Self-assembly of [M8L4] and [M4L 2] fluorescent metallomacrocycles with carbazole-based dipyrazole ligands

Article abstract of DOI:10.1021/ic202407b

Fluorescent carbazole-based dipyrazole ligands (H2L1-4)were employed to coordinate with dipalladium corners ([(phen)₂Pd₂(NO ₃)₂](NO₃)₂, [(dmbpy) ₂Pd₂(NO₃)₂](NO₃) ₂, or [(15-crown-5-phen)₂Pd₂(NO ₃)₂](NO₃)₂, where phen = 1,10-phenanthroline and dmbpy = 4,4'-dimethyl-2,2'-bipyridine, in aqueous solution to afford a series of positively charged [M₈L ₄]⁸⁺ or [M₄L₂]⁴⁺ multimetallomacrocycles with remarkable water solubility. Their structures were characterized by 1H NMR spectroscopy, electrospray ionization mass spectrometry, and elemental analysis and in the cases of 1·8BF₄ -([(phen)₈Pd₈L_1·4](BF₄) ₈), and 3·4BF₄ -([(phen)₄Pd ₄L_2·2](BF₄)4)by single-crystal X-ray diffraction analysis. Complexes 3-8 are square-type hybrid metallomacrocycles, while complexes 1 and 2 exhibit folding cyclic structures. Interestingly, in singlecrystal structures of 1·8BF₄ -and 3·4BF ₄ -, BF₄ -anions are trapped in the dipalladium clips through anion-π interaction. The luminescence properties and interaction toward anions of these metallomacrocycles were discussed.

Full text of DOI:10.1021/ic202407b

Article
pubs.acs.org/IC
Self-Assembly of [M8L4] and [M4L2] Fluorescent Metallomacrocycles
with Carbazole-Based Dipyrazole Ligands
Lin Qin, Liao-Yuan Yao, and Shu-Yan Yu*
Laboratory for Self-Assembly Chemistry, Department of Chemistry, Renmin University of China, Beijing 100872, People’s Republic
of China
S
* Supporting Information
ABSTRACT: Fluorescent carbazole-based dipyrazole ligands (H2L1−4
)
were employed to coordinate with dipalladium corners
([(phen)2Pd2(NO3)2](NO3)2, [(dmbpy)2Pd2(NO3)2](NO3)2, or [(15-
crown-5-phen)2Pd2(NO3)2](NO3)2, where phen = 1,10-phenanthroline
and dmbpy = 4,4′-dimethyl-2,2′-bipyridine, in aqueous solution to afford a
series of positively charged [M8L4]8+ or [M4L2]4+ multimetallomacrocycles
with remarkable water solubility. Their structures were characterized by 1H
NMR spectroscopy, electrospray ionization mass spectrometry, and
elemental analysis and in the cases of 1·8BF4− ([(phen)8Pd8L1 ](BF4)8),
4
and 3·4BF4− ([(phen)4Pd4L2 ](BF4)4) by single-crystal X-ray diffraction
2
analysis. Complexes 3−8 are square-type hybrid metallomacrocycles, while
complexes 1 and 2 exhibit folding cyclic structures. Interestingly, in single-
crystal structures of 1·8BF4− and 3·4BF4−, BF4− anions are trapped in the
dipalladium clips through anion−π interaction. The luminescence properties and interaction toward anions of these
metallomacrocycles were discussed.
indicating that the folding [M8L4]8+ structure presented
INTRODUCTION
■
interaction with an SCN− anion.
With the development of the field of self-assembly of
supramolecular coordination complexes,1 considerable research
interest has been devoted to constructing well-defined
coordination or organometallic supramolecular architectures
with novel structures2−4 and promising applications in guest
inclusion,5 catalysis,6 luminescence,7,8 and anion complexation.9
Owing to the important roles that anions play in chemistry,
biology, and environment, great efforts have been made in the
design and synthesis of receptors for anions, most of which are
capable of interacting with anions through hydrogen bonds in
organic systems and other intramolecular and intermolecular
interactions.9 To the best of our knowledge, although chemists
have showed increasing interest in sensing anions based on
metal−organic compounds,10 self-assembled metallomacro-
cycles utilized to interact with anion selectivity in aqueous
solution are rare. Recently, we developed a metal-directed self-
assembly approach to constructing supramolecular metal-
lomacrocycles with good water solubility,11,12 some of which
show potential application in the complexation of anions.11
Herein, by employing functional dipyrazoles13,14 with
fluorescent carbazole groups to self-assemble with different
dipalladium clips, we synthesized a series of square-type hybrid
[M4L2]4+ and folding [M4L2]4+ metallomacrocycles, especially
obtaining an unprecedented [M8L4]8+ metallomacrocycle with a
folding structure in aqueous solution. The properties for
luminescent metallomacrocycles in anion interaction were
studied through UV−vis, fluorescent, and NMR experiments,
RESULT AND DISCUSSION
■
Self-assembly and Characterization of the [M8L4]8+
Metallomacrocycle. As shown in Scheme 1,
[(phen)2Pd2(NO3)2](NO3)2] was treated with a suspension
containing 1 equiv of H2L1 in H2O (1 mL) and acetone (0.5
mL) at room temperature. After stirring for 2 h, the mixture
was heated at 60 °C for another 24 h. The resulting yellow
solution was then filtered and the clear filtrate was
concentrated, leading to the formation of the positively charged
folding metallomacrocycle 1·8NO3−. The BF4− and PF6− salts
were prepared by anion exchange with an excess of KBF4 and
KPF6, respectively.
The H NMR spectrum of 1·8PF6− (the PF6− salt of 1) is
1
shown in Figure 1; it reveals proton resonances of the pyrazole
groups of the ligand (L1) at 7.25 and 6.95 ppm, which is
different from the free dipyrazole ligand H2L1, which shows
only one singlet at 7.18 ppm. Furthermore, the signals of most
original homotopic protons split into several peaks, except
protons of methyl (methyl H5) of the ligand, which indicates
that these protons are in distinct chemical environments from
each other in metallomacrocycles. The above phenomenon
indicates a low-symmetrical folding architecture, with most
Received: November 8, 2011
Published: February 2, 2012
© 2012 American Chemical Society
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Scheme 1. Self-Assembly of the Folding [M8L4]8+ Metallomacrocycle
Figure 1. 1H NMR spectrum of 1·8PF6− in CD3CN, 25 °C, Si(CH3)4.
protons rigidly located, as further confirmed by X-ray structure
analysis (see below).
Figure 2. ESI-MS spectrum of 1·8PF6− in CH3CN: isotopic
distribution of the species [1·5PF6]3+.
The formation of the [M8L4]8+ metallomacrocycle was
further demonstrated by an electrospray ionization mass
spectrometry (ESI-MS) study, where multiply charged
molecular ions corresponding to intact macrocycles were
observed. The multiply charged ion of 1 was observed at m/z
1602.33, which is assigned to [1·5PF6−]3+ (Figure 2).
Finally, the formation of the [M8L4]8+ metallomacrocycle was
confirmed by the single-crystal X-ray structure study of
1·8BF4−. Single crystals of 1·8BF4− were obtained by the
vapor diffusion of diethyl ether into its acetonitrile solution.
within each corner indicate that there is no π−π-stacking
interaction between them. This conformation also creates an
“open clip” disposition for the square-planar environment of
the two Pd atoms. The Pd1···Pd2 and Pd3···Pd4 separations at
3.087 and 3.178 Å are in the range of typical Pd···Pd
interactions (2.60−3.30 Å).15 In the dipalladium corners, the
dihedral angles between pyrazole planes N9−N10 and N14−
N15 and between N12−N13 and N17−N18 are 77.8° and
62.5°, respectively. All of the bond lengths of Pd−N are around
2.00 Å (Table S1 in the Supporting Information). Within one
molecule, two carbazole planes are on one side, while the other
two are on the opposite side, and the distance between the
N16−C73−C74 and N11−C55−C56 planes is short (3.574
Å), resulting in a long-and-narrow cavity. Interestingly, the
Complex 1·8BF4− crystallizes in the triclinic space group P1. As
̅
shown in Figure 3, the crystal structure analysis reveals the
folding metallomacrocyclic structure with four carbazole-based
dipyrazole ligands bridged with four [(phen)PdII]2 clips. The
large dihedral angles (63.4° and 60.5°) of the (phen)PdII planes
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Figure 3. ORTEP diagrams of the molecular structure of 1·8BF4−: (a) top view; (b) side view. Thermal ellipsoids are shown at the 30% probability
level. The remaining counteranions are omitted for clarity.
structure of 1·8BF4− traps two BF4− anions through anion−π
interaction into the cliplike cavity formed by the (phen)Pd1
and (phen)Pd2 planes with contact distances of F1···π = 2.906
Å and F2···π = 2.791 Å. This distance is significantly shorter
than the separations of this BF4− and palladium centers
(Pd1···Pd2 and Pd3···Pd4), which indicates that the interaction
of BF4− and the phen rings has a major effect in the trapping of
BF4−. This result may be attributed to coordinated PdII atoms,
which withdraw electron density from the phen rings and
increase the affinity of the phen rings for the BF4− anion.16,17
Another BF4− is located at the side of the complex with C−
H···F hydrogen-bonding interactions. As shown in the packing
diagram (Figure 4), molecules of complex 1·8BF4− pack
through weak intermolecular π−π-stacking interactions be-
tween the phen rings of neighboring molecules with a
approximate contact distance of 3.881 Å. Anions are included
in the crystal lattice by C−F···π interactions between C−F and
the aromatic rings and by C−H···F hydrogen bonds between
BF4− and the aromatic protons (Table S2 in the Supporting
Information).
Self-Assembly and Characterization of the Folding
[M4L2]4+ Metallomacrocycle. When ligand H2L1 was treated
with [(dmbpy)2Pd2(NO3)2](NO3)2] in the same ratio as 1 in a
H2O and acetone solution, a low-symmetrical 1H NMR
spectrum was presented (see Figure S8 in the Supporting
Information). However, we obtained [M4L2]4+ instead of
[M8L4]8+ metallomacrocycle, which was supported by ESI-MS
studies, as shown in Figure S18 in the Supporting Information.
The multiply charged molecular ions of 2·4BF4− at m/z 1115.61
and 713.74 are ascribed to [2·2BF4−]2+ and [2·BF4−]3+,
respectively. Compared to the rigid (phen)PdII clip, the
(dmbpy)PdII clip is more flexible to adjusting its configuration
in solution, leading to the formation of 2·4BF4− with a small
cavity of the [M4L2]4+ structure. On the basis of the above
studies and the crystal structure of 1, this folding configuration
was optimized with the CAChe6.1.1 program (Scheme 2).
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Figure 4. Packing diagram of 1·8BF4−.
Self-Assembly and Characterization of the Square-
Type [M4L2]4+ Metallomacrocycles. As shown in Scheme 3,
the fluorescent dipyrazole-bridged metallomacrocycles
3·4NO3−−8·4NO3− are self-assembled in aqueous solution.
[(dmbpy)2Pd2(NO3)2](NO3)2, [(phen)2Pd2(NO3)2](NO3)2,
or [(15-crown-5-phen)2Pd2(NO3)2](NO3)2 were treated with
a suspension containing 1 equiv of H2L2, H2L3, or H2L4
(Scheme 4) in H2O (1 mL) and acetone (0.5 mL) at room
temperature. After stirring for 2 h, the mixture was heated at 60
°C for another 24 h. The resulting light-yellow solution was
then filtered, and the clear filtrate was concentrated, leading to
ions of 4·4BF4− observed at m/z 661.45 and 474.39 (Figure S20
in the Supporting Information) corresponded to the cations
[4·BF4−]3+ and [4]4+, and the multiply charged molecular ions
of 7·4PF6− observed at m/z 1080.91 and 774.69 (Figure S22 in
the Supporting Information) are assignable to cations
[7·PF6−]3+ and [7]4+, respectively.
By the vapor diffusion of diethyl ether into its acetonitrile
solution, complex 3·4BF4− crystallizes in the orthorhombic
space group Pbcn. The complex displays a square-shape hybrid
metallomacrocyclic structure with two pyrazole ligands doubly
bridged by [(phen)PdII]2 corners (Figure 7). Within each
corner, an “open clip” disposition is exhibited with a large
dihedral angle (70.3°) between the two (phen)PdII planes. The
Pd1···Pd2 separation of 3.188 Å indicates typical Pd···Pd
interactions (2.60−3.30 Å).15 The dihedral angle between the
two pyrazole (N5−N6 and N8−N9) planes at the corner is
84.8°, which is smaller than the angles of N1−Pd1−N5 (94.0°),
N2−Pd1−N8A (94.7°), N3−Pd2−N6 (94.2°), and N4−Pd2−
N9A (91.4°). The most interesting feature of the structure is
the binding of two BF4− into the cliplike cavity formed by the
(phen)Pd1 and (phen)Pd2 planes with contact distances of
F1···π = 3.226 Å and F2···π = 3.168 Å. The anion−π
interactions of BF4− and the phen rings have a major effect on
the binding of BF4−. Another BF4− is located at the side of the
complex also by anion−π interaction. In the crystal, molecules
of complex 3·4BF4− pack by weak intermolecular π−π-stacking
interactions involving phen and carbazole rings between
neighboring molecules with an approximate contact distance
of 3.50 Å.
the formation of positively charged [M4L2 ]4+ [M = (phen)PdII,
2
3; M = (dmbpy)PdII, 4], [M4L3 ]4+ [M = (phen)PdII, 5; M =
2
(dmbpy)PdII, 6], or [M4L4 ]4+ [M = (15-crown-5-phen)PdII, 7;
2
M = (dmbpy)PdII, 8] metallomacrocycles with spontaneous
deprotonation of the dipyrazole ligands. Their BF4− or PF6−
salts were prepared by anion exchange with an excess of KBF4
or KPF6.
1
As shown in the H NMR spectrum of 5·4BF4− (Figure 5),
signals exhibited at 8.85−8.87, 8.64−8.65, 8.20, and 8.02−7.99
ppm correspond to a, c, d, and b protons of the phen,
respectively. Other signals belong to ligand L3. The
corresponding resonances of the methylene and methyl groups
of the ligand L3 appear in the upfield region, which reveals one
1
singlet each at 5.73 and 2.68 ppm, respectively. H NMR
analyses of this product indicate the formation of a single
species, and integration of the signals is indicative of a 2:1 ratio
of the metal complex (phen)PdII fragment to the dipyrazole
ligand.
The formation of [M4L2]4+ metallomacrocyclic structures
was further supported by ESI-MS measurement, allowing
assignment of the [(phen)Pd]4L2 , [(dmbpy)Pd]4L2 , [(phen)-
Luminescent Properties and Interaction toward
Anions. As shown in Figure 8, in dimethyl sulfoxide
(DMSO)/H2O (3:1, v/v), H2L1 exhibits characteristic
carbazole emission and fluorescence maxima at 378 and 398
nm and UV−vis spectral peaks at 258 and 298 nm, respectively.
When [(phen)2Pd2(NO3)2](NO3)2 was added in H2L1, the
emission intensity of H2L1 in fluorescent spectra was quenched
sharply because of coordination between N atoms of pyrazole
2
2
Pd]4L3 , [(dmbpy)Pd]4L3 , [(15-crown-5-phen)Pd]4L4 , and
2
2
2
[(dmbpy)Pd]4L4 compositions, respectively. As shown in
2
Figure 6, the multiply charged molecular ions of 5·4BF4− were
observed at m/z 1103.67 ([5·2BF4−]2+), 706.44 ([5·BF4−]3+),
and 508.33 ([5]4+). Similarly, the multiply charged molecular
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Scheme 2. Self-Assembly and Optimized Configuration of [M4L2]4+ Metallomacrocycle−2·4NO3− Optimized with the
a
CAChe6.1.1 Program (See Ref 18)
a
(a) Ball-and-stick model and (b) space-and-stack model. (yellow, Pd; gray, C; white, H; green, F; blue, N).
and Pd atoms and distortion effects on the emission quantum
yield (Φem) of the carbazole rings, while the absorption
intensity of L1 in UV−vis spectra increased notably. A similar
phenomenon was also observed in the emission and absorbance
of H2L2, H2L3, and H2L4 ligands (Figures S24−S26 in the
Supporting Information).
were observed. However, we noticed fluorescence enhance-
ment upon the addition of SCN− (1000 equiv) to 1·8PF6−
(Figure 9), while no change was observed upon application to
three other metallomacrocycles (Figures S27−S29 in the
Supporting Information). Fluorescence titration experiments
were carried out as well; nevertheless, no intensity enhance-
ment was observed until the addition of 100 equiv of SCN−, as
The effects of anions (K+ salts) on the fluorescent emission
intensity of metallomacrocycles 1·8PF6−, 4·4BF4−, 5·4BF4−, and
8·4PF6− (1.5 × 10−6 M) were investigated in a DMSO/H2O
(3:1, v/v) solution at room temperature. Upon the addition of
1000 equiv of BF4−, Br−, Cl−, F−, H2PO4−, I−, N3−, NO3−, and
1
shown in Figure S31 in the Supporting Information. H NMR
experiments of the 1·8PF6− complex were carried out before
and after the addition of 1000 equiv of SCN− in a DMSO-d6/
D2O (3:1, v/v) solution (Figure S32 in the Supporting
Information); we noticed that the number of peaks decreased
2−
SO4 anions, no remarkable fluorescence intensity changes
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Scheme 3. Self-Assembly of Square-Type Hybrid [M4L2]4+ Metallomacrocycles
Scheme 4. Synthesis of Fluorescent Dipyrazole Ligands H2L2, H2L3, and H2L4
1
Figure 5. H NMR spectrum of 5·4BF4− in CD3CN, 25 °C, Si(CH3)4 (1−8, blue, signals of L3; a−d, red, signals of phen).
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Figure 6. (a) ESI-MS spectrum of 5·4BF4− in acetonitrile. (b) Isotopic distribution of the species [5·2BF4−]2+, [5·BF4−]3+, and [5]4+.
dipalladium clips. As a result, quenching caused by metal−
organic complexes was inhibited, resulting in the revival of
fluorescence.
CONCLUSIONS
■
A series of metallomacrocycles with good water solubility can
be obtained in nearly quantitative yield based on fluorescent
carbazole−dipyrazole ligands and dipalladium clips via a
directed self-assembly process. The assemblies have been
1
characterized by elemental analysis, H NMR, and ESI-MS
and in the cases of 1 and 3 by a single-crystal X-ray diffraction
method. These characterizations show that novel [M8L4]8+ and
[M4L2]4+ metallomacrocycles with different size and shape can
be obtained by fine-tuning of the carbazole ligands and
dipalladium corners. The single-crystal structures present that
the dipalladium clips of these metallomacrocycles can interact
with BF4− anions. In addition, the UV−vis absorption and
fluorescence emission intensity of ligands and metallomacro-
cycles and interaction toward anions have been investigated as
well, which show that complex 1·8PF6− selectively interacts
with SCN− anions in aqueous solution.
EXPERIMENTAL SECTION
■
Materials. Potassium hexafluorophosphate (99%) and sodium
tetrafluoroborate (99%) were purchased from Acros Organics and
used without further purification. All other chemicals and solvents
were of reagent grade and were purified according to conventional
methods.19 The dimetal clips [(dmbpy)2Pd2(NO3)2](NO3)2,15,16
[(phen)2Pd2(NO3)2](NO3)2,20 and [(15-crown-5-phen)2Pd2(NO3)2]-
Figure 7. ORTEP diagrams of the molecular structure of 3·4BF4−: (a)
top view; (b) side view. Thermal ellipsoids are shown at the 30%
probability level.
and the ratio of the L1 ligand and phen ring of dipalladium clips
turned to 1:1 from 1:2. On the basis of the above research, we
proposed that, because of the competitive coordination ability
of SCN− and carbazole-based dipyrazole as well as the higher
tension of the 1·8PF6− folding structure, the coordination site
of the 1·8PF6− metallomacrocycle was more likely to be
weakened by SCN−, finally leading to partial decomposition of
21
(NO3)2 (where dmbpy = 4,4′-dimethyl-2,2′-bipyridine and phen =
1,10-phenanthroline) were prepared according to literature proce-
dures. Compounds 9-methylcarbazole-3,6-dicarbaldehyde,22 9-benzyl-
carbazole-3,6-dicarbaldehyde,22 4,4′-(9-benzylcarbazole-3,6-diyl)-
dibenzaldehyde,23 and 1,1′-(9-methylcarbazole-3,6-diyl)bis(4,4,4-tri-
fluorobutane-1,3-dione)24 were synthesized according to published
methods.
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Figure 8. (a) Fluorescence emission spectra and (b) UV−vis absorption spectra of H2L1 and 1·8PF6− in DMSO/H2O (3:1, v/v). λex = 300 nm.
Table 1. Crystallographic Data for Complexes 1·8BF4− and
3·4BF4−
1·8BF4−
3·4BF4−
formula
fw
C180H108F56N36B8Pd8
4776.70
C94H74N18B4F16Pd4
2228.55
orthorhombic
Pbcn
cryst syst
space group
temp (K)
a [Å]
triclinic
P1
̅
153(2)
291(2)
18.2309(2)
18.4937(1)
21.379(2)
72.034(2)
83.197(2)
67.743(3)
6345.7(1)
1
21.622(2)
30.812(3)
22.008(2)
90.00
b [Å]
c [Å]
α [deg]
β [deg]
γ [deg]
V [Å3]
Z
90.00
90.00
Figure 9. Fluorescent intensity of 1·8PF6− at 398 nm upon the
14662(2)
4
2−
addition of excessive BF4−, Br−, Cl−, F−, H2PO4−, I−, N3−, NO3−, SO4
,
and SCN− anions in DMSO/H2O (3:1, v/v; 1.5 × 10−6 M). λex = 300
ρcalcd [g cm−3]
1.250
1.010
nm.
−1
μ [mm ]
0.641
0.539
F(000)
2352
4448
1
Instrumentation. H and 13C NMR experiments were performed
2θmax [deg]
no. of unique data
no. of param
52.00
52.00
on a Bruker Avance DMX400 spectrometer using tetramethylsilane
[Si(CH3)4] as an internal standard. A visual molecular model was
computed using the CAChe6.1.1 program18 to evaluate the shape of
macrocycle 2. ESI-MS measurements were performed with an
HP5989B mass spectrometer. Elemental analysis was performed on
a Thermoquest Flash EA 1112 instrument. UV−visible absorption
spectra were obtained on a Cary 50 Probe UV−visible spectropho-
tometer. Fluorescence spectra were measured using a PerkinElmer
Instruments luminescence spectrophotometer. Fluorescent titrations
were carried out by adding aliquots of various anions as their K+ salts
to 1·8PF6− (1.5 × 10−6 M) in DMSO/H2O (3:1, v/v) at 25 °C.
Excitation was at 300 nm. Both excitation and emission slit widths
were 3 nm.
X-ray Structural Determinations. All single-crystal X-ray
diffraction data were collected on a Bruker Smart Apex CCD area
detector equipped with graphite-monochromated Mo Kα radiation (λ
= 0.710 73 Å). Multiscan absorption correction for all complexes was
performed using the SADABS program.25 All structures were solved by
direct methods, refined employing full-matrix least squares on F2 by
using the SHELXTL (Bruker, 2000) program, and expanded using
Fourier techniques.26 The locations of the Pd atoms were determined,
and all non-H atoms of these complexes were refined anisotropically.
H atoms were included in idealized positions and refined with fixed
geometry with respect to their carrier atoms. Refinement data were
processed by using the SQUEEZE program. All of the crystal data and
structure refinement details, such as the unit cell, space group, data
collection, and refinement parameters, are presented in Table 1.
Synthesis. Synthesis of Organic Ligands. General Procedure
for Acetylacetone..27 A 5 mL CH2Cl2 solution of dialdehyde (8.4
mmol), biacetyl, and trimethyl phosphite adduct (11 mL) was stirred
24 805
14 421
1299
618
a
GOF [F2]
1.02
1.07
b
R1 [F2 > 2σ(F2)], wR2 [F2]
0.0547, 0.1177
0.0535, 0.1325
Δρmin, Δρmax [e Å−3]
−0.71, 0.99
−0.33, 0.47
a
GOF = [w(Fo2 − Fc2)2]/(n − p)1/2, where n and p denote the number
b
of data points and the number of parameters, respectively. R1 = (||Fo|
− |Fc||)/|Fo|; wR2 = [w(Fo − Fc2)2]/[w(Fo )2]1/2, where w = 1/
2
2
[σ2(Fo ) + (aP)2 + bP] and P = (Fo + 2Fc2)/3.
2
2
at room temperature under N2 conditions. After the solution became
clear, the solvent was removed and the resulting oil product was
suspended in 30 mL of methanol under reflux. After 24 h, solvent was
distilled; purification was achieved by column chromatography to
afford pure product as a white or light-yellow powder.
General Pyrazole Preparation..27 Hydrazine hydrate (2 mL, 80%)
was added during a 10 min period to a stirred and refluxed solution of
acetylacetone (8.4 mmol) in 20 mL of ethanol. After 12 h, the solvent
was concentrated and filtered, and the resulting solid was washed twice
with H2O and vacuum-dried.
3,3′-(9-Methyl-9H-carbazole-3,6-diyl)bis(4-hydroxypent-3-en-2-
one) (a). The above general acetylacetone preparation procedure was
followed with 9-methylcarbazole-3,6-dicarbaldehyde (2.0 g, 8.4 mmol)
to give a as a white powder. The product was vacuum-dried (634 mg,
1
20%). H NMR (400 MHz, CDCl3, 25 °C, Si(CH3)4, ppm): δ 16.73
(s, 2H, −OH), 7.87 (s, 2H, Cz−H), 7.46−7.44 (d, J = 8.3 Hz, 2H,
Cz−H), 7.31−7.28 (d, 2H, Cz−H), 3.93 (s, 3H, N−CH3), 1.93 (s,
12H, −CH3). 13C NMR (100 MHz, CDCl3, 25 °C, Si(CH3)4, ppm): δ
2450
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Inorganic Chemistry
Article
191.4, 140.6, 129.1, 127.8, 122.8, 115.5, 109.0, 29.3, 24.4. Elem anal.
Calcd for C23H23NO4: C, 73.19; H, 6.14; N, 3.71. Found: C, 73.17; H,
6.09; N, 3.69. ESI-MS anal. Calcd for [C23H23NO4 + Na]+: m/z
400.1519. Found: m/z 400.1521.
H), 7.86−7.80 (m, 6H, Cz−H and Cz−Ar−H), 7.75−7.73 (d, J = 8.5
Hz, 2H, Cz−H), 7.43−7.40 (d, J = 8.2 Hz, 4H, Ar−H), 7.33−7.24 (m,
5H, Ar−H), 5.74 (s, 2H, −CH2), 2.27 (s, 12H, −CH3). 13C NMR
(100 MHz, DMSO-d6, 25 °C, Si(CH3)4, ppm): δ 141.0, 140.6, 138.9,
138.2, 132.6, 131.9, 129.6, 129.1, 127.8, 127.2, 125.4, 123.7, 119.2,
117.1, 110.5, 46.3, 12.0. Elem anal. Calcd for C41H35N5·H2O: C, 79.97;
H, 6.06; N, 11.37. Found: C, 79.94; H, 6.08; N, 11.36. ESI-MS anal.
Calcd for [C41H35N5 + H]+: m/z 598.2965. Found: m/z 598.2922.
[(phen)8Pd8L14](NO3)8 (1·8NO3−), [(phen)8Pd8L14](PF6)8
3,3′-(9-Benzyl-9H-carbazole-3,6-diyl)bis(4-hydroxypent-3-en-2-
one) (b). The above general acetylacetone preparation procedure was
followed with 9-benzylcarbazole-3,6-dicarbaldehyde (2.63 g, 8.4
mmol) to give b as a light-yellow powder. The product was
1
vacuum-dried (762 mg, 20%). H NMR (400 MHz, CDCl3, 25 °C,
(1·8PF6−), and [(phen)8Pd8L1 ](BF4)8 (1·8BF4−)
Si(CH3)4, ppm): δ 16.75 (s, 2H, −OH), 7.92−7.91 (d, J = 1.4 Hz, 2H,
Cz−H), 7.45−7.42 (d, J = 8.3 Hz, 2H, Cz−H), 7.36−7.31 (m, 3H,
Ar−H), 7.28−7.27 (d, J = 1.7, 2H, Cz−H), 7.25 (m, 2H, Ar−H), 5.57
(s, 2H, −CH2), 1.96 (s, 12H, −CH3). 13C NMR (100 MHz, CDCl3,
25 °C, Si(CH3)4, ppm): δ 191.3, 140.8, 139.6, 138.4, 128.6, 128.1,
127.6, 126.4, 125.7, 118.3, 109.4, 46.9, 24.2. Elem anal. Calcd for
C29H27NO4: C, 76.80; H, 6.00; N, 3.09. Found: C, 76.82; H, 6.09; N,
3.03. ESI-MS anal. Calcd for [C29H27NO4 + Na]+: m/z: 476.1832.
Found: m/z 476.1803.
3,3′-[(9-Benzyl-9H-carbazole-3,6-diyl)bis(4,1-phenylene)]bis(4-
hydroxypent-3-en-2-one) (c). The above general acetylacetone
preparation procedure was followed with 4,4′-(9-benzylcarbazole-3,6-
diyl)dibenzaldehyde (4.0 g, 8.4 mmol) to give c as a light-yellow
powder. The product was vacuum-dried (1.02 g, 20%). 1H NMR (400
MHz, CDCl3, 25 °C, Si(CH3)4, ppm): δ 16.74 (s, 2H, −OH), 8.47−
8.45 (s, 2H, Cz−H), 7.77−7.75 (d, J = 8.3 Hz, 4H, Cz−Ar−H), 7.77−
7.75 (covered, 2H, Cz−H), 7.50−7.48 (d, J = 8.2 Hz, 2H, Cz−H),
7.32−7.21 (m, 9H, Cz−Ar−H and Ar−H), 5.61 (s, 2H, −CH2), 1.99
(s, 12H, −CH3). 13C NMR (100 MHz, CDCl3, 25 °C, Si(CH3)4,
ppm): δ 191.1, 141.0, 140.8, 136.9, 135.1, 132.3, 131.6, 128.9, 127.7,
127.6, 126.5, 125.5, 123.8, 118.9, 114.9, 109.5, 46.9, 24.3. Elem anal.
Calcd for C41H35NO4: C, 81.30; H, 5.82; N, 2.31. Found: C, 81.27; H,
5.85; N, 2.32. ESI-MS anal. Calcd for [C41H35NO4 + Na]+: m/z
628.2488. Found: m/z 628.2403.
9-Methyl-3,6-bis[3-(trifluoromethyl)-1H-pyrazol-5-yl]-9H-carba-
zole (H2L1). The above general pyrazole preparation procedure was
followed with 1,1′-(9-methylcarbazole-3,6-diyl)bis(4,4,4-trifluorobu-
tane-1,3-dione) (755 mg, 1.68 mmol), and a white solid of H2L1
was obtained (717 mg, 95%). 1H NMR (400 MHz, DMSO-d6, 25 °C,
Si(CH3)4, ppm): δ 14.06 (s, 2H, −NH), 8.66 (s, 2H, Cz−H), 7.99−
7.97 (d, J = 8.8 Hz, 2H, Cz−H), 7.79−7.77 (d, J = 8.6 Hz, 2H, Cz−
H), 7.18 (s, 2H, −CH), 3.97 (s, 3H, N−CH3).
3,6-Bis(3,5-dimethyl-1H-pyrazol-4-yl)-9-methyl-9H-carbazole
(H2L2). The above general pyrazole preparation procedure was
followed with a (634 mg, 1.68 mmol), and a white solid of H2L2
was obtained (590 mg, 95%). 1H NMR (400 MHz, DMSO-d6, 25 °C,
Si(CH3)4, ppm): δ 12.23 (s, 2H, −NH), 8.08 (d, J = 1.3 Hz, 2H, Cz-
H), 7.62−7.60 (d, J = 8.3 Hz, 2H, Cz−H), 7.38−7.35 (d, J1 = 8.4 Hz,
J2 = 3.2 Hz, 2H, Cz−H), 3.91 (s, 3H, N−CH3), 2.23 (s, 12H, −CH3).
13C NMR (100 MHz, DMSO-d6, 25 °C, Si(CH3)4, ppm): δ 139.9,
4
Self-Assembly of MetallomacrocyclesGeneral Procedures
[(phen)2Pd2(NO3)2](NO3)2 (18.3 mg, 0.02 mmol) was added to a
suspension of H2L1 (10 mg, 0.02 mmol) in a H2O (1 mL) and acetone
(0.5 mL) solution. The mixture was stirred for 2 h at room
temperature and was then heated at 60 °C for another 24 h to react
fully. After that, the resulting solution was filtered, and the clear yellow
filtrate was evaporated to dryness to give a yellow solid of 1·8NO3−.
Yield: 19 mg (67%). The PF6− salt of 1 (1·8PF6−) was prepared by
anion exchange of 1·8NO3− with a 10-fold excess of KPF6 in a
methanol solution in quantitative yield. 1H NMR (400 MHz, CD3CN,
25 °C, Si(CH3)4, ppm): δ 9.11 (s, 4H), 8.84−8.82 (d, J = 7.9 Hz, 4H),
8.79−8.77 (d, J = 8.0 Hz, 4H), 8.68−8.66 (d, J = 8.2 Hz, 4H), 8.65−
8.64 (d, J = 5.4 Hz, 4H), 8.57−8.55 (d, J = 5.0 Hz, 4H), 8.40−8.38 (d,
J = 8.2 Hz, 4H), 8.24−8.22 (d, J = 5.3 Hz, 4H), 8.15−8.12 (dd, J1 = 8.3
Hz, J2 = 1.5 Hz, 4H), 8.14 (s, 8H), 7.93−7.90 (d, J = 8.8 Hz, 4H),
7.91−7.88 (dd, J1 = 8.2 Hz, J2 = 5.5 Hz, 4H), 7.85−7.83 (d, J = 5.7 Hz,
4H), 7.83−7.81 (d, J = 7.9 Hz, 4H), 7.82−7.79 (d, J = 8.7 Hz, 4H),
7.76 (s, 4H), 7.76−7.72 (dd, J1 = 8.2 Hz, J2 = 5.5 Hz, 4H), 7.69−7.68
(d, J = 5.2 Hz, 4H), 7.63−7.61 (d, J = 8.5 Hz, 4H), 7.35−7.32 (dd, J1 =
8.3 Hz, J2 = 5.5 Hz, 4H), 7.25 (s, 4H), 6.95 (s, 4H), 6.67−6.65 (d, J =
8.5 Hz, 4H), 3.68 (s, 12H). ESI-MS (acetonitrile): m/z 1602.33
([1·5PF6−]3+). Elem anal. Calcd for C180H108N36Pd8P8F72·2H2O: C,
40.96; H, 2.14; N, 9.55. Found: C, 40.86; H, 2.34; N, 9.43. The BF4−
salt of 1 (1·8BF4−) was also obtained as yellow microcrystals in
quantitative yield. X-ray-quality crystals were grown by the slow vapor
diffusion of diethyl ether into a solution of 1·8BF4− in acetonitrile at
room temperature.[(dmbpy)4Pd4L1 ](NO3)4 (2·4NO3−) and
2
[(dmbpy)4Pd4L1 ] (BF4)4 (2·4BF4−)
2
The same procedure as that employed for 1·8NO3− was used to make
2·4NO3−, except that [(dmbpy)2Pd2(NO3)2](NO3)2 (18.5 mg, 0.02
mmol) was used as the starting material. Yield: 21.4 mg (75%). The
BF4− salt of 2 (2·4BF4−) was prepared by anion exchange of 2·4NO3−
with a 10-fold excess of KBF4 in a methanol solution in quantitative
yield. 1H NMR (400 MHz, CD3CN, 25 °C, Si(CH3)4, ppm): δ 8.92 (s,
2H), 8.25 (s, 2H), 8.20 (s, 2H), 8.15−8.14 (d, J = 5.9 Hz, 2H), 8.12−
8.10 (d, J = 5.9 Hz, 2H), 8.03−8.00 (dd, J1 = 8.5 Hz, J2 = 1.7 Hz, 2H),
7.90 (s, 2H), 7.72 (s, 2H), 7.67 (s, 2H), 7.60−7.58 (d, J = 5.9 Hz, 2H),
7.57 (s, 2H), 7.54−7.52 (d, J = 8.5 Hz, 2H), 7.46−7.44 (d, J = 6.2 Hz,
2H), 7.35−7.33 (t, J = 4.7 Hz, 4H), 7.16−7.14 (d, J = 5.9 Hz, 2H),
6.90 (s, 2H), 6.84 (s, 2H), 6.82−6.80 (d, J = 8.6 Hz, 2H), 6.79−6.77
(d, J = 6.5 Hz, 2H), 3.76 (s, 6H), 2.59 (s, 8H), 2.56 (s, 8H), 2.42 (s,
8H). ESI-MS (acetonitrile): m/z 1115.61 ([2·2BF4−]2+) and 713.74
([2·BF4−]3+). Elem anal. Calcd for C90H70N18Pd4B4F28·H2O: C, 44.62;
H, 3.00; N, 10.41. Found: C, 44.46; H, 2.84; N, 10.33.
[(phen)4Pd4L2 ](NO3)4 (3·4NO3−) and [(phen)4Pd4L2 ](BF4)4
127.6, 125.0, 122.8, 121.1, 118.4, 109.4, 56.5, 29.5, 19.0, 11.9. Elem
anal. Calcd for C23H23N5·H2O: C, 71.29; H, 6.50; N, 18.07. Found: C,
71.37; H, 6.59; N, 18.01. ESI-MS anal. Calcd for [C23H23N5 + H]+: m/
z 370.2026. Found: m/z 370.2037.
9-Benzyl-3,6-bis(3,5-dimethyl-1H-pyrazol-4-yl)-9H-carbazole
(H2L3). The above general pyrazole preparation procedure was
followed with b (762 mg, 1.68 mmol), and a white solid of H2L3
was obtained (711 mg, 95%). 1H NMR (400 MHz, DMSO-d6, 25 °C,
Si(CH3)4, ppm): δ 12.23 (s, 2H, −NH), 8.11 (d, J = 1.2 Hz, 2H, Cz−
H), 7.66−7.63 (d, J = 8.5 Hz, 2H, Cz−H), 7.24−7.35 (m, 7H, Cz−H
and Ar−H), 5.67 (s, 2H, N−CH2), 2.09 (s, 12H, −CH3). 13C NMR
(100 MHz, DMSO-d6, 25 °C, Si(CH3)4, ppm): δ 140.8, 139.4, 138.4,
129.1, 127.8, 127.6, 127.4, 125.3, 123.0, 121.2, 118.2, 109.8, 46.3, 11.9.
Elem anal. Calcd for C29H27N5·2H2O: C, 72.33; H, 6.49; N, 14.54.
Found: C, 72.31; H, 6.49; N, 14.51. ESI-MS anal. Calcd for [C29H27N5
+ H]+: m/z: 446.2339. Found: m/z 446.2315.
2
2
(3·4BF4−)
The same procedure as that employed for 1·8NO3− was used to make
3·4NO3−, except that [(phen)2Pd2(NO3)2](NO3)2 (33.6 mg, 0.04
mmol) and H2L2 (15 mg, 0.04 mmol) were used as starting materials.
Yield: 37.7 mg (80%). The BF4− salt of 3 (3·4BF4−) was prepared by
exchange with a 10-fold excess of KBF4 in a methanol solution in
quantitative yield. Pure 3·4BF4−, as a microcrystalline light-yellow
solid, was obtained by the vapor diffusion of diethyl ether into a
solution of 3·4BF4− in acetonitrile at room temperature. Yield: 20 mg
(53%). 1H NMR (400 MHz, CD3CN, 25 °C, Si(CH3)4, ppm): δ
9.08−9.06 (d, J = 8.2 Hz, 8H, phen−H), 8.70−8.69 (d, J = 4.9 Hz, 8H,
phen−H), 8.35 (s, 8H, phen−H), 8.19−8.15 (dd, J1 = 8.2 and 5.3 Hz,
8H, phen−H), 8.15 (s, 4H, Cz-H), 7.75−7.73 (d, J = 8.7 Hz, 4H, Cz−
H), 7.68−7.65 (d, J = 8.6 Hz, 4H, Cz−H), 3.98 (s, 6H, N−CH3), 2.60
(s, 24H, L2−CH3). ESI-MS (acetonitrile): m/z 1027.63 ([3·2BF4−]2+).
9-Benzyl-3,6-bis[4-(3,5-dimethyl-1H-pyrazol-4-yl)phenyl]-9H-car-
bazole (H2L4). The above general pyrazole preparation procedure was
followed with c (1.02 g, 1.68 mmol), and a white solid of H2L4 was
1
obtained (954 mg, 95%). H NMR (400 MHz, DMSO-d6, 25 °C,
Si(CH3)4, ppm): δ 12.35 (s, 2H, −NH), 8.80 (d, J = 0.8 Hz, 2H, Cz−
2451
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Inorganic Chemistry
Article
Elem anal. Calcd for C94H74N18Pd4B4F16·H2O: C, 50.25; H, 3.41; N,
11.22. Found: C, 50.09; H, 3.34; N, 11.06. X-ray-quality crystals were
grown by the slow vapor diffusion of diethyl ether into a solution of
Calcd for C106H98N18Pd4B4F16·2H2O: C, 52.33; H, 4.23; N, 10.36.
Found: C, 52.25; H, 4.52; N, 10.27.[(15-crown-5-phen)4Pd4L4 ]-
2
(NO3)4 (7·4NO3−) and [(15-crown-5-phen)4Pd4L4 ](PF6)4 (7·4PF6−)
2
3·4BF4− in acetonitrile at room temperature.[(dmbpy)4Pd4L2 ](NO3)4
The same procedure as that employed for 1·8NO3− was used, except
that H2L4 (10 mg, 0.02 mmol) and [(15-crown-5-phen)2Pd2(NO3)2]-
(NO3)2 (20.0 mg, 0.02 mmol) were used as starting materials to give a
yellow solid of 7·4NO3−. Yield: 22.5 mg (75%). The PF6− salt of 7
(7·4PF6−) was obtained as yellow microcrystals in quantitative yield.
1H NMR (400 MHz, CD3CN, 25 °C, Si(CH3)4, ppm): δ 8.98−8.96
(d, J = 8.6 Hz, 8H, phen−H), 8.62 (s, 4H, Cz−H), 8.49−8.48 (d, J =
5.3 Hz, 8H, phen−H), 7.98−7.95 (d, J = 8.4 Hz, 8H, phen−H), 7.96−
7.94 (d, J = 8.3 Hz, 8H, Cz−Ar−H), 7.91−7.89 (dd, J1 = 8.7 Hz, J2 =
1.4 Hz, 4H, Cz−H), 7.71−7.69 (d, J = 8.4 Hz, 4H, Cz−H), 7.65−7.63
(d, J = 8.2 Hz, 8H, Cz−Ar−H), 7.39−7.27 (m, 10H, Ar−H), 5.74 (s,
4H, Ar−CH2), 3.73−3.66 (m, 64H, crown−H), 2.65 (s, 24H, L4−
CH3). ESI-MS (acetonitrile): m/z 1080.91 ([7·PF6−]3+) and 774.69
([7]4+). Elem anal. Calcd for C162H154F24P4N18Pd4O20·3H2O: C,
52.13; H, 4.32; N, 6.75. Found: C, 52.06; H, 4.37; N, 6.84.
[(dmbpy)4Pd4L4 ](NO3)4 (8·4NO3−) and [(dmbpy)4Pd4L4 ](BF4)4
2
(4·4NO3−) and [(dmbpy)4Pd4L2 ](BF4)4 (4·4BF4−)
2
The same procedure as that employed for 1·8NO3− was used to make
4·4NO3−, except that [(dmbpy)2Pd2(NO3)2](NO3)2 (33.8 mg, 0.04
mmol) and H2L2 (15 mg, 0.04 mmol) were used as starting materials.
Yield: 37.7 mg (80%). 1H NMR (400 MHz, CD3OD, 25 °C,
Si(CH3)4, ppm): δ 8.46 (s, 8H, dmbpy−H), 8.21−8.19 (d, J = 5.8 Hz,
8H, dmbpy−H), 8.15 (s, 4H, Cz−H), 7.63−7.62 (d, J = 5.6 Hz, 8H,
dmbpy−H), 7.62−7.60 (d, J = 8.5 Hz, 4H, Cz−H), 7.56−7.54 (dd, J1
= 8.4 Hz, J2 = 1.3 Hz, 4H, Cz−H), 3.96 (s, 6H, N−CH3), 2.64 (s,
24H, L2−CH3), 2.56 (s, 24H, dmbpy−CH3). Elem anal. Calcd for
C94H90N22Pd4O12·H2O: C, 52.18; H, 4.29; N, 14.24. Found: C, 52.09;
H, 4.34; N, 14.06.
The BF4− salt of 4 (4·4BF4−) was obtained as yellow microcrystals in
quantitative yield after anion exchange. 1H NMR (400 MHz, CD3CN,
25 °C, Si(CH3)4, ppm): δ 8.26 (s, 8H, dmbpy−H), 8.14−8.13 (d, J =
1.0 Hz, 4H, Cz−H), 8.12−8.10 (d, J = 5.7 Hz, 8H, dmbpy−H), 7.67−
7.64 (d, J = 8.5 Hz, 4H, Cz−H), 7.60−7.58 (dd, J1 = 8.4 Hz, J2 = 1.6
Hz, 4H, Cz−H), 7.53−7.52 (d, J = 5.1 Hz, 8H, dmbpy−H), 3.96 (s,
6H, N−CH3), 2.60 (s, 24H, L2−CH3), 2.55 (s, 24H, dmbpy−CH3).
ESI-MS (acetonitrile): m/z 661.45 ([4·BF4−]3+) and 474.39 ([4]4+).
Elem anal. Calcd for C94H90N18Pt4B4F16·H2O: C, 49.90; H, 4.10; N,
2
2
(8·4BF4−)
The same procedure as that employed for 1·8NO3− was used, except
that H2L4 (10 mg, 0.02 mmol) and [(dmbpy)2Pd2(NO3)2](NO3)2
(13.9 mg, 0.02 mmol) were used as starting materials to give a yellow
solid 8·4NO3−. Yield: 13.2 mg (55%). The BF4− salt of 8 (8·4BF4−) was
1
obtained as yellow microcrystals in quantitative yield. H NMR (400
11.14. Found: C, 49.76; H, 4.13; N, 11.23.[(phen)4Pd4L3 ](NO3)4
MHz, CD3CN, 25 °C, Si(CH3)4, ppm): δ 8.59 (d, J = 1.4 Hz, 4H, Cz−
H), 8.23 (s, 8H, dmbpy−H), 8.01−8.00 (d, J = 5.9 Hz, 8H, dmbpy−
H), 7.91−7.89 (d, J = 8.2 Hz, 8H, Cz−Ar−H), 7.86−7.84 (dd, J1 = 8.6
Hz, J2 = 1.6 Hz, 4H, Cz−H), 7.67−7.65 (d, J = 8.5 Hz, 4H, Cz−H),
7.56−7.54 (d, J = 8.2 Hz, 8H, Cz−Ar−H), 7.50−7.49 (d, J = 5.2 Hz,
8H, dmbpy−H), 7.36−7.24 (m, 10H, Ar−H), 5.71 (s, 4H, Ar−CH2),
2.59 (s, 24H, L4−CH3), 2.51 (s, 24H, dmbpy−CH3). ESI-MS
(methanol): m/z 587.64 ([8]4+). Elem anal. Calcd for
C130H114F16B4N18Pd4·3H2O: C, 56.67; H, 4.39; N, 9.15. Found: C,
56.76; H, 4.47; N, 9.24.
2
(5·4NO3−) and [(phen)4Pd4L3 ](BF4)4 (5·4BF4−)
2
The same procedure as that employed for 1·8NO3− was used to make
5·4NO3−, except that H2L3 (10 mg, 0.02 mmol) was used as the
starting material. Yield: 21.5 mg (85%). 1H NMR (400 MHz, CD3OD,
25 °C, Si(CH3)4, ppm): δ 9.02−9.00 (d, J = 8.2 Hz, 8H, phen−H),
8.80−8.79 (d, J = 5.0 Hz, 8H, phen−H), 8.33 (s, 4H, Cz−H), 8.30 (s,
8H, phen−H), 8.15−8.12 (dd, J1 = 8.2 Hz, J2 = 5.3 Hz, 8H, phen−H),
7.76−7.74 (d, J = 8.4 Hz, 4H, Cz−H), 7.71−7.69 (d, J = 8.4 Hz, 4H,
Cz−H), 7.41−7.33 (m, 10H, Ar−H), 5.77 (s, 4H, Ar−CH2), 2.73 (s,
24H, L3−CH3). Elem anal. Calcd for C106H82N22O12Pd4·2H2O: C,
54.93; H, 3.74; N, 13.30. Found: C, 54.75; H, 3.81; N, 13.25.
ASSOCIATED CONTENT
■
The BF4− salt of 5 (5·4BF4−) was obtained as yellow microcrystals in
quantitative yield after anion exchange. 1H NMR (400 MHz, CD3CN,
25 °C, Si(CH3)4, ppm): δ 8.88−8.85 (dd, J1 = 8.3 Hz, J2 = 1.0 Hz, 8H,
phen−H), 8.65−8.64 (dd, J1 = 5.3 Hz, J2 = 1.0 Hz, 8H, phen−H), 8.26
(d, J = 1.2 Hz, 4H, Cz−H), 8.20 (s, 8H, phen−H), 8.02−7.99 (dd, J1 =
8.3 Hz, J2 = 5.3 Hz, 8H, phen−H), 7.74−7.72 (d, J = 8.4 Hz, 4H, Cz−
H), 7.68−7.65 (dd, J1 = 8.4 Hz, J2 = 1.5 Hz, 4H, Cz−H), 7.40−7.31
(m, 10H, Ar−H), 5.73 (s, 4H, Ar−CH2), 2.68 (s, 24H, L3−CH3). ESI-
MS (acetonitrile): m/z 1103.67 ([5·2BF4−]2+), 706.44 ([5·BF4−]3+),
and 508.33 ([5]4+). Elem anal. Calcd for C106H82N18Pd4B4F16·2H2O:
C, 52.68; H, 3.59; N, 10.43. Found: C, 52.65; H, 3.61; N, 10.55.
[(dmbpy)4Pd4L3 ](NO3)4 (6·4NO3−) and [(dmbpy)4Pd4L3 ](BF4)4
S
* Supporting Information
1H and 13C NMR spectra of H2L1, H2L2, H2L3, and H2L4, H
1
NMR spectra of 2−8 and ESI-MS spectra of 1−4 and 6−8,
UV−vis and fluorescent spectra, 1H NMR spectrum of 1·8PF6−
interacted with SCN−, crystal packings of complexes 1·8BF4−
and 3·4BF4−, tables of selected bond lengths and angles for
1·8BF4− and 3·4BF4−, and X-ray crystallographic files for
complexes 1·8BF4− and 3·4BF4− in CIF format. This material is
available free of charge via the Internet at http://pubs.acs.org.
2
2
(6·4BF4−)
AUTHOR INFORMATION
■
The same procedure as that employed for 1·8NO3− was used, except
that H2L3 (10 mg, 0.02 mmol) and [(dmbpy)2Pd2(NO3)2](NO3)2
(18.4 mg, 0.02 mmol) were used as starting materials to give a yellow
Corresponding Author
*E-mail: yusy@ruc.edu.cn.
solid 6·4NO3−. Yield: 24.7 mg (87%). H NMR (400 MHz, CD3OD,
1
Notes
25 °C, Si(CH3)4, ppm): δ 8.46 (s, 8H, dmbpy−H), 8.19 (s, 8H,
dmbpy−H), 8.18 (s, 4H, Cz−H), 7.62−7.60 (d, J = 5.7 Hz, 8H,
dmbpy−H), 7.60−7.58 (d, J = 8.8 Hz, 4H, Cz−H), 7.52−7.50 (dd, J1
= 8.4 Hz, J2 = 1.6 Hz, 4H, Cz−H), 7.33−7.24 (m, 10H, Ar−H), 5.68
(s, 4H, Ar−CH2), 2.63 (s, 24H, L3−CH3), 2.56 (s, 24H, dmbpy−
CH3). Elem anal. Calcd for C106H98N22O12Pd4·2H2O: C, 54.55; H,
4.41; N, 13.20. Found: C, 54.75; H, 4.27; N, 13.15.
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
■
This project was supported by the Fundamental Research
Funds for the Central Universities and the Research Funds of
Renmin University of China (Grant 11XNL011), the National
Natural Science Foundation of China (Grants 51073171 and
91127039), and the Beijing Natural Science Foundation (Grant
2112018).
The BF4− salt of 6 (6·4BF4−) was obtained as yellow microcrystals in
quantitative yield after anion exchange. 1H NMR (400 MHz, CD3CN,
25 °C, Si(CH3)4, ppm): δ 8.25 (s, 8H, dmbpy−H), 8.16 (d, J = 1.2 Hz,
4H, Cz−H), 8.10−8.08 (d, J = 5.8 Hz, 8H, dmbpy−H), 7.68−7.66 (d,
J = 8.5 Hz, 4H, Cz−H), 7.56−7.54 (dd, J1 = 8.4 Hz, J2 = 1.6 Hz, 4H,
Cz−H), 7.51−7.50 (d, J = 5.5 Hz, 8H, dmbpy−H), 7.34−7.27 (m,
10H, Ar−H), 5.68 (s, 4H, Ar−CH2), 2.60 (s, 24H, L3−CH3), 2.54 (s,
24H, dmbpy−CH3). ESI-MS (acetonitrile): m/z 1111.67
([6·2BF4−]2+), 712.18 ([6·BF4−]3+), and 512.43 ([6]4+). Elem anal.
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