified by column chromatography (Al2O3) with a solu-
tion of CHCl3/MeOH (40:1) as the eluent to give uncomplexed S3a
initially and then 1a as a red powder (435 mg, 35 %); m.p. >300 °C.
1H NMR (500 MHz, CDCl3, 300 K): δ = 9.01 (s, 4 H, tpyHcomplex 3′,5′),
8.69 (d, J3,3′′-4,4′′ = 6.5 Hz, 4 H, tpyHcomplex 3,3′′), 8.64–8.63 (m,
A series of bowtie-shaped, supramolecules was prepared
through the heteroleptic self-assembly of Ru2+-coordinated ter-
pyridinyl dimers and a new tetrakis-terpyridinyl ligand. Un-
equivocal characterization was accomplished by 1D and 2D
NMR spectroscopy experiments, ESI-MS, gMS2, and ESI-TWIM-
MS analyses. The variation of the substituent groups revealed
that precise control of the self-assembly processes can be
achieved by enhancing the solubility of the ultimate product(s).
In turn, this provides insight into the future use of tailored self-
assembly protocols for the formation of supramacromolecules
as reagents for new and more readily accessed macromolecular
and nanoscale materials.
J3,3′′-4,4′′ = 4 Hz, J6,6′′-5,5′′ = 1 Hz, 12 H, tpyHfree 3′,5′, tpyHfree 3,3′′
tpyHfree 6,6′′), 8.02–7.97 (m, J3,3′′-4,4′′ = 6.5 Hz, J4,4′′-5,5′′ = 5.0 Hz,
Ja-b = 4.5 Hz, 8 H, PhHcomplex a, tpyHcomplex 4,4′′), 7.88 (dd, J3,3′′-4,4′′
5.0 Hz, J4,4′′-5,5′′ = 4.0 Hz, 4 H, tpyHfree 4,4′′), 7.81 (d, Ja-b = 3.5 Hz, 4
H, PhHfree a), 7.47–7.36 (m, J4,4′′-5,5′′ = 5.0 Hz, 8 H, tpyHcomplex 6,6′′
tpyHcomplex 5,5′′), 7.34 (d, Ja-b = 4.5 Hz, 4 H, PhHcomplex b), 7.30 (d,
Ja-b = 3.5 Hz, 4 H, PhHfree b), 7.16 (dd, J4,4′′-5,5′′ = 5.0 Hz, J5,5′′-6,6′′
8.0 Hz, 4 H, tpyHfree 5,5′′), 7.05 (s, 2 H, PhHcomplex c), 7.02 (s, 2 H,
PhHfree c), 4.13 (t, 8 H, JC1-C2 = 12 Hz, 2 × CH2), 1.84 (tt, 8 H, JC2-C1
,
=
,
=
Experimental Section
=
4,5-Dibromobenzene-1,2-diol (S1): Prepared by a literature proce-
12 Hz, JC2-C3 = 2 Hz, 2 × CH2), 1.52 (tt, JC3-C2 = 2 Hz, JC3-C4 = 0.6 Hz,
4 H, 2 × CH2), 1.33 (tt, JC4-C3 = 0.6 Hz, JC4-C5 = 1 Hz, 4 H, 2 × CH2),
1.19 (m, 22 H, 11 × CH2), 0.79 (t, 6 H, J = 2 Hz, 2 × CH3) ppm. 13C
NMR (500 MHz, CDCl3, 300 K): δ = 158.31, 155.22, 151.89, 151.43,
149.27, 144.95, 138.56, 134.08, 132.59, 132.39, 131.60, 131.07,
128.07, 127.53, 123.54, 122.25, 119.16, 116.35, 115.89, 112.35, 32.09,
dure.[7e]
1,2-Dibromo-4,5-bis(hexadecyloxy)benzene (S2a): A mixture of
4,5-dibromobenzene-1,2-diol (S1, 2.60 g, 8.0 mmol), 1-bromohexa-
decane (14.8 g, 25 mmol), toluene (100 mL), NaOH (2.0 g, 50 mmol)
in water (50 mL) and nBu4NBr (5 mmol) was heated under reflux
for 6 h. The mixture was then cooled to 25 °C, and the organic
phase was collected and concentrated in vacuo to afford S2a as a
white solid (6.8 g, 53 %); m.p. 92 °C. 1H NMR (500 MHz, CDCl3,
300 K): δ = 7.03 (s, 2 H, PhH), 4.11 (dd, 4 H, JC1-C2 = 12 Hz, 2 × CH2),
1.88 (dd, 4 H, JC1-C2 = 12 Hz, JC2-C3 = 2 Hz, 2 × CH2), 1.52 (dd,
JC2-C3 = 2 Hz, JC3-C4 = 2 Hz, 4 H, 2 × CH2), 1.35–1.25 (m, 22 H, 11 ×
CH2), 0.86 (t, 6 H, J = 2 Hz, 2 × CH3) ppm. 13C NMR (500 MHz, CDCl3,
300 K): δ = 149.20, 118.19, 114.81, 69.78, 32.09, 29.87, 29.85, 29.83,
29.77, 29.75, 29.70, 29.60, 29.53, 29.50, 29.21, 26.08, 22.85, 14.28
ppm. MALDI-TOF MS: m/z = 715.52 [C38H68Br2O2 + H]+ (calcd.
715.36).
29.90, 29.66, 26.32, 22.85, 14.27 ppm. ESI-MS: m/z = 2376.5 [M –
– +
NO3
] (calcd. 2376.4).
1,2-Bis(benzyloxy)-4,5-bis[p-(4′-terpyridinyl)phenyl]benzene
(S3b): To a three-necked 1 L round-bottomed flask, 1,2-bis(benzyl-
oxy)-4,5-dibromobenzene (1.50 g, 3.35 mmol), 4′-(4-boronatophen-
yl)- 2,2′:6′,2′′-terpyridine[10] (3.55 g, 10.1 mmol), Na2CO3 (7.10 g,
67.0 mmol), and a mixture of water (120 mL), toluene (200 mL), and
EtOH (180 mL) were added. The system was subjected to freeze–
pump–thaw cycles (3 ×) and back-filled with N2; then, PdCl2(PPh3)2
(280 mg, 400 μmol) was added. The resultant suspension was
heated under reflux for 48 h under N2. The mixture was cooled to
25 °C, and the aqueous layer was extracted with CHCl3 (3 × 50 mL).
The combined organic phase was dried (MgSO4) and concentrated
in vacuo to give a residue, which was purified by flash column
chromatography (Al2O3) with CHCl3 as the eluent to give S3b as a
white solid (1.95 g, 64 %); m.p. 219–221 °C. 1H NMR (500 MHz,
CDCl3, 300 K): δ = 8.74 (s, 2 H, tpyH3′,5′), 8.69 (d, J3,3′′-4,4′′ = 8 Hz, 2
H, tpyH3,3′′), 8.65 (d, J6,6′′-5,5′′ = 6 Hz, 2 H, tpyH6,6′′), 7.86 (dd,
J4,4′′-3,3′′ = J5,5′′-4,4′′ = 8 Hz, 2 H, tpyH4,4′′), 7.81 (d, Ja-b = 7.5 Hz, 2 H,
PhHa), 7.53 (d, Je-f = 7.5 Hz, 2 H, PhHe), 7.42 (dd, Jf-e = Jf-g = 7.5 Hz,
2 H, PhHf), 7.36 (t, Jg-f = 7.5 Hz, 1 H, PhHg), 7.30 (dd, J5,5′′-6,6′′ = 8 Hz,
4′,4′′′′-[4′,5′-Bis(hexadecyloxy)(1,1′:2′,1′′-terphenyl)-4,4′′-diyl]di-
2,2′:6′,2′′-terpyridine (S3a): Compound S2a (1.08 g, 15.0 mmol),
4′-boronatophenyl-2,2′:6′,2′′-terpyridine[10] (1.59 g, 45 mmol),
Na2CO3 (9.54 g, 90 mmol), and a solvent mixture of toluene
(300 mL), H2O (180 mL), and EtOH (120 mL) was added to a 1 L
flask. The system was subjected to freeze–pump–thaw cycles (3 ×)
and back-filled with nitrogen; then, PdCl2(PPh3)2 (61.76 mg,
1.2 mmol) was added. The resultant suspension was heated under
reflux for 48 h under nitrogen and then cooled to 25 °C, and the
aqueous layer was extracted with CHCl3 (3 × 50 mL). The combined
organic phase was dried (MgSO4) and concentrated in vacuo to give
a residue, which was recrystallized with hexane and CHCl3 and dried
with suction filtration to give S3a as a lavender solid (1.09 g, 62 %);
m.p. 47–48 °C. 1H NMR (500 MHz, CDCl3, 300 K): δ = 8.74 (s, 2 H,
J
5,5′′-4,4′′ = 5 Hz, 2 H, tpyH5,5′′), 7.26 (d, Jb-a = 7.5 Hz, 2 H, PhHb), 7.11
(s, 1 H, PhHc), 5.28 (s, 1 H, PhHd) ppm. 13C NMR (125 MHz, CDCl3,
300 K): δ = 156.46, 156.00, 150.01, 149.21, 148.72, 142.29, 137.44,
137.11, 136.52, 133.43, 130.65, 128.79, 128.14, 127.70, 127.23,
123.94, 121.59, 119.06, 117.72, 71.82 ppm. MALDI-TOF MS: m/z =
905.38 [C62H44N6O2+H]+ (calcd. 905.36).
tpyH3′,5′), 8.68 (d, J3,3′′-4,4′′ = 4 Hz, 2 H, tpyH3,3′′), 8.64 (d, J6,6′′-5,5′′
=
6.5 Hz, 2 H, tpyH6,6′′), 7.85 (dd, J4,4′′-3,3′′ = 4 Hz, J4,4′′-5,5′′ = 2.5 Hz, 2
H, tpyH4,4′′), 7.81 (d, Ja-b = 2.5 Hz, 2 H, PhHa), 7.32 (m, Jb-a = 2 Hz,
J
5,5′′-4,4′′ = 2.5 Hz, J5,5′′-6,6′′ = 6.5 Hz, 4 H, tpyH5,5′′, PhHb), 7.03 (s, 1 H, [Ru(S3b)2Cl2] (1b): To a 1 L round-bottomed flask were added S3b
PhHc), 4.11 (t, 4 H, JC1-C2 = 12 Hz, 2 × CH2), 1.88 (tt, 4 H, JC2-C1
12 Hz, JC2-C3 = 2 Hz, 2 × CH2), 1.52 (tt, JC3-C2 = 2 Hz, JC3-C4 = 0.6 Hz,
=
(905 mg, 1.0 mmol), RuCl2(DMSO)4 (162 mg, 333 μmol), and a sol-
vent mixture of CHCl3/MeOH (1:1, 700 mL), and the mixture was
4 H, 2 × CH2), 1.39 (tt, JC4-C3 = JC4-C5 = 0.6 Hz, 4 H, 2 × CH2), 1.35– heated under reflux for 48 h. The reaction was concentrated in
1.25 (m, 22 H, 11 × CH2), 0.86 (t, 6 H, J = 2 Hz, 2 × CH3) ppm. 13C
vacuo to give a red powder, which was purified by column chroma-
Eur. J. Inorg. Chem. 2016, 1671–1677
www.eurjic.org
1674
© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Full Paper
tography (Al2O3) with a mixture of CHCl3/MeOH (35:1) as the eluent
to give a red suspension, which was stirred and then heated under
reflux for 24 h. The mixture was extracted with a dilute solution of
sodium thiosulfate to remove any excess bromine. The crude prod-
uct was washed with water and dried in vacuo to give a faint yellow
to afford 1b as a red powder (325 mg, 34 %) after the removal of
1
uncomplexed S3b; m.p. >300 °C. H NMR (500 MHz, CD3OD/CDCl3
1:1, 300 K): δ = 9.34 (s, 4 H, tpyHcomplex 3′,5′), 9.11 (d, J3,3′′-4,4′′
=
6.0 Hz, 4 H, tpyHcomplex 3,3′′), 8.73 (s, 4 H, tpyHfree 3′,5′), 8.67–8.64 (m, solid, which was further rinsed with acetone and EtOH and dried
J3,3′′-4,4′′ = 4.0 Hz, J6,6′′-5′,5′′ = 7.5 Hz, 8 H, tpyHfree 3,3′′, tpyHfree 6,6′′),
to afford 1 as a white solid (7.42 g, 46 %); m.p. 252–268 °C (ref.[9]
247–264 °C). 1H NMR (500 MHz, CDCl3, 300 K): δ = 7.23 (s, 4 H, PhH)
ppm. 13C NMR (300 MHz, CDCl3, 300 K): δ = 138.91, 132.44, 125.27
ppm. MALDI-TOF MS: m/z = 528.46 [C12H4Br4S2+H]+ (calcd. 528.65).
8.32 (d, Ja - b = 4.5 Hz, 4 H, PhHc o m p l e x a ), 7.91–7.88 [m,
J3,3′′-4,4′′(complex) = 6.0 Hz, J4,4′′-5,5′′(complex) = 2.5 Hz, J3,3′′-4,4′′(free)
=
4.0 Hz, J4,4′′-5,5′′(free) = 3.5 Hz, 8 H, tpyHfree 4,4′′, tpyHcomplex 4,4′′], 7.80
(d, Ja-b = 2.5 Hz, PhHfree a), 7.55–7.46 [m, Jf-e(complex) = 0.6 Hz,
Jf-g(complex) = 1.0 Hz, Jf-e(free) = 0.4 Hz, Jf-g(free) = 0.8 Hz, 8 H,
PhHcomplex f, PhHfree f], 7.45 (d, Jb-a = 4.5 Hz, 4 H, PhHcomplex b), 7.42
2,3,7,8-Tetrakis[4-(2,2′:6′,2′′-terpyridin-4′-yl)phenyl]thianthrene
(2): Compound 1 (1.06 g, 2.00 mmol), 2[10] (4.24 g, 12.00 mmol),
Na2CO3 (5.30 g, 50 mmol), and a solvent mixture of toluene
(250 mL), H2O (150 mL), and EtOH (100 mL) were added to a 1 L
flask. The system was subjected to freeze–pump–thaw cycles (3 ×)
and back-filled with argon, and PdCl2(PPh3)2 (246 mg, 350 μmol)
was added. The resultant mixture was heated under reflux under
argon. The reaction mixture was cooled to 25 °C, and the aqueous
layer was extracted with CHCl3 (3 × 200 mL). The combined organic
phase was dried (MgSO4) and then concentrated in vacuo to give
a whitish yellow residue, which was purified by flash column chro-
matography (Al2O3) with a mixture of hexane, EtOAc, and CHCl3
(3:1:1 v/v/v) as the eluent to give 3 as an off-white solid (2.14 g,
[m, J5,5′′-4,4′′ = 2.5 Hz, J5,5′′-6,6′′ = 0.6 Hz, Jf-g(complex) = 1.0 Hz, Jf-g(free)
0.8 Hz, 8 H, tpyHcomplex 5,5′′, PhHcomplex g, PhHfree g], 7.36–7.34 [m,
Jb-a = 2.5 Hz, Jf-e(complex) = 0.6 Hz, Jf-e(free) = 0.4 Hz, 12 H, PhHfree b
PhHcomplex e, PhHfree e], 7.30 (d, J5,5′′-6,6′′ = 0.6 Hz, 4 H, tpyHcomplex 6,6′′),
7.22 (s, 2 H, PhHcomplex c), 7.18 (dd, J5,5′′-6,6′′ = 7.5 Hz, J5,5′′-4,4′′
=
,
=
3.5 Hz, 4 H, tpyHfree 5,5′′), 7.13 (s, 2 H, PhHfree c), 5.31 (s, 2 H,
PhHcomplex d), 5.29 (s, 2 H, PhHfree d) ppm. 13C NMR (125 MHz, CDCl3/
MeOD 2:1 v/v, 300 K): δ = 158.41, 155.67, 152.14, 150.67, 149.30,
149.05, 148.66, 144.41, 142.94, 138.94, 137.39, 137.31, 136.32,
134.48, 133.83, 133.22, 133.04, 131.69, 131.20, 128.95, 128.43,
127.99, 127.97, 127.81, 127.33, 125.50, 124.97, 122.72, 121.80,
120.58, 119.43, 117.99, 117.88, 72.26, 72.07 ppm. ESI-MS: m/z =
2055.57 [M – PF6]+ (calcd. 2055.57).
1
74 %); m.p. 225 °C. H NMR (500 MHz, CDCl3, 300 K): δ = 8.74 (s, 2
H, tpyH3′,5′), 8.69 (d, J3,3′′-4,4′′ = 4 Hz, 2 H, tpyH3,3′′), 8.65 (d, J6,6′′-5,5′′
=
6 Hz, 2 H, tpyH6,6′′), 7.87 (dd, J4,4′′-3,3′′ = J5,5′′-4,4′′ = 4 Hz, 2 H, tpyH4,4′′),
7.84 (d, Ja-b = 3 Hz, 2 H, PhHa), 7.71 (s, 1 H, PhHc), 7.34 (d, Jb-a
3,4-Bis(4-terpyridyl-p-phenyl)-o-dimethoxybenzene (S3c):[6b]
=
3 Hz, 2 H, PhHb), 7.32 (dd, J5,5′′-6,6′′ = 6 Hz, J5,5′′-4,4′′ = 4 Hz, 2 H,
tpyH5,5′′) ppm. 13C NMR (300 MHz, CDCl3, 300 K): δ = 156.27, 155.93,
149.78, 149.15, 139.98, 137.16, 137.10, 135.02, 130.90, 130.40,
127.38, 123.93, 121.51, 119.03 ppm. MALDI-TOF MS: m/z = 1446.74
[C96H60N12S2+H]+ (calcd. 1446.45).
1
M.p. 267.3–268.5 °C. H NMR (500 MHz, CDCl3, 300 K): δ = 8.75 (s,
2 H, tpyH3′,5′), 8.69 (d, J6,6′′-5,5′′ = 7 Hz, 2 H, tpyH6,6′′), 8.65 (d,
J
3,3′′-4,4′′ = 8 Hz, 2 H, tpyH3,3′′), 7.85 (m, 4 H, tpyH4,4′′, PhHa), 7.33 (m,
4 H, tpyH5,5′′, PhHb), 7.03 (s, 1 H, PhHc), 4.01 (s, 1 H, PhHd) ppm. 13C
NMR (300 MHz, CDCl3, 300 K): δ = 56.2, 113.6, 118.7, 123.7, 127.0,
130.5, 136.3, 142.2, 148.5, 149.1, 155.8, 156.2 ppm. ESI-MS: m/z =
753.3 [M + H]+ (calcd. 753.9).
[Ru2Zn4(2)(1a)4(PF6)12] (3a): To a solution of ligand 2 (2.17 mg,
15.0 μmol) and dimer 1a (7.56 mg, 30.0 μmol) in a solvent mixture
of CHCl3/MeOH (12 mL, 1:1), a solution of Zn(NO3)2·6H2O (1.79 mg,
60.0 μmol) in MeOH (6 mL) was added. The mixture was stirred for
1 h, and excess NH4PF6 was added to afford a dark red precipitate,
which was washed thoroughly with water and MeOH to give the
[Ru(S3c)2Cl2]: To a 1 L round-bottomed flask were added S3c
(750 mg, 1.0 mmol), RuCl2(DMSO)4 (162 mg, 333 μmol), and a sol-
vent mixture of CHCl3/MeOH (1:1, 700 mL), and then the mixture
was heated under reflux for 48 h. The reaction was concentrated in
vacuo to give a red powder, which was purified by column chroma-
tography (Al2O3) with CHCl3/MeOH (35:1) as the eluent to afford 1c
as a red powder (168 mg, 29 %) upon the removal of uncomplexed
S3c; m.p. >300 °C. 1H NMR (500 MHz, CD3OD/CDCl3 1:1, 300 K): δ =
9.36 (s, 4 H, tpyH complex 3′,5′), 9.14 (d, J3,3′′-4,4′′ = 6.5 Hz, 4 H,
tpyHcomplex 3,3′′), 8.71 (s, 4 H, tpyHfree 3′,5′), 8.62 (m, J3,3′′-4,4′′ = 4 Hz,
J6,6′′-5,5′′ = 1 Hz, 8 H, tpyHfree 3,3′′, tpyHfree 6,6′′), 8.32 (d, Ja-b = 5 Hz, 4
H, PhHcomplex a),7.84 [dd, J3,3′′-4,4′′(free) = 4 Hz, J4,4′′-5,5′′(free) = 3.5 Hz,
–
desired 3a with PF6 counterions as a dark red powder (11.75 mg,
1
95 %); m.p. >300 °C. H NMR (500 MHz, CD3CN, 300 K): δ = 8.99 (s,
8 H, tpyAH3′,5′), 8.97 (s, 8 H, tpyBH3′,5′), 8.97 (s, 8 H, tpyCH3′,5′), 8.70
[d, J3,3′′-4,4′′(B) = 6.5 Hz, 16 H, tpyBH3,3′′, J3,3′′-4,4′′(C) = 4.0 Hz, tpyCH3,3′′],
8.63 [d, J3,3′′-4,4′′(A) = 6.5 Hz, 8 H, tpyAH3,3′′], 8.17 [d, Ja-b(A) = 3.0 Hz,
8 H, PhAHa], 8.12 [d, Ja-b(B) = 2.5 Hz, Ja-b(C) = 2.5 Hz, 16 H, PhBHa,
PhCHa], 8.07 [d, 16 H, J3,3′′-4,4′′(B) = 6.5 Hz, J4,4′′-5,5′′(B) = 3.5 Hz,
J3,3′′-4,4′′(C) = 4.0 Hz, J4,4′′-5,5′′(C) = 2.5 Hz, tpyBH4,4′′, tpyCH4,4′′], 7.95 (s,
4 H, PhCHc), 7.84 [m, J3,3′′-4,4′′(A) = 6.5 Hz, J4,4′′-5,5′′(A) = 4.5 Hz,
J3,3′′-4,4′′(complex) = 5 Hz, J4,4′′-5,5′′(complex) = 3.5 Hz, 8 H, tpyHfree 4,4′′
,
J5,5′′-6,6′′(B) = 2.5 Hz, J5,5-6,6′′(C) = 1.0 Hz, 24 H, tpyAH4,4, tpyBH6,6′′
,
tpyHcomplex 4,4′′], 7.78 (d, Ja-b = 2.5 Hz, 4 H, PhHfree a), 7.48 (d,
tpyCH6,6′′], 7.61 [m, Ja-b(A) = 3.0 Hz, Ja-b(B) = 2.5 Hz, Ja-b(C) = 2.5 Hz,
24 H, PhAHb, PhBHb, PhCHb], 7.41 [d, J5,5-6,6′′(A) = 3.5 Hz, 8 H,
tpyAH6,6′′], 7.35 [dd, 16 H, J4,4′′-5,5′′(B) = 3.5 Hz, J5,5′′-6,6′′(B) = 2.5 Hz,
J4,4′′-5,5′′(C) = 2.5 Hz, J5,5-6,6′′(C) = 1.0 Hz, tpyBH5,5′′, tpyCH5,5′′], 7.25 (s,
4 H, PhAHc), 7.23 (s, 4 H, PhBHc), 7.14 [dd, J4,4′′-5,5′′(A) = 4.5 Hz,
J5,5-6,6′′(A) = 3.5 Hz, 8 H, tpyAH5,5′′], 4.21 (t, 16 H, JC1-C2 = 12 Hz, 8 ×
CH2), 1.88 (tt, 16 H, JC2-C1 = 12 Hz, JC2-C3 = 2 Hz, 8 × CH2), 1.58 (tt,
J6,6′′-5′,5′′ = 1 Hz, 4 H, tpyHcomplex 6,6′′), 7.33–7.29 [m, Jb-a(complex)
5 Hz, Jb-a(free) = 2.5 Hz, J5,5′′-4,4′′(complex) = 3.5 Hz, J5,5′′-6,6′′(complex)
=
=
1 Hz, 12 H, Ph-Hcomplex b, PhHfree b, tpyHcomplex 5,5′′], 7.12 [dd,
J5,5′′-4,4′′(free) = 3.5 Hz, J5,5′′-6,6′′(free) = 1 Hz, 4 H, tpyHfree 5,5′′], 7.07 (s,
1 H, PhHcomplex c), 6.98 (s, 1 H, PhHfree c), 3.98 (s, 1 H, PhHcomplex d),
3.95 (s, 1 H, PhHfree d) ppm. 13C NMR (300 MHz, CD3OD/CDCl3 1:1,
300 K): δ = 173.4, 157.8, 155.9, 155.0, 151.7, 149.5, 149.0, 148.7,
148.6, 148.5, 143.9, 142.3, 138.3, 137.1, 136.1, 166.9, 132.4, 131.9,
131.3, 130.6, 127.9, 127.5, 126.9, 125.1, 124.0, 121.4, 118.4, 116.6,
113.7, 56.2, 56.1 ppm. MALDI-MS: m/z = 1668.01 [M – NO3]+ (calcd.
1668.01).
J
C3-C2 = 2 Hz, JC3-C4 = 0.6 Hz, 16 H, 8 × CH2), 1.45 (tt, JC4-C3 = 0.6 Hz,
JC4-C5 = 1 Hz, 16 H, 8 × CH2), 1.42–1.29 (m, 176 H, 88 × CH2), 0.88
(t, 24 H, J = 2 Hz, 8 × CH3) ppm. 13C NMR (500 MHz, CD3CN, 300 K):
δ = 172.90, 171.07, 166.12, 159.17, 156.26, 150.84, 150.77, 148.95,
148.87, 148.82, 142.18, 142.16, 139.00, 138.13, 132.32, 132.12,
128.95, 128.65, 128.53, 128.50, 128.47, 124.25, 124.20, 122.43,
122.39, 32.64, 30.42, 30.37, 30.12, 30.07, 26.91, 23.38 ppm. ESI-MS:
2,3,7,8-Tetrabromothianthrene (S5): To thianthrene (6.48 g,
30 mmol) in a flask, bromine (38.4 g, 24 mmol) was added, and an
immediate reaction (take care) occurred with the evolution of HBr m/z = 1245.3 [M – 6PF6]6+ (calcd. 1244.1), 1046.9 [M – 7PF6]7+ (calcd.
gas. Then, glacial acetic acid (20 mL) was added to the black solid
1045.7), 897.7 [M – 8PF6]8+ (calcd. 896.9), 781.9 [M – 9PF6]9+ (calcd.
Eur. J. Inorg. Chem. 2016, 1671–1677
www.eurjic.org
1675
© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Full Paper
781.1), 689.2 [M – 10PF6]10+ (calcd. 688.5), 613.6 [M – 11PF6]11+ 7.80 [m, J3,3′′-4,4′′(A) = 4.0 Hz, J4,4′′-5,5′′(A) = 4.5 Hz, J5,5′′-6,6′′(B) = 1.0 Hz,
(calcd. 612.7), 550.3 [M – 12PF6]12+ (calcd. 549.6).
J5,5′′-6,6′′(C) = 1.0 Hz, Ja-b(C) = 4.0 Hz, 24 H, tpyAH4,4′′, tpyBH6,6′′
,
tpyCH6,6′′, PhCHb], 7.68–7.63 [m, Ja-b(B) = 2.5 Hz, Ja-b(A) = 3.0 Hz, 24
H, PhBHb, PhAHb], 7.41 [dd, J5,5′′-6,6′′(A) = 3.5 Hz, 8 H, tpyAH6,6′′], 7.37–
7.35 [m, J4,4′′-5,5′′(B) = 3.5 Hz, J5,5′′6,6′′(B) = 1.0 Hz, J4,4′′-5,5′′(C) = 2.5 Hz,
J5,5′′-6,6′′(C) = 1.0 Hz, 16 H, tpyBH5,5′′, tpyCH5,5′′], 7.21 (s, 4 H, PhAHc),
7.20 (s, 4 H, PhBHc), 7.15 [dd, J4,4′′-5,5′′(A) = 4.5 Hz, J5,5′′-6,6′′(A) = 3.5 Hz,
8 H, tpyAH5,5′′], 4.03 (s, 8 H, PhAHd), 4.01 (s, 8 H, PhBHd) ppm. 13C
NMR (500 MHz, CD3CN, 300 K): 159.18, 156.75, 156.59, 156.40,
153.35, 150.81, 150.77, 150.29, 148.93, 148.88, 148.68, 145.63,
145.46, 144.75, 144.51, 142.15, 138.95, 135.88, 135.73, 135.17,
134.98, 132.88, 132.32, 132.12, 128.68, 128.53, 128.46, 128.35,
125.53, 124.23, 122.42, 122.21, 122.09 ppm. ESI-MS: m/z = 1518.8
[M – 4PF6]4+ (calcd. 1518.2), 1086.8 [M – 5PF6]5+ (calcd. 1185.6),
964.9 [M – 6PF6]6+ (calcd. 963.8), 806.4 [M – 7PF6]7+ (calcd. 805.4),
687.4 [M – 8PF6]8+ (calcd. 686.6), 595.0 [M – 9PF6]9+ (calcd. 594.2),
521.0 [M – 10PF6]10+ (calcd. 520.3).
[Ru2Zn4(2)(1b)4(PF6)12] (3b): To a solution of ligand 2 (3.18 mg,
22.0 μmol) and dimer 1b (7.38 mg, 44.0 μmol) in a mixture of CHCl3/
MeOH (1:1, 12 mL), a solution of Zn(NO3)2·6H2O (2.46 mg,
88.0 μmol) in MeOH (6 mL) was added. The reaction mixture was
stirred for 1 h, and excess NH4PF6 was added to afford a dark red
precipitate, which was thoroughly washed with water and MeOH
–
(3 ×) to give the desired 3b as dark red powder with PF6 counter-
ions (8.26 mg, 76 %); m.p. >300 °C. 1H NMR (500 MHz, CD3CN,
300 K): δ = 8.99 (s, 8 H, tpyAH3′,5′), 8.98 (s, 8 H, tpyBH3′,5′), 8.96 (s, 8
H, tpyCH3′,5′), 8.71–8.70 [m, J3,3′′-4,4′′(B) = 6.5 Hz, J3,3′′-4,4′′(C) = 4.0 Hz,
16 H, tpyBH3,3′′, tpyCH3,3′′], 8.63 [d, J3,3′′-4,4′′(A) = 6.5 Hz, 8 H, tpyAH3,3′′],
8.18–8.07 [m, 40 H, Ja-b(A) = 3.0 Hz, J3,3′′-4,4′′(B) = 6.5 Hz, J4,4′′-5,5′′(B)
=
3.0 Hz, Ja-b(B) = 3.0 Hz, Ja-b(C) = 2.5 Hz, J3,3′′-4,4′′(C) = 4.0 Hz, J4,4′′-5,5′′(C)
= 3.5 Hz, PhAHa′′, tpyBH4,4′′, tpyCH4,4′′, PhBHa, PhCHa, tpyCH4,4′′], 7.95
(s, 4 H, PhCHc), 7.87–7.83 [m, J3,3′′-4,4′′(A) = 6.5 Hz, J4,4′′-5,5′′(A) = 4.0 Hz,
J5,5′′-6,6′′(B) = 1.5 Hz, J5,5′′-6,6′′(C) = 2.5 Hz, 24 H, tpyAH4,4′′, tpyBH6,6′′
,
=
[Ru2Zn2(1c)4(PF6)8] (4c): To a solution of 2 (2.89 mg, 20.0 μmol)
and dimer 1c (7.93 mg, 40.0 μmol) in a mixture of CHCl3/MeOH (1:1,
12 mL), a solution of Zn(NO3)2·6H2O (2.23 mg, 80.0 μmol) in MeOH
(6 mL) was added. The mixture was stirred for 1 h, and excess
NH4PF6 was added to afford a dark red precipitate, which was
washed thoroughly with water and MeOH to give the byproduct 4c
tpyCH6,6′′], 7.66 [d, Ja-b(C) = 2.5 Hz, 4 H, PhCHb], 7.59–7.57 [m, Ja-b(A)
3.0 Hz, Ja-b(B) = 3.0 Hz, J4,4′′-5,5′′(B) = 3.0 Hz, J5,5′′-6,6′′(B) = 1.5 Hz, 40 H,
PhAHc, PhBHc, PhAHb, PhBHb, tpyBH5,5′′],
7.48 [dd,
Je-f(A) = 0.6 Hz, Jf-g(A) = 0.3 Hz, Je-f(B) = 0.6 Hz, Jf-g(B) = 0.3 Hz, 16 H,
PhAHf, PhBHf], 7.43–7.41 [m, J5,5′′-6,6′′(A) = 1.5 Hz, Jf-g(A) = 0.3 Hz,
–
= ,
0.3 Hz, 24 H, tpyAH6,6′′ PhAHg, PhBHg], 7.41–7.35
with PF6 counterions as a dark red powder along with bowtie 3c.
Jf-g(B)
[m, J4,4′′-5,5′′(C) = 3.5 Hz, J5,5′′-6,6′′(C) = 2.5 Hz, Je-f(A) = 0.6 Hz, Je-f(B)
0.6 Hz, 24 H, tpyCH5,5′′, PhAHe, PhBHe], 7.13 [dd, J4,4′′-5,5′′(A) = 4.0 Hz,
5,5′′-6,6′′(A) = 1.5 Hz, 8 H, tpyAH5,5′′], 5.36 (s, 8 H, PhAHd, PhBHd) ppm.
1
The H NMR and ESI-MS spectra are shown in parts c of Figures 2
=
and 3, respectively, and confirm the presence of byproduct 4c along
with the known bowtie 3c in an approximate ratio of 2:3. ESI-MS:
m/z = 1356.4 [M – 3PF6]3+ (calcd. 1355.2), 981.0 [M – 4PF6]4+ (calcd.
980.2), 755.6 [M – 5PF6]5+ (calcd. 755.1), 605.7 [M – 6PF6]6+ (calcd.
605.1).
J
13C NMR (500 MHz, CD3CN, 300 K): δ = 159.12, 156.57, 156.39,
153.32, 150.79, 150.24, 149.71, 148.92, 148.83, 148.80, 142.14,
138.94, 132.33, 132.21, 132.09, 129.61, 129.14, 128.87, 128.44,
125.33, 124.18, 122.39, 118.26, 72.15, 56.89, 30.40, 14.05 ppm. ESI-
MS: m/z = 1308.6 [M – 5PF6]5+ (calcd. 1307.2), 1066.4 [M – 6PF6]6+
Supporting Information (see footnote on the first page of this
article): Experimental procedures and characterization data contain-
ing COSY and NOESY NMR, ESI-MS, tandem mass, and UV/Vis ab-
sorption spectra.
(calcd. 1065.2), 893.2 [M – 7PF6 ]
– 7+ (calcd. 892.3), 763.4 [M – 8PF6]8+
(calcd. 762.7), 662.5 [M – 9PF6]9+ (calcd. 661.8), 581.9 [M – 10PF6]10+
(calcd. 581.1), 515.8 [M – 11PF6]11+ (calcd. 515.1).
[Ru2Zn2(1b)4(PF6)8] (4b): To a solution of ligand 2 (3.18 mg,
22.0 μmol) and dimer 1b (7.38 mg, 44.0 μmol) in a solvent mixture
of CHCl3/MeOH (1:1, 12 mL), a solution of Zn(NO3)2·6H2O (2.46 mg,
Acknowledgments
The authors gratefully acknowledge funding from the US Na-
88.0 μmol) in MeOH (6 mL) was added. The reaction mixture was tional Science Foundation (NSF) (grant numbers CHE-1151991
stirred for 1 h, and excess NH4PF6 was added to afford a dark red
precipitate, which was washed thoroughly with water and MeOH
(3 ×) to give the desired 4b as dark red powder with PF6 counter-
GRN and CHE-1308307 CW).
–
Keywords: Supramolecular chemistry · Self-assembly ·
Hydrophobic effect · Nitrogen heterocycles
ions along with bowtie 3b. The 1H NMR and ESI-MS spectra are
shown in parts b of Figures 2 and 3, respectively, and confirm the
presence of byproduct 4b with the known bowtie 3b in an approxi-
mate ratio of 1:4: ESI-MS: m/z = 1133.1 [M – 4PF6]4+ (calcd. 1132.2),
877.5 [M – 5PF6]5+ (calcd. 876.8), 707.1 [M – 6PF6]6+ (calcd. 706.5),
585.6 [M – 7PF6]7+ (calcd. 584.9), 494.1 [M – 8PF6]8+ (calcd. 493.6).
[1] a) J.-M. Lehn, Supramolecular Chemistry: Concepts and Perspectives, Wiley-
VCH, Weinheim, Germany, 1995; b) R. Chakrabarty, P. S. Mukherjee, P. J.
Stang, Chem. Rev. 2011, 111, 6810–6918; c) T. R. Cook, Y.-R. Zheng, P. J.
Stang, Chem. Rev. 2013, 113, 734–777; d) G. R. Newkome, C. N. Moore-
field, Chem. Soc. Rev. 2015, 44, 3954–3967; e) T. R. Cook, P. J. Stang,
Chem. Rev. 2015, 115, 7001–7045.
[2] a) G. R. Newkome, T. J. Cho, C. N. Moorefield, G. R. Baker, R. Cush, P. S.
Russo, Angew. Chem. Int. Ed. 1999, 38, 3717–3721; Angew. Chem. 1999,
111, 3899–3903; b) M. Fujita, J. Yazaki, K. Ogura, J. Am. Chem. Soc. 1990,
112, 5645–5647; c) B. Hasenknopf, J.-M. Lehn, B. O. Kneisel, G. Baum, D.
Fenske, Angew. Chem. Int. Ed. Engl. 1996, 35, 1838–1840; Angew. Chem.
1996, 108, 1987–1990; d) G.-H. Ning, T.-Z. Xie, Y.-J. Pan, Y.-Z. Li, S.-Y. Yu,
Dalton Trans. 2010, 39, 3203–3211; e) X. Yu, X. Li, Y. Cao, A. Schultz, J.-L.
Wang, C. N. Moorefield, C. Wesdemiotis, S. Z. D. Cheng, G. R. Newkome,
Angew. Chem. Int. Ed. 2013, 52, 7728–7731; Angew. Chem. 2013, 125,
7882–7885; f) Y. Li, Z. Jiang, J. Yuan, T. Wu, C. N. Moorefield, G. R. Newk-
ome, P. Wang, Chem. Commun. 2015, 51, 5766–5769.
[Ru2Zn4(2)(1c)4(PF6)12] (3c): To a solution of ligand 2 (2.89 mg,
20.0 μmol) and dimer 1c (7.93 mg, 40.0 μmol) in a mixture of CHCl3/
MeOH (1:1, 12 mL), a solution of Zn(NO3)2·6H2O (2.23 mg,
80.0 μmol) in MeOH (6 mL) was added. The mixture was stirred for
1 h, and excess NH4PF6 was added to afford a dark red precipitate,
which was washed thoroughly by water and then MeOH to give
the desired 3c with PF6– counterion as a dark red powder (5.16 mg,
1
48 %); m.p. >300 °C. H NMR (500 MHz, CD3CN, 300 K): δ = 9.00 (s,
8 H, tpyAH3′,5′), 8.98 (s, 8 H, tpyBH3′,5′), 8.97 (s, 8 H, tpyCH3′,5′), 8.71–
8.69 [m, J3,3′′-4,4′′(B) = 4.0 Hz, J3,3′′-4,4′′(C) = 4.0 Hz, 16 H, tpyBH3,3′′
,
tpyCH3,3′′], 8.63 [d, J3,3′′-4,4′′(A) = 4.0 Hz, 8 H, tpyAH3,3′′], 8.18–8.06 [m,
40 H, Ja-b(A) = 4.0 Hz, Ja-b(B) = 2.5 Hz, Ja-b(C) = 2.0 Hz, J3,3′′-4,4′′(B)
=
4.0 Hz, J4,4′′-5,5′′(B) = 3.5 Hz, J3,3′′-4,4′′(C) = 4.0 Hz, J4,4′′-5,5′′(C) = 2.5 Hz,
[3] a) M. Han, D. M. Engelhard, G. H. Clever, Chem. Soc. Rev. 2014, 43, 1848–
1860; b) S. R. Seide, P. J. Stang, Acc. Chem. Res. 2002, 35, 972–983; c) T.
PhAHa, PhBHa, PhCHa, tpyBH4,4′′, tpyCH4,4′′], 7.95 (s, 4 H, PhCHc), 7.88–
Eur. J. Inorg. Chem. 2016, 1671–1677
www.eurjic.org
1676
© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Full Paper
Schröder, R. Brodbeck, M. C. Letzel, A. Mix, B. Schnatwinkel, M. Tonigold,
D. Volkmer, J. Mattay, Tetrahedron Lett. 2008, 49, 5939–5942; d) T.-Z. Xie,
S.-Y. Liao, K. Guo, X. Lu, X. Dong, M. Huang, C. N. Moorefield, S. Z. D.
Cheng, X. Liu, C. Wesdemiotis, G. R. Newkome, J. Am. Chem. Soc. 2014,
136, 8165–8168; e) M. C. Young, L. R. Holloway, A. M. Johnson, R. J. Hoo-
ley, Angew. Chem. Int. Ed. 2014, 53, 9832–9836; Angew. Chem. 2014, 126,
9990–9994; f) S.-Y. Yu, Q. Jiao, S.-H. Li, H.-P. Huang, Y.-Z. Li, Y.-J. Pan, Y.
Sei, K. Yamaguchi, Org. Lett. 2007, 9, 1379–1382; g) S. Sato, J. Iida, K.
Suzuki, M. Kawano, T. Ozeki, M. Fujita, Science 2006, 313, 1273–1276.
[4] a) D. L. Caulder, C. Brückner, R. E. Powers, S. König, T. N. Parac, J. A. Leary,
K. N. Raymond, J. Am. Chem. Soc. 2001, 123, 8923–8938; b) P. Mal, B.
Breiner, K. Rissanen, J. R. Nitschke, Science 2009, 324, 1697–1699; c) T.-Z.
Xie, K. Guo, Z. Guo, L. Wojtas, G.-H. Ning, M. Huang, X. Lu, J.-Y. Li, S.-Y.
Liao, Y.-S. Chen, C. N. Moorefield, M. J. Saunders, S. Z. D. Cheng, C. Wesde-
miotis, G. R. Newkome, Angew. Chem. Int. Ed. 2015, 54, 9224–9229;
Angew. Chem. 2015, 127, 9356–9361; d) X. Lu, X. Li, K. Guo, T.-Z. Xie, C. N.
Moorefield, C. Wesdemiotis, G. R. Newkome, J. Am. Chem. Soc. 2014, 136,
18149–18155; e) X. Lu, X. Li, K. Guo, M. Huang, J.-L. Wang, T.-Z. Xie, C. N.
Moorefield, S. Z. D. Cheng, C. Wesdemiotis, G. R. Newkome, Chem. Eur. J.
2014, 20, 13094–13098.
[5] a) S. De, K. Mahata, M. Schmittel, Chem. Soc. Rev. 2010, 39, 1555–1575;
b) J. Fan, M. L. Saha, B. Song, H. Schönherr, M. Schmittel, J. Am. Chem.
Soc. 2012, 134, 150–153; c) N. Mittal, M. L. Saha, M. Schmittel, Chem.
Commun. 2015, 51, 15514–15517; d) M. L. Saha, S. Neogi, M. Schmittel,
Dalton Trans. 2014, 43, 3815–3834; e) M. Schmittel, Chem. Commun.
2015, 51, 14956–1968; f) A. J. Metherell, M. D. Ward, Chem. Sci. 2016, 7,
910–915.
[6] a) S.-H. Hwang, C. N. Moorefield, F. R. Fronczek, O. Lukoyanova, L. Eche-
goyen, G. R. Newkome, Chem. Commun. 2005, 713–715; b) A. Schultz, Y.
Cao, M. Huang, S. Z. D. Cheng, X. Li, C. N. Moorefield, C. Wesdemiotis,
G. R. Newkome, Dalton Trans. 2012, 41, 11573–11575.
Newkome, Angew. Chem. Int. Ed. 2014, 53, 12182–12185; Angew. Chem.
2014, 126, 12378–12381; d) X. Lu, X. Li, J.-L. Wang, C. N. Moorefield, C.
Wesdemiotis, G. R. Newkome, Chem. Commun. 2012, 48, 9873–9875; e)
S. De, S. Chaudhuri, S. Mishra, H. Mamtani, A. Bisai, J. Indian Chem. Soc.
2013, 90, 1871–1884.
[8] a) A. Schultz, P. Li, C. E. McCusker, C. N. Moorefield, F. N. Castellano, C.
Wesdemiotis, G. R. Newkome, Chem. Eur. J. 2012, 18, 11569–11572; b) A.
Schultz, X. Li, C. N. Moorefield, C. Wesdemiotis, G. R. Newkome, Eur. J.
Inorg. Chem. 2013, 2492–2497.
[9] H. Gilman, D. Swayampati, J. Org. Chem. 1958, 23, 313–314.
[10] P. Jarozs, K. Lotito, J. Schneider, D. Kumaresan, R. Schmehl, R. Eisenberg,
Inorg. Chem. 2009, 48, 2420–2428.
[11] a) Z. Ge, S. Liu, Chem. Soc. Rev. 2013, 42, 7289–7325; b) K. Higashiguchi,
G. Taira, J. Kitai, T. Hirose, K. Matsuda, J. Am. Chem. Soc. 2015, 137, 2722–
2729.
[12] P. van Rijn, M. Tutus, C. Kathrein, L. Zhu, M. Wessling, U. Schwaneberg,
A. Böker, Chem. Soc. Rev. 2013, 42, 6578–6592.
[13] A. Honciuc, D. K. Schwartz, J. Am. Chem. Soc. 2009, 131, 5973–5979.
[14] a) S. L. Bernstein, N. F. Dupuis, N. D. Lazo, T. Wyttenbach, M. M. Condron,
G. Bitan, D. B. Teplow, J.-E. Shea, B. T. Ruotolo, C. V. Robinson, M. T.
Bowers, Nat. Chem. 2009, 1, 326–331; b) B. T. Ruotolo, J. L. P. Benesch,
A. M. Sandercock, S.-J. Hyung, C. V. Robinson, Nat. Protoc. 2008, 3, 1139–
1152; c) C. A. Scarff, J. R. Snelling, M. M. Knust, C. L. Wilkins, J. H. Scrivens,
J. Am. Chem. Soc. 2012, 134, 9193–9198; d) K. Thalassinos, M. Graben-
auer, S. E. Slade, G. R. Hilton, M. T. Bowers, J. H. Scrivens, Anal. Chem.
2009, 81, 248–254; e) E. R. Brocker, S. E. Anderson, B. H. Northrop, P. J.
Stang, M. T. Bowers, J. Am. Chem. Soc. 2010, 132, 13486–13494; f) S. E.
Anderson, C. Bleiholder, E. R. Brocker, P. J. Stang, M. T. Bowers, Int. J. Mass
Spectrom. 2012, 330–332, 78–84; g) S. Trimpin, M. Plasencia, D. Isailovic,
D. E. Clemmer, Anal. Chem. 2007, 79, 7965–7974.
[15] X. Li, Y.-T. Chan, G. R. Newkome, C. Wesdemiotis, Anal. Chem. 2011, 83,
1284–1290.
[7] a) A. Schultz, X. Li, B. Barkakaty, C. N. Moorefield, C. Wesdemiotis, G. R.
Newkome, J. Am. Chem. Soc. 2012, 134, 7672–7675; b) T.-Z. Xie, K. Guo,
M. Huang, X. Lu, S.-Y. Liao, R. Sakar, C. N. Moorefield, S. Z. D. Cheng, C.
Wesdemiotis, G. R. Newkome, Chem. Eur. J. 2014, 20, 11291–11294; c) R.
Sarkar, K. Guo, C. N. Moorefield, M. J. Saunders, C. Wesdemiotis, G. R.
Received: January 19, 2016
Published Online: March 14, 2016
Eur. J. Inorg. Chem. 2016, 1671–1677
www.eurjic.org
1677
© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim