Synthesis, Structure, Property, and Dinuclear Cu(II) Complexation of Tetraoxacalix[2]arene[2]phenanthrolines

Article abstract of DOI:10.1021/acs.inorgchem.8b02039

A number of novel tetraoxacalix[2]arene[2]phenanthrolines 7-11 containing phenanthroline and diverse aromatic linkages were conveniently synthesized by a one-pot protocol between a series of dihydroxy arenes and 1,10-phenanthroline derivatives. Single-crystal diffraction analysis revealed that the resulting macrocycles possess diverse conformational and cavity structures which are regulated by the different aromatic linkages. In line with the length of the aromatic linkages, the distance between the two phenanthroline moieties (d_N-N) gradually increases from 6.92 to 13.30 ?, respectively. The physicochemical properties of these macrocyclic compounds were investigated by spectroscopic, CV, and DPV measurements. Owing to the coordination ability of the phenanthroline moieties and the tunable conformational structure, the macrocyclic hosts can form distinct dinuclear complexation with Cu²⁺. Typically, with a short aromatic linkage the 7b-2Cu(II) complex gives an O-bridged dicopper structure, while with long linkage the 11b-2Cu(II) complex possesses two discrete copper centers. The spectroscopic structure and the redox property of the dicopper complexes were investigated by XPS, CV, and DPV techniques. This work hence provides a platform to access biomimetic copper-containing small-molecule models with well-defined structures.

Full text of DOI:10.1021/acs.inorgchem.8b02039

Article
pubs.acs.org/IC
Cite This: Inorg. Chem. XXXX, XXX, XXX−XXX
Synthesis, Structure, Property, and Dinuclear Cu(II) Complexation of
Tetraoxacalix[2]arene[2]phenanthrolines
Xue-Yuan Wang,†,‡ Yu-Fei Ao,† Qi-Qiang Wang,*,†,‡ and De-Xian Wang*,†,‡
†CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Science, Beijing National
Laboratory for Molecular Sciences, Beijing 100191, China
‡University of Chinese Academy of Sciences, Beijing 100049, China
S
* Supporting Information
ABSTRACT: A number of novel tetraoxacalix[2]arene[2]phenanthrolines 7−11 containing phenanthroline and diverse
aromatic linkages were conveniently synthesized by a one-pot protocol between a series of dihydroxy arenes and 1,10-
phenanthroline derivatives. Single-crystal diffraction analysis revealed that the resulting macrocycles possess diverse
conformational and cavity structures which are regulated by the different aromatic linkages. In line with the length of the
aromatic linkages, the distance between the two phenanthroline moieties (dN−N) gradually increases from 6.92 to 13.30 Å,
respectively. The physicochemical properties of these macrocyclic compounds were investigated by spectroscopic, CV, and
DPV measurements. Owing to the coordination ability of the phenanthroline moieties and the tunable conformational structure,
the macrocyclic hosts can form distinct dinuclear complexation with Cu2+. Typically, with a short aromatic linkage the 7b−
2Cu(II) complex gives an O-bridged dicopper structure, while with long linkage the 11b−2Cu(II) complex possesses two
discrete copper centers. The spectroscopic structure and the redox property of the dicopper complexes were investigated by
XPS, CV, and DPV techniques. This work hence provides a platform to access biomimetic copper-containing small-molecule
models with well-defined structures.
recognition,19−21 self-assembly,22−28 and stimuli responsive
INTRODUCTION
■
materials.29 On the other hand, owing to the appealing
Macrocyclic molecules are of fundamental importance to
chemical and structural features such as the strong
supramolecular chemistry. The sophisticated design of
coordination ability and the outstanding photochemical and
ingenious macrocyclic molecules has ever been one of the
photophysical properties, 1,10-phenanthrolines have found
key driving forces to advance supramolecular chemistry and
extensive applications in organic synthesis, material science,
related fields. Importantly, macrocyclic molecules provide ideal
models not only to study the nature of noncovalent
biological systems, and supramolecular chemistry.30−36 To the
best of our knowledge, however, heteracalixaromatics that are
interactions but also to obtain a deep understanding of living
systems.1−3 Recent years have witnessed tremendous develop-
composed of the 1,10-phenanthroline unit remain unknown.
Copper-containing enzymes are important metalloproteins
ment of a new generation of macrocyclic host molecules
named heteracalixaromatics.4−10 Replacement of methylene
in life that bind, activate, and reduce O2 through the
biologically accessible CuII/CuI redox couple.37−41 The
groups with heteroatoms as the bridging moieties, and the
coordination environment of the Cu active center in these
incorporation of various (hetero)aromatics including triazine,
enzymes and proteins plays a crucial role in determining their
function. For example, whereas trigonal ligation of Cu(I) by
pyrimidine, pyrazine, pyridine, and naphthyridine have
endowed heteracalixaromatics unique structures and powerful
recognition properties.4,5,11−18 Oxacalixaromatics, for example,
are a typical member of the heteracalixaromatic family and
have been remarkably applied in the studies of molecular
Received: July 21, 2018
© XXXX American Chemical Society
A
DOI: 10.1021/acs.inorgchem.8b02039
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uncharged ligands is common for reduced hemocyanin
(redHc), a five-coordinated Cu(II) center with a distorted
square-pyramidal geometry exists in oxygenated hemocyanin
(oxyHc). Inspired by the structural feature and function of
copper-containing enzymes, biomimetic study using small-
molecule models has been one of the active and attractive
fields during the past years.42−46 As our interest in the
development of novel synthetic macrocyclic host molecules
continues, we envisioned if suitable Cu-ligands can be
organized into a macrocyclic skeleton, i.e. incorporating the
superior 1,10-phenanthroline moieties to form tetraoxacalixar-
omatics. In this way, well-defined macrocyclic dinuclear Cu
complexes can be accessed where the Cu−Cu distance and
binding environment can be finely tuned by choosing
appropriate nucleophilic aromatic components. Herein we
reported the synthesis, structure, spectroscopic properties, and
dinuclear Cu(II) complexation of a series of tetraoxacalix[2]-
arene[2]phenanthrolines.
1). The use of other inorganic bases such as K2CO3, CsF, and
K3PO4 can also afford the product but with diminished yields
(entries 2−4). The use of organic bases such as DIPEA and
DBU, however, did not give any macrocycle product (entries
5−6). With the best base Cs2CO3, different solvents were then
screened (entries 7−11). To our delight, DMF was found as a
superior solvent and the yield can be further increased to 73%
(entry 7). By a slow addition of the reactants and elongating
reaction time to 24 h, the yield was further increased to 79%
(entry 13). The result demonstrates that under the
combination of the very polar solvent DMF and Cs2CO3, the
one-pot macrocyclization can be very efficient.
Under the optimized combination of DMF and Cs2CO3, the
one-pot reaction procedure was then applied to the synthesis
of other tetraoxacalix[2]arene[2]phenanthroline analogues 7−
11 (Scheme 1). Different diphenols at varied spacing distances
Scheme 1. One-Pot Synthesis of
Tetraoxacalix[2]arene[2]phenanthrolines 7−11
RESULTS AND DISCUSSION
■
We have previously shown that one-pot reaction can work
efficiently for the construction of oxygen and nitrogen-bridged
calix[2]arene[2]triazines by using an appropriate base and
solvent.47 The synthesis of tetraoxacalix[2]arene[2]-
phenanthrolines was therefore investigated based on this
efficient protocol. The conditions for synthesizing
tetraoxacalix[2]arene[2]phenanthroline 7a from resorcinol 1a
and 2,9-dichloro-1,10-phenanthroline 6a were first optimized.
As listed in Table 1, by heating at 100 °C in DMSO in the
presence of Cs2CO3, the reaction proceeded smoothly to
afford the desired macrocycle product 7a in 54% yield (entry
Table 1. One-Pot Synthesis of
Tetraoxacalix[2]arene[2]phenanthroline 7a.
a
Entry
Base
Solvent
Time (h)
Yield (%)
1
2
3
4
5
6
7
8
Cs2CO3
K2CO3
CsF
K3PO4
DIPEA
DBU
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
DMSO
DMSO
DMSO
DMSO
DMSO
DMSO
DMF
CH3CN
pyridine
THF
12
12
12
12
12
12
12
12
12
12
12
54
9
25
5
b
b
73
15
54
14
36
71
79
including resorcinols (1), 2,7-naphthalenediol (2), 4,4′-oxybi-
sphenol (3), 4,4′-dihydroxybenzophenone (4), and m-
terphenyl-4,4″-diol (5) were applied. To improve the solubility
and also to probe the substituent effect, 3,5-dihydroxyben-
zoates (1b, 1c) and 5,6-dibutoxy substituted phenanthroline
(6b) were also used. Pleasantly, all the desired macrocycle
products can be readily obtained in acceptable yields of 13%−
79%. This one-pot procedure hence provided a reliable
synthetic routine to rapidly access the series of
tetraoxacalix[2]arene[2]phenanthrolines with structural diver-
sity.
All the macrocycle compounds were fully characterized
based on spectroscopic and elemental analysis data (see
Supporting Information). To elucidate their conformational
structure, single crystals of 7b, 7d, 8b, 9b, 10b, 11a, and 11b
were cultivated by a slow evaporation or diffusion method and
subjected to X-ray diffraction analysis (Tables S1−S4). As
9
10
11
12
13
acetone
DMF
DMF
c
3 + 12
6 + 24
c
a
The reactions were heated at 100 °C in a sealed tube. The
concentrations of 1a and 6a are 66 mM, respectively. No macrocycle
product detected. The mixed solution of 1a and 6a was added with
an injection pump during a period.
b
c
B
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Figure 1. Crystal structures of macrocycles (A) 7b, (B) 8b, (C) 9b, (D) 10b, and (E) 11b in top and side views. Alkyl chains of the butoxyl
substituents, hydrogen atoms, and solvent molecules are omitted for clarity. (F) The listed spacing distance for the corresponding diphenol linker.
illustrated in Figure 1, the incorporation of the different
diphenol linkers can finely regulate the conformational
structure of the macrocyclic skeleton. For example, the
distance of the coordination nitrogen atom sites between the
two phenanthrolines (dN−N) gradually increases from 7b to
11b in the value of 6.92 Å for 7b, 9.35 Å for 8b, 12.29 Å for 9b,
12.43 Å for 10b, and 13.30 Å for 11b, which is in line with the
spacing distance of the diphenol linkers extended from 5.08 to
12.62 Å. As anticipated in all cases the bridging oxygen atoms
tend to form conjugation with the phenanthroline rings due to
their more electron-deficiency than the phenol rings. The
macrocycles 7b and 8b adopt a similar flattened 1,3-alternate
conformation in which the two phenanthroline moieties are
flattened into the same plane while the diphenol rings are
tilted, forming a butterfly like structure (Figures 1A and 1B).
This is in contrast to the typical 1,3-alternate conformation of
the tetraoxacalixaromatics that are meta-linked across each
(het)arene.11,13,15 For 7d, with the bulky benzyloxycarbony
group on the diphenol ring, a distorted (but not flatten) 1,3-
alternate conformation was observed (Figure S1). In 9b and
10b, the two phenanthrolines are still flattened but the two
extended oxybiphenol and benzophenone moieties are now
oppositely arrayed, leading to a centrosymmetric chairlike
structure (Figures 1C and 1D). With the rigid and extended
terphenyl linkers, the macrocycle 11b adopts a U-shape
conformation in which the two phenanthrolines are
perpendicularly arrayed (Figure 1E). The perpheral butoxy
substituents on phenanthrolines hardly affect the macrocycle
conformation as exemplified by the very similar structure
observed for 11a (Figure S2). Different from the rich
conformational structures observed in solid states, all the
macrocycle compounds 7−11 show only one set of proton and
carbon signals in their NMR spectra at room temperature,
reflecting the conformational flexibility in solution (Figures
S32−S43).
To shed light on the physicochemical properties of 7−11,
their electronic spectroscopy and redox property were
investigated. The UV−vis spectra of all soluble compounds
in dichloromethane show two absorption bands in the range of
λmax = 340−380 nm with molar extinction coefficients (ε)
C
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Figure 2. (A) UV−vis and (B) fluorescent emission spectra of 7−11 in DCM (2.0 × 10−4 M) at room temperature.
around 103 L·mol−1 cm−1, corresponding to the characteristic n
→ π* transitions of the phenanthroline component34 (Figure
2, Table 2). Interestingly, the absorption bands are significantly
for butoxy-substituted analogues 7b−11b bathochromic shifts
to around 380 nm accompanied by a significant hyperchromic
effect (Figure 2A and Figure S4A). The substituent effect was
also observed in fluorescent emission (Figure 2B and Figure
S4B). For example, 9a and 11a show an emission band with
fine structure and the maximum emission wavelengths at 408
and 387 nm, respectively. In contrast, 9b−11b show bell
emission curves with the maximum emission wavelengths
bathochromically shifted to around 430 nm. The substituent
effect can be mainly ascribed to the electronic transition energy
perturbation of phenanthroline caused by the butoxy groups.
This was further supported by the similar substituent effect
observed between 1,10-phenanthroline and 5,6-dibutoxy-1,10-
phenanthroline (Figure S3). The redox property of 7−11 was
investigated by cyclic voltammetry (CV) and differential pulse
voltammetry (DPV). As shown in Table 2 and Figures S6−
S14, in most cases two sequential one-electron reduction
potentials were observed. The first half-wave reduction
potential as measured by DPV is in the range of −2341 to
−2445 mV, which is comparable to 1,10-phenanthroline
(−2437 mV, Figure S5).
Table 2. Summary of Physicochemical Properties of the
a
Macrocycles 7−11
Adsorption band I Adsorption band II
λmax
/
εmax/103
λmax
/
εmax/103
λem
/
E1/
E2/
b
b
nm
M−1·cm−1
nm
M−1·cm−1
nm (mV) (mV)
7b
7c
7d
8b
9a
9b
10b
11a
11b
362
340
340
362
341
362
362
342
361
2.23
1.91
1.91
2.65
c
1.94
3.43
3.37
1.98
378
356
356
380
356
380
380
358
381
0.91
0.54
0.54
1.96
c
1.54
2.10
0.76
1.20
434 −2381 −2601
382 −2393 −2545
397 −2403 −2605
435 −2373 −2609
408 −2417 −2617
432 −2445
d
437 −2365 −2601
387 −2393 −2601
436 −2341
d
a
UV−vis and fluorescent spectra were recorded in DCM (2.0 × 10−4
M) at room temperature. Cyclic voltammograms and differential pulse
voltammograms were performed in CH3CN with a scan rate of 100
mV s−1 and 4 mV s−1, respectively. [n-Bu4N][PF6] (0.1 M) was used
To investigate the capability of tetraoxacalix[2]arene[2]-
phenanthrolines to form dinuclear complexes with Cu2+, single
crystals were cultivated through diffusion of Et2O into the
mixed solution of the macrocycle and Cu(ClO4)2 in DCM/
CH3CN. To our delight crystal structures of dinuclear
complexes 7b-2Cu(II) and 11b-2Cu(II) were obtained
(Figures 3 and 4). In both complexes each Cu2+ ion is
chelated by one phenanthroline along with another equatorial
b
as supporting electrolyte. Half-wave potential determined vs Fc+/Fc.
c
d
Not determined due to the poor solubility. Not determined.
affected by the substituent on phenanthroline (Figure 2 and
Figure S4). While the nonsubstituted macrocycles 9a and 11a
give λmax of the second absorption band at 350 nm, the band
−
Figure 3. Crystal structure of the dinuclear 7b−2Cu(II) complex [Cu2(7b)(μ-OH)(H2O)2(CH3CN)2][(ClO4)3]·CH3CN. (A) Top view (ClO4
anions are omitted). (B) Side view. Hydrogen atoms and nonessential solvent molecules are omitted for clarity. Representative distances: dCu1−Cu2
= 3.67 Å, d−ClO −phenanthroline = 3.10−3.27 Å.
4
D
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−
Figure 4. Crystal structure of the dinuclear 11b-2Cu(II) complex [Cu2(11b)(H2O)4(CH3CN)2](ClO4)4. (A) Top view (ClO4 anions are
omitted). (B) Side view. Hydrogen atoms are omitted for clarity. Representative distance: dCu1−Cu2 = 11.48 Å.
Figure 5. (A) UV−vis spectra of 7b, 7b−2Cu(II) complex, and 7b with addition of 2.0 equiv of Cu(ClO4)2. (B) Titration of 7b by Cu(ClO4)2 in
1:1 acetonitrile/dichloromethane.
acetonitrile and two additional axial O-ligands (H2O or OH−),
forming a distorted square-pyramidal geometry. In 7b-2Cu(II),
due to the compacted macrocyclic skeleton, the two five-
coordinated Cu(II) centers share a OH− bridge in μ2-oxo
configuration (Figure 3). The Cu(II)−Cu(II) distance is 3.66
Å and similar to that in oxygenated hemocyanin (ca. 3.6 Å).37
Upon complexation of Cu(II), the macrocyclic host shows a
dramatic conformational change. In contrast to the flattened
array of phenanthrolines in the free host, in the complex the
macrocycle adopts a twist 1,3-alternate conformation in which
the two phenanthrolines are face-to-face erected, producing a
V-shape cavity with the μ2-OH pointing in the center. One
methane, the absorption intensity at 310−420 nm increased
and a weak band at 600−850 nm was emerged. Notably, the in
situ obtained spectrum is almost identical to that of the 7b−
2Cu(II) crystal complex dissolved in solution, suggesting the
formation of dinuclear Cu(II) complex. For 8b−11b, upon
complexation with Cu(ClO4)2 the UV−vis spectra are
generally similar (Figures S19−S23). From the titration data,
the binding constants (log K1:1 and log K1:2) were determined
by a nonlinear least-squares fit using the Hyperquad2003
program.48 The cooperativity of the stepwise Cu(II)/
phenanthroline complexation was then evaluated according
to the interaction parameter α = 4K1:2/K1:1 (α > 1, positive
cooperativity; α < 1 negative cooperativity; α = 1 no
cooperativity).49 As shown in Table 3, a strong negative
cooperativity (α = 0.0047) was observed for 7b, probably
caused by the strong electrostatic repulsion due to the short
Cu−Cu distance. This repulsion can be reduced with the
increase of Cu−Cu distance due to the longer diphenol linkers
in 8b and 9b and accordingly leads to less negative
cooperativities (α = 0.27 and 0.72 respectively). Surprisingly,
−
ClO4 is included within the cavity and has a short contact
with the phenanthrolines at the O−π plane distances of 3.10−
3.27 Å (Figure 3B). This indicates that the enhanced electron-
deficiency of phenanthroline after coordination with Cu(II)
ion can facilitate the formation of anion−π interactions.19−21
In 11b−2Cu(II), however, due to the long terphenyl linkers,
two discrete five-coordinated Cu(II) centers exist at a long
separation of 11.48 Å (Figure 4). Interestingly, upon
complexation the host turns from the U-shape conformation
(Figure 1E) to a less steric chairlike conformation in order to
accommodate the coordinated acetonitrile and water mole-
cules (Figure 4B). These two examples hence demonstrated
that the structurally tunable tetraoxacalix[2]arene[2]-
phenanthrolines can serve as superior molecular platforms to
access diverse dinuclear metal complex models with distinct
structural characteristics.
Table 3. Binding Constants (log K1:1 and log K1:2) for
a
Dinuclear Cu(II) Complexes
b
7b
8b
9b
10b
11b
log K1:1
log K1:2
α
5.95
3.02
0.0047
5.49
4.32
0.27
4.97
4.22
0.72
5.23
5.33
5.07
4.43
4.60
5.87
c
The complexation of 7b−11b with Cu2+ (as perchlorate
salt) in solution was investigated by means of UV−vis titration.
As shown in Figure 5A, upon addition of 2.0 equiv of
Cu(ClO4)2 to a solution of 7b in 1:1 acetonitrile/dichloro-
a
Obtained from UV−vis titrations in 1:1 acetonitrile/dichloro-
b
methane. The host concentration is 5 × 10−5 M. The host
concentration of 2 × 10−4 M was applied due to the small spectral
c
change. α = 4 K1:2/K1:1
.
E
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Figure 6. (A) XPS, (B) EPR spectra, and (C) CV trace of 7b−2Cu(II) complex.
when the diphenol linker (and hence the separation of the two
phenanthroline coordination moieties) becomes even longer,
unexpected large positive cooperativities were observed for
10b (α = 5.07) and 11b (α = 5.87). Although it is currently
difficult to fully understand such large positive cooperativities,
the self-adjust of the macrocyclic host conformation to
maximize the complexation (allosteric effect) might be one
of the possibilities. Besides, the larger cavity provides space to
accommodate counteranions, which may act as anion bridge
and compensate the electrostatic repulsion between the two
Cu(II) centers. It is worth noting that 7b−11b can also form
dinuclear complexes with other transition metal ions such as
Zn2+, Fe2+, and Cd2+ (Figures S25−S29), with binding
constants in the range of 4.22−5.89 (logK1:1) and 1.39−2.99
(logK1:2), respectively (Table S6).
phenanthroline moiety as revealed by spectroscopic and CV
measurements. They can form a series of dinuclear dicopper
complexes with diverse structure. While the extended linkage
gives two individual metal-coordination centers at a long
separation, the short linkage and constrained macrocyclic
skeleton provide two closed and interrelated metal centers
embedded within a deep cavity. The easy synthesis, the tunable
conformation, and the capability to form well-defined macro-
cycle-metal dinuclear complexes make the oxacalixphenanthro-
lines as superior macrocyclic platforms to access metal-
containing small-molecule enzyme models. The biomimetic
catalysis performance of these macrocycle-metal complexes is
under investigation in the laboratory.
EXPERIMENTAL SECTION
■
The spectroscopic characterization and the redox property
of the prepared dicopper complexes were established by XPS,
EPR, CV, and DPV. The binding energies for Cu2p3/2 are in the
range of 935.1−935.5 eV, which are characteristic of the
Cu(II) state (Figure 6A and Figure S30). As paramagnetic
species, the electron spin signals of these complexes were
clearly observed in EPR spectra recorded from frozen solutions
(Figure 6C and Figure S31). The g∥, g⊥, and A∥ values of the
complexes were calculated and compiled in Table S7. The
order of g∥ > g⊥ > ge (2.0023) indicates a typical axial signature
that the dicopper complexes are either six-coordinated or
distortedly five-coordinated as observed in the X-ray structure,
General Procedure for the Synthesis of 7−11. To a flask
containing Cs2CO3 (2.5 mmol) and dried DMF (10 mL) at 100 °C
was added a solution of 6a (1 mmol) and corresponding diols 1−5 (1
mmol) in DMF (10 mL) through an injection pump during 6 h. The
resulting mixture was heated at 100 °C under Ar with stirring for
another 24 h. The mixture was then cooled to room temperature and
poured into water (150 mL); then HCl was added and the pH was
adjusted to about 2. The white precipitates were collected and
redissolved in DCM (if not soluble, a few drops of trifluoroacetic acid
was added to help dissolve) and dried over anhydrous Na2SO4. After
filtration and removal of solvent, the residue was chromatographed on
a silica gel column with a mixture of DCM and MeOH (100:1 to
20:1) as the eluent to give pure products 7a−11a. For the synthesis of
7b−11b a similar procedure was followed except that the solution of
diols 1−5 was injected into the mixture of 6b and Cs2CO3 in DMF.
7a (white solid, yield 79%). Mp > 300 °C; 1H NMR
(CF3COOD, 400 MHz) δ (ppm) 8.74 (d, J = 9.0 Hz, 4H), 8.03
(s, 4H), 7.77 (t, J = 8.3 Hz, 2H), 7.64 (d, J = 9.0 Hz, 4H), 7.60−7.56
(m, 2H), 7.51 (dd, J = 8.3, J = 1.9 Hz, 4H); 13C NMR (CDCl3, 125
MHz) δ (ppm) 162.5, 155.1, 135.5, 134.7, 129.0, 128.1, 120.3, 118.6.;
IR (KBr) ν 1610, 1586, 1414, 1273; HRMS (ESI+) calcd. for [M +
with electron localized on the dx −y orbital.50,51 Different from
the other complexes, 7b−2Cu(II) gives two sets of electron
spin signals (Table S7). One set might be ascribed to the O-
bridged dicopper structure as observed in the crystal, while the
other set may correspond to a structure where ligand exchange
has occurred. The CV and DPV of the dicopper complexes
were recorded in acetonitrile with tetra-n-butylammonium
hexafluorophosphate as the supporting electrolyte (Figures
S15−S18). The E1/2 (vs Fc/Fc+) values are in the range of
0.352−0.604 V and comparable with other reported Cu-
phenanthroline complexes (Table S7).52 Interestingly, the E1/2
values show no obvious dependence on the length of aromatic
linkages, suggesting the redox property is mainly dominated by
phenathroline ligands.
2
2
+
H]+ (C36H21N4O4 ), 573.1557, found 573.1557. Anal. Calcd for
C36H20N4O4·H2O: C, 73.21; H, 3.75; N, 9.49. Found: C, 73.06; H,
3.56; N, 9.26.
7b (white solid, yield 48%). Mp 269−270 °C; 1H NMR
(CDCl3, 500 MHz) δ (ppm) 8.55 (d, J = 8.7 Hz, 4H), 7.44 (t, J = 8.2
Hz, 2H), 7.32−7.24 (m, 6H), 6.98 (s, 2H), 4.23 (t, J = 6.6 Hz, 8H),
1.93−1.82 (m, 8H), 1.66−1.54 (m, 8H), 1.04 (t, J = 7.4 Hz, 12H);
13C NMR (CDCl3, 100 MHz) δ (ppm) 160.7, 154.5, 141.5, 141.0,
134.5, 129.3, 123.6, 116.4, 114.3, 113.8, 73.9, 32.6, 19.6, 14.1; IR
(KBr) ν 1609, 1592, 1457, 1346, 1286, 1237; HRMS (ESI+) calcd. for
CONCLUSION
■
+
[M + H]+ (C52H53N4O8 ), 861.3858, found 861.3832. Anal. Calcd for
In conclusion, we have reported the first examples of
phenanthroline-containing oxacalixaromatics that were con-
veniently synthesized through a one-pot strategy. The interplay
between heteroatoms, phenanthroline, and aromatic linkages
plays crucial roles on regulating the conformation of these
macrocycles. The resulting tetraoxacalix[2]arene[2]-
phenanthrolines show typical physicochemical property of
C52H52N4O8: C, 72.54; H, 6.09; N, 6.51. Found: C, 72.48; H, 6.10; N,
6.54. A high quality single crystal for X-ray diffraction analysis was
obtained by slow evaporation of a DCM/MeOH solution.
7c (white solid, yield 20%). Mp 278−280 °C; 1H NMR
(CDCl3, 400 MHz) δ (ppm) 8.19 (d, J = 8.6 Hz, 4H), 7.78 (d, J = 2.1
Hz, 4H), 7.66 (s, 4H), 7.29 (s, 2H), 7.24 (d, J = 8.7 Hz, 5H), 4.35 (t,
J = 6.5 Hz, 4H), 1.80−1.54 (m, 4H), 1.46−1.24 (m, 4H); 13C NMR
F
DOI: 10.1021/acs.inorgchem.8b02039
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
(CDCl3, 125 MHz) δ (ppm) 165.7, 161.1, 155.0, 143.5, 139.9, 132.0,
126.4, 124.3, 117.9, 117.4, 114.2, 65.1, 30.9, 19.4, 13.8; IR (KBr) ν
2958, 1718, 1589, 1274, 1216; HRMS (APCI+) calcd. for [M + H]+
(C46H37N4O8 ), 773.2611, found 773.2587. Anal. Calcd for
C46H36N4O8: C, 71.49; H, 4.70; N, 7.25. Found: C, 71.11; H, 4.49;
N, 7.22.
1.95−1.84 (m, 8H), 1.66−1.57 (m, 8H), 1.04 (t, J = 7.4 Hz, 12H);
13C NMR (CDCl3, 125 MHz) δ (ppm) 194.1, 160.8, 157.3, 141.8,
140.9, 134.9, 133.5, 131.9, 123.7, 120.3, 114.2, 74.0, 32.6, 19.6, 14.2;
IR (KBr) ν 1640, 1592, 1346, 1243; HRMS (APCI+) calcd. for [M +
H]+ (C66H61N4O10+), 1069.4382, found 1069.4367. Anal. Calcd for
C66H60N4O10: C, 74.14; H, 5.66; N, 5.24. Found: C, 74.12; H, 5.76;
N, 5.29. A high quality single crystal for X-ray diffraction analysis was
obtained by diffusion of Et2O into a CHCl3 solution.
+
7d (white solid, yield 47%). Mp 292−293 °C; 1H NMR
(CDCl3, 400 MHz) δ (ppm) 8.23 (d, J = 8.6 Hz, 4H), 7.84 (d, J = 2.1
Hz, 4H), 7.71 (s, 4H), 7.30 (d, J = 7.2 Hz, 4H), 7.26 (d, J = 8.6 Hz,
4H), 7.16 (d, J = 2.3 Hz, 2H), 7.12 (t, J = 7.4 Hz, 2H), 6.92 (t, J = 7.6
Hz, 4H), 5.39 (s, 4H); 13C NMR (CDCl3, 100 MHz) δ (ppm) 165.6,
161.2, 154.9, 143.6, 139.9, 136.3, 131.3, 128.2, 127.7, 127.4, 126.4,
124.4, 118.4, 117.5, 114.3, 66.8; IR (KBr) ν 3034, 1721, 1589, 1275,
1
11a (white solid, yield 31%). Mp > 300 °C; H NMR (CDCl3,
400 MHz) δ (ppm) 8.24 (d, J = 8.6 Hz, 4H), 7.77−7.72 (m, 8H),
7.72 (s, 4H), 7.43−7.37 (m, 8H), 7.34 (d, J = 8.6 Hz, 4H), 7.30 (d, J
= 1.8 Hz, 2H), 7.23 (t, J = 1.5 Hz, 2H), 7.21 (d, J = 1.7 Hz, 2H), 7.14
(dd, J = 8.5, 6.6 Hz, 2H); 13C NMR (CDCl3, 125 MHz) δ (ppm)
161.8, 153.9, 143.4, 140.5, 139.8, 137.2, 128.7, 128.1, 126.1, 125.5,
125.3, 124.2, 121.0, 114.6; IR (KBr) ν 1615, 1598, 1459, 1286;
+
1217; HRMS (ESI+) calcd. for [M + H]+ (C76H49N6O6 ), 841.2293,
found 841.2295. Anal. Calcd for C76H48N6O6·0.5H2O: C, 73.49; H,
3.91; N, 6.59. Found: C, 73.49; H, 3.87; N, 6.65. A high quality single
crystal for X-ray diffraction analysis was obtained by diffusion of Et2O
into a DMF solution.
+
HRMS (ESI+) calcd. for [M + H]+ (C60H37N4O4 ), 877.2809, found
877.2795. Anal. Calcd for C60H36N4O4·H2O: C, 80.52; H, 4.14; N,
6.39. Found: C, 80.35; H, 4.21; N, 6.20. A high quality single crystal
for X-ray diffraction analysis was obtained by diffusion of Et2O into a
DMF solution.
8a (white solid, yield 17%). Mp > 300 °C; 1H NMR
(CF3COOD, 400 MHz) δ (ppm) 8.74 (d, J = 9.0 Hz, 4H), 8.10−
8.04 (m, 8H), 7.66 (d, J = 9.0 Hz, 4H), 7.64−7.59 (m, 8H); 13C
NMR (CF3COOD, 100 MHz) δ (ppm) 162.7, 152.0, 147.9, 137.4,
135.2, 133.3, 132.4, 128.6, 127.8, 120.9, 120.9, 119.6, 119.0; IR (KBr)
ν 1600, 1457, 1331, 1278; HRMS (APCI+) calcd. for [M + H]+
11b (white solid, yield 31%). Mp 217−218 °C; 1H NMR
(CDCl3, 300 MHz) δ (ppm) 8.56 (d, J = 8.8 Hz, 4H), 7.76−7.68 (m,
8H), 7.41−7.36 (m, 8H), 7.34 (d, J = 8.8 Hz, 4H), 7.29 (d, J = 1.8
Hz, 2H), 7.22 (t, J = 1.8 Hz, 2H), 7.20 (d, J = 1.7 Hz, 2H), 7.13 (dd, J
= 8.8, 6.2 Hz, 2H), 4.25 (t, J = 6.6 Hz, 8H), 1.96−1.82 (m, 8H),
1.68−1.54 (m, 8H), 1.04 (t, J = 7.4 Hz, 12H); 13C NMR (CDCl3, 100
MHz) δ (ppm) 161.2, 153.9, 141.7, 140.9, 140.5, 137.2, 134.5, 128.7,
128.1, 125.5, 125.3, 123.3, 120.9, 114.4, 73.9, 32.7, 19.6, 14.2; IR
(KBr) ν 1609, 1592, 1346, 1286, 1237; HRMS (ESI+) calcd. for [M +
+
(C44H25N4O4 ), 673.1870, found 673.1858. Anal. Calcd for
C44H24N4O4·0.5H2O: C, 77.52; H, 3.70; N, 8.22. Found: C, 77.72;
H, 3.56; N, 8.35.
8b (white solid, yield 45%). Mp 293−294 °C; 1H NMR
(CDCl3, 400 MHz) δ (ppm) 8.56 (d, J = 8.8 Hz, 4H), 7.89 (d, J = 8.9
Hz, 4H), 7.54 (d, J = 8.8 Hz, 4H), 7.35 (s, 4H), 7.31 (d, J = 8.8 Hz,
4H), 4.24 (t, J = 6.6 Hz, 8H), 1.96−1.80 (m, 8H), 1.68−1.55 (m,
8H), 1.04 (t, J = 7.4 Hz, 12H); 13C NMR (CDCl3, 100 MHz) δ
(ppm) 160.9, 151.7, 141.6, 141.1, 135.3, 134.5, 128.8, 127.6, 123.5,
119.8, 116.7, 114.3, 73.9, 32.7, 19.6, 14.2; IR (KBr) ν 1614, 1596,
+
H]+ (C76H69N4O8 ), 1165.5110, found 1165.5119. Anal. Calcd for
C76H68N4O8·H2O: C, 77.14; H, 5.96; N, 4.81. Found: C, 77.14; H,
5.82; N, 4.75. A high quality single crystal for X-ray diffraction analysis
was obtained by slow evaporation of a CHCl3 solution.
+
1347, 1288, 1241; HRMS (ESI+) calcd. for [M + H]+ (C60H57N4O8 ),
ASSOCIATED CONTENT
* Supporting Information
■
961.4171, found 961.4148. Anal. Calcd for C60H56N4O8: C, 74.98; H,
5.87; N, 5.83. Found: C, 74.75; H, 5.97; N, 5.93. A high quality single
crystal for X-ray diffraction analysis was obtained by slow evaporation
of a CHCl3 solution.
S
The Supporting Information is available free of charge on the
ACS Publications website at DOI: 10.1021/acs.inorg-
chem.8b02039.
9a (white solid, yield 21%). Mp > 300 °C; 1H NMR
(CF3COOD, 500 MHz) δ (ppm) 8.69 (d, J = 9.0 Hz, 4H), 8.01
(s, 4H), 7.62 (d, J = 8.9 Hz, 4H), 7.30−7.20 (m, 16H); 13C NMR
(CF3COOD, 100 MHz) δ (ppm) 163.8, 157.6, 148.8, 147.7, 135.3,
128.5, 127.7, 124.1, 122.9, 118.7; IR (KBr) ν 1606, 1489, 1457, 1338,
1H and 13C NMR spectra of all compounds, XPS,
spectroscopic and redox curves, and crystallographic
data (PDF)
+
1284; HRMS (APCI+) calcd. for [M + H]+ (C48H28N4O4 ),
Accession Codes
757.2082, found 757.2068. Anal. Calcd for C48H28N4O4·H2O: C,
74.41; H, 3.90; N, 7.23. Found: C, 74.10; H, 3.75; N, 7.34.
CCDC 1856273−1856281 contain the supplementary crys-
tallographic data for this paper. These data can be obtained
free of charge via www.ccdc.cam.ac.uk/data_request/cif, or by
emailing data_request@ccdc.cam.ac.uk, or by contacting The
Cambridge Crystallographic Data Centre, 12 Union Road,
Cambridge CB2 1EZ, UK; fax: +44 1223 336033.
9b (white solid, yield 36%). Mp 299−300 °C; 1H NMR
(CDCl3, 400 MHz) δ (ppm) 8.53 (d, J = 8.8 Hz, 4H), 7.42−7.34 (m,
8H), 7.28 (d, J = 8.8 Hz, 4H), 7.10−7.03 (m, 8H), 4.23 (t, J = 6.6 Hz,
8H), 1.94−1.81 (m, 8H), 1.66−1.51 (m, 8H), 1.03 (t, J = 7.4 Hz,
12H); 13C NMR (CDCl3, 100 MHz) δ (ppm) 161.2, 153.7, 149.2,
141.4, 140.8, 134.4, 123.2, 122.2, 119.6, 114.1, 73.8, 32.5, 19.5, 14.0;
IR (KBr) ν 1615, 1598, 1349, 1235; HRMS (APCI+) calcd. for [M +
H]+ (C64H61N4O10+), 1145.4382, found 1145.4359. Anal. Calcd for
C64H60N4O10: C, 73.55; H, 5.79; N, 5.36. Found: C, 73.31; H, 5.99;
N, 5.43. A high quality single crystal for X-ray diffraction analysis was
obtained by slowly cooling of a hot DMF solution.
AUTHOR INFORMATION
Corresponding Authors
*E-mail: qiqiangw@iccas.ac.cn.
*E-mail: dxwang@iccas.ac.cn.
■
10a (white solid, yield 16%). Mp > 300 °C; 1H NMR
(CF3COOD, 400 MHz) δ (ppm) 8.82 (d, J = 9.0 Hz, 4H), 8.13 (s,
4H), 7.93 (d, J = 8.6 Hz, 8H), 7.75 (d, J = 9.0 Hz, 4H), 7.50 (d, J =
8.5 Hz, 8H); 13C NMR (CF3COOD, 125 MHz) δ (ppm) 199.9,
162.6, 157.7, 148.4, 136.5, 136.2, 135.2, 129.0, 128.3, 122.7, 119.4; IR
(KBr) ν 1646, 1592, 1457, 1335, 1274; HRMS (APCI+) calcd. for [M
ORCID
Yu-Fei Ao: 0000-0002-9415-2181
Qi-Qiang Wang: 0000-0001-5988-1293
De-Xian Wang: 0000-0002-9059-5022
Notes
+
+ H]+ (C50H29N4O6 ), 781.2082, found 781.2073. Anal. Calcd for
The authors declare no competing financial interest.
C50H28N4O6·2H2O: C, 73.52; H, 3.95; N, 6.86. Found: C, 73.57; H,
3.63; N, 6.88.
ACKNOWLEDGMENTS
We thank the National Natural Science Foundation of China
(21772203, 21761132024, 21502200, 21521002) and Chinese
10b (white solid, yield 13%). Mp > 300 °C; 1H NMR (CDCl3,
500 MHz) δ (ppm) 8.58 (d, J = 8.7 Hz, 4H), 7.70−7.63 (m, 8H),
7.43−7.36 (m, 8H), 7.34 (d, J = 8.7 Hz, 4H), 4.25 (t, J = 6.7 Hz, 8H),
■
G
DOI: 10.1021/acs.inorgchem.8b02039
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Article
and their Directing Effect on Molecular Assembly. Chem. - Eur. J.
2010, 16, 13053−13057.
(22) Hu, S.-Z.; Chen, C.-F. Triptycene-Derived Oxacalixarenes as
New Wheels for the Synthesis of [2]Rotaxanes: Acid-Base- and Metal-
Ion-Switchable Complexation Processes. Chem. - Eur. J. 2011, 17,
5424−5431.
(23) Ma, M.-L.; Li, X.-Y.; Wen, K. Coordination-Driven Self-
Assembly of a Discrete Molecular Cage and an Infinite Chain of
Coordination Cages Based on ortho-Linked Oxacalix[2]benzene[2]-
pyrazine and Oxacalix[2]arene[2]pyrazine. J. Am. Chem. Soc. 2009,
131, 8338−8339.
(24) He, Q.; Han, Y.; Wang, Y.; Huang, Z.-T.; Wang, D.-X. Size-
Regulable Vesicles Based on Anion-π Interactions. Chem. - Eur. J.
2014, 20, 7486−7491.
(25) He, Q.; Huang, Z.-T.; Wang, D.-X. Regulated Assemblies and
Anion Responsive Vesicles Based on 1,3-Alternate Oxacalix[2]-
arene[2]triazene Amphiphiles. Chem. Commun. 2014, 50, 12985−
12988.
(26) He, Q.; Tuo, D.-H.; Ao, Y.-F.; Wang, Q.-Q.; Wang, D.-X.
Vesicles Constructed with Chiral Amphiphilic Oxacalix[2]arene[2]-
triazine Derivatives for Enantioselective Recognition of Organic
Anions. ACS Appl. Mater. Interfaces 2018, 10, 3181−3185.
(27) Xu, R.-B; Hou, B.-Y; Wang, D.-X; Wang, M.-X. Synthesis and
Self-Assembly of Novel Oxacalix[2]arene[2]triazine Amphiphiles. Sci.
China: Chem. 2016, 59, 1306−1310.
(28) Xu, R.-B.; Wang, Q.-Q.; Ao, Y.-F.; Li, Z.-Y.; Huang, Z.-T.;
Wang, D.-X. Anionic Head Containing Oxacalix[2]arene[2]triazines:
Synthesis and Anion-π-Directed Self-Assembly in Solution and Solid
State. Org. Lett. 2017, 19, 738−741.
(29) He, Q.; Ao, Y.-F.; Huang, Z.-T.; Wang, D.-X. Self-Assembly and
Disassembly of Vesicles as Controlled by Anion-π Interactions. Angew.
Chem., Int. Ed. 2015, 54, 11785−11790.
Academy of Sciences (QYZDJ-SSW-SLH023) for financial
support. Q.-Q.W. also thanks the Thousand Young Talents
Program for support.
REFERENCES
■
(1) Comprehensive Supramolecular Chemistry; Lehn, J.-M., Atwood, J.
L., Davies, J. E. D., MacNicol, D. D., Vogtle, F., Eds.; Pergamon,
Oxford, UK, 1996.
̈
(2) Gutsche, C. D. Calixarenes Revisited; The Royal Society of
Chemistry, Cambridge, 1998.
(3) Calixarenes and Beyond; Neri, P., Sessler, J. L., Wang, M.-X., Eds.;
Springer, 2016.
(4) Wang, M.-X. Heterocalixaromatics, New Generation Macrocyclic
Host Molecules in Supramolecular Chemistry. Chem. Commun. 2008,
4541−4551.
(5) Wang, M.-X. Nitrogen and Oxygen Bridged Calixaromatics:
Synthesis, Structure, Functionalization, and Molecular Recognition.
Acc. Chem. Res. 2012, 45, 182−195.
(6) Maes, W.; Dehaen, W. Oxacalix[n](het)arenes. Chem. Soc. Rev.
2008, 37, 2393−2402.
(7) Tsue, H.; Ishibashi, K.; Tamura, R. Azacalixarene: A New Class
in the Calixarene Family. Top. Heterocycl. Chem. 2008, 17, 73−96.
(8) Morohashi, N.; Narumi, F.; Iki, N.; Hattori, T.; Miyano, S.
Thiacalixarenes. Chem. Rev. 2006, 106, 5291−5316.
̈
(9) Konig, B.; Fonseca, M. H. Heteroatom-Bridged Calixarenes. Eur.
J. Inorg. Chem. 2000, 2000, 2303−2310.
(10) Chen, C.-F. Novel Triptycene-Derived Hosts: Synthesis and
Their Applications in Supramolecular Chemistry. Chem. Commun.
2011, 47, 1674−1688.
(11) Wang, M.-X.; Yang, H.-B. A General and High Yielding
Fragment Coupling Synthesis of Heteroatom-Bridged Calixarenes and
the Unprecedented Examples of Calixarene Cavity Fine-Tuned by
Bridging Heteroatoms. J. Am. Chem. Soc. 2004, 126, 15412−15422.
(12) Wang, M.-X.; Zhang, X.-H.; Zheng, Q.-Y. Synthesis, Structure,
and [60]Fullerene Complexation Properties of Azacalix[m]arene[n]-
pyridines. Angew. Chem., Int. Ed. 2004, 43, 838−842.
(30) Accorsi, G.; Listorti, A.; Yoosaf, K.; Armaroli, N. 1,10-
Phenanthrolines: Versatile Building Blocks for Luminescent Mole-
cules, Materials and Metal Complexes. Chem. Soc. Rev. 2009, 38,
1690−1700.
(31) Bagal, D. B.; Kachkovskyi, G.; Knorn, M.; Rawner, T.; Bhanage,
B. M.; Reiser, O. Trifluoromethylchlorosulfonylation of Alkenes:
Evidence for an Inner-Sphere Mechanism by a Copper Phenanthro-
line Photoredox Catalyst. Angew. Chem., Int. Ed. 2015, 54, 6999−
7002.
(13) Van Rossom, W.; Maes, W.; Kishore, L.; Ovaere, M.; Van
Meervelt, L.; Dehaen, W. Efficient Post-Macrocyclization Function-
alizations of Oxacalix[2]arene[2]pyrimidines. Org. Lett. 2008, 10,
585−588.
(14) Zhang, C.; Chen, C.-F. Triptycene-Based Expanded Oxacalix-
arenes: Synthesis, Structure, and Tubular Assemblies in the Solid
State. J. Org. Chem. 2007, 72, 3880−3888.
(32) Bencini, A.; Lippolis, V. 1,10-Phenanthroline: A Versatile
Building Block for the Construction of Ligands for Various Purposes.
Coord. Chem. Rev. 2010, 254, 2096−2180.
(33) McSkimming, A.; Shrestha, S.; Bhadbhade, M. M.; Thordarson,
P.; Colbran, S. B. Macrocyclic Bis(phenanthroline-pyrrole): a
Convenient One-Pot Synthesis, Structure(s), Spectroscopic, and
Redox Properties, and the Binding of Amine Guests, Protons, and
Lanthanide Ions. Chem. - Asian J. 2014, 9, 136−145.
(34) Summers, L. A. The Phenanthrolines. In Advances in
Heterocyclic Chemistry Katritzky, A. R., Boulton, A. J., Eds.; Academic
Press, 1978; Vol. 22, pp 1−69.
(35) Sun, C.-L.; Li, H.; Yu, D.-G.; Yu, M.; Zhou, X.; Lu, X.-Y.;
Huang, K.; Zheng, S.-F.; Li, B.-J.; Shi, Z.-J. An Efficient Organo-
catalytic Method for Constructing Biaryls through Aromatic C-H
Activation. Nat. Chem. 2010, 2, 1044−1049.
(36) Kuritani, M.; Tashiro, S.; Shionoya, S. Heterodinuclear Metal
Arrangement in a Flat Macrocycle with Two Chemically- Equivalent
Metal Chelating Sites. Inorg. Chem. 2012, 51, 1508−1515.
(37) Mirica, L. M.; Ottenwaelder, X.; Stack, T. D. P. Structure and
Spectroscopy of Copper-Dioxygen Complexes. Chem. Rev. 2004, 104,
1013−1045.
(15) Katz, J. L.; Geller, B. J.; Conry, R. R. Synthesis of
Oxacalixarenes Incorporating Nitrogen Heterocycles: Evidence for
Thermodynamic Control. Org. Lett. 2006, 8, 2755−2758.
(16) Katz, J. L.; Geller, B. J.; Foster, P. D. Oxacalixarenes and
Oxacyclophanes Containing 1,8-Naphthyridines: A New Class of
Molecular Tweezers with Concave-Surface Functionality. Chem.
Commun. 2007, 1026−1028.
(17) Fa, S.-X.; Wang, L.-X.; Wang, D.-X.; Zhao, L.; Wang, M.-X.
Synthesis, Structure, and Fullerene-Complexing Property of
Azacalix[6]aromatics. J. Org. Chem. 2014, 79, 3559−3571.
(18) Wang, Q.-Q.; Wang, D.-X.; Wang, M.-X. Formation and
Conformational Conversion of Flattened Partial Cone Oxygen
Bridged Calix[2]arene[2]triazines. Org. Lett. 2007, 9, 2847−2850.
(19) Wang, D.-X.; Zheng, Q.-Y.; Wang, Q.-Q.; Wang, M.-X. Halide
Recognition by Tetraoxacalix[2]arene[2]triazine Receptors: Con-
current Noncovalent Halide-π and Lone-Pair-π Interactions in Host-
Halide-Water Ternary Complexes. Angew. Chem., Int. Ed. 2008, 47,
7485−7488.
(20) Wang, D.-X.; Wang, M.-X. Anion-π Interactions: Generality,
Binding Strength, and Structure. J. Am. Chem. Soc. 2013, 135, 892−
897.
(21) Wang, D.-X.; Wang, Q.-Q.; Han, Y.; Wang, Y.; Huang, Z.-T.;
Wang, M.-X. Versatile Anion−π Interactions Between Halides and a
Conformationally Rigid Bis(tetraoxacalix[2]arene[2]triazine) Cage
(38) Lewis, E. A.; Tolman, W. B. Reactivity of Dioxygen-Copper
Systems. Chem. Rev. 2004, 104, 1047−1076.
(39) Solomon, E. I.; Szilagyi, R. K.; George, S. D.; Basumallick, L.
Electronic Structures of Metal Sites in Proteins and Models:
Contributions to Function in Blue Copper Proteins. Chem. Rev.
2004, 104, 419−458.
H
DOI: 10.1021/acs.inorgchem.8b02039
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
(40) Saracini, C.; Ohkubo, K.; Suenobu, T.; Meyer, G. J.; Karlin, K.
D.; Fukuzumi, S. Laser-Induced Dynamics of Peroxodicopper(ii)
Complexes Vary with the Ligand Architecture. One-Photon Two-
Electron O2 Ejection and Formation of Mixed-Valent CuICuII-
Superoxide Intermediates. J. Am. Chem. Soc. 2015, 137, 15865−
15874.
(41) Cowley, R. E.; Tian, L.; Solomon, E. I. Mechanism of O2
Activation and Substrate Hydroxylation in Noncoupled Binuclear
Copper Monooxygenases. Proc. Natl. Acad. Sci. U. S. A. 2016, 113,
12035−12040.
(42) Molenveld, P.; Engbersen, F. J.; Reinhoudt, D. N. Dinuclear
Metallo-Phosphodiesterase Models: Application of Calix[4]arenes as
Molecular Scaffolds. Chem. Soc. Rev. 2000, 29, 75−86.
(43) Fenton, D. E. Metallobiosites and their Synthetic Analogues-A
Belief in Synergism 1997−1998 Tilden Lecture. Chem. Soc. Rev. 1999,
28, 159−168.
(44) Li, L.; Sarjeant, A. A. N.; Vance, M. A.; Zakharov, L. N.;
Rheingold, A. L.; Solomon, E. I.; Karlin, K. D. Exogenous Nitrile
Substrate Hydroxylation by a New Dicopper-Hydroperoxide Com-
plex. J. Am. Chem. Soc. 2005, 127, 15360−15361.
(45) Cao, R.; Elrod, L. T.; Lehane, R. L.; Kim, E.; Karlin, K. D. A
Peroxynitrite Dicopper Complex: Formation via Cu-NO and Cu-O2
Intermediates and Reactivity via O-O Cleavage Chemistry. J. Am.
Chem. Soc. 2016, 138, 16148−16158.
(46) Le Poul, N.; Le Mest, Y.; Jabin, I.; Reinaud, O. Supramolecular
Modeling of Mono-Copper Enzyme Active Sites with Calix[6]arene-
Based Funnel Complexes. Acc. Chem. Res. 2015, 48, 2097−2106.
(47) Wang, X.-D.; Wang, D.-X.; Huang, Z.-T.; Wang, M.-X. One-Pot
Synthesis of Oxygen and Nitrogen-Bridged Calix[2]arene[2]triazines.
Supramol. Chem. 2014, 26, 601−606.
(48) Gans, P.; Sabatini, A.; Vacca, A. Investigation of Equilibria in
Solution. Determination of Equilibrium Constants with the HYPER-
QUAD Suite of Programs. Talanta 1996, 43, 1739−1753.
(49) Howe, E. N. W.; Bhadbhade, M.; Thordarson, P. Cooperativity
and Complexity in the Binding of Anions and Cations to a Tetratopic
Ion-Pair Host. J. Am. Chem. Soc. 2014, 136, 7505−7516.
(50) Daravath, S.; Kumar, M. P.; Rambabu, A.; Vamsikrishna, N.;
Shivaraj, N. G. Design, Synthesis, Spectral Characterization, DNA
Interaction and Biological Activity Studies of Copper(II), Cobalt(II)
and Nickel(II) Complexes of 6-Amino Benzothiazole Derivatives. J.
Mol. Struct. 2017, 1144, 147−158.
(51) Lee, Y.; Lee, D.-H.; Park, G. Y.; Lucas, H. R.; Narducci
Sarjeant, A. A.; Kieber-Emmons, M. T.; Vance, M. A.; Milligan, A. E.;
Solomon, E. I.; Karlin, K. D. Sulfur Donor Atom Effects on
Copper(I)/O2 Chemistry with Thioanisole Containing Tetradentate
N3S ligand leading to μ-1,2-Peroxo-Dicoper(II) Species. Inorg. Chem.
2010, 49, 8873−8885.
(52) Rorabacher, D. B. Electron Transfer by Copper Centers. Chem.
Rev. 2004, 104, 651−698.
I
DOI: 10.1021/acs.inorgchem.8b02039
Inorg. Chem. XXXX, XXX, XXX−XXX