Publications by authors named "Daiki Kuzuhara"

This work reported "trinitarian" porphyrin nanobelts, contained hetero-trimetal ions. The high-resolution mass spectrometry and X-ray crystallography proved PNBNiCuPd consisting of three different bent porphyrin(2.1.

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Aromaticity is one of the most important and widely used concepts in chemistry. Among the various experimentally discovered and theoretically predicted compounds that possess different types of aromaticity, conflicting aromaticity, where aromatic and antiaromatic electron delocalization is present in one molecule simultaneously, remains one of the most controversial and elusive concepts, although theoretically predicted 15 years ago. In this work, we synthesized a novel conflicting aromatic trirhodium complex that contains a σ-aromatic metal fragment surrounded by the π-antiaromatic organic ligand and characterized it by nuclear magnetic resonance spectroscopy, high-resolution mass spectrometry, and X-ray single crystal structure analysis.

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Kekulene, a cycloarene composed of 12 fused benzene rings in a circular arrangement, exhibits a highly planar and robust structure. Kekulene has been the subject of investigation into its aromaticity and electronic structure, particularly in relation to the cyclic benzenoid. We have successfully synthesized novel bowl-shaped kekulene analogues with five-membered rings incorporated into the kekulene structure.

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The molecular structure, electrochemistry, spectroelectrochemistry and electrocatalytic oxygen reduction reaction (ORR) features of two Co porphyrin(2.1.2.

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Novel 24π antiaromatic and 26π aromatic aryl rosarins were successfully obtained for the first time from β-free bipyrrole through a one-pot synthesis. Because of the absence of substituents at the β-positions of the pyrrole units, the β-free pristine rosarin backbones were highly planar, as confirmed using X-ray crystallography. Optical measurements indicated interconversion between 24π antiaromatic and 26π aromatic β-free pristine rosarin via redox reactions, which was not observed in distorted β-dodecamethyl rosarin.

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A highly distorted binuclear rhodium(I) complex, , was successfully synthesized from hexaphyrin(2.1.2.

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An insoluble thin film of a coronene diimide (CDI) derivative was fabricated from a soluble precursor of perylene diimide (PDI) by photoirradiation. We prepared a 1,7-diarylated PDI (TP-PDI) that can be converted into a coronene diimide (TP-CDI) derivative via a Scholl-type photocyclization reaction. This reaction was accompanied by structural changes from a twisted structure to a π-extended planar molecule.

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We demonstrate growth control of Cu-based metal-organic framework (MOF) (HKUST-1) thin films assembled by the layer-by-layer technique on polymer films. The crystallinity and crystal face of MOF thin films were found to be controlled by reaction sites in polymer films such as hydroxy groups (the (100) crystal face), carbonyl groups (the (111) crystal face), and amide groups (the (100) crystal face). The HKUST-1 film growth amount is highly correlated with the polar component of the surface free energy, indicating that polymer sites, which afford hydrogen and coordination bonding, are important for the initial adsorption of Cu complexes.

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Vinylene-bridged cyclic boron-difluoride complex of dipyrrin (BODIPY) trimers were successfully prepared from expanded dimethyl-vinylene bridged hexaphyrin(2.1.2.

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The nanoscale morphology of polymer blends is a key parameter to reach high efficiency in bulk heterojunction solar cells. Thereby, research typically focusing on optimal blend morphologies while studying nonoptimized blends may give insight into blend designs that can prove more robust against morphology defects. Here, we focus on the direct correlation of morphology and device performance of thieno[3,4-]-thiophene--benzodithiophene (PTB7):[6,6]phenyl C butyric acid methyl ester (PCBM) bulk heterojunction (BHJ) blends processed without additives in different donor/acceptor weight ratios.

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Naphthalene diimide (NDI)-biselenophene copolymer (PNDIBS), NDI-selenophene copolymer (PNDIS), and the fluorinated donor polymer PM6 were used to investigate how a fluorinated polymer component affects the morphology and performance of all-polymer solar cells (all-PSCs). Although the PM6:PNDIBS blend system exhibits a high open-circuit voltage ( = 0.925 V) and a desired low optical bandgap energy loss ( = 0.

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Herein, triplet-triplet annihilation upconversion (TTA-UC) from near-infrared (NIR, 785 nm) to visible (yellow, centered at 570 nm) regions has been demonstrated in the binary solid of condensed chromophores. Microparticles of the binary solid comprising rubrene as a matrix (emitter) and π-extended Pd-porphyrin as a dopant (sensitizer) in a mole ratio of 1000:1 were obtained by solution casting. Excitation intensity dependence and quantum yield (QY) of the upconverted emission were characterized for individual particles under a microscope and revealed a low threshold intensity (∼100 mW/cm) as compared to the solution and moderate UC-QY (∼0.

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Expanded porphyrins are attractive research targets because of their large and flexible structures, optical and electrochemical properties, and diverse coordination abilities. We are interested in the use of double bonds within expanded porphyrins because double bonds could conduct isomerization, expansion of π-conjugation, and giving different molecular geometry. We, thus, report [30]hexaphyrin(2.

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9,10-Quinoxaline-fused porphycenes and were synthesized by intramolecular McMurry coupling. As a result of the annulation of the quinoxaline moiety on the porphycene skeleton, and display absorption and fluorescence in the near infra-red (NIR) region. Additionally, the quinoxaline moieties of and act as electron-withdrawing groups, introducing lower reduction potentials than for pristine porphycene.

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Tetrabenzoporphyrin (BP) is a p-type organic semiconductor characterized by the large, rigid π-framework, excellent stability, and good photoabsorption capability. These characteristics make BP and its derivatives prominent active-layer components in organic electronic and optoelectronic devices. However, the control of the solid-state arrangement of BP frameworks, especially in solution-processed thin films, has not been intensively explored, and charge-carrier mobilities observed in BP-based materials have stayed relatively low as compared to those in the best organic molecular semiconductors.

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A sandwich complex of iridium(III) benzotriphyrin (2) has been synthesized from free-base benzotriphyrin (1) and [IrCl(cod)] (COD = 1,5-cyclooctadiene). The COD ring was transformed from 1,5-COD to an η,η-CH unit as a π-allyl ligand associated with the valence change of iridium from Ir to Ir, as revealed by X-ray diffraction analysis. The Soret-like band of 2 was blue-shifted and broadened compared with that of 1, indicating strong electronic interactions between triphyrin and the iridium ion.

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We prepared perylene dications 1(2+) and 2(2+) by using "capped" perylene derivatives, and for the first time, successfully obtained single crystals of a perylene dication 1(2+) that enabled us to perform its structural analysis. We realized that the substituted aryl groups on perylene control the positions of positive charges, thus the remaining electronic system satisfies Clar's sextet rule toward the highest number of localized sextets. Experimental and theoretical evidence proved that Clar's aromatic π-sextet rule could be applied even for the dicationic perylenes in a very simple way.

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