The
first porous molecular conductor (PMC), which exhibits porosity,
a through-space conduction pathway and rich charge carriers (electrons),
was prepared through electrocrystallization from Cd2+ and N,N′-di(4-pyridyl)-1,4,5,8-naphthalenetetracarboxdiimide
(NDI-py). [Cd(NDI-py)(OH2)4](NO3)1.3±0.1·nDMA (PMC-1) was assembled by π–π stacking among one-dimensional
(1D) linear coordination polymers. The NDI cores were partially reduced
into radical anions to form conductive π-stacked columns, yielding
(1.0–3.3) × 10–3 S cm–1 at room temperature. Moreover, the electrical conductivity was significantly
enhanced by removing the solvent molecules from PMC-1, indicating that PMCs are promising as molecule-responsive conductive
materials.
An L-phenylalanyl chloromethylketone-based inhibitor equipped with a Hoveyda-Grubbs catalyst moiety was regioselectively incorporated into the cleft of α-chymotrypsin through the intrinsic inhibition mechanism of the protein to construct an artificial organometallic protein.
The use of metallo-supramolecular polymer (MSP) as a thin-film-based redox supercapacitor electrode material is reported for the first time. Fe(II)-and Ru(II)-based MSPs (polyFe and polyRu, respectively) were synthesized by complexation of appropriate metal salts with 4′,4″-(1,4-phenylene)bis-2,2′:6′,2″terpyridine, and thin films of these polymers were prepared by spray coating onto an indium tin oxide glass substrate. A study of the energy storage performances of the polyFe and polyRu films in a nonaqueous electrolyte system revealed volumetric capacitances of ∼62.6 ± 3 F/cm 3 for polyFe and 98.5 ± 7 F/cm 3 for polyRu at a current density of 2 A/cm 3 . To improve the energy storage performance over a wider potential range, asymmetric supercapacitor (ASC) displays were fabricated with suitable combinations of the MSPs as cathodic materials and Prussian blue as the anodic counter material in a sandwich configuration with a transparent polymeric ion gel as the electrolyte. The fabricated ASCs showed a maximum volumetric energy density (∼10−18 mW h/cm 3 ) that was higher than that of lithium thin-film batteries and a power density (7 W/cm 3 ) comparable to that of conventional electrolyte capacitors, with superb cyclic stability for 10 000 cycles. To demonstrate the practical use of the MSP, the illumination of a light-emitting diode bulb was powered by a laboratory-made device. This work should inspire the development of highperformance thin-film flexible supercapacitors based on MSPs as active cathodic materials.
Dual-redox metallo-supramolecular polymers with a zigzag structure (polyFe−N and polyRu−N) were successfully synthesized by 1:1 complexation of a redox-active Fe(II) or Ru(II) ion and 4,4-bis(2,2:6,2-terpyridinyl)phenyl-triphenylamine (L TPA ) as a redox-active ligand. The polymers had high solubility in methanol, and the polymer solutions showed dark brown (polyFe−N) or orange-red (polyRu−N) coloration. UV−vis spectra of the polymers displayed a strong metal-to-ligand charge transfer (MLCT) absorption in the visible region. Cyclic voltammograms of the polymer films exhibited two pairs of reversible redox waves. The first redox at ∼0.5 V versus Ag/Ag + was assigned to the redox in the triphenylamine (TPA) moiety of L TPA , and the second redox at 0.8 V versus Ag/Ag + (polyFe−N) or 0.9 V versus Ag/Ag + (polyRu−N) was given to the redox of Fe(II)/(III) or Ru(II)/(III), respectively. Upon applying a positive potential of more than 0.5 V versus Ag/Ag + to the polymer films, a new absorption at ∼820 nm in the near-infrared (NIR) region appeared with wide tailing to the longer wavelength. It is considered that the new absorption in the NIR region is caused by the polaron band of the oxidized ligand in the polymers. When the applied potential was increased to 1.0 V versus Ag/Ag + (polyFe−N) or 1.1 V versus Ag/Ag + (polyRu−N), the maximum wavelength of the new absorption in the NIR region shifted to 885−900 nm and the absorbance was further enhanced with disappearance of the MLCT absorption. Eventually, the original colors of the polymers were faint to light green. This visible-to-NIR electrochromism was reversible, and maximum optical contrast (ΔT) reached 52% in the visible region and 80% in the NIR region. A prototype solid-state device with the polymer was fabricated for practical utilization, exhibiting excellent cycle stability of >4000 cycles with maintaining high optical contrast from the visible-to-NIR range.
The
efficiency of ring-closing metathesis catalyzed by a Hoveyda–Grubbs
type catalyst in water can be enhanced by addition of a chloride salt
under neutral conditions. UV–vis spectroscopic study showed
that a characteristic band of the catalyst around 380 nm remained
over 16 h in the presence of KCl, whereas the band distinctly decreased
in the absence of KCl. The disappearance of the band is ascribed to
a displacement of a chloride ligand by a water molecule or a hydroxide
anion. The spectral changes can be related to the metathesis activity.
The experimental results indicate that avoidance of the chloride ligand
loss is important to maintain the metathesis activity in water.
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